Can Fluorspar be replaced in steelmaking? Eugene Pretorius Baker Refractories

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Can Fluorspar be replaced in steelmaking? Eugene Pretorius Baker Refractories"

Transcription

1 Can Fluorspar be replaced in steelmaking? By Eugene Pretorius Baker Refractories

2 I) Introduction The use of fluorspar in steelmaking is a controversial issue. A number of studies have shown that there are considerable environmental concerns regarding the use of fluorspar, and some plants has opted not to use fluorspar for this very reason. While fluorspar has been banned as a deliberate additive to the slags in these plants, the presence of fluorspar in mold fluxes has not been eliminated. This technical note will not address any of the environmental concerns regarding the use of fluorspar but will only focus on the technical aspects of this component in steelmaking. An attempt is made to provide a better understanding on the behavior of fluorspar in slags and then discuss possible alternative to fluorspar in steelmaking slags. II) The role of fluorspar in steelmaking slags Fluorspar is utilized for the following reasons: 1. To increase the solubility of CaO in the slag and hence improve desulfurization of the steel. 2. To act as a fluxing precursor in ladle and stainless steel reduction slags. 3. To maintain fluidity in the slag as the slag temperature decreases (VOD and ladle slags). In simple silicate slags, the solubility of CaO is limited by the precipitation of the very stable phase, Ca 2 SiO 4. The following figures of the CaO-SiO 2 system shows that once the saturation point of CaO has been reached at a specific temperature, the addition of more CaO to the slag will rapidly decrease the fluidity of the slag. It is important to note that it is dissolved lime in the liquid portion of the slag that desulfurizes the steel. The addition of more lime to a CaO-saturated slag, results in a rapid decrease in slag fluidity, which will negatively effect desulfurization. Figure 1. Phase diagram of the CaO-SiO 2 system 1 2

3 This diagram has the following important features: 1. The composition of the CaO-saturated liquid at 1600 C is: % CaO 56 % SiO The equilibrium CaO-saturation phase in contact with this liquid is Ca 2 SiO 4, which has a melting point of 2130 C. 3. The solidus temperature of this liquid is about 1464 C. 4. The area of interest in this diagram has been circled and is shown in the next figure: Liquidus Boundary % CaO - 64 % SiO 2-36 C/S = C 2912 F C 2 S + L % CaO - 56 % SiO 2-44 C/S = 1.3 L 1460 C 2660 F CaO - Saturation Refractory compatible ( Creamy ) Figure 2. Enlarged area of the CaO-SiO 2 phase diagram This diagram shows the very small area of workable slags in this system. Slags with a basicity ratio (C/S) > 1.8 will be completely solid at steelmaking temperatures. The lever rule can be used to calculate the respective amounts of liquid and solid as shown in Figure 3. % Liquid C/S Ratio %Liq Figure 3. % Liquid as a function of basicity (CaO/SiO 2 ) in the CaO-SiO 2 system at 1600 C 3

4 From the above discussion it is clear that the Ca 2 SiO 4 phase is limiting the solubility of CaO in the slag. The addition of any component to the slag that will dissolve (destabilize) Ca 2 SiO 4, will increase the solubility of CaO in the slag. In the following figure the effect of the components B 2 O 3, Al 2 O 3, CaF 2 and FeO on the Ca 2 SiO 4 stability field, is demonstrated at 1600 C. SiO C B 2 O 3 CaF 2 Al 2 O 3 FeO Ca 2 SiO 4 B 2 O 3 CaO Al 2 O 3 CaF 2 FeO Figure 4. The effect of different oxides on the liquidus phase relations of the CaO-SiO 2 system at 1600 C This figure clearly shows that B 2 O 3 is the most potent flux to bring Ca 2 SiO 4 into solution, followed by CaF 2, then Al 2 O 3 and finally FeO (in most steelmaking slags iron oxide is predominately present as Fe 2+ ) III) Considering B 2 O 3 as a flux. Figure 4 shows that the addition of B 2 O 3 to a CaO-SiO 2 slag will result in a rapid increase in the solubility of CaO. The increase in CaO content as the B 2 O 3 level increase is almost a linear relationship and can be approximated by the following equation at 1600 C: % CaO 1600 C = 1.1 * %B 2 O (Applicable for B 2 O 3 levels up to 15%) 4

5 The effect of B 2 O 3 on the solubility of CaO and desulfurization is shown in the next table Table 1. The effect of B 2 O 3 on the solubility of CaO and desulfurization at 1600 C % CaO % SiO % B 2 O Optical Basicity Sulfide Capacity Sulfur Distribution Coeff Final Sulfur (%) Optical basicity, sulfide capacity correlations, and thermodynamic data were used to calculate the final sulfur in the steel. The following parameters were considered in the calculation: Temperature ( C) 1600 Slag Amount (kg) 2000 Metal Amount (kg) Initial Sulfur (%) 0.05 Oxygen Level in Steel (ppm) 15 B 2 O 3 and steelmaking concerns The stability of B is compared to a number of typical steel components in Table 2. Table 2. Thermodynamic stability of SiO 2, B 2 O 3, MnO, and Cr 2 O 3 at 1600 C Reaction G reaction at 1600 C (kj/mole) K eq at 1600 C Si + O 2 = SiO x /3 B + O 2 = 2/3 B 2 O 3(l) x Mn + O 2 = 2 MnO x /3 Cr + O 2 = 2/3 Cr 2 O x Table 2 shows that the stability of B is similar to that of Si and that a considerable amount of B could be dissolved in the steel under typical steelmaking conditions. While boron is a desirable element in some grades of steel, in other grades of steel it could be detrimental to the physical properties of the steel. The use of B 2 O 3 as a flux to increase the solubility of CaO would therefore be limited to boron-containing grades. Furthermore, the amount of B 2 O 3 that could be added to the slag will be limited by the amount of B that can be tolerated in the steel, and still care would be required, as control will not be easy. B 2 O 3 and Refractory concerns One of the biggest drawbacks of utilizing B 2 O 3 as flux in a slag, the potential for significant refractory erosion. B 2 O 3 is a more powerful flux than fluorspar to dissolve basic oxides (CaO & MgO) as evidenced by the very high solubility of the CaO and MgO in a pure B 2 O 3 liquid at 1600 C, which are 75% and 79%, respectively. 5

6 When B 2 O 3 is utilized as a fluxing component in slags in contact with doloma refractories, CaOsaturation is an important slag requirement, since fired doloma refractories are lime-bonded. It is also important to add the B 2 O 3 in a pre-mixed form because the addition of concentrated amounts of B 2 O 3 in one area of the slag could lead to significant localized refractory wear. CaO-saturation in the slag is achieved by adding lime to maintain a slag with a "creamy" consistency at all times. Maintaining MgO saturation in a slag is more difficult for a number of reasons. A MgO source such as doloma or magnesia is not always readily available as an additive to the slag. When doloma (~58 %CaO, 38% MgO) is used it is difficult to determine when the slag is MgO-saturated because the doloma addition can result in a slag with a "creamy" consistency that could be CaOsaturated but not MgO-saturated. Furthermore, for some grades of steel, slags with high MgO content is not desirable because of the potential of spinel (MgAl 2 O 4 ) inclusions in the steel. Any magnesia-based refractory could therefore be vulnerable to significant refractory wear if in contact with B 2 O 3 -containing slags. B 2 O 3 is used in mould fluxes as a fluxing agent for the CaO-SiO 2 basic system, but this is at much lower temperatures and the B 2 O 3 also has an effect on the overall crystallization tendency, which is important. IV) Considering CaF 2 as a flux After B 2 O 3, CaF 2 is the next strongest component to destabilize Ca 2 SiO 4 and increase the solubility of CaO in the slag. The phase diagram of the CaO-CaF 2 -SiO 2 system is shown in Figure 5. Figure 5. Phase diagram of the CaO-CaF 2 -SiO 2 system 1 6

7 The most striking feature of this diagram is the tremendous increase in the solubility of CaO, when CaF 2 is added to CaO-SiO 2 slags, or when SiO 2 is added to CaO-CaF 2 slags. The combined effect of SiO 2 and CaF 2 results in a high CaO solubility, as shown by point (a) on the diagram (1600 C). The composition of the slag at this point is approximately the following: % CaO 72 % SiO 2 17 % CaF 2 11 The saturation solubility of CaO at 1600 C in CaO-CaF 2 -SiO 2 system, is plotted as a function of SiO 2 content in Figure Slag (a) in Fig % CaO in Solution % SiO2 Figure 6. Solubility of CaO as a function of SiO 2 content in CaO-CaF 2 -SiO 2 slags at 1600 C The maximum in CaO solubility is at about 12% CaF 2 in the slag. The addition of more CaF 2 to the slag, results in a decrease in CaO solubility along the CaO-saturation boundary. This is because the SiO 2 content of the slag is diluted to below 17%. Again this shows why the maximum amount of fluorspar that would ever be required in a slag is 12%. The addition of more CaF 2 would also result in an increase in fluidity that could lead to increased refractory erosion. Utilizing fluorspar as a fluxing precursor Fluorspar is often used as fluxing precursor in stainless steel reduction slags. If fluorspar is added just before the reduction mix it will melt immediately and create some liquid in the slag so that when the reductant is added it will be immersed in a partially liquid slag. The generation of a small amount of early liquid slag could greatly enhance the reduction efficiencies and kinetics (due to increased mass transfer/diffusion rates). The typical aim CaF 2 levels in the final slag should be about 3%, provided the slag contains considerable amounts of MgO (approximately 10%). If the MgO content of the final slag is less than 10% then higher CaF 2 levels might be required to obtain adequate dissolution rates. 7

8 Utilizing Fluorspar to increase the solubility of CaO in the slag Fluorspar is most commonly added to slag in order to increase the solubility of CaO in the slag, and hence improve the desulfurization capacity of the slag. In the previous discussion on B 2 O 3 it was shown that any addition of B 2 O 3 will increase the solubility of CaO. The same is not true for fluorspar in the CaO-SiO 2 -CaF 2 system. The liquidus boundaries in Figures 4 and 5 show that a significant increase in lime solubility will only occur when the CaF 2 content of the slag exceeds about 12% at 1600 C. Furthermore, the increase in CaO solubility at "constant" CaF 2 content is strongly dependent on the SiO 2 content of the slag. The CaO solubility only increases as the SiO 2 content of the slag is decreased. Figure 7 shows the solubility of CaO as a function of the CaF 2 /(SiO 2 + CaF 2 ) ratio in the slag % CaO - 72 % SiO2-17 % CaF2-11 % CaO at Saturation % CaF % CaO - 54 % SiO2-31 % CaF %CaF2/(%SiO2+%CaF2) 0% SiO2 Figure 7. The solubility of CaO as a function of the CaF 2 and SiO 2 content of the slag. The CaF 2 contents of each of the slags are shown on the figure. In more complex steelmaking slags that also contain considerable amounts of MgO, the "minimum" level of CaF 2 required to result in an increase in CaO solubility will probably be much less. The increase in CaO solubility with increasing CaF 2 content might even be linear, similar to B 2 O 3. CaF 2 is also a very good flux for MgO and any increase in the solubility of MgO, because of CaF 2 addition, will also increase CaO solubility. This is because an increase in MgO solubility will shift the dual saturation point downward towards the CaO-MgO boundary of the diagram. Furthermore, the presence of MgO in the slag limits the stability of Ca 2 SiO 4 by the formation of CaMg-silicate phases and therefore acts as a flux for Ca 2 SiO 4. 8

9 The phase relations for the CaO-MgO-SiO 2 -CaF 2 system at 1600 C were inferred from available CaF 2 -containing binary and ternary diagrams, and are shown in the next figure. SiO 2 + CaF S+L Ca 2 SiO 4 70 Ca 3 SiO % CaF 2 8% CaF 2 12% CaF 2 Mg 2 SiO CaO Figure 8. The system CaO-MgO-SiO2-CaF 2 at 1600 C MgO This diagram shows the following important features: 1. An increase in CaO solubility as the CaF 2 content of the slag increases 2. A decrease in CaO solubility on the CaO-saturation curve as the MgO content of the slag increases towards dual saturation. 3. An increase in MgO solubility at dual saturation as the CaF 2 content of the slag increases. One of the most important features of this diagram is the increase in MgO solubility (at dual saturation) as the CaF 2 content of the slag increases. This has significant implications for magnesia-based slaglines. If fluorspar-containing slags are in contact with magnesia refractories, then significant refractory wear can occur if the slag is not MgO or CaO saturated. If the slag is CaO-saturated but MgO-unsaturated ( creamy consistency), then the extent of refractory wear could be minimized even though the slag is not fully chemically compatible with the refractories. However, if the slag is also CaO unsaturated (very liquid or watery in consistency) then severe refractory wear can occur in just one heat. The above is true for any slag, CaF 2 -containing or not, but the presence of CaF 2 accelerates the wear because of its depression of the solidus temperature of the slag, which causes deeper penetration into the refractory matrix. For some stainless steel grades with very low sulfur specifications, a second reduction slag might be required in the converter. Typically a mixture of lime and fluorspar is utilized. From Figures 9

10 5-7 it is clear that the amount of residual slag in the vessel, in combination with the lime and fluorspar additions, can yield slags with high desulfurization capabilities. Utilizing fluorspar to maintain slag fluidity In VOD operations all the reduction slags stays in the ladle until the steel is cast. An important requirement is that the slag stays reasonably liquid down to casting temperatures to facilitate alloy and wire additions. When all the fluorspar is added in a single step during reduction for fluidity control, then extensive slagline refractory wear will occur. The preferred method is to add the fluorspar in steps after reduction as the slag cools, and only as needed. This could result in significant refractory performance improvements and also decreased fluorspar consumption. The effect of fluorspar in aluminate slags Fluorspar can be very effective in increasing the solubility of CaO in silicate slags but it is not very effective in terms of increasing CaO solubility in aluminate slags (discussed later). The only benefit fluorspar could have for Al-killed grades is that it could act as the fluxing precursor before the Al is added. In these grades fluorspar is not normally necessary because the reaction of CaO and Al 2 O 3 will form a liquid slag without high-melting intermediate phases such as Ca 2 SiO 4. The only intermediate phase that can form, Ca 3 Al 2 O 6, melts at 1535 C Fluorspar and steel quality concerns The elemental constituents of CaF 2, Ca and F, has a very low solubility in steel so that there are negligible interactions between CaF 2 in the slag and the steel. This is in contrast to B 2 O 3 and Al 2 O 3 where significant slag-metal interactions are possible. The lack of slag/metal interaction of the F - with the steel is probably one of the main reasons why fluorspar is so popular as a fluidizing agent. Fluorspar and Refractory concerns In the previous discussion it was clearly shown that fluorspar in combination with SiO 2 is a very potent flux to bring CaO into solution. If lime is added to the slag until the slag is CaO-saturated there will be minimal refractory wear on lime-bonded (dolomite) refractories. However, if additional lime for saturation was not added, the presence of fluorspar in the slag could lead to accelerated refractory wear. This slag will have a lower viscosity, a lower solidus temperature and a high capacity to bring lime into solution and will lead to a deeper slag penetration into the refractory and increased refractory wear. It is important to note that it is not the presence of CaF 2 that causes refractory wear in CaO-bonded refractories but the lack of lime saturation. A very liquid silicate or aluminate slag that is CaO unsaturated, and contains no CaF 2, will also be very aggressive to the refractories. The addition of fluorspar to silicate and aluminate slags also results in an increase in the solubility of MgO in the slag (Figure 8) 2. This increase in MgO solubility could lead to significant refractory wear if additional MgO is not added to the slag or if CaO-saturation is not maintained at all times. Most steelmaking refining slags are not MgO-saturated, because only lime is typically 10

11 available as an additive. Furthermore, the very high levels of MgO required for saturation might be undesirable from a steel quality perspective. High MgO slags in contact with steel with low oxygen content could result in Mg pickup in the steel and lead to spinel inclusion formation in the steel. Based on the discussion above, it is clear that dolomite refractories might be more compatible in contact with fluorspar containing slags than magnesia-based refractories. The simple reason is that lime saturation (a dolomite refractory requirement) is much easier to achieve in practical steelmaking than MgO saturation, or dual saturation. V) Consider Al 2 O 3 as a flux From Figure 3 it can be seen that Al 2 O 3 is the third "best" component to destabilize Ca 2 SiO 4 and increase the solubility of CaO. This figure also shows that a significant minimum amount of Al 2 O 3 would be required to result in an increase in CaO solubility at 1600 C. The increase in CaO solubility above the Al 2 O 3 threshold value is also linked to the SiO 2 content of the slag, similar to the case with CaF 2 (Figure 9) % CaO % SiO2-9.6 % Al2O % CaO at saturation % Al2O3 % CaO % SiO % Al2O % SiO Al2O3/(SiO2+Al2O3) Figure 9. The solubility of CaO as Al 2 O 3 is replacing SiO 2 at 1600 C (2912 F) This figure shows that in the CaO-Al 2 O 3 -SiO 2 (CAS) system, the replacement of SiO 2 with Al 2 O 3 will initially result in a decrease in CaO solubility. A large increase in CaO solubility only occurs when the Al 2 O 3 content of the slag exceeds about 25% Al 2 O 3 and the SiO 2 content of the slag decreases from about 23% to 10% SiO 2. 11

12 Figure 9 clearly shows the interdependence of the CaO solubility on the SiO 2 and Al 2 O 3 levels of the slag. The impact of these relationships is very significant on stainless steel production. In stainless steelmaking the Al 2 O 3 in slag is generated by the partial replacement of FeSi by Al as a reductant, or FeSi containing high levels of Al. It is therefore very important to do an accurate mass-balance calculation to ensure proper Al/Si reductant ratios in order to achieve the target fluidity and desired CaO solubility. From the evaluation of the CaO-SiO 2 -CaF 2 and CaO-Al 2 O 3 -SiO 2 systems, it is clear that Al 2 O 3 is not as potent as CaF 2 to bring lime into solution, and considerably higher levels of Al 2 O 3 would be required in the slag to get the same amount of CaO into solution. Most steelmaking slags also contain MgO so that consideration of the phase relations in the CaO- MgO-Al 2 O 3 -SiO 2 (CMAS) system is very important. Fortunately, this system is well studied and the "ternary isoplethal sections" at constant MgO and Al 2 O 3 content are available. Evaluation of the CaO-MgO-Al 2 O 3 -SiO 2 system at constant MgO levels Figure 10 shows the saturation levels of CaO at 1600 C as a function of the Al 2 O 3 /(SiO 2 + Al 2 O 3 ) ratio for slags containing MgO levels of 0%, 5% and 10%, respectively. % CaO at Saturation % MgO 5% MgO 10% MgO % Al 2 O 3 = (A) (B) % Al 2 O 3 /(% SiO 2 + % Al 2 O 3 ) Figure 10. The solubility of CaO as a function of Al 2 O 3 content at 1600 C (The actual Al 2 O 3 levels of the slags are indicated in the figure) 12

13 This figure has the following important features: The solubility of CaO initially decreases as Al 2 O 3 replaces SiO 2 as flux. For slags with a (%Al 2 O 3 /(%SiO 2 + %Al 2 O 3 ) ratio < 0.5 the solubility of CaO decreases as the MgO content of the slag increases. However, at ratio of about 0.5, the amount of CaO in solution is the same for MgO levels from 0-10%, indicating that MgO is acting as flux in this composition region, because total base in solution (MgO + CaO) increased. In practical terms, the %CaO/(%SiO 2 + %Al 2 O 3 ) ratio in the slag increases significantly as the MgO content of the slag increases from 0 10% at a (%Al 2 O 3 /(%SiO 2 + %Al 2 O 3 ) ratio of about 0.5. The minimum threshold Al 2 O 3 level required in the slag before an increase in CaO solubility is realized, decreases with increasing MgO content in the slag. At 0% MgO the minimum Al 2 O 3 threshold value is about 27%, for 5% MgO the Al 2 O 3 level required is about 22%, and for 10% MgO the Al 2 O 3 level required is about 15%. In all these cases the solubility of CaO only increases when the SiO 2 content of the slag is diluted. For example consider slags (A) and (B) in Figure 10 that contain 22.5 and 23% Al 2 O 3, respectively (5% MgO). Slag (A) contains 22.5% SiO 2 and only has 50% CaO in solution, whereas slag (b), which contains only 12% SiO 2, has 59% CaO in solution. This has a significant implication in terms of desulfurization. Not only are high levels of Al 2 O 3 required in the slag (>22%), but the SiO 2 level should be below 15%. These lower levels of SiO 2, together with the higher levels of [Al], will result in a decreased oxygen potential in the steel. For slags containing 10% MgO, the solubility of CaO increases when the Al 2 O 3 content of the slag exceeds about 15%. However, at an Al 2 O 3 level of approximately 20%, the solubility of CaO decreases, as the slags are now MgO saturated. From the quaternary system it can be determined that the maximum MgO level of the slag should be below 7.5 % to obtain the high CaO solubilities shown in Figure 10. Evaluation of the CaO-MgO-Al 2 O 3 -SiO 2 system at constant Al 2 O 3 levels The slags and phase relations discussed so far were all at a temperature of 1600 C (2912 F). However, it is also important to consider the phase relations at higher temperature since some steelmaking process routes operate at much higher temperatures. For example, in stainless steelmaking operations the reduction temperatures are typically around 1700 C (3092 F), while the typical tapping temperatures from the stainless steel vessel are much lower ( ). This large difference in the end of reduction temperature and the tapping temperature causes significant problems in engineering refractory compatible slags that are also "workable" in the stainless steel vessel. A slag that is designed to be liquid and compatible with the refractories at 1700 C might become too stiff at tapping temperatures. Alternatively, a slag designed to stay liquid down to tapping temperatures could cause significant refractory wear during reduction step when temperatures and turbulence in the vessel are high. Some slag regions in the CaO-MgO-SiO 2 - Al 2 O 3 system further intensify this problem, as will be demonstrated by the following discussion. In the CaO-MgO-SiO 2 system, and the CaO-MgO-SiO 2 -Al 2 O 3 system, MgO is acting as fluxing component until the MgO saturation boundary is reached. For example in the CaO-SiO 2 system, the solubility of basic oxide (CaO) is about 56% CaO at 1600 C, whereas in the CaO-MgO-SiO 2, the solubility of basic oxides (CaO + MgO) is about 61% at dual saturation (saturated with both CaO & MgO). Figure 11 shows the effect of MgO on the total base solubility (CaO + MgO) in the CMAS system. A significant shrinkage of the Ca 2 SiO 4 stability field can be observed as the MgO content of the slag increases. Also important to note is that the solubility of the basic oxides (primarily CaO) is much higher in the stability areas of Ca 3 SiO 5 and lime (CaO). 13

14 The slag compositions that are of particular interest in this system are those that are dual saturated with respect to both MgO and CaO. The CaO-saturation phase could be Ca 2 SiO 4, Ca 3 SiO 5, or CaO depending on the temperature and Al 2 O 3 content. Figure 11. Saturation lines of CaO, Ca 2 SiO 4, and Ca 3 SiO 5 in the system CaO-MgO-SiO 2 -Al 2 O 3 at 1600 C and for MgO contents up to 16%. 1 Phase relations at the 10% Al 2 O 3 plane For slags containing less than 10% Al 2 O 3, the phase relations are similar at 1600 C and 1700 C, i.e., the solubility of CaO decreases with increasing Al 2 O 3 content (Figure 10). However, for Al 2 O 3 levels at, and greater than about 10%, an small area of high CaO solubility opens up at 1700 C as shown in Figure 12. Three slags of particular interest on this diagram are labeled a, b, and c and their compositions are listed in the table below. Table 3. Slag compositions in the CaO-MgO-SiO 2 -Al 2 O 3 system at 1600 and 1700 C Slag (a) Slag (b) Slag (c) Temperature 1700 C 1700 C 1600 C % CaO % MgO % SiO % Al 2 O Equilibrium phases on the liquidus boundary Ca 3 SiO 5 + MgO Ca 2 SiO 4 + MgO Ca 2 SiO 4 + MgO 14

15 SiO 2 10% Al 2 O 3 50% 1600 C 60% c a b 1700 C CaO 10% 20% MgO Figure 12. Isothermal sections of the CaO-MgO-SiO 2 -Al 2 O 3 system through the 10% Al 2 O 3 plane and temperatures of 1600 and 1700 C Slags (a) and (b) have similar Al 2 O 3 and MgO levels, but show a significant increase in CaO solubility as the SiO 2 content decreases from 27% (slag b) to 20% (slag a). This further highlights the importance of careful mass-balance calculations of reductant and alloy additives to obtain the desired slag compositions. If slag (a) was targeted for desulfurization reasons at high temperatures, it will become very stiff and unworkable at the 1600 C because the CaO solubility decreased from 59% to 46% over a 100 C interval. Furthermore, this small window of high CaO solubility at 1700 C is only present in a very small MgO range (11-12%). It is very difficult to control the MgO content of the slag that accurately under real steelmaking conditions. Phase relations at the 15% Al 2 O 3 plane The phase relations in the CMAS system in the 15% Al 2 O 3 plane are shown in Figure 13. At this Al 2 O 3 level the window of high CaO solubility at 1700 C has opened up considerably, but a small window of high CaO solubility is now evident at 1600 C. On the 1700 C isotherm, the CaOsaturated phase in equilibrium with the liquid changes from Ca 2 SiO 4, to Ca 3 SiO 5 (g to h) and finally to CaO (h to d). At point (d) the slag is dual saturated with respect to CaO and MgO. 15

16 SiO 2 15% Al 2 O C 1700 C 50% 60% f g h e d CaO 10% 20% MgO Figure 13. Isothermal sections of the CaO-MgO-SiO 2 -Al 2 O 3 system through the 10% Al 2 O 3 plane and temperatures of 1600 and 1700 C Figure 12 and 13 show that MgO has a very important overall fluxing effect in the system by opening a "window" of slags with high CaO solubility. However, from a more detailed perspective, the solubility of CaO actually decreases with increasing MgO content on the 1700 C liquidus isotherm where lime is the equilibrium solid phase (points (h) to (d)). The following table is comparison of CaO-saturated slags in the CAS system and the CMAS system (15% Al 2 O 3 ) at 1600 and 1700 C. This table shows that at 1700 C and 15% Al 2 O 3, the right combination of MgO and SiO 2 can result in slags with a high dissolved CaO content at Al 2 O 3 levels much lower than in the CAS system (27.7% Al 2 O 3 ). Table 4. The maximum solubility of CaO in the CAS and CMAS systems Temperature 1600 C 1600 C (e) 1600 C (f) 1700 C 1700 C System CAS CMAS CMAS CAS CMAS % CaO % MgO % SiO % Al 2 O

17 While the "slag window" for high CaO slags at 1700 C is not that sensitive to MgO levels (5-12%), it is much more sensitive at 1600 C (9-11% MgO). The following conclusion can be drawn from the above diagrams: Good desulfurizing slags (high dissolved CaO content) can be generated with slags containing low levels of Al 2 O 3 (12-15%) at 1700 C, and to some extent at 1600 C. However, the fluidity of these slags are very sensitive to changes in MgO contents and could became very stiff at lower temperatures (1600 C) if the composition of the slag is not carefully controlled. These diagrams further show that if the slags are designed to be liquid at 1600 C (point f in Figure 13), then significant refractory wear of doloma based refractories can occur if these slags are in contact with the brick at 1700 C or higher. The bonding phase in fired doloma refractories is lime (CaO) and Figure 13 and Table 4 show that the solubility of CaO increases from 46% to 62% for a temperature increase from 1600 C to 1700 C. Phase relations at the 20% and 25 Al 2 O 3 planes The small "windows" of slags areas that had high CaO-solubilities at 10% and 15% Al 2 O 3 have "opened" significantly at 20 Al 2 O 3 and opened completely at 25% Al 2 O 3 (Figure 14 and 15). SiO 2 20% Al 2 O C 50% 1700 C 60% CaO 10% 20% Figure 14. Isothermal sections of the CaO-MgO-SiO 2 -Al 2 O 3 system through the 20% Al 2 O 3 plane and temperatures of 1600 and 1700 C MgO 17

18 SiO 2 25% Al 2 O C 1700 C 50% 60% i j CaO 10% 20% Figure 15. Isothermal sections of the CaO-MgO-SiO 2 -Al 2 O 3 system through the 25% Al 2 O 3 plane and temperatures of 1600 and 1700 C MgO These figures clearly show that the combination of MgO and Al 2 O 3 results in a "shrinkage" of the Ca 2 SiO 4 stability field which opens up an area of slags with high CaO solubility. However, on the lime-saturated liquidus boundaries, the solubility of CaO decreases with increasing MgO content. For example, on the 1700 C liquidus boundary the solubility of CaO decreases from about 64% (0% MgO at point (i)) to about 56% where the slag is dual saturated (11% MgO at point (j)). Another interesting feature of these diagrams is the MgO content of the slag at dual saturation for the various Al 2 O 3 levels. The solubility of MgO (at dual saturation) initially decreased with increasing Al 2 O 3 content up to about 20% Al 2 O 3, but then increases again at higher Al 2 O 3 levels. 18

19 Utilizing Al 2 O 3 to increase the solubility of CaO in the slag The discussion of the phase relations in the CAS and CMAS systems have clearly shown that Al 2 O 3 could be utilized to increase the solubility of CaO in the slag. While it is theoretically possible to generate slags with a high dissolved CaO content at Al 2 O 3 levels as low as 15% at 1700 C it would be difficult to consistently generate these slags under real steelmaking conditions. More realistic Al 2 O 3 levels in the slag should be 20-25% Al 2 O 3 (preferably 25%) in order to generate slags with good fluidity at lower temperatures. The diagrams of the CMAS system also showed the importance of MgO as a fluxing component to generate slags with high dissolved lime contents. The MgO content of the slag is very important in this system and should be controlled in a very tight range (8-11% MgO). Too low or too high MgO levels could result in very stiff slags with poor desulfurizing properties. The discussion of the diagrams also demonstrated the importance of the SiO 2 content of the slag and its relationship with Al 2 O 3 on the solubility of CaO. The solubility of CaO increases rapidly as the SiO 2 content of the slags is diluted at constant Al 2 O 3 (Figures 10, 14 and 15). Al 2 O 3 and steel quality concerns In practical steelmaking, the levels of Al 2 O 3 required to generate slags with high CaO solubilities is >20% Al 2 O 3. This means that the bulk of the steel deoxidant or reductant should be Al. Partial replacement of FeSi by Al as a reductant in stainless steelmaking will be ineffective to increase the solubility of CaO. Another important factor is the SiO 2 content of the slag. The SiO 2 that is transferred from the EAF slag, together with the transfer Si and Si in alloy additions, must be considered to determine the Al required in the reduction mix to ensure adequate SiO 2 dilution (<15%). The use of Al as a deoxidizer and reductant, and the resulting high Al 2 O 3 slags, will have a large effect on the internal quality of the steel. The residual Al levels in the steel and the resultant lower dissolved oxygen level will have a significant impact on the inclusion chemistry and the timing of Al 2 O 3 precipitation. The previous discussion on the CMAS system clearly demonstrated the importance of MgO as flux in this system and that between 6 and 9% MgO would be required to enhance lime dissolution. Unfortunately, the maximum solubility of MgO in these high Al 2 O 3 slags is low (<11% MgO) so that slags with high MgO activities will be exposed to Al under fairly reducing conditions. The potential for Mg reduction and spinel formation is a real possibility. Al 2 O 3 and Refractory concerns The replacement of FeSi by Al in stainless steelmaking will result in higher reduction temperatures, which will require more coolant additions. If these coolants are not added and high temperatures (>1700 C) are prevalent during the reduction step, then significant refractory wear of doloma refractories can occur with slags with intermediate Al 2 O 3 levels (10-20% Al 2 O 3 ). The addition of sufficient lime to the slag to protect the refractories will result in liquid compatible slags at high temperatures but very stiff "unworkable" slags at lower temperatures. It is much easier to design refractory compatible and "workable" slags if the Al 2 O 3 content of the slag is between 25 and 30% Al 2 O 3. These slags are less sensitive to variations in MgO levels and the 19

20 1600 and 1700 C liquidus isotherms are closer together resulting in reasonable slag fluidity as the slag cools down. The following table summarizes the recommended target slag compositions in the CaO-MgO- Al 2 O 3 -SiO 2 system. Table 5. Target slag compositions and ranges in the CMAS system Al 2 O 3 range Comments 0 10% Al 2 O 3 No benefits in terms of CaO solubility. CaO solubility actually decreases as Al is replacing FeSi 10-20% Al 2 O 3 A very large increase in CaO solubility occurs in very specific slag areas. These slags are difficult to obtain and control under real steelmaking conditions. These slags could lead to significant refractory wear or alternatively very stiff unworkable slags at lower temperatures. It is best to avoid this slag composition range! 20 30% Al 2 O 3 The ideal target range is 25 to 30% Al 2 O 3. These slags can be designed to be refractory compatible with reasonable fluidity at lower temperatures VI) Summary and Conclusions This technical note has attempted to provide a better understanding on the effect of the fluxing components CaF 2, B 2 O 3, and Al 2 O 3 on the solubility of CaO in steelmaking slags. Fluorspar is by far the most convenient component to use as a fluxing precursor and additive to increase the solubility of CaO in the slag. The maximum levels of CaF 2 that would be required to obtain the maximum CaO solubility is about 12% CaF 2. Most operations could operate with slags with much lower CaF 2 levels, provided that some MgO is present in the slag (> 6% MgO). An important consideration is that the effect of CaF 2 on steel quality is negligible and it is practically inert to the steel. Refractory compatible slags can be designed for fluorspar-containing slags at high temperatures that will still maintain reasonable fluidity at lower temperatures. B 2 O 3 is the most potent of all three fluxes considered, not only in terms CaO solubility, but also in terms of refractory wear. The addition of B 2 O 3 as a flux is only an option in B-containing steel grades and great care should be exercised to ensure refractory compatibility. Alumina is a major slag component (> 25% Al 2 O 3 ) in Al-killed grades and is very effective to bring lime into solution and to generate good desulfurizing slags. Magnesia-carbon refractories are typically used with these slags and with good results because the solubility of MgO in these slags is fairly low (< 11% MgO). The use of Al 2 O 3 as a flux (prefused Ca-Aluminate) in low-c Si-killed steel grades is common and very effective. However, in high-c grades the level of Al 2 O 3 that can be tolerated in the slag is low (<10 % Al 2 O 3 ) because of castability issues (clogging). At these low levels, Al 2 O 3 is actually worse than SiO 2 to dissolve CaO and the only benefit is that it can act as a fluxing precursor if added as prefused Ca-Aluminate. Unfortunately, these high-c steel grades also have low sulfur requirements. In most cases a combination of SiO 2 and CaF 2 is used as fluxing additives to these grades to create slags with good desulfurization properties 20

21 without negative castability effects. The only alternative to using CaF 2 in the slags of these grades is to use scrap with very low sulfur levels. Fluorspar is commonly used in combination with FeSi in stainless steel operations as a fluxing precursor during the reduction step, and to increase the solubility of lime in the final reduction slag. The elimination of CaF 2 and the partial replacement of FeSi by Al will not be effective in improving reduction kinetics and increasing CaO solubility. For Al 2 O 3 to be effective in these slags, Al should be the bulk reductant addition and the FeSi addition and SiO 2 content of the slag should be carefully controlled. For these aluminate slags to be equivalent to a 8-10% CaF 2 - containing silicate slags in terms of lime dissolution and solubility, the Al 2 O 3 content of the slag should be around 25% Al 2 O 3. VII) References 1. Slag Atlas, edited by Verein Deutscher Eisenhüttenleute (VDEh). Verlag Stahleisen GmbH 2. Pretorius, E.B. "The effect fluorspar in steelmaking slags". Unpublished technical document. 21

FUNDAMENTALS OF EAF AND LADLE SLAGS AND LADLE REFINING PRINCIPLES. Eugene Pretorius Baker Refractories

FUNDAMENTALS OF EAF AND LADLE SLAGS AND LADLE REFINING PRINCIPLES. Eugene Pretorius Baker Refractories FUNDAMENTALS OF EAF AND LADLE SLAGS AND LADLE REFINING PRINCIPLES By Eugene Pretorius Baker Refractories Epretorius@bakerref.com 1 I) Introduction TABLE OF CONTENTS II) Introduction to slag fundamentals

More information

EAF REFRACTORY PERFORMANCE AT PACIFIC STEEL NEW ZEALAND

EAF REFRACTORY PERFORMANCE AT PACIFIC STEEL NEW ZEALAND EAF REFRACTORY PERFORMANCE AT PACIFIC STEEL NEW ZEALAND Don Sanford Product Manager Refractories Chemiplas, New Zealand Ltd Level 2, 42 Upper Queen Street Auckland, New Zealand DonS@chemiplas.co.nz Brian

More information

Electric Arc Furnace Simulation User Guide Version 1

Electric Arc Furnace Simulation User Guide Version 1 Electric Arc Furnace Simulation User Guide Version 1 1 Introduction and Disclaimer...2 2 Introduction to Electric Arc Furnace Steelmaking...2 2.1 Basic Concepts... 2 2.2 Heating and Melting... 2 2.3 Other

More information

RECYCLING PRACTICES OF SPENT MgO-C REFRACTORIES

RECYCLING PRACTICES OF SPENT MgO-C REFRACTORIES Journal of Minerals & Materials Characterization & Engineering, Vol. 1, No.2, pp69-78, 2002 Printed in the USA. All rights reserved RECYCLING PRACTICES OF SPENT MgO-C REFRACTORIES Kyei-Sing Kwong and James

More information

SECONDARY STEELMAKING

SECONDARY STEELMAKING 1 SECONDARY STEELMAKING Using a thermodynamic database and Researchers at Steel Authority of India Ltd (SAIL) have been using thermodynamic databases and FactSage 6.4 software to optimise the parameters

More information

Lecture 14 Modern trends in BOF steelmaking

Lecture 14 Modern trends in BOF steelmaking Lecture 14 Modern trends in BOF steelmaking Contents: Post combustion Technology of post combustion Potential post combustion issues Slag splashing What is required for slag splashing Liquidus temperature

More information

Effect of Charge Materials on Slag Formation in Ductile Iron Melts

Effect of Charge Materials on Slag Formation in Ductile Iron Melts Effect of Charge Materials on Slag Formation in Ductile Iron Melts C. Labrecque, M. Gagné and E. Planque Rio Tinto Iron & Titanium Inc. Sorel-Tracy, Quebec, Canada ABSTRACT The formation of an oxide slag

More information

RECOVERY OF CHROMIUM FROM STAINLESS STEEL SLAGS

RECOVERY OF CHROMIUM FROM STAINLESS STEEL SLAGS MultiScience - XXX. microcad International Multidisciplinary Scientific Conference University of Miskolc, Hungary, 21-22 April 2016, ISBN 978-963-358-113-1 RECOVERY OF CHROMIUM FROM STAINLESS STEEL SLAGS

More information

Activities of SiO 2 in Some CaO Al 2 O 3 SiO 2 ( 10%MgO) Melts with Low SiO 2 Contents at K

Activities of SiO 2 in Some CaO Al 2 O 3 SiO 2 ( 10%MgO) Melts with Low SiO 2 Contents at K ISIJ International, Vol. 47 (007), No. 6, pp. 805 810 Activities of SiO in Some CaO Al O 3 SiO ( 10%MgO) Melts with Low SiO Contents at 1 873 K YoungJo KANG, 1) Du SICHEN ) and Kazuki MORITA 3) 1) Graduate

More information

Corrosion of Nozzle Refractories by Liquid Inclusion in High Oxygen Steels

Corrosion of Nozzle Refractories by Liquid Inclusion in High Oxygen Steels , pp. 1281 1288 Corrosion of Nozzle Refractories by Liquid Inclusion in High Oxygen Steels Mun-Kyu CHO 1) and In-Ho JUNG 2) 1) Research Institute of Industrial Science and Technology, Pohang, Republic

More information

THE EFFECT OF ALUMINA IN FERROMANGANESE SLAG

THE EFFECT OF ALUMINA IN FERROMANGANESE SLAG THE EFFECT OF ALUMINA IN FERROMANGANESE SLAG Kai Tang and Sverre Olsen 1 SINTEF Materials and Chemistry, Trondheim, Norway, kai.tang@sintef.no 1 Department of Materials Technology, Norwegian University

More information

EAF burdening How can EAF burdening best utilise DRI? Rutger Gyllenram Kobolde & Partners

EAF burdening How can EAF burdening best utilise DRI? Rutger Gyllenram Kobolde & Partners EAF burdening How can EAF burdening best utilise DRI? Rutger Gyllenram Kobolde & Partners www.kobolde.com Disclaimer Examples given in this presentation are just examples, given in order to illustrate

More information

Lecture 17 Alternative Charge Materials in EAF

Lecture 17 Alternative Charge Materials in EAF Lecture 17 Alternative Charge Materials in EAF Contents: Introduction Types of metallic charge materials Carbon content in DRI Charging methods Key words: Sponge iron, DRI, electric arc furnace, UHP furnaces

More information

THE INFLUENCE OF BRIQUETTED SYNTHETIC SLAGS ON STEEL REFINING IN LADLE

THE INFLUENCE OF BRIQUETTED SYNTHETIC SLAGS ON STEEL REFINING IN LADLE Acta Metall. Slovaca Conf. 189 THE INFLUENCE OF BRIQUETTED SYNTHETIC SLAGS ON STEEL REFINING IN LADLE Ladislav Socha 1)*, Jiří Bažan 1), Pavel Machovčák 2), Aleš Opler 2), Petr Styrnal 3) 1) VŠB Technical

More information

Sulphur bonding in solidified ladle slags

Sulphur bonding in solidified ladle slags POSCH, W., PREβLINGER, H., MAYR, M., KLEPP, K., and HIEBLER, H. Sulphur bonding in solidified ladle slags. VII International Conference on Molten Slags Fluxes and Salts, The South African Institute of

More information

Briquette Smelting in Electric Arc Furnace to Recycle Wastes from Stainless Steel Production

Briquette Smelting in Electric Arc Furnace to Recycle Wastes from Stainless Steel Production Briquette Smelting in Electric Arc Furnace to Recycle Wastes from Stainless Steel Production Qi-xing YANG 1 2 2, Dong-feng HE 2 3 1 Abstract: Wastes from stainless steel production were briquetted together

More information

Part III: Slag Practices and Oxygen/Carbon Injection when Melting Direct Reduced Iron

Part III: Slag Practices and Oxygen/Carbon Injection when Melting Direct Reduced Iron Use of DRI in EAF s Gregory L. Dressel Dressel Technologies Pawleys Island, SC Part III: Slag Practices and Oxygen/Carbon Injection when Melting Direct Reduced Iron Introduction When melting DRI or HBI

More information

MgO modification of slag from stainless steelmaking

MgO modification of slag from stainless steelmaking ERIKSSON, J and BJÖRKMAN, B. MgO modification of slag from stainless steelmaking. VII International Conference on Molten Slags Fluxes and Salts, The South African Institute of Mining and Metallurgy, 2004.

More information

Thermodynamic database of P 2 O 5 -containing oxide system for De-P process in steelmaking

Thermodynamic database of P 2 O 5 -containing oxide system for De-P process in steelmaking Thermodynamic database of P 2 O 5 -containing oxide system for De-P process in steelmaking *In-Ho JUNG, Pierre HUDON, Wan-Yi KIM, Marie-Aline VAN ENDE, Miftaur RAHMAN, Gabriel Garcia CURIEL, Elmira Moosavi

More information

Effect of Silicon Carbide on Reactions between Molten Steel and Fused Magnesia Silicon Carbide Composite Refractory

Effect of Silicon Carbide on Reactions between Molten Steel and Fused Magnesia Silicon Carbide Composite Refractory Effect of Silicon Carbide on Reactions between Molten Steel and Fused Magnesia Silicon Carbide Composite Refractory Interactions between MgO SiC composite and liquid steel resulted in decomposition of

More information

Formation of MgO Al 2 O 3 Inclusions in High Strength Alloyed Structural Steel Refined by CaO SiO 2 Al 2 O 3 MgO Slag

Formation of MgO Al 2 O 3 Inclusions in High Strength Alloyed Structural Steel Refined by CaO SiO 2 Al 2 O 3 MgO Slag , pp. 885 890 Formation of MgO Al 2 O 3 Inclusions in High Strength Alloyed Structural Steel Refined by CaO SiO 2 Al 2 O 3 MgO Slag Min JIANG, Xinhua WANG, Bin CHEN and Wanjun WANG School of Metallurgical

More information

Analysis of parameters affecting end blow manganese content at oxygen steelmaking

Analysis of parameters affecting end blow manganese content at oxygen steelmaking Celso Dias Barão (Barão Consultoria Empresarial) Carlos Antônio da Silva, Itavahn Alves da Silva (Universidade Federal de Ouro Preto - UFOP) Analysis of parameters affecting end blow manganese content

More information

Evaluation of Viscosity of Molten SiO_2-CaO-MgO- Al_2O_3 Slags in Blast Furnace Operation

Evaluation of Viscosity of Molten SiO_2-CaO-MgO- Al_2O_3 Slags in Blast Furnace Operation Title Author(s) Citation Evaluation of Viscosity of Molten SiO_2-CaO-MgO- Al_2O_3 Slags in Blast Furnace Operation Nakamoto, Masashi; Tanaka, Toshihiro; Lee, Joonho; Usui, Tateo ISIJ International. 44(12)

More information

GTOX. a multipurpose oxide + database. GTT Users Meeting, Herzogenrath K. Hack 1, T. Jantzen 1, Elena Yazhenskhik 2, Michael Müller 2

GTOX. a multipurpose oxide + database. GTT Users Meeting, Herzogenrath K. Hack 1, T. Jantzen 1, Elena Yazhenskhik 2, Michael Müller 2 GTOX a multipurpose oxide + database GTT Users Meeting, 28.06.2017 Herzogenrath K. Hack 1, T. Jantzen 1, Elena Yazhenskhik 2, Michael Müller 2 1, 2 IEK2-FZ Jülich Contents of presentation A bit of history

More information

Activity Measurement of CaO SiO 2 AlO 1.5 MgO Slags Equilibrated with Molten Silicon Alloys

Activity Measurement of CaO SiO 2 AlO 1.5 MgO Slags Equilibrated with Molten Silicon Alloys ISIJ International, Vol. 40 (000), No. 6, pp. 561 566 Activity Measurement of CaO SiO AlO 1.5 MgO Slags Equilibrated with Molten Silicon Alloys Kousuke KUME, Kazuki MORITA 1), Takahiro MIKI ) and Nobuo

More information

Current Refractory Technology and Practices in the Steel Industry

Current Refractory Technology and Practices in the Steel Industry Current Refractory Technology and Practices in the Steel Industry April 26, 2017 Rakesh K. Dhaka 2016 Steel Production in Numbers United States 4 th largest producer of steel in the world Source: World

More information

The Study on Sulfur and Nickel Distribution Behavior of Nickel between Fe-Ni alloy and MgO-FeO-SiO 2 Slag System

The Study on Sulfur and Nickel Distribution Behavior of Nickel between Fe-Ni alloy and MgO-FeO-SiO 2 Slag System The Study on Sulfur and Nickel Distribution Behavior of Nickel between Fe-Ni alloy and MgO-FeO-SiO 2 Slag System Ki Deok Kim 1), Hyung Sub Eom 2), Eun Jin Jung 1), Wan Wook Huh 1), and Dong Joon Min 1)

More information

Sulphide Capacities of CaO Al 2 O 3 SiO 2 MgO MnO Slags in the Temperature Range K

Sulphide Capacities of CaO Al 2 O 3 SiO 2 MgO MnO Slags in the Temperature Range K ISIJ International, Vol. 49 (009), No., pp. 56 63 Sulphide Capacities of CaO Al O 3 SiO MgO MnO Slags in the Temperature Range 673 773 K Yoshinori TANIGUCHI,,) Nobuo SANO 3) and Seshadri SEETHARAMAN )

More information

REDUCING REFRACTORY COST USING NEW ASCC BRICKS FOR HOT IRON TRANSPORT

REDUCING REFRACTORY COST USING NEW ASCC BRICKS FOR HOT IRON TRANSPORT REDUCING REFRACTORY COST USING NEW ASCC BRICKS FOR HOT IRON TRANSPORT PENG, DEJIANG HE, ZHONGYANG YU, TERRY PUYANG REFRACTORY GROUP LTD. Drawings Outline Optimum Design Material Selection: Tar-Impregnated

More information

REFINING STEELS PRODUCED IN ELECTRIC ARC FURNACE

REFINING STEELS PRODUCED IN ELECTRIC ARC FURNACE U.P.B. Sci. Bull., Series B, Vol. 75, Iss. 2, 2013 ISSN 1454-2331 REFINING STEELS PRODUCED IN ELECTRIC ARC FURNACE Valentin MINCU 1, Nicolae CONSTANTIN 2 Characteristics and properties of cast and forged

More information

Mould fluxes for steelmaking - composition design and characterisation of properties. Research Institute, Stockholm

Mould fluxes for steelmaking - composition design and characterisation of properties. Research Institute, Stockholm Mould fluxes for steelmaking - composition design and characterisation of properties Carl-Åke Däcker KIMAB, Corrosion and Metals Research Institute, Stockholm The main functions for mould powder - and

More information

Melt corrosion of refractories in the nonferrous industry and the electric arc furnace: A thermochemical approach*

Melt corrosion of refractories in the nonferrous industry and the electric arc furnace: A thermochemical approach* Pure Appl. Chem., Vol. 83, No. 5, pp. 1093 1104, 2011. doi:10.1351/pac-con-10-10-05 2011 IUPAC, Publication date (Web): 4 April 2011 Melt corrosion of refractories in the nonferrous industry and the electric

More information

Dissolution Behavior of Mg from MgO into Molten Steel Deoxidized by Al

Dissolution Behavior of Mg from MgO into Molten Steel Deoxidized by Al , pp. 223 2238 Dissolution Behavior of Mg from MgO into Molten Steel Deoxidized by Al Akifumi HARADA, 1) Gaku MIYANO, 2) Nobuhiro MARUOKA, 3) Hiroyuki SHIBATA 3) and Shin-ya KITAMURA 3) * 1) Graduate Student,

More information

Arch. Metall. Mater. 62 (2017), 2,

Arch. Metall. Mater. 62 (2017), 2, Arch. Metall. Mater. 62 (2017), 2, 885-889 DOI: 10.1515/amm-2017-0130 J. FALKUS* # AN EVALUATION OF THE STABILITY OF MOULD FLUX PROPERTIES IN THE PROCESS OF CONTINUOUS STEEL CASTING This paper presents

More information

Using Automated Inclusion Analysis for Casting Process Improvements

Using Automated Inclusion Analysis for Casting Process Improvements Missouri University of Science and Technology Scholars' Mine Materials Science and Engineering Faculty Research & Creative Works Materials Science and Engineering 12-1-28 Using Automated Inclusion Analysis

More information

Dr. Joseph J Poveromo, Raw Materials & Ironmaking Global Consulting DR Pellet Quality & MENA Applications

Dr. Joseph J Poveromo, Raw Materials & Ironmaking Global Consulting DR Pellet Quality & MENA Applications Dr. Joseph J Poveromo, Raw Materials & Ironmaking Global Consulting joe.poveromo@rawmaterialsiron.com DR Pellet Quality & MENA Applications Chemistry Considerations direct reduction processes: chemical

More information

< > The Experience of ArcelorMittal Lázaro Cardenas Flat Carbon. By R. Lule 1), F.Lopez 2), J. Espinoza 3) R. Torres 4) & R.D.

< > The Experience of ArcelorMittal Lázaro Cardenas Flat Carbon. By R. Lule 1), F.Lopez 2), J. Espinoza 3) R. Torres 4) & R.D. 3 table of contents THE PRODUCTION OF STEELS APPLYING 100% DRI FOR NITROGEN REMOVAL The Experience of ArcelorMittal Lázaro Cardenas Flat Carbon By R. Lule 1), F.Lopez 2), J. Espinoza 3) R. Torres 4) &

More information

Hot Metal Desulfurization by CaO SiO 2 CaF 2 Na 2 O Slag Saturated with MgO

Hot Metal Desulfurization by CaO SiO 2 CaF 2 Na 2 O Slag Saturated with MgO ISIJ International, Vol. 50 (00), No., pp. 5 Hot Metal Desulfurization by CaO SiO CaF Na O Slag Saturated with MgO Moon Kyung CHO, ) Jin CHENG, ) Joo Hyun PARK ) and Dong Joon MIN ) ) Department of Metallurgical

More information

Table of Contents. Preface...

Table of Contents. Preface... Preface... xi Chapter 1. Metallurgical Thermochemistry... 1 1.1. Introduction... 1 1.2. Quantities characterizing the state of a system and its evolution... 3 1.2.1. The types of operations... 3 1.2.2.

More information

ANALYSIS OF HETEROGENEOUS NUCLEATION IN DUCTILE IRON

ANALYSIS OF HETEROGENEOUS NUCLEATION IN DUCTILE IRON ANALYSIS OF HETEROGENEOUS NUCLEATION IN DUCTILE IRON TMS 1, Simon N. Lekakh 2 1 TMS (The Minerals, Metals & Materials Society); 184 Thorn Hill Rd.; Warrendale, PA 15086-7514, USA 2 Missouri University

More information

1. Use the Ellingham Diagram (reproduced here as Figure 0.1) to answer the following.

1. Use the Ellingham Diagram (reproduced here as Figure 0.1) to answer the following. 315 Problems 1. Use the Ellingham Diagram (reproduced here as Figure 0.1) to answer the following. (a) Find the temperature and partial pressure of O 2 where Ni(s), Ni(l), and NiO(s) are in equilibrium.

More information

Why do we need new inclusion experimental techniques?

Why do we need new inclusion experimental techniques? University of Wollongong Research Online Faculty of Engineering - Papers (Archive) Faculty of Engineering and Information Sciences 2012 Why do we need new inclusion experimental techniques? Neslihan Dogan

More information

Sulfide Capacity of Molten CaO-SiO 2 -MnO-Al 2 O 3 -MgO Slags

Sulfide Capacity of Molten CaO-SiO 2 -MnO-Al 2 O 3 -MgO Slags Sulfide Capacity of Molten CaO-SiO -MnO-Al -MgO Slags Joo Hyun PARK ), * and Geun-Ho PARK,) ) School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749, Korea ) Steelmaking Technology

More information

The economics of electric arc furnace (EAF) technology

The economics of electric arc furnace (EAF) technology Foamy slag in EAF stainless steel production The benefits of foamy slag practice in EAF carbon steel production is well known and widely applied. However, until now, no suitable practice was available

More information

State of the thermodynamic database for the BOFdePhos project

State of the thermodynamic database for the BOFdePhos project State of the thermodynamic database for the BOFdePhos project K. Hack, T. Jantzen, GTT-Technologies, Herzogenrath GTT Users Meeting, July 2015, Herzogenrath Contents Old LD converter model database Necessary

More information

VALUE ENHANCEMENT THROUGH ENGINEERED ALUMINA PRODUCTS FOR MONOLITHIC AND BRICK APPLICATIONS

VALUE ENHANCEMENT THROUGH ENGINEERED ALUMINA PRODUCTS FOR MONOLITHIC AND BRICK APPLICATIONS VALUE ENHANCEMENT THROUGH ENGINEERED ALUMINA PRODUCTS FOR MONOLITHIC AND BRICK APPLICATIONS Andreas Buhr, Almatis GmbH, Germany Abstract The German steel institute VDEh organises international seminars

More information

Blast Furnace Regions Iron Making Furnace

Blast Furnace Regions Iron Making Furnace Blast Furnace Regions Iron Making Furnace The thickness of the lining depends on the furnace size STACK LINING The lining in stack should have good abrasion resistance and resistance to CO attack. In general,

More information

Alloy Recovery and Control in Steel Melting

Alloy Recovery and Control in Steel Melting Missouri University of Science and Technology Scholars' Mine Materials Science and Engineering Faculty Research & Creative Works Materials Science and Engineering 1-1-2005 Alloy Recovery and Control in

More information

Computer Supported Calculation and Evaluation of the Correct Composition of BOF Converter Slag

Computer Supported Calculation and Evaluation of the Correct Composition of BOF Converter Slag Computer Supported Calculation and Evaluation of the Correct Composition of BOF Converter Slag M. Bock, A.K. Louis, R. Müller, C. Oehler Abstract The paper presents the software package COAT Control Optimization

More information

Development of CaO-Al 2 O 3 Based Mold Flux System for High Aluminum TRIP Casting

Development of CaO-Al 2 O 3 Based Mold Flux System for High Aluminum TRIP Casting Development of CaO-Al 2 O 3 Based Mold Flux System for High Aluminum TRIP Casting Jung-Wook Cho 1, Kenneth E. Blazek 2, Michael J. Frazee 3, Hongbin Yin 2, Jeong Hyouk Park 4, Sang-Woon Moon 1 1:Steelmaking

More information

Fused Magnesia Trends. Global Outlook. Asım Bilge MagForum 2016, Vienna Kümaş Manyezit San. A.Ş.

Fused Magnesia Trends. Global Outlook. Asım Bilge MagForum 2016, Vienna Kümaş Manyezit San. A.Ş. Fused Magnesia Trends & Global Outlook Asım Bilge MagForum 2016, Vienna Kümaş Manyezit San. A.Ş. Contents Fused Magnesia Global FM Market, Demand and Prices Effects of Global Economy Issues Kümaş FM Production

More information

Atlantis, The Palm, Dubai, U.A.E December 10, 2014

Atlantis, The Palm, Dubai, U.A.E December 10, 2014 8A th Successful Middle East Model Iron and of Steel Cost Conference Reduction in the Melt Shop A successful model of cost reduction in the Middle East Iron and Steel Conference Atlantis, The Palm, Dubai,

More information

Materials engineering. Iron and steel making

Materials engineering. Iron and steel making Materials engineering Iron and steel making Metals: rarely exist in pure state mostly in ores Ore: Metallic and other compounds, mostly oxides Metallic content: Iron ores: 30-70% Fe Copper ores: 0.1-0.8

More information

STUDY ON SLAG RESISTANCE OF REFRACTORIES IN SUBMERGED ARC FURNACES MELTING FERRONICKEL

STUDY ON SLAG RESISTANCE OF REFRACTORIES IN SUBMERGED ARC FURNACES MELTING FERRONICKEL STUDY ON SLAG RESISTANCE OF REFRACTORIES IN SUBMERGED ARC FURNACES MELTING FERRONICKEL Dong HU 1 Pei-Xiao LIU 2 Shao-Jun CHU 1 1 School of Metallurgical and Ecological Engineering, University of Science

More information

FERRO ALLOY DESIGN, FERRO ALLOY SELECTION AND UTILISATION OPTIMIZATION WITH PARTICULAR FOCUS ON STAINLESS STEEL MATERIALS

FERRO ALLOY DESIGN, FERRO ALLOY SELECTION AND UTILISATION OPTIMIZATION WITH PARTICULAR FOCUS ON STAINLESS STEEL MATERIALS FERRO ALLOY DESIGN, FERRO ALLOY SELECTION AND UTILISATION OPTIMIZATION WITH PARTICULAR FOCUS ON STAINLESS STEEL MATERIALS C-J. Rick 1, M. Engholm 1 1 UVÅN HAGFORS TEKNOLOGI AB, Djursholmsvägen 30; 183

More information

Slag formation during high temperature interactions between refractories containing SiO 2 and iron melts with oxygen

Slag formation during high temperature interactions between refractories containing SiO 2 and iron melts with oxygen Slag formation during high temperature interactions between refractories containing SiO 2 and iron melts with oxygen E. Kapilashrami* 1, V. Sahajwalla 2 and S. Seetharaman 1 Refractory metal interactions

More information

Innovations in refining process technique Combined blowing vacuum converter with CO2

Innovations in refining process technique Combined blowing vacuum converter with CO2 Lutz Rose Jan Reichel Thomas Germershausen SMS Siemag AG Düsseldorf / Germany INTRODUCTION Innovations in refining process technique Combined blowing vacuum converter with CO2 The vacuum converter has

More information

Phase Equilibrium for the CaO SiO 2 FeO 5mass%P 2 O 5 5mass%Al 2 O 3 System for Dephosphorization of Hot Metal Pretreatment

Phase Equilibrium for the CaO SiO 2 FeO 5mass%P 2 O 5 5mass%Al 2 O 3 System for Dephosphorization of Hot Metal Pretreatment , pp. 1381 1385 Phase Equilibrium for the CaO SiO 2 FeO 5mass%P 2 O 5 5mass%Al 2 O 3 System for Dephosphorization of Hot Metal Pretreatment Xu GAO, 1) Hiroyuki MATSUURA, 1) * Masaki MIYATA 2) and Fumitaka

More information

Lecture 26 Degassing Practice

Lecture 26 Degassing Practice Lecture 26 Degassing Practice Contents: Degassing processes Ladle degassing Stream degassing Recirculation degassing Key words: degassing, hydrogen and nitrogen in steel, ladle degassing, recirculation

More information

Twinjection Technology Improves Hot Metal Desulphurisation at Corus Scunthorpe Works

Twinjection Technology Improves Hot Metal Desulphurisation at Corus Scunthorpe Works Twinjection Technology Improves Hot Metal Desulphurisation at Corus Scunthorpe Works Dr. Robert Robey, Process Metallurgist, Mark Whitehead, Manager - Technical Sales, SMS Mevac UK Limited, Winsford, UK;

More information

Influence of TiC on the Viscosity of CaO MgO Al 2 O 3 SiO 2 TiC Suspension System

Influence of TiC on the Viscosity of CaO MgO Al 2 O 3 SiO 2 TiC Suspension System , pp. 922 927 Influence of TiC on the Viscosity of CaO MgO Al 2 O 3 SiO 2 TiC Suspension System Guo-Hua ZHANG, 1,2) * Yu-Lan ZHEN 1,2) and Kuo-Chih CHOU 1,2) 1) State Key Laboratory of Advanced Metallurgy,

More information

X-ray Fluorescence Spectrometry X-ray Fluorescence Spectrometry (XRF) is a non-destructive, quantitative technique for determining chemical

X-ray Fluorescence Spectrometry X-ray Fluorescence Spectrometry (XRF) is a non-destructive, quantitative technique for determining chemical X-ray Fluorescence Spectrometry X-ray Fluorescence Spectrometry (XRF) is a non-destructive, quantitative technique for determining chemical composition. When a primary x-ray collides with an atom in the

More information

Chromium distribution between slag and non-carbon saturated metal phases under changing partial pressure of carbon monoxide

Chromium distribution between slag and non-carbon saturated metal phases under changing partial pressure of carbon monoxide Chromium distribution between slag and non-carbon saturated metal phases under changing partial pressure of carbon monoxide by X. Pan* and R.H. Eric* Synopsis Slag-metal equilibrium experiments were conducted

More information

EQUILIBRIUM IN PRODUCTION OF IDGH CARBON FERROMANGANESE

EQUILIBRIUM IN PRODUCTION OF IDGH CARBON FERROMANGANESE INFACON 7, Trondheim, Norway, June 1995 Eds.: Tuset, Tveit and Page Publishers: FFF, Trondheim, Norway 591 EQUILIBRIUM IN PRODUCTION OF IDGH CARBON FERROMANGANESE Sverre E. Olsen, Weizhong Ding-, Olga

More information

VŠB - Technical University of Ostrava Faculty of Metallurgy and Materials Engineering

VŠB - Technical University of Ostrava Faculty of Metallurgy and Materials Engineering VŠB - Technical University of Ostrava Faculty of Metallurgy and Materials Engineering Steel Casting Foundry (study supports) doc. Ing. Libor Čamek, Ph.D. Ostrava 2016 1. Basic parameters of electric arc

More information

GENARAL INTRODUCTION TO METALLURGY :Std: XI-CHEMISTRY

GENARAL INTRODUCTION TO METALLURGY :Std: XI-CHEMISTRY GENARAL INTRODUCTION TO METALLURGY :Std: XI-CHEMISTRY 1. What is matrix? The ore is generally associated with rock impurities like clay, sand etc. called gangue or matrix 2. What is mineral? The natural

More information

Liquidus Surface of FeO-Fe 2 O 3 -SiO 2 -CaO Slags at Constant CO 2 /CO Ratios

Liquidus Surface of FeO-Fe 2 O 3 -SiO 2 -CaO Slags at Constant CO 2 /CO Ratios Materials Transactions, Vol. 44, No. 10 (2003) pp. 2130 to 2135 #2003 The Japan Institute of Metals Liquidus Surface of FeO-Fe 2 O 3 -SiO 2 -CaO Slags at Constant CO 2 /CO Ratios Florian Kongoli 1 * and

More information

Parameters Affecting the Production of High Carbon Ferromanganese in Closed Submerged Arc Furnace

Parameters Affecting the Production of High Carbon Ferromanganese in Closed Submerged Arc Furnace jmmce.org Journal of Minerals & Materials Characterization & Engineering, Vol. 11, No.1, pp.1-2, 212 Printed in the USA. All rights reserved Parameters Affecting the Production of High Carbon Ferromanganese

More information

Advanced Master Course Process Technology of Metals

Advanced Master Course Process Technology of Metals Institut für Eisenhüttenkunde Rheinisch-Westfälische Technische Hochschule Aachen Advanced Master Course Process Technology of Metals (Part: Ferrous Process Metallurgy) Prof. Dr.-Ing. D. Senk 16-04-2010

More information

Thermochemistry and Kinetics of Iron Melt Treatment

Thermochemistry and Kinetics of Iron Melt Treatment Thermochemistry and Kinetics of Iron Melt Treatment Simon N. Lekakh *, David G. C. Robertson * and Carl R. Loper Jr. ** * University of Missouri Rolla, ** University of Wisconsin-Milwaukee, U.S.A. Abstract

More information

Magnesia-carbon refractories for the lining of gasification chambers: technical capabilities and limitations

Magnesia-carbon refractories for the lining of gasification chambers: technical capabilities and limitations Magnesia-carbon refractories for the lining of gasification chambers: technical capabilities and limitations M. Hampel*, P. Gehre, T. Schemmel, C.G. Aneziris 5th International Freiberg Conference on IGCC

More information

Final Technical Report. Project Title: Melting Efficiency Improvement. Award Number: DE-FC36-04GO Project Period: (January 2004 June 2012)

Final Technical Report. Project Title: Melting Efficiency Improvement. Award Number: DE-FC36-04GO Project Period: (January 2004 June 2012) Final Technical Report Project Title: Melting Efficiency Improvement Award Number: DE-FC36-04GO14230 Project Period: (January 2004 June 2012) Principal Investigator: Kent Peaslee, 573-341-4714, kpeaslee@mst.edu

More information

Use of DRI in EAF s. Gregory L. Dressel Dressel Technologies Pawleys Island, SC. Part II: Feeding and Melting of Direct Reduced Iron.

Use of DRI in EAF s. Gregory L. Dressel Dressel Technologies Pawleys Island, SC. Part II: Feeding and Melting of Direct Reduced Iron. Use of DRI in EAF s Gregory L. Dressel Dressel Technologies Pawleys Island, SC Part II: Feeding and Melting of Direct Reduced Iron Introduction Perhaps the most important consideration an operator gives

More information

Interfacial assessment of CaO-Al2O3-SiO2-MgO slags on MgAl2O4 spinel

Interfacial assessment of CaO-Al2O3-SiO2-MgO slags on MgAl2O4 spinel University of Wollongong Research Online Faculty of Engineering and Information Sciences - Papers: Part A Faculty of Engineering and Information Sciences 2013 Interfacial assessment of CaO-Al2O3-SiO2-MgO

More information

CHAPTER 10 PHASE DIAGRAMS PROBLEM SOLUTIONS

CHAPTER 10 PHASE DIAGRAMS PROBLEM SOLUTIONS CHAPTER 10 PHASE DIAGRAMS PROBLEM SOLUTIONS Solubility Limit 10.1 Consider the sugar water phase diagram of Figure 10.1. (a) How much sugar will dissolve in 1000 g of water at 80 C (176 F)? (b) If the

More information

STUDIES ON DIRECT REDUCED IRON MELTING IN INDUCTION FURNACE

STUDIES ON DIRECT REDUCED IRON MELTING IN INDUCTION FURNACE Trans. Indian Inst. Met. Vol.57, No. 5, October 2004, pp. 467-473 TP 1904 STUDIES ON DIRECT REDUCED IRON MELTING IN INDUCTION FURNACE S.K. Dutta, A.B. Lele and N.K. Pancholi Metallurgical Engg. Deptt.,

More information

Influence of Solid CaO and Liquid Slag on Hot Metal Desulfurization

Influence of Solid CaO and Liquid Slag on Hot Metal Desulfurization , pp. 10 17 Influence of Solid CaO and Liquid Slag on Hot Metal Desulfurization Koichi TAKAHASHI, 1) Keita UTAGAWA, 2) Hiroyuki SHIBATA, 3) Shin-ya KITAMURA, 3) Naoki KIKUCHI 4) and Yasushi KISHIMOTO 5)

More information

Manganese concentrate usage in steelmaking

Manganese concentrate usage in steelmaking IOP Conference Series: Materials Science and Engineering PAPER OPEN ACCESS Manganese concentrate usage in steelmaking To cite this article: O I Nokhrina and I D Rozhihina 2015 IOP Conf. Ser.: Mater. Sci.

More information

Effect of Chromium on Nitrogen Solubility in Liquid Fe Cr Alloys Containing 30 mass% Cr

Effect of Chromium on Nitrogen Solubility in Liquid Fe Cr Alloys Containing 30 mass% Cr ISIJ International, Vol. 49 (009), No., pp. 668 67 Effect of Chromium on Nitrogen Solubility in Liquid Fe Alloys Containing 30 mass% Wan-Yi KIM, ) Chang-Oh LEE, ) Chul-Wook YUN ) and Jong-Jin PAK ) ) Formerly

More information

Antônio Cezar Faria Vilela b

Antônio Cezar Faria Vilela b Materials Research. DOI: http://dx.doi.org/10.1590/1980-5373-mr-2017-0041 MgO Saturation Analisys of CaO -FeO-MgO- Slag System Rodolfo Arnaldo Montecinos de Almeida a *, Deisi Vieira a, Wagner Viana Bielefeldt

More information

EAF Technology and process

EAF Technology and process EAF Technology and process In the last 100 years,the EAF technology has evolved to meet the demands of higher productivity, improved quality of product and flexibility of metallic inputs. The product mix

More information

Effect of Oxygen Partial Pressure on Liquidus for the CaO SiO 2 FeO x System at K

Effect of Oxygen Partial Pressure on Liquidus for the CaO SiO 2 FeO x System at K , pp. 2040 2045 Effect of Oxygen Partial Pressure on Liquidus for the CaO SiO 2 FeO x System at 1 573 K Hisao KIMURA, Shuji ENDO 1), Kohei YAJIMA 2) and Fumitaka TSUKIHASHI 2) Institute of Industrial Science,

More information

Influence of hydrogen in weld joints

Influence of hydrogen in weld joints Influence of hydrogen in weld joints This chapter presents influence of hydrogen in weld joints on the soundness and performance of weld joints. Further, different types of fluxes, their stability and

More information

BENEFIT OF GAS PURGING IN BOF AND EAF WITH A FOCUS ON MATERIAL EFFICIENCY AND CO2 EMISSION REDUCTION.

BENEFIT OF GAS PURGING IN BOF AND EAF WITH A FOCUS ON MATERIAL EFFICIENCY AND CO2 EMISSION REDUCTION. 76 BENEFIT OF GAS PURGING IN BOF AND EAF WITH A FOCUS ON MATERIAL EFFICIENCY AND EMISSION REDUCTION. Thomas Kollmann, Marcus Kirschen, Christoph Jandl, Karl-Michael Zettl RHI AG, Vienna Abstract In highly

More information

Introduction to the phase diagram Uses and limitations of phase diagrams Classification of phase diagrams Construction of phase diagrams

Introduction to the phase diagram Uses and limitations of phase diagrams Classification of phase diagrams Construction of phase diagrams Prof. A.K.M.B. Rashid Department of MME BUET, Dhaka Concept of alloying Classification of alloys Introduction to the phase diagram Uses and limitations of phase diagrams Classification of phase diagrams

More information

Recent Developments in FactSage Thermochemical Software and Databases

Recent Developments in FactSage Thermochemical Software and Databases Recent Developments in FactSage Thermochemical Software and Databases Christopher. W. Bale,* E. Bélisle*, P. Chartrand*, S.A. Decterov*, G. Eriksson**, A. Gheribi*, K. Hack**, I.-H. Jung*, J. Melançon*,

More information

XRF S ROLE IN THE PRODUCTION OF MAGNESIUM METAL BY THE MAGNETHERMIC METHOD

XRF S ROLE IN THE PRODUCTION OF MAGNESIUM METAL BY THE MAGNETHERMIC METHOD Copyright(c)JCPDS-International Centre for Diffraction Data 2001,Advances in X-ray Analysis,Vol.44 398 XRF S ROLE IN THE PRODUCTION OF MAGNESIUM METAL BY THE MAGNETHERMIC METHOD H. L. Baker Northwest Alloys,

More information

The effect of magnesia and alumina crucible wear on the smelting characteristics of titaniferous magnetite

The effect of magnesia and alumina crucible wear on the smelting characteristics of titaniferous magnetite The effect of magnesia and alumina crucible wear on the smelting characteristics of titaniferous magnetite M.P. Maphutha, M. Ramaili, M.B. Sitefane, and X.C. Goso Mintek, Randburg Test work was conducted

More information

Improvement in Hot-Metal Dephosphorization

Improvement in Hot-Metal Dephosphorization Technical Report Improvement in Hot-Metal Dephosphorization UDC 669. 184. 244. 66 : 669. 046. 545. 2 Naoto SASAKI* Susumu MUKAWA Yuji OGAWA Ken-ichiro MIYAMOTO Abstract The converter-type hot metal pretreatment

More information

Reoxidation of Al Ti Containing Steels by CaO Al 2 O 3 MgO SiO 2 Slag

Reoxidation of Al Ti Containing Steels by CaO Al 2 O 3 MgO SiO 2 Slag , pp. 1669 1678 Reoxidation of Al Ti Containing Steels by CaO Al 2 O 3 MgO SiO 2 Slag Dong-Chul PARK, In-Ho JUNG, 1) Peter C. H. RHEE and Hae-Geon LEE Department of Materials Science & Engineering, Pohang

More information

Effect of CO Gas Concentration on Reduction Rate of Major Mineral Phase in Sintered Iron Ore

Effect of CO Gas Concentration on Reduction Rate of Major Mineral Phase in Sintered Iron Ore , pp. 570 575 Effect of CO Gas Concentration on Reduction Rate of Major Mineral Phase in Sintered Iron Ore Daisuke NOGUCHI, 1) * Ko-ichiro OHNO, 2) Takayuki MAEDA, 2) Kouki NISHIOKA 3) and Masakata SHIMIZU

More information

Phase Diagram Applications

Phase Diagram Applications Phase Diagrams Understanding the Basics F.C. Campbell, editor Copyright 2012 ASM International All rights reserved www.asminternational.org Chapter 14 Phase Diagram Applications Alloy phase diagrams are

More information

HOOK CRACK IN ELECTRIC RESISTANCE WELDED LINE PIPE STEEL

HOOK CRACK IN ELECTRIC RESISTANCE WELDED LINE PIPE STEEL HOOK CRACK IN ELECTRIC RESISTANCE WELDED LINE PIPE STEEL BY SIMA AMINORROAYA *, HOSSEIN EDRIS **, MEHRDAD FATAHI *** SYNOPSIS: One of the production methods for API line pipe steel is electric resistance

More information

Optimization Of Silica Fume, Fly Ash And Cement Mixes For High Performance Concrete

Optimization Of Silica Fume, Fly Ash And Cement Mixes For High Performance Concrete Optimization Of Silica Fume, Fly Ash And Cement Mixes For High Performance Concrete Richard A. Livingston 1 and Walairat Bumrongjaroen 2 1 Federal Highway Administration, Office of Infrastructure R&D,

More information

Sintering Behavior of Silica Filler Sands for Sliding Nozzle in a Ladle

Sintering Behavior of Silica Filler Sands for Sliding Nozzle in a Ladle , pp. 1823 1829 Sintering Behavior of Silica Filler Sands for Sliding Nozzle in a Ladle Yusuke KOBAYASHI, 1) Hidekazu TODOROKI, 1) * Fumiaki KIRIHARA, 1) Waki NISHIJIMA 2) and Hiroshi KOMATSUBARA 3) 1)

More information

Thermodynamics and Mechanism of Silicon Reduction by Carbon in a Crucible Reaction

Thermodynamics and Mechanism of Silicon Reduction by Carbon in a Crucible Reaction ORIENTAL JOURNAL OF CHEMISTRY An International Open Free Access, Peer Reviewed Research Journal www.orientjchem.org ISSN: 0970-020 X CODEN: OJCHEG 2016, Vol. 32, No. (6): Pg. 2929-2937 Thermodynamics and

More information

Melting of platinum group metal concentrates in South Africa

Melting of platinum group metal concentrates in South Africa Melting of platinum group metal concentrates in South Africa by J. Nell* History Synopsis An overview is given of the matte melting process used for the beneficiation of South African platinum group metal

More information

not to be republished NCERT GENERAL PRINCIPLES AND PROCE ISOLATION ISOL ELEMENTS Unit I. Multiple Choice Questions (Type-I)

not to be republished NCERT GENERAL PRINCIPLES AND PROCE ISOLATION ISOL ELEMENTS Unit I. Multiple Choice Questions (Type-I) I. Multiple Choice Questions (Type-I) 1. In the extraction of chlorine by electrolysis of brine. (i) (ii) (iii) (iv) oxidation of Cl ion to chlorine gas occurs. reduction of Cl ion to chlorine gas occurs.

More information

Lecture 12 Converter Steelmaking Practice & combined blowing. Key words: Top blown steelmaking, combined blowing, bottom stirring, hot metal refining

Lecture 12 Converter Steelmaking Practice & combined blowing. Key words: Top blown steelmaking, combined blowing, bottom stirring, hot metal refining Lecture 12 Converter Steelmaking Practice & combined blowing Contents: Refining of hot metal Composition and temperature during the blow Physico-chemical interactions Developments in Top blown steelmaking

More information

CHAPTER-6: SUMMARY AND CONCLUSIONS

CHAPTER-6: SUMMARY AND CONCLUSIONS CHAPTER-6: SUMMARY AND CONCLUSIONS 190 6. SUMMARY AND CONCLUSIONS 6.1 Summary of laboratory test work Based on the entire laboratory test work, findings are summarized as following; 6.1.1 Characterization

More information