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2 3 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes Zhongping Zhu, Tao Jiang, Guanghui Li, Yufeng Guo and Yongbin Yang School of Minerals Processing & Bioengineering, Central South University, Changsha, Hunan 4183, China 1. Introduction The thermodynamic of the chemical reactions among Al, CaO, SiO and Fe in the roasting processes was investigated in this chapter. The chemical reactions are classified into SiO -Al system, Fe -Al system, SiO -Fe system, CaO-Al system, SiO -CaO system, SiO -calcium aluminates system, CaO-Fe system, Al -calcium ferrites system and Al -CaO-SiO -Fe system. When the roasting temperature is over 11K, 3Al SiO is preferentially formed in SiO -Al system; FeO Al can be formed in Fe -Al system; ferric oxide and SiO could not generate iron silicate; 1CaO 7Al is preferentially formed in CaO-Al system when one mole Al reacts with CaO; CaO SiO is preferentially formed in SiO -CaO system; except for CaO Al and CaO Al, the other calcium aluminates can transform into calcium silicate by reacting with SiO in SiO -calcium aluminates system; CaO Fe is preferentially formed in CaO- Fe system; alumina is unable to form 3CaO Al with calcium ferrites(cao Fe and CaO Fe ), but able to form 1CaO 7Al with CaO Fe ; when CaO, Fe, Al,SiO coexist, they are more likely to form ternary compound CaO Al SiO and 4CaO Al Fe.. Binary compounds.1 Fe -Al -CaC system Fe and Al can all react with limestone during roasting to generate corresponding aluminates and ferrites. In Fe -Al -CaO system, the reaction Fe and Al with CaC coexist, and the reactions equations are as followed: Reactions A, J/mol B, J/K.mol Temperature, K CaC +Al =CaO Al +CO ~1 CaC +Fe =CaO Fe +CO ~1 Table 1. The G T of Fe -Al -CaC system GT ABT, J/mol; P partial pressure of CO in the air CO =3Pa, i.e., the

3 86 Thermodynamics Interaction Studies Solids, Liquids and Gases The relationships between Gibbs free energy ( G T ) and temperature (T) are as shown in figure /(KJ Mol -1 ) G/(KJ Mol -1 ) T G -5-1 CaC +Fe =CaO Fe +CO CaC +Al =CaO Al +CO T/K Fig. 1. Relationships between G T and temperature in Fe -Al -CaC system Figure 1 shows that, the Gibbs free energy of reactions on Fe and Al with CaC decreased with the rise of temperature in normal roasting process (due to decomposition of CaC over 1K, so the curve has no drawing above 1K), and the reactions all can automatically react to generate the corresponding calcium aluminate and calcium ferrite. The G T of reaction with Al is more negative than the G T of reaction with Fe at the same temperature. CaC has actually decomposed at 1473~1673K industrial roasting temperature, therefore, only CaO is taken into account on the following analysis.. SiO -Al system SiO mainly comes from the ore and coke ash in the roasting process. SiO reacts with Al to form aluminium silicates. The aluminium silicates mainly include Al SiO (AS ), Al SiO (AS,andalusite), AS(kyanite), AS(fibrolite), 3Al SiO (A 3 S ). Thermodynamic calculation indicates that, AS can not be formed from the reaction of Al and SiO under the roasting condition. The others equations are shown in table. Reactions A, J/mol B, J/K.mol Temperature, K Al =Al SiO kyanite ~1696 Al =Al SiO fibrolite ~1696 Al =Al SiO andalusite ~ ~1696 Al O SiO ( )3AlO3SiO Table. The G T of Al -SiO system GT ABT, J/mol The relationships of G T and temperature in Al -SiO system is shown in figure.

4 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes 87 G/(KJ Mol /(KJ Mol -1 ) -1 ) T G /Al + SiO = (1/)3Al SiO Al + SiO = Al SiO (kyanite) Al + SiO = Al SiO (fibrolite) Al + SiO = Al SiO (andalusite) T/K Fig.. Relationships of G T and temperature in Al -SiO system Figure shows that, the G T of kyanite is greater than zero at 1~17K, so the reaction cannot happen; the G T of andalusite and fibrolite alter little with temperature changes; the G T of A 3 S decreases with the rise of temperature. The thermodynamic order of forming aluminium silicates is A 3 S, AS(andalusite), AS(fibrolite) at 11~17K..3 Fe -Al system Al does not directly react with Fe, but Al may react with wustite (FeO) produced during roasting process to form FeO Al. No pure ferrous oxide (FeO) exists in the actual process. The ratio of oxygen atoms to iron atoms is more than one in wustite, which is generally expressed as Fe x O(x=.83~.95), whose crystal structure is absence type crystallology. For convenience, FeO is expressed as wustite in this thesis. Al may react with wustite(feo) to form FeO Al in the roasting process. The relationship of G T and temperature is shown in figure, and the chemical reaction of the equation is as followed: Al +FeO=FeO Al G T = T, J.mol ~165K (1) -1 T /(KJ Mol -1 ) G G/(KJ Mol -1 ) Al +FeO=FeO Al T/K Fig. 3. Relationship of G T and temperature in Fe -Al system

5 88 Thermodynamics Interaction Studies Solids, Liquids and Gases Figure 3 shows that, the G T is negative at 843~165K, reaction can happen and generate FeO Al ; the G T rises with the temperature, the higher temperature is, the lower thermodynamic reaction trends..4 SiO -Fe system SiO also does not directly react with Fe, but Al may react with wustite (FeO) to form FeO SiO (FS) and FeO SiO (F S). The relationships of G T and temperature is shown in figure 4, and the chemical reactions of the equations are shown in table 3. Reactions A, J/mol B, J/K.mol Temperature, K FeO =FeO SiO ~1413 FeO =FeO SiO ~1493 Table 3. The G T of SiO - Al system GT ABT, J/mol Figure 4 shows that, the G T of SiO - Al system are above zero at 847~15K, so all of the reactions can not happen to form ferrous silicates (FS and F S). 6 5 FeO + SiO = FeO SiO T/(KJ Mol -1 ) G G/(KJ Mol -1 ) FeO + SiO = FeO SiO T/K Fig. 4. Relationships of G T and temperature in SiO -Fe system.5 CaO-Al system Al can react with CaO to form calcium aluminates such as 3CaO Al (C 3 A), 1CaO 7Al (C 1 A 7 ), CaO Al (CA) and CaO Al (CA ). As regard as the calcium aluminates only C 1 A 7 can be totally soluble in soda solution, C 3 A and CA dissolve with a slow speed, and the other calcium aluminates such as CA are completely insoluble. Equations that Al reacted with CaO to form C 3 A, C 1 A 7, CA and CA are presented in table 4. Figure 5 shows that, the G T of reactions of Al with CaO decreases with the rise of temperature; all reactions automatically proceed to generate the corresponding calcium aluminates at normal roasting temperature (1473~1673K, same as follows); At the same

6 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes 89 roasting temperature, the thermodynamic order that one mole Al reacts with CaO to generate calcium aluminates such as C 1 A 7, C 3 A, CA, CA. Reactions A, J/mol B, J/K.mol Temperature, K 3CaO+ Al =3CaO Al ~ ~18 CaO+Al=( )1CaO 7AlO CaO+ Al =CaO Al ~ ~3 CaO+Al=( )CaO AlO 3 Table 4. The G T of Al -CaO system GT ABT, J/mol The relationships between G T and temperature (T) are shown in figure 5. /(KJ Mol -1 ) G,kJ.Mol /CaO+Al =(1/)CaO Al CaO+Al =CaO Al 1/7CaO+Al =(1/7)1CaO 7Al 3CaO+Al =3CaO Al T G T,K Fig. 5. Relationships between G T and temperature in Al -CaO system Reactions A, J/mol B, J/K.mol Temperature, K ~18 ( )3CaO Al+Al=( )1CaO 7AlO ~1878 ( )3CaO Al+Al=( )CaO AlO ~3 ( )3CaO Al+Al=( )CaO AlO ~1878 ( )1CaO 7Al+Al=( )CaO AlO ~3 ( )1CaO 7Al +Al=( )CaO AlO CaO Al + Al =CaO Al ~3 Table 5. The G T of Al -calcium aluminates system GT ABT, J/mol

7 83 Thermodynamics Interaction Studies Solids, Liquids and Gases When CaO is insufficient, redundant Al may promote the newly generated high calciumto-aluminum ratio (CaO to Al mole ratio) calcium aluminates to transform into lower calcium-to-aluminum ratio calcium aluminates. The reactions of the equations are presented in table 5: The relationships between G T of reactions of Al -calcium aluminates system and temperature (T) are shown in figure 6. CaO Al +Al =CaO Al - (1/7)1CaO 7Al +Al =(1/7)CaO Al (1/5)3CaO Al +Al =(3/5)CaO Al G T G,kJ.Mol /(KJ Mol -1 ) (1/5)1CaO 7Al +Al =(1/5)CaO Al (1/)3CaO Al +Al =(3/)CaO Al (4/3)3CaO Al +Al =(1/3)1CaO 7Al Fig. 6. Relationships between G T of reactions Al -calcium aluminates system and temperature T,K Figure 6 shows that, Gibbs free energy of the reaction of Al -calcium aluminates system are negative at 4~17K, and all the reactions automatically proceed to generate the corresponding low calcium-to-aluminum ratio calcium aluminates; Except for the reaction of Al -C 1 A 7, the G T of the rest reactions decreases with the rise of temperature and becomes more negative. Comparing figure 4 with figure 5, it can be found that Al reacts with CaO easily to generate C 1 A 7..6 SiO - CaO system SiO can react with CaO to form CaO SiO (CS), 3CaO SiO (C 3 S ), CaO SiO (C S) and 3CaO SiO (C 3 S) in roasting process. The reactions are shown in table 6, and the relationships between G of the reactions of SiO with CaO and temperature are shown in figure 7. Reactions A, J/mol B, J/K.mol Temperature, K CaO = CaO SiO (pseud-wollastonite) ~1817 CaO = CaO SiO (wollastonite) ~ ~17 CaO =( ) 3CaO SiO 3CaO = 3CaO SiO ~18 CaO = CaO SiO () ~43 CaO = CaO SiO () ~11 Table 6. The G T of SiO -CaO system( GT ABT, J/mol)

8 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes G T G/(KJ Mol /(KJ Mol -1 ) -1 ) CaO =CaO SiO (pseud-wollastonite) CaO =CaO SiO (wollastonite) (3/)CaO =(1/)3CaO SiO CaO =CaO SiO (ß) CaO =CaO SiO (γ) 3CaO =3CaO SiO T/K Fig. 7. Relationships between G T and temperature Figure7 shows that, SiO reacts with CaO to form -C S when temperature below 11K, but -C S comes into being when the temperature above 11K. At normal roasting temperature, the thermodynamic order of forming calcium silicate is C S, C 3 S, C 3 S, CS. Figure 5 ~ figure 7 show that, CaO reacts with SiO and Al firstly to form C S, and then C 1 A 7. Therefore, it is less likely to form aluminium silicates in roasting process..7 SiO - calcium aluminates system In the CaO-Al system, if there exists some SiO, the newly formed calcium aluminates are likely to react with SiO to transform to calcium silicates and Al because SiO is more acidity than that of Al. The reaction equations are presented in table 7, the relationships between G T and temperature are shown in figure 8. Figure 8 shows that, the G T of all the reactions increases with the temperature increases; the reaction (3CA =C 3 S+6Al ) can not happen when the roasting temperature is above 9K, i.e., the lowest calcium-to-aluminum ratio calcium aluminates cannot transform to the highest calcium-to-silicon ratio (CaO to SiO molecular ratio) calcium silicate; when the temperature is above 15K, the G T of reaction(3ca+ SiO =C 3 S+3Al ) is also more than zero; but the other calcium aluminates all can react with SiO to generate calcium silicates at 8~17K. The thermodynamic sequence of calcium aluminates reaction with SiO is firstly C 3 A, and then C 1 A 7, CA, CA.

9 83 Thermodynamics Interaction Studies Solids, Liquids and Gases Reactions A, J/mol B, J/K.mol Temperature, K (3)CaO Al =3CaO SiO +6Al ~18 (3)CaO Al =3CaO SiO +3Al ~18 ( 1 )1CaO 7Al O SiO 3CaO SiO 7 Al O ~18 ()CaO Al =CaO SiO +4Al ~171 ( 3 )CaO Al O SiO ( 1 )3CaO SiO 3Al O ~17 CaO Al = CaO SiO +Al ~1817 CaO Al =CaO SiO +Al ~1817 ( 3 )CaO Al O SiO ( 1 )3CaO SiO 3 Al O ~17 ()CaO Al =CaO SiO +Al ~171 ( 1 )1CaO 7Al O SiO CaO SiO 7 Al O ( 1 )1CaO 7Al O SiO ( 1 )3CaO SiO 7 Al O ~ ~17 ( 1 )1CaO 7Al O SiO CaO SiO 7 Al O ( 1 )3CaO Al O SiO CaO SiO 1 Al O ~ ~188 3CaO Al = 3CaO SiO +Al ~188 ( 1 )3CaO Al O SiO ( 1 )3CaO SiO 1 Al O ~17 ( )3CaO Al O SiO CaO SiO Al O ~171 Table 7. The G T of the reactions SiO with calcium aluminates( GT ABT, J/mol)

10 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes 833 /(KJ Mol G,kJ.Mol -1 ) -1 T G (3)CaO Al =3CaO SiO +6Al CaO Al =CaO SiO +Al (3)CaO Al =3CaO SiO +3Al (3/)CaO Al =(1/)3CaO SiO +(3/)Al (1/1)1CaO 7Al =CaO SiO +7/1Al (3/)CaO Al =(1/)3CaO SiO +3Al ()CaO Al =CaO SiO +Al (1/8)1CaO 7Al =(1/)3CaO SiO +7/8Al (1/6)1CaO 7Al =CaO SiO +7/6Al ()CaO Al =CaO SiO +4Al (1/4)1CaO 7Al =3CaO SiO +7/4Al CaO Al =CaO SiO +Al (1/3)3CaO Al =CaO SiO +1/3Al 3CaO Al =3CaO SiO +Al (1/)3CaO Al =(1/)3CaO SiO +1/Al (/3)3CaO Al =CaO SiO +/3Al Fig. 8. Relationships between G T and temperature in SiO -calcium aluminates system T,K.8 CaO- Fe system Fe can react with CaO to form CaO Fe (CF) and CaO Fe (C F). When Fe is used up, the newly formed C F can react with Fe to form CF. The reaction equations are shown in table 8, and the relationships between G and temperature are shown in figure 9. Figure 9 shows that, Fe reacts with CaO much easily to form C F; CF is not from the reaction of C F and Fe, but from the directly reaction of Fe with CaO. When Fe is excess, C F can react with Fe to form CF. Reactions A, J/mol B, J/K.mol Temperature, K CaO+Fe =CaO Fe ~1489 CaO+Fe =CaO Fe ~173 CaO Fe +Fe =()CaO Fe ~1489 Table 8. The G T of Fe -CaO system( GT ABT, J/mol)

11 834 Thermodynamics Interaction Studies Solids, Liquids and Gases -1 CaO Fe +Fe =CaO Fe T /(KJ Mol -1 ) G G,kJ.Mol CaO+Fe =CaO Fe CaO+Fe =CaO Fe Fig. 9. Relationships between G T and temperature in Fe -CaO system T,K.9 Al - calcium ferrites system Figure 1 shows that, the G T of the reaction of Al with CaC is more negative than that of Fe with CaC, therefore, the reaction of Fe with CaC occurs after the reaction of Al with CaC under the conditions of excess CaC. The new generated calcium ferrites are likely to transform into calcium aluminates when CaC is insufficient, the reactions are as followed: Reactions A, J/mol B, J/K.mol Temperature, K (3)CaO Fe + Al = 3CaO Al +3Fe ~ ( )CaO Fe O Al CaO Al O FeO 98~ ~1489 ( )CaO Fe O Al O ( )1CaO 7Al O FeO ~173 ( )CaO Fe O Al O ( )1CaO 7Al O FeO CaO Fe + Al =CaO Al +Fe ~ ~1489 ( )CaO Fe O Al O ( ) CaO Al O FeO ~173 ( )CaO Fe O Al O ( ) CaO Al O FeO ~173 ( )CaO Fe O Al O CaO Al O FeO3 Table 9. The G T of the reaction Al with calcium ferrites( GT ABT, J/mol) The relationships between G T and temperature (T) are shown in figure 1. Figure 1 shows that, Al cannot replace the Fe in calcium ferrites to generate C 3 A, and also cannot replace the Fe in CaO Fe (CF) to generate C 1 A 7, but it can replace the Fe in CaO Fe (C F) to generate C 1 A 7 when the temperature is above 1K, the higher temperature is, the more negative Gibbs free energy is; Al can react with CF and C F to

12 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes 835 form CA or CA, the higher temperature, more negative G T. Because Fe reacts with CaO more easily to generate C F (Fig.9), therefore, C 1 A 7 is the reaction product at normal roasting temperature(173~1673k) under the conditions that CaO is sufficent in batching and the ternary compounds are not considered. 6 (3)CaO Fe + Al = 3CaO Al +3Fe 4 G/(KJ Mol G T/(KJ Mol -1 ) (3/)CaO Fe + Al = 3CaO Al +3/Fe (6/7)CaO Fe + Al = (1/7)1CaO 7Al +6/7Fe (1/7)CaO Fe + Al = (1/7)1CaO 7Al +1/7Fe CaO Fe + Al = CaO Al +Fe - (1/)CaO Fe + Al = (1/)CaO Al +(1/)Fe (1/4)CaO Fe + Al = (1/)CaO Al +(1/4)Fe (1/)CaO Fe + Al = CaO Al +(1/)Fe Fig. 1. Relationship between G T and temperature in Al - calcium ferrites system T/K 3. Ternary compounds in Al -CaO-SiO -Fe system The ternary compounds formed by CaO, Al and SiO in roasting process are mainly CaO Al SiO (C AS), CaO Al SiO (CAS ), CaO Al SiO (CAS) and 3CaO Al 3SiO (C 3 AS 3 ). In addition, ternary compound 4CaO Al Fe (C 4 AF) is formed form CaO, Al and Fe. The equations are shown in table 1: Reactions A, J/mol B, J/K.mol Temperature, K CaO SiO + CaO Al =CaO Al SiO ~ ~186 Al O CaO SiO ( )CaO AlO3SiO Al + CaO + SiO =CaO Al SiO ~16 Al + CaO + SiO =CaO Al SiO ~ ~17 Al CaO SiO ( )3CaO AlO33SiO 3 3 4CaO +Al + Fe =4CaO Al Fe ~ Al + CaO + SiO =CaO Al SiO (cacoclasite) ~1863 Table 1. The G T of forming ternary compounds ( GT ABT, J/mol)

13 836 Thermodynamics Interaction Studies Solids, Liquids and Gases The relationships between G T and temperature (T) are shown in figure 11. Figure 11 shows that, except for C 3 AS 3 (Hessonite), all the G T of the reactions get more negative with the temperature increasing; the thermodynamic order of generating ternary compounds at sintering temperature of 1473K is: C AS(cacoclasite), C 4 AF, CAS, C 3 AS 3, C AS, CAS. C AS may also be formed by the reaction of CA and CS, the curve is presented in figure 11. Figure 11 shows that, the G T of reaction (Al +CaO ) is lower than that of reaction of CA and CS to generate C AS. So C AS does not form from the binary compounds CA and CS, but from the direct combination among Al, CaO, SiO. Qiusheng Zhou thinks that, C 4 AF is not formed by mutual reaction of calcium ferrites and sodium aluminates, but from the direct reaction of CaO, Al and Fe. Thermodynamic analysis of figure 1~figure11 shows that, reactions of Al, Fe, SiO and CaO are much easier to form C AS and C 4 AF, as shown in figure 1. CaO SiO + CaO Al =CaO Al SiO G/(KJ Mol G /(KJ Mol -1-1 ) T ) /CaO + 1/Al + SiO =(1/)CaO Al SiO (Anorthite) CaO + Al + SiO =CaO Al SiO CaO + Al + SiO =CaO Al SiO CaO + 1/3Al + SiO =(1/3)3CaO Al 3SiO (Hessonite) CaO + Al + SiO =CaO Al SiO (Gehlenite) 4CaO+Al +Fe =4CaO Al Fe Fig. 11. Relationships between G T of ternary compounds and temperature T/K Figure 1 shows that, in thermodynamics, C AS and C 4 AF are firstly formed when Al, Fe, SiO and CaO coexist, and then calcium silicates, calcium aluminates and calcium ferrites are generated. 4. Summary 1) When Al and Fe simultaneously react with CaO, calcium silicates are firstly formed, and then calcium ferrites. In thermodynamics, when one mole Al reacts with CaO, the sequence of generating calcium aluminates are 1CaO 7Al, 3CaO Al, CaO Al, CaO Al. When CaO is insufficient, redundant Al may promote the newly generated high calcium-to-aluminum ratio calcium aluminates to transform to lower calcium-toaluminum ratio calcium aluminates. Fe reacts with CaO easily to form CaO Fe, and CaO Fe is not from the reaction of CaO Fe and Fe but form the directly combination of Fe with CaO. Al cannot replace the Fe in calcium ferrites to generate 3CaO Al, and also cannot replace the Fe in CaO Fe to generate 1CaO 7Al, but can replace the Fe in CaO Fe to generate 1CaO 7Al when the temperature is above 1K; Al can react with calcium ferrites to form CaO Al or CaO Al.

14 Thermodynamics of Reactions Among Al, CaO, SiO and Fe During Roasting Processes 837-3/Al + SiO = (1/)3Al SiO Al + SiO = Al SiO (andalusite) 3CaO+Al =3CaO Al Al + SiO = Al SiO (kyanite) Al + SiO = Al SiO (fibrolite) CaO Fe +Fe =CaO Fe Al +FeO=FeO Al 1/CaO+Al =(1/)CaO Al CaO SiO + CaO Al =CaO Al SiO -4 CaO+Fe =CaO Fe CaO+Al =CaO Al 1/7CaO+Al =(1/7)1CaO 7Al CaO+Fe =CaO Fe 1/CaO + 1/Al + SiO =(1/)CaO Al SiO (Anorthite) -6 CaO + Al + SiO =CaO Al SiO G/(KJ Mol G -1 T -1 ) -8-1 CaO + Al + SiO =CaO Al SiO CaO =CaO SiO (pseud-wollastonite) CaO =CaO SiO (wollastonite) (3/)CaO =(1/)3CaO SiO CaO + 1/3Al + SiO =(1/3)3CaO Al 3SiO (Hessonite) -1 3CaO =3CaO SiO CaO =CaO SiO (ß) -14 CaO =CaO SiO (γ) 4CaO+Al +Fe =4CaO Al Fe -16 CaO + Al + SiO =CaO Al SiO (Gehlenite) Fig. 1. Relationships between G T and temperature in Al -CaO-SiO -Fe system ) One mole SiO reacts with Al much easily to generate 3Al SiO, Fe can not react with SiO in the roasting process in the air. Al can not directly react with Fe, but can react with wustite (FeO) to form FeO Al. 3) In thermodynamics, the sequence of one mole SiO reacts with CaO to form calcium silicates is CaO SiO, 3CaO SiO, 3CaO SiO and CaO SiO. Calcium aluminates can react with SiO to transform to calcium silicates and Al. CaO Al can not transform to 3CaO SiO when the roasting temperature is above 9K; when the temperature is above T/K

15 838 Thermodynamics Interaction Studies Solids, Liquids and Gases 15K, 3CaO Al can not transform to 3CaO SiO ; but the other calcium aluminates all can all react with SiO to generate calcium silicates at 8~17K. 4) Reactions among Al, Fe, SiO and CaO easily form CaO Al SiO and 4CaO Al Fe. CaO Al SiO does not form from the reaction of CaO Al and CaO SiO, but from the direct reaction among Al, CaO, SiO. And 4CaO Al Fe is also not formed via mutual reaction of calcium ferrites and sodium aluminates, but from the direct reaction of CaO, Al and Fe. In thermodynamics, when Al, Fe, SiO and CaO coexist, CaO Al SiO and 4CaO Al Fe are firstly formed, and then calcium silicates, calcium aluminates and calcium ferrites. 5. Symbols used Thermodynamic temperature: T, K Thermal unit: J Amount of substance: mole Standard Gibbs free energy: G T,J 6. References Li, B.; Xu, Y. & Choi, J. (1996). Applying Machine Learning Techniques, Proceedings of ASME 1 4th International Conference on Energy Sustainability, pp.14-17, ISBN , Phoenix, Arizona, USA, May 17-, 1 Rayi H. S. ; Kundu N.(1986). Thermal analysis studies on the initial stages of iron oxide reduction, Thermochimi, Acta. 11:17~118,1986 Coats A.W. ; Redferm J.P.(1964). Kinetic parameters from thermogravimetric data, Nature, 1:68,1964 LIU Gui-hua, LI Xiao-bin, PENG Zhi-hong, ZHOU Qiu-sheng(3). Behavior of calcium silicate in leaching process. Trans Nonferrous Met Soc China, January 13 16,3 Paul S. ; Mukherjee S.(199). Nonisothermal and isothermal reduction kinetics of iron ore agglomerates, Ironmaking and steelmaking, March 19~193, 199 ZHU Zhongping, JIANG Tao, LI Guanghui, HUANG Zhucheng(9). Thermodynamics of reaction of alumina during sintering process of high-iron gibbsite-type bauxite, The Chinese Journal of Nonferrous Metals, Dec 43~5, 9 ZHOU Qiusheng, QI Tiangui, PENG Zhihong, LIU Guihua, LI Xiaobin(7). Thermodynamics of reaction behavior of ferric oxide during sinter-preparing process, The Chinese Journal of Nonferrous Metals, Jun 974~978, 7 Barin I., Knacke O.(1997). Thermochemical properties of inorganic substances, Berlin:Supplement, 1997 Barin I., Knacke O.(1973). Thermochemical properties of inorganic substances, Berlin: Springer, 1973

16 Thermodynamics - Interaction Studies - Solids, Liquids and Gases Edited by Dr. Juan Carlos Moreno PirajÃ n ISBN Hard cover, 918 pages Publisher InTech Published online, November, 11 Published in print edition November, 11 Thermodynamics is one of the most exciting branches of physical chemistry which has greatly contributed to the modern science. Being concentrated on a wide range of applications of thermodynamics, this book gathers a series of contributions by the finest scientists in the world, gathered in an orderly manner. It can be used in post-graduate courses for students and as a reference book, as it is written in a language pleasing to the reader. It can also serve as a reference material for researchers to whom the thermodynamics is one of the area of interest. How to reference In order to correctly reference this scholarly work, feel free to copy and paste the following: Zhongping Zhu, Tao Jiang, Guanghui Li, Yufeng Guo and Yongbin Yang (11). Thermodynamics of Reactions Among AlO3, CaO, SiO and FeO3 During Roasting Processes, Thermodynamics - Interaction Studies - Solids, Liquids and Gases, Dr. Juan Carlos Moreno PirajÃ n (Ed.), ISBN: , InTech, Available from: InTech Europe University Campus STeP Ri Slavka Krautzeka 83/A 51 Rijeka, Croatia Phone: +385 (51) Fax: +385 (51) InTech China Unit 45, Office Block, Hotel Equatorial Shanghai No.65, Yan An Road (West), Shanghai, 4, China Phone: Fax:

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