Engineered Stone Made of Modified BOF Slag

Transcription

1 Engineered Stone Made of Modified BOF Slag Yao-Hung TSENG, Yu-Chen LEE, Kang-Shou LIAO Ceramic Materials Section New Materials Research & Development Dept. China Steel Corporation @mail.csc.com.tw

2 Content 1. Introduction 2. The Hot Stage BOF Slag Modification and Its Processing 3. The Property and Quality of the Modified BOF Slag 4. The Utilization of Modified BOF Slag Engineered Stone 5. Summary 2

3 Introduction O 2 ~1670 MgO + H 2 O Mg(OH) 2 CaO + H 2 O Ca(OH) 2 Volumetric expansion Poor quality for utilization 3

4 The Hot Stage BOF Slag Modification and Its Processing Principle: Methodology: 1.Molten slag 2.Blow oxygen into molten slag for getting heat generated from the oxidation of iron 3.Inject silica to react with f- CaO/MgO, so that transform them to silicates. Reaction: 4 FeO + O 2 2Fe 2 O 3 H=-531 kj/mol. 2 CaO(free) + SiO 2 2CaO SiO 2 2 CaO(free) + Fe 2 O 3 2CaO Fe 2 O 3 4.f-CaO reacts Fe 2 O 3 to form 2CaO Fe 2 O 3. f-cao/mgo is remelted completely. 4

5 The Hot Stage BOF Slag Modification and Its Processing Stand 2 Oxygen and additives injection system Topview Stand 1 Rod Lance 5

6 The Property and Quality of the Modified BOF Slag Before treatment after treatment f-cao XRD After treatment before treatment After modification Volumetric expansion <0.4% 6

7 The Property and Quality of the Modified BOF Slag Comparisons of the properties of natural aggregates, BOF slag and modified BOF slag Materials Natural aggregates specific gravity water absorption (%) loss of Los Angeles abrasion (%) loss of soundness (%) Mohs hardness Volumetric expansion (%) ~ ~0 BOF slag ~ % Modified BOF slag ~0 ~ <0.5% The utilization of modified BOF slag in engineering materials Asphalt Concrete pavement Pavement bricks Concrete products Railway Ballast 7

8 The Utilization of Modified BOF Slag Porous AC Freeway Grass Bricks Concrete Product (Tetrapods) Railway Ballast 8

9 The Utilization of Modified BOF Slag Engineered Stone High Value-added Products Engineered Stone Artificial marble / granite products: 30 (900 cm 2 ) 9

10 The Utilization of Modified BOF Slag Engineered Stone Production of Engineered Stone Made of Modified BOF slag and Resin Modified BOF slag grains Mixing Working time : 20 mins Mold shaking and vibrating in vacuum Resin + harden reagent (1%) mixture Cutting and polish 10

11 The Utilization of Modified BOF Slag Engineered Stone Size of raw materials (modified BOF slag) 5 cm 1 cm 5 cm 1 cm 1.7 mm 0.15 mm (100 mesh) 9 1 cm 11

12 The Utilization of Modified BOF Slag Engineered Stone Size 5 cm Porous surface 5 cm Larger modified BOF slag have more defects than smaller ones, which show apparent pores on the surface Choosing smaller grains 12

13 The Utilization of Modified BOF Slag Engineered Stone Grain size 1.7 mm Size distribution Wt. % Modified BOF slag /Engineered stone = 95.2% 10 13

14 The Utilization of Modified BOF Slag Engineered Stone Scale up : Making cm 2 engineered stone Input materials Mixing Vacuuming and shaking Shaking 改質人造石建材 Molding 14

15 The Utilization of Modified BOF Slag Engineered Stone The final product (area: cm 2 ) 1m 2 cm 15

16 The Utilization of Modified BOF Slag Engineered Stone Comparisons of commercial product and modified BOF slag engineered stone Commercial product Modified BOF slag engineered stone 16

17 The Utilization of Modified BOF Slag Engineered Stone Toxicity characteristic leaching procedure Test Materials/ Standard Modified BOF slag Modified BOF slag Engineered Stone Taiwan EPA Standard TCLP (mg/l) As Hg Ba Cd Cr Cu Pb Se Cr(VI) ph ND ND ND ND ND ND ND ND ND 12 ND ND ND ND ND ND ND ND ND 11.4 <5.0 <0.2 <100 <1.0 <5.0 <15.0 <5.0 <1.0 <

18 The Utilization of Modified BOF Slag Engineered Stone The cost and profit Products Engineered stone table Cost breakdown cost(euros/m 2 ) Crushing 7.14 Resin Molding Cutting and Polish Market price Net profit

19 The Utilization of Modified BOF Slag Engineered Stone Future work: colorful engineered stone 19

20 The Utilization of Modified BOF Slag Engineered Stone Surprising finding: High Far Infrared Emissivity at Room Temperature ε 2-22μm (25 ) = 0.91±0.3 Wine aging Fruit ripening 20

21 The Utilization of Modified BOF Slag Engineered Stone Future work: instead of crushing, using granulated tech Stopper Molten modified BOF slag Crucible Flow rate:20 kg/min Rotary cup (speed: 1500 rpm) 21

22 The Utilization of Modified BOF Slag Engineered Stone Granulated modified BOF slag product Wt. (%) Grain size(mm) % grains < 4.75mm

23 Summary The hot stage BOF slag modification process can produces high quality of volumetric stable aggregates with excellent physical properties. The engineered stone(with area up to cm 2 ) consisted of 95.2% modified BOF slag presents (particle size < 1.7mm) a compact structure with its water absorption(<0.3%), compressive strength (121.7 MPa), as well as flexural strength(41.6 MPa) are similar or even superior to commercial ones, which indicates modified BOF slag is a potential material for the production of high value-added products such as engineered stones. 23

24 Summary Toward the Development of High Value-added Products Taiji 24

25 Thanks for your attention. 25 Yao-Hung TSENG Research & Development Dept. China Steel Corporation

26 The Phase Diagram of BOF slag and the Modified BOF Slag BOF slag Modified BOF slag 26

27 Comparisons of the properties of artificial marble, artificial granite and modified BOF slag Materials Mohs hardness Compressive strength Artificial Marble 4 60 MPa Artificial granite MPa Modified BOF slag ~ MPa 27

28 Blind Drinking of Sorghum Wine Number of Participants :16 Original FIR at RT for 6h FIR at 60 for 6h Commercial Ceramics(6h) Spicy Scale Spicy Smooth Analytical data Aldehyde conc. (μm) Original FIR at RT for 123h FIR at 60 for 123h Commercial Ceramics (123h)