采用选择性碳热还原方法高附加值利用转炉钢渣中有价组分，实验考察了还原温度和时间对转炉钢渣中主要有价元素Fe, P, Mn, Cr等的还原行为及析出多元铁合金(目标相)成分的影响，通过磨矿、磁选分离得到目标相和余渣，以目标相为主要原料合成锂离子电池正极材料掺杂型磷酸铁锂. 结果表明，产物0.1C下首次放电容量达159.58 mA?h/g，倍率循环性能良好；余渣主要成分为Ca(OH)2, 2CaO?SiO2和3CaO?SiO2，平均粒径约2.5 ?m且分布均匀，资源特性和利用价值明显提升.
A new method for respective and high value-added utilization of the valuable components in BOF steel slag was proposed. Using the selective carbothermic method, the reduction behavior of the valuable elements Fe, P, Mn, Cr etc in BOF steel slag and the composition of the ferroalloy (target phase) precipitated from the slag effected by reduction temperature and time were investigated. Target phase and residues were obtained from the reduced slag by milling and magnetic separation. The metals-doped LiFePO4/C, a cathode material of lithium ion battery was synthesized by using the target phase recovered from the slag as main raw material. The results showed that exhibiting first discharge capacity of 159.58 mA?h/g at 0.1C and excellent rate performance. The residue was fine powders with mean size of about 2.5 ?m and uniform size distribution, and its main phases include Ca(OH)2, 2CaO?SiO2 and 3CaO?SiO2, showing significantly improved resource characteristics and utilization value.
参考文献
1. Tsakiridis P E, Papadimitriou G D, Tsivilis S, et, al. Utilization of Steel Slag for Portland Cement Clinker Production [J]. Journal of Hazardous Materials, 2008, 152(2): 805-811.
2. Chand S, Paul B, Kumar M. Sustainable Approaches for LD Slag Waste Management in Steel Industries: A review [J]. Metallurgist, 2016, 60(1-2): 116-128.
3. Piatak N M, Parsons M B, Seal II R R. Characteristics and Environmental Aspects of Slag: A Review. Applied Geochemistry, 2015, 57: 236-266.
4. 张朝晖, 廖杰龙, 巨建涛, 等. 钢渣处理工艺与国内外钢渣利用技术[J]. 钢铁研究学报, 2013, 25(7): 1-4.
5. Liu Q, Liu J X, Qi L Q. Effects of Temperature and Carbonation Curing on the Mechanical Properties of Steel Slag-Cement Binding Materials [J]. Construction and Building Materials, 2016, 124: 999-1006.
6. Wang Q, Yan P Y, Feng J W. A Discussion on Improving Hydration Activity of Steel Slag by Altering Its Mineral Compositions [J]. Journal of Hazardous Materials, 2011, 186(2-3): 1070–1075.
7. Sorlini S, Sanzeni A, Rondi L. Reuse of Steel Slag in Bituminous Paving Mixtures [J]. Journal of Hazardous Materials, 2012, 209-210: 84 - 91.
8. Chaurand P, Rose J, Briois V, et, al. Environmental Impacts of Steel Slag Reused in Road Construction: A Crystallographic and Molecular (XANES) Approach [J]. Journal of Hazardous Materials, 2007, B139(3): 537-542.
9. 李光强, 张峰, 张力, 等. 高温碳热还原进行转炉渣资源化的研究[J]. 材料与冶金学报, 2003, 2(3): 167-172.
10. Morita K, Guo M, Oka N, et, al. Resurrection of the Iron and Phosphorus Resource in Steel-Making Slag [J]. Journal of Material Cycles and Waste Management, 2002, 4(2): 93-101.
11. Ye G Z, Burstr?m E, Kuhn M, et, al. Reduction of Steel-Making Slags for Recovery of Valuable Metals and Oxide Materials [J]. Scandinavian Journal of Metallurgy, 2003, 32(1): 7–14.
12. Jung S M, Do Y J, Choi J H. Reduction Behaviour of BOF Type Slags by Solid Carbon [J]. Steel Research International, 2006, 77(5): 305-311.
13. Jung S M, Do Y J. Reduction Behaviour of BOF Slags by Carbon in Iron [J]. Steel Research International, 2006, 77(5): 312-316.
14. Yuan H, Wang XY, Wu Q. Effects of Ni and Mn Doping on Physicochemical and Electrochemical Performances of LiFePO4/C [J]. Journal of Alloys and Compounds, 2016, 675: 187-194.
15. Naik A, Zhou J, Gao C, et, al. Impact of Incorporation of Chromium on Electrochemical Properties of LiFePO4/C for Li-ion Batteries [J]. Materials Science-Poland, 2015, 33(4): 742-750.
16. Loveridge M J, Lain M J, Johnson I D, et al. Towards High Capacity Li-ion Batteries Based on Silicon-Graphene Composite Anodes and Sub-micron V-doped LiFePO4 Cathodes [J]. Scientific reports, 2016, 6: 37787.
