《厦门大学学报（自然科学版）》

采用Si-Cu合金精炼与CaO-SiO2-CaCl2造渣精炼相结合的方法对冶金级硅进行精炼,通过多种分析方法考察了合金造渣过程、渣剂添加剂和合金成分对金属杂质Fe、Al和Ca去除效果的影响.结果表明,提高Si-Cu合金中Cu的质量分数可以有效增加Cu3Si相在Si中的含量,造渣精炼过程会影响Si-Cu合金的相转变,造渣后金属杂质Fe和Ca聚集在Si-Cu合金的Cu3Si相中.在渣剂中添加CaCl2助溶剂可降低渣剂黏度以促进传质过程,从而有效提高金属杂质Fe、Al和Ca的去除率.此外,随着Si-Cu合金中Cu质量分数的增加,造渣后合金相中Cu的析出现象明显,Fe的去除率上升,Ca的去除率下降,而Al的去除率不变.当Si-30%Cu合金与CaO-SiO2-CaCl2(质量比9:9:2)渣剂进行精炼后,Fe、Al和Ca的去除率分别为68%,94%和86%.

A combined process of Si-Cu alloy refining and CaO-SiO2-CaCl2 slag refining was used to remove metallic impurities,Fe,Al and Ca,from metallurgical grade silicon(MG-Si).Effects of refining procedure,slag addition,and alloy composition on the removal efficiency were investigated using several methods.It was found that the content of the Cu3Si phase in the Cu-alloyed MG-Si increased when the mass fraction of Cu increased.The slag refining would affect the phase transformation of the Si-Cu alloy,and impurities,Fe and Ca,were found to concentrate in the Cu3Si phase after slag refining.The addition of CaCl2 facilitated the mass transfer process by decreasing the viscosity of the slag,thus enhancing the removal efficiency of impurities,Fe,Al and Ca.With themass fraction of Cu increasing,more Cu was precipitated after slag refining,the removal efficiency of Fe and Ca increased and reduced,respectively,while that of Al was unchanged.When Si-30%Cu alloy was refined with CaO-SiO2-CaCl2(9:9:2, by mass)slag,the removal efficiencies of Fe,Al and Ca were 68%,94%,and 86%,respectively.

引言
1 实验
2 结果与讨论
3 结论

图1 Si-Cu合金相图及制备的样品照片<br/>Fig.1 Phase diagram of Si-Cu alloy and photos of the prepared Si-Cu alloys

图1 Si-Cu合金相图及制备的样品照片
Fig.1 Phase diagram of Si-Cu alloy and photos of the prepared Si-Cu alloys

图2 Si-Cu合金的XRD谱图<br/>Fig.2 XRD patterns of Si-Cu alloys

图2 Si-Cu合金的XRD谱图
Fig.2 XRD patterns of Si-Cu alloys

图3 Si-50%Cu合金颗粒的断面SEM图(a)及对应的EDS谱图(b和c)<br/>Fig.3 SEM image of cross-section of a Si-50%Cu alloy powder(a)and the corresponding EDS spectra(b and c)

图3 Si-50%Cu合金颗粒的断面SEM图(a)及对应的EDS谱图(b和c)
Fig.3 SEM image of cross-section of a Si-50%Cu alloy powder(a)and the corresponding EDS spectra(b and c)

图4 Si-50%Cu合金(a)与CaO-SiO2渣剂精炼前(a)后(b)的TG-DSC曲线<br/>Fig.4 TG-DSC curves of Si-50%Cu alloy before(a)and after(b)CaO-SiO2 slag refining

图4 Si-50%Cu合金(a)与CaO-SiO2渣剂精炼前(a)后(b)的TG-DSC曲线
Fig.4 TG-DSC curves of Si-50%Cu alloy before(a)and after(b)CaO-SiO2 slag refining

图5 Si-50%Cu和CaO-SiO2造渣后合金(a)和渣剂(b)中合金相的SEM-EDS谱图<br/>Fig.5 SEM-EDS patterns of the Si-50%Cu alloy(a)and CaO-SiO2 slag(b)after slag refining

图5 Si-50%Cu和CaO-SiO2造渣后合金(a)和渣剂(b)中合金相的SEM-EDS谱图
Fig.5 SEM-EDS patterns of the Si-50%Cu alloy(a)and CaO-SiO2 slag(b)after slag refining

图6 Si-50%Cu和CaO-SiO2-CaCl2造渣后合金(a)和渣剂(b)表面的SEM图<br/>Fig.6 SEM images of surfaces of Si-50%Cu alloy(a)and CaO-SiO2-CaCl2 slag(b)after slag refining

图6 Si-50%Cu和CaO-SiO2-CaCl2造渣后合金(a)和渣剂(b)表面的SEM图
Fig.6 SEM images of surfaces of Si-50%Cu alloy(a)and CaO-SiO2-CaCl2 slag(b)after slag refining

表1 Si-50%Cu和CaO-SiO2-CaCl2造渣后两相的EDS分析<br/>Tab.1 EDS analysis on the Si-50%Cu andCaO-SiO2-CaCl2 phases after slag refining

表1 Si-50%Cu和CaO-SiO2-CaCl2造渣后两相的EDS分析
Tab.1 EDS analysis on the Si-50%Cu andCaO-SiO2-CaCl2 phases after slag refining

图7 Si-50%Cu合金造渣并酸洗后杂质Fe、Al和Ca的去除率<br/>Fig.7 Removal efficiencies of Fe, Al, and Ca from Si-50%Cu alloy after slag refining and acid leaching

图7 Si-50%Cu合金造渣并酸洗后杂质Fe、Al和Ca的去除率
Fig.7 Removal efficiencies of Fe, Al, and Ca from Si-50%Cu alloy after slag refining and acid leaching

图8 Si-30% Cu(a,b)、Si-50% Cu(c,d)、Si-70% Cu(e,f)合金分别与CaO-SiO2-CaCl2造渣前(a,c,e)后(b,d,f)的SEM图<br/>Fig.8 SEM images of Si-30%Cu(a,b), Si-50%Cu(c,d),Si-70%Cu(e,f)alloys before(a,c,e)and after(b,d,f)CaO-SiO2-CaCl2 slag refining

图8 Si-30% Cu(a,b)、Si-50% Cu(c,d)、Si-70% Cu(e,f)合金分别与CaO-SiO2-CaCl2造渣前(a,c,e)后(b,d,f)的SEM图
Fig.8 SEM images of Si-30%Cu(a,b), Si-50%Cu(c,d),Si-70%Cu(e,f)alloys before(a,c,e)and after(b,d,f)CaO-SiO2-CaCl2 slag refining