Abstract: In order to improve the comprehensive utilization rate of calcium carbide slag and solve the separation problem of impurities, this work focuses on the impurity composition and occurrence form of calcium carbide slag. Cyclone separation process was used to separate the impurities from calcium carbide slag efficiently through a physical short range. The composition and occurrence form of calcium carbide slag were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), and chemical analysis. Finally, the properties of activated calcium oxide products prepared from raw slag, fine slag, and coarse slag were compared. The results showed that the cyclone separation can effectively separate the coarse particles and ferrosilicon components in the calcium carbide slag. The content of particles larger than 106 μm in the coarse slag was 35.21wt%, and the amount were only 0.40wt% and 0.11wt% in the raw slag and fine slag, respectively. The iron enrichment phenomenon in the coarse slag was remarkable, and the content increased from 0.25wt% to 1.14wt%. The content of acid insoluble matter in the fine slag was significantly reduced. The occurrence formed of impurities in calcium carbide slag were not changed during cyclone separation process. Element of carbon mainly existed in the form of simple substance and carbonate, aluminum and silicon mostly existed in the form of aluminosilicate, and sulfur mainly existed in the form of sulfate, sulfide, and mercaptan. The compressive strength of calcium oxide products prepared with fine slag as raw material can reach 5.1 MPa, which was about 50% higher than that of raw slag and coarse slag.

Key words: dry process carbide slag, separation, impurity occurrence law, CaO, chemical analysis

摘要： 电石渣中Ca(OH)2含量达到了80%以上，针对电石渣中包含的大颗粒杂质影响其资源化利用的问题，采用了XRD, XRF, XPS, FTIR和化学分析等方法对杂质组分进行了系统分析，采用短程气固高效分离工艺对电石渣进行旋风分离，研究了旋风分离过程对杂质的分离效果和产品应用的影响。结果表明，电石渣中的碳主要以碳单质和碳酸盐形式存在，铝硅多以铝硅酸盐形式存在，硫主要以硫酸盐、硫化物和硫醇的形式存在；旋风分离后电石渣中粗颗粒显著富集，铁在粗渣中富集现象显著，铝硅和钙组分未富集，细渣中酸不溶物含量显著减少。利用电石渣制备活性氧化钙，旋风分离细渣所制备的氧化钙产品抗压强度达到了5.1 MPa，相对于原渣和旋风分离粗渣均提高了约50%；细渣制备的活性氧化钙产品中酸不溶物质量分数与原渣和粗渣相比也显著降低，为0.46wt%。本研究为电石渣的杂质分析及工业化应用提供了依据。

关键词: 干法电石渣, 分离, 杂质赋存规律, 氧化钙, 化学分析