National Engineering Research Center of Coal Preparation and Purification,China University of Mining and Technology
School of Chemical Engineering and Technology,China University of Mining and Technology
National Engineering Research Center of Green Recycling for Strategic Metal Resources,CAS Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences
School of Chemical Engineering,University of Chinese Academy of Sciences

电石渣循环回用制备高品质活性氧化钙,是实现其高效利用的有效途径之一,但电石渣复杂的组成和较高的硅含量制约了其制备活性氧化钙的产品品质。基于电石渣中硅类杂质分布规律和赋存形态,系统考察了浮选药剂对电石渣中硅的脱除效果,得出了适宜电石渣体系的脱硅药剂制度,研究了浮选前后电石渣中的元素组成变化和焙烧后氧化钙产品的性能变化,提出了电石渣浮选脱硅焙烧制备活性氧化钙的工艺路线。结果表明:电石渣中主要成分为氢氧化钙,含有部分二氧化硅和铝硅酸盐等硅类杂质,且颗粒分布较均匀,主要集中在低粒级分布。通过400g/t六偏磷酸钠和125g/t十二胺结合的一次反浮选脱硅试验,电石渣中硅类杂质得到有效分离,浮选后的电石渣精矿中硅质量分数由3.14%降至2.85%,且钙回收率达87.9%;浮选分离硅类杂质后的电石渣经900℃焙烧后可完全转化为氧化钙,制备的氧化钙产品中氧化钙质量分数为94.46%,抗压强度由3.17MPa提升至3.87MPa,冶金活性由341.6mL提升至385.5mL,产品性能有所提升。上述研究可为电石渣循环回用提供参考。

effective ways to achieve its efficient use, but the complex composition and high silicon content of calcium carbide slag restrict the productquality of the preparation of activated calcium oxide. Based on the distribution law and occurrence form of silica impurities in calcium carbide slag, the effect of flotation agents on the removal of silicon in calcium carbide slag were systematically investigated, a suitable desilication reagent for calcium carbide slag was obtained, the changes in elemental composition of calcium carbide slag and the changes in theproperties of active calcium oxide products after roasting before and after flotation were studied, and a process route for the preparationof calcium oxide by flotation desilication coupled with roasting of calcium carbide slag was put forward. The results indicate that calciumhydroxide is the main component of calcium carbide slag, which also contains some silicon impurities such as silica and aluminosilicate.Through a reverse flotation desilication test combined with sodium hexametaphosphate of 400 g/ t and dodecylamine of 125 g/ t, the silica mass fraction of calcium carbide slag is reduced from 3.14% to 2.85%, and the calcium recovery rate reaches 87.9%. The calcium carbide slag after flotation separation of silica impurities could be completely converted into calcium oxide after roasting at 900 ℃ , andthe calcium oxide mass fraction in the product is 94.46%, the compressive strength is increased from 3.17 MPa to 3.87 MPa, and the metallurgical activity is increased from 341.6 mL to 385.5 mL, and the product performance is improved. The above research can provide reference for the recycling of calcium carbide slag.

国家重点研发计划资助项目(2020YFC1908805);中国科学院绿色过程制造创新研究院自主部署资助项目(IAGM-2019-A09)

张凯旋,朱干宇,李会泉,等.电石渣浮选脱硅制备高品质活性氧化钙工艺[J].洁净煤技术,2024,30(7):39-46.

ZHANG Kaixuan,ZHU Ganyu,LI Huiquan,et al.Process of preparing high quality activated calcium oxide by flotation desiliconisation of calcium carbide slag[J].Clean Coal Technology,2024,30(7):39-46.