National Engineering Research Center of Green Recycling for Strategic Metal Resources,CAS Key Laboratory of Green Process andEngineering,Institute of Process Engineering,Chinese Academy of Sciences
School of Chemical Engineering,University of Chinese Academy of Sciences
Huaneng Qinbei Power Generation Co.,Ltd.
Beijing Genyuan Environmental Protection Co.,Ltd.

电石渣→氧化钙→电石的循环利用,是实现电石渣钙质资源循环回用的有效途径,但由于电石渣组成复杂、提纯困难,目前仍难以实现大规模制备活性氧化钙循环利用。系统考察了电石渣焙烧过程的物相形貌变化,研究了不同粒径范围的电石渣成分组成差异,通过研究电石渣粒度特征及各粒级电石渣的焙烧特性,确定颗粒分级对电石渣制备活性氧化钙性能的影响。结果表明:电石渣中杂质集中在<45μm及>180μm颗粒中,酸不溶物、Fe、C等主要集中在150μm以上颗粒中;焙烧过程中,钙质组分在350~460℃、550~720℃两阶段逐渐转化为氧化钙,大部分碳质杂质颗粒能在800℃以下完成分解,影响制备活性氧化钙产品性能;活性氧化钙的抗压强度主要受颗粒粒度影响,活性度受粒径、成分共同影响,细颗粒会填补压制过程中颗粒间间隙,提高强度但阻碍水分渗透,粗颗粒中杂质过多难以分解且分解形成大型孔道,影响产品强度、活性,45~106μm较适宜制备活性氧化钙,活性度达411mL(以4mol/L标准盐酸计),抗压强度达2.46MPa。上述研究可为电石渣循环回用提供借鉴。

The recycling of calcium carbide slag-calcium oxide-calcium carbide is an effective way to realize the recycling of calcium carbide slag. However, due to the complex composition of calcium carbide slag and the difficulty of purification, large-scale preparation ofactive calcium oxide for recycling has not been achieved at present. In this paper, the changes in phase morphology during the calcinationprocess of calcium carbide slag were systematically investigated, and the composition differences of calcium carbide slag with different particle sizes were studied. By studying the particle size characteristics of calcium carbide slag and the roasting characteristics of calcium carbide slag of each particle size, the influence of particle size classification on the preparation performance of active calcium oxide from calcium carbide slag was clarified. The results show that the impurities in carbide slag are concentrated in the particles less than 45 μm andlarger than 180 μm, and the acid insoluble matter, Fe and C, etc. are mainly concentrated in the particles more than 150 μm. The calcium component is gradually transformed into calcium oxide in two stages ranging from 350 to 460 ℃ and 550 to 720 ℃ during the roastingprocess. Most of the carbonaceous impurity particles can decompose below 800 ℃ , which affects the performance of preparing activated calcium oxide products. The compressive strength of activated calcium oxide is mainly affected by particle size, and the metallurgicalactivity is jointly affected by particle size and composition. The fine particles will fill the intergranular gap during the pressing process, increasing the strength but hindering water penetration. Excessive impurities in coarse particles are difficult to decompose and form largepores, affecting the strength and activity of products. 45-106 μm is more suitable for the preparation of active calcium oxide, with an activity of 411 mL (4 mol/ L standard hydrochloric acid) and the compressive strength of 2.46 MPa. The above research can provide a goodreference and basis for carbide slag recycling.

国家重点研发计划资助项目(2020YFC1908805);华能集团沁北发电有限责任公司科技资助项目(HNKJ21-HF294);国家自然科学基金资助项目(22008247);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)

颜坤,朱干宇,李会泉,等.电石渣焙烧制备活性氧化钙及粒级影响规律[J].洁净煤技术,2023,29(11):133-139.

YAN Kun,ZHU Ganyu,LI Huiquan,et al.Preparation of active calcium oxide by calcining calcium carbide slag and theeffect of particle size[J].Clean Coal Technology,2023,29(11):133-139.