含钴炉渣低温选择性还原捕集钴的技术基础

Non-availability of cobalt in smelting slag of nickel and copper is one of the main causes for low utilization of associated cobalt. The problems associate with existing technologies for the slag lies mainly in difficult in comprehensive utilization, high energy consumption, large initial costs and heavy environmental pollution. Here, a new way is put forward for efficient extraction of cobalt, using selective reduction and magnetic separation, in which cobalt is enriched in alloy under the interaction with iron and then is recovered by magnetic. . It is expected to develop the theoretical basis for the novel process of low temperature reduction and magnetic capture of cobalt, and provide theoretical support for the industrial application of this technology. The main scientific problems to be researched are: ①phase transformation rules of iron and cobalt contained minerals; ②reduction and diffusion mechanism of iron and cobalt, and aggregation behavior of crystal grain under the action of additives; ③dynamical controlling mechanism of selective reduction of iron and effective enrichment of cobalt at low temperature; ④effect of surface feature and interface property of new mineral structure on magnetic separation of iron and cobalt. This project research can also provide a way for cobalt secondary resources with the advantages of short process, efficient utilization and offer reliable technical guarantee for solving the shortage of cobalt resources.

铜镍熔炼渣中钴的未利用是造成铜镍矿伴生钴资源利用率低的主要原因之一。现有处理工艺存在钴回收困难、能耗高、投资大、环境污染严重等问题。为此，申请者提出了低温选择性还原-磁选捕集钴的新技术，在复合添加剂作用下使含钴炉渣中的钴与铁在低温下相互作用富集于合金相中并聚合长大，再经磁选回收。通过研究：①低温选择性还原过程中钴铁矿物的矿相转化规律；②添加剂作用下钴/铁的还原、迁移机制和晶粒的聚合、长大行为；③低温下铁的选择性还原和钴高效富集的动力学调控机制；④新生矿相的表面特性和界面性质对钴、铁磁选分离的影响等科学问题，构建含钴炉渣低温选择性还原－磁选捕集钴的理论基础，为该技术的工程化应用提供理论支撑。本课题研究将为我国钴二次资源的短流程、低成本高效利用和缓解我国钴资源短缺提供技术保证。

铜镍熔炼渣中钴的未利用是造成铜镍矿伴生钴资源利用率低的主要原因之一。现有处理工艺存在钴回收困难、能耗高、投资大、环境污染严重等问题。为此，本项目提出了低温选择性还原-磁选捕集钴的新技术，在添加剂作用下使含钴炉渣中的钴与铁在低温下相互作用富集于合金相中并聚合长大，再经磁选回收。通过XRD、SEM、EDS、XPS等分析手段详细研究了含钴炉渣中钴的赋存状态、钴矿物与铁矿物的嵌布特征；采用HSC、Factsage等热力学软件对添加剂作用下金属氧化物的还原过程进行了热力学分析；基于非等温过程的热分析研究，探明了不同添加剂对还原过程的作用效果；考察了还原过程中合金晶粒在矿物中的形貌、尺寸、分布以及添加剂对晶粒生长过程的影响；研究了钴氧化物低温选择性还原过程的动力学，明确了还原过程的限制步骤；考察了还原温度、添加剂种类、反应时间、还原剂用量、添加剂用量等对低温金属化还原过程中铁、钴回收率及钴富集率的影响，优化调控参数，实现了铁的选择性还原和钴的高效富集。通过上述研究，最终构建含钴炉渣低温选择性还原－磁选捕集钴的理论基础，为该技术的工程化应用提供理论支撑。本课题的研究将为我国钴二次资源的短流程、低成本高效利用和缓解我国钴资源短缺提供一定的技术保证。