(1. 江西理工大学 冶金与化学工程学院，赣州 341000；
2. 北京矿冶研究总院，北京 102206)
摘 要: 针对高硅钴白合金结构复杂、难以直接硫酸浸出问题，开展碱焙烧脱硅预处理研究以破坏稳定致密的硅铁合金结构。结果表明：经碱焙烧预处理后，钴白合金形貌发生明显改变。碱焙烧条件如下：温度600 ℃，NaOH用量为硅、铁反应所需理论量0.64倍。在上述条件下焙烧2 h后，所得渣经水洗，硅的脱除率达到66.57%；再经常压硫酸浸出，钴、铁浸出率均高达99%以上，而铜则完全保留在浸出渣中，实现了钴和铜分离，渣中的铜经第二段氧化浸出得以回收。进一步基于工艺矿物学分析，对碱焙烧脱硅预处理后钴白合金的常压浸出行为进行解析。
关键字: 钴白合金；碱焙烧；脱硅；预处理；常压浸出
（1. School of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology,
Ganzhou 341000, China;
2.Beijing General Research Institute of Mining and Metallurgy, Beijing 102206, China）
Abstract:The refractory high-silicon cobalt white alloy is difficult to be leached directly by sulfuric acid because of its complex structure. The pretreatment of alkali-roasting and desilication was carried out to destroy the stable ferro-silicon alloy structure. The results show that the alloy structure is changed greatly after alkali-roasting and 66.57% of silicon can be removed by water-washing after the alkali-roasting at 600 ℃ for 2 h. The optimum dosage of NaOH for alkali-roasting is 0.64 times of the theoretical amount for the reactions of silicon and iron with NaOH. After the desilication, more than 99% of cobalt and iron can be leached from the pretreated alloy while all of copper is kept in the residue during the atmospheric leaching, by which the ideal separation of cobalt from copper is achieved easily. The copper in the residue can be recovered by the second stage oxidative leaching. Based on the mineralogical analysis, the leaching behavior of pretreated alloy was further discussed.
Key words: cobalt white alloy; alkali roasting; desilication; pretreatment; atmospheric leaching
