长江中下游成矿带伴生钴资源现状及综合利用潜力评价

钴是中国极度短缺的关键矿产资源, 我国矿床中报道的钴资源量大部分以伴生形式产出, 因此估算伴生钴资源量及评价其综合利用前景十分必要。长江中下游成矿带铁矿床、铜矿床及硫铁矿床中普遍伴生钴, 但不同类型矿床中钴资源特征及差异、钴资源量及可利用性评价等研究尚未开展。目前大部分矿山伴生钴综合利用水平较低, 钴资源浪费严重。本文通过全面收集整理近年来长江中下游成矿带相关研究资料, 系统总结了成矿带不同类型矿床中钴的赋存状态, 阐明钴在各类矿床中的富集特征, 并估算了伴生钴资源量, 评价了伴生钴的可利用性。研究结果表明, 长江中下游成矿带铁矿床和硫铁矿床中主要载钴矿物为黄铁矿, 少量为磁黄铁矿、磁铁矿等; 铜矿床中载钴矿物以黄铁矿、黄铜矿为主, 少量为磁黄铁矿、斑铜矿等; 独立钴矿物在各类矿床中均有报道, 主要有辉砷钴矿、硫铜钴矿、铁硫砷钴矿、硫镍钴矿、辉钴矿、斜方砷钴矿等。钴在铁、铜和硫铁矿床中发生了不同程度富集, 其中矽卡岩型铁矿床中钴较为富集, 总体达到了伴生钴边界品位; 矽卡岩型铜矿床中的钴多数接近或达到伴生钴边界品位, 少数未达到伴生钴边界品位; 玢岩型铁矿床、斑岩型铜矿床、矽卡岩型和玢岩型硫铁矿床中钴的富集程度低, 普遍未达到伴生钴边界品位。成矿带伴生钴资源丰富, 具备形成中-大型富钴矿床的资源条件, 初步估算规模达到大型的矿床有3个(程潮、铁山、罗河), 规模达到中型的矿床有22个(龙桥、朱冲、白象山、金山店、安庆、武山、城门山、丰山洞、铜绿山、铜山口、大包庄、新桥、泥河、高村、梅山、和尚桥、姑山、沙溪、茶亭、姚家岭、冬瓜山、黄屯); 具有良好综合利用前景的伴生钴资源量约10.8万t, 具有一定综合利用前景的伴生钴资源量约4.6万t, 可作为未来潜在接替伴生钴资源量约12.5万t。成矿带主要矿床通过磁选、浮选可获得含钴>0.20%的硫精矿, 冶炼过程中可得到含钴达0.22%的转炉渣。对于含钴硫精矿或含钴转炉渣, 可通过浮选法、火法冶炼法、湿法分离法、萃取法和微生物浸出法等工艺实现钴的高效回收利用, 且回收率可达80%以上, 预期可以产生较好的经济效益。本文的研究方法对热液矿床中伴生钴资源量的评价具有重要的借鉴意义。

Evaluation on the current status and comprehensive utilization prospect of associated cobalt resources in the Middle-Lower Yangtze River Valley metallogenic belt

Cobalt is a critical mineral resource that is extremely scarce in China. Most of the reported cobalt resources in our country's deposits are produced in associated forms, so it is necessary to estimate the associated cobalt resources and evaluate their comprehensive utilization prospects. Cobalt is commonly associated with iron deposits, copper deposits, and pyrite deposits in the Middle and Lower Reaches of the Yangtze River metallogenic belt, but research on the characteristics and differences of cobalt resources in different types of deposits, the amount and availability of cobalt resources, etc., has not been conducted. Currently, the comprehensive utilization level of most mines' associated cobalt is relatively low, and cobalt resources are wasted severely. This article comprehensively collects and summarizes relevant research data on the Middle and Lower Reaches of the Yangtze River metallogenic belt in recent years, systematically summarizes the occurrence states of cobalt in different types of deposits, clarifies the enrichment characteristics of cobalt in various types of deposits, estimates the associated cobalt resources, and evaluates the availability of associated cobalt. The research results show that the main cobalt-bearing minerals in iron deposits and pyrite deposits in the metallogenic belt are pyrite, with a small amount of magnetite, pyrrhotite, etc. The main cobalt-bearing minerals in copper deposits are pyrite and chalcopyrite, with a small amount of magnetite, bornite, etc. Independent cobalt minerals have been reported in all types of deposits, mainly including skutterudite, cobaltite, loellingite, nickeliferous pyrite, cobaltian pyrite, arsenopyrite, etc. Cobalt has been enriched to varying degrees in iron, copper, and pyrite deposits, with the silicon-calcium type iron deposit having the highest cobalt enrichment, reaching the associated cobalt boundary grade overall; the cobalt in the silicon-calcium type copper deposit mostly approaches or reaches the associated cobalt boundary grade, with a few not reaching the associated cobalt boundary grade; the cobalt enrichment is low in the magnetite-type iron deposit, the porphyry-type copper deposit, and the silicon-calcium and porphyry-type pyrite deposits, and generally does not reach the associated cobalt boundary grade. The associated cobalt resources in the metallogenic belt are abundant and have the resource conditions for the formation of medium to large cobalt deposits. The preliminary estimated scale of large deposits is three (Chengchao, Tieshan, and Luohe), and the scale of medium deposits is twenty-two (Longqiao, Zhuchong, Baixiangshan, Jinshandian, Anqing, Wushan, Chengmenshan, Fengshandong, Tonglushan, Tongshankou, Dabaizhuang, Xinqiao, Nihe, Gaocun, Meishan, Heshangqiao, Gushan, Shaxi, Chating, Yaojialing, Dongguashan, and Huangtun). The associated cobalt resources with good comprehensive utilization prospects are approximately 108000 tons, and the associated cobalt resources with a certain comprehensive utilization prospect are approximately 46000 tons, which can be used as potential replacements for the associated cobalt resources of approximately 125000 tons in the future. The main deposits in the metallogenic belt can obtain sulfur concentrate with cobalt content greater than 0.20% through magnetic separation and flotation, and can obtain converter slag with cobalt content of up to 0.22% during the smelting process. For cobalt-containing sulfur concentrate or cobalt-containing converter slag, efficient recovery and utilization of cobalt can be achieved through processes such as flotation, pyrometallurgical smelting, wet separation, extraction, and microbial leaching, with a recovery rate of more than 80%, which is expected to generate good economic benefits. The research method in this article has important reference significance for the evaluation of associated cobalt resources in hydrothermal deposits.