有色金属(冶炼部分)

针对铜钴矿湿法冶炼主流工艺低铜料液（CCD洗水）直接开路去钴回收系统，较高的游离酸未能有效利用，同时造成氧化水解除铁锰过程石灰消耗高等诸多问题，通过流程梳理，提出低铜料液逆向预浸技术构思。将低铜料液与磨矿底流预中和浸出，一方面消耗低铜料液的游离酸，有利于后续的水解除杂，另一方面对原矿底流进行预浸，降低后续浸出酸耗。通过系统的试验研究，得出在矿量比50%、预浸时间1 h等优化条件下，低铜料液余酸由初始8.50 g/L降至2.06 g/L，有效酸耗占比达64.81%。刚果（金）某4.5 Mt/a铜钴矿湿法冶炼厂产业化验证表明，在不影响铜钴回收效果的前提下，该技术每年可节省硫酸24.6 kt、石灰18.8 kt，酸耗降低约20%，降本增效成果显著。

Copper and cobalt, as key strategic resources, are widely applied in numerous fields such as aerospace, national defense and military industry, and new energy. In recent years, with the rapid development of the new energy vehicle industry, the demand for cobalt in power batteries has continued to rise. The Democratic Republic of the Congo(DRC) is one of the world's major cobalt producers, with reserves accounting for more than half of the global total. China has relatively scarce copper and cobalt resources. The dependence on imports for copper and cobalt is 70% and 90% respectively. Making full use of overseas resources and promoting the iterative upgrading of comprehensive recycling technologies are of great economic and strategic significance for ensuring the supply of copper and cobalt metal resources in China. A comprehensive utilization project for a low-grade copper-cobalt mine in DRC mainly processes typical oxidized minerals. After several years of operation, the system has been basically stable and has met the design standards, achieving good economic benefits. However, it is found that under the current process and control conditions, the acidity of the low-copper liquid(the liquid after countercurrent washing with thickner) is too high, which lead to problems such as low efficiency of subsequent copper extraction, large consumption of lime in the iron removal process, and waste of acid. In order to further enhance the value of resource recycling and achieve cost reduction and efficiency improvement for the enterprise, this study has reviewed the existing process flow and proposed a process improvement plan for the counter-current pre-leaching of lowcopper solution to consume the remaining acid. Laboratory experiments and industrial verification tests were carried out, and the changes in acid consumption and lime consumption indicators after the process improvement were compared and analyzed. The laboratory results show that the optimal pre-leaching conditions are a mineral ratio of 50%, one hour, and stirring speed of 500 r/min. During the pre-leaching process, the residual acid in the lowcopper solution can react with the copper-cobalt ore, and the concentration of the residual acid decreases from the initial 8.50 g/L to 2.06 g/L, the copper concentration increases from 5.15 g/L to 5.75 g/L, the total acid consumption, copper acid consumption and effective acid consumption are 6.44 g/L, 0.93 g/L and 5.51 g/L respectively, and the proportion of effective acid consumption is 64.81%. Based on the test results, the counter-current pre-leaching technology for low-copper solution is implemented. This enables the low-copper solution to undergo countercurrent pre-leaching with part of the bottom flow from the thickener, in order to fully utilize the residual acid. Industrial verification tests have shown that the pre-leaching process can effectively utilize the residual acid, saving 24 600 tons of sulfuric acid and 18 800 tons of lime annually, resulting in significant cost reduction and efficiency improvement.