Example of comprehensive recovery of copper and iron from copper tailings (Anqing Copper Mine)

Copper Ore Type anqing divided mineral composition diorite type copper, skarn copper, copper magnet type ore and iron ore skarn four, are all within the ore minerals. The main metal chalcopyrite mineral is chalcopyrite, magnetite, pyrrhotite, pyrite, after flotation, magnetic separation recovery of copper, iron, sulfur, there is still a small amount of non-dissociated into the monomer total Tailings; pyrrhotite contains iron and sulfur, which is second only to magnetite. When it is desulfurized by magnetic flotation, due to its strong magnetic properties, it inevitably entrains some fine-grained magnetite into the tailings. Beneficiation plant tailings total fractionated, + 20μm grain filling stage to the downhole sand magazine; -20 m grain size to the tailings. The chemical analysis of tailings is shown in Table 1.

Table 1 Chemical analysis results of tailings (%)

In order to comprehensively recover copper and iron resources from tailings, Anqing Copper Mine made full use of idle equipment and built a tailings comprehensive recovery copper and iron plant according to local conditions. Copper minerals are mainly concentrated in the coarse tailings, so the copper in the coarse tailings is mainly recovered. The tailings of the plant are carried with a certain amount of residual chemicals, so that the foam containing Cu and S is naturally enriched at the top of the sand storage bin. The copper-making factory is to make an industrial-type powerful inflatable flotation machine at the top of the sand storage bin. After the flotation coarse concentrate is re-ground, it is selected through a selection system of coarse and fine three-sweeping, and finally the copper grade is obtained. % qualified copper concentrate. Therefore, an investment of 300,000 yuan was spent in the filling station, and a 25t/d concentrator was built nearby.

The data in Table 1 also shows that iron is mainly concentrated in fine tailings, and laboratory studies have shown that the iron in fine tailings is mainly fine-grained magnetite and pyrrhotite. The iron ore plant is aimed at the fine-grained coltan and pyrrhotite in the fine-tailed sand. The CTB718 type weak magnetic separator is replaced by the main system. The investment is 100,000 yuan, and the fine tailings enter the thickener. The former position, making full use of the terrain height difference, established a tailings iron plant, and used a coarse and fine magnetic separation process to recover iron. In order to further recover the iron resources spilled from the plant, the various iron-bearing sewage, sludge, and selected tailings of the tailings copper-smelting plant in the mine were collected and integrated into the comprehensive iron-making plant. Finally, an iron concentrate with an iron grade of 63.00% can be obtained.

The production process of the copper and ironworks is shown in Figure 1. The annual output value of the two plants is 4.195 million yuan, and the estimated annual profit and tax is 4,214,500 yuan, which has achieved good economic and social benefits.

Figure 1 Production process of tailings comprehensive recovery copper and iron ore plant