Overview of chemical treatment of refractory copper ore

Copper oxide minerals due to poor floatability, especially when the copper ore was difficult to float chrysocolla, cuprite and hydroxide form is less, manganese aluminum silicate impregnate copper or copper was bound forms Existence, copper mineral inlay particle size is very fine, combined with high copper content, when the content of slime is too much, it is difficult to obtain ideal technical and economic indicators by flotation treatment. At this time, the copper can be recovered by chemical beneficiation method.

The refractory copper ore treated by chemical beneficiation method is: often exists on the surface of many copper ore bodies, sometimes into a relatively developed oxidation zone; in some mines, large quantities of copper-bearing waste rock are stored in the early stage of large-scale mining (low grade) Copper ore); at the end of production, there will be copper-bearing residuals that cannot be produced; some flotation plants have old tailings with high copper content.

For the treatment of refractory copper mineral raw materials, the choice of chemical beneficiation method mainly depends on the phase composition of copper in the ore, surrounding rock characteristics and ore structure and other factors. If the gangue is an acidic rock and the copper mineral is a secondary copper mineral, the ore may be decomposed with dilute sulfuric acid; if the ore contains a considerable amount of copper sulfide mineral and natural copper in addition to the secondary copper mineral, The ore is decomposed by oxidizing acid leaching (hot pressure oxyacid leaching, high-priced salt leaching, bacterial leaching) or oxygen roasting-acid leaching. If the alkaline rocks predominantly gangue, secondary copper minerals and copper can be used as a general decomposition of ammonia leaching of copper metal when present; hot ammonia is decomposed if leaching also contains a considerable amount of copper sulphide minerals. If the copper in the ore is in the form of copper silicate or bound copper which is difficult to decompose, it can be treated by reduction roasting-ammonia leaching or segregation.

According to the characteristics of the immersion liquid obtained by decomposing copper ore and the requirements on the product form, the iron replacement method, the precipitation-flotation method, the direct electrowinning method-extraction-electrowinning method and the distillation-precipitation method can be used respectively from the immersion liquid. Copper is recovered and copper is generally recovered by flotation.

When leaching, depending on the ore characteristics and specific conditions, respectively, the percolation tank immersion, the earth immersion, the heap leaching and various agitation leaching processes may be employed. In-situ leaching and heap leaching are used to treat low-grade copper ore and waste rock. The leaching period is long and the leaching rate is low. The leaching tank and the leaching leaching are used to treat oxidized ore or mixed ore with copper grade higher than 0.5%. The cycle is short, the copper recovery rate is high, and the leaching rich liquid copper content is high, and the copper can be directly recovered by the electrowinning method.

Commonly used chemical treatment methods can be summarized as follows:

1. Leaching-displacement-electrowinning;

2. Leaching-extraction-electrowinning (LXE method) (including roasting-leaching-extraction-electrowinning);

3. Leaching-precipitation-flotation (LPE method);

Fourth, the isolation - flotation method.