Copper ore heap leaching is not only a long history and a large scale heap leach materials used, unlike the gold mine that is limited to oxide ores. Today, a large number of copper ore heaps are mixed minerals, mainly sulfide ore. From the perspective of the process of metallurgy, copper ore is generally classified into oxidized ore (such as black copper ore, chrysocolla, malachite, azurite, etc.), natural copper and secondary sulfide ore (such as copper ore, copper blue). Etc.), primary sulfide ore (such as chalcopyrite, sulfur- arsenic copper ore, beryllium copper, arsenic antimony ore, etc.). For heap leaching of copper oxide ore, only dilute sulfuric acid solution is used as the leaching solution; for heap leaching of natural copper and secondary sulphide ore, acidic leaching agent must be used under oxidizing conditions; for primary copper sulphide ore, Must be stronger oxidant or under strong oxidizing conditions. It should be noted that the time required for heap leaching of copper sulphide ore is quite long.
Historically been replaced with iron scrap heap leaching of leachate into the sponge copper Cu + (some companies are still in use); Today, many enterprises to adopt high iron salt as secondary copper sulfide heap leaching oxidant. Figure 1 is a potential-pH diagram of a copper-iron water system.
Figure 1 Cu, Fe-H 2 O system potential-pH diagram
The reaction formula and thermodynamic formula of each relevant line in the figure are as follows:
E=0.271-0.0591pH
Fe(OH) 2 +2H + +2e Fe(OH) 2 +2H 2 O
E=0.047-0.0591pH
From Figure 1, we can draw the following conclusions:
1. Lines 1 to 5 in Figure 1 constitute the potential-pH diagram of the Cu-H 2 O system, line 6 ~ The Fe-H 2 O system potential-pH diagram is constructed.
2. As seen from line 7 in the figure, Fe 3 + is a good oxidant for low-cost copper; as seen from line 10, Cu 2 + in the iron reduction solution is metallic copper.
Third, high-priced copper minerals, such as CuO, malachite, chrysocolla, etc., only need a very dilute acidic solution to leaching, the line 1 in the figure fully illustrates this point.
Fourth, comparing the lines 1 and 6 in the figure, it can be seen that the heap leaching copper ore, in the presence of oxidant, controls the pH of the leaching solution to achieve selective leaching of copper, while leaving iron in the ore heap.
2 Way Speaker,Coaxial Driver,Coaxial Speakers,Two Way Speaker
Ningbo Sonice Electroacoustic Science and Technology Co., Ltd. , https://www.secspk.com