Copper concentrate is a kind of ore with a certain grade of copper content, which can be extracted through smelting and can be turned into refined copper. The smelting of copper concentrate is accomplished mostly through oxidation-roasting method,and two-stage roasting method is widely used in copper concentrate smelting.
Through oxidation-roasting method,copper concentrate will be heated in the roaster until it has no moisture. In the meantime, air is injected into the roaster for oxidation of some components such as ferric oxide. The air flow rate and temperature range are designed in a way to ensure that most components are oxidized into oxides and converted into a form that can be easily melted and separated.
In one-stage saving roasting, usually copper concentrate is roasted directly in the roaster and the output of matte at the outlet is important. In oder to ensure the effective use of the heat in the roaster, it is necessary to control the feed speed of the furnace, the time of adding oxidant, and the particle size of the returned material.
In the two-stage roasting, the copper concentrate is roasted first in the roaster, and then the manufactured matte is sent to the second roaster for oxidation-roasting, after which the output of matte is taken. This method can effectively recover the copper lost by oxidation-roasting in the first roaster and improve the copper matte grade of the final matte produced.
The purpose of oxidation-roasting is to make the matte grade reach a certain target and the matte can be obtained after melting and flotation. Therefore, when choosing the method of oxidation-roasting, the quality of the matte produced must be considered. The oxidation-roasting process should be operated and controlled properly in order to get satisfactory matte quality as expected.
In general, in order to ensure a high matte grade and meet the requirements of the quality of matte, it is necessary to use a roasting method with a low oxygen content and a high roasting temperature in the oxidation-roasting process. In addition, the components and materials in the oxidation-roasting process should also be considered.
In summary, the oxidation-roasting of copper concentrate is an important step of the copper smelting process. By controlling the feed rate of the furnace, the time of adding oxidant, the particle size of the returned material and the oxygen content in the roaster, it is possible to obtain a high matte grade and meet the quality requirements of matte.
