Study On Process And Mechanism Of Lead Removal By Waste Copper And Copper

In recent years, with the rapid development of economy in our country, domestic demand for copper was to be rising. Because of a serious shortage of copper resources in our country, the gap between copper resources and copper production demands was bigger and bigger, the proportion of imports of copper resource is more and more yield. In order to make up for the problem of shortage of copper resources, and put forward the secondary copper resources namely miscellaneous copper scrap recycling, and the direct and indirect use of miscellaneous copper scrap has already described.The secondary copper resources as one of the important ways to make up for a lack of copper production of our country, saving energies, and environmental protection, but also it reduced the cost. Because the source of the secondary copper resources was extremely widespread, it had many kinds, and the composition was also complicated, resulted in copper scrap mixed with other impurities elements in copper, such As Fe, Al, Si, P, Zn, As, Sb, Ni, Pb, Sn, and so on. Although these elements in copper improved certain performances, but also could affect other properties of copper. For example, the element of lead can improve the machinability of copper, but lead can reduce the plasticity of copper alloy, its content is more than a certain amount, result in the embrittlement of copper alloy. Therefore, removal of impurities of the secondary copper resources becomes a problem urgently to be solved.This topic mainly solved the problem of secondary copper resources in addition to the lead. Elemental lead because of its good corrosion resistance, high ductility, wettability and the high density, low melting point, the high linear expansion coefficient and so on, therefore, it is widely used in industry and in life.But lead is as a kind of toxic substances as people all know. With the level of the continuous improvement of material life, people pay more and more attention to health issues. Therefore, the secondary copper resources in addition to lead is imminent.This topic mainly studied three kinds of agents: phosphoric acid, boric acid and silicate acid type, through the laboratory of the existing equipments, for optimization of the scrap copper fire refining process, and providing the theoretical foundation and development of new agent. With the help of the FACTSAGE software, the mechanism of lead of flux calculated, proved to the feasibility of in addition to lead to the reaction; at the same time, and useing FACTSAGE software for calculation of lead removal rate, in a certain range could be appropriate adjustment of flux composition. Under different temperature of the activity of lead was calculated, the results turned out that the higher the temperature, the higher the activity of lead, the larger the equilibrium constant, the more unfavorable to lead removal of reaction.Through the analysis of the three kinds of removal lead agent the phosphoric acid, boric acid and silicate type, found that removal lead agent of the phosphate type was the best one, its reaction time was the shortest. Removal lead agent of Boric acid type was also good, with the different composition of flux and the holding time, holding time for 30 min, the rate of removal lead was above 80%; removal lead agent of Silicate type was the worst, not only the reaction time is long, and the rate of removal lead was peaked at 50%.