The Lanping Low-grade Oxide Of Lead And Zinc Mining And Metallurgy New Technology

In this paper, based on lots of literatures, discuss the future development trends for the zinc production and expounded the importance of the further study of low-grade oxide ores. With the rapid development of the world economy, especially the high-speed operation of the China's economy, the demand for zinc metal increased every year. In 2005, the global outputs of refined zinc were 10.226 million tons. Meanwhile, china's outputs were more than 2.71 million tons, which were4.30% of the global capacity and the biggest one in the world. In 2006, the demand for zinc metal was continue to be increased in the rate of 4.26% all over the world. As the depletion of zinc concentrate resources and the increase in demand for zinc metal and the expansion of production capacity, the contradiction between supply and demand was aggravated. Therefore, the studies about extraction metals from low-grade oxide ores had been given more and more attention by researchers all over the world.The treatment technologies of low-grade zinc oxide ores were studied in detail in this paper. These technologies were sulphidization-ammonium method,sulphidization-xanthate flotation method,fatty acid flotation collectors and other flotation method of zinc oxide respectively.On the basis of the characters of the zinc oxide ores from Yunnan Lanping Jinding mine, which were rich in reserves but low in grade,complicated in properties and difficult in recycling, the effects of various minerals at different conditions are experimentally studied based on lots of published literatures and other previous works. On the experimental studies of the heavy-media separation,the limestone-type ores flotation,the sandstone-type ores flotation,the limestone-type and sandstone-type mixed ores direct flotation,the limestone-type and sandstone-type mixed ores pressure-treatment thermal-dissolved-sulfur, the most effective and promising study was the limestone-type and sandstone-type mixed ores pressure-thermally dissolved-sulfation process.The experimental studies of the limestone-type and sandstone-type mixed ores pressure-treatment thermal-dissolved-sulfur process which combined with smelting and beneficiation processes. Was innovative and novel. It was suitable to deal with low-grade ores from Yunnan Lanping Jinding mine. Meanwhile, it didn't need the procedure of milling and desliming. The optimum technological conditions were as follows:a temperature of about 180℃,a pressure of 3.0Mpa and a curing time of about three hours. Under these conditions, the curing efficiency was above 90% and the recovery ratio of zinc sulphide was over 80%. Furthermore, this method had advantages of a simple procedure and operation,without any harmful gas and solid waste in pretreatment procedure, which met the requirement of energy-saving,environment-friendly and recycling economy.The heavy-media separation process was only fit for limestone-type oxides. Though the calcium can be effectively removed, the zinc sulfuration concentrate except a small quantity of particles can't reach the grade of 22% by table gravity separation. It was shown that this process was not very good for treating the ores from Lanping Jinding mine and it can't satisfy the demands of production. Thereby, a further research of mining and metallurgy was needed to be done.It was difficult to vulcanize the oxides on the limestone-type ores flotation. The result indicated that it was necessary to rise in temperature and to add a great deal of curing agents such as sodium sulphide and auxiliary collectors such as zinc white, which had a long and complicated process and increased the production cost. The flotation of zinc sulphide was the first step then was the flotation of zinc oxide, and the procedure of desliming was needed, which was difficult to control in the real production.The result of the sandstone-type ores flotation was similar to that of limestone-type ores. It was necessary to rise in temperature and to add a great deal of curing agents such as sodium sulphide and auxiliary collectors such as zinc white, which had a long and complicated process and increased the production cost. The flotation of zinc sulphide was the first step then was the flotation of zinc oxide, and the procedure of desliming was needed, which was difficult to control in the real production. Therefore, a further research of mining and metallurgy was also need to be done.The result of limestone-type and sandstone-type mixed ores direct flotation indicated that various and vast chemicals was needed to achieve the advantageous aim, which would increase the production cost in the future. Although the lead sulphide,zinc sulphide and zinc oxide etc can be effectively recovered, it needed excessive chemicals and a long process, especially the desliming of oxide ores would produce large numbers of residue. It was also difficult to control in the real production. Hence, this process still had shortage to treat with the mixed ores. Adaptive technologies to fit the mixed ores were needed to be further investigated.Ores with different diameters were also researched in this paper. It was shown that the diameters of ores affected the flotation result. The percentage loss of zinc in the ores with much mud increased with the decrease of the ores diameters, which was not favorable for flotation.It was not only beneficial for the development of the corporation, but also an important contribution for the world to treat with the low-grade oxides. Meanwhile, it was of great significance for the comprehensive use of resources. It was necessary to continue to research the low-grade oxides and increase input funds.