Electroplating industry generate a lot of electroplating sludge containing heavy metals Cu, Ni, Zn, Cr, F , etc., since the plating process, the type, and the waste water treatment process and plating process varies, a very complex composition. The harm caused by electroplating sludge to the environment and human health has attracted great attention. The electroplating sludge contains a variety of metal components, and its grade is often higher than that of metal-rich ore. The complex nature is one of the recognized public hazards at home and abroad, but its It is also a cheap secondary renewable resource. At present, the purpose of harmless treatment is mainly achieved by solidification stabilization of sludge and its resource utilization. Curing/stabilizing is primarily the addition of some curing agent to cure the source of contamination. Recycling of electroplating sludge In recent years, research directions and resource utilization methods have been used. For example, recycling useful metals in electroplating sludge, composting agricultural or processing into industrial raw materials, while eliminating the hazard of electroplating sludge It can also obtain certain economic benefits, so the resource utilization of sludge and related technologies will become the research focus of heavy metal sludge treatment technology. China's electroplating factories are many, small and scattered, and production technology is backward. At present, the treatment of electroplating wastewater by chemical precipitation is the most simple and effective method. For most electroplating plants, the mud production rate is generally about 2.2×10 -3 . According to the different treatment methods of electroplating wastewater, the electroplating sludge can be divided into two types: mixed sludge and separated sludge: the former is sludge formed by mixing different kinds of electroplating wastewater for treatment; the latter is the different types of sludge electroplating wastewater treatment are formed, such as chromium-containing sludge, sludge containing copper, nickel-containing sludge, sludge containing zinc. Depending on the conditions of the plating wastewater treatment, electroplating sludge is divided into non-chromium-based and chromium-based sludge sludge two kinds: the former except chromium hydroxide still contains an outer iron, zinc, nickel, copper and other metals, the latter Containing no chromium, the main component is a hydroxide of metals such as iron, zinc, nickel and copper. However, in fact, most of the electroplating small enterprises' wastewater is treated with mixed sludge. At present, the treatment and resource utilization of electroplating sludge is also mainly based on mixed sludge. Copper leaching Leaching is a process in which a solvent selectively dissolves a target component in a solid waste, allowing the component to enter a solution to separate it from other components in the waste. After a certain pretreatment, the copper-containing electroplating sludge is leached with ammonia, sulfuric acid or biological method. The ammonia leaching selectivity is good, but the ammonia water has a pungent odor, and the sealing property of the leaching device is high, and when the concentration of NH 3 is more than 18%, the ammonia water volatilizes more, resulting in loss of ammonia water and deterioration of the operating environment. Sulfuric acid leaching reaction time is shorter and the efficiency is higher, but sulfuric acid has strong corrosiveness and high requirements for reactor anticorrosion. Biolead leaching costs are low, but the reaction time is very long and generally takes more than 20 days, thus requiring a larger reactor volume. Which leaching method to take is determined by the sludge. 1 ammonia leaching method Ammonia leaching is commonly used for the leaching of wastes containing metals such as copper and their oxides. Since copper can form a stable soluble complex with ammonia, it expands the stable region of copper ions in the leachate, reduces the reduction potential of copper, and makes it easier to transfer into the infusion. The main reactions of ammonia leaching copper and its minerals are: 2 acid leaching direct method The acid leaching method mainly uses a common acid such as sulfuric acid to leach copper-containing sludge and copper ore, and leaches the metal such as copper into the solution in an ion form. The principle is mainly to use acid-base and acid salt reaction. The main reactions of acid leached copper and copper ore are as follows: 3 bioleaching method Although there has been no research report on the copper leaching of electroplating sludge by biological methods, the biological leaching of copper-bearing ore has been extensively studied and applied in production practice. A large part of copper-bearing ore exists in the form of CuS. The treatment of wastewater in the electroplating industry uses the Na 2 S precipitation method to produce precipitates in the form of CuS. This similarity is of great significance for the biological leaching of electroplating sludge. significance. Moreover, the microorganisms lower the pH of the surrounding environment through life activities, and the acid leaching of the electroplating sludge is achieved by lowering the pH value. In 1981, Jiangxi Dexing Copper Mine cooperated with the Institute of Microbiology of the Chinese Academy of Sciences to carry out bacterial culture and bacterial shake flask test. The results showed that the copper grade was 0.117%, the particle size was -0.076mm, accounting for 90% of the ore, and the leaching was carried out. In the month, the leaching rate can reach 55%. In 1985, another 1000-ton industrial test was carried out, and mass production has now been realized. Practice has shown that microbial leaching technology is simple in process, low in investment, low in production cost, can effectively exploit and make full use of low-grade mineral resources, and is conducive to environmental protection, with good economic and social benefits. With the development and application of bio-leaching technology, the research on leaching microorganisms has also been greatly developed. From the initial discovery to the basic understanding of its physiological characteristics, leaching mechanism, medium leaching temperature and leaching acidity and other factors on the growth and leaching of bacteria, the initial monitoring of leaching microorganisms. Conclusion The electroplating sludge is treated by the process of this paper, and most of the copper can be recovered. At the same time, the harmful components in the sludge are effectively controlled to migrate to the soil and water during the stacking process, which can produce obvious social benefits and certain economic benefits. Sheet Extrusion Line,Plastic Sheet Extrusion,Plastic Sheet Extrusion Line,Plastic Sheet Extrusion Machinery WUXI HAOBANG MACHINERY MANUFACTURING CO.LTD , https://www.haobangmachinery.com