Introduction to several mainstream coal preparation technologies in China
To be successful. A brief introduction to the principles of these methods is now available. The electro-election method is based on the difference in electrical conductivity, permittivity, triboelectricity, adhesion, and the like of the raw coal components. The magnetic separation method is based on the use of different magnetization coefficients of the light and heavy density levels of the raw coal. It is usually carried out using a strong magnetic roller type or a roller magnetic separator. The adaptation particle size is 0.1-1(3)mm. The air suspension option uses the principle of a boiling layer. In the former Soviet Union, a prototype industrial test with a capacity of 100t was carried out (sorting 25-100mm). The x-ray selective method is sorted by using coal and vermiculite for different absorption and diffusion characteristics of x-rays. As for the sorting method according to the characteristics of shape, damping and the like, it has been only a few assumptions so far, but the selective crusher (using different volume strengths of coal and vermiculite) has been industrially applied. Other coal preparation methods under study include chemical coal preparation. This is mainly driven by the increasingly strict requirements of environmental protection for sO2 emissions. For example, the United States has enacted a new energy standard, and almost all coal needs to be desulfurized. Although the coal is burned by physical method Desulfurization before burning can play a big role, but it is impossible to select all the coal that meets the new energy use standards of the Environmental Protection Agency. It is still necessary to carry out the purification of flue gas after combustion. Therefore, people began to study the chemical desulfurization technology before coal combustion, in order to obtain low sulfur, low ash, high calorific value Quality products. But for now, this technology is still in the development research stage. At present, there are two researches on chemical coal preparation technology carried out in the United States: density dissolution method and microwave treatment method. Density is the dissolution process after the physical separation of the coal (particle size of 1.4-0mm about 5% moisture) into a 340-390 ℃ of NaOH and KOH molten pool, coal organic matter, and most of the sulfur, pyrite ore The substance reacts with the KOH and NaOH mixture and dissolves it in the coal. Alkaline sulphide sulfur conversion and polysulfides, minerals are converted to basic almost aluminosilicates and other water-soluble and acid byproducts. Since the caustic solut has a density of about 1.8 g/cm 3 . Therefore, the coal floats up in the pool, and the sinking density is greater than 1.8g/li. Square centimeter of soluble minerals. The treated coal is washed with water, filtered and recovered, and then pickled in 10% sulfuric acid solution, and the mixture of acidic water and coal is filtered again to recover the final coal product. The filtered filtrate and the acid washed filtrate are washed separately. The whole process of microwave treatment is: mixing of coal and caustic, drying, microwave irradiation, water washing and pickling. However, during the two adjacent microwave treatments, a certain washing and pickling step can be omitted. The microwave treatment method, like the density dissolution method, is currently in the laboratory research stage. At present, several popular coal preparation technologies popular in China have been introduced in detail. China has a vast territory, and the situation of each coal washing plant is different. Everyone should combine their own actual conditions to choose the coal preparation technology that suits them. Pir Panel,Pir Sandwich Panel,Pir Insulated Panels,Chiller Room Panels Shandong Atlas Refrigeration Technology Co.,Ltd. , https://www.atlascoldroom.com