Study On The Separation Mechanism And Application Of Liquid-Solid Fluidized Bed Coarse Slime Separator

The separation of coarse slime has become the key point affecting the clean coal yield. Application of a great deal of dense-media cyclones of large diameter and flotation columns has improved the product quality and the separation effect, but which has reduced the separation effect of coarse slime which is between gravity separation and flotation. The separation theory of Liquid-Solid Fluidized Bed coarse slime separator(LSFBCSS)can match the characteristics of narrow granularity bound, low density separation of coarse slime. It is a new technology with excellent separation results and with simple configuration. The research about it has just begun in China. Excogitate of LSFBCSS with independent intellectual property has the pivotal imputes to the development of coal separation technology of our country, especially to the evolution of coarse slime separation technology. It has great significance indeed.The research of distributor combining the multi-pipe distributor with the side-flow distributor used in chemical engineering are carried out, finally the new separator is designed and patented. After the process of conceiving principium model, model design, laboratory tests, simulation of inside flow, research of associated hydrokinetics, research of separation stratification theory, construction of pilot test system and pilot test, the Liquid-Solid Fluidized Bed Separator 2FBCC-1500 was designed and manufactured, and the relevant industrial trial has been carried out in Chengzhuang and Gedian preparation plant respectively. The results have been concluded as follows: In Chengzhuang preparation plant, the separation trial was carried out with the tailings of the spiral separator,the E values of particles more than 0.125 mm are all between 0.07 and 0.10 and the eligibility clean coal yield is more than 30% have been achieved, while the ash content of cleaned coal is between 10% and 11%, the ash content of tailings is more than 63% and the clean coal yield is between 73% and 76% in the separation of coarse slime. The separation effect is better than that of the spiral separator markedly, and the clean coal yield of the whole preparation plant increases more than one percent. The separation effect of particles larger than 0.125mm in Gedian preparation plant is equal to that of Zhangshuanglou preparation plant with the import coarse slime separator, but the pollution of feed in former is more serious. The clean coal yield of the whole preparation plant increases four percent,which will bring great benefit in economy. The industrial test shows that the LSFBCSS has been reasonablely designed with high stability, low undulation in results, lofty auto-control system and easy operation.According to the inefficient separation effect of the coarse slime existing in most of domestic coal separation technology, three stage coal separation technology adding Liquid-Solid Fluidized Bed coarse slime separation has been applied for the first time. According to the characteristics that all the fine slime with high ash content goes into the overflow, which will increase the ash content of the clean coal, the opinion that reducing the content of fine slime of high ash and strengthen the effect of desliming is the key point to the successful use of LSFBCSS in industry is pointed out for the first time, also the new flowsheet for coal recovery using Liquid-Solid Fluidized Bed and flotation column, including desliming and concentrating of the feed, desliming and dehydration of the overflow product of Liquid-Solid Fluidized Bed Separator, has been developed. The separation capability of LSFBCSS has reached the design requirement and filling a domestic gap in this field.