Beneficiation of Thermally Treated Brown Coal using Corona-Eletrostatic Separator

Abstract

The article discusses development of new approaches to design of electric separators aiming at increase in their capacity upon beneficiation of thermally treated powdered brown coal. On the basis of the developed theoretical backgrounds and obtained results of applied researches into beneficiation of thermally treated powdered brown coal theoretical proposals have been prepared for enhancement of design of experimental apparatuses for electromagnetic pulse impact and electrostatic separation aiming at creation of innovative technology and equipment for efficient beneficiation of thermally treated powdered brown coal, Grades B1, B2, and B3. During fine grinding of thermally treated powdered brown coal the particles are coagulated (that is, agglomeration and coarsening of particles), which reduces the yield of extracted organic constituent of brown coal. In order to increase the pulse impact for neutralization of coagulation (agglomeration of coal particles) ZAO "Compomash-TEK" has developed and tested a KMShU 110.02.000 apparatus of electromagnetic pulse action. Investigation into the influence of corona discharge current and discharge electrode voltage in electric separator with vertical drum has promote arrangements of technical proposals for enhancement of design of developed corona electrostatic separator: •increase in diameter of discharge electrode leads to decrease in corona discharge current under the same voltage applied; • at low values of corona discharge current the more significant factor, influencing on engineering properties of the separator, is the voltage applied to discharge electrode;• at high values of corona discharge current, higher than 90 ìA, the corona discharge current exerts the major influence on the separator engineering properties. Herewith, the higher is the corona discharge current, the better are the engineering properties: the extraction efficiency of brown coal mineral constituent into tailings increase from 14.8 % at corona current of 10 ìA to 78.6 % at corona current of 320 ìA;• while determining the influence of the distance between discharge electrode and collecting electrode on engineering properties of separation of thermally treated powdered brown coal in corona electrostatic laboratory separator with vertical drum it has been demonstrated that with increase in inter-electrode distance the engineering properties increase even at equal values of corona discharge current. Simultaneously with the yield of non-conductive fraction the extraction of mineral constituent increases. Investigations under laboratory conditions of operation modes of corona electrostatic separator with vertical collecting electrode (drum) and engineering results of separation of thermally treated powdered brown coal confirm high forecasted performances during beneficiation with capability to increase capacity by 5-10 times in comparison with conventional horizontal position of collecting electrode. The technical proposals for enhancement of the experimental designs are aimed at increase in beneficiatio...