Column Floatation Study On Coal Slime Water With High Concentration By Extending Mineralization

Cyclone micro-bubble flotation column(FCMC) shows a significant advantage in the processing of coal slime with high content. The development of dense medium coal preparation technology and enhancement in the mechanization of mining, and the less water consumption of dense medium coal preparation than that of jigging, make the coal slime content increased, and the coal slurry concentrations escalated, which conducts maladjustment of FCMC to separate the high concentration pulp in the specific conditions.This article aims to solve the difficult problem of reducing ash of high concentration fine coal slime, and designs a new pre-flotation flotation column(NPFC). The feed of NPFC is mineralized in the feed pipe, part of them is pre-floatated in the first section column, and the rest get into the second section column and is sorted. Firstly, the FCMC was tested on different pulp concentrations, and the appropriate column height of 1800 mm and the high pulp concentration of 120g/L which is difficult to deal with was found, and were regarded as the initial conditions of NPFC. Then, to determine the more appropriate parameter levels, the new structure parameters and operating parameters was tested by NPFC with the method of multi factors termwise test. Finally, the test was conducted about different pulp concentrations with two feeding mineralization pressure by NPFC, and the sorting result of two flotation columns was got a comparative analysis.The research results show that: The clean coal ash increased with the increase of pulp concentration, the excessively high concentration will make the separation effect deteriorated. Under the separation of NPFC, the different feeding pressure make a different degree of pre-mineralization of the feed, the changing of the structure of first segment could get optimization of its internal flow field, change the separation space of first segment and the separation stability degree of second segment. As a result, the lower clean coal ash was obtained. When the slurry concentration run up to 120g/L, the cleaned coal ash would reach 11.22% and exceed 9.50%; the feed mineralization pressure of 0.05 MPa make a NPFC clean coal ash of 10.73%, which is 0.49% lower than that of FCMC; the feed mineralization pressure of 0.07 MPa make a NPFC clean coal ash of 9.32%, which is 1.90% lower than that of FCMC; When the concentration continues to rise, the clean coal ash increases, but still lower than that of FCMC on concentration of 120g/L. The experimental study on concentrations by NPFC shows that clean coal ash was lower than that of FCMC under each pulp concentration, cleaned coal yield and perfect index of flotation was reduced correspondingly. Adjusting the feed mineralization pressure can improve the index of separation. The conclusion can be drawn by this thesis: NPFC can guarantee the clean coal ash on separation of fine coal slime water with high concentration than FCMC.