Flotation intensification of low-rank coal using a new collector prepared by composition and following plasma

WANG Dapeng; LI Wenxiu; WANG Zhenfei; XIAO Xiong; ZHANG Guodong

doi:10.13225/j.cnki.jccs.2022.1213

Abstract：Flotation reagents have a significant impact on the flotation of low-rank coal.In recent years,more re-search had been conducted on the low-rank coal flotation using chemically modified hydrocarbon oil as collector.With regard to its fast modified rate,environmental compatibility and high efficiency,the plasma modification is considered as a promising treatment technology for the production methods of low-rank coal collector.Previous research shows that the collectors modified by plasma using traditional single non-polar oil as raw material cannot reduce the a-mount of regent.In this study,a new collector modified by plasma using traditional fossil oil and secondary octyl alco-hol as raw materials was used to enhance low-rank coal flotation.The chemical structure of new collector,adsorp-tion mechanism,flotation performance of coal and collector were investigated through the flotation test,GC-MS,XPS,FTIR and quantum chemistry calculation.Under the optimal formulation conditions of 80%of dodecane and 20%of sec-octyl alcohol,10 min of plasma treatment,and 2.5 kg/t of new collector consumption,the flotation results show that the yield of clean coal and the combustible body recovery rate are 55.32%and 64.81%,respectively.The clean coal yield is 15 percentage points higher than the clean coal yield before treatment,and the dosage of rea-gent is reduced by more than 50%.Through mixing and following plasma treatment,the dodecane and sec-octyl alcohol are translated to the mixture which contains dodecane,sec-octyl alcohol,dodecanol,dodecanone and long chain oxy-genated organic compounds.The adsorption energy between long chain oxygenated organic compounds which are easi-er to interact with the oxygen-bearing functional and the surface of low-rank coal is above 54 kJ/mol.The hydropho-bicity and floatability of low-rank coal are improved through above adsorption.The C—C/C—H functional on coal slime surface is 7.41 percentage points higher than that on raw coal,the O groups content on coal slime surface is 2.61 percentage points lower than that on raw coal.