Study On Flotation Of Yi-tai Low-rank Coal Slime

In the developing country like china,the role of the low rank coal in the energysupply is more and more important. Before2000,about90%of the low rank coal inour country is combusted directly by the power plant for the combustion powergeneration, in recent years, our country is working to improve the energy efficiencyand reduce carbon emission. The fine coal slime is the important factor that restrictsthe economic to develop in the low thermal coal preparation plant, the mostfundamental and effective method to process the fine coal slime is flotation to raisequality. The oxygen containing functional group on the low rank coal surface reducesit’s hydrophobicity, and leads the low rank coal difficult to float.In the low rank coalflotation researches,the oily-bubbles flotation effect best,both reduces the reagentconsumption,and improves the coal slime flotation selectivity.But based on the risk ofthe oil bubble generator,the oily-bubbles flotation is also just stay on the laboratoryresearch stage, the advantage of the oily-bubbles flotation can’t play in the industry.The mechanism of the oily-bubbles flotation has not been explained accurately, if wecan research the mechanism clearly, and find a simple and safe method to replace theoily-bubbles flotation, then,the industrialization of the low rank coal slime flotation isjust around the corner. This paper uses the low rank coal of Yi-tai, to preliminaryexplore the mechanism of the oily-bubbles flotation, the main researching content isas follows:The coal slime sample through the0.5mm sieve first, then float with the materialunder the sieve. Using ordinary diesel do the conventional column flotation,theresults display as the follows: when the kerosene dosage is40kg/t, dosage of foamingagent is0.3kg/t,the cleaned coal yield is69.04%,clean coal ash is12.31%,the tail coalash is37.54%,and the combustible recovery is75.79%.When do oily-bubblesflotation to the test coal slime,the results display as the follows: when the kerosenedosage is2kg/t, dosage of foaming agent is0.3kg/t,the cleaned coal yield is74.84%,clean coal ash is9.32%,and the combustible recovery is84.96%.Condensatethe oil mist generated by the oil bubble generator during oily-bubbles flotation, andthen do column flotation use the condensation, the flotation result is:when thecollector dosage is2kg/t, dosage of foaming agent is0.3kg/t,the cleaned coal yield is65.97%,clean coal ash is12.05%,the tail coal ash is35.77%,and the combustiblerecovery is72.63%.The result showed that, when flotating with diesel,the reagentsconsumption is high,the content ash is high,and the burning body recovery rate is low; the oily-bubbles flotation technology float the low rank coal,the flotation effectis good and the reagent consumption is low; the condensate flotation contrast to theconventional flotation, the flotation reagent consumption reduces greatly,the cleancoal yield increases,and the clean coal ash decreases,but when contrast to the oilbubble,the effect is a bit poor.While analyze the condensate by infrared analysis and the GC-MS analysis,wecan reach that when the diesel change into oil gas the oxidation reactionhappened.The flotation test results and the analysis results prove that,oil changes arethe important factors that make the oily-bubbles flotation to have higher clean coalyield and lower agent consumption.We can research and develop the flotation agent that fit the low rank coalflotation by agent distribution,replace the oily-bubbles flotation,that would be a greatprogress of the low rank coal slime flotation industrialization, and will contribute tohigh-carbon energy use as Low-carbon energy, and reduce pollution in the coalutilization process. Processing of low rank coal slime by flotation can improve theefficiency of resource use, can increase their added value and increase the marketcompetitiveness of the coal enterprises, that would have very important significanceto improve the coal economic benefits.