Study On Reverse Flotation Desliming And Collectors Choosing Experiment And Mechanism Of A Steam Coal

Nowadays,flotation is primarily separating technology of fine-grained coal in our country.But as the coal gets inferior and difficult floated coal slime increase,there is a low efficiency in conventional flotation process,large flotation reagent consumption problem. Flotation was divided into positive and reverse flotation,in conventional flotation,with a hydrocarbon oil as collector,coal became foam products,high-ash minerals become tank products.Reverse flotation is the addition of an inhibitor collector and minerals,minerals become foam products.Reverse flotation can reduce consumption flotation devices,load and energy,because of flotation feed coal is much larger than the amount of other minerals,gangue flotation can reduce the rate of fine mineral flotation yield from50～70percent to30～50percent.Reverse flotation is mainly used to deal with the oxidation and low rank coal,which has a poor hydrophobic,and difficult in using conventional flotation to separate.This study used different type of collectors and different degrees of metamorphism and oxidized coal samples (coal from pingsuo and Ningxia) conducted a study of reverse flotation tests,preliminary exploration of the anti-slime flotation process,trying to find a high efficient collector.Found that depressor can increase the anti-flotation efficiency,zero conditioning procedure can reduce the collector usage.The article also predominantly pure minerals in coal flotation studies and preliminary analysis of the mechanism.The main contents of this paper are:(1) Taking Amines(DDA and DN18) Amine halide(DTAC and CTAB) composite collector(BKG30) as collectors,Choose a different degree of metamorphism and oxidation of coal samples (coal from pingsuo and Ningxia) as an object of study subjects,and the samples were analyzed, including: proximate analysis,particle size analysis,infrared spectroscopy and X-ray diffraction patterns analysis.(2)Taking DDA、DTAC、BKG30、CTAB and DN18as collectors,the effect of various collectors on the reverse flotation have been investigated of a coal from pingshuo.include:Conventional flotation,flotation with depressor and zero conditioning procedure experiments.DDA and DTAC has a good effect in flotation,With less collectors and high efficiency.BKG30and CTAB has less slime better results.DNis also has a good effect on flotation of the coal,but a large amount of collectors was needed.zero conditioning procedure can reduce the collector usage.(3) The effect of Dextrin dosage and pH value on the reverse flotation have been investigated with better collectors.Dextrin is necessary to improve the selectivity in this process.Dextrin amount increases to a certain extent,Flotation tailings ash and reverse flotation efficiency were little changed.The best reverse flotation result was obtained under an acidic pH of4for this coal.(4) According to the same manner as described above,the effect of various collectors on the reverse flotation have been investigated of a coal from Ningxia.Find different flotation collectors role of different rank and degree of oxidation of coal samples.BKG30has a good effect in flotation,With less collectors and high efficiency.DTAC and CTAB has less slime better results.(5) With five collectors of coal kaolinite,quartz,calcite mixture of primary minerals and coal flotation experiments was conducted.When Five collectors flotat coal mixture of kaolinite,collectors consumed in large,with poor selectivity. But when Five collectors flotat coal mixture of quartz,calcite coal mixture,pharmaceutical consumption is better flotation effect.Kaolinite in coal may be difficult to flotate,to make reverse flotation consume large collectors and make low flotation efficiency.(6) Taking ningxia Coal and pingshuo coal flotation products to infrared spectroscopy and X-ray diffraction patterns analysis.X-ray diffraction analysis revealed that dodecylamine hydrochloride and sodium dodecyl trimethyl ammonium chloride have a good flotation on kaolinite,quartz and calcite for pingshuo coal.BKG30have a good flotation on kaolinite,quartz and boehmite for ningxia coal,there is no flotation on magnetite.Taking ningxia Coal and pingshuo coal flotation concentrate to infrared spectroscopy,we find that there was a similar from coal and reject products of the Infrared spectra picture,it did not produce significant new peaks,each collector occurred surface physical adsorption.