Experimental Study On The Reverse Flotation Of The Lignite From Xilin Haote

Reverse flotation of lignite slime from Xilin Haote, Inner Mongolia was concerned inthis paper. Researches were conducted on analysis of its surface property, selection offlotation environment and dosage of reagents. The Reason to reverse flotation was alsodiscussed in this paper.Instrumental analysis showed that quartz (strong hydrophilic) and kaolin (easy to ultra-slime) were the main impurity in the lignite slime sample. Size and density analysis showedthat lots of ultra-fine slime with high ash content (-0.045mm slime with the yield of43.61%and the ash content of62.75%) and low density materials (-1.50g/cm3low density materialswith the yield of42.89%) were in the lignite slime sample.Selection of flotation environment was carried out, conventional reagents (kerosene ascollector, octanol as foaming agent) were void; tween60brought about reverse flotation withlow the efficiency; TTAB also brought about reverse flotation, however the flotation indexeswere irregular with the increase of TTAB. Dodecylamine also brought about reverse flotation,and the flotation indexes were regular with the increase of Dodecylamine.2-ethyl hexanol,glycerin monostearate etc. were void. The flotation indexes were not influenced bytemperature and pH value in the case of Dodecylamine.Experimental study on the dosage of reagents was carried out. In the case ofdodecylamine(surfactant), octanol(foaming agent), corn dextrin(inhibitor), the dosage ofdodecylamine was significant to the float yield, and the dosage of octanol was significant tothe float ash content, and the dosage of corn dextrin didn’t affect the flotation indexesobviously.Exploration of the reason to reverse flotation of the lignite slime sample was carriedout.Size test of the products showed that the ultra-fine slime with high ash content made upthe largest part of the float, and the coarse particle with low ash content made up the largestpart of the sediment; flotation of the ultra-fine slime showed that most of the material madeup the float; flotation speed test showed that the ash content is similar at variable time delaysand the flotation was stable; scanning electron microscope of the products showed thatultra-fine slime was absorbed with the coarse particle. The reason to the reverse flotation wasmainly the floation of the ultra-fine slime, and the ultra-fine slime had poor selectivity. Therewas corresponding increase of the coarse particle in the float with the increase of the floatyield.