Research On The Compounded Frother And The Performance

New frothers that being excogitated in recent years are mostly compound with alcohol, ether, ketone and ester, therefore, compounding of the four main components can generate a good foam performance and improve yield and grade of flotation concentrate. And these new frothers are mostly mixed with couples of reagents, cause mixed reagent has better flotation effect than single reagent, so new compounded frother are widely used in metallic ore separation. However, these new frothers are mostly used in metallic ore, and rarely used in coal ore. What coal flotation condition should be if compounding alcohol, ether alcohol and ester frothers to be a new frother?This paper focus on the study of 1#bituminous coal and 2#bituminous coal in Wangfenggang, compounding alcohol, ether alcohol and ester frothers to produce a frother that suitable for coal separation. Firstly, by exploring size, density and phase composition of coal, we can predict the floatability of 1#bituminous coal and 2#bituminous coal. Secondly, Single factor optimization test is conducted with three frothers-ether alcohol, ester and alcohol frother, and four indexes-flotation clean coal yield, ash content, improved floatation index and combustible material recovery. Based on tests'result, dipropylene glycol butyl ether, diethyl phthalate and sec-caprylic alcohol are selected and compounded homogeneously. Regression analysis and optimization are performed to the result of homogeneous compounding test, and clean coal yield and ash content are taken as indexes, finally an optimal compounded frother scheme comes out:dipropylene glycol butyl ether 18g/t, diethyl phthalate 22g/t and sec-caprylic alcohol 35g/t. For 1#bituminous coal, clean coal yield is increased by 4.82 percent, clean coal ash content is decreased by 0.68 percent, improved floatation index is improved by 5.98 percent, and combustible material recovery is reduced by 6.05 percent, when it compared with same dosage of sec-caprylic alcohol. And for 2#bituminous coal, clean coal yield is increased by 3.10 percent, clean coal ash content is decreased by 0.31 percent, improved floatation index is improved by 3.43 percent, and combustible material recovery is reduced by 4.13 percent, when it compared with same dosage of sec-caprylic alcohol.Properties of preconcentration reagent and compounded frother are under determination, and mechanism of compounded frother is under discovery. The maximum altitude of foam generated by compounded reagent is 191mm, and half-life is 126s, reagent's lower surface tension is 14.61mN/m, and after treatment of reagent, contact angle of coal slime and water is 77°. Comprehensively, compounded frother has a better foaming and stabling foam ability than three single reagents. This is because nonpolar group in compounded frother has benzene ring and eight-carbon-chain alkyl, and its polar group has large amount of propanediol and ethyl formate, increasing the maximum altitude of foam, and enhancing the foaming ability. Increasing number of long carbon chain alkyl in nonpolar group and functional groups in polar group leads to increase of half-life of foam generated by compounded reagent, enhance of hydrophobicity, enlarge of reagent's lower surface tension, and magnify of stabling foam ability.