Study On New Efficient Compound De-Magnesium Collector Of Difficult Separated Collophanite Ore

Phosphous is the important raw material of industry and agriculture. In our country, only a little phosphate ore easily beneficiates, all the other especial marine sedimentary phosphate rock (it is also called collophanite) which reserves account for over 75% is difficult to be separated. Because collophanite usually combines with dolomite, and their flotability is similar so that they can not be separated by the conventional flotation method. To this problem, according to the differences of physical chemistry properties between collophanite and dolomite, the raw material which is cheap and extensive had been choosen to synthesize a new efficient andcompound collector——MG, which was used for floating domolite. This kind ofcollector was also used to float actual phosphate ore, and was compared to sodium oleate and SR, the results of flotation indicated that MG was adapt to reverse flotation processing of collophanite, it is a kind of excellent collector. The flotation mechanism of MG was studied through Infrared Absorptions Spectra analysis, Zeta-potential mensuration, ultraviolet- visible light absorbing spectral analysis.Through a series of tests, the optimal synthetic method of MG was ascertained, which was direct saponification, the optimal reaction factor: raw material was not necessary to refine; the reaction time was 60 hours; the reaction temperature was 90°C; the raw material proportion, oil:NaOH = 10:2.5(weight). Furthermore, a kind of surfactant which is called TL was added into MG, the proportion was TL:MG=1:5(weight).In the research of flotation mechanism, the function group of MG molecule were ascertained to contain carboxyl and hydroxy group by Infrared Absorptions Spectra analysis. The flotation mechanism of MG reverse-floating dolomite was studied by measuring the Zeta-potential of collophanite and dolomite, Infrared Absorptions Spectra analysing the adsorption of MG onto the minerals surface, ultraviolet- visible light absorbing spectrum calculating the amount of MG which was adsorbed onto the minerals surface. These researches showed that MG was more easyly adsorded onto the surface of dolomite in feeble acidic solution because of pure dolomite charges positive as well as pure collophanite charges negative. Therefore, a lot of MG negative ions was adsorded onto dolomite, and that MG negative ions contained hydrophobic group, the hydrophobicity of dolomite was modified, the grains of dolomite were adhered to air bubble and float with them.The selectivity and collective strength of MG which were well than sodium oleate and SR were indicate by the flotation experiments of practice minerals. To the collophanite of certain region, Liaoning Province, the content of P₂O₅ was 19.50% and MgO was 6.87%. Using MG as collector to reversely float dolomite, its concentrate can be upgraded to 24.68% (P₂O₅), and the P₂O₅ grade of concentrate of sodium oleate as collector was only 21%. Simultaneity, the recovery of P₂O₅ of concentrate was 83.20%; the tailing contained P₂O₅ only 10%, it obviously declined compareing with sodium oleate. When direct-reverse flotation was engaged, if all the conditions were same completely ,but the kind of collector was changed, the P₂O₅ grade of concentrate of opening circuit was upto 32%, the P₂O₅ recovery of which reached 86.15% when the collector was MG, the P₂O₅ grade of tailing was only 3.67%. If the collector of reverse flotation was SR, its P₂O₅ grade of concentrate was 78%, and the P₂O₅ grade of tailing was 7.48%.