Study On The Process And Mechanism Of Flotation Separation Between Spodumene And Beryl

Lithium and beryllium are two important rare metals, while spodumene and beryl are the main minerals from which lithium and beryllium are extracted in our country at present respectively. Keketuohai rare metal Mine in Xinjiang is the largest lithium and beryllium metal mine in China, but its run of mine is becoming lower, and this leads to the increasing of reagent consumption and the rising of production cost. This problem is expected to be solved by searching a new collector and modifiers, which can depress spodumene and beryl selectively.Various collectors have been used for the flotation of spodumene and beryl, in order to find the flotation regularity of these two minerals. The influence of low molecular organic depressants such as citric acid on the floatability of spodumene and beryl, as well as inorganic modifiers has been studied through flotation tests. This study includes pure minerals flotation tests, flotation separation of artificial mixed minerals and pilot flotation tests. The results of all of these tests are satisfying. Various measurements techniques have been carried out, including Zeta potential determinations on the surface of these two minerals, infrared spectroscopy and so on, to find out the regularity and mechanism of collectors, activating metal ions, inorganic and organic modifiers on spodumene and beryl at the end of this paper.The results of pure minerals flotation tests indicate that the floatability of spodumene and beryl is the highest using a new collector YOA-15, comparing with sodium oleate, C_7-9 alkyl hydroxamic acid and sodium dodecyl sulphonate. Fe³⁺ and Ca²⁺ ions show a high activating reaction on the flotation of spodumene and beryl. Fe³⁺ ions work best under neutral pH, while the most efficient environment of Ca²⁺ ions is at very high pH values. Fe³⁺ ions show sufficient activation on spodumene and beryl at a low concentration, and Ca²⁺ ions can't activate the minerals sufficiently until the concentration of it is high enough. Na₂S has a goodselective depression between spodumene and beryl activated by Fe3+ ions, but has no depression to the two minerals activated by Ca2+ ions. Citric acid and lactic acid can depress these two minerals selectively, while this selectivity is poor. Tartaric acid and oxalic acid have a strong depressing action on these two minerals, and this action has no selectivity. Sodium hexametaphosphate and sodium EDTA present better selectivity for depressing of these two minerals than Na2S, which is used in the processing of spodumene and beryl ores at present.The flotation tests of aitifici?! mixed m?rerals have been carried out with sodium EDTA, Na2S and Sodium hexametaphosphate as modifiers, the results indicate that these modifiers can separate spodumene and beryl efficiently. And sodium EDTA does best. The products in the flotation cell containing O2O 4.82%, and the froth products containing BeO 9.566% were achieved, after the mixed minerals have been processed using sodium EDTA in which spodumene: beryl equals 1:1, when spodumene: beryl is 3:1, we can get the products containing U2O 6.32% in the cell, and the froth products containing BeO 6.246%. The pilot tests show that compounding concentrates containing U2O 5.21% and BeO 1.955% can be obtained from the run of mine containing U2O 0.22% and BeO 0.065%, under the reagent scheme ascertained by the pure minerals flotation tests. The concentrates of spodumene and beryl containing Li2O 5.81%> BeO 0.871% and Li2O 2.46%> BeO 6.29% have been achieved respectively after the processing of separation. This agrees with the contract.The results of mechanism study show that Ca ions react on the minerals surface by physical adsorption, while Fe3+ ions react on the minerals surface by chemical adsorption. Sodium EDTAand Na2S tend to be absorbed onto spodumene surface rather than beryl surface since both minerals have been activated by Fe3+ ions, and change the PZC of spodumene largely. When the minerals have been activated by Fe3+ ions, the adsorption of YOA-15 on the surface of minerals becomes intense. The measurements of infrared spectroscopy also show that there is a newsubstance appearing on the surface of the minerals, when the collector reacts on the Fe3+ activated minerals. This indicates that YOA-15 is adsorbed onto the surface of the two minerals by chemistry.