| Chinese magnesite resources are abundant,but high-quality magnesite resources are decreasing and it is urgent to study the efficient impurity removal technology of low-grade magnesite.In this paper,under the flotation system of sodium hexametaphosphate as inhibitor,the flotation behavior of minerals under different kinds of collector flotation conditions was studied,and the magnesite decalcification flotation was summarized based on the difference in mineral flotation behavior.The system provides a reference for the purification of low-grade magnesite ore.Firstly,the concentration of collector,the pH of the slurry and the amount of inhibitor sodium hexametaphosphate in the flotation system of single collector sodium oleate,oleic acid and lauryl phosphate were studied respectively.The impact of dolomite flotation behavior.Secondly,the combination of oleic acid and lauryl phosphate,oleic acid and n-octanol,oleic acid and undecyl alcohol,oleic acid and dodecyl alcohol,oleic acid and benzoic acid,and oleic acid were studied.The flotation behavior of magnesite and dolomite in the flotation system with salicyl hydroxamic acid,the ratio of collector,collector concentration,pulp pH and the amount of inhibitor sodium hexametaphosphate.Finally,through the data comparison,the best flotation separation agent system for magnesite and dolomite was obtained.The results showed that the molar ratio of the combination of collector oleic acid and lauryl phosphate was 8:2(oleic acid:lauryl phosphate)and the total amount of combined collectors.3.54×10-4mol/L,the pH value of the slurry is 8.The single mineral flotation behavior of magnesite and dolomite is different under the condition of 0.49×10-4mol/L sodium hexametaphosphate(magnesium).(Mine:50.55%,dolomite:8.75%),can achieve flotation separation between magnesite and dolomite.In order to verify the above-mentioned chemical system for the separation of magnesite and dolomite,the magnesite:dolomite was tested as a binary mixed ore flotation test of 1:1 and 9:1.The results showed that in the absence of inhibitor sodium hexametaphosphate,the single collector sodium oleate flotation system had a CaO grade of 17.28%in the concentrate at a ratio of 1:1,and 2.25%at a ratio of 9:1.It shows that magnesite and dolomite are similar in floatability,and it is impossible to achieve effective separation between minerals.Under the combination of collector oleic acid and lauryl phosphate system,the CaO grade in concentrate is 1:1.At 8.46%,the ratio is 1.75%at 9:1,indicating that the combined collector oleic acid has better selectivity than the single collector sodium oleate compared with lauryl phosphate;In the case of sodium metaphosphate,under the single collector sodium oleate flotation system,the CaO grade in the concentrate is 2.17%when the ratio of mixed ore is 1:1,and the ratio is 0.55%at 9:1,which greatly improves the calcium removal effect,but The recovery rate of magnesite in the concentrate is low,40.96%(mixed ore ratio 1:1)and 33.50%(mixed ore ratio 9:1),indicating that sodium hexametaphosphate inhibits dolomite at the same time.Magnesite;combined collector oleic acid and lauryl phosphate system,when the ratio of mixed ore is 1:1,the CaO grade in the concentrate is 1.26%,and the ratio is 9:1.And the recovery rate of magnesite in the concentrate is 68.52%(mixed ore ratio 1:1)and 48.01%(mixed ore ratio 9:1),which is not only enhanced compared to the single collector sodium oleate.In addition to the calcium effect,the inhibition of magnesite by sodium hexametaphosphate is also reduced,thereby allowing better separation of magnesite from dolomite.The mechanism study shows that the potentiodynamics of the magnesite and dolomite move to the negative direction after the addition of the combined collector,and the surface potential of the mineral surface is not significantly related to the concentration and ratio of the combined collector.Spectroscopic analysis showed that the combination of oleic acid and lauryl phosphate was chemically adsorbed on the surface of magnesite and dolomite,but the adsorption amount of magnesite was much larger than that of dolomite;infrared spectrum and XPS detection showed combination The adsorption of oleic acid and lauryl phosphate on the surface of dolomite is weaker than that on the surface of magnesite and has good selectivity. |
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