| The main gangue of Carbonate-hosted Type Lead-zinc ore is dolomite,which usually causes the problem of excess magnesium in the flotation concentrate.The product can further lead to the serious damage of pipeline equipment in the smelting process.To solve such problem,this paper took the lead-zinc from four mining zone(Maolulin,Yuhe,Shayan and Jinpo)in Guizhou province as the research object.First,through several analytic methods,such as X-ray fluorescence spectrum analysis,X-ray diffraction analysis and mineral liberation analyzor,The ore’s chemical multi-element composition,phase composition and target mineral intercalation characteristics and other technological mineralogical parameters were studied;and on this basis,inhibitor screening tests and technological process exploration tests were carried out and the best agent system was obtained.Finally,through methods such as pure mineral flotation test,Zeta potential measurement,IR spectroscopy analysis and Materials Studio software simulation calculation,the inhibitory mechanism of agents and minerals was explored.The main research results are as follows:(1)The results of process mineralogy show that the valuable element of the lead-zinc ore is zinc,and the harmful element is magnesium;the metal minerals in the ore include sphalerite,galena and pyrite,etc,and gangue minerals mainly include dolomite,Calcite and quartz.Zinc and magnesium exist in the ore in the form of sphalerite and dolomite,respectively.In the case of-0.075 mm accounting for 75%,zinc and magnesium are more evenly distributed in each particle size.In addition,the magnesium content in the on-site concentrate is relatively high,reaching an average of 3.15%,and magnesium mainly exists in the form of dolomite,which is inter-embedded with sphalerite in the form of adjacent symbiosis,metasomatic continuous growth,and package inlay.The intercalation relationship and particle size distribution of sphalerite and dolomite explain the reason why the magnesium in the concentrate exceeds the standard.(2)According to the characteristics of high magnesium content in the field concentrate,the reagent conditions of the ore were studied.Firstly,the dosage of existing agents is optimized.After optimization,the results show that the dosage of calcium oxide is 1500 g/t,copper sulfate is 300 g/t,butyl xanthate is 140 g/t and terpineol is 100 g/t.The combined inhibitor composed of sodium hexametaphosphate and water glass can better reduce the magnesium content in the concentrate.When the combined inhibitor(1:1)dosage is 400g/t,under the closed-circuit test process of "one rough,four fine and three sweeps",the zinc grade is 51.88%,the recovery rate is 92.58%,and the magnesium grade is 2.38%.Concentrate comparing the test product with the field product,the magnesium content in the concentrate dropped by 0.77 percentage points.At the same time,the zinc recovery rate increased from 91.59% to 92.58%,an increase of 0.89 percentage points.The grade is 1.91% higher than that of the on-site zinc concentrate,achieving the expected effect of reducing magnesium in the concentrate.(3)The pure mineral flotation test results show that: under the combined inhibitor sodium hexametaphosphate-water glass system,the recovery rate of sphalerite is high(93%-95%),the recovery rate of dolomite is reduced to 1.04%.It has little effect on the recovery of sphalerite by the combined inhibitor and has a strong inhibitory effect on dolomite.Zeta measurement shows that the combined inhibitor has a small change on the surface potential of sphalerite and a greater impact on the surface potential of dolomite,indicating that the inhibitor has a stronger inhibitory effect on dolomite.The infrared spectrum of the interaction between the inhibitor and dolomite shows that sodium hexametaphosphate and water glass have an adsorption effect on dolomite,and the chemical adsorption of the former is stronger than the latter.When the combined inhibitor acts on dolomite,the infrared spectrum of dolomite changes more than when the single agent acts,indicating that the combined inhibitor has a stronger effect than the single inhibitor.The simulation results of Materials Studio software show that the adsorption energy of sodium hexametaphosphate and water glass on the surface of sphalerite are both positive,while the adsorption energy on the surface of dolomite is negative,and sodium hexametaphosphate is on the surface of dolomite.The negative value of adsorption energy is greater,indicating that the adsorption effect of sodium hexametaphosphate on dolomite is stronger.It can be concluded that a single inhibitor has a certain inhibitory effect on dolomite,and a combined inhibitor has the best inhibitory effect on dolomite,which can achieve the purpose of reducing the magnesium content in the concentrate. |
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