Study On Preparation Of Zinc Ferrite From Zinc-bearing Gossan Ore By Roasting And Its Purification

Gossan is deposit body of oxides,water-containing oxides,secondary sulfates,various alum types and clay mixtures dominated by iron,manganese,calcium,silicon and aluminum,which is generally distributed in the upper or nearby areas of primary sulphide deposits.The gossan ore is discarded after mining,which increases the cost of mining production,causes the waste of metal resources,and the hazards of environmental pollution caused by long-term stacking.As a result,zinc-bearing gossan ore is studied in this paper,based on the mineral composition,characteristics of mineral properties and high content of zinc and iron minerals,using a new route of mineral resources materialization treatment technology,regulating the phase composition of zinc and iron minerals in zinc-bearing gossan ore,to study the preparation of zinc ferrate by direct roasting,the leaching of zinc ferrate by sulfuric acid and the purification of zinc ferrate,and using XRD?XRF?BET?SEM?EDS and other analytical methods to characterize the zinc-bearinggossan ore,the direct roasting of zinc ferrate and its sulfuric acid leaching and purification products.The main conclusions are as follows:(1)The suitable conditions for preparation of zinc ferrate by direct roasting of zinc-containing gossan ores are obtained.Taking the maximum content of zinc ferrate into account,the conditions are as follows:-0.074 mm ore sample,reaction zinc-iron molar ratio 1 ? 2,mechanical activation time 120 min,calcination temperature 1050?,calcination time 120 min,at this time,the content of zinc-ferrate in roasted products reached 88.6%.And taking saving energy consumption and the reaction product phase composition as simple as possible into account,the conditions are as follows:-0.074 mm ore sample,reaction zinc-iron molar ratio 1?2,mechanical activation time 120 min,calcination temperature 800?,calcination time 120 min,and the content of zinc ferrate in the roasting product reaches 75.3% at this time.(2)The effect of sulfuric acid concentration on the purification of zinc ferrate product is related to the content of zinc ferrate,but the effect of high sulfuric acid concentration on the purification of zinc ferrate product is significant.The effect of leaching temperature on the purification of zinc ferrate product is related to the concentration of sulfuric acid.The lower the concentration of sulfuric acid,the more significant the effect of leaching temperature is.The effect of leaching time and liquid-solid ratio on the purification of zinc ferrate is relativelysimple.With the prolongation of leaching time and the increase of liquid-solid ratio,the dissolution curve of purified zinc ferrate products will tend to be flat.The stirring speed is only related to the speed at which the sample is dissolved,and is not related to the degree to which the solution finally dissolves the sample,so the effect on the purification of zinc ferrate is little.(3)The suitable conditions for purification of zinc ferrate by sulfuric acid leaching are obtained.That is,sulfuric acid concentration140g/L,liquid-solid ratio 4?1,leaching temperature 80?,leaching time120 min,stirring speed 300 rpm.At this point,it can be purified to zinc ferrate content about 91%.(4)BET analysis shows that the isothermal adsorption desorption curves of the samples are all type III.The specific surface area,pore volume and average pore size of the two products containing zinc ferrate are 15.7 times,28.5 times,2.92 times,1.63 times,3.5 times and 1.48 times of that of gossan ore,respectively.In addition,the specific surface area of the purified product with low content of zinc ferrate is 9.66 times that of the purified product with high content of zinc ferrate,and its specific surface area and other parameters are the best.(5)SEM/EDS analysis shows that the particle agglomeration of zinc ferrate products prepared by roasting is more serious,its particle size is larger than that of gossan ore,and the grain boundaries appear moreobvious.The SEM diagram of high content zinc ferrate product and its purified product is almost consistent,and the SEM diagram of low content zinc ferrate product and its purified product is quite different.In summary,the direct roasting to prepare zinc ferrate,sulfuric acid leaching to purify zinc ferrate has been made clear in this paper,to obtain its preparation and purification conditions.A new idea for the utilization of similar refractory gossan ore by the research results,to lay a theoretical foundation for the development of new technology and technology for the preparation of zinc ferrate with real industrial application value,and the realization of the high efficiency development and utilization of zinc gossan ore in China.The research has high practical significance and academic value.