| Ammonium jarosite was an industrial waste which produced in the process of zinc hydrometallurgy.Massive hoarding of Ammonium jarosite,land wastage and environmental pollution were due to the lack of low-cost Ammonium jarosite-treatment technology in the domestic and overseas now.Therefore,it was very important for environmental protection and social significance to treat or utilize Ammonium jarositeThe cinder of Ammonium jarosite was taken as the research object and a scheme for resource utilization of Ammonium J arosite was put forward in this paper.The scheme roasted Ammonium jarosite firstly,then the valuable metal elements were recovered by washing and leaching process,and finally the residue,such as the cinder of Ammonium J arosite,water bath slag and leaching residue were prepared to make the sulphoaluminate cement clinker.In order to make the best use of the utilization of Ammonium jarosite,reductive baking of Ammonium jarosite with the addition of coals,and hot acid leaching of iron and zinc elements from roasted Ammonium jarosite,and the preparation of sulphoaluminate cement from Ammonium jarosite were studied respectively in this paperIn order to study the effect of coal content on iron,sulfur content and their phase in roasted Ammonium jarosite A,the different mass fraction of lignite powder was added to Ammonium jarosite.lt was found that the sulfur content of roasted residue,which was roasted with coal content of 15%at 1000?,was the lowest,and the sulfur content in roasted residue decreased with the increase of temperature.When Ammonium jarosite was roasted with coal content of 0%at different temperature,the sulfur content of roasted residue is highest.The quality and sulfur content of roasted residue were decreased after water bath,and the maximum sulfur content could be reduced to 2.13%.The roasted residue and water bath residue contained iron series and chalcogenide,they could be used as the raw material of sulphoaluminate cementThe effects of calcination temperature,leaching temperature,sulfuric acid concentration and liquid-solid ratio on iron and zinc in roasted residue were studied.The results showed that the burn out rate of Ammonium jarosite B increased with the increase of temperature,and ZnFe2O4 formed rapidly when the temperature was higher than 600?.The optimum scheme of hot acid leaching of roasted residue was under the conditions of roasted residue of 500?,stirring speed of 350r/min,sulfuric acid of 2.5mol/L,leaching temperature of 90?,and leaching time of 2h.When the preparation of chloroaluminates cement by using Ammonium jarosite A as raw material,the effect of calcination temperature and holding time were studied,and the influence of gypsum content on cement stability and paste strength were studied.And the poison of cement block,which contained C4A3(?) was 49.49%,was extracted by sulfuric acid&nitric acid method.The results showed that the sulfur fixation reaction might exist in the process of firing sulphoaluminate cement,which led to the content of calcium sulfate,was higher than that of theoretical calculation.When the sulphoaluminate cement clinker which prepared from Ammonium jarosite is in hydration,the free calcium sulfate in the sulphoaluminate cement clinker whose C4A3(?) content were 42.98%and 49.49%could meet the gypsum amount needed for hydration,and there is no need to add calcium sulfate to sulphoaluminate cement clinker.When the content of the cement test block whose C4A3(?) content was 73.09%and gypsum content was 2%and 4%separately was excessive in hydration,and ettringite would continue to form after the cement test block reached a certain strength,which would eventually lead to the expansion and cracking of cement test blocks.The Poisons leaching value of the cement test block whose C4A3(?) content was 49.49%and gypsum content was 0%all met the national standard,thereby it prevented secondary pollution of the sulphoaluminate cement clinker which prepared from Ammonium jarosite. |
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