A Resource Utilization Technology Of Josephinite Tailing

With the rapid development of modern technology and industry, our country has beendeveloping mineral resources on a large scale. This leads to a large number of tailingsnecessarily. However, the treatment method of tailings is always in a backward state, which isdue to low attention degree. The stockpiles of tailings results in resource wastage and landwastage. What’s even worse, improper stockpiling will bring serious pollution to theenvironment and destroy the ecological balance. Because of different physical and chemicalproperties, different tailings have distinctly different resource utilization ways. It increases thecomplexity of the tailings utilization. Therefore, tailings recovery treatment has a greatsignificance on resource conservation and environmental protection.Fujian Tripod Letter Industrial Co.Ltd. is a professional enterprise which engages innickel alloy smelting. It has about300,000tons of annual emissions ofjosephinite tailings.Large numbers of tailings stacking do harm to the local environment and restricts thedevelopment of enterprise. This study analysis deduces that the ingredients of smeltingemissions of josephinite tailings are mainly magnesium olivine, magnesium fayalite andmagnetite. Based on fundamental properties of tailing composition and combined with theactual situation of the enterprise with domestic and foreign research findings, the resourceutilization way of these josephinite tailings has been found out: to produce magnesiumhydroxide and white carbon black.Acid leaching of josephinite tailings is the pretreatment of resource process. It is alsothe most critical step of the whole process. Its purpose is to separate effectively the Si, Mgfrom other metal elements of the tailings. The present study has investigated the influence ofacid, acid concentration, solid-liquid ratio, reaction time, reaction temperature on acidleaching by means of single factor experiment. It has also fitted and optimized main factorsand results of that influence by means of response surface method. Considering the actualoperation process and cost, the selection of the optimum leaching conditions is: sulphuric acidconcentration30%, temperature80℃, time2h. Meanwhile, it has analyzed and verified thefeasibility of sulfuric acid leaching of josephinite tailings through thermodynamics. And it hasmade out dynamics fitting of josephinite tailings sulfuric acid leaching process throughimproved shrinking core model. As a result, it has inferred that the acid leaching process oftailings conform to the reaction layer diffusion control.Then it has made magnesium hydroxide powder, which conforms to the nationalindustry standard (HG/T3607-2000), from the sulfuric acid leaching solution of ferronickel tailings produced the acid leaching by means of ammonia-NaOH method.(Ammonia-NaOHmethod is to remove impurities by the oxidation of H2O2and ammonia method at first, and toadd15mol/L sodium hydroxide inside. Let it react at40℃to50℃for20minutes.)Besides, it has made white carbon black product, which conforms to the national industrystandard (HG/T3061-2009), from Sulfuric acid leaching slag by means of Binary compositeleaching method. Finally, it has realized theresource utilization of josephinite tailings, andreduced the pollution of these tailings.