Resrearch On The Extraction,preparation And Technology Of Battery-grade Manganese Sulfate From Tungsten Smelting Slag

Large exploitation and utilization of tungsten resources has resulted in the accumulation and landfilling of tungsten smelting slag.Due to the different kinds of tungsten and processing technologies are different,the components of tungsten smelting slag are also complex and complicated.The processing is relatively complicated and the cost is relatively low.High is often not worth the candle.The random deposit of tungsten smelting slag not only causes the waste of resources,but also sometimes pollutes the environment.The rise of battery-grade manganese sulfate in recent years has pointed out a way to treat tungsten smelting slag.The manganese metal contained in the tungsten smelting slag can be extracted to prepare manganese sulfate.Tungsten smelting slag contains many types of metal elements:manganese,iron,calcium,and a little of heavy metal ions.This paper takes a tungsten smelting slag from Ganzhou as reaction raw materials,removes iron,calcium,sodium,heavy metal ions,etc.through the process of impurity removal to prepare a battery-grade manganese sulfate.The product is characterized to verify whether the product is qualified.The main research includes the following:?1?Determine the elemental composition Fe,Mn,Ca,the main iron and manganese crystal compounds Fe₂O₃?NaMn?Mn,Fe?₂?PO₄?₃ and the surface morphology by examining the raw materials by XRD,XRF and SEM.Sulfuric acid was selected as the leaching solution of tungsten smelting slag.Most of the calcium was enriched and retained in the filter residue.The leaching amount of iron and manganese in the 10 g tungsten smelting slag reached 2.1 g and 0.58 g.The reaction temperature,solid-liquid ratio,sulfuric acid mass fraction and time as the leaching reaction were investigated to influence with iron and manganese leaching,through the orthogonal test table to obtain the best process conditions:reaction temperature 80°C,solid-liquid ratio of1:6?g/g?,mass fraction of 25%?g/g?and reaction time is 90 min.leaching times is only one,One leach liquor cycles leaching once can increase the concentration of iron and manganese 3.045 g and 0.8325 g.?2?Neutralization and removal of iron:The set-up test simulated the oxidation of divalent iron ions by hydrogen peroxide.The effects of the amount of hydrogen peroxide added,the reaction time and the reaction temperature on the test were examined.The best conditions were obtained:the dosage was 1.1 times of the theoretical ferrous ion,the reaction time was 10 minutes,the reaction temperature was 20°C and the removal rate of ferrous ions reached 99.6%.Three substances,NaHCO₃,MnCO₃ and NaOH were selected to adjust the pH to remove iron.The best reaction was obtained at room temperature.The pH was first adjusted by using manganese carbonate.The retention rate of manganese was 97.83%,iron removal rate has reached about99.9%,and then adjust the pH to 5 using Na OH adjustment solution to remove other impurities,at this time manganese retention rate of 87.16%.?3?Calcium removal by fluoriding agent:In consideration of comprehensive considerations,calcium fluoride was used to remove calcium.The effects of temperature,reaction pH,time and amount of manganese fluoride on manganese removal were exa mined.The optimal conditions were obtained:the reaction temperature was 80°C,the pH was equal to 5,the reaction time was90 min,and the amount of added manganese fluoride was 1.4 times the theoretical amount of calcium.Under the optimum process conditions,the removal rate of calcium can reach 96.4%.?4?Removal of heavy metal ions,potassium and sodium,and crystallization of manganese sulfate:Manganese sulfide is used as a removal agent for removing heavy metal ions.pH is 5 and a temperature of 80°C,sufficient amount of manganese sulfide is added for a sufficient time for reaction.The effect of removing heavy metal ions is obvious;using the characteristics of metal ions,using sodium carbonate as a carbonizing agent,manganese is precipitated at a concentration ratio of 1.1:1 and a temperature of 35°C.to remove potassium and sodium;and manganese sulfate is used 20°C is the characteristic that the solubility will reverse,Firstiy evaporated and concentrated and then the temperature is increased.Through ICP,infrared spectroscopy and SEM characterization,it has been demonstrated that the purity of the product has reached the battery-grade manganese sulfate requirements.