| Electrolytic manganese slag is the amounts of solid waste produced in the production of electrolytic manganese metal.The electrolytic manganese slag which contained a variety of harmful heavy metals and ammonia nitrogen material is commonly used to be landfilled or piled up directly,causing serious potential pollution to the environment with small slag.According to the characteristics of the electrolytic manganese slag,not only reducing the damage to the environment,but also recycling resource can be realized by washing and recycling the soluble manganese and ammonium sulfate.This paper gave a research about that:extracting soluble manganese and ammonium sulfate from electrolytic manganese slag in the washing-slag water,then recycling soluble manganese slag by method of precipitation and recycling ammonium sulfate by method of blow-off.In addition,this paper carried on the preliminary design and economic accounting of the process for recycling soluble manganese and ammonium sulfate washing-slag water,and determined the feasibility of the process.Mainly content of this paper include several aspects as following:In the washing electrolytic manganese slag experiment using the clear water for washing,the influences of different liquid-solid ratio and washing time on soluble manganese and ammonium sulfate wash-out ratio were researched.Results showed that under the condition of the liquid-solid ratio=5:1,and the washing time=30 min,soluble manganese can be washed out at a rate of 92.0%,and ammonium sulfate can be washed out at a rate of 90.9%.This paper has took lime as precipitant in the recycling soluble manganese from washing-slag water experimental study,and adding coagulant strengthening precipitation effect.The experimental study has investigated the influence of soluble manganese recovery rate on the lime dosage,reaction temperature,reaction time,concentration of coagulant PAM and PAS.On the basis of orthogonal experiment,using the single factor experiment to optimize the precipitation conditions showed that the reaction under the condition of atmospheric pressure,n(lime):n(soluble manganese)=1.8,the reaction time=60 min,coagulant concentration=15 mg/L,and coagulant aid concentration=0.2 mg/L,soluble manganese's recovery rate could get 95%or more.Besides manganese in the precipitation has reached 18%.The experimental study has discussed recycling ammonium sulfate process from washing-slag water using method of blow-off by orthogonal and single factor experiment respectively.Besides,the removal of ammonium sulfate has been investigated on the effects of pH,reaction temperature,the flow of gas and reaction time.Results showed that under the condition of pH=12,the reaction temperature=80?,reaction time=40 min and gas flow rate=100 L/h,ammonium sulfate can be washed out at a rate of 96.1%.What's more,this paper has carried on the preliminary design and economic accounting of the process that recycling soluble manganese and ammonium sulfate by concentrate and evaporation the washing-slag water and then has selected and calculated stirring device,filter device and evaporating device mainly.Results showed that if a complete set of recycling soluble manganese and ammonium sulfate by evaporation and concentrate the washing-slag water has been set according to the size of the annual output of 30000 t electrolytic manganese metal,the cost of investment for RMB 13.70 million of fixed assets can make the annual profit for RMB 3.934 million by recycling 1965 t of soluble manganese and 6147 t of ammonium sulfate(worthRMB 11.548 million totally)respectively.Therefore,the scheme for implementing industrialization is completely feasible. |
PDF Full Text Request