Study On The Basic Characteristics Of Electrolytic Manganese Slag From Songtao River Basin And Its Harmless Resource Utilization Approach

Manganese is widely used in chemical industry,iron and steel,non-ferrous metals,electronics,aerospace,agriculture and other important industrial fields,is an important industrial raw materials and strategic resources of the national economy.While electrolytic manganese enterprises produce manganese products in large quantities to create economic benefits,a large amount of electrolytic manganese slag discarded will cause different degrees of pollution to the ecological environment.This study selected county of electrolytic manganese slag as the research object,on the basis of analyzing the basic physical and chemical properties of electrolytic manganese slag and leaching toxicity,determines the characteristics of the contaminants pollutant,put forward by using water washing and the method of pyrolysis harmless,electrolytic manganese slag of electrolytic manganese slag cement,electrolytic manganese slag-calcium carbide slag,the electrolytic manganese slag-calcium carbide slag,red mud,electrolytic manganese slag,fly ash preparation glue cure body coordination,to explore the different ratio of electrolytic manganese residue glue cure effect and the influence of the leaching toxicity.In order to study the mechanism of solidification reaction,the mineral composition,chemical structure and surface morphology of the solidified body of different materials were compared and analyzed by combining XRD and SEM.The following conclusions are drawn:（1）electrolytic manganese slag electrolytic manganese slag main minerals are dihydrate gypsum（Ca SO₄·2H₂O）,quartz（Si O₂）,Al₂O₃and hematite（Fe₂O₃）,calcium sulfate（Ca SO₄）,the main chemical components include Si O_2,Al₂O₃,Fe₂O₃,Ca O,SO₃,Mn O.（2）Through the leaching toxicity test,the concentration of manganese,ammonia nitrogen and sulfate ranged from 28 to 1460 mg/L,0.986 to 792 mg/L,and 1060 to9700mg/L,respectively.The exceeding multiple of ammonia nitrogen in the leaching solution of the new slag was 23 to 32 times,and the exceeding multiple of Mn was as high as 470 to 730 times,and the content of sulfate was more than 1500mg/L.Its main characteristic pollutants are manganese ion(Mn²⁺),ammonia nitrogen（NH₄⁺-N）,sulfate(SO₄^2-).（3）In this study,it is considered that 1:2 solid-liquid comparison is appropriate,and there is little difference in pollutant dissolution concentration between 5min and180min washing time.The amount of manganese ions and ammonia nitrogen is getting less and less,and the removal efficiency of ammonia nitrogen in the first washing is the highest.The removal efficiency of ammonia nitrogen in the first washing is 84%,and that of manganese in the first washing is 91.7%.The concentration washing experiment results showed that the concentration washing effect of ammonia nitrogen,the main pollutant of electrolytic manganese slag,was better,which was conducive to the crystallization recovery and resource utilization of ammonium sulfate detergent.When the manganese washing was concentrated to 1.2g/100g,the washing efficiency was reduced,and it was suggested to control the washing at 7 times.（4）In the pyrolysis analysis and thermogravimetric analysis of manganese slag,at 100～200℃,the manganese slag is free water dehydration weightlessness;At300～400℃,the crystal water of dihydrate gypsum is removed for weightlessness;400～800℃,for ammonium sulfate decomposition weight loss,dihydrate gypsum,ammonium sulfate further decomposition.（5）The optimal level of each factor in the orthogonal experiment of electrolytic manganese slag-cement was 15%cement and 20%sand and gravel.The water toxicity of the test block is lower than the experimental results and lower than the groundwater quality standard（GBT14848-2017）Ⅰstandard.Considering the factors of cost and strength,the optimal ratio of electrolytic manganese slag to calcium carbide slag in the gel solidification test is formula 4（Electrolytic manganese slag:85%;Calcium carbide slag:15%）.Under the synergistic effect of fly ash and electrolytic manganese slag,when the mixing amount of electrolytic manganese slag and fly ash reaches 2:1,the properties of cementitious material can meet the performance requirements of 32.5#ordinary cement in national standard.Washing and pyrolysis can effectively solve the electrolytic manganese residue glue before cure deamination,suggested that the price of filter is easy to obtain,low alkali treatment,optimize the processing condition,improve manganese slag effective removal of NH₄⁺-N,eliminate the maintenance stage NH₃release pollution,realize the security of underground filling,electrolytic manganese slag improve the electrolytic manganese slag content,increasing the amount given.It is an effective way to realize the gel solidification of electrolytic manganese slag to realize resource utilization.