Study On The Optimization Of Liquid Injection And The Distribution Of Ammonium Residue In Weathering Crust

The problem of Geo-environmental in mine is the focus of the current society.The control of the source control and the tailings governance are the keys to the management of the Geo-environmental in rare earth mines.Therefore,it is of great significance to study the amount of ammonium sulfate leaching agent,the injection method and the residual condition of ammonium sulfate in tailings.In this paper,the relationship between the extraction rate of rare earth ions and the amount of ammonium sulfate leaching agent is established based on the theory of chemical equilibrium.Aiming for weathered crust elution-deposied rare earth ore in Pingnan,Fujian province.Trough 3 indoor columns leaching experiment,under the condition of setting leaching efficiency,according to the calculation unit consumption to experiment and compare the error between practical leaching efficiency and assume leaching efficiency;And the optimal injection method of ammonium sulfate was determined by the indoor column leaching experiment;Finally ammonium residual distribution experiments,according to the seepage process ammonium sulfate ore leaching and ion exchange process,together with 3 indoor column leaching soak washing experiment and three groups of column leaching experiment,determine ammonium leaching ore after the occurrence position of mineral soil,storage,the amount of water required for washing and the time for washing.Research results show that:(1)Deducing the relationship between the leaching efficiency of the ore type and the dosage of the leaching agent.Trough indoor column leaching experiment for the above mineral soil,under the condition of setting leaching efficiency,according to the calculation unit consumption to experiment and compare the error between practical leaching efficiency and assume leaching efficiency,the maximum relative error is 4.33 %,less than 5 %.It is proved that the method of calculating the amount of leaching agent is more accurate.Therefore,this mathematical model can accurately control the amount of leaching agent and reduce the ammonia nitrogen pollution from the source.(2)It is determined that the concentration of ammonium sulfate leaching agent from 30 g/L to 10 g/L is the preferred solution in the condition of the same amount of leaching agent through the indoor column leaching experiment.The extraction rate of rare earth ions in step concentration is 92.94 %.The amount of ammonium sulfate was 6.72 % less than that of single concentration,and the amount of ammonium in the mine was 41.42 %,which was obviously lower than that of single concentration.(3)Ammonium residue distribution test was found that the residual positions of ammonium include the immobilization solution residual ammonium,the exchange of rare earth ions and the unsaturated adsorption of ammonium in the process of leaching.Ammonium ions residue amount of 0.173 mg/g ~ 0.388 mg/g(average 0.305 mg/g),including fixed ammonium liquid residue 12.4 % ~ 33 % of total residues(average 20.4 %),ammonium ion exchange accounts for 19.4 % ~ 31.2 % of total residue(average 22.2 %),not saturated ammonium adsorption of residue in 46.9 % ~ 66.3 %(average 57.4 %).According to the results of column leaching experiment,when the concentration of rare earth ions leaching liquid in low to 0.1 g/L,after 2.7 times add mine to the top of the soil pore volume of water(75 h)can make the ore leaching solution ammonium residual concentration is lower than the national standard of 15 mg/L.