Technical Research On Filter Press Washing Of All Slime Cyanidation Residue

In the production of gold,cyanidation is the dominant method in the field of gold production.However,in the production process of cyanidation,a large number of tailings will be produced.This kind of tailings is called cyanidation residue because of the residual cyanide.The all slime cyanidation slag is mainly the cyanidation slag produced by the all slime cyanidation carbon slurry method for gold extraction from oxidized ore.because the all slime cyanidation carbon slurry method is the most widely used gold extraction method,a large number of all slime cyanidation slag is produced every year.This topic is mainly to explore the pressure filtration washing integrated treatment process of all slime cyanidation tailing pulp,so that the washed tailing can meet the standard of stacking to tailing pond,while reducing the water content as much as possible,explore the minimum washing ratio,and achieve the goal of economic and energy saving.In order to find out the best leaching conditions,the horizontal oscillation leaching was carried out for the factory sample,the pressure filtration test and the washing tail residue..The results show that the extraction time is 20 hours,the leaching temperature is 25℃ the oscillation speed is 200 R·min-1,the pH of the extraction solution is guaranteed to be basic,The mass of the leach solution is 10 times of that of the sample solid,and the leach efficiency of the three kinds of all slime cyanidation tailings is over 84%.Mixing slurry with tail slag and tap water,the pressure filtration process was analyzed by Ruth’s constant pressure equation.The results show that the cake formed by the residue belongs to easy filtration and medium compression cake,it is suitable for solid-liquid separation by pressure filtration,The effect of pressure filtration is better when the slurry concentration is 30%.Change of filtration speed and water content of tailing pulp under different filtration pressure was studied by mixing tailing slag and lean liquid,the results show that the water content of tailing pulp with 30%slurry can be reduced to 15.30%at the pressure of 0.3 MPa for 120 s,dehydration for 7 min.The time range of penetration stage,displacement stage and evaporation stage is determined.After pressure filtration of tailings slurry at 0.3MPa,the cyanide concentration of tailings leaching solution is 35.04 mg·L-1,which is high and needs washing treatment.When the washing ratio was 9,the cyanogen in the extraction solution could be reduced to 4.97 mg·L-1,the pH of the washing solution had no effect on the washing;When washing by displacement,the temperature of washing water has no effect on the washing effect.The minimum washing ratio can be reduced to 1.85,and the cyanogen concentration of the washed cake extract can be reduced to 4.949 mg·L-1,It meets the stacking standard of cyaniding slag(<5.0 mg·L-1).The range of washing ratio of displacement stage,intermediate stage and diffusion stage was determined.