Study On Washing And Comprehensive Recovery Of Cyanide Tailings

Cyanide-containing tailings(liquid)will be produced in the process of wet gold extraction,but the wet process is one of the main methods used by domestic and foreign enterprises,therefore,the treatment of cyanide-containing waste residue(liquid)has become an important factor in the wide application of wet-process gold extraction process.The latest National list of Hazardous wastes defines "cyanide tailings" as hazardous wastes.The Environmental Protection tax Law of the people's Republic of China will impose an environmental protection tax of 1000 yuan per ton on hazardous waste.At the same time,the compilation of the Technical Specification for pollution Control of cyanide waste residue in Gold Industry has also been included in the 13th Five-Year Plan of the National Environmental Protection Standard.It can be seen that the management of cyanide residue(liquid)will become more and more strict in the country.On the basis of practical application,the comprehensive purification method of cyanide-containing tailings(liquid)was studied in this paper,and the chemical pure reagent and different cyanide-containing tailings(liquid)were used as simulative experimental materials at the same time.By changing the washing times of tailings,the ratio of liquid to solid,PH value and oxidation reagent,the change trend of relative indexes in the purification process of cyanide-containing tailings(liquid)is grasped,and the actual control effect of production is combined.The best index of removing cyanide was screened out,and the residue(liquid)containing cyanide was treated,which changed from hazardous waste to general solid waste,so as to reduce the pollution of waste to the environment and reduce the pressure of environmental protection in enterprises.Through the simulation experiment,the following relevant information is obtained:The changes of washing times,pH value of liquid-solid pH ase ratio and oxidation reagent have great influence on the comprehensive purification of cyanide-containing residue(liquid)by "pressure-washing-decomposition" process.And there is the best index interval.The cyanide content of cyanide-containing residue(liquid)can be effectively reduced by using the process of "pressure filtration,washing and decomposition" to remove cyanide from the residue(liquid).The gold cyanide tailings were treated innocuously according to the leaching toxicity Identification Standard of Hazardous wastes(GB5085.3-2007)and reached the general solid waste identification standard.