▎ 摘　　要

NOVELTY - Treating gold smelting wastewater by quality comprises (1) collecting and processing extraction waste water in acid waste water, pumping extraction waste water into micro-electrolysis packing catalytic oxidation reaction tank, and entering comprehensive adjustment tank, (2) mixing impurity-removing waste water and reduction waste water in acid waste water with alkali liquid water in alkaline waste water, and recovering copper hydroxide precipitate from filter residue, (3) supplementing treatment of electrolyzed water in alkaline wastewater to concentrated brine produced by mechanical vapor recompression (MVR) system to feed liquid to increase chloride ion concentration in the electrolyzed water, and (4) deeply concentrating brine mixed in comprehensive regulating tank by electrodialysis system, returning fresh water to production system, and using desalinated water as supplementary water for alkali solution absorption liquid or supplementary water for other production sections. USE - The method is useful for treating gold smelting wastewater by quality. ADVANTAGE - The method has low waste water treatment cost and high water circulation utilization rate. DETAILED DESCRIPTION - Treating gold smelting wastewater by quality comprises (1) separately collecting and processing the extraction waste water in the acid waste water, pumping the extraction waste water into the micro-electrolysis packing catalytic oxidation reaction tank, adopting the micro-electrolysis catalytic oxidation technology, controlling the flow rate under the condition of aeration, adjusting the reaction residence time, where the chemical oxygen demand (COD) after treatment is 20-40 mg/l, entering the comprehensive adjustment tank, where the pH of the extraction wastewater is 2.5-4.5, the microelectrolytic filler is diatomite-based iron-carbon composite material, the mass ratio of silica is 15-30%, the mass ratio of iron is 30-60%, and the mass ratio of carbon is 10-55%, and preparing the micro-electrolytic filler by calcining for 2-4 hours in reducing atmosphere at temperature of 1000-1500degrees Celsius, where the specific surface area of the prepared filler is 500-1000 g/m2, the aeration conditions are that the aeration intensity is 2-10m3/m2/hours, and the electrolysis residence time is 2-10 hours, (2) mixing the impurity-removing waste water and the reduction waste water in the acid waste water with the alkali liquid water in the alkaline waste water, controlling the acid-base neutralization reaction point by adjusting the flow rate of the valve opening through the linkage of the intelligent pH sensor, where the pH of the mixed solution is between 7.5 and 8.5, filtering the mixed solution by plate and frame, recovering the copper hydroxide precipitate from the filter residue, where the copper ion concentration of the filtrate is lower than 0.5 mg/l, and entering the filtrate by comprehensive adjustment tank, (3) supplementing the treatment of the electrolyzed water in the alkaline wastewater to the concentrated brine produced by the mechanical vapor recompression (MVR) system to the feed liquid to increase the chloride ion concentration in the electrolyzed water, removing cyanide and ammonia nitrogen in the electrocatalytic oxidation reaction tank by electrochemical oxidation treatment to make it meet the emission standard, pumping into the comprehensive adjustment tank after buffering in the buffer tank, where the amount of the supplemented MVR concentrated brine is 10-30% of the volume of the electrolyzed water, the electrocatalytic oxidation reaction tank comprises power source, pole plate and electrolytic cell, the anode and cathode of the electrolytic cell are plate shape or porous mesh, the anode material of the electrolytic cell is titanium-based anode, and the anode coating is mixture of graphene, ruthenium and iridium, comprising 5-10% graphene, 50-75% ruthenium and 15-25% percent iridium, and the coating thickness is 1.5-10 microm, the electrolytic cell cathode is stainless steel cathode, and carrying out electrolysis under stirring, where the working current density of electrolysis is 100-1000 A/m2, the temperature of the electrolysis system is 40-80degrees Celsius, the electrolysis residence time is 2-8 hours, the total cyanide concentration in the feed liquid is lower than 0.5 mg/l after electrocatalytic oxidation treatment, and the ammonia nitrogen concentration is lower than 5 mg/l, and (4) deeply concentrating the brine mixed in the comprehensive regulating tank by the electrodialysis system, where the concentrated water enters the MVR system for evaporation and crystallization, returning the fresh water to the production system, where the amount of water entering the MVR system is 40-70% lower than that of the direct MVR evaporation process, the content of heavy metals in the solid salt of the mixture of evaporated sodium chloride, sodium sulfate and sodium nitrate is low, using the solid salt in snow melting agent, leather processing and dyeing and finishing industries, where the volume ratio of the feed desalination chamber and the concentration chamber of the electrodialysis is 1.5-2.5:1, the conductivity of the desalination chamber is controlled at 15-55 ms/cm after electrodialysis treatment, controlling the recovery rate of the desalination chamber at 30-60%, and using the desalinated water as the supplementary water for the alkali solution absorption liquid or the supplementary water for other production sections, where the heavy metal content of the mixed salt obtained after MVR evaporation is less than 0.01%.