Treatment Of Cyanide-containing Wastewater Using The Coal-based Adsorption Material As The Electrode

New coal-based electrode material made of low rank coal and direct coal liquefaction residue which in Sunjiacha of Yulin was used in electric adsorption treatment of gold cyanide wastewater as anode and cathode. Mainly for the high concentration of gold and zinc sulfate precipitation cyanide wastewater, studied the preparation conditions and the conditions of coal-based electricity adsorption process electrode material impact on the electrical adsorption process and technology parameters, as well as depth of the reaction mechanism.Studies have shown that under the conditions of carbonization temperature 800℃, HNO3 concentration 10%, activation time 16 h, the homemade adsorption capacity of coal-based electrode material is strongest effect electrical adsorption optimal. When the absorption voltage of 2v, adsorption time of 5h, plate spacing of 5mm, solution volume of 50 ml, the solution after precipitation of cupric ion, total cyanide, thiocyanate ion and zinc ion removal rate were 90.63%、71.49%、28.65% and 90.63%. While the absorption voltage 2v, adsorption time 24 h, plate spacing 10 mm, solution volume 50 ml, the high concentration of cyanide in gold extraction wastewater zinc, iron removal rates reached 99.52%、83.28%. But the cupric ion、thiocyanate and total cyanide ion removal rates are not so high, amazing its ion concentrations were reduced 2080.25mg/L、5738.50 mg/L and 3720.84 mg/L. Long time adsorption and replace the electrode sheet continuous adsorption experiments show that the removal rates of cupric ion, total cyanide and free cyanide, thiocyanate, zinc and iron were up to 99.91%、98.29%、63.40%、81.87%、100%、99.17%.Analysis of anode plate SEM-EDS, electrical adsorption process precipitate XRD and phenomena show that electric adsorption process can be divided into the three parts for directional migration of ions, enrichment precipitation and the anode adsorption. Under the influence of the electric field the metal cyanide complex ions, free cyanide and thiocyanate anions in solution generate directional movement, and the same time, anions gradually enriched to anodic make the concentration increased. Anodic oxidation reaction between oxygen precipitates and free cyanide, resulting in the local hydroxide ion concentration decreased, and the same time Enrichment of various ions near the anode take place complex precipitation reaction produce a large number of of copper thiocyanate and small amounts of Cu CN, white precipitate zinc cyanide or red-brown copper ferrocyanide. While free cyanide, thiocyanate and metal cyanide complex ions adsorbed on the surface of the anode, resulting in reduced concentration of various ions in solution, to achieve the purposes of comprehensive recovery.