The problem of processing slimes of galvanic production, formed as a result of neutralization of technological solutions and wastewater containing heavy non-ferrous metals is considered. At present, sludges are transported to disposal area and are not used in any way. Typically, such sludges contain significant amounts of chromium and nickel, which creates environmental hazard. Investigated sludge of Dimitrovgrad Automobile Units Plant (Russia) contains up to 6.6% Ni and up to 7,4% Cr. The hydrometallurgical process is proposed to treatment of these sludges. Solutions of sulfuric acid, ammoniaс chloride and Trilon B were used as lixiviants. It is shown that when using a solution of sulfuric acid with pH=1,5, extraction of up to 93,3% Cu, 70,2 Ni, 90,3 Zn is achieved.

The process of sorption-electrochemical cleaning of rinse waters, obtained after ammonia etching of printed circuit boards from copper ions, is proposed. Cation exchanger KU-2×8 and ampholyte Lewatit MonoPlus TP 207 for the extraction of copper were tested. Capacity up to breakthrough of Lewatit MonoPlus TP 207 is 0.11 g/g and a full dynamic exchange capacity for copper of 0.15 g/g. Various options of a pregnant ion exchanger desorption are considered. The best stripping ability has a 20% solution of sulfuric acid. The possibility of desorption by a partially de-coppered eluate was studied. This scheme allows the use of acid formed in the process of copper electro-winning. The effect of concentrations of NH4Cl and NH4OH on the sorption of copper was studied. It was shown that, with an increase in the concentration of NH4Cl to 100 g/dm3, the capacity of the ion exchanger decreases by 10.42%. Thus, the ion exchanger Lewatit MonoPlus TP 207 effectively absorbs copper even at high salt background. A combined sorption-electrochemical technology has been proposed for treatment of rinse waters. The proposed technology will reduce consumption of fresh water and ammonia for printed circuit boards washing and extract copper in the form of elemental metal.

The object of the study is salt concentrates formed as a result of treatment of concentrated acidic and alkaline wastewater of galvanic processes, realized on Ural Optical & Mechanical Plant (Russia). Salt concentrates are to be disposed of as low-hazard substances, but periodically the presence of nickel ions in them was detected. Concentration of nickel ions reaches up to 0.3 g/L, the total salt content reaches 200 g/L. The possibility of sorption purification of salt concentrates from nickel on the aminocarboxylicionite Lewatit TP 207 was studied, and the capacitance characteristics of the ionite were determined. It is shown that a high salt background does not reduce the ion exchange capacity of ionite for nickel. The dynamic capacity of Lewatit TP 207 before the breakthrough was 0.155 g/g. Nickel desorption is carried out with 20% sulfuric acid. The maximum concentration of nickel in the eluates was 25.484 g/L. Such eluates can be returned to the nickel-plating bath. The technology of periodic ion-exchange purification of salt concentrates is proposed.

The use of hydrogen peroxide and hydrazine sulfate for the treatment of chrome-containing rinsing waters of galvanic production of machine-building enterprises is proposed. The process of reducing chromium (6+) to (3+) from rinsing waters with a concentration of 8.55 mg/dm3 was studied. These reagents allow reducing more than 99% of chromium (6+) to chromium (3+) and maintaining a low salt content of treated wastewater. The consumption of hydrogen peroxide is 1.5 mg/dm3, and the consumption of hydrazine sulfate is 10 mg/dm3. The current situation in the treatment of galvanic wastewater leads to pollution of the environment with dangerous substances (CN-, Cr6+, F-, Cd2+), irrational use of raw materials and significant economic losses. The possibility of extracting valuable components from wastewater, in order to recycle them and return the treated water to production, is considered. Hydrogen peroxide is effective for treating acidic wastewater, and hydrazine sulfate can be used for both acidic and alkaline wastewater. Removal of excess hydrogen peroxide from the solution after reduction of chromium (6+) before precipitation of chromium (3+) hydroxide is required. The toxicity of hydrazine compounds must be taken into account.

The problem of processing galvanic sludges, formed as a result of neutralization of technological solutions and wastewater containing heavy non-ferrous metals is considered in this study. At present, sludges are transported to disposal area and are not used in any way. Typically, such sludges contain significant amounts of chromium and nickel, which creates environmental hazard. Investigated sludge contains up to 6,6% Ni and up to 7,4% Cr. The hydrometallurgical process to treatment of these sludges is carried out. Solutions of sulfuric acid and ammonia were used as lixiviants. It is shown that when using a solution of sulfuric acid with pH=1,5, extraction of up to 93,3% Cu, 70,2 Ni, 90,3 Zn is achieved. For selective nickel recovery sorption concentration by Lewatit TP207 is proposed. Keywords: Galvanic sludge, hydrometallurgy leaching, nickel, ion-exchange resin