PROCESSING IRON- AND ZINC-CONTAINING SLUDGEs OF GALVANIC PRODUCTION
Researches on comprehensive recovery of heavy metals and their compounds from zinc- and iron-containing galvanic sludges have been carried out. Processes of extraction of zink and iron compounds from electroplating sludge of LLC “Signal-Nedvizhimost” and PLC “Robert Bosch Saratov” (the city of Engels) have been studied. The work aims at determining optimal parameters of extraction and further use of substances as secondary resourses to obtain pigments and oil paints based on them. The research results proved the compliance between the properties of the obtained oxides and pigments-extenders which are traditionally used in industry (kaoline, chalk, mica etc.) The possibility of using these products in production technologies of pigments-extenders for paints has been found. It is determined that it is cost effective to produce zinc white paint based on pigment-extender ZnO (extracted from galvanic sludge of LLC “Signal-Nedvizhimost”) which price was comparable with the market price of commercial paint KVIL. This fact may enable a company to get an annual income of about 700 thousand rubles, if they sell it. The bioassay (Chlorella Chlorella vulgaris Beijer) and calculation method proved that the recovery of heavy metals allows reducing the hazard galvanochemical class from the 2nd to the 4th one.