Reduction of High-Chromium-Containing Wastewater in the Leaching of Pyritic Waste Rocks from Coal Mines

Coal is an abundant resource which can be used to produce low-cost energy; however, its usage causes great environmental damage. Before mineral coal used, it must processed remove tailings. These tailings contain pyrite and accumulate in large dumps, presenting significant liabilities, such as acid mine drainage. Another industry that generates liabilities the chrome-plating industry, mainly because produces hexavalent chromium (Cr6+) waste. The main aim of this work was evaluate Cr6+ a reduction agent trivalent (Cr3+) conversion leaching coal-mine waste containing pyrite. Cr3+ about 100 times less toxic than easily removed from industrial effluents by alkaline precipitation. There are several sources Cr6+—a compound known worldwide toxic, carcinogenic, mutagenic. A treatment device developed tested for treatment. results indicated system reduced 100% through wastewater sample electroplating industry. In addition, sludge resulting process, after calcination, ceramic glaze pigment and, when compared with pigment, showed similar mineralogical characteristics.