Reduction of parasitic water intake and selection of optimum concentrations for alumina production at Rusal Nikolaev LTD., Ukraine

In the environment of instable and constantly rising gas prices, energy expenses constitute 46 % of the prime cost of alumina of RUSAL Nikolaev Ltd. One of the reasons of increase of heat consumption and, accordingly, of the prime cost of the ?nished products is parasitic water intake at alumina production areas. A review of the situation created has allowed singling out the major issues in this trend: Dilution of aluminate liquor at the Thickening and Washing Area during ? occulant preparation for dosing into the thickeners. Utilization of technical water for water wash and mechanical seals of pump units at alumina production areas. Part of the water is pumped with drowned pumps to the process tanks and thickeners, reducing concentration of aluminate liquor. Dilution of aluminate liquor at the Precipitation Area during washing of ? ltering cloths of disk vacuum ?lters according to schedule. МАХ НТ consumption at the Evaporation Area is held per spent liquor cubic meters, accordingly at increase of parasitic water intake in aluminate and spent liquor, reagent dosage increases. Actions taken to reduce parasitic water intake and optimization of concentrations in alumina production have made it possible to save $3,07 M in 2014.