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Historical ore exploitations generated mining waste with useful metal content, near Baia Mare, Romania. Central Flotation Pond (CFP) represents a secondary resource, but also a risk factor of pollution for the environment: groundwater, surface water, soil, air. CFP was inventoried by the Permanent Secretariat of the International Commission for the Protection of Danube River (ICPDR) as high risks spot in Romania with immediate effects on Somes-Tisa sub-basin, due to the content of dangerous substances: cyanide, he...

The hydrometallurgical process for obtaini ng alumina by Bayer process bauxite is getting significant amounts of red mud (0.8 - 2 t / t Al 2O3). It is deposited in dumps which can cause danger for environment mainly due to the alkali content ( pH = 8-13) and small dimensisons of particles (less than 60 microns). Chemical and mineralogical composition of red mud bauxite is closely related to type of the bauxite used as raw material and processing conditions determined by some peculiarities of applied technology (pr...

The bauxite is not processed through the usua l processes of ore en richment because of the mineralogical composition and structure, the intergrowths of minerals being very fine. Mineralogical characterization is very important to choose the method of extracting alumina from bauxite. This paper presents the mineralogical st udy of a hydrargyllitic bauxite from Sierra Leone and of the red mud resulted after extraction of alumina by Bayer method. The mineralogical characterization of red mud is needed to choose the ...