Removal of carbonate and oxalate pollutants in the Bayer process using thermal and chemical techniques

摘要: Abstract In the Bayer process, diasporic bauxite is dissolved in a caustic soda solution presence of lime at high temperature. During this concentration carbonate and oxalate gradually increases causing problems alumina refining process. work, removal efficiency pollutants from sodium aluminate has been increased using thermal chemical techniques. The pollution reduced by heating removing applying method. Bauxite leads to organic compounds carbonates magnesite calcite minerals exit as CO2, preventing addition these substances into solution. method soluble liquor, barium with structures Ba2Al2O5, Ba2Al4(OH)16 BaAl2O4, calcium (Ca3Al2(OH)12) phosphate (Na3PO4)–lime were separately used. As result, sedimented or oxalate, apatite. results also showed that was retrieved hydroxide. Investigating effect temperature, time, soda, Al2O3 revealed methods are most efficient technique remove respectively.