INVESTIGATION AND DEVELOPMENT OF PROCESS OF PRODUCTION OF ALUMINA FROM HIGH CARBONATE CONTENT BAUXITES

The behaviour of all carbonate-containing minerals contained in bauxites has been studied at interaction with alkali-aluminate solutions used in alumina production at temperature 22 to 85 degrees C. The stability fields of carbonate minerals of bauxites in alumina production alkali systems have been determined, and recommendations concerning their removal at a stage of wet bauxite grinding have been given. A mechanism of going carbon dioxide from carbonates which are a part of bauxites, to an alkali-aliminate solution has been suggested, and a phase composition of the reaction products depending on the treatment conditions has been found out. Mechanisms of phase transformations of basic minerals of high-carbonate bauxites, i.e. gibbsite, kaolinite, hematite, siderite and its solid solutions at low-temperature roasting in various atmospheres have been determined. An energy-saving process of the low-temperature roasting sideritized bauxites has been devised. The results obtained have been recommended to be applied at alumina production plantsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio