STUDIES ON METAL FLOW FROM KHONDALITE TO BAUXITE TO ALUMINA AND REJECTS FROM AN ALUMINA REFINERY, INDIA

摘要

Alumina is produced from khondalite hosted bauxite of Indianrnorigin in the Alumina refinery employing the time tested Bayer’srnProcess. In the process, about 40% of unwanted elements arernrejected as undigested sand and red mud. During the whole cycle;rnmajor, minor, trace and RE elements in these litho-units getrnredistributed, either depleted or enriched. Khondalite, the sourcernrock of bauxite, is rich in silica, moderate in alumina and ironrnwith minor titanium. Bauxite becomes rich in alumina and ironrnwith subordinate titanium and negligible silica. After aluminarnrecovery from bauxite, most of the valuable metals including REErnget accumulated in the refinery rejects. The studies, whilernestablishing the extent of various metals dispersed in khondalite,rnbauxite, undigested sand, red mud and alumina also reveals thernstate of enrichment of valuable metals in undigested sand andrnsuggests possible means to recover some of them.