NIOSHTIC-2 Publications Search
Domestic Saprolites as Potential Substitutes for Refractory-grade Bauxite.
MISSING :10 pages
The Bureau of Mines evaluated the potential for production of substitute refractory-grade bauxite (rgb) from saprolites and gibbsitic sands of the southeastern United States. A statistical analysis of data from a reconnaissance sampling program indicates that the discovery potential for saprolites high in gibbsite in the Alabama Piedmont physiographic province is not encouraging. Furthermore, the minus 12-um mineral concentrates produced from these saprolites and from gibbsitic sands of the coastal plain province were impure, contained insufficient alumina, and had poor refractory properties. A saprolite sample from the valley and ridge physiographic province was beneficiated by attrition scrubbing- hydrocycloning-wet high intensity magnetic separation to provide a concentrate containing about 70 pct al2o3 with a pyrometric cone equivalent (pce) of 35 to 36. Such material may be useful as a substitute for domestic 70-pct-alumina bauxite based on the pce values. More complete ceramic testing will be necessary to confirm this tentative conclusion. Recovery of only about 10 pct of the original saprolite weight as a high-gibbsite concentrate indicates that the proposed production method would be expensive compared with production costs in Guyana or China, the principal suppliers to the United States. The tonnage of saprolite suitable for production of a high-alumina substitute is still unknown.
IH; Report of Investigations
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division