Domestic Saprolites as Potential Substitutes for Refractory-Grade Bauxite

摘要

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-micrometers-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. 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.