The United States is more than 90 pct dependent on imported bauxite as a source for aluminum, but it has vast nonbauxitic aluminum resources, such as kaolinite, anorthosite, alunite, etc. As part of a program to devise processes for treating these resources, the Bureau of Mines investigated a bench-scale leaching process using hydrochloric acid (hcl) and fluoride to extract aluminum from Wyoming anorthosite. Hcl and fluoride-to-aluminum (f/al) mole ratios were studied with respect to aluminum extraction for single- stage, cocurrent, and countercurrent leaching modes. Using 95 pct stoichiometric hcl and a f/al mole ratio of 0.27, 90 pct of the aluminum was extracted by countercurrent leaching. Single-stage leaching with the same amount of acid and fluoride extracted 48 pct of the aluminum. Three fluoride sources, caf2, na2sif6, and h2sif6, were used and gave similar results on aluminum extractions.