The U.S. Bureau of Mines investigated a hydrochloric (hcl)-calcium fluoride (caf2) leaching procedure to treat domestic manganese (mn)- bearing silicate resources. The proposed process is an alternative to high-temperature and energy-intensive extractive techniques. Single-stage leaching with a stoichiometric amount of hcl and an f- mn mole ratio of 0.2 Extracted 96 pct of the mn when the leach conditions were 50 deg c, 3 h, and 35 pct solids. Ninety-eight percent of the mn was extracted during countercurrent leaching at similar conditions. A process flowsheet was developed that incorporated hcl-caf2 leaching, excess leach acid utilization, fluoride (f) recycle, and mn recovery. When the domestic manganese silicate ore was processed, 98 pct of the mn was extracted, 99 pct of the caf2 was reclaimed, and a leach residue was produced that passed the Environmental Protection Agency (EPA) extraction procedure (ep) test for nonhazardous waste.