Recovery of manganese values

Claim 1

In a process for the recovery of manganese values from a manganese bearing source, the steps of: a. forming a mixture of said manganese bearing source, sulfuric acid and a reductant comprising a chromium-containing compound in a weight ratio of from about 1:1:1 to about 2:1:10 manganese bearing source, chromium-containing compound and sulfuric acid, respectively; b. roasting said mixture at a temperature of from about 200° to about 500° C. for a sufficient time to remove the major portion of its water content and excess sulfuric acid; c. leaching the resultant pulp with water at a temperature of from about 25° to about 95° C; d. filtering the leach solution to separate undissolved solids from pregnant leach liquor containing dissolved manganese ions and chromium ions; e. selectively extracting the chromium ions from said pregnant leach liquor with an organic amine solvent; and f. precipitating manganese as solid manganese sulfate from the remaining leach liquor by subjecting the latter to a pressure of from about 50 to about 500 pounds per square inch at a temperature of from about 130° to about 250° C.