Process for beneficiating oil-shale

摘要

Disclosed is a process for beneficiating oil-shale wherein the oil-shale is treated in a first stage with an aqueous ammonium salt solution and in a second stage and optionally a third stage in the presence of a solution containing ammonium ions/ammonia, or both. The pH of the first stage is from about 5 to 9, and the pH of the second and third stages are from about 0.5 to 5 or about 9 to 12 with the proviso that the pH of the second and third stage is not in the same range.