Assertion: potassium carbonate | /r/AtLocation | sufficient amount
Facets:
Source sentences:
text: A process for producing potassium carbonate which comprises admixing a double sulfate salt of potassium and magnesium containing less than about 2% sodium chloride by weight with carbonaceous material and a substance selected from the group consisting of magnesium oxide and potassium carbonate, comminuting the mixture and forming the mixture into pellets, heating the pellets at a temperature between about 725 and about 1000 C. until said double salt is substantially completely converted into a mixture of magnesium oxide, potassium sulfate, and potassium sulfide, cooling the reaction product in a non-oxidizing atmosphere, leaching the reaction product with an aqueous solution of potassium carbonate saturated with potassium sulfate, said potassium carbonate being in sufficient amount to inhibit solution of solid phase potassium sulfate whereby potassium sulfide is selectively dissolved therefrom, separating the leach liquor from the undissolved solids, treating said leach liquor with carbon dioxide to a pH between about 7.9 and about 8.5, whereby the potassium sulfide therein is converted into potassium carbon-ate and bicarbonate and potassium bicarbonate is precipitated therefrom, separating the precipitated potassium bicarbonate, concentrating the potassium bicarbonate mother liquor and recovering solids therefrom, calcining said solids in an oxidizing atmosphere to convert any intermediate sulfur compounds of potassium therein to potassium sulfate, commingling the calcined solids with water in a proportion suiiicient to dissolve all of the potassium carbonate therein but insufficient to dissolve all of the potassium sulfate, whereby an aqueous slurry is obtained comprising solid-phase potassium sulfate in an aqueous solution of potassium carbonate saturated with potassium sulfate, and recycling said aqueous slurry for leaching a further quantity of said reaction product obtained from said double sulfate salt of potassium and magnesium.