Method of producing potassium sulfate
AssigneesAristos Capital Corporation, Airborne Industrial Minerals Inc.
InventorRobin Phinney
Life of this patent
Estimating the term…
Abstract
A process is provided for producing potassium sulfate by reacting ammonium sulfate and potassium chloride at a temperature of about 30 to 40° C. to produce a slurry containing K2SO4·NH4·2SO4 double salt, and reacting this double salt with an aqueous solution containing potassium chloride at a temperature of about 30° C. to produce a slurry containing potassium sulfate. The slurry containing potassium sulfate is subjected to a solids/liquid separation step to obtain potassium sulfate crystals having a size in the range of about 20 mesh to about 150 mesh.
Claims8
A method for producing potassium sulfate from a source containing ammonium sulfate, comprising:
- reacting potassium chloride and ammonium sulfate in a mixer (42) at a temperature between 30 and 40° C. to produce a slurry containing potassium sulfate and ammonium sulfate;
- passing the slurry containing potassium sulfate and ammonium sulfate through a solids/liquid separator (44) to obtain a filtrate and solids comprising potassium sulfate;
- reacting said solids comprising potassium sulfate with a solution of potassium chloride in a mixer (46) to produce a slurry containing potassium sulfate;
- passing the slurry containing potassium sulfate through a solids/liquid separator (48) to obtain a filtrate and potassium sulfate crystals;
- recycling the filtrate from solids/liquid separator (48) back to the mixer (42);
- passing the filtrate from solids/liquid separator (44) to settler (16), where this filtrate is separated into fines, which are recycled back to mixer (42), and an overflow liquor;
- reacting said overflow liquor with sodium sulfate and either calcium chloride or calcium sulfate dihydrate in mixer (50) at a temperature of 30° C. to produce a slurry containing syngenite, CaSO4·K2SO4·xH2O, and
- passing the slurry containing syngenite into a solids/liquid separator (52) to produce a filtrate and solid syngenite.
A method for producing potassium sulfate from a source containing ammonium sulfate, comprising the steps:
- reacting potassium chloride and ammonium sulfate in a mixer (14) at a temperature of less than 30° C. to generate a slurry of K2SO4·(NH4)·2SO4 double salt;
- passing said slurry through a solids/liquid separator (16) to obtain a filtrate and solid double salt;
- reacting said filtrate and potassium chloride in a mixer (18) to generate a slurry;
- passing the slurry from mixer (18) through a solids/liquid separator (20) to obtain a filtrate containing ammonium chloride;
- potassium chloride and sodium chloride and solid double salt;
- reacting the solid double salt from solids/liquid separator (16) and from solids/liquid separator (20) with potassium chloride in a mixer (22) to produce a product;
- passing said product through a solids/liquid separator (24) to obtain a filtrate, which is recycled back into mixer (18) and solid potassium sulfate;
- reacting said filtrate containing ammonium chloride;
- potassium chloride and sodium chloride with a solution of calcium chloride and solid sodium sulfate in a mixer (26) at a temperature that is less than 70° C. to generate a slurry of syngenite (CaSO4·K2SO4·xH2O);
- passing the syngenite slurry through a solids/liquid separator (28) to obtain a filtrate and solid syngenite;
- reacting the filtrate from solids/liquid separator (28) with a solution of about 23.6% ammonium chloride and lime or hydrated lime in a mixer (30) at a temperature of about 80° C. to produce ammonia and a liquid containing residual ammonium values;
- reacting the solid syngenite with ammonium bicarbonate in a mixer (36) at a temperature of about 70° C. to produce a slurry containing calcium carbonate, potassium sulfate and ammonium sulfate, and
- passing the slurry containing calcium carbonate, potassium sulfate and ammonium sulfate into a solids/liquid separator (33) to obtain solid calcium carbonate and a filtrate containing potassium sulfate and ammonium sulfate.
Dependencies are inferred from the claim text.