Method of granulating compost for the formulation of fertilizers. In one embodiment, the compost is ground to dust and pan granulated. A variety of ancillary materials may be incorporated into the compost mix for a wide range of possible applications. An embodiment is provided where agricultural seeds may be encapsulated in compost to enhance the quality of seed and reduce wastage during planting.

Compost granulation method

A method of wet granulation of fertilizer and other materials into granules. The method involves formation of the granule directly on the pan from the feedstock without intermediate steps or the use of seed materials. The result is a product having a completely uniform cross section. The feedstock is initially in the size distribution of −150 mesh with 90% or greater in the size range of 200 mesh. Moisture is maintained to facilitate a steady process without cycling.

Wet granulation method for generating granules

Granulated particles by making use an initial feedstock having particle size of −150 mesh and 90% or greater particle size of 200 mesh. The feedstock may be contacted in a pan granulator which includes a minor amount of nucleating material of about −35 mesh. Binder is introduced into the pan granulator to progressively layer the feedstock material onto the nucleating to form a final granular fertilizer or other product in any desired size distribution. The method by which the granules are formed is interruptible and is particularly useful for forming granules having a plurality of layers of differing material. The granules, by formation with dust feedstock and in the absence of seed material, lack a core and therefore include the maximum amount of tightly packed feedstock. This results in substantial increases in the break strength of the granules with uniform homogeneous cross-sections. Such granules overcome the limitations associated with existing granules to provide an industrially valuable product.

Granulation method and apparatus therefor

Methods of forming potassium sulfate include calcining polyhalite ore particles to convert the polyhalite ore particles to a water soluble composition. At least a portion of the water soluble composition is dissolved in an aqueous medium to form an aqueous solution comprising K+, Mg2+, and SO4 2- ions and a calcium containing solid. The calcium containing solid is separated from the aqueous solution to form a filtrate comprising K+, Mg2+, and SO4 2 ions. A potassium containing salt is dissolved in the filtrate to increase the concentration of K+ and SO4 2- ions to form a concentrated liquor, and K2SO4 is crystallized from the concentrated liquor. A system for processing polyhalite ore includes a countercurrent leaching apparatus, a first mix tank, an evaporator, and at least one crystallizer.

Methods of processing polyhalite ore methods of producing potassium sulfate and related systems

A process for producing potassium sulfate, sodium sulfate, and sodium chloride from potash and a sodium sulfate/water source, wherein potash (12), sodium sulfate (14), slurry (34) from the recovery stage and brine (18) from the gaserite decomposition stage (20) are introduced to a first stage (10), wherein the sodium sulfate and potash dissolve, such that glaserite is precipitated. The slurry is concentrated and delivered (22) to the glaserite decomposition stage (20) along with water (24). Potash is introduced directly (8) and/or via stream (22) by introducing excess potash into stage (10). The potassium sulfate solids are separated, washed and dried to give a potassium sulfate product (27). The mother liquor (18) removed from the reactor is returned to the glaserite production stage (10). The brine (26) produced in the production of glaserite (10) is evaporated in an evaporative crystallizer (28). The removal of water (30) produces a supersaturation of sodium chloride, which precipitates out of solution.

Co-production of potassium sulfate, sodium sulfate and sodium chloride

A method of producing potassium sulfate consists in conversion of sodium sulfate with potassium chloride in an aqueous medium to yield glaserite and a glaserite solution. Then, the glaserite is decomposed with potassium chloride in water to obtain potassium sulfate and a sulfate solution which is returned to the first stage of conversion. The glaserite solution is cooled at temperatures ranging from +3° to -8° C., whereby mirabilite and a chloride solution are formed, the latter being evaporated to obtain sodium chloride and a concentrated chloride solution. Finally, the concentrated chloride solution is mixed with mirabilite, and the resulting suspension is delivered to the first stage of conversion of sodium sulfate with potassium chloride. The proposed method permits producing high-quality potassium sulfate with full utilization of the return solutions. The yield of potassium sulfate reaches 98.6% at a K 2 O content of up to 53% by weight.

Method of producing potassium sulfate

A method of producing a complex mineral fertilizer is disclosed, comprising the steps of decomposing polyhalite at a temperature not exceeding 110° C. in the presence of dilute nitric acid, neutralizing the obtained suspension with a substance selected from the group consisting of calcium carbonate, calcium hydroxide and calcium oxide, and separating the resultant product.

Method of producing a complex mineral fertilizer

A procedure is disclosed for preparing nitrogen-potassium fertilizer residing in interaction of potassium hydrogen sulfate with calcium nitrate, barium nitrate or strontium nitrate in an aqueous medium, followed by treatment of the reaction mass with ammonia, separation of the resulting slightly soluble sulfate and isolation of the desired product.

Procedure for preparing nitrogen-potassium fertilizer

A method of producing magnesium sulphate comprises the steps of interacting ferrous sulphate with compounds including magnesium carbonates, oxides and hydroxides, with magnesium sulphate being produced. The step of interacting the starting reagents is conducted in water medium in the presence of carbon dioxide and is effected in the range of temperatures of 80° to 100° C.

Igor D. Sokolov

Papers

Method of producing potassium sulfate

Method of producing a complex mineral fertilizer

Procedure for preparing nitrogen-potassium fertilizer

Method of producing magnesium sulphate