67 results about "Polyhalite" patented technology

The invention provides a method for preparing potassium sulfate by using polyhalite. The method comprises the following steps of: (1) grinding ores: grinding the polyhalite till 90wt% of the polyhalite are over 150 meshes in size; (2) washing: washing with water to remove the sodium chloride in the polyhalite; (3) roasting: roasting washed minerals at a high temperature; (4) leaching: leaching to extract potassium in the polyhalite; (5) solid-liquid separation: subjecting the ore pulp obtained through the leaching step to solid-liquid separation so as to obtain a mother liquor containing K+; (6) conversion: evaporating the mother liquor, adding potassium chloride and a potassium mixed salt, preparing potassium sulfate through the conversion method, and filtering to obtain a potassium sulfate product and the mother liquor; (7) evaporation: continuously evaporating the mother liquor, filtering to obtain a potassium mixed salt, and returning the potassium mixed salt to the conversion process. According to the method, the potassium sulfate is prepared by using the polyhalite. The process is simple, wide in source of raw materials and low in cost, wherein the sodium chloride in the polyhalite can be effectively removed. Meanwhile, the leaching rate of K+ is high and the water consumption of leaching is reduced. The concentration of K+ in the leaching mother liquor is high, and the energy consumption of the subsequent evaporation and crystallization step is reduced. Obtained potassium sulfate products are high in purity.

A process for preparing potassium sulfate and potassium-magnesium fertilizer from polyhalite includes the following steps of 1, ore grinding, wherein polyhalite is subjected to ore grinding until the content of 120-mesh ground polyhalite is 85wt% or above; 2, washing, wherein sodium chloride in polyhalite is washed away with water; 3, roasting, wherein the washed ore is roasted at a high temperature; 4, leaching, wherein potassium and magnesium in polyhalite are leached; 5, solid-liquid separation, wherein ore pulp obtained through leaching is subjected to solid-liquid separation, and mother liquor containing potassium sulfate and magnesium sulfate can be obtained; 6, evaporation, wherein the mother liquor is evaporated to separate out potassium sulfate, filtering separation is carried out to obtain a potassium sulfate product, the mother liquor continues to be evaporated to a certain concentration, and filtering separation is carried out to obtain a potassium-magnesium fertilizer product. The process is simple, the raw material source is wide, and the cost is low; sodium chloride in polyhalite can be effectively removed, the K+ leaching rate is high, the water consumption for leaching is small, the K+ concentration in the leaching mother liquor is high, the energy consumption for evaporative crystallization at the later stage is lowered, the K+ utilization rate is high, and the product grade is high.