3 results about "Polyhalite" patented technology

The invention provides a process for the preparation of polyhalite granules comprising the steps of providing an aqueous ammonium nitrate (AN) solution; heating the solution to produce a hot solution; adding the hot solution to polyhalite; and allowing the mixture to cool during a granulation process. The invention further provides a process for the preparation of polyhalite granules where polyhalite is granulated with ammonium nitrate to form potassium nitrate, calcium ammonium nitrate, ammonium nitrate and / or magnesium nitrate and ammonium sulphate and a polyhalite granule comprising polyhalite and potassium ammonium nitrate.

A method of manufacturing a fertilizer comprising biomass, consists in that the biomass comprising, in dry matter, simple and complex proteins in an amount from 8 to 30% by weight and phosphorus compounds in an amount from 1 to 3% by weight P2O5, is mixed with at least one carbonaceous raw material selected from the group comprising lignite, bark, sawdust, humus, compost, peat and straw in an amount of 5 to 20% by weight in relation to the biomass, is ground to a particle size of less than 5 mm to produce a pulp with a dry matter content from 10 to 70%, then the resulting pulp is mixed with at least one evaporite mineral selected from the group comprising polyhalite, calcite, dolomite, gypsum, anhydrite, carnallite, sylvite, barite, after which the whole is dehydrated to a dry matter content from 40 to 85%, then mixed with alkaline raw materials in an amount sufficient to control the temperature of the mixture in the range from 60 to 140ºC and obtain a moisture content of less than 30%, preferably 10 to 15%, and then the product obtained is granulated to obtain granules with sizes from 1 to 5 mm, and alkaline raw materials forming inorganic coatings are applied to the surface of the granules, after which a substance forming an outer coating is sprayed.

The invention belongs to the technical field of salt chemical industry, and particularly relates to a leaching mining method for potassium in polyhalite. A sodium chloride solution and pure water are used as leaching agents, efficient extraction of potassium resources is achieved through three-stage alternate leaching of induction, strengthening and stabilization, the sodium chloride solution is adopted at low pressure in the induction stage, the solubility of CaSO4 is reduced through the salting-out effect, deposition is inhibited, meanwhile, Na < + > is preferentially combined with Mg < 2 + > and SO4 < 2-> released by polyhalite to generate anhydrous natroedite, and the sodium chloride solution and the sodium chloride solution are separated out; the polyhalite is pushed to be dissolved, balanced and positively moved to realize rapid initial dissolution of potassium; in the strengthening stage, pure water is switched and pressure is increased in a gradient mode, permeation is enhanced, the leaching area is enlarged, the thermodynamic driving force of polyhalite dissolution is improved, and potassium dissolution is accelerated by means of the effects of low viscosity, high diffusivity and high pressure of the pure water; in the stable stage, high pressure is maintained, a low-concentration sodium chloride solution is adopted, calcium ion deposition and potassium ion reverse adsorption are inhibited, deep recovery of residual potassium is achieved, and therefore the leaching rate of potassium and the comprehensive benefits of the process are improved.