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CN-122010145-A - Method for producing anti-caking potassium nitrate

CN122010145ACN 122010145 ACN122010145 ACN 122010145ACN-122010145-A

Abstract

The application relates to the field of material science and engineering, and particularly discloses an anti-caking potassium nitrate production method, which takes high-purity potassium nitrate crystals as a base material, sodium dodecyl sulfate as an anti-caking agent, and the proportion of the sodium dodecyl sulfate is 10g to 100g per ton of the base material; the production process includes dissolving sodium dodecyl sulfate in pure water to prepare transparent modifying liquid, spreading the modifying liquid to wet the surface of crystal homogeneously, drying the wet material in non-sealed heating environment with the moisture eliminating channel to form stable hydrophobic film, and final twice mechanical mixing to form the product. The application ensures that the water insoluble matters and clarity of the product completely meet the analytical purity standard through the liquid phase micro-coating and specific temperature control and dehumidification process, simultaneously obviously reduces the hygroscopicity and caking tendency of the crystal, and effectively solves the problems of solution turbidity, excessive introduction of organic impurities and purity damage caused by the traditional physical anti-caking technology.

Inventors

  • XIAO QIFA
  • ZHANG DAJUN
  • LIU JIHUA

Assignees

  • 四川西陇科学有限公司

Dates

Publication Date
20260512
Application Date
20260312

Claims (10)

  1. 1. The anti-caking potassium nitrate is characterized by being prepared by mixing high-purity potassium nitrate crystals and sodium dodecyl sulfate, wherein the high-purity potassium nitrate crystals are used as base materials, the sodium dodecyl sulfate is an anti-caking agent, and the formula proportion of the anti-caking potassium nitrate is that 10g to 100g of sodium dodecyl sulfate are mixed per 1000kg of high-purity potassium nitrate crystals.
  2. 2. A process for the production of anti-caking potassium nitrate according to claim 1, comprising the steps of: s1, dissolving the sodium dodecyl sulfate with the formula amount into pure water to prepare an anti-caking modified liquid; s2, uniformly spraying the anti-caking modified liquid on the surface of the high-purity potassium nitrate crystal, and primarily mixing to obtain a wet mixed material; S3, placing the wet mixed material in a heating environment for dehumidifying and drying to evaporate water and form a hydrophobic film on the surface of the crystal to obtain a dried material; S4, secondary mixing is carried out on the dry materials, and then the anti-caking potassium nitrate is obtained.
  3. 3. The method for producing the anti-caking potassium nitrate according to claim 2, wherein the preparation method of the high-purity potassium nitrate crystal comprises the following steps: Dissolving industrial potassium nitrate in water, adding ammonium nitrate to react at 80-90 ℃ to remove nitrite; ammonium sulfide is then added to react at 80 ℃ to 90 ℃ to remove heavy metal ions; Sequentially adding potassium carbonate and potassium hydroxide and keeping a micro-boiling state to remove calcium and magnesium ions and ammonium radicals; Finally, zinc oxide and active carbon are added to remove excessive sulfide ions and organic impurities, and the filtered clear liquid is subjected to neutralization, concentration, crystallization and centrifugal separation to obtain the high-purity potassium nitrate crystal.
  4. 4. The method for producing an anti-caking potassium nitrate according to claim 2, wherein the modification liquid in step S1 is specifically prepared by weighing sodium dodecyl sulfate, adding the sodium dodecyl sulfate into pure water at a temperature of 40 ℃ to 50 ℃ and stirring until the sodium dodecyl sulfate is completely dissolved, thereby preparing a transparent solution.
  5. 5. The method for producing anti-caking potassium nitrate according to claim 3, wherein the specific operation of removing calcium and magnesium ions and ammonium ions is that potassium carbonate is added to adjust the pH value of the solution to 8.5 to 9.0, potassium hydroxide is added to adjust the pH value of the solution to be more than 12, and the micro-boiling state is maintained until no ammonia smell escapes.
  6. 6. The method for producing the anti-caking potassium nitrate according to claim 3, wherein the specific operations of neutralizing, concentrating, crystallizing and centrifugally separating the filtered clear liquid are as follows: adjusting the pH value of the filtered clear liquid to 7.0 to 7.2 by using analytically pure nitric acid; concentrating the pH-value-adjusted solution under reduced pressure until the density is 1.30g/cm < 3 > to 1.32g/cm < 3 >; Cooling, crystallizing and centrifugally separating to obtain the high-purity potassium nitrate crystal.
  7. 7. The method for producing the anti-caking potassium nitrate according to claim 2, wherein the specific operation of primary mixing cladding in the step S2 adopts a layered spray method, the high-purity potassium nitrate crystals are layered, a certain amount of the anti-caking modifying liquid is sprayed in each layered crystal, and mechanical stirring and mixing are carried out for more than 2 hours at normal temperature after spraying is completed.
  8. 8. The method for producing an anti-caking potassium nitrate according to claim 7, wherein in the layer-by-layer spray method, each layer of high-purity potassium nitrate crystals laid is 50kg to 100kg in weight, and the anti-caking modifying liquid is used in such an amount that 10g to 100g of sodium dodecyl sulfate is consumed per 1000kg of high-purity potassium nitrate crystals.
  9. 9. The method for producing the anti-caking potassium nitrate according to claim 2, wherein the specific condition of the drying film forming in the step S3 is that the wet mixed material is spread in a baking pan, is placed in a baking oven at 90 ℃ for drying for more than 24 hours, and keeps a baking oven door in a non-closed state with a moisture discharging channel in the drying process.
  10. 10. The method for producing the anti-caking potassium nitrate according to claim 2, wherein the final mixing and sizing in the step S4 is specifically carried out by mechanically rotating and mixing the dried materials for more than 2 hours at normal temperature after passing through a vibrating screen.

Description

Method for producing anti-caking potassium nitrate Technical Field The application relates to the field of material science and engineering, in particular to a method for producing anti-caking potassium nitrate. Background Potassium nitrate is an important inorganic chemical raw material and is widely applied to the fields of agricultural fertilizers, food corrosion prevention, industrial glass manufacturing, ceramic glaze, daily chemical products and the like. Potassium nitrate is usually present in the form of a crystalline powder and has a certain hygroscopicity. In the storage, stacking and transportation processes after production, the water adsorbed on the surface of the crystal is easy to dissolve part of potassium nitrate to form saturated solution under the influence of environmental temperature and humidity change and self gravity, when the environment is dry or the temperature is reduced, the dissolved potassium nitrate is separated out again and forms a liquid bridge between crystal particles, so that the crystal is seriously adhered and agglomerated, and finally, a hard plate agglomeration is formed, so that the fluidity of the product is seriously lost, and the physical form of the product is changed. In order to solve the caking problem of potassium nitrate, the prior art generally adopts a method of adding an anti-caking agent, and inert inorganic powder such as talcum powder, kaolin, diatomite or silicon dioxide is added. The technical principle is that the fine powder is attached to the surface of potassium nitrate crystal by physical mixing, which plays a role in physical isolation, reduces the direct contact area between crystals and thus blocks the formation of crystal bridges. In the prior art, water insoluble substances are introduced, so that the clarity of the product is not up to the standard, inorganic anti-caking agents such as talcum powder, kaolin and the like widely used in the prior art are insoluble in water, and the physical isolation method can directly lead to turbidity of a solution after dissolving potassium nitrate, so that the content of the water insoluble substances is obviously out of standard, and the technical index requirements of the high-end application field cannot be met. Disclosure of Invention In order to solve the problem that the clarity of products does not reach the standard due to the introduction of water insoluble matters in the prior art, the application provides the silicon carbide reinforced perfluoro ether rubber high-temperature-resistant heat-conducting sealing composite material and the preparation process thereof. In a first aspect, the invention provides a process for the production of an anti-caking potassium nitrate. The method adopts high-purity potassium nitrate crystals as a base material and sodium dodecyl sulfate as an anti-caking agent, and the formula proportion of the anti-caking potassium nitrate is 10g to 100g of sodium dodecyl sulfate per 1000kg of high-purity potassium nitrate crystals. The production method comprises the following steps: S1, dissolving the sodium dodecyl sulfate with the formula amount into pure water to prepare anti-caking modified liquid; S2, uniformly spraying the anti-caking modified liquid on the surface of the high-purity potassium nitrate crystal, and primarily mixing to obtain a wet mixed material; S3, placing the wet mixed material in a heating environment for dehumidification and drying, evaporating water and forming a hydrophobic film on the surface of the crystal to obtain a dried material; and S4, secondary mixing is carried out on the dry materials, and then the anti-caking potassium nitrate is obtained. The preparation method of the high-purity potassium nitrate crystal comprises the steps of dissolving industrial potassium nitrate in water, adding ammonium nitrate to react at 80-90 ℃ to remove nitrite by using an oxidation-reduction principle, then adding ammonium sulfide to react at 80-90 ℃ to precipitate and remove heavy metal ions, sequentially adding potassium carbonate and potassium hydroxide to maintain a micro-boiling state, removing calcium magnesium ions and ammonium roots by using a precipitation and volatilization principle, finally adding zinc oxide and active carbon to remove excessive sulfur ions and organic impurities, and neutralizing, concentrating, crystallizing and centrifugally separating filtered clear liquid to obtain the high-purity potassium nitrate crystal. Further, the specific operation of preparing the modified liquid in the step S1 is that the sodium dodecyl sulfate is weighed and added into pure water with the temperature of 40-50 ℃ to be stirred until the sodium dodecyl sulfate is completely dissolved, so as to prepare transparent solution. Sodium lauryl sulfate has low solubility in cold water and is prone to form micelles, while at too high a temperature a significant amount of foam is easily produced or hydrolysis occurs. The dissolution temperature is control