37results about "Alkali metal nitrate shape formation" patented technology

The invention discloses a method for producing molten salt-grade potassium nitrate, comprising the following steps: Step S1 neutralization process: potassium hydroxide solution and nitric acid solution are mixed to undergo neutralization reaction to generate potassium nitrate to obtain the first potassium nitrate raw material solution, hydrogen The ratio of the amount of substances of potassium oxide and nitric acid is 1:1.01~1.02; step S2 evaporation process: the first potassium nitrate raw material liquid is evaporated and concentrated until the mass percentage concentration of potassium nitrate is 65~70%, and the second potassium nitrate is obtained Raw material liquid; step S3 spraying and granulating process: spraying and granulating the second potassium nitrate raw material liquid to obtain molten salt grade potassium nitrate as a final product. The method of the invention can directly produce potassium nitrate of high-purity molten salt grade, and has very good industrial value. Moreover, the process of the process of the present invention is simple and efficient in operation, easy to realize automatic production, strong in safety, and suitable for continuous, stable and rapid production of high-purity potassium nitrate.

The present invention discloses an industrial sodium nitrite product and its production method. The physical and chemical properties of said product are as follows: it is made into the form of ball or egg granular body, grain size is 0.5-3 mm, and the water content of the described granule body is less than or equal to 0.5%. Its production method uses the existent industrial sodium nitrite product as raw material, the above-mentioned raw material is heated and moten into liquid phase, and said liquid phase is sprayed and granulated so as to obtain the invented product. Said product features low water content, no blocking and good fluidity.

The invention provides a membrane-assisted nucleation cooling crystallization method, and belongs to the technical field of crystallization engineering. Solution to be crystallized is added into a crystallizing kettle, a computer and a stirring and temperature control device is started, and a cooling liquid loop is started. After a system is stabilized, a peristaltic pump is started, and the solution to be crystallized is conveyed to a membrane component. When crystal nucleuses appear in the membrane component, mother solution with the crystal nucleuses is conveyed to the crystallizing kettle and subjected to crystal growth. By controlling cooling liquid and operation conditions, generation of the crystal nucleuses and crystal growth are systematically regulated, so that an ideal crystal product is obtained.

The invention provides an oxidizing method for nitrite ions in desulfurization and denitrification waste liquid. The oxidizing method comprises the following steps of firstly carrying out solid-liquidseparation and deep dedusting on the desulfurization and denitrification waste liquid, then adjusting the pH value of the solution to be in the suitable range for oxidation treatment, completely oxidizing nitrites in the waste liquid into nitrates through a manner of combining an oxidizing agent and ultraviolet light to produce free radical, and finally obtaining a nitrate product. The oxidizingmethod provided by the invention has the beneficial effects that the operation is simple and convenient, the cost is low, the oxidizing efficiency is high, the problem of secondary pollution easily caused by the nitrite waste liquid is solved, and the recycling of all nitrogen elements in the waste liquid is realized, so that the application prospect is good.

The invention relates to a preparation method of salt nano-particles. The preparation method comprises the following steps of putting inorganic salt of a solid in a vessel, and providing a basement with a smooth surface; regulating a temperature of a heating device to be higher than a melting point of the inorganic salt and lower than a decomposition temperature of the inorganic salt, and heatingthe vessel and the basement with the heating dvice to enable the solid inorganic salt to be molten into a molten liquid state; and dipping the molten inorganic salt with a rod body which is not reacted with the molten inorganic salt, dripping the molten inorganic salt on the basement, into which the molten inorganic salt does not infiltrate, then removing droplets of the molten inorganic salt fromthe basement, and performing cooling to obtain inorganic salt nano-particles on the surface of the basement. In the preparation method provided by the invention, by using a melting-cooling method toprepare the salt nano-particles, the salt nano-particles with the particle size being between several nanometers and several micrometers can be obtained; and particularly, through the preparation method provided by the invention, the salt nano-particles with the size being 6nm or below can be obtained, so that the preparation method exploits a new measure of preparation of small-particle size saltnano-particles.

Provided is a method for pelleting spherical fine particle of sodium nitrate, which comprises the following steps: 1) melting industrial sodium nitrate in a salt melting furnace, introducing into a high-level insulation buffer tank, placing in an atomizer located on top of the pelleting tower, atomizing to obtain fog droplets with size of 30 μm-0.5 mm; 2) introducing freeze-dried high-pressure air into the pelleting tower in a tangent direction from the upper inlet pipe of the tower, so that the sodium nitrate fog droplets obtained in step 1) fall spirally along the wall in the pelleting tower, to obtain sodium nitrate particle; 3) collecting the cooled sodium nitrate particle at the bottom of the tower, and packaging. Sodium nitrate particle with lower water content, higher roundness, and smaller size can be obtained, and continuous production can be realized by the method.

The invention provides a recrystallization method for preparing small-particle nitrate, aiming at the problems that nitrate has a poor appearance, and has sharp edges and corners, relatively great granularity and the like. The recrystallization method comprises the following steps: 1) completely dissolving the nitrate into a solvent; filtering to obtain filtrate for later use, wherein the nitrateis one of sodium nitrate, potassium nitrate, cesium nitrate, barium nitrate, calcium nitrate and lithium nitrate, and the solvent is water; 2) injecting a counter solvent into a crystallization kettleand starting to stir, wherein the counter solvent is absolute ethyl alcohol or methanol or acetone and the volume of the counter solvent is 2 to 5 times as much as that of the solvent; 3) after dropwise adding the filtrate into the crystallization kettle, continually stirring to carry out crystallization; and 4) filtering, washing and drying a mixture in the crystallization kettle.

The present disclosure concerns fertilizer particles comprising calcium nitrate and potassium nitrate. It is found that fertilizer particles comprising 43 to 47% w/w calcium nitrate and 46 to 54% w/w potassium nitrate can be produced by melt granulation. Due to undercooling problems, such particles were not expected to be suitable for industrial production by melt granulation. However, the present disclosure provides a composition which forms a low viscosity melt with short solidification time. This was successfully achieved by reducing the water content of a fertilizer melt comprising 43 to 47% w/w calcium nitrate and 46 to 54% w/w potassium nitrate to less than 3% w/w of the melt.

The present invention discloses an industrial sodium nitrate product and its production method. The physical and chemical properties of said product are: it is spherical or egg-shaped granule, grain size is 0.5-3 mm, and its water content is less than or equal to 0.5%. Its production method is as follows: using industrial sodium nitrate in the existent technology as raw material, heating and melting the above-mentioned raw material to obtain liquid phase material, and spray-granulating said liquid phase so as to obtain the invented product. Said invented product features low water content, nocaking and good fluidity.

The invention discloses a nitrate system molten salt heat conduction material and a preparation method thereof. The method comprises the following steps: S1, neutralizing: neutralizing a sodium sulfate solution and a nitric acid solution to form a first sodium nitrate raw material solution having a pH value of 3.5-4.5 and a mass percentage concentration of 23-28%; S2, removing carbon oxides: removing the carbon oxides in the first sodium nitrate raw material solution to form a second sodium nitrate raw material solution; S3, evaporating: carrying out evaporative concentration on the second sodium nitrate raw material solution to obtain a third sodium nitrate raw material solution having a mass percentage concentration of 63-67%; S4, crystallizing and dehydrating: crystallizing and dehydrating the third sodium nitrate raw material solution to obtain a solid sodium nitrate raw material; and S5, drying: drying the solid sodium nitrate raw material to obtain the final product molten salt grade sodium nitrate. The method allows the high-purity molten salt grade sodium nitrate to be directly produced, and has the advantages of simplicity, easiness in control, realization of automatic production, and suitableness for safe, continuous, stable and rapid production of high-purity sodium nitrate.

The invention discloses an extraction agent for preparing potassium nitrate with a nitric acid-potassium chloride extraction method. The extraction agent is prepared from isoamyl alcohol, n-butyl alcohol, tri-n-octylaminetri-octyl tertiary amine, n-caprylic alcohol according to a volume ratio of 1 to (0.1 to 0.5) to (3 to 10) to (1.3 to 3). The extractant provided by the invention has a good extraction effect and high selectivity for hydrochloric acid in a nitric acid-potassium chloride reaction system, the hydrochloric acid can be extracted without while not extracting nitric acid, the nitricacid serving as a raw material is saved, the purity of the nitric acid serving as a by-product is improved; the nitric acid prepared by back extraction can be directly taken as a product for selling.

The invention discloses a preparation method of sodium nitrate. The method comprises the following steps: (1) double decomposition: mixing calcium nitrate with a gypsum filter residue washing liquid in the subsequent procedure and a returned sodium nitrate mother liquor, stirring and adding sodium sulfate to carry out double decomposition, filtering out generated dihydrate gypsum, washing with clear water, and returning washing liquor; and leaving the generated sodium nitrate in the filtrate; (2) purification for removal of calcium: neutralizing by adding stone flour and soda ash into the filtrate in the last step, heating to boiling, filtering, filtering out calcium carbonate, and drying to prepare fertilizer-grade dicalcium phosphate; and (3) evaporative crystallization separation: concentrating by sending the neutralized filtrate in the last step into a double-effect evaporator, and cooling for crystallization to obtain sodium nitrate crystal slurry: adding the sodium nitrate crystal slurry into a centrifugal separator, and separating to obtain a sodium nitrate product. The method can be adopted to convert waste residue calcium nitrate discharged from nitrophosphate fertilizer equipment by a freezing method into the sodium nitrate product, and has good economic benefit and environmental protection effect.

The invention belongs to the technical field of chemical engineering, and particularly relates to a sodium nitrate preparation device and method.The sodium nitrate preparation device comprises a crystallizer, a device body, a guide cylinder and a stirring shaft, a first scraping plate and a second scraping plate are installed on the stirring shaft and the guide cylinder, and crystal scars generated on the inner surface of the crystallizer and the surface of the stirring shaft are removed; re-dissolving and crystallizing in the mother liquor; a spring is mounted on the second scraping plate, the second scraping plate is driven to vibrate under the action of a convex block on the stirring shaft, and crystal scars attached to the second scraping plate are removed; the device is simple in structure, effectively removes crystal scars on the stirring shaft and the inner wall of the crystallizer, and re-dissolves and crystallizes the crystal scars in mother liquor, so that yield reduction caused by the crystal scars on the inner wall of the crystallizer is avoided, meanwhile, the cleaning time of the inner wall of the crystallizer is shortened, and the working time and yield of the crystallizer are increased.

The invention discloses a high-purity potassium nitrate tablet which is formed by extruding potassium nitrate crystal particles with the mesh number of 25-150 and the purity of 99.7% or above. The thickness of the high-purity potassium nitrate tablet is 3-15 mm, and the diameter of the high-purity potassium nitrate tablet is 5-15 mm. A layer of anti-blocking agent film is arranged on the surface of the high-purity potassium nitrate tablet, or a layer of anti-blocking agent film is arranged on the surface of the potassium nitrate crystal particles forming the high-purity potassium nitrate tablet. The invention relates to a preparation method of the high-purity potassium nitrate tablet, which comprises the following steps: screening high-purity potassium nitrate crystals with the purity of more than 99.7%, selecting crystal particles with the particle size of 25-150 meshes, and tabletting, or uniformly spraying an anti-blocking agent on the high-purity potassium nitrate crystals before tabletting, or coating the surface of the high-purity potassium nitrate tablet with the anti-blocking agent after tabletting. The high-purity potassium nitrate tablet has the advantages that the high-purity potassium nitrate tablet is difficult to cake and more convenient to store, transport and use.

The invention belongs to the technical field of radioactive waste utilization, and particularly relates to a method for producing nitric acid and sodium nitrate by using nuclear-grade hafnium oxide production discharged wastewater. The raffinate generated after extraction and enrichment of hafnium in the production process of nuclear-grade hafnium dioxide is used as feed liquid for producing nitric acid and sodium nitrate. Feeding the material liquid into a double-effect evaporation crystallizer for reduced pressure distillation, feeding the material liquid into a first-effect evaporator for distillation and concentration, feeding the concentrated liquid into a second-effect evaporator for distillation and crystallization, collecting second-effect distillate to obtain a nitric acid product, and filtering crystal mush by a centrifugal machine to obtain a sodium nitrate product. The method is simple in technological process, full in resource utilization and low in cost, the recovery rate of nitric acid in the raffinate can reach 80% or above, the recovery rate of sodium nitrate can reach 95% or above, the reduction amount of waste liquid is 90% or above, environment friendliness is achieved, and obvious social benefits and economic benefits are achieved.

The invention relates to a method for drying salts with a water of crystallisation content in convective apparatuses that can additionally be indirectly heated. The invention is primarily characterised in that the drying process takes place with a moisture content of the drying gas above a determined level. The gas surrounding the salt particles during the drying process therefore has a specific humidity. In this way, the rate of drying is positively influenced.