CN111533099A - Production method of water-soluble monoammonium phosphate - Google Patents
Production method of water-soluble monoammonium phosphate Download PDFInfo
- Publication number
- CN111533099A CN111533099A CN202010455228.5A CN202010455228A CN111533099A CN 111533099 A CN111533099 A CN 111533099A CN 202010455228 A CN202010455228 A CN 202010455228A CN 111533099 A CN111533099 A CN 111533099A
- Authority
- CN
- China
- Prior art keywords
- water
- solid
- monoammonium phosphate
- liquid phase
- liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/28—Ammonium phosphates
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B7/00—Fertilisers based essentially on alkali or ammonium orthophosphates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Fertilizers (AREA)
Abstract
The invention relates to a production method of water-soluble monoammonium phosphate, belonging to the technical field of cleaning, processing and utilizing phosphorite. A production method of water-soluble monoammonium phosphate comprises the following steps: a. mixing nitric acid and phosphorite, reacting for 0.5-2 h at 30-70 ℃, and performing solid-liquid separation to obtain acidolysis solution; b. neutralizing the acidolysis solution until the pH value is 6.5-8, and performing solid-liquid separation to obtain a solid phase I and a liquid phase I; c. mixing the solid phase I with a sulfuric acid solution, reacting for 0.3-2 h at 30-70 ℃, and carrying out solid-liquid separation to obtain a solid phase II and a liquid phase II; neutralizing the liquid phase II until the pH value is 4.0-4.5, and then carrying out solid-liquid separation to obtain a solid phase III and a liquid phase III; wherein the liquid phase III is processed to obtain the water-soluble monoammonium phosphate. The method of the invention completely separates phosphorus and calcium in the phosphorite, greatly improves the utilization rate of elements such as calcium, phosphorus and the like, and can directly produce the water-soluble monoammonium phosphate.
Description
Technical Field
The invention relates to a production method of water-soluble monoammonium phosphate, belonging to the technical field of cleaning, processing and utilizing phosphorite.
Background
The phosphorite resource is an important strategic resource of China, is a material basis of phosphorus chemical industry, has non-regenerability, is rich in phosphorite resource in China, but is a medium-low grade phosphorite which is difficult to directly utilize by more than 80 percent.
The phosphorite processing mainly comprises a thermal method and a wet method, wherein the wet method accounts for the majority. The wet process mainly comprises a hydrochloric acid method, a sulfuric acid method and a nitric acid method. Most enterprises in China produce phosphoric acid and downstream phosphate products by a sulfuric acid process, however, 1 ton of phosphoric acid (P) is produced2O5Calculated) 5-5.5 tons of waste phosphogypsum are discharged, 8800 ten thousand tons are discharged annually, the accumulated stockpiling reaches hundreds of millions of tons, and the comprehensive utilization rate is lower than 30%. The phosphogypsum is mainly discharged in open air by stacking, occupies a large amount of land and pollutes the ecological environment. Therefore, the development of a phosphorus resource cleaning processing technology is urgently needed, the solid waste emission in the production and utilization process is reduced, and the green, clean and sustainable development of the phosphorus chemical industry is realized. The phosphoric acid prepared by the hydrochloric acid wet method is hardly influenced by raw materials, the application range is wide, and the phosphogypsum solid waste is not generated. However, the hydrochloric acid method for processing phosphorite has strong medium corrosivity, high requirement on equipment material and large equipment investment; the calcium chloride byproduct in the process is difficult to utilize, the production and application limitations are very obvious, and the problem of processing of phosphorite is not solvedThe solid waste discharge problem in the process. Compared with sulfuric acid method and hydrochloric acid method, the method has more significance and prospect in treating phosphorite by nitric acid. The nitric acid plays a dual role in the process of treating the phosphorite, the phosphorite is decomposed by utilizing the chemical energy of the nitric acid, and the nitric acid can be converted into a nitrogen fertilizer for utilization, so that the utilization rate of raw materials is improved. And the nitric acid method does not generate solid waste, and is a clean processing technology.
The ammonium calcium nitrate is an excellent agricultural chemical fertilizer containing nitrogen and calcium elements. The production process of calcium ammonium nitrate mainly includes neutralization method and nitrophosphate fertilizer by-product method. Wherein, the technological process of the nitrophosphate fertilizer by-product method comprises the following steps: the acidolysis solution of nitric acid decomposing phosphorite is frozen and crystallized to separate out Ca (NO)3)2·4H2And O. Dissolving the precipitated calcium nitrate in water, neutralizing with liquid ammonia or ammonia water, filtering, concentrating and granulating the filter cake to obtain calcium ammonium nitrate product, and using the filtrate to produce nitrophosphate fertilizer. However, the method is not suitable for medium and low grade phosphorite, even high quality phosphorite, the precipitation rate of calcium nitrate in acidolysis solution after acidolysis is about 80% at most, so that the calcium nitrate content in subsequent solution and the water insoluble content in compound fertilizer exceed the standard, and high quality fertilizer is difficult to produce.
The monoammonium phosphate is used as a high-concentration nitrogen-phosphorus compound fertilizer, has obvious agricultural yield-increasing effect and is the most important compound fertilizer variety internationally recognized. The traditional ammonium phosphate production processes of a phosphoric acid concentration method and a slurry method tend to be mature, but impurities in wet-process phosphoric acid are not purified in the production process, so that the produced ammonium phosphate has low purity and can only reach the fertilizer grade. There are two main production methods for industrial phosphoric acid: one is prepared by taking thermal phosphoric acid as a raw material to perform neutralization reaction with ammonia and then crystallizing; the other is prepared by taking wet-process phosphoric acid as a raw material, removing impurities, reacting with ammonia, and crystallizing. The thermal phosphoric acid process has high energy consumption, and the wet phosphoric acid has high requirement on the purification technology and complex process. Before the traditional sulfuric acid method wet-process phosphoric acid is used for preparing industrial ammonium phosphate, a large amount of impurities contained in a solution are removed by methods such as organic solvent extraction, ion exchange, chemical precipitation and the like, and the methods comprise the following steps: SO (SO)4 2-、F-、Fe3+、Al3+、Mg2+Etc., not only the process is complicated, but also phosphorusThe yield is not high. In addition, the water-soluble monoammonium phosphate industry has been rapidly developed in recent years, the product purity is slightly poorer than that of industrial monoammonium phosphate, but is better than that of fertilizer-grade monoammonium phosphate, and the standard of water-soluble monoammonium phosphate is issued in 2016 (HG/T5048-2016).
CN 101838158A discloses a method for producing green high-quality high-efficiency compound fertilizer ammonium phosphate by using industrial phosphoric acid quality phosphoric acid, which is a method for preparing ammonium phosphate by directly reacting with liquid ammonia, wherein the impurity content of blast furnace phosphoric acid produced by supplying heat by burning coke and coal is low. Although the method uses coke and coal to replace electricity to provide heat, the process energy consumption is still high. Most enterprises in China adopt a wet-process phosphoric acid process, and the method is not suitable for basic production layout conditions of the enterprises in China. CN 102134063A discloses a method for producing industrial phosphoric acid, industrial ammonium phosphate, video and phosphoric acid from middle and low grade phosphorite by one-step extraction with hydrochloric acid. The main technological process includes the steps of pulping the acidolysis solution obtained by decomposing phosphate rock with hydrochloric acid, dissolving with hydrochloric acid, extracting with tributyl phosphate, concentrating and decolorizing to obtain industrial phosphoric acid, adding ammonia to obtain industrial ammonium phosphate, and dearsenizing and heavy metal treatment to obtain food grade phosphoric acid. Although the method can obtain purer industrial phosphoric acid, the method has long process flow, the use amount and washing of the extracting agent increase the production cost, and the phosphorus loss is gradually increased in the purification process to reduce the phosphorus yield. CN 103130205A discloses a method for producing industrial-grade monoammonium phosphate and co-producing water-soluble ammonium sulfate phosphate. The main process flow is that agricultural ammonium phosphate is used as raw material, after water is added for dissolving, ammonium bicarbonate or ammonia is added for adjusting the pH value of the solution, the filtrate after filtration and separation is concentrated, crystallized, filtered and dried to obtain a monoammonium phosphate product, and the filtrate is concentrated and dried to obtain ammonium sulfate phosphate. The agricultural ammonium phosphate raw material in the method is prepared by adopting wet-process phosphoric acid of a sulfuric acid method, the requirement on the grade of phosphorite is high, and part of phosphorus in the raw material enters ammonium phosphate sulfate, so that the yield of phosphorus in industrial ammonium phosphate is low. CN 104045071A discloses a high-efficiency impurity-removing production method for extracting industrial monoammonium phosphate from ammonium phosphate production. The main process flow is that phosphoric acid and ammonia are neutralized for three times, clear liquid obtained by filtration after the second neutralization is taken to be neutralized again to obtain industrial monoammonium phosphate, and the rest is used for producing fertilizer ammonium phosphate. Although the process can reduce the impurity content to prepare the industrial monoammonium phosphate by multiple times of neutralization, the phosphorus in the industrial monoammonium phosphate accounts for a very low proportion of the phosphorus in the raw materials, and most of the phosphorus in the industrial monoammonium phosphate is converted into fertilizer ammonium phosphate with high impurity content. CN 105197905A discloses a production method for extracting feed-grade monocalcium phosphate and industrial-grade ammonium phosphate produced by the co-production of phosphorite. The main technological process is that phosphoric acid is used to hydrolyze floated phosphate concentrate, acidolysis solution is filtered to remove extraction residue, filtrate is concentrated, cooled and crystallized to obtain calcium dihydrogen phosphate, and filtrate is used to prepare ammonium dihydrogen phosphate. The yield of phosphorus in the ammonium phosphate is low in the method, and most of phosphorus is converted into monocalcium phosphate.
Patent CN109593003A discloses a production method for increasing the water-soluble phosphorus content of citrate soluble phosphorus fertilizer, which is to convert citrate soluble phosphorus in citrate soluble phosphorus fertilizer into water-soluble phosphorus by using urea sulfate through the steps of mixing, curing and the like, thereby increasing the water-soluble phosphorus content. The process has the advantages of long flow, complex operation, long required time and higher production cost. Patent CN106219505A discloses a method for converting citrate soluble phosphorus into water soluble phosphorus, which is to dissolve citrate soluble phosphorus with strong acid and then add activator, stabilizer, etc. to obtain stable water soluble phosphorus slurry. The process needs strong acid such as sulfuric acid and nitric acid, and the obtained water-soluble phosphorus slurry is strong acid and is not beneficial to agricultural application. Patent CN201310396218.9 discloses a method for producing fully water-soluble monoammonium phosphate by using wet-process phosphoric acid, i.e. solid-liquid separation is performed on slurry after wet-process phosphoric acid ammonification reaction, and filtrate is concentrated and dried to obtain fully water-soluble monoammonium phosphate. The method has long process flow, white fertilizer can be generated in the production process, and the yield of phosphorus is low. Patent CN201410245006.5 discloses a method for producing fully water-soluble monoammonium phosphate and co-producing magnesium ammonium phosphate by using wet-process phosphoric acid, namely, the fully water-soluble monoammonium phosphate and magnesium ammonium phosphate products are prepared by the wet-process phosphoric acid through three times of ammoniation reaction, aging, solid-liquid separation, concentration, crystallization and other steps. The monoammonium phosphate product prepared by the method has high water-soluble phosphorus content, but the process is complex, white fertilizer and ammonium magnesium phosphate are byproducts, and the phosphorus yield is low.
The phosphorus compound fertilizer industry in China mainly takes sulfuric acid process wet process phosphoric acid as a main material, but sulfur in China has high external dependence, sulfur resources are constraint resources of phosphorus compound fertilizer production in China, the comprehensive utilization rate of phosphogypsum which is a byproduct of the sulfuric acid process wet process phosphoric acid is not high, the comprehensive utilization additional value is not high, a large amount of phosphogypsum is still stockpiled, and environmental pollution is caused, and the phosphogypsum becomes one of the restriction factors influencing the development of the phosphorus compound fertilizer industry in China. In addition to the problem of solid waste of phosphogypsum, the environmental protection pressure caused by the pollution of three wastes in the industry is a main problem in the ammonium phosphate industry. Therefore, upgrading and modification of process technology, improvement of technical equipment level, energy conservation and consumption reduction, improvement of phosphorus yield and the like are inevitable trends in industrial development. Therefore, the production method for preparing the water-soluble monoammonium phosphate by decomposing the low-grade phosphate ore with the nitric acid can effectively utilize the increasingly depleted phosphate ore resources in China, reduce the use amount of sulfuric acid and relieve the external dependence of sulfur.
Disclosure of Invention
Aiming at the problems, the technical problem to be solved by the invention is to provide a preparation method of water-soluble monoammonium phosphate, and the method for preparing the water-soluble monoammonium phosphate has the advantages of simple process, high phosphorus yield and low sulfuric acid consumption.
A production method of water-soluble monoammonium phosphate comprises the following steps:
a. mixing nitric acid and phosphorite, reacting for 0.5-2 h at 30-70 ℃, and performing solid-liquid separation to obtain acidolysis solution;
b. neutralizing the acidolysis solution until the pH value is 6.5-8, and performing solid-liquid separation to obtain a solid phase I and a liquid phase I;
c. mixing the solid phase I with a sulfuric acid solution, reacting for 0.3-2 h at 30-70 ℃, and carrying out solid-liquid separation to obtain a solid phase II and a liquid phase II; neutralizing the liquid phase II until the pH value is 4.0-4.5, and then carrying out solid-liquid separation to obtain a solid phase III and a liquid phase III; wherein the liquid phase III is water-soluble monoammonium phosphate.
In one embodiment, in step c, the liquid phase II is neutralized to a pH of 4.1 to 4.5.
In one embodiment, in step a, the phosphate ore is in powder or slurry form, and the concentration of the nitric acid is 30-70 wt% based on the water content in the phosphate ore being 0-40 wt%.
In one embodiment, in the step a, the amount of the nitric acid is 0.9-1.2 times of the theoretical acid consumption of complete reaction of the phosphorite; preferably, the dosage of the nitric acid is 0.9-1.1 times of the theoretical acid consumption of the complete reaction of the phosphorite.
In one embodiment, in step a, the solid-liquid separation is performed in two steps, wherein the liquid is subjected to sedimentation separation, and then the liquid after sedimentation separation is subjected to filtration separation.
In one embodiment, in step b, the neutralization is with a basic neutralizing agent; preferably, the alkaline neutralizing agent is at least one of gas ammonia, ammonia water, limestone, lime milk, ammonium carbonate and ammonium bicarbonate; further preferably, the alkaline neutralizing agent is calcium carbonate, ammonia and milk of lime.
In one embodiment, in step c, the concentration of the sulfuric acid solution is 30 to 60 wt%; the dosage of the sulfuric acid solution is 0.9-1.2 times of the theoretical acid consumption of the complete reaction of the solid phase I; preferably, the dosage of the sulfuric acid solution is 0.95 to 1.05 times of the theoretical acid consumption of the complete reaction of the solid phase I.
In one embodiment, the neutralizing agent used to neutralize the liquid phase ii in step c is ammonia gas or liquid ammonia.
In one embodiment, in step c, the liquid phase iii is processed to produce solid water-soluble monoammonium phosphate.
The preparation method of the solid water-soluble monoammonium phosphate comprises the following steps: and evaporating, concentrating and drying the liquid phase III to obtain solid water-soluble monoammonium phosphate.
In one embodiment, the liquid phase I is added with a substance containing nutrient elements to adjust the product nutrient, so as to obtain calcium nitrate fertilizer or calcium ammonium nitrate fertilizer; preferably, the nutrient element-containing substance is at least one of ammonia, ammonium nitrate and calcium nitrate.
The invention has the beneficial effects that:
1. the invention can directly utilize middle-low grade phosphorite without carrying out phosphorite flotation;
2. the method of the invention completely separates phosphorus and calcium in the phosphorite, greatly improves the utilization rate of elements such as calcium, phosphorus and the like, and has better economic benefit;
3. the invention can directly produce water-soluble monoammonium phosphate; obtaining high-purity calcium sulfate dihydrate;
4. the amount of the by-product slag in the process of producing the water-soluble monoammonium phosphate is greatly reduced;
5. the process has low comprehensive cost, basically generates no solid waste, realizes the clean processing and utilization of the phosphorite, and has good economic benefit, social benefit and wide industrial application prospect;
6. compared with the traditional sulfuric acid method and the nitric acid-sulfuric acid method, the method has the advantages that the amount of the used sulfuric acid is greatly reduced;
7. the invention does not relate to a freezing step and has low process energy consumption.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
A production method of water-soluble monoammonium phosphate comprises the following steps:
a. mixing nitric acid and phosphorite, reacting for 0.5-2 h at 30-70 ℃, and then carrying out solid-liquid separation to obtain a liquid phase, namely acidolysis solution, and a solid phase, namely acid-insoluble substances;
b. neutralizing the acidolysis solution until the pH value is 6.5-8, and performing solid-liquid separation to obtain a solid phase I and a liquid phase I;
c. mixing the solid phase I with a sulfuric acid solution, reacting for 0.3-2 h at 30-70 ℃, and carrying out solid-liquid separation to obtain a solid phase II and a liquid phase II; neutralizing the liquid phase II until the pH value is 4.0-4.5, and then carrying out solid-liquid separation to obtain a solid phase III and a liquid phase III; wherein the liquid phase III is water-soluble monoammonium phosphate.
Wherein, in the step a, the main reactions are as follows:
Ca5F(PO4)3+10HNO3＝5Ca(NO3)2+3H3PO4+HF↑。
in step a, decomposing phosphorite with nitric acid to obtain P in acidolysis solution2O5The concentration is low, the decomposition rate of the iron-aluminum-containing low-activity ore in the phosphorite is low, the elution amount of insoluble impurities is small, and a part of the insoluble impurities exists in an acid insoluble substance and is separated out by filtration. Compared with a sulfuric acid method, the method has the advantages that impurity ions such as Fe and Al in the solution are less, and the MER value of the solution is small.
Wherein, the
When the solution with low MER value is used for subsequent acidolysis solution treatment, the complex precipitation of phosphorus and impurity ions can be further prevented, so that the yield of phosphorus is improved.
In the step b, the pH value is neutralized to be more than or equal to 6.5 and less than or equal to 8.0, and the aim is to completely precipitate the phosphorus in the acidolysis solution. After solid-liquid separation, the solid phase I is mainly CaHPO4、Ca3(PO4)2And CaF2And a small amount of Fe3+、Al3+、Mg2+The metal phosphate of (a); liquid phase I is predominantly NO3 -、Ca2+And a trace amount of H2PO4 -、HPO4 2-。
In step c, the reactions that occur are mainly:
CaHPO4+H2SO4+2H2O＝CaSO4·2H2O↓+H3PO4
in step c, the solid phase I is subjected to secondary acidolysis with a sulfuric acid solution, Ca2+The calcium sulfate dihydrate obtained by the method has high purity, and α -hemihydrate gypsum with good performance can be obtained through conversion.
Neutralizing the liquid phase II to pH 4.0-4.5 for the purpose of precipitating a small amount of Fe dissolved out of the solution3+、Al3+Impurities, so that the content of impurity ions in the solution is less, and the aim of purifying the phosphoric acid solution is fulfilled. Wherein, the solid phase III is the white fertilizer, and the components of the white fertilizer are metal phosphate, mainly ferric phosphate and aluminum phosphate.
The traditional method for separating calcium and phosphorus in a wet-process phosphoric acid system by a nitric acid method comprises the following steps: firstly, carrying out acidolysis on medium-low grade phosphorite, directly freezing and crystallizing the obtained acidolysis solution, and separating out CaNO3.4H2And O. Compared with the traditional method, the method of the invention greatly increases the separation rate of calcium and phosphorus. The reason is that: the phosphorus is completely precipitated from the solution by adopting a neutralization method and is separated from excessive calcium ions. And carrying out acidolysis on the calcium phosphate precipitate by using sulfuric acid, combining calcium ions with sulfate radicals to generate calcium sulfate precipitate, and completely releasing the phosphate radicals from the calcium phosphate. Thus, phosphorus and calcium are completely separated in a two-step operation and the filtrate is used to produce water-soluble monoammonium phosphate or other phosphorus-containing fertilizers.
In a specific embodiment, in order to increase the precipitation rate of impurity ions, in step c, the liquid phase II is neutralized to pH 4.1-4.5.
In a specific embodiment, in step a, the phosphorite is in powder or slurry form, and is in powder form when the water content of the phosphorite is 0%, and the phosphorite becomes slurry with the increase of the water content, for example, is in pulp when the water content of the phosphorite is 40%. In the method of the present invention, the concentration of the nitric acid solution needs to be strictly controlled. The concentration of the nitric acid solution is 30-70 wt% calculated by the water content in the phosphorite being 0-40 wt%, that is, when the water content in the raw material phosphorite is 0-40 wt%, the concentration of the nitric acid solution is controlled to be 30-70 wt%, and if the water content in the raw material phosphorite exceeds 40 wt%, the concentration of the nitric acid solution needs to be calculated according to the water content in the phosphorite.
In one embodiment, in the step a, the amount of the nitric acid is 0.9-1.2 times of the theoretical acid consumption of complete reaction of the phosphorite; preferably, the dosage of the nitric acid is 0.9-1.1 times of the theoretical acid consumption of the complete reaction of the phosphorite.
The theoretical acid consumption of the complete reaction of the phosphorite can be calculated according to the content of each component in the phosphorite. For example, the main components of a certain phosphorite reacting with acid are calcium oxide, magnesium oxide, iron oxide and aluminum oxide, and the theoretical acid consumption of the phosphorite in which the calcium oxide, the magnesium oxide, the iron oxide and the aluminum oxide completely react, that is, the theoretical acid consumption of the phosphorite in which the calcium oxide, the magnesium oxide, the iron oxide and the aluminum oxide completely react can be calculated according to the contents of the components.
Wherein, the solid-liquid separation in the step a can be carried out by adopting a conventional method.
In a specific embodiment, a plate and frame filter may be used for solid-liquid separation.
In another specific embodiment, in step a, the solid-liquid separation is performed in two steps, wherein the liquid is subjected to sedimentation separation, and then the liquid after sedimentation separation is subjected to filtration separation.
In one embodiment, in step b, the neutralization is with a basic neutralizing agent; preferably, the alkaline neutralizing agent is at least one of gas ammonia, ammonia water, limestone, lime milk, ammonium carbonate and ammonium bicarbonate; further preferably, the alkaline neutralizing agent is calcium carbonate, ammonia and milk of lime.
In one embodiment, in step c, the concentration of the sulfuric acid solution is 30 to 60 wt%; the dosage of the sulfuric acid solution is 0.9-1.2 times of the theoretical acid consumption of the complete reaction of the solid phase I; preferably, the dosage of the sulfuric acid solution is 0.95 to 1.05 times of the theoretical acid consumption of the complete reaction of the solid phase I.
Wherein, the theoretical acid consumption in step c can be determined according to Ca in solid phase I2+In the content of H2SO4With Ca2+Is 1:1, calculated as H2SO4The amount of (A) is the theoretical amount of acid consumed.
In one embodiment, the neutralizing agent used to neutralize the liquid phase ii in step c is ammonia gas or liquid ammonia.
For ease of storage, transport, and use, in one particular embodiment, in step c, liquid phase iii is processed into solid, water-soluble monoammonium phosphate.
The preparation method of the solid water-soluble monoammonium phosphate comprises the following steps: and evaporating, concentrating, drying and the like the liquid phase III to obtain solid water-soluble monoammonium phosphate.
The following reactions mainly occur for the production of water-soluble monoammonium phosphate:
H3PO4+NH3＝NH4H2PO4；
in one embodiment, the liquid phase I is added with a substance containing nutrient elements to adjust the product nutrient, so as to obtain calcium nitrate fertilizer or calcium ammonium nitrate fertilizer; preferably, the nutrient element-containing substance is at least one of ammonia, ammonium nitrate and calcium nitrate.
The following reactions mainly occur in the production of calcium ammonium nitrate:
H++NO3 -+NH3+Ca2+→5Ca(NO3)2·NH4NO3·10H2O。
phosphate rock commonly used in the art is suitable for use in the present invention. In a specific embodiment, P in the phosphate ore2O5The content is 15-30 wt%; preferably, the content of F in the phosphorite is 1.5-3.0 wt%.
The following examples are provided to further illustrate the embodiments of the present invention and are not intended to limit the scope of the present invention.
Specific components of phosphate ores used in the following examples are shown in table 1.
TABLE 1 Total analysis of phosphorite used in the examples
Example 1
Phosphorus ore P was selected in this example2O5、CaO、MgO、Fe2O3、Al2O3、SiO2And the contents of F are 27.96%, 41.30%, 1.48%, 1.94%, 1.03%, 9.93% and 2.99% respectively, and the ground phosphate rock is prepared. The specific process comprises the following steps:
(1) primary acidolysis: mixing phosphorus ore pulp with the water content of 30% and a nitric acid solution, reacting for 1.5h at 50 ℃ to obtain a solid-liquid mixture, and carrying out solid-liquid separation to obtain an acid insoluble substance and a liquid phase; wherein, the ground phosphate rock is 100g, and the 45 wt% nitric acid solution is 224 g; wherein the mass of the acidolysis solution is 343g, and the P of the acidolysis solution2O5The content is 7.9 percent, and the content of CaO is 11.7 percent;
(2) neutralizing: neutralizing the liquid phase obtained in the step (1) by ammonia until the pH value of the solution is 6.5; then carrying out solid-liquid separation to obtain a liquid phase I and 65g of a solid phase I;
(3) nutrient regulation: mixing the liquid phase I with a proper amount of additives, concentrating and drying to obtain a calcium (ammonium) nitrate fertilizer;
(4) secondary acidolysis: mixing the solid phase I with 82.5g of 45 wt% sulfuric acid solution, and reacting at 50 ℃ for 0.5h to obtain a mixed solution;
(5) solid-liquid separation: carrying out solid-liquid separation on the mixed solution obtained in the step (4) to obtain a solid phase II and a solution II, washing and filtering the solid phase II with hot water to obtain calcium sulfate dihydrate, wherein the washing water is used for preparing a sulfuric acid solution;
(6) neutralizing and removing impurities: neutralizing the liquid phase II with ammonia gas until the pH value of the solution is 4.5, and performing solid-liquid separation to obtain a liquid phase III and a solid phase III;
(7) concentrating and drying: the liquid phase III was evaporated, concentrated and dried to obtain 39.1g of water-soluble monoammonium phosphate. Wherein contains P2O560.8 percent, contains 11.8 percent of N, and meets the indexes HG/T4133-2010 industrial monoammonium phosphate 2016 of water-soluble monoammonium phosphate.
Example 2
Phosphorus ore P was selected in this example2O5、CaO、MgO、Fe2O3、Al2O3、SiO2And F contents of 18.12%, 29.46%, 2.74%, 1.63%, 3.73%, 34.53% and 1.62% respectively, and making into powdered rock phosphate. The specific process comprises the following steps:
(1) primary acidolysis: mixing the phosphorus ore pulp with the water content of 20% with a nitric acid solution, reacting for 1h at 60 ℃ to obtain a solid-liquid mixture, and carrying out solid-liquid separation to obtain an acid insoluble substance and a liquid phase; wherein, the ground phosphate rock is 100g, and the 65 wt% nitric acid solution is 150 g; wherein the mass of the acidolysis solution is 230g, and the mass of the acidolysis solution is P2O5The content is 7.8 percent, and the content of CaO is 12.7 percent;
(2) neutralizing: neutralizing the liquid phase obtained in the step (1) by using ammonium carbonate until the pH value of the solution is 8.0; then carrying out solid-liquid separation to obtain a liquid phase I and a 43g solid phase I;
(3) nutrient regulation: mixing the liquid phase I with a proper amount of additives, concentrating and drying to obtain a calcium (ammonium) nitrate fertilizer;
(4) secondary acidolysis: mixing the solid phase I with 41g of sulfuric acid solution with the concentration of 60 wt%, and reacting at 60 ℃ for 0.5h to obtain a mixed solution;
(5) solid-liquid separation: carrying out solid-liquid separation on the mixed solution obtained in the step (4) to obtain a solid phase II and a solution II, washing and filtering the solid phase II with hot water to obtain calcium sulfate dihydrate, wherein the washing water is used for preparing a sulfuric acid solution;
(6) neutralizing and removing impurities: neutralizing the liquid phase II with ammonia gas until the pH value of the solution is 4.0, and performing solid-liquid separation to obtain a liquid phase III and a solid phase III;
(7) concentrating and drying: evaporating, concentrating and drying the liquid phase III to obtain 26.5g water-soluble monoammonium phosphate containing P2O555.0 percent and N11.0 percent, and the indexes of the product HG/T5048-2016 water-soluble monoammonium phosphate.
Example 3
Phosphorus ore P was selected in this example2O5、CaO、MgO、Fe2O3、Al2O3、SiO2And F content of 19.42%, 27.99%, 0.44%, 1.51%, 3.36%, 41.44% and 1.45% respectively, and making into powdered rock phosphate. The specific process comprises the following steps:
(1) primary acidolysis: mixing phosphorus ore pulp containing 25% of water with a nitric acid solution, reacting for 0.5h at 70 ℃ to obtain a solid-liquid mixture, and carrying out solid-liquid separation to obtain an acid insoluble substance and a liquid phase; wherein, the ground phosphate rock is 100g, and the 50 wt% nitric acid solution is 161 g; wherein the mass of the acidolysis solution is 235.5g, and the P content of the acidolysis solution2O5The content is 8 percent, and the content of CaO is 11.5 percent;
(2) neutralizing: neutralizing the liquid phase obtained in the step (1) by ammonia until the pH value of the solution is 6.8; then carrying out solid-liquid separation to obtain a liquid phase I and 44g of a solid phase I;
(3) nutrient regulation: mixing the liquid phase I with a proper amount of additives, concentrating and drying to obtain a calcium (ammonium) nitrate fertilizer;
(4) secondary acidolysis: mixing the solid phase I with 50.5g of 50 wt% sulfuric acid solution, and reacting at 70 ℃ for 0.5 h; obtaining a mixed solution;
(5) solid-liquid separation: carrying out solid-liquid separation on the mixed solution obtained in the step (4) to obtain a solid phase II and a solution II, washing and filtering the solid phase II with hot water to obtain calcium sulfate dihydrate, wherein the washing water is used for preparing a sulfuric acid solution;
(6) neutralizing and removing impurities: neutralizing the liquid phase II with ammonia gas until the pH value of the solution is 4.1, and performing solid-liquid separation to obtain a liquid phase III and a solid phase III;
(7) concentrating and drying: evaporating the liquid phase III, concentrating, and drying27.3g of water-soluble monoammonium phosphate containing P was obtained2O556.0 percent and N11.5 percent, and the indexes of the product HG/T5048-2016 water-soluble monoammonium phosphate.
Example 4
Phosphorus ore P was selected in this example2O5、CaO、MgO、Fe2O3、Al2O3、SiO2And the contents of F are 26.70%, 41.53%, 2.34%, 0.60%, 0.53%, 19.75% and 2.50% respectively, and the ground phosphate rock is prepared. The specific process comprises the following steps:
(1) primary acidolysis: mixing the phosphorus ore pulp without water content with a nitric acid solution, reacting for 1.2h at 60 ℃ to obtain a solid-liquid mixture, and carrying out solid-liquid separation to obtain an acid insoluble substance and a liquid phase; wherein, the ground phosphate rock is 100g, and the 30 wt% nitric acid solution is 330 g; wherein the mass of the acidolysis solution is 399g, and the mass of the acidolysis solution is P2O56.5 percent of CaO and 10.1 percent of CaO;
(2) neutralizing: neutralizing the liquid phase obtained in the step (1) by using ammonium carbonate until the pH value of the solution is 7.3; then carrying out solid-liquid separation to obtain a liquid phase I and 61.5g of a solid phase I;
(3) nutrient regulation: mixing the liquid phase I with a proper amount of additives, concentrating and drying to obtain a calcium (ammonium) nitrate fertilizer;
(4) secondary acidolysis: mixing the solid phase I with 117g of 30 wt% sulfuric acid solution, and reacting at 60 ℃ for 0.5 h; obtaining a mixed solution;
(5) solid-liquid separation: separating the solid and liquid obtained in the step (4) to obtain a solid phase II and a solution II, washing and filtering the solid phase II with hot water to obtain calcium sulfate dihydrate, wherein the washing water is used for preparing a sulfuric acid solution;
(6) neutralizing and removing impurities: neutralizing the liquid phase II with liquid ammonia until the pH value of the solution is 4.4, and performing solid-liquid separation to obtain a liquid phase III and a solid phase III;
(7) concentrating and drying: evaporating, concentrating and drying the liquid phase III to obtain 37.3g water-soluble monoammonium phosphate containing P2O560.9 percent, contains 11.8 percent of N, and meets the indexes HG/T4133-2010 industrial monoammonium phosphate 2016 of water-soluble monoammonium phosphate.
Example 5
Phosphorus ore P was selected in this example2O5、CaO、MgO、Fe2O3、Al2O3、SiO2And F content of 30.41%, 41.30%, 1.48%, 1.94%, 1.03%, 9.93% and 2.99% respectively, and making into powdered rock phosphate. The specific process comprises the following steps:
(1) primary acidolysis: mixing phosphoric ore pulp with the water content of 40% and a nitric acid solution, reacting for 2 hours at the temperature of 30 ℃ to obtain a solid-liquid mixture, and carrying out solid-liquid separation to obtain an acid insoluble substance and a liquid phase; wherein, the ground phosphate rock is 100g, and the 40 wt% nitric acid solution is 310 g; wherein the mass of the acidolysis solution is 455.5g, and the P content of the acidolysis solution2O56.6 percent of CaO and 9.5 percent of CaO;
(2) neutralizing: neutralizing the liquid phase obtained in the step (1) by using ammonium carbonate until the pH value of the solution is 7.0; then carrying out solid-liquid separation to obtain a liquid phase I and a solid phase I of 72.2 g;
(3) nutrient regulation: mixing the liquid phase I with a proper amount of additives, concentrating and drying to obtain a calcium (ammonium) nitrate fertilizer;
(4) secondary acidolysis: mixing the solid phase I with 103g of 40 wt% sulfuric acid solution, and reacting at 30 ℃ for 0.5 h; obtaining a mixed solution;
(5) solid-liquid separation: separating the solid and liquid obtained in the step (4) to obtain a solid phase II and a solution II, washing and filtering the solid phase II with hot water to obtain calcium sulfate dihydrate, wherein the washing water is used for preparing a sulfuric acid solution;
(6) neutralizing and removing impurities: neutralizing the liquid phase II with ammonia gas until the pH value of the solution is 4.5, and performing solid-liquid separation to obtain a liquid phase III and a solid phase III;
(7) concentrating and drying: evaporating, concentrating and drying the liquid phase III to obtain 43.8g ammonium phosphate containing P2O561.0 percent and N11.8 percent, and the indexes of the product HG/T5048-2016 (water-soluble monoammonium phosphate) and meet HG/T4133-2010 (industrial monoammonium phosphate).
Claims (10)
1. The production method of the water-soluble monoammonium phosphate is characterized by comprising the following steps:
a. mixing nitric acid and phosphorite, reacting for 0.5-2 h at 30-70 ℃, and performing solid-liquid separation to obtain acidolysis solution;
b. neutralizing the acidolysis solution until the pH value is 6.5-8, and performing solid-liquid separation to obtain a solid phase I and a liquid phase I;
c. mixing the solid phase I with a sulfuric acid solution, reacting for 0.3-2 h at 30-70 ℃, and carrying out solid-liquid separation to obtain a solid phase II and a liquid phase II; neutralizing the liquid phase II until the pH value is 4.0-4.5, and then carrying out solid-liquid separation to obtain a solid phase III and a liquid phase III; wherein the liquid phase III is water-soluble monoammonium phosphate.
2. The method for producing water-soluble monoammonium phosphate according to claim 1, wherein in step c, the liquid phase II is neutralized to pH 4.1-4.5.
3. The method for producing water-soluble monoammonium phosphate according to claim 1 or 2, wherein in step a, the phosphate ore is in powder or slurry form, and the concentration of nitric acid is 30-70 wt% based on the water content in the phosphate ore being 0-40 wt%.
4. The method for producing the water-soluble monoammonium phosphate according to claim 1 or 2, wherein in the step a, the amount of the nitric acid is 0.9-1.2 times of the theoretical acid consumption of complete reaction of the phosphate ore; preferably, the dosage of the nitric acid is 0.9-1.1 times of the theoretical acid consumption of the complete reaction of the phosphorite.
5. The method for producing water-soluble monoammonium phosphate according to claim 1 or 2, wherein in step a, solid-liquid separation is carried out in two steps, wherein the liquid after the solid-liquid separation is subjected to sedimentation separation and then to filtration separation.
6. The method for producing a water-soluble monoammonium phosphate according to claim 1 or 2, wherein in step b, the neutralization is performed by using a basic neutralizing agent; preferably, the alkaline neutralizing agent is at least one of gas ammonia, ammonia water, limestone, lime milk, ammonium carbonate and ammonium bicarbonate; further preferably, the alkaline neutralizing agent is calcium carbonate, ammonia and milk of lime.
7. The method for producing water-soluble monoammonium phosphate according to claim 1 or 2, wherein in step c, the concentration of the sulfuric acid solution is 30-60 wt%; the dosage of the sulfuric acid solution is 0.9-1.2 times of the theoretical acid consumption of the complete reaction of the solid phase I; preferably, the dosage of the sulfuric acid solution is 0.95 to 1.05 times of the theoretical acid consumption of the complete reaction of the solid phase I.
8. The method for producing a water-soluble monoammonium phosphate according to claim 1 or 2, wherein the neutralizing agent used for neutralizing the liquid phase II in step c is ammonia gas or liquid ammonia.
9. The method for producing water-soluble monoammonium phosphate according to claims 1-8, wherein the liquid phase III is processed into solid water-soluble monoammonium phosphate; preferably, the liquid phase III is evaporated, concentrated and dried to obtain solid water-soluble monoammonium phosphate.
10. The production method of the water-soluble monoammonium phosphate according to claim 1 or 2, characterized in that the liquid phase I is added with a substance containing nutrient elements to adjust product nutrients, and the calcium nitrate fertilizer or the calcium ammonium nitrate fertilizer is obtained through evaporation, concentration and drying; preferably, the nutrient element-containing substance is at least one of ammonia, ammonium nitrate or calcium nitrate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2020104418074 | 2020-05-22 | ||
| CN202010441807 | 2020-05-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111533099A true CN111533099A (en) | 2020-08-14 |
| CN111533099B CN111533099B (en) | 2021-12-07 |
Family
ID=71968939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010455228.5A Active CN111533099B (en) | 2020-05-22 | 2020-05-26 | Production method of water-soluble monoammonium phosphate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111533099B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116177507A (en) * | 2023-02-22 | 2023-05-30 | 中化农业（临沂）研发中心有限公司 | Method for preparing ammonium phosphate by utilizing monoammonium phosphate neutralization slag and application thereof |
| CN116477654A (en) * | 2023-03-31 | 2023-07-25 | 湖北鄂中生态工程股份有限公司 | Harmless treatment method of phosphogypsum |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1003004A (en) * | 1962-04-11 | 1965-09-02 | California Research Corp | Hight analysis complex fertilizer preparation |
| GB1082395A (en) * | 1964-03-21 | 1967-09-06 | Stamicarbon | Process of preparing water-soluble phosphates |
| CN1032430A (en) * | 1987-10-06 | 1989-04-19 | 挪威海德罗公司 | The purification process of the dissolved calcium nitrate solution of from the mixture of the rock phosphorite gained of nitric acid dissolve, telling |
| CN1113881A (en) * | 1994-06-01 | 1995-12-27 | 门伟 | Producing method for monoammonium phosphate |
| CN101486595A (en) * | 2009-02-25 | 2009-07-22 | 天脊煤化工集团股份有限公司 | Technological process for producing high concentration nitric-phosphate fertilizer |
| CN102126740A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing byproduct gypsum of niter-sulfur-based compound fertilizer by decomposing phosphorite with nitric acid |
| CN102126741A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing nitro/S-based compound fertilizer and coproducing plaster |
| CN104229764A (en) * | 2014-09-01 | 2014-12-24 | 云南云天化国际化工有限公司 | Method for continuously producing water-soluble monoammonium phosphate by using wet-process phosphoric acid |
| CN106380232A (en) * | 2016-08-19 | 2017-02-08 | 贵州芭田生态工程有限公司 | A nitrogen-phosphorous composite fertilizer and a preparing method thereof |
| US20190322530A1 (en) * | 2016-06-28 | 2019-10-24 | Prayon Technologies | Method for the preparation of calcium monohydrogen phosphate |
-
2020
- 2020-05-26 CN CN202010455228.5A patent/CN111533099B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1003004A (en) * | 1962-04-11 | 1965-09-02 | California Research Corp | Hight analysis complex fertilizer preparation |
| GB1082395A (en) * | 1964-03-21 | 1967-09-06 | Stamicarbon | Process of preparing water-soluble phosphates |
| CN1032430A (en) * | 1987-10-06 | 1989-04-19 | 挪威海德罗公司 | The purification process of the dissolved calcium nitrate solution of from the mixture of the rock phosphorite gained of nitric acid dissolve, telling |
| CN1113881A (en) * | 1994-06-01 | 1995-12-27 | 门伟 | Producing method for monoammonium phosphate |
| CN101486595A (en) * | 2009-02-25 | 2009-07-22 | 天脊煤化工集团股份有限公司 | Technological process for producing high concentration nitric-phosphate fertilizer |
| CN102126740A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing byproduct gypsum of niter-sulfur-based compound fertilizer by decomposing phosphorite with nitric acid |
| CN102126741A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing nitro/S-based compound fertilizer and coproducing plaster |
| CN104229764A (en) * | 2014-09-01 | 2014-12-24 | 云南云天化国际化工有限公司 | Method for continuously producing water-soluble monoammonium phosphate by using wet-process phosphoric acid |
| US20190322530A1 (en) * | 2016-06-28 | 2019-10-24 | Prayon Technologies | Method for the preparation of calcium monohydrogen phosphate |
| CN106380232A (en) * | 2016-08-19 | 2017-02-08 | 贵州芭田生态工程有限公司 | A nitrogen-phosphorous composite fertilizer and a preparing method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 纳比耶夫: "《硝酸磷肥》", 30 September 1980 * |
| 鄢笑非等: "盐酸湿法磷酸生产工艺优化 ", 《武汉工程大学学报》 * |
| 马凯等: "硝酸分解磷矿生产磷酸氢钙最佳反应条件的实验研究 ", 《磷肥与复肥》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116177507A (en) * | 2023-02-22 | 2023-05-30 | 中化农业（临沂）研发中心有限公司 | Method for preparing ammonium phosphate by utilizing monoammonium phosphate neutralization slag and application thereof |
| CN116477654A (en) * | 2023-03-31 | 2023-07-25 | 湖北鄂中生态工程股份有限公司 | Harmless treatment method of phosphogypsum |
| CN116477654B (en) * | 2023-03-31 | 2024-05-31 | 湖北鄂中生态工程股份有限公司 | Harmless treatment method of phosphogypsum |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111533099B (en) | 2021-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105197905B (en) | Extract the production method of phosphorus ore coproduction feed-level calcium biphosphate and technical grade phosphorus ammonium | |
| CN107814370B (en) | Circulating environment-friendly process method for preparing phosphate concentrate, product and application thereof | |
| CN103072963B (en) | Method for producing potassium dihydrogen phosphate through wet-process phosphoric acid | |
| CN102351591A (en) | Method for highly water-soluble nitrophosphate fertilizer production through decomposition of rare earth-containing phosphate rock by nitric acid and for rare earth recovery | |
| CN111533099B (en) | Production method of water-soluble monoammonium phosphate | |
| CN104445300A (en) | Method of preparing magnesium hydroxide and calcium carbonate and separating out phosphorus ores by taking phosphate tailings as raw materials through ammonia circulation process | |
| CN101337657A (en) | Process for disassembling phosphate ore by mixed acid and coproducing potassium dihydrogen phosphate, hydrogen phosphate and combined fertilizer | |
| CN107720713A (en) | A kind of method that phosphoric acid by wet process prepares ammonium dihydrogen phosphate co-production potassium dihydrogen phosphate | |
| CN111592014A (en) | Method and system device for preparing potassium sulfate, calcium carbonate and ammonium chloride from phosphogypsum | |
| CN113277885A (en) | Resource utilization method of phosphoric acid residues | |
| CN115092901B (en) | Method for preparing battery-grade ferric phosphate by decomposing phosphorite with nitric acid | |
| CN107827113B (en) | Method for recovering fluorine in industrial monoammonium phosphate neutralized slag slurry | |
| CN107473775B (en) | Method for recovering phosphorus and fluorine in phosphoric acid concentrated slag acid and co-producing low-fluorine water-soluble fertilizer | |
| CN103864039B (en) | The method of phosphoric acid defluorination coproduction PHOSPHORIC ACID TECH.GRADE ammonium dihydrogen and feed-grade calcium phosphate salt | |
| CN101439866B (en) | Method for producing ammonium nitrate phosphate by decomposing phosphate ore using ammonium bisulfate and nitric acid | |
| CN110217769B (en) | Method for producing calcium ammonium nitrate byproduct feed-grade DCP | |
| CN116062721B (en) | Method for utilizing all elements of phosphate tailings | |
| CN111517832B (en) | Separation method of P, Ca in medium-low grade phosphate ore and method for producing fertilizer | |
| CN104828799A (en) | Process of producing feed-grade calcium dihydrogen phosphate through phosphoric acid circulation impurity removal method | |
| EP3495323B1 (en) | A process for obtaining a soluble phosphate fraction from phosphate containing ash | |
| CN116199536A (en) | Preparation method of acidic water-soluble composite phosphate | |
| CN107954406B (en) | Method for producing high-quality industrial diammonium phosphate by using composite salt purification wet-process phosphoric acid | |
| WO2019028957A1 (en) | Method for producing calcium phosphate and calcium sulfate by using hydrochloric acid and phosphate ore | |
| CN112758937B (en) | Method for preparing potassium fluosilicate and NPK compound fertilizer from associated phosphate-potassium ore | |
| CN113213444A (en) | Production method for decomposing phosphorite by using unconventional nitric acid and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |