Separation method of P and Ca in medium-low-grade phosphorite and method for producing fertilizer

Abstract

The invention relates to a method for separating P and Ca in medium-low-grade phosphorite and a method for producing fertilizer, and belongs to the technical field of phosphorite cleaning processing and utilization. The method for separating P and Ca in medium-low-grade phosphorite comprises the following steps: (1) mixing phosphorite with a nitric acid solution, reacting at 30-70 DEG C for 0.5-2hours, and carrying out solid-liquid separation to obtain an acid-insoluble substance and an acidolysis clear solution; (2) neutralizing the acidolysis clear solution, and controlling the pH value ofthe solution to be greater than or equal to 3.5 and less than or equal to 6.5; carrying out solid-liquid separation to obtain a solid phase I and a liquid phase I; (3) mixing the solid phase I with anitric acid solution, and reacting at 30-70 DEG C for 0.3-2 hours to obtain a secondary acidolysis solution; (4) cooling the secondary acidolysis solution to -10 DEG C to 0 DEG C for crystallization;after crystallization is completed, carrying out solid-liquid separation to obtain a solid phase II and a liquid phase II. According to the process, the separation rate of P and Ca in the medium-low-grade phosphorite is greatly increased, the utilization rate of resources such as P and Ca is increased, and a new technical route is opened up for processing the medium-low-grade phosphorite by a nitric acid method.

Description

technical field

[0001] The invention relates to a method for separating P and Ca in medium and low-grade phosphate rocks and a method for producing fertilizers, and belongs to the technical field of clean processing and utilization of phosphate rocks. Background technique

[0002] Phosphate rock resources are an important strategic resource of the country and the material basis of the phosphorus chemical industry. They are non-renewable. my country is rich in phosphor rock resources, but more than 80% of them are medium and low-grade phosphate rocks that are difficult to use directly.

[0003] Phosphate rock processing and utilization mainly include thermal and wet processes, and wet processes mainly include hydrochloric acid method, sulfuric acid method, and nitric acid method. The vast majority of phosphate rock processing enterprises in my country adopt the acid wet process. For every ton of phosphoric acid produced by the sulfuric acid process (in P 2 o 5 Total) will ...

Examples

Example Embodiment

[0081] Example 1

[0082] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F is 27.96%, 41.30%, 1.48%, 1.94%, 1.03%, 9.93%, 2.99%, respectively, to make phosphate rock powder. The specific process is as follows:

[0083] (1) Primary acid hydrolysis: Mix 21% phosphate ore slurry with nitric acid solution, react at 50°C for 1.5 hours to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphorus The mineral powder is 100g, the nitric acid solution is 212g, the concentration is 50wt%; the mass of the acid hydrolyzate is 315.4g, and the P 2 O 5 The content is 8.7%, and the CaO content is 12.8%;

[0084] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonia to the solution pH=3.7; then perform solid-liquid separation to obtain liquid phase I and 63 g of solid phase I;

[0085] (3) Secondary acid hydrolysis: Mix solid ...

Example Embodiment

[0089] Example 2

[0090] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F is 18.12%, 29.46%, 2.74%, 1.63%, 3.73%, 34.53%, 1.62%, respectively, to make phosphate rock powder. The specific process is as follows:

[0091] (1) Primary acid hydrolysis: Mix phosphate rock slurry with a water content of 40% and nitric acid solution, react at 60°C for 1 hour to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphate rock The powder is 100g; the nitric acid solution is 145.5g, the concentration is 70wt%; the mass of the acid hydrolysis solution is 266.7g, and the P in the acid hydrolysis solution 2 O 5 The content is 6.7%, and the content of CaO is 10.8%;

[0092] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonium carbonate to the solution pH=3.6; then perform solid-liquid separation to obtain liquid phase I an...

Example Embodiment

[0097] Example 3

[0098] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F are respectively 19.42%, 27.99%, 0.44%, 1.51%, 3.36%, 41.44%, 1.45% to make phosphate rock powder. The specific process is as follows:

[0099] (1) First-level acid hydrolysis: mix the non-aqueous phosphate rock slurry and nitric acid solution, react at 70°C for 0.5h to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphate rock powder is 100g; 241g nitric acid solution with a concentration of 30wt%; the mass of the acid hydrolysis solution is 282g, and the content of the acid hydrolysis solution is P 2 O 5 The content is 6.6%, and the content of CaO is 9.5%;

[0100] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonia to the solution pH=4.4; then perform solid-liquid separation to obtain liquid phase I and 43.8 g of solid phase I...

technical field

[0001] The invention relates to a method for separating P and Ca in medium and low-grade phosphate rocks and a method for producing fertilizers, and belongs to the technical field of clean processing and utilization of phosphate rocks. Background technique

[0002] Phosphate rock resources are an important strategic resource of the country and the material basis of the phosphorus chemical industry. They are non-renewable. my country is rich in phosphor rock resources, but more than 80% of them are medium and low-grade phosphate rocks that are difficult to use directly.

[0003] Phosphate rock processing and utilization mainly include thermal and wet processes, and wet processes mainly include hydrochloric acid method, sulfuric acid method, and nitric acid method. The vast majority of phosphate rock processing enterprises in my country adopt the acid wet process. For every ton of phosphoric acid produced by the sulfuric acid process (in P 2 o 5 Total) will ...

Examples

Example Embodiment

[0081] Example 1

[0082] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F is 27.96%, 41.30%, 1.48%, 1.94%, 1.03%, 9.93%, 2.99%, respectively, to make phosphate rock powder. The specific process is as follows:

[0083] (1) Primary acid hydrolysis: Mix 21% phosphate ore slurry with nitric acid solution, react at 50°C for 1.5 hours to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphorus The mineral powder is 100g, the nitric acid solution is 212g, the concentration is 50wt%; the mass of the acid hydrolyzate is 315.4g, and the P 2 O 5 The content is 8.7%, and the CaO content is 12.8%;

[0084] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonia to the solution pH=3.7; then perform solid-liquid separation to obtain liquid phase I and 63 g of solid phase I;

[0085] (3) Secondary acid hydrolysis: Mix solid ...

Example Embodiment

[0089] Example 2

[0090] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F is 18.12%, 29.46%, 2.74%, 1.63%, 3.73%, 34.53%, 1.62%, respectively, to make phosphate rock powder. The specific process is as follows:

[0091] (1) Primary acid hydrolysis: Mix phosphate rock slurry with a water content of 40% and nitric acid solution, react at 60°C for 1 hour to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphate rock The powder is 100g; the nitric acid solution is 145.5g, the concentration is 70wt%; the mass of the acid hydrolysis solution is 266.7g, and the P in the acid hydrolysis solution 2 O 5 The content is 6.7%, and the content of CaO is 10.8%;

[0092] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonium carbonate to the solution pH=3.6; then perform solid-liquid separation to obtain liquid phase I an...

Example Embodiment

[0097] Example 3

[0098] Phosphate rock P is used in this example 2 O 5 , CaO, MgO, Fe 2 O 3 , Al 2 O 3 , SiO 2 The content of F and F are respectively 19.42%, 27.99%, 0.44%, 1.51%, 3.36%, 41.44%, 1.45% to make phosphate rock powder. The specific process is as follows:

[0099] (1) First-level acid hydrolysis: mix the non-aqueous phosphate rock slurry and nitric acid solution, react at 70°C for 0.5h to obtain a solid-liquid mixture, and obtain acid-insoluble matter and acid hydrolysis solution after solid-liquid separation; among them, phosphate rock powder is 100g; 241g nitric acid solution with a concentration of 30wt%; the mass of the acid hydrolysis solution is 282g, and the content of the acid hydrolysis solution is P 2 O 5 The content is 6.6%, and the content of CaO is 9.5%;

[0100] (2) Neutralization: neutralize the liquid phase obtained in step (1) with ammonia to the solution pH=4.4; then perform solid-liquid separation to obtain liquid phase I and 43.8 g of solid phase I...

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