Potassium preparation process by glauber method

Abstract

A potassium preparation process by the glauber method includes 1, conversion of a first stage, namely converting thenardite and potassium chloride with water and / or mother liquor material containing potassium sulfate, performing solid-liquor separation, and obtaining the aphthitalite and the conversion mother liquor of the first stage; 2, evaporation of a first stage, namely performing the evaporation of the first stage on the conversion mother liquor of the first stage, performing solid-liquor separation, and obtaining the sodium high temperature salt and the evaporation mother liquor of the first stage; 3, evaporation of a second stage, namely performing the evaporation of the second stage on the evaporation mother liquor of the first stage, performing solid-liquor separation, and obtaining aphthitalite / sodium high temperature mixed salt and the evaporation mother liquor of the second stage; 4, physically separating the mixed salt to obtain aphthitalite and sodium; 5, conversion of a second stage, namely converting the aphthitalite and sodium and water and / or mother liquor material containing potassium sulfate, performing solid-liquor separation, and obtaining the potassium sulfate coarse product and the conversion mother liquor of the second stage; 6, washing and drying to obtain the potassium sulfate product. By the aid of the method, the product separating purity is high, the quantity of mother liquor is small, energy consumption and cost are low, the content of K2O of the potassium sulfate product is of 51.3%, and the agricultural-use first-class potassium sulfate standard can be met.

Description

technical field

[0001] The invention relates to a process for preparing potassium sulfate, in particular to a process for preparing potassium sulfate by the Glauber's salt method. Background technique

[0002] Potassium sulfate is an important chlorine-free potassium fertilizer, and the agricultural demand is very strong.

[0003] At present, 50% of potassium sulfate fertilizer in the world comes from minerals, and about 40% of potassium sulfate is obtained by converting potassium chloride and sulfuric acid or sulfate. Glauber's salt conversion method is also the most researched and most in-depth method of preparing potassium sulfate so far. . In my country, the proven reserves of Glauber's salt mineral resources have reached about 20 billion tons (in terms of anhydrous sodium sulfate), ranking first in the world, and are distributed in 14 provinces and regions in my country, among which Qinghai, Sichuan, Inner Mongolia, Hunan, Yunnan, The six provinces of Xinjiang are the ...

Examples

Embodiment 1

[0038] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 85wt%) and potassium chloride and water are mixed and proportioned until the mass concentration of potassium in the system is 10.19wt%, and the mass concentration of sulfate is 12.72wt%. Stir, and at 25°C, the conversion reaction takes 2h to precipitate potassium After Glauber's salt, solid-liquid separation is carried out to obtain potassium Glauber's salt and a transformation mother liquor;

[0039] (2) One-stage evaporation: The first-stage transformation mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 21.4wt% of the first-stage transformation mother liquor mass at 120°C to obtain sodium chloride high-temperature salt and one-stage evaporation Mother liquor;

[0040] (3) Two-stage evaporation: After the first-stage evaporation mother liquor obtained in step (2) is evaporated at 110°C, after the second-stage evapo...

Embodiment 2

[0047] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 92.4wt%) and potassium chloride and water and embodiment 1 step (3) obtained cooled two-stage evaporation mother liquor, step (5) obtained two-stage transformation mother liquor, and the repulping washing water of by-product sodium chloride is mixed Batching, until the mass concentration of potassium element in the system is 10.29wt%, the mass concentration of sulfate radical is 10.01wt%, stir, at 30 ℃, after conversion reaction 1h precipitates potassium mirabilite, carry out solid-liquid separation, obtain potassium mirabilite and a section Transform mother liquor;

[0048] (2) One-stage evaporation: The one-stage transformation mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 26.13wt% of the first-stage transformation mother liquor mass at 110°C to obtain sodium chloride high-temperature salt and one-stage evaporati...

Embodiment 3

[0056] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 98.5wt%) and potassium chloride and water and embodiment 2 step (3) obtained cooled two-stage evaporation mother liquor, step (5) obtained two-stage transformation mother liquor, by-product sodium chloride repulping washing water is mixed Batching, until the mass concentration of potassium element in the system is 10.85wt%, the mass concentration of sulfate radical is 11.64wt%, stir, at 25 ℃, after conversion reaction 3h precipitates potassium mirabilite, carry out solid-liquid separation, obtain potassium mirabilite and a section Transform mother liquor;

[0057] (2) One-stage evaporation: The one-stage conversion mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 24.7wt% of the first-stage transformation mother liquor mass at 100°C to obtain sodium chloride high-temperature salt and one-stage evaporation Mother liquo...

technical field

[0001] The invention relates to a process for preparing potassium sulfate, in particular to a process for preparing potassium sulfate by the Glauber's salt method. Background technique

[0002] Potassium sulfate is an important chlorine-free potassium fertilizer, and the agricultural demand is very strong.

[0003] At present, 50% of potassium sulfate fertilizer in the world comes from minerals, and about 40% of potassium sulfate is obtained by converting potassium chloride and sulfuric acid or sulfate. Glauber's salt conversion method is also the most researched and most in-depth method of preparing potassium sulfate so far. . In my country, the proven reserves of Glauber's salt mineral resources have reached about 20 billion tons (in terms of anhydrous sodium sulfate), ranking first in the world, and are distributed in 14 provinces and regions in my country, among which Qinghai, Sichuan, Inner Mongolia, Hunan, Yunnan, The six provinces of Xinjiang are the ...

Examples

Embodiment 1

[0038] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 85wt%) and potassium chloride and water are mixed and proportioned until the mass concentration of potassium in the system is 10.19wt%, and the mass concentration of sulfate is 12.72wt%. Stir, and at 25°C, the conversion reaction takes 2h to precipitate potassium After Glauber's salt, solid-liquid separation is carried out to obtain potassium Glauber's salt and a transformation mother liquor;

[0039] (2) One-stage evaporation: The first-stage transformation mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 21.4wt% of the first-stage transformation mother liquor mass at 120°C to obtain sodium chloride high-temperature salt and one-stage evaporation Mother liquor;

[0040] (3) Two-stage evaporation: After the first-stage evaporation mother liquor obtained in step (2) is evaporated at 110°C, after the second-stage evapo...

Embodiment 2

[0047] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 92.4wt%) and potassium chloride and water and embodiment 1 step (3) obtained cooled two-stage evaporation mother liquor, step (5) obtained two-stage transformation mother liquor, and the repulping washing water of by-product sodium chloride is mixed Batching, until the mass concentration of potassium element in the system is 10.29wt%, the mass concentration of sulfate radical is 10.01wt%, stir, at 30 ℃, after conversion reaction 1h precipitates potassium mirabilite, carry out solid-liquid separation, obtain potassium mirabilite and a section Transform mother liquor;

[0048] (2) One-stage evaporation: The one-stage transformation mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 26.13wt% of the first-stage transformation mother liquor mass at 110°C to obtain sodium chloride high-temperature salt and one-stage evaporati...

Embodiment 3

[0056] (1) One stage transformation: anhydrous Glauber's salt (Na 2 SO 4 Content is 98.5wt%) and potassium chloride and water and embodiment 2 step (3) obtained cooled two-stage evaporation mother liquor, step (5) obtained two-stage transformation mother liquor, by-product sodium chloride repulping washing water is mixed Batching, until the mass concentration of potassium element in the system is 10.85wt%, the mass concentration of sulfate radical is 11.64wt%, stir, at 25 ℃, after conversion reaction 3h precipitates potassium mirabilite, carry out solid-liquid separation, obtain potassium mirabilite and a section Transform mother liquor;

[0057] (2) One-stage evaporation: The one-stage conversion mother liquor obtained in step (1) is subjected to solid-liquid separation after one-stage evaporation of water equivalent to 24.7wt% of the first-stage transformation mother liquor mass at 100°C to obtain sodium chloride high-temperature salt and one-stage evaporation Mother liquo...