阅读说明：本技术 生产结晶硫酸钾镁肥工艺 (Process for producing crystal potassium magnesium sulfate fertilizer ) 是由 汤继纯 于 2019-10-22 设计创作，主要内容包括：一种生产结晶硫酸钾镁肥工艺,包括以下步骤：步骤1、将盐田中收集的低钠矿与硫酸钾二系母液混合并在常温下分解30分钟；步骤2、将分解后的混合物经过过滤得到软钾镁矾；步骤3、将软钾镁矾与淡水混合并在常温下分解30分钟；步骤4、将步骤3形成的混合物经过过滤得到结晶状钾镁肥,新型的工艺整个过程无尾固排放,收率高,不添加浮选药剂,产品绿色环保,生产成本减少50％以上,可做有机肥使用,而且工艺流程简单,设备少,流程短,用人少,易控制。(A process for producing a crystallized potash magnesium sulphate fertilizer comprises the following steps: step 1, mixing low-sodium ores collected in a salt pan with potassium sulfate secondary mother liquor and decomposing for 30 minutes at normal temperature; step 2, filtering the decomposed mixture to obtain schoenite; step 3, mixing schoenite with fresh water and decomposing for 30 minutes at normal temperature; and 4, filtering the mixture formed in the step 3 to obtain the crystallized potassium-magnesium fertilizer, wherein the whole process of the novel process has no tail solid discharge, the yield is high, no flotation reagent is added, the product is green and environment-friendly, the production cost is reduced by more than 50%, and the crystallized potassium-magnesium fertilizer can be used as an organic fertilizer.)

1. A process for producing a crystallized potash magnesium sulphate fertilizer is characterized by comprising the following steps:

Step 1, mixing low-sodium ores collected in a salt pan with potassium sulfate secondary mother liquor and decomposing for 30 minutes at normal temperature;

Step 2, filtering the decomposed mixture to obtain schoenite;

Step 3, mixing schoenite with fresh water and decomposing for 30 minutes at normal temperature;

And 4, filtering the mixture formed in the step 3 to obtain the crystalline potash magnesium fertilizer.

2. The process for producing the crystalline potash magnesium sulphate fertilizer of claim 1, wherein the low sodium ore in step 1 is prepared by mixing old brine and frozen mango brine with brine to prepare 16-point brine at 15 ℃, and drying in the sun in a salt pan.

3. The process for producing the crystalline potash magnesium sulphate fertilizer of claim 1, wherein the solid-to-liquid ratio of the potassium sulphate secondary mother liquor and the carnallite in the step 1 is 1: 1.

4. the process for producing the crystalline potash magnesium sulphate fertilizer of claim 1, wherein four decomposition tanks are used in the decomposition process.

5. The process for producing crystalline potash magnesium sulphate fertilizer as claimed in claim 1, wherein the filtering process employs a belt filter.

6. the process for producing the crystalline potash magnesium sulphate fertilizer as claimed in claim 1, wherein the secondary mother liquor of potassium sulphate contains the following components in percentage by mass: k⁺ 7.8、Na⁺ 0.62、Mg²⁺ 2.5、Cl^-11.87、SO₄ ^2- 4.75。

Technical Field

The invention relates to the technical field of salt chemical engineering, in particular to a process for producing a crystallized potassium magnesium sulfate fertilizer.

Background

Schoenite (abbreviated as Pic) has the formula: MgSO (MgSO)₄·K₂SO₄A·6H₂O is a high-quality fertilizer which can provide necessary nutrients such as potassium, magnesium, sulfur and the like for the growth of crops and is called a potash magnesium sulphate fertilizer. The potassium mixed salt is obtained by evaporating and drying in the sun from sulfate brine, and is a mixture containing minerals such as sylvite, carnallite, kainite, epsomite, halite and the like, the flotation method is generally adopted to prepare the picromerite in the world at present, namely, the potassium mixed salt ore prepared by carrying out sodium removal and drying on the magnesium sulfate brine is ground to form slurry, and the slurry is converted, floated and dehydrated picromerite is converted, tail liquid and tail slag are generated after the flotation by the method, so that the surrounding environment is polluted, the waste of raw materials is caused, and the influence of a flotation reagent on the environment is causedThe sound is also huge, so that the method does not meet the current market development trend.

Disclosure of Invention

The invention mainly solves the technical problem of providing a process for producing the crystallized potassium magnesium sulfate fertilizer, which is green and environment-friendly, has low production cost and less labor force.

In order to solve the technical problems, the invention provides a process for producing a crystallized potassium magnesium sulfate fertilizer, which comprises the following steps:

Step 1, mixing low-sodium ores collected in a salt pan with potassium sulfate secondary mother liquor and decomposing for 30 minutes at normal temperature;

step 2, filtering the decomposed mixture to obtain schoenite;

Step 3, mixing schoenite with fresh water and decomposing for 30 minutes at normal temperature;

and 4, filtering the mixture formed in the step 3 to obtain the crystalline potash magnesium fertilizer.

the improvement of the invention is that the low sodium ore in the step 1 is prepared by mixing old brine and frozen mango brine to prepare 16-point brine at 15 ℃ and drying the brine in the sun.

The improvement of the invention is that the solid-to-liquid ratio of the potassium sulfate secondary mother liquor and the carnallite in the step 1 is 1: 1.

The invention is improved in that the decomposition process adopts four decomposition tanks arranged side by side.

The invention is improved by adopting a belt filter in the filtering process.

The improvement of the invention is that the potassium sulfate secondary mother liquor contains the following components by mass percentage: k⁺7.8、Na⁺0.62、Mg²⁺2.5、Cl^-11.87、SO₄ ^2-4.75。

The invention has the beneficial effects that: the novel process has no tail solid emission in the whole process, high yield, no addition of a flotation reagent, green and environment-friendly products, production cost reduction of more than 50 percent, capability of being used as an organic fertilizer, simple process flow, less equipment, short flow, less manpower and easy control.

Drawings

FIG. 1 is a process flow diagram of the process for producing crystallized magnesium potassium sulfate fertilizer.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following description is made in conjunction with the embodiments.

First, some technical terms in the present invention are explained:

The term "old brine" in the invention is also called tail brine, and refers to brine obtained by naturally or artificially concentrating magnesium-containing brine, wherein the brine has the lowest KCL and NACL contents, contains a certain MgSO4, and is brine obtained by saturated precipitation of MgSO4 & 6H 2O.

the term "salt pan" in the present invention refers to an area for perfusing brine and producing salt by evaporation.

The term "frozen miscanthus" in the present invention refers to a process of naturally precipitating mirabilite from raw bittern in winter.

the term "blending" in the present invention refers to the process of mixing different brines with different stirring.

The term "carnallite" in the present invention has the chemical formula KCl MgCL₂·6H₂O, Car for short, which is a product separated out in the brine evaporation process.

The terms and the mass percentages of the components in the mixture are influenced by a plurality of factors such as temperature, atmospheric pressure, mining location and mining process, so that the components in different systems may have differences, and the invention cannot be exhaustive and is only illustrated by way of example, but the differences do not influence the implementation of the method and are also the technical content to be protected.

The invention provides a process for producing a crystallized potassium magnesium sulfate fertilizer, which specifically comprises the following steps:

step 1, mixing low-sodium ores collected in a salt pan with potassium sulfate secondary mother liquor and decomposing for 30 minutes at normal temperature;

The low-sodium ore is prepared by mixing old brine and frozen mango brine into brine at 15 ℃ to prepare 16-point brine, and drying the brine in a salt pan to prepare sylvite ore, wherein the potassium ion content of the material reaches 8 percent, and the low-sodium low-magnesium mineral is low in sodium;

In the decomposition process, a decomposition tank is adopted, specifically, 4 tanks are adopted for cyclic decomposition, and the potassium sulfate secondary mother liquor and the low sodium ore are mixed, and in addition, the solid-to-liquid ratio of the potassium sulfate secondary mother liquor to the carnallite is ensured to be 1: 1.

step 2, filtering the decomposed mixture to obtain schoenite;

in this example, a belt filter was used for filtration, and the crude Pic was obtained after filtration.

Step 3, mixing schoenite with fresh water and decomposing for 30 minutes at normal temperature;

Specifically, the crude Pic filtered out in step 2 is mixed with fresh water and decomposed, in this embodiment, the decomposition is performed by using a decomposition tank, preferably by using 4 decomposition tanks for cyclic decomposition, so that the decomposition of the whole Pic is more sufficient, and after about 30 minutes of decomposition, the Pic undergoes a crystallization reaction to form fine crystals.

And 4, filtering the mixture formed in the step 3 to obtain the crystalline precipitated potash magnesium fertilizer, wherein the crystalline precipitated potash magnesium fertilizer contains 6 crystal waters, and the product is easy to dissolve in water, convenient to apply, free of hardening after long-term storage, and convenient to store and transport

In this embodiment, the potassium sulfate secondary mother liquor contains the following components in percentage by mass: k⁺7.8、Na⁺0.62、Mg²⁺2.5、Cl^-11.87、SO₄ ^2-4.75。

The whole process steps are represented by the chemical formula:

salt pan sun-dried low-sodium ore +2M26 (potassium sulfate secondary mother liquor) → Pic + NaCl + H2O → Pic (crystalline)

The process has no tail solid discharge, high yield, no addition of flotation reagent, green and environment-friendly product, reduction of production cost by more than 50 percent, and can be used as organic fertilizer. The process flow is simple, the equipment is few, the flow is short, the manpower is few, and the process is easy to control.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.