A production method of potassium fluorosilicate

Abstract

The present invention discloses a method for producing potassium fluorosilicate. The process for generating potassium fluorosilicate in the present invention includes the following steps: 1) Refine fluosilicic acid and place it in a fluosilicic acid storage tank for standby; 2) Dissolve and remove impurities from potassium chloride to obtain a potassium chloride solution; 3) React the refined fluosilicic acid and the potassium chloride solution in a synthesis tank to obtain a potassium fluorosilicate crystal slurry, and then centrifuge and wash it with a centrifuge to obtain potassium fluorosilicate. The production method of potassium fluorosilicate in the present invention is simple, and can reasonably utilize the filtrate and filter residue generated during the production process, reducing the production cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of potassium fluorosilicate preparation, and particularly relates to a production method of potassium fluorosilicate. Background Art

[0002] Potassium fluorosilicate is used as an auxiliary agent for magnesium and aluminum smelting in the metallurgical industry, is used to manufacture potassium glass, optical glass, and opaque glass in the glass industry, is used to manufacture pesticides in the pesticide industry, is used to manufacture intermediates in the chemical industry, is used as an analytical reagent in analytical chemistry, and can also be used in aspects such as ceramic synthetic mica.

[0003] The patent with the application number CN202211275261.5 discloses a method for preparing potassium fluorosilicate from a fluorine-containing liquid. In this preparation method, the silicon slag is first treated, then the treated silicon slag is stirred and reacted with the fluorine-containing liquid, and then potassium salt is added to obtain potassium fluorosilicate. Although this method can prepare potassium fluorosilicate, the purity of the obtained potassium fluorosilicate is not high, which limits the application of potassium fluorosilicate in some fields. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a production method of potassium fluorosilicate.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A production method of potassium fluorosilicate includes the following steps,

[0007] Step S1: Add mother liquor, water, and potassium chloride into the potassium chloride dissolution tank, stir and mix evenly, then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 220 - 240 g / L, send it to the filter press for filtration, and then send the filtrate to the potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to the filter press for filtration again, and the filtrate after filtration is stored in the potassium chloride storage tank for standby;

[0008] Further, the dosage ratio of recycled mother liquor, water, and potassium chloride is 5 - 15m 3 : 10 - 30m 3 : 4.5 - 13.5 t.

[0009] Step S2: Pump the potassium chloride solution and refined fluosilicic acid to the potassium chloride metering tank and the fluosilicic acid metering tank for metering respectively, and then send the metered potassium chloride solution and refined fluosilicic acid into the synthesis tank through pipelines at the same time, and react at normal temperature and pressure for 1 h. After the reaction is completed, potassium fluorosilicate crystal slurry is obtained. The involved chemical equations are:

[0010] H 2 SiF 6+ 2KCl → K 2 SiF 6 ↓ + 2HCl

[0011] Furthermore, the dosages of potassium chloride solution and refined fluosilicic acid are 3 - 9 m 3 : 2.5 - 7.5 m 3 .

[0012] Step S3: Centrifuge the potassium fluosilicate crystal slurry in a centrifuge to separate the product and the mother liquor. The mother liquor is sent to the mother liquor storage tank for recycling to dissolve potassium chloride. The product is washed with clear water and centrifuged, and then sent to a single - cylinder drying rotary kiln for drying. The dried product is screened through a single - layer vibrating screen to distinguish qualified products from unqualified products. The unqualified products are centrifuged, washed and then added to the potassium chloride dissolution tank. The qualified products are packaged and formed by an automatic packaging machine, and potassium fluosilicate is obtained.

[0013] The refined fluosilicic acid is prepared by the following steps:

[0014] The raw fluosilicic acid with a concentration of 30 - 40% is pumped from the raw material storage tank to the fluosilicic acid blending tank, and then water is added to blend it into a concentration of 12%. After that, it is sent to a filter press for pressure filtration. The silicon - containing filter residue is returned to the blending tank for recycling, and the filtrate is sent to the fluosilicic acid storage tank for standby.

[0015] Advantages of the present invention:

[0016] The present invention relates to a production method of potassium fluosilicate. First, the fluosilicic acid is refined and placed in the fluosilicic acid storage tank for standby. Then, potassium chloride is dissolved and purified to obtain a potassium chloride solution. Finally, the refined fluosilicic acid and the potassium chloride solution are reacted in a synthesis tank to obtain a potassium fluosilicate crystal slurry, which is then centrifuged and washed by a centrifuge to obtain potassium fluosilicate.

[0017] The production method of potassium fluosilicate in the present invention is simple, and can reasonably utilize the filtrate and filter residue generated in the production process, reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a process flow chart of potassium fluosilicate production.

[0020] Figure 2 It is a process flow chart of fluosilicic acid refining. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0022] A method for producing potassium fluorosilicate includes the following steps:

[0023] Step S1: Add 5 m 3 mother liquor, 10 m 3 water and 4.5 t of potassium chloride into the potassium chloride dissolution tank, stir and mix evenly, then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 220 g / L, send it to the filter press for filtration, and then send the filtrate to the potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to the filter press for filtration again. The filtrate after filtration is stored in the potassium chloride storage tank for standby;

[0024] Step S2: Pump the potassium chloride solution and refined fluosilicic acid to the potassium chloride metering tank and the fluosilicic acid metering tank for metering respectively. Then, simultaneously send 3 m 3 of the metered potassium chloride solution and 2.5 m 3 of the refined fluosilicic acid into the synthesis tank through the pipeline and react for 1 h at normal temperature and pressure. After the reaction is completed, potassium fluorosilicate crystal slurry is obtained;

[0025] Step S3: Centrifuge the potassium fluorosilicate crystal slurry in a centrifuge to separate the product and the mother liquor. The mother liquor is sent to the mother liquor storage tank for recycling to dissolve potassium chloride. The product is washed with clear water and centrifuged, and then sent to a single-cylinder drying rotary kiln for drying. The dried product is screened through a single-layer vibrating screen to distinguish qualified products and unqualified products. The unqualified products are centrifuged, washed and then added to the potassium chloride dissolution tank. The qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluorosilicate.

[0026] The refined fluosilicic acid is prepared by the following steps:

[0027] Pump the raw fluosilicic acid with a concentration of 30% from the raw material storage tank to the fluosilicic acid blending tank, add water to blend it into a concentration of 12%, and then send it to the filter press for filtration. The silicon-containing filter residue is returned to the blending tank for recycling, and the filtrate is sent to the fluosilicic acid storage tank for standby. Embodiment

[0028] A method for producing potassium fluorosilicate includes the following steps:

[0029] Step S1: Add 10 m 3 mother liquor, 20 m3 Mix 15 m³ of water and 9 t of potassium chloride evenly, then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 230 g / L, send it to a filter press for pressure filtration. Then send the filtrate to a potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to a filter press for pressure filtration again. The filtrate after pressure filtration is stored in a potassium chloride storage tank for standby;

[0030] Step S2: Pump the potassium chloride solution and refined fluosilicic acid to a potassium chloride metering tank and a fluosilicic acid metering tank for metering respectively. Then simultaneously send the metered 6 m³ of potassium chloride solution and 5 m³ of refined fluosilicic acid into a synthesis tank through pipelines and react for 1 h under normal temperature and pressure. After the reaction is completed, potassium fluosilicate crystal slurry is obtained; 3 5 m³ of 3 Refined fluosilicic acid is prepared by the following steps:

[0031] Step S3: Centrifuge the potassium fluosilicate crystal slurry in a centrifuge to separate the product and the mother liquor. The mother liquor is sent to a mother liquor storage tank for recycling to dissolve potassium chloride. The product is washed with water and centrifuged, and then sent to a single-cylinder drying rotary kiln for drying. The dried product is screened through a single-layer vibrating screen to distinguish qualified products from unqualified products. The unqualified products are centrifuged, washed and then added to a potassium chloride dissolution tank. The qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluosilicate.

[0032] Pump the raw material fluosilicic acid with a concentration of 35% from the raw material storage tank to a fluosilicic acid blending tank, then add water to blend it into a concentration of 12%, and then send it to a filter press for pressure filtration. The silicon-containing filter residue is returned to the blending tank for recycling, and the filtrate is sent to a fluosilicic acid storage tank for standby.

[0033] Example A method for producing potassium fluosilicate includes the following steps,

[0034] Step S1: Add 15 m³ of mother liquor, 30 m³ of water and 13.5 t of potassium chloride to a potassium chloride dissolution tank and stir and mix evenly. Then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 240 g / L, send it to a filter press for pressure filtration. Then send the filtrate to a potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to a filter press for pressure filtration again. The filtrate after pressure filtration is stored in a potassium chloride storage tank for standby;

[0035] Step S2: Pump the potassium chloride solution and refined fluosilicic acid to a potassium chloride metering tank and a fluosilicic acid metering tank for metering respectively. Then simultaneously send the metered 9 m³ of potassium chloride solution and 7.5 m³ of 3 Mother liquor, 30 m³ of 3 Water and 13.5 t of potassium chloride are stirred and mixed evenly. Then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 240 g / L, send it to a filter press for pressure filtration. Then send the filtrate to a potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to a filter press for pressure filtration again. The filtrate after pressure filtration is stored in a potassium chloride storage tank for standby;

[0036] Potassium chloride solution and 7.5 m³ of 3 Potassium chloride solution and 7.5 m³ of3 The refined fluorosilicic acid is fed into the synthesis tank through pipelines simultaneously and reacts for 1 h under normal temperature and pressure. After the reaction is completed, potassium fluorosilicate crystal slurry is obtained.

[0037] Step S3: Centrifuge the potassium fluorosilicate crystal slurry in a centrifuge to separate the product and the mother liquor. The mother liquor is sent to the mother liquor storage tank for recycling to dissolve potassium chloride. The product is washed with clear water, centrifuged, and then sent to a single-cylinder drying rotary kiln for drying. The dried product is screened through a single-layer vibrating screen to distinguish qualified products from unqualified products. The unqualified products are centrifuged, washed, and then added to the potassium chloride dissolution tank. The qualified products are packaged and formed by an automatic packaging machine, and potassium fluorosilicate is obtained.

[0038] The refined fluorosilicic acid is prepared by the following steps:

[0039] The raw material fluorosilicic acid with a concentration of 40% is pumped from the raw material storage tank to the fluorosilicic acid blending tank, and then water is added to blend it into a concentration of 12%. After that, it is sent to a filter press for filtration. The silicon-containing filter residue is returned to the blending tank for recycling, and the filtrate is sent to the fluorosilicic acid storage tank for standby.

[0040] In the description of the specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0041] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar ways to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. A production method of potassium fluorosilicate, characterized in that, it comprises the following steps: Step S1: Add mother liquor, water and potassium chloride into the potassium chloride dissolution tank, stir and mix evenly, then add hydrochloric acid with a concentration of 6 mol / L to adjust the pH of the solution to 5.

3. After starting the stirrer and stirring for 1.5 h, take the potassium chloride solution for analysis and testing. After the potassium chloride concentration reaches 220 - 240 g / L, send it to a filter press for filtration. Then send the filtrate to a potassium chloride impurity removal tank for impurity removal. After impurity removal, the filtrate is sent to a filter press for filtration again. The filtrate after filtration is stored in a potassium chloride storage tank for standby; Step S2: Pump the filtrate after filtration and refined fluosilicic acid to a potassium chloride metering tank and a fluosilicic acid metering tank respectively for metering. Then send the metered filtrate after filtration and refined fluosilicic acid into a synthesis tank through a pipeline at the same time and react for 1 h under normal temperature and pressure. After the reaction is completed, a potassium fluorosilicate crystal slurry is obtained; Step S3: Centrifuge the potassium fluorosilicate crystal slurry in a centrifuge to separate the product and the mother liquor. The mother liquor is sent to a mother liquor storage tank for recycling to dissolve potassium chloride. The product is washed with clear water and centrifuged, and then sent to a single - cylinder drying rotary kiln for drying. The dried product is screened through a single - layer vibrating screen to distinguish qualified products and unqualified products. The unqualified products are centrifuged, washed and then added to the potassium chloride dissolution tank. The qualified products are packaged and formed by an automatic packaging machine, and potassium fluorosilicate is obtained; The refined fluosilicic acid is prepared by the following steps: Pump the raw fluosilicic acid with a concentration of 30 - 40% from the raw material storage tank to a fluosilicic acid blending tank, add water to blend it into a concentration of 12%, then send it to a filter press for filtration. The silicon - containing filter residue is returned to the blending tank for recycling, and the filtrate is sent to a fluosilicic acid storage tank for standby; In step S2, the dosages of the filtrate after pressure filtration and refined fluorosilicic acid are 3 - 9 m 3 : 2.5 - 7.5 m 3 ; The dosage ratio of recycled mother liquor, water and potassium chloride in the potassium chloride solution is 5 - 15m 3 : 10 - 30m 3 : 4.5 - 13.5t.

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