CN117602629B - Production method of potassium fluosilicate - Google Patents

Abstract

The present invention discloses a method for producing potassium fluorosilicate. The production process of potassium fluorosilicate in the present invention comprises the following steps: 1) refining fluorosilicic acid and placing it in a fluorosilicic acid storage tank for standby; 2) dissolving and removing impurities from potassium chloride to obtain a potassium chloride solution; 3) reacting the refined fluorosilicic acid and the potassium chloride solution in a synthesis tank to obtain potassium fluorosilicate slurry, and then centrifuging and washing in a centrifuge to obtain potassium fluorosilicate. The production method of potassium fluorosilicate in the present invention is simple, and the filtrate and filter residue generated in the production process can be reasonably utilized, thereby reducing production costs.

Description

A method for producing potassium fluorosilicate

Technical Field

The invention belongs to the technical field of potassium fluorosilicate preparation, and specifically relates to a method for producing potassium fluorosilicate.

Background Art

Potassium fluorosilicate is used as an auxiliary agent for magnesium and aluminum smelting in the metallurgical industry, used to manufacture potassium glass, optical glass, and opaque glass in the glass industry, used to manufacture insecticides in the pesticide industry, used to manufacture intermediates in the chemical industry, used as an analytical reagent in analytical chemistry, and can also be used in ceramic synthesis of mica, etc.

Patent application number CN202211275261.5 discloses a method for preparing potassium fluorosilicate from fluorine-containing liquid. In the preparation method, silicon slag is first treated, and 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

In order to solve the above technical problems, the object of the present invention is to provide a method for producing potassium fluorosilicate.

The purpose of the present invention can be achieved through the following technical solutions:

A method for producing potassium fluorosilicate comprises the following steps:

Step S1, add mother liquor, water and potassium chloride into a potassium chloride dissolving tank and stir to mix evenly, then add hydrochloric acid with a concentration of 6 mol/L to adjust the solution pH to 5.3, turn on the stirrer to stir for 1.5 hours, take the potassium chloride solution for analysis and testing, and after the potassium chloride concentration reaches 220-240 g/L, send it to a filter press for pressure filtration, and then send the filtrate to a potassium chloride impurity removal tank for impurity removal, and the filtrate after impurity removal is sent to a filter press for pressure filtration, and the filtrate after pressure filtration is stored in a potassium chloride storage tank for standby use;

Furthermore, the usage ratio of the recycled mother liquor, water and potassium chloride is 5-15m ³ :10-30m ³ :4.5-13.5t.

Step S2, pumping potassium chloride solution and refined fluorosilicic acid to potassium chloride metering tank and fluorosilicic acid metering tank for metering respectively, then sending the metered potassium chloride solution and refined fluorosilicic acid to the synthesis tank through pipeline at the same time, and reacting at room temperature and pressure for 1h, after the reaction is completed, potassium fluorosilicate slurry is obtained, and the chemical equations involved are:

H ₂ S iF ₆ +2KC l→K ₂ S iF ₆ ↓+2HCl

Furthermore, the dosage of potassium chloride solution and refined fluorosilicic acid is 3-9m ³ : 2.5-7.5m ³ .

Step S3, centrifuging the potassium fluorosilicate slurry in a centrifuge to separate the product and the mother liquor, sending the mother liquor to the mother liquor storage tank for reuse to dissolve potassium chloride, washing the product with clean water, centrifuging, and then sending it to a single-drum drying rotary kiln for drying, the dried product is sieved by a single-layer vibrating screen to distinguish qualified products from unqualified products, the unqualified products are added to the potassium chloride dissolution tank after centrifugation and washing, and the qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluorosilicate.

The refined fluorosilicic acid is prepared by the following steps:

The raw material fluorosilicic acid with a concentration of 30-40% 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%, and then sent to the filter press for filtration. The silicon-containing filter residue is returned to the blending tank for reuse, and the filtrate is sent to the fluorosilicic acid storage tank for standby use.

Beneficial effects of the present invention:

The invention discloses a method for producing potassium fluorosilicate. Firstly, fluorosilicic acid is refined and placed in a fluorosilicic acid storage tank for standby use. Then potassium chloride is dissolved and impurities are removed to obtain a potassium chloride solution. Finally, the refined fluorosilicic acid and the potassium chloride solution are reacted in a synthesis tank to obtain potassium fluorosilicate slurry, which is then centrifuged and washed in 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 in the production process, thereby reducing the production cost.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

Figure 1 is a flow chart of the potassium fluorosilicate production process.

Figure 2 is a flow chart of the fluosilicic acid refining process.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Example 1

A method for producing potassium fluorosilicate comprises the following steps:

Step S1, add ^5m3 mother liquor, ^10m3 water and 4.5t potassium chloride into a potassium chloride dissolving tank and stir and mix evenly, then add hydrochloric acid with a concentration of 6mol/L to adjust the solution pH to 5.3, turn on the stirrer and stir for 1.5h, take the potassium chloride solution for analysis and testing, after the potassium chloride concentration reaches 220g/L, send it to a filter press for pressure filtration, then send the filtrate to a potassium chloride impurity removal tank for impurity removal, and then send the filtrate after impurity removal to a filter press for pressure filtration, and the filtrate after pressure filtration is stored in a potassium chloride storage tank for standby use;

Step S2, pumping the potassium chloride solution and the refined fluorosilicic acid to the potassium chloride metering tank and the fluorosilicic acid metering tank for metering, and then sending the measured ^3m3 potassium chloride solution and ^2.5m3 refined fluorosilicic acid into the synthesis tank through the pipeline at the same time, and reacting at room temperature and pressure for 1h. After the reaction is completed, potassium fluorosilicate slurry is obtained;

Step S3, centrifuging the potassium fluorosilicate slurry in a centrifuge to separate the product and the mother liquor, sending the mother liquor to the mother liquor storage tank for reuse to dissolve potassium chloride, washing the product with clean water, centrifuging, and then sending it to a single-drum drying rotary kiln for drying, the dried product is sieved by a single-layer vibrating screen to distinguish qualified products from unqualified products, the unqualified products are added to the potassium chloride dissolution tank after centrifugation and washing, and the qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluorosilicate.

Refined fluorosilicic acid is prepared by the following steps:

The raw material fluorosilicic acid with a concentration of 30% 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%. It is then sent to a filter press for filtration, and the silicon-containing filter residue is returned to the blending tank for reuse, and the filtrate is sent to the fluorosilicic acid storage tank for standby use.

Example 2

A method for producing potassium fluorosilicate comprises the following steps:

Step S1, add ^{10m3 of} mother liquor, ^20m3 of water and 9t of potassium chloride into a potassium chloride dissolving tank and stir and mix evenly, then add hydrochloric acid with a concentration of 6mol/L to adjust the solution pH to 5.3, turn on the stirrer and stir for 1.5h, take the potassium chloride solution for analysis and testing, after the potassium chloride concentration reaches 230g/L, send it to a filter press for pressure filtration, then send the filtrate to a potassium chloride impurity removal tank for impurity removal, and then send the filtrate after impurity removal to a filter press for pressure filtration, and the filtrate after pressure filtration is stored in a potassium chloride storage tank for standby use;

Step S2, pumping the potassium chloride solution and the refined fluorosilicic acid to the potassium chloride metering tank and the fluorosilicic acid metering tank for metering, and then sending the measured ^6m3 potassium chloride solution and ^5m3 refined fluorosilicic acid into the synthesis tank through the pipeline at the same time, and reacting at room temperature and pressure for 1h. After the reaction is completed, potassium fluorosilicate slurry is obtained;

Step S3, centrifuging the potassium fluorosilicate slurry in a centrifuge to separate the product and the mother liquor, sending the mother liquor to the mother liquor storage tank for reuse to dissolve potassium chloride, washing the product with clean water, centrifuging, and then sending it to a single-drum drying rotary kiln for drying, the dried product is sieved by a single-layer vibrating screen to distinguish qualified products from unqualified products, the unqualified products are added to the potassium chloride dissolution tank after centrifugation and washing, and the qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluorosilicate.

Refined fluorosilicic acid is prepared by the following steps:

The raw material fluorosilicic acid with a concentration of 35% 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%. It is then sent to a filter press for filtration, and the silicon-containing filter residue is returned to the blending tank for reuse, and the filtrate is sent to the fluorosilicic acid storage tank for standby use.

Example 3

A method for producing potassium fluorosilicate comprises the following steps:

Step S1, add ^{15m3 of} mother liquor, ^{30m3 of} water and 13.5t of potassium chloride into a potassium chloride dissolving tank and stir and mix evenly, then add hydrochloric acid with a concentration of 6mol/L to adjust the solution pH to 5.3, turn on the stirrer and stir for 1.5h, take the potassium chloride solution for analysis and testing, after the potassium chloride concentration reaches 240g/L, send it to a filter press for pressure filtration, then send the filtrate to a potassium chloride impurity removal tank for impurity removal, and then send the filtrate after impurity removal to a filter press for pressure filtration, and the filtrate after pressure filtration is stored in a potassium chloride storage tank for standby use;

Step S2, pumping the potassium chloride solution and the refined fluorosilicic acid to the potassium chloride metering tank and the fluorosilicic acid metering tank for metering, and then sending the measured ^9m3 potassium chloride solution and ^7.5m3 refined fluorosilicic acid into the synthesis tank through the pipeline at the same time, and reacting at room temperature and pressure for 1h. After the reaction is completed, potassium fluorosilicate slurry is obtained;

Step S3, centrifuging the potassium fluorosilicate slurry in a centrifuge to separate the product and the mother liquor, sending the mother liquor to the mother liquor storage tank for reuse to dissolve potassium chloride, washing the product with clean water, centrifuging, and then sending it to a single-drum drying rotary kiln for drying, the dried product is sieved by a single-layer vibrating screen to distinguish qualified products from unqualified products, the unqualified products are added to the potassium chloride dissolution tank after centrifugation and washing, and the qualified products are packaged and formed by an automatic packaging machine to obtain potassium fluorosilicate.

Refined fluorosilicic acid is prepared by the following steps:

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%, and then sent to the filter press for filtration. The silicon-containing filter residue is returned to the blending tank for reuse, and the filtrate is sent to the fluorosilicic acid storage tank for standby use.

In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims (4)

1. The production method of the potassium fluosilicate is characterized by comprising the following steps of:

Step S1, adding mother liquor, water and potassium chloride into a potassium chloride dissolving tank, stirring and mixing uniformly, adding hydrochloric acid with the concentration of 6mol/L to adjust the pH value of the solution to 5.3, starting a stirrer to stir for 1.5 hours, taking the potassium chloride solution for analysis and test, sending the solution into a filter press to filter-press after the concentration of the potassium chloride is 220-240g/L, sending filtrate into a potassium chloride impurity removal tank to remove impurities, sending the filtrate after impurity removal into the filter press to filter-press again, and storing the filtrate after filter pressing in a potassium chloride storage tank for standby;

s2, pumping the potassium chloride solution and the refined fluosilicic acid into a potassium chloride metering tank and a fluosilicic acid metering tank respectively for metering, then simultaneously conveying the metered potassium chloride solution and the refined fluosilicic acid into a synthesis tank through a pipeline, reacting for 1h at normal temperature and normal pressure, and obtaining potassium fluosilicate crystal slurry after the reaction is completed;

And S3, centrifuging the potassium fluosilicate crystal slurry in a centrifuge to separate out products and mother liquor, feeding the mother liquor into a mother liquor storage tank for recycling and dissolving potassium chloride, washing and centrifuging the products with clear water, then feeding the products into a single-cylinder drying rotary kiln for drying, screening the dried products through a single-layer vibrating screen to separate out qualified products and unqualified products, centrifuging and washing the unqualified products, then adding the unqualified products into a potassium chloride dissolving tank, and packaging and forming the qualified products through an automatic packaging machine to obtain the potassium fluosilicate.

2. The method according to claim 1, wherein in the step S1, the potassium chloride solution and the purified fluosilicic acid are used in an amount of 3 to 9m ³：2.5-7.5m³.

3. The method for producing potassium fluosilicate according to claim 1, wherein the dosage ratio of recycled mother liquor, water and potassium chloride in the potassium chloride solution is 5-15m ³：10-30m³: 4.5-13.5t.

4. The method for producing potassium fluosilicate according to claim 1, wherein the refined fluosilicic acid is prepared by the steps of:

pumping raw material fluosilicic acid with concentration of 30-40% from a raw material storage tank to a fluosilicic acid blending tank, adding water to blend into concentration of 12%, delivering to a filter press for filter pressing, returning silicon-containing filter residues to the blending tank for recycling, and delivering filtrate to a fluosilicic acid storage tank for standby.