阅读说明：本技术 一种精制液体硅酸钠的生产方法 (Production method of refined liquid sodium silicate ) 是由 王敬伟 纪发达 聂梓新 于 2019-10-17 设计创作，主要内容包括：本发明涉及精制液体硅酸钠的生产方法。该方法包括如下步骤：(1)在反应釜内装入石英砂与烧碱溶液搅拌后,向反应釜内充入水蒸汽,待反应釜内温度达到110-130℃时,停止向反应釜内充入水蒸汽；(2)反应釜内压力保持在0.6-0.8Mpa,进行液相反应；(3)反应3-4小时后,进行泄压；(4)当反应釜内压力降至0.2-0.4Mpa时,停止泄压,开启放料阀门；(5)将液体硅酸钠粗液通过过滤得到精制液体硅酸钠。本发明的方法能够解决现有液体硅酸钠生产工艺中存在的浪费能源、处理时间长、生产效率低、投资费用高等问题,并且本发明的工艺方法操作简单,能够制备高纯度的液体硅酸钠。(The present invention relates to a production method of refined liquid sodium silicate. The method comprises the following steps: (1) filling quartz sand and caustic soda solution into a reaction kettle, stirring, filling water vapor into the reaction kettle, and stopping filling the water vapor into the reaction kettle when the temperature in the reaction kettle reaches 110-; (2) the pressure in the reaction kettle is kept between 0.6 and 0.8Mpa, and liquid phase reaction is carried out; (3) after reacting for 3-4 hours, carrying out pressure relief; (4) when the pressure in the reaction kettle is reduced to 0.2-0.4Mpa, stopping pressure relief, and opening a discharge valve; (5) and filtering the liquid sodium silicate crude liquid to obtain refined liquid sodium silicate. The method can solve the problems of energy waste, long treatment time, low production efficiency, high investment cost and the like in the conventional liquid sodium silicate production process, and the process method is simple to operate and can be used for preparing high-purity liquid sodium silicate.)

1. A method for producing refined liquid sodium silicate, said method comprising the steps of:

(1) filling quartz sand and caustic soda solution into a reaction kettle, stirring, filling water vapor into the reaction kettle, and stopping filling the water vapor into the reaction kettle when the temperature in the reaction kettle reaches 110-;

(2) the pressure in the reaction kettle is kept between 0.6 and 0.8Mpa, and liquid phase reaction is carried out;

(3) carrying out pressure relief after reaction;

(4) when the pressure in the reaction kettle is reduced to 0.2-0.4Mpa, stopping pressure relief, and opening a discharge valve;

(5) and filtering the liquid sodium silicate crude liquid to obtain refined liquid sodium silicate.

2. The production method according to claim 1, wherein the silica content in the silica sand is 99% or more.

3. The production method according to claim 1 or 2, wherein the sodium hydroxide solution has a sodium hydroxide concentration of 45 to 55 wt%.

4. The production method according to any one of claims 1 to 3, wherein the sodium hydroxide solution has a sodium hydroxide mass concentration of 50 wt%.

5. The production method according to any one of claims 1 to 4, wherein the mass ratio of the quartz sand to the caustic soda solution is 1:1.3 to 1.8.

6. The production process according to any one of claims 1 to 5, wherein the stirring in the reaction tank is carried out by an ultrasonic vibrator having a vibration frequency of 20 to 40 KHz.

7. The production method according to any one of claims 1 to 6, wherein the temperature in step (1) is 120 ℃.

8. The preparation method according to any one of claims 1 to 7, wherein the pressure is released after 3 to 4 hours of reaction in the step (3), and the Baume degree of the crude liquid of the liquid sodium silicate in the reaction kettle is more than or equal to 58 degrees Be'.

9. The preparation method according to any one of claims 1 to 8, wherein after the step (4), the materials in the reaction kettle firstly pass through a vapor-liquid separation tank under the pressure, water vapor is recycled, and the liquid sodium silicate crude liquid naturally flows into an intermediate tank.

10. The production method according to any one of claims 1 to 9, wherein the step of filtering in step (5) is: and (3) starting a filter pump, injecting the liquid sodium silicate crude liquid in the intermediate tank into the filter, continuously forming filter cakes on the surface of the filter screen, precoating for 1-3 hours until the liquid in the filter is clear and transparent, and finishing the filtration when the pressure of the filter is displayed above 0.3Mpa or all the filtrate is completely filtered.

11. The method according to claim 10, wherein the coating layer of the silica sand with impurities in the filter is removed and washed to be put into use again as a raw material of the silica sand.

12. The production process according to any one of claims 1 to 11, wherein in the step (5), the liquid sodium silicate obtained after filtration is subjected to secondary filtration with a filter having a mesh size of 30 μm or less.

Technical Field

The invention relates to a preparation method of sodium silicate, in particular to a production method of refined liquid sodium silicate.

Background

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a novel method for preparing refined liquid sodium silicate, which can solve the problems of energy waste, long treatment time, low production efficiency, high investment cost and the like in the existing production process of liquid sodium silicate. The process method has the advantages of simple operation, low production cost and low energy consumption, and can effectively recover the material slag and the waste water, thereby avoiding the environmental pollution.

A method for producing refined liquid sodium silicate, said method comprising the steps of:

(1) filling quartz sand and caustic soda solution into a reaction kettle, stirring, filling water vapor into the reaction kettle, and stopping filling the water vapor into the reaction kettle when the temperature in the reaction kettle reaches 110-;

(2) the pressure in the reaction kettle is kept between 0.6 and 0.8Mpa, and liquid phase reaction is carried out;

(3) carrying out pressure relief after reaction;

(4) when the pressure in the reaction kettle is reduced to 0.2-0.4Mpa, stopping pressure relief, and opening a discharge valve;

(5) and filtering the liquid sodium silicate crude liquid to obtain refined liquid sodium silicate.

Preferably, the preparation method is one in which the silica content of the silica sand is 99% or more.

Preferably, the above preparation method, wherein the sodium hydroxide mass concentration of the caustic soda solution is 45 to 55 wt%.

Preferably, the preparation method is one in which the sodium hydroxide solution has a sodium hydroxide concentration of 50 wt%.

Preferably, the preparation method is characterized in that the mass ratio of the quartz sand to the caustic soda solution is 1: 1.3-1.8.

Preferably, according to the above preparation method, wherein the stirring in the reaction vessel is carried out by an ultrasonic vibrator with a vibration frequency of 20 to 40 KHz.

Preferably, the preparation method according to the above, wherein the temperature in the step (1) is 120 ℃.

Preferably, according to the preparation method, after the reaction in the step (3) is carried out for 3-4 hours, the Baume degree of the liquid crude sodium silicate solution in the reaction kettle is more than or equal to 58 DEG Be'.

Preferably, according to the preparation method, after the step (4), the materials in the reaction kettle firstly pass through a vapor-liquid separation tank under the pressure, the water vapor is recycled, and the liquid sodium silicate crude liquid naturally flows into an intermediate tank.

Preferably, the preparation method according to the above, wherein the step of filtering in the step (5) is: and (3) starting a filter pump, injecting the liquid sodium silicate crude liquid in the intermediate tank into the filter, continuously forming filter cakes on the surface of the filter screen, precoating for 1-3 hours until the liquid in the filter is clear and transparent, and finishing the filtration when the pressure of the filter is displayed above 0.3Mpa or all the filtrate is completely filtered.

Preferably, the preparation method comprises the steps of removing the quartz sand coating with impurities in the filter, and putting the quartz sand coating into use again after washing.

Preferably, according to the preparation method, in the step (5), the liquid sodium silicate obtained after filtration is filtered for the second time by a filter with the filter mesh diameter less than or equal to 30 um.

The method can solve the problems of energy waste, long treatment time, low production efficiency, high investment cost and the like in the existing production process of the liquid sodium silicate, is simple to operate, can prepare high-purity liquid sodium silicate, and can prepare refined sodium silicate liquid with high transparency, high purity, low impurity content and stable modulus through secondary filtration of 75 micrometers and 20 micrometers. The light transmittance of the product is more than or equal to 98 percent, and the water-insoluble substance is less than 0.05 percent. The light transmittance is detected by a spectrophotometer, and the water-insoluble substances are detected by a vacuum filtration membrane method. The light transmittance of the product is 98.0-99.8%, and the water insoluble substance is 0.02-0.03%; the light transmittance of the product in the same industry is 75.0-85.0%, and the water insoluble substance is 0.07-0.20%.

Drawings

FIG. 1 is a schematic flow diagram of the preparation process of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, quartz sand and caustic soda solution are first metered by an automatic metering instrument and then conveyed into a reaction kettle, wherein the quartz sand preferably adopts quartz sand with the purity of more than 99 wt% of silicon dioxide, and the sodium hydroxide mass concentration of the caustic soda solution is preferably 45-55 wt%, and more preferably 50 wt%; the object of the present invention is to prepare sodium silicate with a low modulus, for which the mass ratio of quartz sand to caustic soda solution is set to 1: 1.3-1.8.

The material is added into the reaction kettle, and meanwhile, the stirring device of the reaction kettle is started to stir the material, and the ultrasonic vibration rod is preferably used by the stirring device.

And opening the pneumatic valve, filling water vapor into the reaction kettle, closing the pneumatic valve when the temperature in the reaction kettle reaches 120 ℃, stopping filling the water vapor into the reaction kettle, and keeping the pressure in the reaction kettle at 0.6-0.8Mpa for liquid phase reaction.

Reacting for 3-4 hours, detecting the liquid crude sodium silicate solution in the reaction kettle, opening a pressure relief valve to relieve pressure after the Baume degree is more than or equal to 58 degrees Be' through thermal measurement; when the pressure in the kettle is reduced to 0.2-0.4Mpa, the pressure relief valve is closed, and the discharge valve is opened. The materials in the kettle are pressed into the vapor-liquid separation tank under the action of pressure, the water vapor is recycled, and the liquid sodium silicate crude liquid naturally flows into the intermediate tank from the vapor-liquid separation tank.

Starting a filter pump, and injecting the liquid sodium silicate crude liquid in the intermediate tank into the filter; and (3) pre-coating is started, a filter cake is continuously formed on the surface of the filter screen along with the pre-coating, and the clear liquid in the clear liquid backflow pipeline becomes clear and transparent after about 1-3 hours of pre-coating.

When the pressure of the filter is over 0.3Mpa or the filtrate is completely filtered, the filtering is finished, the quartz sand coating with impurities in the filter is removed, and the quartz sand coating can be used as a raw material again after being washed.

And (3) filtering the filtered liquid sodium silicate for the second time by a filter (the aperture of a filter screen is less than or equal to 30 mu m) to obtain the refined liquid sodium silicate.

In the preparation method, when steam is discharged for pressure relief and the reaction kettle discharges materials, the materials pass through the steam-liquid separation tank, so that the phenomenon that the waste steam is discharged outside and drips of liquid sodium silicate are effectively prevented; the residual material slag after the reaction passes through a solid-liquid separation device, and the effective components in the waste water and the silicon slag can be recycled.

The invention is illustrated below with specific examples.

The following examples were carried out for the performance measurement of the prepared liquid sodium silicate using the following instruments and equipment:

baume degree: adopting a baume densimeter;

modulus: measuring the content of sodium oxide and silicon oxide according to the national standard of GB/T4209-2008 industrial sodium silicate, and calculating the content of silicon dioxide (SiO)₂) And sodium oxide (Na)₂O) is the modulus.

Light transmittance: adopting a spectrophotometer of 7230G of Haichinaceae, 20G is diluted to 100ml, and then the spectrophotometer is adjusted to a light transmittance determination item for determination.

Content of water-insoluble matter: measured according to the national standard of GB/T4209-2008 industrial sodium silicate.