阅读说明：本技术 一种碳酸氢钠制备方法 (Preparation method of sodium bicarbonate ) 是由 余龙 宋明 王建平 邹小慧 刘萍 丁维佳 王晓兵 王凤英 于 2021-03-12 设计创作，主要内容包括：发明涉及一种碳酸氢钠制备方法,其步骤为：S1、配制碱液,将液碱加热至80～85℃,混合配制成碱度为80～85Ti的碱液；S2、将碱液进行过滤,得到澄清度≤0.5号浊度标准的料液,并将此液打入碳化塔中；S3、将液态二氧化碳汽化后通入步骤S2中的碳化塔中,进行碳化反应,碳化过程中要求二氧化碳压力为0.15～0.18MPa,最后生成碳酸氢钠悬浮液,即晶浆；出碱液PH值≤8,出碱温度为60～65℃；S4、然后将晶浆进行离心分离,分离出氯化物≤0.0016%、澄清度≤0.5号浊度的半成品产物,还分离出母液；S5、将步骤S4中的半成品产物进行干燥、包装、入库。本发明达到的有益效果是：各项杂质积累慢、母液膨胀速度减慢、产品持续生产周期相对较长。(The invention relates to a preparation method of sodium bicarbonate, which comprises the following steps: s1, preparing alkali liquor, heating the alkali liquor to 80-85 ℃, and mixing to prepare the alkali liquor with the alkalinity of 80-85 Ti; s2, filtering the alkali liquor to obtain a feed liquid with the clarity not more than 0.5 and with the turbidity standard, and pumping the feed liquid into a carbonization tower; s3, vaporizing the liquid carbon dioxide, introducing the vaporized liquid carbon dioxide into the carbonization tower in the step S2, and carrying out carbonization reaction, wherein the pressure of the carbon dioxide is required to be 0.15-0.18 MPa in the carbonization process, and finally generating a sodium bicarbonate suspension, namely crystal slurry; the pH value of the discharged alkali liquor is less than or equal to 8, and the temperature of the discharged alkali liquor is 60-65 ℃; s4, performing centrifugal separation on the crystal mush to separate a semi-finished product with the turbidity of no more than 0.0016% and the clarity of no more than 0.5, and also separating mother liquor; and S5, drying, packaging and warehousing the semi-finished product in the step S4. The invention achieves the following beneficial effects: slow accumulation of various impurities, slow expansion speed of mother liquor and relatively long continuous production period of products.)

1. A preparation method of sodium bicarbonate is characterized by comprising the following steps: the method comprises the following steps:

s1, preparing alkali liquor, mixing the ionic membrane industrial sodium hydroxide and purified water to form liquid alkali, heating the liquid alkali to 80-85 ℃, and mixing to prepare the alkali liquor, wherein the alkalinity of the alkali liquor is 80-85 Ti; when the mother liquor is generated after 1 day of production, the mother liquor is used for replacing purified water;

s2, filtering the prepared alkali liquor to obtain a feed liquid with the clarity not more than 0.5 turbidity standard, and pumping the filtered feed liquid into a carbonization tower;

s3, introducing the vaporized liquid carbon dioxide into a carbonization tower, and carrying out carbonization reaction on the liquid carbon dioxide and the feed liquid in the step S2 to finally generate sodium bicarbonate crystal suspension, namely crystal slurry; the pH value of the discharged alkali liquor is less than or equal to 8, and the temperature of the discharged alkali liquor is 60-65 ℃;

s4, performing centrifugal separation on the crystal mush to separate a semi-finished product with the turbidity of no more than 0.0016% and the clarity of no more than 0.5, and also separating mother liquor;

and S5, drying, packaging and warehousing the semi-finished product in the step S4.

2. A process for the preparation of sodium bicarbonate according to claim 1, characterized in that: in the step S1, the liquid caustic soda is placed in a soda dissolving tank, the mother liquor is added, the temperature is heated to 80-85 ℃, and the alkali liquor with the total alkalinity of 80-85 Ti is prepared.

3. A process for the preparation of sodium bicarbonate according to claim 2, characterized in that: and S2, filtering the feed liquid, sampling after filtering, and sending the qualified feed liquid into a carbonization tower when the turbidity standard of the feed liquid is not more than 0.5.

4. A process for the preparation of sodium bicarbonate according to claim 3, characterized in that: in the step S3, the liquid carbon dioxide is vaporized and enters from the bottom of the carbonization tower, and the tower pressure is adjusted to 0.15 to 0.18MPa, and undergoes a carbonization reaction with the feed liquid in the tower to generate a sodium bicarbonate crystal suspension.

5. The method for preparing sodium bicarbonate according to claim 4, characterized in that: in the step S3, the PH value and the temperature of the feed liquid at the bottom of the carbonization tower are adjusted, and when the temperature is 60-65 ℃ and the PH value is less than or equal to 8, the feed liquid is discharged to an alkali outlet tank through an alkali outlet at the bottom of the tower.

6. The method for preparing sodium bicarbonate according to claim 5, characterized in that: in the step S3, the carbon dioxide entering from the bottom undergoes a carbonization reaction with the feed liquid during the rising process, and the tail gas is discharged from the top of the carbonization tower after the reaction, wherein the tail gas contains carbon dioxide gas;

and the discharged tail gas is separated by a gas-liquid separator to form a gas part and a liquid part, the gas part is emptied, and the liquid part is discharged into a mother liquid tank and then transferred into a mother liquid storage tank.

7. A method for preparing sodium bicarbonate according to any one of claims 3 to 5, characterized in that: in the step S4, before starting the centrifuge, the cooling water of the hydraulic system is started, the hydraulic pump is started, and the centrifuge main machine is started; then, the feeding is started to carry out centrifugal separation, sodium bicarbonate crystals and mother liquor are separated, purified water is used for washing while the crystals are separated, the crystals after dehydration are removed from a drying system, and the filtrate enters a mother liquor pool.

8. The method for preparing sodium bicarbonate according to claim 7, characterized in that: in the step S5, hot air flow is adopted for drying, and the drying is sequentially carried out on the front section, the middle section and the tail section of the dryer, wherein the drying temperature of the front section is 120-140 ℃, and the drying temperature of the middle section is 70-90 ℃; the drying temperature of the tail section is 65-85 ℃.

Technical Field

The invention relates to the field of medicine preparation, in particular to a preparation method of sodium bicarbonate.

Background

When the sodium bicarbonate is prepared, the common raw material is sodium carbonate, but the sodium carbonate has more impurities and high impurity content, and the impurity content is accumulated quickly in the production process; when producing high-quality or higher-grade product injections, problems such as a high accumulation of impurity content in a short time and a swelling of mother liquor occur, which are very disadvantageous for the continuous and efficient production.

Therefore, the company improves the production process to solve the problem that impurities such as chloride ions are accumulated quickly so as to overcome the problem that the production cannot be continuously and effectively carried out.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a preparation method of sodium bicarbonate with relatively slow impurity accumulation and capability of continuous production.

The purpose of the invention is realized by the following technical scheme: a preparation method of sodium bicarbonate comprises the following steps:

s1, preparing alkali liquor, mixing the ionic membrane industrial sodium hydroxide and purified water to form liquid alkali, heating the liquid alkali to 80-85 ℃, and mixing to prepare the alkali liquor, wherein the alkalinity of the alkali liquor is 80-85 Ti; when the mother liquor is generated after 1 day of production, the mother liquor is used for replacing purified water;

s2, filtering the prepared alkali liquor to obtain a feed liquid with the clarity not more than 0.5 turbidity standard, and pumping the filtered feed liquid into a carbonization tower;

s3, introducing the vaporized liquid carbon dioxide into a carbonization tower, and carrying out carbonization reaction on the liquid carbon dioxide and the feed liquid in the step S2 to finally generate a sodium bicarbonate crystal suspension; in the carbonization process, the pressure of carbon dioxide entering the tower is required to be 0.15-0.18 MPa, the temperature of alkali discharged is 60-65 ℃, and the pH value of the alkali discharged liquid is less than or equal to 8;

s4, then carrying out centrifugal separation to separate a semi-finished product with the turbidity of no more than 0.0016% of chloride and no more than 0.5% of clarity, and also separating mother liquor;

and S5, drying, packaging and warehousing the semi-finished product in the step S4.

Further, in the step S1, the liquid caustic soda is placed in a soda dissolving tank, the mother liquor is added, the temperature is heated to 80-85 ℃, and the alkali liquor with the total alkalinity of 80-85 Ti is prepared.

And step S2, filtering the feed liquid, pumping the filtered feed liquid to a lye tank through a pipeline, sampling the filtered feed liquid, opening an outlet valve of a feed pump to feed the filtered feed liquid to the upper part of the carbonization tower when the turbidity standard of the feed liquid is not more than 0.5 is qualified after the filtered feed liquid is filtered.

Further, in step S3, the liquid carbon dioxide is vaporized and enters from the bottom of the carbonization tower, and the pressure at the bottom of the carbonization tower is adjusted to 0.15 to 0.18MPa, and undergoes a carbonization reaction with the liquid material in the tower to produce a sodium bicarbonate crystal suspension.

Further, in the step S3, the PH and the temperature of the feed liquid at the bottom of the carbonization tower are adjusted, and when the temperature is 60 to 65 ℃ and the PH is not more than 8, the feed liquid is discharged to the alkali outlet tank through the alkali outlet at the bottom of the carbonization tower.

Preferably, in step S3, the carbon dioxide at the bottom of the carbonization tower and the feed liquid entering from the top of the carbonization tower are subjected to a carbonization reaction during the ascending process, and a tail gas containing carbon dioxide is discharged from the top of the carbonization tower after the carbonization reaction; the discharged tail gas is separated by a gas-liquid separator to form a gas part and a liquid part, the gas part is emptied, and the liquid part is discharged into a mother liquid tank and then transferred into a mother liquid storage tank.

Further, in step S4, before starting the centrifuge, the cooling water of the hydraulic system is started, the hydraulic pump is started, and the centrifuge main unit is started; then, the feeding is started to carry out centrifugal separation, sodium bicarbonate crystals and mother liquor are separated, purified water is used for washing while the crystals are separated, the crystals after dehydration are removed from a drying system, and the filtrate enters a mother liquor pool.

Further, in the step S5, drying by hot air flow, sequentially drying by a front section, a middle section and a tail section, wherein the drying temperature of the front section is 120-140 ℃, and the drying temperature of the middle section is 70-90 ℃; the drying temperature of the tail section is 65-85 ℃.

The invention has the following advantages:

(1) the alkali liquor is prepared by adopting the industrial sodium hydroxide of the ionic membrane, and a high-quality sodium bicarbonate product can be produced.

A. Filtering the prepared alkali liquor to obtain a feed liquid with the clarity of no more than 0.5, and carrying out carbonization reaction on the feed liquid and carbon dioxide to obtain a sodium bicarbonate crystal suspension;

B. the prepared alkali liquor has the advantages that as various impurities of the raw material of the sodium hydroxide in the ionic membrane industry are lower than those of the traditional sodium carbonate raw material, especially the content of chloride ions is very low, the impurities are slowly accumulated and the mother liquor is slowly expanded when the sodium hydroxide is filtered and then participates in the carbonization reaction, frequent shutdown and cleaning are not needed, so that continuous production can be realized, and the quality of the generated sodium bicarbonate is very stable;

(2) when centrifugal separation is adopted, purified water is introduced into the centrifugal machine to be mixed with the feed for dehydration, so that the washing effect is achieved, and high-quality sodium bicarbonate is separated.

Detailed Description

The present invention is further described below, but the scope of the present invention is not limited to the following.

Example 1

A preparation method of sodium bicarbonate comprises the following steps:

s1, preparing an alkali liquor, mixing the ionic membrane industrial sodium hydroxide and purified water to obtain a liquid alkali, placing the liquid alkali in an alkali dissolving tank, heating to 80-85 ℃, and preparing the alkali liquor with the total alkalinity of 80 Ti; when the mother liquor is generated after 1 day of production, the mother liquor is used for replacing purified water;

s2, filtering the prepared alkali liquor;

filtering the alkali liquor through a filter: opening an outlet valve of the filter, starting a pipeline pump of the alkali dissolving tank, passing through the filter to the alkali dissolving tank, sampling during filtration, and qualified when the turbidity standard of the clarity degree is less than or equal to 0.5; opening an outlet valve of the filter, and feeding qualified feed liquid from the upper part of the carbonization tower;

s3, after being vaporized, liquid carbon dioxide enters from the bottom of the carbonization tower and is subjected to carbonization reaction with the feed liquid in the tower to generate sodium bicarbonate crystallization suspension;

adjusting the pressure at the bottom of the tower to be 0.15-0.18 MPa through a tail gas outlet valve of the carbonization tower, adjusting the temperature of an alkali outlet at the bottom of the carbonization tower, and adjusting the pH value of a feed liquid; when the temperature of the bottom alkali outlet is 60-65 ℃ and the pH value of the feed liquid is less than or equal to 8, putting the feed liquid in the carbonization tower into an alkali outlet groove from the bottom of the carbonization tower;

partial carbon dioxide in the carbonization tower does not participate in the reaction, the partial carbon dioxide is discharged from the top of the carbonization tower, tail gas is separated by a gas-liquid separator to form a gas part and a liquid part, the gas part is emptied, and the liquid part is discharged into a mother liquid tank and then transferred into a mother liquid storage tank;

s4, centrifuging the sodium bicarbonate crystal suspension in the step S3;

before starting the centrifugal machine, firstly starting cooling water of a hydraulic system, and then starting a hydraulic pump;

after the hydraulic pump normally rotates, namely when the pump current is less than 3.7A and the pump pressure is less than or equal to 4MPa in the embodiment, the host machine of the centrifuge is started;

when the centrifuge operates normally, that is, after the current in this embodiment is reversed to be close to 0, the centrifuge is restarted to reach 40A again, and the separation and dehydration of the feed are started; in the process of separating and dehydrating the centrifuge, the current of a main machine of the centrifuge is controlled to be within 100A;

the dehydration was performed while adding purified water for washing; after centrifugal separation and dehydration, the separated filtrate directly enters a mother liquor pool, wherein the semi-finished product has the turbidity of less than or equal to 0.0016% of chloride and less than or equal to 0.5 of clarity;

and S5, drying, packaging and warehousing the semi-finished product in the step S4.

And (3) drying: starting an air blower and an induced draft fan of a drying system, opening a steam valve of a heat exchanger, controlling the temperature of the front section of the dryer to reach 120.0-140.0 ℃, controlling the temperature by using the feeding speed, controlling the temperature of the middle section to be 70-90 ℃ and the temperature of the tail section to be 65-85 ℃, and controlling the water content of an intermediate product, namely sodium bicarbonate, to be less than or equal to 0.2 percent after drying;

packaging and warehousing: the intermediate product sodium bicarbonate at the tail part of the dryer enters a storage bin after being separated by a cyclone separator; the sodium bicarbonate entering the storage bin is separated by the cyclone separator and is directly subpackaged and packaged from the storage bin.

Example 2

A process for the preparation of sodium bicarbonate, similar to the examples, with the difference that: and in the step S1, preparing the alkalinity of the alkali liquor to be 82 Ti.

Example 3

A process for the preparation of sodium bicarbonate, similar to the examples, with the difference that: the alkalinity of the prepared alkali liquor in the step S1 is 85 Ti.

In addition, the charging amounts of the three examples of the ionic membrane industrial sodium hydroxide and the liquid carbon dioxide are shown in table 1, and the purified water is used for adjustment.

TABLE 1 solid ton of sodium hydroxide from the Ionic Membrane industry

However, liquid sodium hydroxide from the ionic membrane industry can also be used, and the feed amounts are shown in Table 2.

TABLE 2 Industrial sodium hydroxide liquid feed amount per ton product by using ionic membrane

The above examples only represent preferred embodiments, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.