阅读说明：本技术 一种热镀锌酸雾吸收联产氯化钙的方法 (Method for co-producing calcium chloride by hot galvanizing acid mist absorption ) 是由 魏明 金红祥 洪剑波 张方金 张文栋 刘岩 王世强 李积升 于 2020-06-08 设计创作，主要内容包括：本发明提供了一种热镀锌酸雾吸收联产氯化钙的方法,属于资源综合利用技术领域。本发明所述方法包括以下步骤：将钙基循环碱液以喷淋的方式与热镀锌酸雾混合,进行喷淋吸收,得到氯化钙溶液；将所述氯化钙溶液依次进行蒸发浓缩、压滤和冷却结晶,得到氯化钙。本发明在对热镀锌酸雾进行吸收的同时,将所得吸收液(氯化钙溶液)制成氯化钙产品,可消除或减少热镀锌酸雾对环境的污染,同时还可联产氯化钙,工序简单、能耗低、成本低、能够实现资源综合利用。本发明的方法酸雾吸收率高(可达96.1％),而且所得氯化钙产品的纯度高(可达98.5％)。(The invention provides a method for co-producing calcium chloride by hot galvanizing acid mist absorption, belonging to the technical field of comprehensive utilization of resources. The method comprises the following steps: mixing the calcium-based circulating alkali liquor with hot galvanizing acid mist in a spraying manner, and spraying and absorbing to obtain a calcium chloride solution; and sequentially carrying out evaporation concentration, filter pressing and cooling crystallization on the calcium chloride solution to obtain calcium chloride. The method can absorb the hot galvanizing acid mist and prepare the obtained absorption liquid (calcium chloride solution) into a calcium chloride product, thereby eliminating or reducing the pollution of the hot galvanizing acid mist to the environment, simultaneously co-producing calcium chloride, having simple process, low energy consumption and low cost and realizing the comprehensive utilization of resources. The method of the invention has high acid mist absorption rate (up to 96.1 percent) and high purity of the obtained calcium chloride product (up to 98.5 percent).)

1. A method for co-producing calcium chloride by absorbing hot galvanizing acid mist comprises the following steps:

mixing the calcium-based circulating alkali liquor with hot galvanizing acid mist in a spraying manner, and spraying and absorbing to obtain a calcium chloride solution;

and sequentially carrying out evaporation concentration, filter pressing and cooling crystallization on the calcium chloride solution to obtain calcium chloride.

2. The method according to claim 1, wherein the pH value of the calcium-based circulating lye is 11 to 12.5.

3. The method as claimed in claim 1 or 2, wherein the calcium-based circulating lye is a supernatant obtained by mixing quicklime and water or a supernatant obtained by mixing carbide slag and water.

4. The method according to claim 1, wherein the content of HCl in the hot galvanizing acid mist is 10-20 mg/m³。

5. The method as claimed in claim 1, wherein the calcium-based circulating lye is circulated and sprayed in the spray tower during the spraying.

6. The method according to claim 5, characterized in that the hot galvanizing acid mist is introduced into a spray tower through a pipeline by using an induced draft fan for spray absorption.

7. The method as claimed in claim 1, wherein the calcium chloride solution is returned to the collection pool through a liquid outlet, and then is subjected to evaporative concentration, pressure filtration and cooling crystallization in sequence.

8. The method according to claim 1, wherein the mass fraction of the calcium chloride solution obtained after evaporation concentration is 45-51%.

9. The method according to claim 1, wherein the temperature of the cooling crystallization is 0 to 10 ℃.

Technical Field

The invention relates to the technical field of comprehensive utilization of resources, in particular to a method for co-producing calcium chloride by hot galvanizing acid mist absorption.

Background

With the rapid development of economy, particularly the great development of industry, the demand on hot-dip galvanized steel is more and more, and the hot-dip galvanizing industry has abnormal fire and heat. However, the air quality in the hot galvanizing workshop has a great problem, and pollutants discharged in the process flow influence the production and life of people, so that the hot galvanizing workshop has attracted extensive social attention. Wherein, the acid mist pollution of the large pickling tank is particularly serious, which directly affects the health of staff, corrodes plant equipment and pollutes the environment of a factory.

The existing acid mist absorption technology is carried out in a mode of collecting and spraying acid mist, but waste liquid after spraying and absorption is not utilized, and a lot of waste liquid is directly discharged, so that environmental pollution and resource waste are caused.

Disclosure of Invention

The invention aims to provide a method for absorbing hot galvanizing acid mist and co-producing calcium chloride.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a method for absorbing hot galvanizing acid mist and co-producing calcium chloride, which comprises the following steps:

mixing the calcium-based circulating alkali liquor with hot galvanizing acid mist in a spraying manner, and spraying and absorbing to obtain a calcium chloride solution;

and sequentially carrying out evaporation concentration, filter pressing and cooling crystallization on the calcium chloride solution to obtain calcium chloride.

Preferably, the pH value of the calcium-based circulating alkali liquor is 11-12.5.

Preferably, the calcium-based circulating alkali liquor is a supernatant obtained by mixing quicklime and water or a supernatant obtained by mixing carbide slag and water.

Preferably, the content of HCl in the hot galvanizing acid mist is 10-20 mg/m³。

Preferably, in the spraying process, the calcium-based circulating alkali liquor is circularly sprayed in the spraying tower.

Preferably, the hot galvanizing acid mist is introduced into the spray tower by a draught fan through a pipeline for spray absorption.

Preferably, the calcium chloride solution returns to the collecting tank through a liquid outlet, and then is subjected to evaporation concentration, filter pressing and cooling crystallization in sequence.

Preferably, the mass fraction of the calcium chloride solution obtained after evaporation and concentration is 45-51%.

Preferably, the temperature of the cooling crystallization is 0-10 ℃.

The invention provides a method for absorbing hot galvanizing acid mist and co-producing calcium chloride, which comprises the following steps: mixing the calcium-based circulating alkali liquor with hot galvanizing acid mist in a spraying manner, and spraying and absorbing to obtain a calcium chloride solution; and sequentially carrying out evaporation concentration, filter pressing and cooling crystallization on the calcium chloride solution to obtain calcium chloride. The method can absorb the hot galvanizing acid mist and prepare the obtained absorption liquid (calcium chloride solution) into a calcium chloride product, thereby eliminating or reducing the pollution of the hot galvanizing acid mist to the environment, simultaneously co-producing calcium chloride, having simple process, low energy consumption and low cost and realizing the comprehensive utilization of resources.

The method of the invention has high acid mist absorption rate (up to 96.1 percent) and high purity of the obtained calcium chloride product (up to 98.5 percent).

Drawings

FIG. 1 is a flow chart of the method for co-production of calcium chloride by hot galvanizing acid mist absorption according to the invention.

Detailed Description

The invention provides a method for absorbing hot galvanizing acid mist and co-producing calcium chloride, which comprises the following steps:

mixing the calcium-based circulating alkali liquor with hot galvanizing acid mist in a spraying manner, and spraying and absorbing to obtain a calcium chloride solution;

and sequentially carrying out evaporation concentration, filter pressing and cooling crystallization on the calcium chloride solution to obtain calcium chloride.

In the present invention, the required raw materials are all commercially available products well known to those skilled in the art, unless otherwise specified.

The calcium-based circulating alkali liquor is mixed with hot galvanizing acid mist in a spraying mode for spraying and absorption to obtain the calcium chloride solution. In the invention, the content of HCl in the hot galvanizing acid mist is preferably 10-20 mg/m³More preferably 12 to 18mg/m³More preferably 15 to 16mg/m³. In the invention, the pH value of the calcium-based circulating alkali liquor is preferably 11-12.5, and more preferably 11.5-12.0. In the invention, the calcium-based circulating alkali liquor is preferably a supernatant obtained by mixing quicklime and water or a supernatant obtained by mixing carbide slag and water; the concentration of the calcium-based circulating alkali liquor is not specially limited, and the pH value range is met. In the spraying process, hot galvanizing acid mist is continuously absorbed by calcium-based circulating alkali liquor, the dosage ratio of the calcium-based circulating alkali liquor to the hot galvanizing acid mist is not specially limited, and the calcium-based circulating alkali liquor with the pH value and the hot galvanizing acid mist with HCl concentration are adopted for continuous absorption. The process of mixing to obtain the supernatant is not particularly limited in the present invention, and may be performed according to a process well known in the art. The raw materials of the calcium-based circulating alkali liquor are all solid wastes, are cheap and easily available, and can be used for preparing the calcium-based circulating alkali liquorRealizing the resource utilization of solid wastes.

In the invention, the hot galvanizing acid mist preferably contains HCl; the hot galvanizing acid mist source is not specially limited, and the hot galvanizing acid mist can be directly obtained in a hot galvanizing workshop.

In the invention, during the spraying process, the calcium-based circulating alkali liquor is preferably circularly sprayed in the spraying tower. In the invention, the hot galvanizing acid mist is preferably introduced into a spray tower by a draught fan through a pipeline for spray absorption.

In the spraying absorption process, HCl in the hot galvanizing acid mist reacts with calcium hydroxide in the calcium-based circulating alkali liquor to obtain a calcium chloride solution.

After the calcium chloride solution is obtained, the calcium chloride solution is subjected to evaporation concentration, filter pressing and cooling crystallization in sequence to obtain the calcium chloride. In the invention, the calcium chloride solution generated by spray absorption preferably returns to the collecting tank through the liquid outlet, and then is subjected to evaporative concentration, filter pressing and cooling crystallization in sequence.

The spray tower, the induced draft fan and the collecting tank are not specially limited, and conventional equipment in the field is selected.

In the invention, the mass fraction of the calcium chloride solution obtained after evaporation and concentration is preferably 45-51%. The process of evaporation concentration and filter pressing is not particularly limited in the present invention, and may be performed according to a process well known in the art. And (4) obtaining a refined calcium chloride solution after the filter pressing is finished.

In the invention, the temperature of the cooling crystallization is preferably 0-10 ℃; the cooling crystallization process is not particularly limited in the present invention, and may be performed according to a process well known in the art.

FIG. 1 is a flow chart of a method for absorbing hot galvanizing acid mist and co-producing calcium chloride, and as shown in the figure, the method collects hot galvanizing acid mist from a hot galvanizing pool, then adopts calcium-based circulating alkali liquor to spray and absorb, collects the obtained calcium chloride solution in the collection pool, sequentially carries out evaporation concentration and filter pressing to obtain refined calcium chloride solution, and obtains a calcium chloride product after cooling and crystallization.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.