CN215798976U

CN215798976U - Device for preparing magnesium sulfate from flue gas desulfurization liquid by magnesium oxide method

Info

Publication number: CN215798976U
Application number: CN202121392594.7U
Authority: CN
Inventors: 王佐任; 冯彬; 陈家光; 高伟
Original assignee: Weifang Lianxing New Material Technology Co ltd
Current assignee: Weifang Lianxing New Material Technology Co ltd
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2022-02-11
Anticipated expiration: 2031-06-22

Abstract

The utility model discloses a device for preparing magnesium sulfate from magnesium oxide flue gas desulfurization liquid, which comprises a desulfurization tower, wherein the bottom of the desulfurization tower is provided with a pipeline and a pump which are communicated with a desulfurization circulating water tank; the upper part of the desulfurization circulating water tank is provided with a magnesium oxide bin, and the desulfurization circulating water tank is sequentially communicated with a sedimentation tank, a water jacket circulating water tank, an airing tank and a crystallizing tank through a pipeline and a pump. The utility model overcomes the defects in the prior art, and has the advantages of simple and efficient treatment mode, safe and reliable treatment process, energy saving and environmental protection.

Description

Device for preparing magnesium sulfate from flue gas desulfurization liquid by magnesium oxide method

Technical Field

The utility model belongs to the technical field of chemical production, and particularly relates to a device for preparing magnesium sulfate from flue gas desulfurization liquid by a magnesium oxide method.

Background

At present, along with the development of the aluminum industry, the increment of a petroleum coke calcining furnace is driven, a new problem of high-temperature flue gas desulfurization after calcining is increased, most professional desulfurization companies aim at flue gas desulfurization of the calcining furnace, and the desulfurization process is continuously developed. The chemical reaction activity of the magnesium oxide as a desulfurizer is far higher than that of a calcium-based desulfurizer. The currently proven magnesium oxide reserves in China are about 160 hundred million tons, which accounts for about 80% of the world, and the development of a mature magnesium oxide desulphurization process has important significance.

However, through the follow-up investigation of the magnesium oxide desulphurization project in recent years, the following problems are found to exist in the traditional calcium oxide slurry washing-regeneration desulphurization process after long-term operation: 1. the process is complex and the investment is large; 2. the regeneration rate of the magnesium oxide is low. The magnesium sulfite calcination regeneration magnesium oxide needs a temperature above 800 ℃, the magnesium sulfate calcination regeneration magnesium oxide needs a higher temperature, and the magnesium oxide conversion rate is lower and lower along with the increase of the magnesium sulfate content in the system; 3. the actual running cost is high. Poor control of the regeneration process results in greater heat loss and also consumes a large amount of reduced carbon; 4. fouling in the column. Because the regeneration rate of the magnesium oxide is low, the desulfurization efficiency is reduced, and in order to maintain higher desulfurization efficiency, the pH value needs to be controlled to be more than 7, so that a large amount of desulfurization circulating liquid cannot be treated, and the production cost is high.

The problems seriously affect the application of the magnesium oxide method in the domestic flue gas desulfurization of small and medium-sized units.

Disclosure of Invention

The technical problem to be solved by the utility model is as follows: the device for preparing the magnesium sulfate from the flue gas desulfurization liquid by the magnesium oxide method overcomes the defects in the prior art, and is simple and efficient in treatment mode, safe and reliable in treatment process, energy-saving and environment-friendly.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

a device for preparing magnesium sulfate from magnesium oxide flue gas desulfurization liquid comprises a desulfurization tower, wherein a pipeline and a pump are arranged at the bottom of the desulfurization tower and communicated with a desulfurization circulating water tank; the upper part of the desulfurization circulating water tank is provided with a magnesium oxide bin, and the desulfurization circulating water tank is sequentially communicated with a sedimentation tank, a water jacket circulating water tank, an airing tank and a crystallizing tank through a pipeline and a pump.

Preferably, the sedimentation tank is provided with a plurality of sedimentation tanks.

Furthermore, the number of the sedimentation tanks is two, namely a first-stage sedimentation tank and a second-stage sedimentation tank. Magnesium sulfate liquid in the desulfurization circulating water pond is precipitated through the primary sedimentation tank and then enters the secondary sedimentation tank to be precipitated, the precipitation effect of the magnesium sulfate liquid is guaranteed, impurities which are not fully utilized in the magnesium sulfate liquid are precipitated, the impurities can be sold to a refractory material factory to be used as refractory materials, and enterprise benefits are increased.

Preferably, the water jacket circulating water tank comprises a solution temporary storage tank and a heat exchange water jacket, and the heat exchange water jacket is arranged in the solution temporary storage tank or at the upper part of the solution temporary storage tank. The heat exchange water jacket is set to be an independent operation system, the heat exchange water jacket can cool other materials in the production process, meanwhile, the magnesium sulfate liquid conveyed by the secondary sedimentation tank is heated and evaporated (pumped into the heat exchange water jacket from the solution temporary storage tank for heat exchange and then returned to the solution temporary storage tank), the baume degree of the magnesium sulfate solution is improved, and when the magnesium sulfate solution in the solution temporary storage tank reaches a certain baume degree, the magnesium sulfate solution is conveyed to the airing tank for airing.

Preferably, the drying pool is provided with a plurality of drying pools. And enough space is ensured for airing the magnesium sulfate solution.

Preferably, a filtering device is arranged between the airing pool and the crystallizing pool. And filtering and purifying the concentrated solution with the Baume degree of about 20% obtained in the drying tank, and then conveying the concentrated solution to a crystallization tank for crystallization.

Further, the filtering device is a centrifuge.

Preferably, the crystallization tank is also communicated with a magnesium sulfate post-treatment device. Purifying the crystallized magnesium sulfate, packaging and preserving.

Due to the adoption of the technical scheme, the utility model has the beneficial effects that:

1. the utility model adopts reaction tanks of cyclic oxidation, precipitation, evaporation, crystallization and the like, and utilizes the simplest concentration and crystallization technology, thereby saving the investment cost;

2. the utility model can also independently select how to treat the wastewater and recycle the clarified liquid, thereby achieving the purpose of environmental protection.

In a word, the utility model overcomes the defects that the traditional magnesium oxide desulfurization process can not treat high-salinity wastewater, has high energy consumption, high operation cost and the like, is particularly suitable for the process for recovering magnesium sulfate by desulfurizing flue gas of small and medium-sized units in the domestic carbon industry, has simple and efficient treatment mode, safe and reliable treatment process, energy conservation and environmental protection, and plays a positive role in comprehensive utilization of energy and environmental protection in China.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

in the figure, 1, a desulfurizing tower; 2. a desulfurization circulating water tank; 3. a magnesium oxide bin; 4. a first-stage sedimentation tank; 5. a secondary sedimentation tank; 6. a water jacket circulating water tank; 7. an airing pool; 8. a crystallization tank; 9. a filtration device; 10. and a heat exchange water jacket.

Detailed Description

The utility model is further illustrated below with reference to the figures and examples.

The first embodiment is as follows:

as shown in fig. 1, the device for preparing magnesium sulfate from flue gas desulfurization liquid by a magnesium oxide method comprises a desulfurization tower 1, wherein a pipeline (not shown) and a pump (not shown) are arranged at the bottom of the desulfurization tower 1 and communicated with a desulfurization circulating water tank 2, and the desulfurization circulating water tank 2 is provided with a pipeline and a pump and communicated with the top of the desulfurization tower 1; the upper part of the desulfurization circulating water tank 2 is provided with a magnesium oxide bin 3, and the desulfurization circulating water tank 2 is also sequentially communicated with a sedimentation tank (the sedimentation tank is a primary sedimentation tank 4 and a secondary sedimentation tank 5), a water jacket circulating water tank 6, an airing tank 7 and a crystallization tank 8 through a pipeline and a pump; a filtering device 9 is arranged between the airing pool 7 and the crystallizing pool 8, and a heat exchange water jacket 10 is arranged in the water jacket circulating water pool 6.

The application principle is as follows:

in the practical operation of the utility model, firstly, the magnesium oxide in the magnesium oxide bin 3 is added into the desulfurization circulating water tank 2, the magnesium oxide in the desulfurization circulating water tank 2 is conveyed into the desulfurization tower 1 through a circulating pump for desulfurization, magnesium sulfate is formed at the same time, when the magnesium sulfate solution in the desulfurization circulating water tank 2 is saturated, the saturated solution is conveyed into the primary sedimentation tank 4 and the secondary sedimentation tank 5 for sedimentation, and simultaneously, a new round of desulfurization is carried out by injecting a new aqueous solution and the magnesium oxide into the desulfurization circulating water tank 2; and (2) conveying the supernatant in the primary sedimentation tank 4 into a secondary sedimentation tank 5, conveying the supernatant in the secondary sedimentation tank 5 into a water jacket circulating water tank 6 (containing a heat exchange water jacket 10), conveying the clear liquid subjected to heat exchange in the water jacket circulating water tank 6 into an airing tank 7 for airing until the Baume degree of the liquid is about 20%, filtering, purifying and conveying the clear liquid into a crystallizing tank 8 for crystallizing until crystals appear, and collecting and purifying the magnesium sulfate crystals to obtain the finished magnesium sulfate.

It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Claims

1. The device for preparing the magnesium sulfate from the flue gas desulfurization solution by the magnesium oxide method is characterized in that: the device comprises a desulfurizing tower, wherein a pipeline and a pump are arranged at the bottom of the desulfurizing tower and communicated with a desulfurizing circulating water tank, and the desulfurizing circulating water tank is provided with a pipeline and a pump and communicated with the top of the desulfurizing tower; the upper part of the desulfurization circulating water tank is provided with a magnesium oxide bin, and the desulfurization circulating water tank is sequentially communicated with a sedimentation tank, a water jacket circulating water tank, an airing tank and a crystallizing tank through a pipeline and a pump.

2. The device for preparing magnesium sulfate by using the flue gas desulfurization solution of the magnesium oxide method according to claim 1, which is characterized in that: the sedimentation tank is provided with a plurality of.

3. The device for preparing magnesium sulfate by using the flue gas desulfurization solution obtained by the magnesium oxide method according to claim 2, is characterized in that: the sedimentation tank is provided with two, be one-level sedimentation tank and second grade sedimentation tank respectively.

4. The device for preparing magnesium sulfate by using the flue gas desulfurization solution of the magnesium oxide method according to claim 1, which is characterized in that: the water jacket circulating water tank comprises a solution temporary storage tank and a heat exchange water jacket, and the heat exchange water jacket is arranged in the solution temporary storage tank or on the upper part of the solution temporary storage tank.

5. The device for preparing magnesium sulfate by using the flue gas desulfurization solution of the magnesium oxide method according to claim 1, which is characterized in that: the sunning pond is provided with a plurality of.

6. The device for preparing magnesium sulfate by using the flue gas desulfurization solution of the magnesium oxide method according to claim 1, which is characterized in that: and a filtering device is arranged between the airing pool and the crystallizing pool.

7. The device for preparing magnesium sulfate by using the flue gas desulfurization solution obtained by the magnesium oxide method according to claim 6, is characterized in that: the filtering device is a centrifuge.

8. The device for preparing magnesium sulfate by using the flue gas desulfurization solution of the magnesium oxide method according to claim 1, which is characterized in that: the crystallizing pond is also communicated with a magnesium sulfate post-treatment device.