CN211998955U

CN211998955U - Ammonium sulfate evaporation mother liquor heavy metal purification device

Info

Publication number: CN211998955U
Application number: CN202020129066.1U
Authority: CN
Inventors: 黄妍; 陈彪; 张俊丰; 曹靖
Original assignee: Xiangtan University
Current assignee: Xiangtan University
Priority date: 2020-01-20
Filing date: 2020-01-20
Publication date: 2020-11-24
Anticipated expiration: 2030-01-20

Abstract

The utility model discloses an ammonium sulfate evaporation mother liquor heavy metal purification device, the main body of the device is a fixed bed electrolytic tank, and the device is characterized by comprising a mother liquor inlet, a mother liquor outlet, a rectification power supply, a stainless steel electrode, a graphite electrode, a sponge carbon filler and quartz sand, wherein the mother liquor inlet is arranged at the lower part of the electrolytic tank and is connected with an outlet of a mother liquor circulating pipeline in an ammonium sulfate evaporator; the mother liquor outlet is arranged at the upper part of the electrolytic bath and is connected with the inlet of a mother liquor circulating pipeline in the ammonium sulfate evaporator, stainless steel electrodes and graphite electrodes are arranged at intervals in the electrolytic bath, and a mixture of sponge carbon and quartz sand is filled between the stainless steel electrodes and the graphite electrodes. The utility model discloses compare in traditional electrolytic device, its effective electrode area is big, and the local potential difference is controlled well, and is good, efficient to heavy metal impurity's selectivity of getting rid of.

Description

Ammonium sulfate evaporation mother liquor heavy metal purification device

Technical Field

The utility model relates to an ammonium sulfate evaporation mother liquor heavy metal purification device belongs to waste water treatment technical field.

Background

With the progress of the desulfurization technology, the ammonia wet desulfurization process is greatly developed in the fields of flue gas desulfurization, waste lead-acid battery lead plaster pre-desulfurization and the like, and the desulfurization byproduct ammonium sulfate has considerable economic value. The ammonium sulfate solution as the byproduct is evaporated and crystallized to obtain solid ammonium sulfate. However, the ammonium sulfate solution usually contains a plurality of heavy metal ions, and the concentration of the heavy metal ions is further increased along with the cyclic operation of the process, so that the quality of the ammonium sulfate product is deteriorated, and the use requirement is difficult to achieve. Therefore, it is necessary to purify the ammonium sulfate solution to remove the heavy metal impurities.

At present, the method for removing heavy metal impurities in the ammonium sulfate solution is usually flocculation sedimentation, ion exchange, membrane separation and the like, and the purified ammonium sulfate solution is evaporated, concentrated and crystallized. Although the heavy metal content can be lower than 10 mg/L, the investment of the purification device is large, and trace heavy metal ions can be accumulated in the evaporation mother liquor along with the increase of the evaporation concentration factor. Particularly, lead ions have high toxicity, and can form lead sulfate precipitates with high-concentration sulfate ions at a lower concentration and be mixed into ammonium sulfate crystals, so that evaporation mother liquor needs to be frequently discharged and treated, otherwise the quality of the ammonium sulfate product is reduced. At the same time, this greatly affects production efficiency and increases operating costs.

The electrochemical deposition method is one of effective methods for treating heavy metal in the ammonium sulfate evaporation mother liquor, heavy metal ions in the electrolyte are reduced and precipitated on the surface of a cathode by selectively adjusting electrodeposition parameters, and the removal rate of the heavy metal is high. However, the traditional electrolytic unit cell body has the defects of small treatment capacity, low current efficiency and the like. The need of industry development is to find a simple, feasible and efficient ammonium sulfate evaporation mother liquor heavy metal purification device.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an ammonium sulfate evaporation mother liquor heavy metal purifier to solve prior art inefficiency, ammonium sulfate product quality is unstable, and evaporation mother liquor must frequently discharge the problem of handling.

The technical scheme of the utility model is that:

a purification device for heavy metal in mother liquor evaporated by ammonium sulfate is characterized by comprising a mother liquor inlet, a mother liquor outlet, a rectification power supply, a stainless steel electrode, a graphite electrode, sponge carbon filler and quartz sand, wherein the mother liquor inlet is arranged at the lower part of the electrolytic tank and is connected with an outlet of a mother liquor circulating pipeline in an ammonium sulfate evaporator; the mother liquor outlet is arranged at the upper part of the electrolytic bath and is connected with the inlet of a mother liquor circulating pipeline in the ammonium sulfate evaporator, stainless steel electrodes and graphite electrodes are arranged at intervals in the electrolytic bath, and a mixture of sponge carbon and quartz sand is filled between the stainless steel electrodes and the graphite electrodes. Furthermore, the negative electrode of the rectification power supply is connected with a stainless steel electrode, and the positive electrode of the rectification power supply is connected with a graphite electrode.

Furthermore, the stainless steel electrode is made of 316L stainless steel.

Furthermore, in the mixture of the sponge carbon and the quartz sand, the mass ratio of the quartz sand is 20-30%, and the particle size of the quartz sand is 3-5 mm.

The utility model discloses following beneficial effect has:

(1) the particle spacing between the sponge carbon and the quartz sand filler is small, the mass transfer speed of the substance is increased, the effective electrode area is large, the local potential difference is well controlled, the current efficiency is improved, the energy consumption is low, and the removal selectivity of heavy metal impurities is good and the efficiency is high.

(2) The method does not need to add an oxidation reducing agent, does not produce secondary pollution, does not need to regenerate and treat the particle electrode, is easy to control and is convenient for realizing industrialization.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

As shown in fig. 1, the device of the utility model comprises a mother liquor inlet 1, a mother liquor outlet 2, a rectification power supply 3, a stainless steel electrode 4, a graphite electrode 5, sponge carbon 6 and quartz sand 7; the device main body is a fixed bed electrolytic tank; the mother liquor inlet 1 is arranged at the lower part of the electrolytic bath and is connected with an outlet of a mother liquor circulating pipeline in an ammonium sulfate evaporator; the mother liquor outlet 2 is arranged at the upper part of the electrolytic bath and is connected with an inlet of a mother liquor circulating pipeline in the ammonium sulfate evaporator. Stainless steel electrodes 4 and graphite electrodes 5 are arranged in the electrolytic cell at intervals, the positive electrode of the rectification power supply 3 is connected with the stainless steel electrodes 4, and the negative electrode of the rectification power supply is connected with the graphite electrodes 5. The stainless steel electrode 4 is made of 316L stainless steel, and a mixture of sponge carbon 6 and quartz sand 7 is filled between the stainless steel electrode 4 and the graphite electrode 5, wherein the mass ratio of the quartz sand 7 is 20-30%, and the particle size of the quartz sand 7 is 3-5 mm.

In order to examine the treatment effect of the device of the present invention, the following description is made in conjunction with the case of a specific process.

The case is implemented by aiming at the evaporation mother liquor of the ammonium sulfate which is the byproduct of the ammonium pre-desulfurization of the waste lead plaster by the ammonium method, the temperature of the evaporation mother liquor of the ammonium sulfate is 90-100 ℃, the pH value is usually between 4.0 and 7.0, and Pb is²⁺15 to 25 mg/L of Cu²⁺20 to 100 mg/L of Cd²⁺Is 20 to 50 mg/L.

Example 1

The anode is a graphite electrode, the cathode plate is a 316L stainless steel electrode, the mass ratio of quartz sand in sponge carbon filler filled between the 316L stainless steel electrode and the graphite electrode is 20%, and the particle size of the quartz sand 7 is 3-5 mm. The electrolytic voltage is 12.0V, and the current density is 35 mA/cm²The reaction pH was 6 and the temperature was 95 ℃. The content of heavy metal after treatment is as follows: pb²⁺0.19 mg/L, Cu²⁺Is 0.83 mg/L, Cd²⁺It was 0.31 mg/L.

Example 2

The anode is a graphite electrode, the cathode plate is a 316L stainless steel electrode, the mass ratio of quartz sand in sponge carbon filler filled between the 316L stainless steel electrode and the graphite electrode is 30%, and the particle size of the quartz sand 7 is 3-5 mm. The electrolytic voltage is 12.0V, and the current density is 35 mA/cm²The reaction pH was 6 and the temperature 98 ℃. The content of heavy metal after treatment is as follows: pb²⁺0.15 mg/L, Cu²⁺Is 0.63 mg/L, Cd²⁺It was 0.36 mg/L.

Claims

1. A purification device for heavy metal in mother liquor evaporated by ammonium sulfate is characterized by comprising a mother liquor inlet, a mother liquor outlet, a rectification power supply, a stainless steel electrode, a graphite electrode, sponge carbon filler and quartz sand, wherein the mother liquor inlet is arranged at the lower part of the electrolytic tank and is connected with an outlet of a mother liquor circulating pipeline in an ammonium sulfate evaporator; the mother liquor outlet is arranged at the upper part of the electrolytic bath and is connected with the inlet of a mother liquor circulating pipeline in the ammonium sulfate evaporator, stainless steel electrodes and graphite electrodes are arranged at intervals in the electrolytic bath, and a mixture of sponge carbon and quartz sand is filled between the stainless steel electrodes and the graphite electrodes.

2. The ammonium sulfate evaporation mother liquor heavy metal purification device as claimed in claim 1, wherein the negative electrode of the rectification power supply is connected with a stainless steel electrode, and the positive electrode of the rectification power supply is connected with a graphite electrode.

3. The apparatus as claimed in claim 1, wherein the stainless steel electrode is made of 316L stainless steel.

4. The ammonium sulfate evaporation mother liquor heavy metal purification device as claimed in claim 1, wherein in the mixture of the sponge carbon and the quartz sand, the mass ratio of the quartz sand is 20% -30%, and the particle size of the quartz sand is 3 mm-5 mm.