阅读说明：本技术 一种重金属的回收方法 (Heavy metal recovery method ) 是由 李红玲 张亚红 马红新 于 2019-03-13 设计创作，主要内容包括：本发明涉及一种重金属的回收方法,所述方法用于在电镀污泥冶炼粉尘中回收重金属,所述回收方法包括：收集冶炼粉尘；对收集的冶炼粉尘进行浆化处理,得到浆化液；从所述浆化液提取重金属。本发明中,首先对粉尘进行浆化处理,可减少粉尘挥发,避免污染空气。(The invention relates to a method for recovering heavy metals from electroplating sludge smelting dust, which comprises the following steps: collecting smelting dust; pulping the collected smelting dust to obtain pulping liquid; extracting heavy metals from the slurry. In the invention, the dust is firstly slurried, so that the dust volatilization can be reduced, and the air pollution is avoided.)

1. A method for recovering heavy metals from electroplating sludge smelting dust, which comprises the following steps:

collecting smelting dust;

pulping the collected smelting dust to obtain pulping liquid;

extracting heavy metals from the slurry.

2. The recovery method according to claim 1, wherein the collecting of the smelting dust is specifically:

and collecting smelting dust by using a dust collecting pipe.

3. The recycling method according to claim 2, wherein slurrying the collected smelting dust to obtain a slurry solution comprises:

introducing sludge squeezing water into the dust collecting pipe, and flushing the sludge squeezing water to a slurrying pool, wherein the weight ratio of the sludge squeezing water to the dust is 4: 1-3: 1;

and stirring the slurrying tank to form slurrying liquid.

4. The recycling method according to claim 3, wherein the agitating the slurry tank, after forming the slurry liquid, further comprises:

detecting the content of preset metal in the slurry to obtain a detection result, wherein the preset metal at least comprises: zn, Pb, Ni;

and processing the slurry liquid according to the detection result to obtain the processed slurry liquid.

5. The recycling method according to claim 4, wherein when the content of the predetermined metal in the slurry is less than or equal to a predetermined value, the slurry is processed according to the detection result, and the processed slurry is specifically:

and pumping the treated slurry liquid to a slurry mixing tank for stirring to obtain a stirred slurry liquid, wherein the stirring time is 40 min.

6. The recovery method of claim 5, wherein extracting heavy metals from the slurry comprises:

feeding the stirred slurry liquid into a diaphragm presser by a screw pump for dehydration treatment;

squeezing the dehydrated stirring slurry to obtain squeezed sludge;

and (3) carrying out high-temperature smelting on the squeezed sludge to obtain a first target metal, wherein the smelting temperature is 1350 ℃.

7. The recycling method according to claim 4, wherein when the content of the predetermined metal in the slurry is greater than the predetermined value, the slurry is processed according to the detection result, and the processed slurry is specifically:

and adding sulfuric acid into the treated slurry liquid for blending to obtain a blended slurry liquid.

8. The recovery method of claim 7, wherein extracting heavy metals from the slurry comprises:

filtering the prepared slurry liquid to obtain a filtrate;

electrolyzing the filtrate by using a cyclone electrolysis machine to obtain an electrolytic substance and filter residues, wherein the cathode current density range of the electrolysis machine is 500-600A/m2, and the anode current density range is 1400-1700A/m 2;

and carrying out electric furnace reduction on the filter residue to recover a second target metal.

9. A recovery method according to claim 3, characterised in that the weight ratio of sludge press water to dust is 4: 1.

10. A recovery method according to claim 3, characterised in that the weight ratio of sludge press water to dust is 3.7: 1.

11. A recovery method, according to claim 5 or 7, characterized in that said preset value is 30%.

Technical Field

The invention relates to the technical field of smart televisions, in particular to a heavy metal recovery method.

Background

The electroplating sludge belongs to the categories of HW17, HW22 and the like in national hazardous waste records, contains a large amount of heavy metal pollutants such as copper, lead, nickel, zinc, tin and the like, is mostly treated by a smelting process at present, and the sludge containing the heavy metals is dewatered by a high-strength filter, dried, smelted in a reduction furnace, and cast to obtain products such as crude copper ingots and the like. But the dust generated in the process is still rich in a large amount of metal pollutants such as lead, zinc, tin and the like, and if the dust is not properly treated, the dust can cause great harm to the environment.

Disclosure of Invention

The invention aims to solve the technical problem of environmental pollution generated in the metal recovery process in the prior art, and provides a heavy metal recovery method.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a recovery method of heavy metals for recovering heavy metals in electroplating sludge smelting dust, the recovery method comprising:

collecting smelting dust;

pulping the collected smelting dust to obtain pulping liquid;

extracting heavy metals from the slurry.

In this embodiment, the collecting of the smelting dust specifically includes:

and collecting smelting dust by using a dust collecting pipe.

In this embodiment, slurrying the collected smelting dust to obtain a slurry solution includes:

introducing sludge squeezing water into the dust collecting pipe, and flushing the sludge squeezing water to a slurrying pool, wherein the weight ratio of the sludge squeezing water to the dust is 4: 1-3: 1;

and stirring the slurrying tank to form slurrying liquid.

In this embodiment, the stirring the slurry tank to form a slurry solution further includes:

detecting the content of preset metal in the slurry to obtain a detection result, wherein the preset metal at least comprises: zn, Pb, Ni;

and processing the slurry liquid according to the detection result to obtain the processed slurry liquid so as to be convenient for squeezing.

In this embodiment, when the content of the preset metal in the slurry is less than or equal to a preset value, the slurry is processed according to the detection result, and the obtained processed slurry specifically includes:

and pumping the treated slurry liquid to a slurry mixing tank for stirring to obtain a stirred slurry liquid, wherein the stirring time is 40 min.

In this embodiment, the extracting heavy metals from the slurry comprises:

feeding the stirred slurry liquid into a diaphragm presser by a screw pump for dehydration treatment;

squeezing the dehydrated stirring slurry to obtain squeezed sludge;

and (3) carrying out high-temperature smelting on the squeezed sludge to obtain a first target metal, wherein the smelting temperature is 1350 ℃.

In this embodiment, when the content of the preset metal in the slurry is greater than the preset value, the slurry is processed according to the detection result, and the obtained processed slurry specifically includes:

and adding sulfuric acid into the treated slurry liquid for blending to obtain a blended slurry liquid.

In this embodiment, the extracting heavy metals from the slurry comprises:

filtering the prepared slurry liquid to obtain a filtrate;

electrolyzing the filtrate by using a cyclone electrolysis machine to obtain an electrolytic substance and filter residues, wherein the cathode current density range of the electrolysis machine is 500-600A/m2, and the anode current density range is 1400-1700A/m 2;

and carrying out electric furnace reduction on the filter residue to recover a second target metal.

In this example, the weight ratio of sludge press water to dust was 4: 1.

In this example, the weight ratio of sludge press water to dust was 3.7: 1.

In the present embodiment, the preset value is 30%.

According to the technical scheme disclosed by the invention, the dust is slurried firstly, so that the dust volatilization can be reduced, and the air pollution is avoided.

Drawings

FIG. 1 is a flow chart of a preferred embodiment of a heavy metal recovery method of the present invention;

FIG. 2 is a schematic diagram of the dust collection and slurrying process of a heavy metal recovery method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The method for recovering heavy metals in electroplating sludge smelting dust according to the preferred embodiment of the invention is used for recovering heavy metals in electroplating sludge smelting dust, and as shown in figure 1, the method for recovering heavy metals comprises the following steps:

step S1, collecting smelting dust;

specifically, smelting dust is collected by a dust collecting pipe, for example, fig. 2, smelting smoke is subjected to dust removal treatment by a bag-type dust remover, dust in the bag-type dust remover is introduced into the dust collecting pipe, and in the process, dust carried in cyclone, dust falling due to gravity in air and dust filtered in a quenching tower are introduced into the dust collecting pipe along with the dust. In the embodiment, the flue gas dust generated in the drying and smelting processes is subjected to gravity dust collection, cyclone dust collection and cloth bag dust collection, and the environment pollution can be reduced by adopting an economic and environment-friendly scheme of closed ash discharge and squeezing water washing size mixing.

Step S2, pulping the collected smelting dust to obtain pulping liquid;

specifically, the collected smelting dust is slurried to obtain a slurry, for example, sludge pressing water is introduced into the dust collecting pipe, and the dust in the dust collecting pipe is washed into a slurrying tank, wherein the weight ratio between the sludge pressing water and the dust is about: 4:1 to 3:1, and further, the ratio may be preferably 4:1, or 3.7:1, and may be other ratios, which is not limited herein.

Step S3, extracting heavy metals from the slurry;

specifically, the heavy metal in the slurry is extracted, and the extraction method comprises the following steps: squeezing, electric furnace reduction smelting recovery and other technologies.

In this embodiment, the collected dust is first slurried to avoid the dust volatilization and air pollution.

In a preferable scheme of this embodiment, the step S2 specifically includes:

pumping sludge squeezing water into the dust collecting pipe, and flushing the sludge squeezing water to a slurrying pool;

stirring the slurrying tank to form slurrying liquid;

further, the stirring of the slurry tank, after the slurry liquid is formed, also includes:

detecting the content of preset metal in the slurry to obtain a detection result;

specifically, the content of preset metals in the slurry is further detected, and the preset metals at least comprise: zn, Pb, Ni, etc.

Processing the slurry liquid according to the detection result to obtain the processed slurry liquid;

specifically, the slurry is processed in a corresponding mode according to the content or component of the metal in the slurry, so as to prepare for the subsequent extraction of the metal.

In a preferred embodiment of this embodiment, when the content of the preset metal in the slurry is less than or equal to the preset value, the slurry is processed according to the detection result, and the obtained processed slurry specifically includes:

pumping the treated slurry into a slurry mixing tank, stirring to obtain a stirred slurry, wherein the stirring time is 40min, for example, the content of metals such as Zn, Pb and Ni in the slurry is less than or equal to 30%, the water content is about 84%, pumping the slurry into the slurry mixing tank, and stirring for 40 min. The preset value can be set according to actual conditions, and preferably, the preset value is 30%,

further, the step S3 specifically includes:

feeding the stirred slurry into a diaphragm presser by a screw pump for dehydration treatment;

squeezing the dehydrated stirring slurry to obtain squeezed sludge (the water content is 60%);

and (3) performing high-temperature smelting on the squeezed sludge to obtain a first target metal, wherein the smelting temperature is 1350 ℃, and at the moment, the first target metal can be a crude copper ingot and the copper content is about 86%.

In another preferred embodiment of this embodiment, when the content of the preset metal in the slurry is greater than the preset value, the slurry is processed according to the detection result, and the obtained processed slurry specifically includes:

the treated slurry is mixed with sulfuric acid to obtain a mixed slurry, and the mixed slurry is mixed with sulfuric acid to obtain a mixed slurry having a pH of less than 4.

Further, the step S3 specifically includes:

filtering the prepared slurry liquid to obtain a filtrate;

electrolyzing the filtrate by using a cyclone electrolysis machine to obtain an electrolytic substance and filter residues;

reducing the filter residue by an electric furnace to recover a second target metal;

specifically, the prepared slurry is filtered by a filter press, and the filtrate enters a cyclone electrolysis machine through a delivery pump for electrolysis treatment to obtain an electrolytic substance (zinc), wherein the electrolysis conditions are as follows: the cathode current density is 500-600A/m2 at 420-500L/h, the anode current density is 1400-1700A/m 2, the zinc is separated out from the cathode, and the recovery rate of the zinc is more than 90 percent. The second target metal is a Pb and Ni mixed metal.

In this embodiment, an economical and environment-friendly scheme of closed ash discharge and squeezing water scouring and size mixing is adopted, so that water resources are saved, the purpose of treating waste by waste is achieved, and dust loss pollution is reduced.

Secondly, after scouring and size mixing are carried out on the smelting dust by adopting sludge squeezing water, different recovery processes are adopted according to different heavy metal components and concentrations, so that the heavy metals in the smelting dust are recovered economically and effectively to the greatest extent, and the aim of recycling hazardous wastes is fulfilled.

For ease of understanding, the technical solution of the present invention is described below in two examples: example 1:

(1) and (3) introducing sludge squeezing water into the dust collecting pipe, and flushing the sludge squeezing water to a slurrying pool, wherein the ratio of the sludge squeezing water to the dust is 4:1, starting stirring to prepare slurry liquid;

(2) detecting that the content of Zn, Pb, Ni and other metals in the slurrying liquid is less than or equal to 30 percent and the water content is about 84 percent, pumping the slurrying liquid to a size mixing tank, stirring for about 40min, and ensuring that the size mixing liquid is uniformly mixed so as to be convenient for squeezing;

(3) the sludge in the size mixing tank is sent to a membrane presser by a screw pump for dewatering,

(4) and (3) strongly squeezing the dewatered sludge (with the water content of 60 percent), drying, and then smelting in a smelting furnace at a high temperature (the smelting temperature is 1350 ℃) to obtain a crude copper ingot product with the copper content of about 86 percent.

Example 2:

(1) and (3) introducing sludge squeezing water into the dust collecting pipe, and flushing the sludge squeezing water to a slurrying pool, wherein the ratio of the sludge squeezing water to the dust is 3.7:1, starting stirring to prepare slurry liquid;

(2) detecting that the content of Zn, Pb, Ni and other metals in the slurry is more than 30%, and adding sulfuric acid to prepare the slurry with the pH value less than 4;

(3) after filter pressing and filtering in a filter press, the filtrate enters a cyclone electrolysis machine through a delivery pump, the cathode current density is between 500 and 600A/m2 at 420-500L/h, the anode current density is between 1400 and 1700A/m 2, zinc is separated out from the cathode, and the recovery rate of the zinc is more than 90 percent;

(4) and carrying out electric furnace reduction smelting on the filter residue to recover mixed metal Pb and Ni.

In this embodiment, an economical and environment-friendly scheme of closed ash discharge and squeezing water scouring and size mixing is adopted, so that water resources are saved, the purpose of treating waste by waste is achieved, and dust loss pollution is reduced.

Secondly, after scouring and size mixing are carried out on the smelting dust by adopting sludge squeezing water, different recovery processes are adopted according to different heavy metal components and concentrations, so that the heavy metals in the smelting dust are recovered economically and effectively to the greatest extent, and the aim of recycling hazardous wastes is fulfilled.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.