阅读说明：本技术 一种福美渣的回收利用方法 (Method for recycling Fumei slag ) 是由 张海军 潘从明 杨瑛 于 2021-10-12 设计创作，主要内容包括：本发明提供一种福美渣的回收利用方法。采用硫化沉淀转化剂与福美渣发生液固相反应,不仅使其中稳定常数相对较小的福美金属盐沉淀转化为相应金属硫化物沉淀而易于后续分离,而且使相应的福美根转化为水溶的福美盐而分离,能够绿色、高效地回收有机成分福美根再利用,有效避免了该有机物对环境造成的危害。本发明优选将反应后经固液分离得到的固体渣经酸洗回收所含金属,尤其是回收其中高附加值的钴,实现了福美渣中的多种有色金属的分离、回收利用。(The invention provides a recycling method of Fumei slag. The adoption of the liquid-solid phase reaction between the vulcanization precipitation converting agent and the thiram slag not only enables the thiram metal salt with relatively small stability constant to be converted into corresponding metal sulfide precipitation for easy subsequent separation, but also enables the corresponding thiram root to be converted into water-soluble thiram salt for separation, can recycle the organic component thiram root in a green and high-efficiency manner and effectively avoids the harm of the organic matter to the environment. The invention preferably recycles the contained metal, especially the cobalt with high added value, from the solid slag obtained by solid-liquid separation after the reaction through acid cleaning, thereby realizing the separation and recycling of various nonferrous metals in the Fumei slag.)

1. The method for recycling the thiram slag is characterized in that the thiram slag is precipitated solid slag formed by the reaction of thiram salt and metal ions; the method is characterized in that: carrying out liquid-solid reaction on the thiram slag and a vulcanization precipitation conversion agent in a water system, carrying out solid-liquid separation after the reaction, wherein the liquid obtained by the separation is mainly a water-soluble thiram salt solution;

the sulfide precipitation transforming agent is S-containing^2-Ions or capable of dissociating S^2-Ionic compounds or mixtures.

2. The recycling method according to claim 1, wherein: the metal ions comprise one or more than one of manganese, cobalt, zinc and cadmium.

Preferably, the thiram slag is generated when the thiram salt is used for removing impurities in the zinc electrolysis or manganese electrolysis process.

3. The recycling method according to claim 1, wherein: the sulfide precipitation converting agent includes but is not limited to Na₂S、K₂S、(NH₃)₂S、Na₂S_x(2≤x≤6)、K₂S_y(2≤y≤6)、(NH₃)₂S_z(2≤z≤6)。

4. The recycling method according to claim 1, wherein: the reaction temperature is 0-100 ℃, and preferably 5-80 ℃;

preferably, the reaction time is from 5 minutes to 5 hours, preferably from 10 minutes to 1 hour.

5. The recycling method according to claim 1, wherein: s in the sulfide precipitation transforming agent^2-The mol ratio of the ions to the thiram roots in the thiram slag is (0.1-10): 1, preferably 1: 1;

preferably, the sulfide precipitation transforming agent is added to the reaction system in the form of solid, suspension or solution.

6. The recycling method according to claim 1, wherein: the water-soluble thiram salt solution is directly used for an impurity removal process, or is concentrated to obtain thiram salt, and the thiram salt is crystallized and then is recycled.

7. The recycling method according to any one of claims 1 to 6, wherein: after the solid-liquid separation, the solid slag is subjected to acid washing separation to recover the metal ions;

preferably, the solid slag is subjected to sectional acid washing to separate and recover the metal ions.

8. The recycling method according to claim 7, wherein: the acid used in the acid cleaning comprises one or more of sulfuric acid, hydrochloric acid, nitric acid and perchloric acid;

preferably, the acid washing process comprises low acidity atmospheric pressure oxidation leaching and pressure oxidation leaching;

preferably, the oxidizing agent used in the low acidity atmospheric and pressure oxidation leaching comprises persulfate (S)₂O₈ ^2-)、H₂O₂、MnO₂、O₂One or more of them.

9. The recycling method according to claim 7, wherein: dissolving cobalt fumarate in cobalt fumarate slag by using mixed acid of sulfuric acid and concentrated nitric acid, and heating to remove nitrate radicals to obtain a cobalt sulfate solution.

10. The recycling method according to claim 7, wherein: calcining cobalt furoxide in the furoxide slag to obtain cobalt oxide;

preferably, the calcination temperature is preferably 400 ℃ to 800 ℃;

preferably, the calcination time is preferably 0.5h to 6 h.

Technical Field

The invention belongs to the field of solid waste treatment, and particularly relates to a method for recycling Fumei slag.

Background

In the hydrometallurgical process, in order to improve the defects of the existing impurity removal process, a novel impurity removal method is proposed: organic N, N dimethyl dithiocarbamate (fomesalt) impurity removal method.

For example, in the electrolytic manganese production process, sodium ferometalate is used for removing heavy metal ions such as Co, Ni and Cu by precipitation, and the method has the advantages of good impurity removal effect, easiness in separation of the precipitate and the like.

In addition, in the hydrometallurgical zinc process, as zinc enters the leachate in the form of zinc sulfate, other impurities, such as elements Cu, Cd, Co, Ni, etc., also enter the solution. If the content of the impurities is too high, the zinc electrowinning process and quality can be greatly influenced. For this reason, the purification of zinc sulfate leachate is one of the most important and indispensable processes for zinc hydrometallurgy. The traditional purification cobalt and nickel removal process mainly adopts a zinc powder replacement method, but along with the reduction of the quality of zinc concentrate, the content of impurities such as cobalt and nickel is higher and higher, so that the problems of high zinc powder consumption, high steam cost, poor system stability, easy impurity redissolution and difficult filtration are caused, and the problem that the self-produced alloy zinc powder cannot meet the production requirement under the high cobalt raw material is gradually shown. Therefore, the purification of zinc sulfate leaching solution by utilizing the thiram salt is rapidly developed and applied.

During the impurity removal process of the thiram salt, a large amount of thiram slag solid waste is generated. The waste residue has flammable and explosive properties, contains toxic heavy metals such as cadmium and cobalt, can cause long-term adverse effects on aquatic environment, belongs to strictly-controlled dangerous solid waste, has certain potential safety and environmental protection hazards in long-term storage, and must be properly treated and disposed. However, at present, because an effective subsequent treatment process is not available, the fumei slag is piled and placed by a plurality of manufacturers, which not only causes resource waste, but also occupies land resources, causes certain potential safety and environmental protection hazards due to long-term piling, and needs to be properly treated and disposed. On the other hand, the Fumei slag contains metal resources such as zinc, cadmium, cobalt, copper and the like, wherein cobalt is a strategic non-ferrous metal with high value, the cobalt has irreplaceable effect in emerging fields such as batteries and the like, and the price of electrolytic cobalt is basically maintained at about 25-40 ten thousand yuan/ton, even once reaching 80 ten thousand yuan/ton.

In recent years, the technology for recycling the fomes slag is concerned and reported. For example, patent document CN110205482A discloses a comprehensive recovery method of cobalt-removing slag of zinc smelting organic matter; patent document CN110358917A discloses a process for treating sodium cobalt ferulate slag. However, most of these processes focus on the recycling of nonferrous metals, such as obtaining nonferrous metals by direct calcination, or removing organic substances by acid dissolution and then separating and recycling the obtained nonferrous metals, and there are few reports on the recycling of environmentally harmful formalin organic substances.

Disclosure of Invention

Aiming at the technical current situation, the invention aims to provide a method for recycling thiram slag, which can be used for green and high-efficiency recycling of thiram organic matters and effectively avoid the harm of the organic matters to the environment.

In order to achieve the above technical objects, the present inventors have found through extensive experimental studies that a precipitate of a fomite metal salt having a relatively small stability constant and a precipitate of a fomite metal salt having S content in a fomite slag containing a plurality of fomite metal salts (e.g., fomite cobalt (Co), fomite zinc (Zn), fomite cadmium (Cd), etc.) formed by reacting a fomite salt (N, N-dimethyldithiocarbamate) with a plurality of metal ions^2-Ions or capable of dissociating S^2-When the ionic compound or mixture is mixed, it can be converted into corresponding metal sulfide precipitate, in which the foment can be converted into water-soluble fomes salt and separated and recovered, said S-containing^2-Ions or capable of dissociating S^2-The ionic compound or mixture can be called a vulcanization precipitation converting agent, and the cobalt formol with better stability can not react with the vulcanization precipitation converting agent.

For example, when the sulfide precipitation converting agent is Na₂S, the reaction equation is as follows:

M(C₃H₆NS₂)₂+Na₂S＝＝MS↓+2NaC₃H₆NS₂and M is a metal,such as Zn, Cd, etc.

Therefore, the inventor firstly reacts the thiram slag with the vulcanization precipitation transforming agent in a water system, solid-liquid separation is carried out after the reaction, and the liquid obtained by the separation is mainly water-soluble thiram salt solution.

Namely, the technical scheme provided by the invention is as follows: a method for recycling Fomet slag, wherein the Fomet slag is precipitated solid slag formed by the reaction of Fomet salt (N, N-dimethyl dithiocarbamate) and metal ions; the method is characterized in that: carrying out liquid-solid reaction on the thiram slag and a vulcanization precipitation conversion agent in a water system, carrying out solid-liquid separation after the reaction, and separating to obtain a liquid which is a water-soluble thiram salt solution; the sulfide precipitation transforming agent is S-containing^2-Ions or capable of dissociating S^2-Ionic compounds or mixtures.

The thiram slag is not limited, and comprises one or more of thiram manganese, thiram cobalt, thiram zinc (Zn), thiram cadmium (Cd) and the like.

The source of the thiram slag is not limited, and the thiram slag is generated by removing impurities by using thiram salt in the processes of zinc electrolysis, manganese electrolysis and the like.

The sulfide precipitation transforming agent is not limited and comprises Na₂S、K₂S、(NH₃)₂S、Na₂S_x(2≤x≤6)、K₂S_y(2≤y≤6)、(NH₃)₂S_z(2. ltoreq. z. ltoreq.6), and Na is preferred in view of economic cost₂S。

Preferably, the reaction temperature is 0 to 100 ℃, more preferably 5 to 80 ℃.

Preferably, the reaction time is 5 minutes to 5 hours, and more preferably 10 minutes to 1 hour.

The amount of sulphurized precipitation converting agent used depends on the S content of the precipitation converting agent or the ability to dissociate S^2-Ion number adjustment, S^2-The mol ratio of the ions to the thiram roots in the thiram slag is preferably (0.1-10): 1, more preferably 1: 1.

the reaction is carried out in a water phase environment, wherein the Fumei slag is pulped, and the addition form of the vulcanization precipitation transforming agent is not limited and can be solid, suspension, solution and the like.

Preferably, after the solid-liquid separation, the solid slag is subjected to acid washing to recover the contained metals, and more preferably, the contained metals are gradually recovered by adopting sectional acid washing to separate the cobalt with high added value from other metals, such as zinc, cadmium and the like, namely, the other metals are firstly formed into soluble salts, and the cobalt slag is solid and precipitated. The acid used in the acid washing is not limited, and includes one or more of sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, and the like. The acid washing process is not limited, and comprises low acidity atmospheric pressure oxidation leaching, sectional washing by controlling different acidity, pressure oxidation leaching and the like. The oxidant used in the low acidity atmospheric pressure oxidation leaching and the pressure oxidation leaching is not limited, and comprises persulfate (S)₂O₈ ^2-)、H₂O₂、MnO₂、O₂。

As a preferred implementation mode, mixed acid of sulfuric acid and concentrated nitric acid is adopted to dissolve cobalt formiate slag, nitrate radicals are removed through heating, and cobalt sulfate solution is obtained.

As another preferred implementation, the cobalt oxide slag is calcined to obtain cobalt oxide. The calcination temperature is preferably 400-800 ℃, and the calcination time is preferably 0.5-6 h.

Preferably, the thiram salt solution can be directly reused in impurity removal processes in electrolytic zinc, electrolytic manganese and the like, or can be concentrated to obtain thiram salt, and the thiram salt is crystallized and reused.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention adopts the reaction between the sulfuration precipitation transforming agent and the thiram slag, not only converts the thiram metal salt precipitation with relatively small stability constant into the corresponding metal sulfide precipitation for easy subsequent separation, but also converts the thiram root into the water-soluble thiram salt for separation, can recycle the thiram root in a green and high-efficiency way, and effectively avoids the harm of the organic matter to the environment. And the recovered thiram organic matters can be reused in a deslagging process, so that the cyclic utilization is achieved, the economic benefit is increased, and the harm to the environment caused by the emission of the organic matters and elements in the organic matters is effectively avoided.

(2) The invention preferably carries out acid cleaning on solid slag obtained by solid-liquid separation after reaction, recovers the contained metal, particularly recovers the cobalt with high added value, thereby realizing the separation and recycling of various nonferrous metals in the Fumei slag.

Drawings

FIG. 1 is a schematic view of the process for recovering Fomet slag in example 1 of the present invention.

FIG. 2 is a schematic view of the process for recovering Fomet slag in example 2 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following examples and drawings, which are not intended to limit the invention to the details shown.

Example 1:

in this example, the chemical composition analysis (unit:%) of the fomes slag is shown in the following table:

the treatment as shown in figure 1 was carried out on the slag having the chemical composition indicated in the above table:

(1) 31.70g of thiram slag (containing 15g of thiram root in terms of sodium thiram dihydrate) is pulped with 100mL of water, 30.00g of sodium sulfide nonahydrate is added, and after reaction for 2 hours at 85 ℃, filtration is carried out. The filtrate is distilled under reduced pressure to be dry to obtain 7.1g of sodium thiram dihydrate, the yield of the organic thiram is 47.3 percent, and the sodium thiram dihydrate can be reused in the purification and cobalt removal process for producing metal zinc by an electrolytic method. The filtered solid slag is treated in the following step (2).

(2) Leaching the solid slag by using 150mL of 100g/L sulfuric acid to obtain a zinc-containing solution, wherein the yield of zinc is 89.2%; then leaching with 20mL of sulfuric acid of 500g/L to obtain a solution containing cadmium, wherein the yield of the cadmium is 86.9%; the tail gas is absorbed by 250mL of 40g/L sodium hydroxide aqueous solution and then can be returned to the step (1) for reuse. The undissolved slag in the process is treated in the following step (3).

(3) Using 20mL of the undissolved slag, wherein the volume ratio is 20: 1, dissolving 500g/L sulfuric acid and concentrated nitric acid, heating to drive off nitrate radicals to obtain a cobalt sulfate solution, wherein the yield of cobalt is 87.7 percent, and the molar weight of cobalt in the cobalt sulfate solution is as follows: the sum of the molar amounts of zinc and cadmium is 6.27: 1.

example 2:

in this example, the thiram slag of example 1 was used, that is, the chemical composition content thereof was the same as that of example 1.

The fomes slag was treated as shown in fig. 2:

(1) 31.70g of thiram slag (containing 15g of thiram root in terms of sodium thiram dihydrate) is taken, pulped by 300mL of water, 24.00g of sodium sulfide nonahydrate is added, and after reaction for 2 hours at 70 ℃, filtration is carried out. The filtrate is distilled under reduced pressure to be dry to obtain 6.9g of sodium thiram dihydrate, the yield of the organic thiram root is 46 percent, and the sodium thiram dihydrate can be reused in the purification and cobalt removal process for producing metal zinc by an electrolytic method. The filtered solid slag is treated in the following step (2).

(2) The solid residue was first slurried with 30mL of water and then 13.00g of MnO₂And 25mL of 6.00mol/L sulfuric acid is subjected to atmospheric pressure oxidation leaching at 70 ℃ for 6 hours to obtain a solution containing zinc and cadmium, wherein the yields of the zinc and the cadmium are respectively 79.5% and 76.7%. The undissolved slag in the process is treated in the following step (3).

(3) The undissolved residue was vacuum filtered at 130 ℃ to obtain 3.15g of sulfur. And calcining the residue in a muffle furnace at 600 ℃ for 2 hours to obtain 0.98g of cobaltosic oxide solid, wherein the yield of cobalt is 87%, and the mass of cobalt in the cobaltosic oxide is as follows: mass sum of zinc and cadmium 71: 1.

example 3:

in this example, the thiram slag of example 1 was used, that is, the chemical composition content thereof was the same as that of example 1.

The treatment method of the thiram slag is basically the same as that of the example 2, except that:

in the step (1), the reaction temperature is 10 ℃, the reaction time is 5 hours, 6.1g of sodium thiram dihydrate is obtained, and the yield of the organic thiram is 40.67%.

In the step (2), 35.00g of Na is used for solid slag₂S₂O₈And 40.00mL 6Oxidizing and leaching 00mol/L concentrated sulfuric acid at 70 ℃ for 6h under normal pressure to obtain a solution containing zinc and cadmium, wherein the yield of the zinc and the yield of the cadmium are respectively 89.1% and 88.7%.

In the step (3), the undissolved residue is subjected to heat preservation and suction filtration at 130 ℃ to obtain 1.6g of sulfur. And calcining the residue in a muffle furnace at 600 ℃ for 2 hours to obtain 0.91g of cobaltosic oxide solid, wherein the yield of cobalt is 80.7%, and the mass of cobalt in the cobaltosic oxide is as follows: mass sum of zinc and cadmium 77: 1.

example 4:

in this example, the thiram slag of example 1 was used, that is, the chemical composition content thereof was the same as that of example 1.

The treatment method of the thiram slag is basically the same as that of the example 2, except that:

in the step (1), the reaction temperature is 100 ℃, the reaction time is 20 minutes, 6.8g of sodium thiram dihydrate is obtained, and the yield of the organic thiram is 45.33%.

In the step (2), 50.00mL of 30% H is used for solid slag₂O₂And 50.00mL of 6.00mol/L concentrated sulfuric acid is subjected to atmospheric pressure oxidation leaching at 70 ℃ for 6 hours to obtain a solution containing zinc and cadmium, and the yield of the zinc and the yield of the cadmium are respectively 87.3 percent and 86.5 percent.

In the step (3), the undissolved slag is calcined in air at 600 ℃ for 2 hours by a muffle furnace to obtain 0.92g of cobaltosic oxide solid, the yield of cobalt is 81.6%, and the mass of cobalt in the cobaltosic oxide is as follows: the mass sum of zinc and cadmium is 80: 1.

example 5:

in this example, the thiram slag of example 1 was used, that is, the chemical composition content thereof was the same as that of example 1.

The treatment method of the thiram slag is basically the same as that of the example 2, except that:

in the step (2), the solid slag and 50.00mL of 6.00mol/L concentrated sulfuric acid are transferred into a pressure reaction kettle, the pressure oxidation leaching is carried out for 2h under the oxygen pressure of 1.3MPa at the temperature of 100 ℃, the solution containing zinc and cadmium is obtained after pressure relief, and the yield of zinc and cadmium is 84.6 percent and 76.3 percent respectively.

In the step (3), the undissolved residue is subjected to heat preservation and suction filtration at 130 ℃ to obtain 3.3g of sulfur. And calcining the residual slag in a muffle furnace at 600 ℃ for 2 hours to obtain 0.85g of cobaltosic oxide solid. The yield of cobalt is 75.4%, and the mass of cobalt in cobaltosic oxide is as follows: mass sum of zinc and cadmium 56: 1.

the embodiments described above are intended to illustrate the technical solutions of the present invention in detail, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modification, supplement or similar substitution made within the scope of the principles of the present invention should be included in the protection scope of the present invention.