阅读说明：本技术 一种投资少见效快效益高零排放的回收利用三氯化铁蚀刻废液的方法 (Method for recycling ferric trichloride etching waste liquid with low investment, fast effect, high benefit and zero emission ) 是由 曾彬 于 2020-07-08 设计创作，主要内容包括：本发明公开了一种投资少见效快效益高零排放的回收利用三氯化铁蚀刻废液的方法,依次包括如下步骤：三氯化铁蚀刻废液泵入反应釜,加入铁粉搅拌反应,过滤；滤液泵入第二个反应釜,按镍检测含量的2.2～4倍量加入60％的工业硫化碱,过滤；镍渣投入第三个反应釜中,加入2～5倍体积的水洗涤、过滤；滤液泵入第四个反应釜搅拌,加入碱液,过滤；滤渣在第五个反应釜中经酸液复溶后通入氧化剂,过滤；滤液泵入第六个反应釜搅拌加入碱液,过滤。本发明基于更为系统性的,全面的化学分离的方法,能将三氯化铁废液中的各种成分(主要含铁镍铬铜)全部分离出来,通过控制产物中的金属含量以达到分别销售的要求,最终达到零排放的目的。(The invention discloses a method for recycling ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, and sequentially comprises the following steps: pumping the ferric trichloride etching waste liquid into a reaction kettle, adding iron powder, stirring for reaction, and filtering; pumping the filtrate into a second reaction kettle, adding 60% of industrial sodium sulfide according to 2.2-4 times of the detected nickel content, and filtering; putting the nickel slag into a third reaction kettle, adding 2-5 times of water for washing, and filtering; pumping the filtrate into a fourth reaction kettle, stirring, adding alkali liquor, and filtering; re-dissolving the filter residue in acid solution in a fifth reaction kettle, introducing an oxidant, and filtering; pumping the filtrate into a sixth reaction kettle, stirring, adding alkali liquor, and filtering. The invention is based on a more systematic and comprehensive chemical separation method, can completely separate various components (mainly containing iron, nickel, chromium and copper) in the ferric trichloride waste liquid, and can achieve the requirement of respective sale by controlling the metal content in the product, thereby finally achieving the purpose of zero emission.)

1. A method for recycling ferric trichloride etching waste liquid with less investment, quick effect, high benefit and zero emission is characterized in that: the method sequentially comprises the following steps:

s1, pumping the ferric trichloride etching waste liquid into a reaction kettle, adding iron powder, stirring for reaction, controlling the end point PH to be 1-4, and filtering the solution, wherein the copper content of the solution is less than 200 mg/L;

s2, pumping the filtrate obtained in the step 1 into a second reaction kettle, adding 60% of industrial sodium sulfide (prepared into a 20-50% solution) in an amount which is 2.2-4 times of the detected nickel content, controlling the nickel content in the solution to be less than 100mg/L at the end point, and filtering;

s3, putting the nickel slag obtained in the step 2 into a third reaction kettle, adding 2-5 times of water to control the PH value to be 1-4, washing, and filtering;

s4, pumping the filtrate obtained in the step 3 into a fourth reaction kettle, stirring, adding alkali liquor to adjust the pH to 3-6, controlling the chromium content in the solution to be less than 100mg/L at the end point, and filtering;

s5, redissolving the filter residue obtained in the step 4 in acid liquor in a fifth reaction kettle, introducing an oxidant, controlling the content of ferrous ions at the end point of the reaction to be 2-10g/L, and putting the filtered iron residue into the first reaction kettle for treatment and utilization;

s6, pumping the filtrate obtained in the step 5 into a sixth reaction kettle, stirring, adding alkali liquor to adjust the pH to be 5-7, and filtering to obtain filtrate serving as washing water of the third reaction kettle.

2. The method for recycling the ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, according to claim 1, is characterized in that: the filtration in the method step of recycling the ferric trichloride etching waste liquid adopts plate-and-frame filtration.

3. The method for recycling the ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, according to claim 1, is characterized in that: the PH value in the step 1 is preferably 2-3, the PH value in the step 3 is preferably 3-4, and the PH value in the step 4 is preferably 5-6.

4. The method for recycling the ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, according to claim 1, is characterized in that: the oxidant added in the step 5 is any one of air, ozone, sodium chlorate, sodium hypochlorite and hydrogen peroxide.

5. The method for recycling the ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, according to claim 1, is characterized in that: and (4) controlling the feeding speed in steps 2 and 4 to be 10-30L/min.

6. The method for recycling the ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, according to claim 1, is characterized in that: the feeding mode in the step 2 and the step 4 adopts spray feeding.

Technical Field

The invention relates to the technical field of comprehensive recycling and environmental protection of ferric trichloride etching waste liquid, in particular to a method for recycling ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission.

Background

A factory for etching stainless steel or copper by using ferric trichloride as an etching agent continuously generates black brown ferric trichloride etching waste liquid after etching for a period of time, and a large amount of heavy metals (copper, nickel, chromium and the like) can be accumulated in the etching waste liquid to influence normal etching work, at this time, a new etching liquid needs to be replaced, and the replaced waste etching liquid can be discharged after being treated to reach a discharge standard. The existing method for treating the ferric trichloride etching waste liquid generally comprises an electrolytic method and an extraction method, wherein the electrolytic method is used for separating various metal elements by controlling electrolytic current according to different electrolytic potentials of different metals, and the method has the obvious defects of high energy consumption, potential safety hazard caused by the fact that a by-product chlorine is extremely toxic, and products cannot be completely separated; the extraction method achieves the separation purpose according to different distribution coefficients of different metal elements in an extractant, and has the defects that the extractant is easy to be poisoned, the cost is high, and the purpose of completely separating various metal elements is not easy to achieve;

in addition, a chemical separation method for separately separating certain impurities is provided, but the chemical separation method is local and has no systematicness, the problem of waste discharge of an etching plant cannot be completely solved, the separated products cannot meet the sales standard, the dangerous waste is inevitably generated, and the high-price dangerous waste disposal cost is still paid; even some manufacturers directly neutralize the waste liquid with alkali to precipitate all metal elements as dangerous waste, which wastes resources and pays a large amount of dangerous waste disposal fees. In summary, the existing method has high investment and cost and always generates hazardous wastes, and the high-price hazardous waste disposal fee is paid.

In order to solve the problems, the scheme is developed accordingly.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a method for recycling ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, solves the problem of worries after waste discharge of various etching factories, realizes zero emission of waste, does not need to pay high hazardous waste disposal cost, and creates great economic benefit and social benefit for companies.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a method for recycling ferric trichloride etching waste liquid with less investment, quick effect, high benefit and zero emission sequentially comprises the following steps:

s1, pumping the ferric trichloride etching waste liquid (wherein sludge generated after acid washing water after washing a plate is neutralized by alkali is dissolved by acid and then is treated the same as the waste liquid) into a reaction kettle, adding iron powder for stirring reaction, controlling the end point PH to be 1-4, filtering the solution to obtain copper-containing solution with the copper content of less than 200mg/L, and directly selling the copper slag;

s2, pumping the filtrate obtained in the step 1 into a second reaction kettle, adding 60% of industrial sodium sulfide (prepared into a 20-50% solution) in an amount which is 2.2-4 times of the detected nickel content, controlling the nickel content in the solution to be less than 100mg/L at the end point, and filtering;

s3, putting the nickel slag obtained in the step 2 into a third reaction kettle, adding 2-5 times of water to control the PH value to be 1-4, washing, and filtering, wherein the nickel content of the filtered nickel slag is more than 10% and the nickel slag can be directly sold;

s4, pumping the filtrate obtained in the step 3 into a fourth reaction kettle, stirring, adding alkali liquor to adjust the pH to 3-6, controlling the chromium content in the solution to be less than 100mg/L at the end point, filtering, adding an oxidant into the filtrate, concentrating and crystallizing to prepare an iron trichloride product for sale, wherein the iron content of the filtrate is more than 10 percent and the filtrate can be directly sold as a water purifying agent;

s5, re-dissolving the filter residue obtained in the step 4 in acid in a fifth reaction kettle, introducing an oxidant, controlling the content of ferrous ions at the end point of the reaction to be 2-10g/L, and putting the filtered iron residue into the first reaction kettle for treatment and utilization;

s6, pumping the filtrate obtained in the step 5 into a sixth reaction kettle, stirring, adding alkali liquor, adjusting the pH to 5-7, filtering, directly selling the filter residues serving as the raw material of the chrome brick, and using the filtrate as washing water of the third reaction kettle.

Preferably, the filtration in the method for recycling the ferric trichloride etching waste liquid adopts plate-and-frame filtration.

Preferably, the pH value in the step 1 is preferably pH2-3, the pH value in the step 3 is preferably pH3-4, and the pH value in the step 4 is preferably pH 5-6.

Preferably, the oxidant introduced in step 5 is any one of air, ozone, sodium chlorate, sodium hypochlorite and hydrogen peroxide.

Preferably, the feeding speed in the step 2 and the feeding speed in the step 4 are both controlled to be 10-30L/min.

Preferably, the feeding mode in step 2 and step 4 is spray feeding.

(III) advantageous effects

After adopting the technical scheme, compared with the prior art, the invention has the following advantages: the invention relates to a method for recycling ferric trichloride etching waste liquid, which has the advantages of low investment, quick effect, high benefit and zero emission, and is based on a more systematic and comprehensive chemical separation method, wherein various components (mainly containing iron, nickel, chromium and copper) in the ferric trichloride etching waste liquid (including sludge obtained by neutralizing acid liquor obtained after plate washing with alkali) are completely separated, and the metal content in the product is controlled to meet the requirement of respective sale, so that the aim of zero emission is finally achieved. Meanwhile, aiming at the efficient treatment of solid waste and liquid waste after etching by etching manufacturers, the zero emission of three wastes is realized, a large amount of hazardous waste disposal cost is saved, and worries of all etching manufacturers are perfectly solved.

Drawings

FIG. 1 is a flow chart of the method for recycling ferric trichloride etching waste liquid according to the present invention;

FIG. 2 is a schematic view of a spray feeder of the present invention;

Detailed Description

The invention is explained in more detail below with reference to the figures and examples.

A method for recycling ferric trichloride etching waste liquid with less investment, quick effect, high benefit and zero emission sequentially comprises the following steps:

step 1, pumping ferric trichloride etching waste liquid (wherein sludge generated after acid washing water after plate washing is neutralized by alkali is treated by acid and then treated with the same as the waste liquid) into a reaction kettle, adding iron powder, stirring for reaction, controlling the end point PH1-4, preferably PH2-3, controlling the copper content of the solution to be less than 200mg/L, filtering by a plate-and-frame filter, and directly selling copper slag;

step 2, pumping the filtrate into a second reaction kettle, adding 60 percent of industrial sodium sulfide (prepared into a 20-50 percent solution) according to 2.2-4 times of the tested content of nickel, controlling the feeding speed at 10-30L/min, and controlling the nickel content in the solution to be less than 100mg/L at the end point;

step 3, putting the filtered nickel slag into a third reaction kettle, adding 2-5 times of water to control the PH1-4 to wash, preferably selecting the PH3-4, wherein more than 10% of the filtered nickel can be directly sold;

step 4, pumping the filtrate into a fourth reaction kettle, stirring, adding alkali liquor to adjust the pH of 3-6, preferably 5-6, controlling the feeding speed to be 10-30L/min, controlling the chromium content in the solution to be less than 100mg/L at the end point, directly selling the filtrate as a water purifying agent, and adding an oxidant to concentrate and crystallize according to the situation to prepare an iron trichloride product for sale;

step 5, after the slag is redissolved in a fifth reaction kettle, introducing air or ozone or other oxidants such as sodium chlorate, sodium hypochlorite, hydrogen peroxide and the like, controlling the content of ferrous ions at the end point of the reaction to be 2-10g/L, and putting the filtered iron slag into the first reaction kettle for treatment;

and 6, pumping the filtrate into a sixth reaction kettle, stirring, adding alkali liquor to adjust the pH of the mixture to 5-7, directly selling the filter residues serving as the raw material of the chrome brick, and using the filtrate as washing water of the third reaction kettle.

The present invention will be described in more detail below with reference to examples set forth herein. These examples are provided only for illustrating the present invention and should not be construed as limiting the scope of the present invention.