CN108193251B

CN108193251B - System and method for recovering nickel-tin salt coloring and medium-temperature hole sealing agent in aluminum processing

Info

Publication number: CN108193251B
Application number: CN201711471644.9A
Authority: CN
Inventors: 熊映明
Original assignee: FOSHAN SANSHUI XIONGYING INNOVATIVE CENTER FOR ALUMINUM SURFACE TECHNOLOGIES Co Ltd
Current assignee: FOSHAN SANSHUI XIONGYING INNOVATIVE CENTER FOR ALUMINUM SURFACE TECHNOLOGIES Co Ltd
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2020-01-14
Anticipated expiration: 2037-12-29
Also published as: CN108193251A

Abstract

The invention discloses a nickel-tin salt coloring and intermediate temperature hole sealing agent recovery system and method in aluminum processing, which sequentially comprise a nickel-tin-containing wastewater interception unit, a nickel-tin-containing wastewater collection unit, a tin ion recovery unit and a nickel ion recovery unit from upstream to downstream, wherein the nickel-tin-containing wastewater interception unit comprises a 13# nickel-tin salt coloring tank, a 14# flowing water washing tank, a 15# high-pressure atomization spraying tank, a 16# intermediate temperature hole sealing tank, a 17# flowing water washing tank and an 18# flowing water washing tank which are sequentially arranged. The method is used for oxidizing, coloring and sealing the toxic waste residues containing nickel and tin generated in the aluminum processing, and ensures that the recovered products containing nickel and tin are recycled to a 13# nickel-tin salt coloring tank by utilizing an online classification recycling and compatible method, selecting medicament components and skillfully configuring a system, thereby realizing the recycling of toxic waste. The method can be used for treating about 1600 ten thousand tons of nickel-tin-containing wastewater generated by oxidizing, coloring and sealing holes in aluminum processing on line, converting about 4 ten thousand tons of toxic waste residues containing nickel and tin, and generating about 10 ten thousand tons of nickel-tin salt colorant.

Description

System and method for recovering nickel-tin salt coloring and medium-temperature hole sealing agent in aluminum processing

Technical Field

The invention relates to the field of aluminum processing, in particular to a system and a method for recovering a nickel-tin salt coloring agent and medium-temperature hole sealing agent in aluminum processing.

Background

The aluminum and the aluminum alloy have the advantages of excellent processing performance, good corrosion resistance, beautiful surface, high recovery rate and the like, are widely applied to the industries of buildings, transportation, machinery, electric power and the like, and have more obvious trend of expanding the application of the aluminum by replacing the steel with the aluminum in recent years. The aluminum processing industry is a traditional industry, and more particularly, the sunrise industry which is full of bobby vitality. According to statistics, developed countries in Europe and America consume more than 32kg of aluminum materials per year, but China only has about 13kg of aluminum materials per year and is only about one third of developed countries, and domestic aluminum material consumption has huge growth space, but under the new economic normal state, the problems of high energy consumption, large total pollution discharge amount and low resource recovery rate also become bottlenecks and obstacles for industry development.

The production in the aluminum industry comprises the working procedures of electrolysis, casting, pressure processing, surface treatment and the like, and waste water and waste residues are generated in different degrees in all the working procedures during production. A large amount of aluminum ash is generated during electrolysis and casting, alkaline waste liquid of a die is produced in the extrusion process, and various waste water and waste residues containing acid, alkali, treatment agents, chromium, nickel heavy metal ions and other complex components are generated in the surface treatment process.

(I) source of waste residues from aluminum industry

1. Electrolytic casting of aluminium ash

The aluminum ash is generated in the processes of electrolysis, smelting and casting of aluminum and aluminum alloy, and the total loss of aluminum caused by the aluminum ash is 1-12%. About 20-40kg of aluminum ash is generated when one ton of raw aluminum is processed, the amount of aluminum liquid generated during direct casting is less, the amount of aluminum ingot is more during remelting, and about 100-250kg of aluminum ash is generated during regeneration of one ton of waste aluminum. The aluminum ash can be divided into two types: one is primary aluminum ash, which is scum and skimming produced in the processes of electrolyzing raw aluminum, casting and the like without adding salt flux, and the like, and mainly comprises metal aluminum and aluminum oxide, wherein the content of aluminum can reach 15-70 percent, and the color is white; the other is secondary aluminum ash, which is the waste after the primary aluminum ash is subjected to aluminum extraction and recovery, and the aluminum content is lower than that of the primary aluminum ash, and the secondary aluminum ash is generally gray black. The secondary aluminum ash has complex components and contains toxic and harmful components such as metallic aluminum (5-30%), aluminum oxide (30-70%), silicon dioxide and ferric oxide (5-15%), potassium, sodium, calcium and magnesium chloride (10-30%) and nitrogen, fluorine, arsenic and the like. FIG. 1 shows the component detection report of aluminum ash. The aluminum ash is referred to as secondary aluminum ash.

The national electrolytic aluminum yield is 3250 ten thousand tons in 2016, the aluminum product yield of extrusion and calendering exceeds 2000 ten thousand tons, the conservative estimation of the aluminum ash amount in the whole country every year is more than 200 ten thousand tons, and the total amount of the aluminum ash is considered to be 850 ten thousand tons in 600 days. The aluminum ash is a renewable resource and has higher comprehensive recycling value, but the aluminum ash is not paid enough attention all the time, so that huge resource waste is caused. Meanwhile, the aluminum ash contains toxic and harmful substances such as fluoride, ammonia nitrogen, arsenic and the like, and is classified as dangerous waste, the waste category of the aluminum ash in 'national dangerous waste record' of 2016 edition is HW48, and the dangerous characteristic T (danger) -toxic dangerous waste. At present, the recovery of the aluminum ash in China is still in a starting stage, a recovery method which is mature, reliable and good in economical efficiency is lacked, the aluminum ash treatment recovery rate is low, the energy consumption and the waste are large, and the utilization approaches are few. In 2018, the environmental protection tax Law of the people's republic of China, which is applied from 1 month and 1 day, stipulates that an aluminum ash emission enterprise will pay an environmental protection tax of 1000 yuan/ton.

2. Extrusion surface treatment of waste water and waste residue

The production of aluminum products consumes a large amount of water, at least 15 tons of water are consumed for producing 1 ton of aluminum materials, 1000 ten thousand tons of extruded materials are produced in the whole industry every year, nearly 3 hundred million tons of waste water are discharged, about 300 ten thousand tons of waste residues are produced after the waste water is treated, and the quantity is extremely remarkable.

2.1 extruding the waste liquid, waste water and waste residue of the pot mold

After the aluminum profile extrusion die is used, the aluminum profile extrusion die is put into high-concentration alkali liquor to be die-stewed, and aluminum in a die cavity is corroded. The concentration of sodium hydroxide in the mold-boiling liquid reaches 250-350g/L, the content of aluminum ions is continuously increased along with the reaction, and when the concentration reaches above 60-70g/L and the reaction speed is obviously reduced, the mold-boiling waste liquid needs to be discharged. The treatment of the waste liquid of the die-stewing generally adopts a mode of treating waste by waste: the waste acid generated in the oxidation process is neutralized, the amount of waste residues generated by the treatment mode is very large, and the die-cooking waste residues can account for about 30% of the total amount of the slag of an enterprise. Enterprises do not utilize the economic value of the waste water, but increase the cost, and the treatment of waste water and waste residue becomes a heavy burden for environmental protection.

2.2 surface treatment of waste Water and slag

Aluminum materials are subjected to surface treatment in order to enhance corrosion resistance and decorative properties. Common surface treatment methods include anodic oxidation coloring, electrocoating, powder spraying, fluorocarbon paint spraying, and the like. The surface treatment process produces large amounts of wastewater of complex composition.

The waste water and waste residue of the anodic oxidation and electrophoretic painting processes are divided according to the processes as follows: the alkaline waste water and waste residue generated by the alkaline etching solution account for 20 percent of the total residue; acid waste water and waste residues generated by the oxidation liquid account for 30 percent of the total residue; the acid waste water and waste residue produced in the spraying procedure account for 20 percent of the total residue. The aluminum slag source of the wastewater center of the aluminum processing enterprise is subdivided into: the mold-stewing waste liquid alkali slag accounts for 30 percent of the total slag, the alkaline etching liquid alkali slag accounts for 20 percent of the total slag, the oxidizing liquid acid slag accounts for 30 percent of the total slag, and the spraying acid waste slag accounts for 20 percent of the total slag.

The wastewater contains Al³⁺、Na⁺、NH₄ ⁺、Ni₂ ⁺、Sn²⁺、Cr⁶⁺Iso cation, SO₄ ^2-、F^-、NO^3-、NO₂ ^-、S^2-、Cl^-Anions, organic compounds such as organic phenols, surfactants, and acrylic resins. The acidic waste water and the alkaline waste water are usually mixed for post-treatment, while the chromium-containing waste water and the nickel-containing waste water must be treated separately. Acid and alkali water are all mixed together for treatment, the wastewater is acidic after being mixed, a large amount of caustic soda flakes, lime, PAC and PAM are required to be added, and a large amount of waste residues are generated.

The recycling rate of water in the current aluminum processing industry is less than 30%, and a large amount of waste residues are generated after wastewater treatment. On one hand, a large amount of useful resources such as metallic aluminum, acid, alkali and the like in the waste residue are not utilized, which causes huge resource waste, as shown in fig. 2, the source condition of aluminum-containing waste residue in a certain large aluminum material plant. The waste residue belongs to dangerous waste and has great environmental hazard. Zero discharge of waste water, zero output of waste residues and maximum resource utilization value are realized, and the method has great environmental benefit, social benefit and economic benefit.

(II) treatment and utilization status of waste residue in aluminum industry

1. Electrolytic casting aluminum ash treatment and utilization status

Many methods for recycling and resource utilization of aluminum ash are developed at home and abroad successively, and in recent years, patents on recycling of aluminum ash are on the rise, but most of the aluminum ash are in experimental research stage, and the technology is limited to the aspects of extracting metal aluminum under high temperature condition, preparing inorganic materials such as aluminum oxide, aluminum chloride and aluminum sulfate and steelmaking auxiliary materials, and the like, and has a certain distance from industrialization and large-scale production.

1.1 aluminum ash recovery

The existing methods for recovering aluminum ash can be divided into a heat treatment method and a cold treatment method, and only metal aluminum in the aluminum ash is recovered. A large-scale domestic regenerated aluminum plant adopts a tilting rotary kiln treatment method: aluminum ash and additive salts (usually a mixture of sodium chloride, potassium chloride and a small amount of calcium fluoride) are placed in a tilting rotary kiln to be heated and then metal aluminum is separated, but smoke is generated in the recovery process, the metal recovery rate is low, the residual aluminum content in the aluminum ash is high, and further recovery space is still left. Other methods include press recovery, plasma dissolution, electric separation, MRM, and ALUREC.

1.2 comprehensive utilization of aluminum ash

Because the components of the aluminum ash are basically consistent with those of bauxite, the products produced by the bauxite are subjected to experimental research by using the aluminum ash. Currently, there are three main routes in resource utilization of aluminum ash: (1) the recovered alumina is returned to electrolysis, and the recovered chloride is used as a fusion casting refining agent, but the main component in the aluminum ash is alpha-Al₂O₃The activity is poor, and more energy is consumed for ionizing the cell, so that the cell voltage is increased. (2) Acid method or alkali method for removing impurity, producing synthetic brown corundum, Sialon ceramic and refractory material, etc. inorganic material, producing polyaluminium chloride, aluminium sulfate and other water purifying material, and producing slag-forming desulfurizer for steel-making. (3) The production of building materials or road building materials, such as aluminate cement, calcium aluminate powder, ganged bricks, road building materials and the like, but the performance is influenced by the contained fluoride and chloride, and the added value of the product is low, so that the practical application is limited. The applications of the three aspects all have the defects of low product purity, low added value, secondary pollution of waste and the like. The waste after the aluminum ash is recycled still contains a large amount of soluble salts and fluorides, is dangerous waste and can be only buried or stacked, and the environmental hazard is not reduced.

Because the aluminum ash contains a certain amount of components such as chloride (NaCl, KCl and the like) and fluoride with high temperature resistance, corrosion resistance, toxicity and the like, the conventional method is difficult to realize the recycling of all components, the resource cost and the technical difficulty of the aluminum ash are increased, and the industrialization of the aluminum ash treatment is slowly progressed. In addition, the migration and transformation mechanism of harmful elements such as fluorine and heavy metals in the aluminum ash treatment process is not further discussed.

In order to realize zero waste of the aluminum ash resource, the resource utilization idea must be changed, various components in the aluminum ash are fully utilized, and harmless treatment and resource maximized utilization are carried out. The work is urgent, needs to be oriented clearly, guided in a standard way and cooperated in multiple ways, and strives to make a real-time breakthrough in the early days.

2. Extrusion surface treatment wastewater and waste residue treatment and utilization status

1. The recovery treatment of waste water and waste residue, comprehensive utilization comprises two aspects: firstly, water is recycled; and secondly, the resource of the waste residue is comprehensively utilized.

1.1, extruding die-stewing waste liquid and recovering alkaline etching liquid before oxidation treatment

The extrusion die-cooking waste liquid contains a large amount of sodium hydroxide and aluminum ions, and a lot of research reports and patents are provided in the aspect of die-cooking waste liquid recovery. The current method for treating the die-cooking waste liquid in the aluminum processing enterprises is as follows: the waste water from the die-stewing process and the waste acid generated in the oxidation process are neutralized and precipitated for post-treatment slag making, and the waste slag generated from the waste liquid from the die-stewing process accounts for about 30 percent of the total slag amount of enterprises. Enterprises do not recycle sodium hydroxide, aluminum ions and other useful resources in the die-cooking waste liquid, but increase the cost, and the treatment of waste water and waste residues becomes a heavy burden on environmental protection.

The recovery of the oxidation pretreatment alkaline etching solution generally adopts a crystallization method to recover sodium hydroxide, but the sodium hydroxide has the advantages of fine granularity, low purity and low economic value. In addition, the crystallization method keeps the aluminum ions at a low concentration (less than 30g/L), which is easy to cause defects of coarse crystals, coarse sand, over corrosion and the like of the section bar, and the aluminum consumption is too high. The crystallization method has high requirements on operation and process, can precipitate and scale due to poor management, and is time-consuming and labor-consuming. A small number of manufacturers put on online alkali recovery devices, and most of the devices are abandoned due to poor recovery effect and high cost. The alkaline etching bath solution added with the corrosion inhibitor and the complexing agent is not suitable for an alkaline recovery device, and the application of the technology is also limited.

1.2 recovery of alumina ions and sulfuric acid from the oxidized liquid

The aluminum ions in the aluminum alloy anodic oxidation solution directly influence the conductivity and the film quality of the bath solution, and the optimal control concentration is within the range of 3-10 g/L. The aluminum ions are accumulated and increased along with the increase of the production quantity, the quality of a film layer is poor, and the power consumption is increased, but the aluminum ion concentration in the actual production of an enterprise is generally controlled within the range of 15-20g/L in consideration of the medicament cost and the environmental protection pressure. After reaching the upper limit, the aluminum ion content must be reduced. The common practice for reducing aluminum ions is to discharge half of the bath solution and continue production after sulfuric acid is replenished. The method is simple, but has the following defects: firstly, sulfuric acid is lost, aluminum ions are wasted, and the consumption of the sulfuric acid reaches more than 60 kg/t; secondly, the waste acid treatment increases considerable cost; thirdly, a great amount of waste residue causes environmental harm.

Sulfuric acid reclaimers that employ the principle of diffusion dialysis have been widely used as a means of controlling aluminum ions. The sulfuric acid recovery machine is a stabilizing device for aluminum ions, and the aim of recovering sulfuric acid and removing aluminum ions is fulfilled by adopting a diffusion dialysis ion exchange membrane. In actual operation, the method has the defects of poor recovery effect, high energy consumption, low efficiency, no reduction of slag quantity and the like. In view of the above-mentioned poor utilization of the sulfuric acid reclaimer, most aluminum processing enterprises have gradually stopped the plant, restoring the traditional method of inverting half of the oxidation bath.

1.3 spray pretreatment wastewater recovery

The market share of powder spray coated aluminum alloy products has increased significantly in recent years, now accounting for over 60% of aluminum alloy surface treated products. The purpose of the spraying surface pretreatment is to generate a layer of compact conversion coating on the surface of the aluminum material and firmly bond the base material and the spraying layer together. In order to ensure the quality of the conversion film, the process control requirement is very strict, and the over-standard bath solution and rinsing water must be drained. The waste water is acidic and contains a large amount of hexavalent chromium, fluotitanic acid, fluozirconate and fluorinion. The treatment of a large amount of waste acid not only increases the enterprise cost, but also wastes resources, and has environmental hazard. The spraying pretreatment and wastewater treatment technology has no obvious progress, and a traditional method is still adopted to form a large amount of waste residues after neutralization, precipitation, filter pressing and dehydration. Waste residues belong to strictly controlled hazardous wastes and must be transferred to qualified third parties for standardized harmless treatment.

1.4 chromium-and nickel-containing waste water

Chromium and nickel belong to a class of pollutants, chromium-containing or nickel-containing wastewater must be separately treated, and chromium slag (HW21) and nickel slag (HW17) belong to dangerous wastes.

The recovery of hexavalent chromium ions is still a difficult problem, and the online recovery of chromium-containing medicaments cannot be realized. The current treatment method of the chromium-containing wastewater comprises the following steps: adding reducing agents such as sodium pyrosulfite or sodium bisulfite and the like to reduce hexavalent chromium into trivalent chromium with lower toxicity, then adding alkali and PAM to perform reaction precipitation, and dehydrating and filter-pressing sludge to obtain chromium slag. An exemplary process flow is shown in fig. 3.

The recovery of nickel ions is only limited to a coloring tank, and the nickel ions in the hole sealing wastewater are directly discharged due to low content. The recovery of nickel ions uses an RO recovery unit, which has the same principle as that of acid recovery, but has low efficiency and produces a large amount of concentrated water. The nickel-containing wastewater is treated by a precipitation method, sodium hydroxide and PAM are added, the pH is adjusted, nickel hydroxide precipitate is generated by reaction, and the nickel slag is obtained after sludge dehydration and filter pressing. An exemplary process flow is shown in fig. 4.

1.5 extrusion surface treatment wastewater and waste residue comprehensive treatment

Many aluminum section manufacturers actively explore and practice in many aspects in the aspects of water saving and waste water treatment, and obtain certain effect. At present, the waste water in the aluminum processing industry is still treated by adopting a neutralization regulation and coagulating sedimentation method, and the treatment process comprises the following steps: the acid-base waste water is neutralized, the pH is adjusted to be neutral, and cation Al3+ and the like form hydroxide precipitates. And (3) pumping the neutralized and precipitated wastewater into a coagulation tank, adding flocculating agents PAC and PAM, flocculating, then entering the precipitation tank, discharging or recycling clear liquid after reaching the standard, and performing filter pressing on the water-containing sludge by a filter press to form aluminum-containing waste residues. The water content of the waste residue is about 80 percent, and the quantity is very large. A typical waste residue treatment scheme is shown in figure 5.

To sum up, the traditional waste water and waste residue treatment mode has the following defects: firstly, the wastewater can reach the standard after being treated, but the reuse rate of reclaimed water is low; secondly, the wastewater treatment cost is high, and the consumption of manpower, medicament and power is increased; thirdly, a large amount of useful resources such as acid, alkali, metal aluminum, chemical agents and the like are wasted; fourthly, the waste residue belongs to dangerous waste, the disposal cost is high, and environmental protection tax needs to be paid.

2. Comprehensive utilization of waste water and waste residue in extrusion surface treatment

The comprehensive utilization comprises two aspects: firstly, water is recycled; and secondly, the resource of the waste residue is comprehensively utilized. The recycling status is not ideal, and the recycling rate of water is less than 30%, and the ways and methods for comprehensively utilizing the aluminum slag, the chromium slag and the nickel slag are limited.

2.1 comprehensive utilization of aluminum slag

The resource utilization research of the aluminum-containing waste residue has been carried out for many years, and a plurality of articles and patent technologies exist, and the technical path of resource utilization is basically the same as that of aluminum ash, and the resource utilization mainly comprises the following aspects: (1) directly recovering aluminum hydroxide or aluminum oxide; (2) synthesizing ceramics or refractory materials such as mullite, cordierite, ceramic frit, artificial resin marble and the like; (3) producing water purification materials such as calcium aluminate, polyaluminum chloride (iron), polyaluminum sulfate, and the like; (4) for example, Chinese patent CN 1350065A discloses a method for preparing ammonium aluminum sulfate, aluminum sulfate and aluminum hydroxide by using alkaline residue, and Chinese patent CN 101186282B discloses a method for preparing ammonium alum by reducing aluminum ions in a hard sulfuric acid oxidizing bath solution.

Besides the successful application of the technology for preparing the aluminum hydroxide by utilizing the acid sludge, the comprehensive utilization rate of the aluminum sludge is very low, mainly because the technology is immature, the added value of the product is low and the cost is high. Most of waste residues are paid and disposed by aluminum material factories, and the waste residues of a plurality of aluminum material factories are accumulated like a mountain at present, so that the blanched Chinese yam of the aluminum material factories is formed.

2.2 comprehensive utilization of chromium slag and nickel slag

The chromium slag is disclosed to be useful as a glass colorant and a crystallization accelerator, but the practical application is not described in detail. No public data of nickel slag resource utilization is found. The current method for the chromium slag and the nickel slag is to transfer to a third party organization for harmless burying treatment.

3. The extrusion surface treatment of waste water and waste residue has problems

Firstly, the water consumption is high, a mature water-saving technology is lacked, and the water reuse rate is low; secondly, the waste water is classified on line and cannot become a preposed program, so that the waste residue generation amount is large; thirdly, the comprehensive utilization effect of the waste residue is not large, and the waste residue treatment becomes the burden of enterprises and the environmental protection risk.

Currently, there are three outstanding contradictions and problems with waste residue treatment: firstly, the country manages the pollutant discharge license of the enterprise and controls the total pollutant discharge amount of the enterprise, and the actual waste water and waste residue amount of the enterprise is far larger than the allowable discharge amount; secondly, the waste residue must be legally transferred to a qualified third party for disposal, but the disposal capability is obviously insufficient, so that the huge amount of waste residue cannot be legally treated; thirdly, waste residues are treated according to dangerous waste specifications, the process is complex, the efficiency is low, and the cost is high.

In summary, the treatment of waste water and waste residue in the domestic aluminum processing industry at present is contradictory, the comprehensive treatment difficulty is high, the cost is high, the recovery rate is low, the resource waste is caused, and the environment pollution is serious. Therefore, for the aluminum processing industry, the method has wide prospect and huge environmental benefit, social benefit and economic benefit for research, development, popularization and application of wastewater zero discharge and resource comprehensive utilization technology.

(III) aluminum ash and aluminum slag reduction and recycling direction in aluminum industry

1. The principle followed is: the reduction control, the harmless treatment and the resource utilization can be actively developed only by combining three forces of government promotion, enterprise dominance and third party market allocation resources;

2. source control, namely classification interception, on-line conversion and resource utilization of each medicament tank, and reduction of the discharge amount of waste water and waste residue;

3. the environment-friendly surface treatment technology is popularized and applied. Aiming at the pollution problem of the oxidation line, the technology of additive-free alkaline etching, nickel-free fluorine-free hole sealing and the like is popularized and applied;

4. and the production and research combination is strengthened, the thought and the field of comprehensive utilization of waste residues are expanded, and the maximum comprehensive utilization value is realized.

Disclosure of Invention

The invention aims to overcome the defects, provides a system and a method for recovering a nickel-tin salt coloring agent and medium-temperature hole sealing agent in aluminum processing, realizes the resource recycling of toxic wastes by utilizing an online classified recovery and compatibility method, carefully selecting agent components and skillfully configuring the system, and realizes the recycling of solid dangerous waste resources by modifying the obtained tin hydroxide and basic nickel carbonate into a nickel-tin salt coloring agent.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a nickel tin salt coloring and medicament recovery system of medium temperature hole sealing in aluminum processing, includes including nickel tin containing waste water interception unit, nickel tin containing waste water collection unit, tin ion recovery unit and nickel ion recovery unit from upper reaches to low reaches in proper order, its characterized in that:

the nickel-tin containing wastewater interception unit comprises a 13# nickel-tin salt coloring tank, a 14# flowing rinsing tank, a 15# high-pressure atomizing spray tank, a 16# medium-temperature hole sealing tank, a 17# flowing rinsing tank and a 18# flowing rinsing tank which are sequentially arranged, wherein the 18# flowing rinsing tank is externally connected with tap water, the 14# flowing rinsing tank, the 15# high-pressure atomizing spray tank, the 17# flowing rinsing tank and the 18# flowing rinsing tank are reversely connected in series, and the 16# medium-temperature hole sealing tank is compatibly arranged for the 13# nickel-tin salt coloring tank;

the nickel-tin containing wastewater collecting unit comprises a nickel-tin containing wastewater collecting pool A and a nickel-tin containing wastewater collecting pool B, and a water outlet of the 14# flowing water washing tank is respectively provided with a pipeline connected with the nickel-tin containing wastewater collecting pool A and a pipeline connected with the nickel-tin containing wastewater collecting pool B;

the tin ion recovery unit comprises a 1# pump, a tin recovery tank, a 1# centrifuge, a tin secondary crystallization tank and a 2# pump which are sequentially arranged, wherein the 1# pump is used for pumping nickel-tin-containing wastewater of a nickel-tin-containing wastewater collecting pool A and a nickel-tin-containing wastewater collecting pool B into the tin recovery tank, and the tin recovery tank is used for pumping Sn in the nickel-tin-containing wastewater²⁺The No. 1 centrifuge is used for separating solid tin hydroxide and liquid nickel-tin-containing wastewater, and the tin secondary crystallization tank is used for separating Sn in the separated nickel-tin-containing wastewater²⁺The 2# pump is used for pumping the tin secondary crystal in the tin secondary crystallization tank into the tin recovery tank;

the nickel ion recovery unit comprises a nickel recovery tank, a 2# centrifugal machine, a nickel secondary crystallization tank and a 3# pump which are sequentially arranged, wherein the 2# pump is also used for pumping nickel-containing supernatant in the tin secondary crystallization tank into the nickel recovery tank, and the nickel recovery tank is used for pumping Ni in the nickel-containing supernatant²⁺The 2# centrifuge is used for separating solid basic nickel carbonate and liquid nickel-containing supernatant, and the nickel secondary crystallization tank is used for separating Ni in the separated nickel-containing supernatant²⁺The 3# pump is used for pumping the nickel secondary crystal in the nickel secondary crystallization tank into the nickel recovery tank and pumping the crystallized nickel-free supernatant into a subsequent wastewater treatment unit.

Preferably, in the nickel-tin containing wastewater interception unit, be equipped with the 1# valve on the pipeline of the external running water of the water inlet of 18# mobile wash bowl, be equipped with the 2# check valve on the pipeline that the delivery port of 18# mobile wash bowl and the water inlet of 17# mobile wash bowl are connected, be equipped with the 4# high-pressure pump between the water inlet of 15# high-pressure atomization spray bowl and the delivery port of 17# mobile wash bowl, be equipped with the 3# check valve on the pipeline that the delivery port of 17# mobile wash bowl and the water inlet of 4# high-pressure pump are connected, be equipped with the 5# pump between the delivery port of 15# high-pressure atomization spray bowl and the water inlet of 14# mobile wash bowl.

Preferably, in the nickel-tin containing wastewater collection unit, a water inlet of the nickel-tin containing wastewater collection tank a, a water inlet of the nickel-tin containing wastewater collection tank B and a water outlet of the 14# flowing water washing tank are connected through a three-way pipe, a 5# valve is arranged at one end of the three-way pipe connected with the 14# flowing water washing tank, a 6# valve is arranged at one end of the three-way pipe connected with the nickel-tin containing wastewater collection tank a, and a 7# valve is arranged at one end of the three-way pipe connected with the nickel-tin containing wastewater collection tank B;

the pipeline that the delivery port of nickeliferous tin waste water collecting pit A and the water inlet of 1# pump are connected is equipped with the 8# valve, the pipeline that the delivery port of nickeliferous tin waste water collecting pit B and the water inlet of 1# pump are connected is equipped with the 9# valve.

Preferably, in the tin ion recovery unit, a pipeline connecting a water outlet of the 1# pump and a water inlet of the tin recovery tank is provided with a 10# valve, a pipeline connecting a water outlet of the tin recovery tank and a water inlet of the 1# centrifuge is provided with a 11# valve, the 1# centrifuge is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the 1# centrifuge is connected with the water inlet of the tin secondary crystallization tank through a pipeline;

a first supernatant liquid output port, a second supernatant liquid output port and a third supernatant liquid output port are vertically arranged in the middle of the tin secondary crystallization tank, a first crystallization output port is arranged at the bottom of the tin secondary crystallization tank, a 12# valve is arranged on a pipeline connecting the first supernatant output port of the tin secondary crystallization tank and the water inlet of the 2# pump, a 13# valve is arranged on a pipeline connecting a second supernatant fluid outlet of the tin secondary crystallization tank and a water inlet of the 2# pump, a pipeline for connecting a third supernatant fluid output port of the tin secondary crystallization tank with a water inlet of the 2# pump is provided with a 14# valve, a 15# valve is arranged on a pipeline connecting a first crystallization output port of the tin secondary crystallization tank and a water inlet of the 2# pump, a pipeline for connecting the first water outlet of the 2# pump and the water inlet of the tin recovery tank is provided with a 16# valve, a 17# valve is arranged on a pipeline connecting a second water outlet of the 2# pump and a water inlet of the nickel recovery tank;

the inside of tin recovery jar is provided with # 1 electric agitator, the inside of tin secondary crystallization jar is provided with # 2 electric agitator.

Preferably, in the nickel ion recovery unit, a pipeline connecting a water outlet of the nickel recovery tank and a water inlet of the 2# centrifuge is provided with an 18# valve, the 2# centrifuge is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the 2# centrifuge is connected with the water inlet of the nickel secondary crystallization tank through the pipeline;

a fourth supernatant fluid output port, a fifth supernatant fluid output port and a sixth supernatant fluid output port are vertically arranged in the middle of the nickel secondary crystallization tank, a second crystallization output port is arranged at the bottom of the nickel secondary crystallization tank, a 19# valve is arranged on a pipeline connecting a fourth supernatant output port of the nickel secondary crystallization tank and a water inlet of the 3# pump, a pipeline for connecting the fifth supernatant fluid output port of the nickel secondary crystallization tank with the water inlet of the 3# pump is provided with a 20# valve, a 21# valve is arranged on a pipeline connecting a sixth supernatant fluid output port of the nickel secondary crystallization tank and a water inlet of the 3# pump, a 22# valve is arranged on a pipeline connecting a second crystallization output port of the nickel secondary crystallization tank and a water inlet of the 3# pump, a 23# valve is arranged on a pipeline connecting the first water outlet of the 3# pump and the water inlet of the nickel recovery tank, a 24# valve is arranged on a pipeline connecting a second water outlet of the 3# pump and a water inlet of the wastewater treatment unit;

the inside of nickel recovery jar is provided with 3# electric agitator, the inside of nickel secondary crystallization jar is provided with 4# electric agitator.

Preferably, the recovery method using the agent recovery system for nickel-tin salt coloration and medium-temperature hole sealing in aluminum processing comprises the following steps:

step one, opening the No. 1 valve, enabling tap water to enter the No. 18 flowing water washing tank, and then enabling the tap water to enter the No. 17 flowing water washing tank through the No. 2 one-way valve; starting the No. 4 high-pressure pump, and enabling water to flow through the No. 3 one-way valve and enter a No. 15 high-pressure atomization spraying groove; starting the 5# pump, and pumping the water in the 15# high-pressure atomization spraying tank into a 14# flowing water washing tank; opening the No. 5 valve, and discharging the water in the No. 14 flowing water washing tank through the No. 5 valve;

secondly, the aluminum alloy wrapped with the oxide film is firstly colored in the 13# nickel-tin salt coloring tank and trickles for 30 s; then the mixture enters the No. 14 flowing water washing tank to be washed for 60s and trickles for 30 s; then the mixture enters the No. 15 high-pressure atomization spraying groove to be cleaned for 60s and trickles for 30 s; then the mixture enters a 16# medium temperature hole sealing groove for hole sealing for 15min and trickles for 30 s; then the mixture enters a No. 17 flowing water washing tank for washing for 60s and trickles for 30s, and finally enters a No. 18 flowing water washing tank for washing for 60s and trickles for 30 s;

step three, opening the No. 6 valve, and enabling the nickel-tin-containing wastewater flowing out of the No. 14 flowing water washing tank to enter the nickel-tin-containing wastewater collecting tank A; or opening a 7# valve, and enabling the nickel-tin-containing wastewater flowing out of the 14# flowing rinsing bath to enter a nickel-tin-containing wastewater collecting pool B;

opening the 8# valve or the 9# valve, opening the 10# valve, closing the 11# valve, opening the 1# pump, and pumping the nickel-tin-containing wastewater in the nickel-tin-containing wastewater collecting pool A or the nickel-tin-containing wastewater collecting pool B into the tin recovery tank; starting the No. 1 electric stirrer, slowly adding sodium carbonate into the tin recovery tank, and adding Sn in the nickel-tin-containing wastewater²⁺Converting into solid tin hydroxide; starting the No. 1 centrifugal machine, opening the No. 11 valve, performing solid-liquid separation, recovering solid tin hydroxide, and flowing liquid nickel-tin-containing wastewater into the tin secondary crystallization tank for crystallization treatment;

after crystallization, opening the 12# valve, the 13# valve or the 14# valve, closing the 15# valve and the 16# valve, starting the 2# pump, and pumping the nickel-containing supernatant in the tin secondary crystallization tank into the nickel recovery tank; then, closing the 12# valve, the 13# valve, the 14# valve and the 17# valve, opening the 15# valve and the 16# valve, opening the 2# pump and the 2# electric stirrer, pumping the tin secondary crystal in the tin secondary crystallization tank into the tin recovery tank, and performing secondary tin recovery;

step five, starting the No. 3 electric stirrer, slowly adding sodium carbonate into the nickel recovery tank, and adding Ni in the nickel-containing supernatant²⁺Converting the nickel carbonate into solid basic nickel carbonate; opening the 2# centrifugal machine, opening the 18# valve, performing solid-liquid separation, recovering solid basic nickel carbonate, and flowing liquid nickel-containing supernatant into the tin secondary crystallization tank for crystallization treatment;

after crystallization, opening the 19# valve, the 20# valve or the 21# valve, opening the 24# valve, closing the 22# valve and the 23# valve, starting the 3# pump, and pumping the nickel-free supernatant in the nickel secondary crystallization tank to a subsequent wastewater treatment unit for neutralization treatment; then, the 19# valve, the 20# valve, the 21# valve and the 24# valve are closed, the 22# valve and the 23# valve are opened, the 3# pump and the 4# electric stirrer are started, and the nickel secondary crystals in the nickel secondary crystallization tank are pumped into the nickel recovery tank to carry out secondary recovery of nickel.

Preferably, the method further comprises the following steps:

step six, rinsing the stannic hydroxide obtained in the step four, adding pure water for wetting, slowly adding sulfuric acid (98%), reacting to generate a stannous sulfate solution under the condition of excessive sulfuric acid, and stopping the reaction when the pH value of the generated stannous sulfate solution is 0.8;

step seven, rinsing the basic nickel carbonate obtained in the step five, adding pure water for wetting, slowly adding sulfuric acid (98%), reacting to generate a nickel sulfite solution under the condition of excessive sulfuric acid, and setting the pH value of the generated nickel sulfite solution to be 0.8 as a reaction endpoint;

and step eight, titrating the concentration of a stannous sulfate solution and the concentration of a nickelous sulfate solution and adding tartaric acid according to the nickel-tin salt coloring control index of the 13# nickel-tin salt coloring tank to form the nickel-tin salt coloring agent which can be directly added to the 13# nickel-tin salt coloring tank.

Preferably, the nickel tin salt coloring control indexes of the 13# nickel tin salt coloring tank are as follows: 10g/L stannous sulfate, 25g/L nickel sulfate, 18g/L sulfuric acid and 8g/L tartaric acid, the pH value is 0.8-1.2, the temperature is 20-25 ℃, the treatment time is 30s-15min, and the voltage is 14-16V.

Preferably, in the fourth step, while slowly adding sodium carbonate into the tin recovery tank, detecting the pH value of the solution in the tin recovery tank, when the pH value of the solution in the tin recovery tank reaches 4.8, stopping adding the sodium carbonate, and continuing stirring for 30 min; and in the fifth step, the pH value of the solution in the nickel recovery tank is detected while sodium carbonate is slowly added into the nickel recovery tank, when the pH value of the solution in the nickel recovery tank reaches 9.0, the addition of the sodium carbonate is stopped, and the stirring is continued for 30 min.

Preferably, the medium-temperature hole sealing indexes of the 16# medium-temperature hole sealing groove are 5g/L of nickel acetate, 0.5g/L of triethanolamine and 0.5g/L of isobutanol, the pH value is 5.5-6.5, the temperature is 50-60 ℃, and the treatment time is 10-25 min; the thickness of the oxide film on the surface of the aluminum alloy is 15 microns.

The chemical recovery system for nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing is used for the nickel-tin-containing toxic waste residues generated by oxidation coloring hole sealing in aluminum processing, and ensures that the recovered nickel-tin-containing products are recycled to a 13# nickel-tin salt coloring tank by utilizing an online classification recovery and compatibility method, selecting chemical components and skillfully configuring the system, so that the recycling cyclic utilization of toxic wastes is realized. The chemical recovery system for coloring nickel-tin salt and sealing holes at medium temperature in aluminum processing can treat about 1600 ten thousand tons of nickel-tin containing wastewater generated by oxidizing, coloring and sealing holes in aluminum processing on line, convert about 4 ten thousand tons of toxic waste residue containing nickel-tin and generate about 10 ten thousand tons of nickel-tin salt colorant.

Drawings

The drawings are further illustrative of the invention and the content of the drawings does not constitute any limitation of the invention.

FIG. 1 is a report of the detection of the components of a conventional aluminum ash;

FIG. 2 is a pie chart of an aluminum-containing waste slag source of a large aluminum plant;

FIG. 3 is a flow chart of the conventional chromium-containing wastewater treatment;

FIG. 4 is a flow chart of the prior nickel-containing wastewater treatment;

FIG. 5 is a flow chart of the conventional waste water and residue treatment;

FIG. 6 is a diagram of a conventional oxidation coloring hole sealing process and slot placement according to one embodiment of the present invention;

FIG. 7 is a diagram of a chemical recovery system for nickel-tin salt coloration and medium-temperature hole sealing in aluminum processing according to one embodiment of the present invention.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

The embodiment is realized according to the following theoretical basis, a nickel tin salt colorant recovery system, a recovery method and quantitative and qualitative analysis:

theoretical basis for producing coloring agent by coloring nickel-tin salt and recycling hole sealing cleaning water

The traditional oxidation coloring hole sealing process flow and the slot position arrangement are shown in figure 6, each working slot is provided with two flowing water washing slots, 18 slot positions are needed for oxidation treatment, wherein a 13# nickel tin salt coloring slot and a 16# medium temperature hole sealing slot contain nickel and tin salt, and the subsequent water washing slots bring nickel-tin-containing wastewater into a wastewater treatment center to generate toxic waste residues containing nickel and tin. The functions of the 13# nickel-tin salt coloring tank, the 14# flowing rinsing tank, the 15# high-pressure atomizing spray tank, the 16# medium-temperature sealed hole tank, the 17# flowing rinsing tank and the 18# flowing rinsing tank related by the invention are as follows:

the purpose of 13# nickel tin salt coloring tank is to color the oxide film and improve the decorativeness of the aluminum alloy. Generally, a single nickel salt, a single tin salt or a mixed nickel-tin salt is used for coloring, and an additive such as a phenol, an organic acid or boric acid is added to stabilize the coloring liquid. The coloring control indexes of the mono-nickel salt are as follows:

150g/L of nickel sulfate, 50g/L of boric acid, 3.5-4.5 of pH value, 20-25 ℃ of temperature and 30s-15min (1) of treatment time;

the mono-nickel salt coloring bath solution is very stable, but requires high purity of chemical agents and weak pollution resistance, and requires that a No. 12 flowing water washing tank and a No. 11 flowing water washing tank before coloring are washed by flowing pure water; in addition, with increasing environmental requirements, the heavy metal nickel may be included in the list of banned uses.

The tin salt coloring bath solution is unstable and easy to get turbid, but the concentration of the bath is low, about 15g/L, the pollution resistance is strong, and the color system is rich. In view of the tendency that nickel salts may be banned from use, there is an urgent need to develop new coloring stabilizers to completely stabilize tin salts.

The electrolytic coloring of the nickel-tin mixed salt can be carried out by coloring with bronze, imitation stainless steel color, champagne color and pure black color. The electrolytic coloring liquid of the nickel-tin mixed salt has good coloring dispersibility, and the formed colored film has uniform color, elegance and luxury, good sun resistance, corrosion resistance and wear resistance, and the coloring liquid has strong anti-fouling capability. The control parameters suitable for large-scale production are as follows: 10g/L stannous sulfate, 25g/L nickel sulfate, 18g/L sulfuric acid and 8g/L tartaric acid, wherein the pH value is 0.8-1.2, the temperature is 20-25 ℃, the treatment time is 30s-15min, and the voltage is 14-16V (2);

the coloring by the nickel-tin mixed salt electrolyte not only has low cost and long service time, but also can obtain the color and quality which cannot be obtained by the single nickel salt or tin salt, thereby being deeply favored by the majority of aluminum manufacturers. However, like the single tin salt coloration, stannous ions in nickel-tin mixed salt electrolytic coloring systems are extremely unstable. Even in an acidic solution having a pH of 1.0, oxygen electrolytically released from the air or from hydroxyl ions is easily oxidized to high-valent tin ions, and further hydrolyzed to form white stannic acid precipitates, which slightly affect the quality of the colored film and, if so, completely deactivate the coloring liquid. Therefore, the control is mainly focused on ensuring the stability of stannous ions and controlling the color tone.

The nickel-tin salt is colored, the tin salt is the main, and the coloring speed and uniformity are improved due to competitive reduction when the nickel-tin salt and the tin salt coexist. The nickel tin salt is less in dosage and more stable than the single tin salt, and the color tone of the nickel tin salt is yellow and transparent red. The nickel salt is preferably 20-25g/L, too high color is dark, but when the color is pure black, the color is preferably raised to 45 g/L. In general, 6-8g/L of stannous salt is suitable. The lower limit is taken in summer, the upper limit is used in winter, and the pure black color is required to be increased to 10-12 g/L. The additive plays the roles of improving the uniformity, preventing the stannous from hydrolysis and the like, but the complexing ability of the current coloring tank is not enough, and the stannous can be oxidized and hydrolyzed as usual, so tartaric acid is added to complex stannous ions. The sulfuric acid has double functions of preventing hydrolysis of tin salt and raising electric conductivity, and free sulfuric acid is controlled in 15-20g/L preferably. Sulfuric acid is less glossy, the coloring speed and gloss of sulfuric acid are reduced too much, and the coloring speed is increased to 25g/L only when the coloring speed is too high, so that hydroxide is prevented from being generated on the surface. Some nickel-tin mixed salt coloring solutions are added with boric acid, which has a buffering effect in pores, is beneficial to nickel electrodeposition, improves uniformity and improves color impression, preferably 20-25g/L, and has dark color when being too high.

Sn²⁺The ions are easily oxidized by all oxidants and then hydrolyzed into colloidal Sn (OH)₂And Sn (OH)₄Either settled on the bottom of the tank or suspended in the solution. During the coloring process, Sn is precipitated in several cases²⁺Oxidation and hydrolysis:

1. oxidation by agitation of the bath

In order to make the temperature and the concentration of the bath solution uniform, the coloring bath solution should be stirred during production, although a circulating pump is adopted for avoiding direct stirring by air, the opportunity that the bath solution is contacted with the air is increased, and the reaction that the bivalent tin is easily oxidized into the tetravalent tin can occur during the contact with the air:

SnSO₄+H₂SO₄+O＝H₂O+Sn(SO₄)₂↓ (3)；

2. oxidation and hydrolysis occurring at electrode reaction

When the electrode is at the anode half-cycle, the reaction of losing electrons from hydroxyl to generate oxygen occurs:

4OH^--4e＝2O+2H₂O (4)；

in the coloring process, Sn²⁺The oxygen generated in the reaction of the formula (4) is easily reacted with the oxygen in the electrode reaction to oxidize the oxygen, and a turbid substance is generated according to the formula (3). In addition, the aluminum alloy is used as a cathode, and the hydrogen evolution reaction can cause the local pH value to rise, thereby promoting the Sn in the tank²⁺And Sn⁴ ⁺Ion hydrolysis reaction:

Sn²⁺+2OH^-＝Sn(OH)₂↓ (5)；

Sn⁴⁺+4OH^-＝Sn(OH)₄↓ (6)；

due to the presence of the above reaction and Sn²⁺The longer the using period of the bath solution, the more serious the suspension turbidity. Good additives should have a certain combination of ability to protect against Sn²⁺The hydrolysis of ion precipitation also has the functions of accelerating ionization and improving dispersion capability. Otherwise, the coordination of complexing and ionization dynamic equilibrium is not good in the coloring process, Sn²⁺Poor conditions for ion deposition in the pores affect coloring efficiency and coloring hue.

The surface can be uniformly colored by adding additives such as magnesium sulfate, aluminum sulfate, ammonium thiosulfate and the like into the coloring liquid. The electrolytic coloring liquid mainly containing tin salt has the main problems of preventing or slowing down the oxidation of bivalent tin, improving the stability of the electrolytic coloring liquid and prolonging the service life of the electrolytic coloring liquid. Besides additives such as tartaric acid, phenol, sulfuric acid, boric acid, etc., oxidation inhibitors are added, for example: ascorbic acid, biphenyl, hydroquinone, and the like. Wherein the sulfuric acid can acidify the solution and reduce the pH value; the boric acid has buffering and complexing functions, and the tartaric acid, the citric acid and the ammonium tartrate can complex stannous ions and also have a buffering function on the pH value. The addition of thiourea or hydrazine sulfate can reduce tetravalent tin ions. An agent such as ferrous ion is added instead of the divalent tin ion being oxidized, that is, when the divalent tin ion and the ferrous ion coexist, the oxidation reaction of the ferrous ion occurs before the oxidation reaction of the divalent tin ion to the tetravalent tin ion, thereby controlling the transition of the divalent tin ion to the tetravalent tin ion. The additives added in the method are substances with buffering effect, complexing effect and antioxidation effect and can complex Sn²⁺Ions, or capable of being preferentially oxidized by dissolved oxygen in solution to prevent Sn²⁺The ions are oxidized to Sn by air⁴⁺Further, Sn (OH) is generated₄White precipitates affect the coloration.

By comprehensively considering the factors, the formula design of the coloring stabilizer must meet four requirements: 1. the uniformity of the coloring is improved; 2. preventing white spots and cracks from being generated; 3. stabilizing the stannous salt; 4. the conductivity of the electrolyte is improved.

In order to obtain the color uniformity of the stainless steel champagne color series aluminum profile, the technological parameters of the anodic oxidation tank need to be strictly controlled, the thickness of the oxidation film is required to be consistent, the smaller the deviation is, the better the deviation is, and the better the deviation is, the control is 12 μm. The anodizing time is determined according to the process parameter conditions of the anodizing bath. Furthermore, the coloration parameters must also be controlled:

(1) time and temperature

Experiments prove that the time of electrolytic coloring is accurate to the time calculated by seconds, and is determined according to the conditions of various process parameters of the electrolytic coloring tank. The difference of one second of coloring time has obvious influence on the color of champagne electrophoretic painting aluminum profiles, the coloring time is prolonged, the Sn content in the oxide film is increased, and the color of the oxide film is gradually deepened. The content of Sn in the oxide film linearly increases along with the time, and the relation is as follows:

W＝4.4+2.5t(1≤t≤5)。

the bath temperature of the electrolytic coloring bath can be regulated to be 20-25 ℃. When the temperature of the coloring bath solution rises, the conductivity of the coloring solution increases, and Sn²⁺The precipitation reaction speed is accelerated, and the coloring speed is accelerated. In addition, the increase of the coloring liquid temperature is not favorable for Sn²⁺The stability of (2). Sn (tin)²⁺The oxidation reaction speed of (2) increases as the temperature of the coloring liquid increases. Therefore, in order to ensure the color consistency of champagne electrophoretic painting aluminum profiles, the temperature of the coloring bath solution is well controlled, and the smaller the fluctuation range, the better.

(2) pH value

When the pH value of the coloring bath solution is about 1.0, the coloring speed is basically unchanged. When the pH is more than 1.1, the coloring speed is high and is difficult to control; if the pH is too small, the corrosion resistance of the colored film is adversely affected. Thus, a pH of 0.8 to 1.0 is an important factor in the formation of a uniform color of champagne-colored aluminium profiles.

(3) Voltage of

The voltage of the coloring liquid is controlled to be 14-16V (stainless steel color is 10-13V), and the current density is 0.6-0.8A/dm²And keeping the zero voltage for 1-1.5 min. Boost control is important, boosting the voltage by 1V approximately every 3 s. The coloring speed is greatly affected when the voltage is less than 14V or more than 16V.

(4) Washing with water

The anode is not accurately placed in the first washing tank after being oxidized, and the anode is colored when the anode is placed in the second washing tank for not more than 2min, so that the adverse effect of sulfuric acid in the washing tank on an oxidation film is avoided. The pH value of the second rinsing bath is required to be more than or equal to 3. After the coloring timing is finished, the cloth is lifted to be transferred to a next rinsing bath immediately and then is subjected to color matching, the cloth cannot stay in the coloring bath, and the lifting transfer time in the air is strictly controlled. The pH value of the colored rinsing bath is required to be more than or equal to 3. During the water washing process, the coloring metal salt in the pores of the film is easily attacked by acidic substances in water, resulting in discoloration.

From the coloring effect, the color of the nickel-tin mixed salt is more beautiful than the color of the nickel salt or the tin salt which is singly used, and the heat resistance and the light resistance of the color meet the requirements. When the stannous sulfate is less than 2/L, the coloring speed is relatively slow, and when the coloring speed is increased to more than 5/L, the coloring speed is obviously accelerated; the concentration range of nickel sulfate is wide.

The 14# flowing water washing tank and the 15# high-pressure atomizing spraying tank are used for cleaning residual coloring agent brought out by the coloring tank and protecting the hole sealing tank. Similarly, tap water enters from a No. 15 high-pressure atomization spraying tank and exits from a No. 14 flowing water washing tank and is reversely connected in series, the water consumption is 2.0 to 3.0 tons per ton of material, the water consumption is too large, and the discharged waste water contains tin and nickel, so that the environmental protection treatment pressure is increased.

The purpose of the No. 16 medium-temperature hole sealing groove is to seal the micropores of the oxide film and ensure the corrosion resistance of the oxide film. The well-sealing tank can also be replaced by an electrophoresis tank. The hole sealing method is divided into high-temperature, medium-temperature and normal-temperature hole sealing according to the working temperature. The high-temperature hole sealing is to treat the aluminum material in pure water at 95-100 ℃, has good hole sealing quality, but has high energy consumption, large water evaporation capacity, easy ash hanging and easy impurity ion poisoning, and needs to frequently replace bath solution; the medium-temperature hole sealing is generally carried out by adopting a method of adding an additive into nickel acetate, the treatment is carried out at 55-65 ℃, the hole sealing speed is high, less ash is attached, the film is not cracked, but the hole sealing contains nickel and tin, and the environment is not protected; the normal temperature hole sealing adopts a method of adding additive into nickel fluoride, the hole sealing is processed at 25-35 ℃, the hole sealing speed is fast, less ash is attached, the energy consumption is low, and the use is convenient. But the film is easy to crack, and the fluorine and the nickel are not beneficial to environmental protection. At present, the medium-temperature hole sealing is taken as a main treatment method in China. The medium-temperature hole sealing control indexes are as follows:

5g/L nickel acetate, 0.5g/L triethanolamine, 0.5g/L isobutanol, 5.5-6.5 pH value, 50-60 deg.C and 10-25min (7);

the 17# flowing water washing tank and the 18# flowing water washing tank are arranged for cleaning the hole sealing tank to bring out a residual agent containing nickel, and the aluminum product is protected from being corroded after leaving a factory. Similarly, tap water enters from the No. 18 flowing water washing tank and exits from the No. 17 flowing water washing tank and is reversely connected in series, the water consumption is 2.0-3.0 tons per ton of wood, the water consumption is too large, and the discharged nickel-containing wastewater increases the environmental protection treatment pressure.

After the aluminum material is processed by 18 slots, the aluminum material can be packaged and delivered out of a factory to finish the anodic oxidation treatment.

The defects of the oxidation line are exposed after the application for hundreds of years. Particularly, today emphasizing the production of clean civilization, the oxidation line 13# nickel-tin salt coloring tank, 14# flowing water washing tank, 15# high-pressure atomizing spray tank, 16# medium-temperature hole sealing tank, 17# flowing water washing tank and 18# flowing water washing tank need to be greatly improved in the following aspects:

1. the traditional treatment of mixing and reprocessing the cleaning water needs to be changed into classification treatment, so that the treatment cost is greatly reduced. The design concept of the traditional process is unreasonable, the 13# nickel-tin salt coloring tank and the 16# medium-temperature hole sealing tank are nickel-tin-containing tank liquid, aluminum materials are colored and hole-sealed and then directly enter four flowing rinsing tanks, namely a 14# flowing rinsing tank, a 15# high-pressure atomizing spraying tank, a 17# flowing rinsing tank and a 18# flowing rinsing tank, the nickel-tin-containing wastewater is brought into the center of the wastewater to pollute the cleaning water of other processes of the whole oxidation line; after mixing, the nickel-tin containing wastewater is treated and discharged after reaching the standard, the difficulty is conceivable, and the cost is remarkable. The method needs to be improved urgently, can be treated separately by online classification, replaces the traditional mixed treatment method, and reduces the environmental protection cost;

2. the traditional cleaning water needs to be changed into two inlets and two outlets, namely one inlet and one outlet, so that the cleaning water is greatly reduced, the treatment cost is saved, and a solid foundation is laid for online classification treatment and equipment miniaturization. The rinsing tanks behind the two functional tanks are independent respectively, and the water consumption is too large due to the two water inlets and the two water outlets. 4 rinsing baths, the total water consumption is 4-6 tons/ton of wood. In addition to the cost of water, the disposal and discharge of such waste water requires additional costs. The cleaning mode is urgently needed to be improved, a washing water tank connecting mode of reversely connecting washing water in series and one inlet and one outlet can be used for replacing the traditional two sets of cleaning modes of mutually independent washing and two inlets and two outlets, half of water is saved, and the environmental protection cost is reduced;

3. the traditional concept of passively treating the waste water and the waste residues needs to be abandoned, the waste water and the waste residues containing nickel and tin are treated from the resource perspective, hazardous wastes are changed into valuable chemical resources, the treatment cost is greatly reduced, and the maximization of the value utilization of the chemical products containing nickel and tin is realized. The traditional process design concept is unreasonable, nickel-tin-containing wastewater is brought into the center of the wastewater, and cleaning water of other procedures of the whole oxidation line is polluted; the wastewater center neutralizes, precipitates and presses the wastewater to obtain solid waste residue containing nickel and tin; the mass nickel-tin-containing waste residues are clearly specified as hazardous wastes by the national ministry of environmental protection; to treat the nickel-tin-containing hazardous wastes, enterprises and society need to pay high environmental protection cost and waste precious nickel resources. The extensive production mode is urgently needed to be improved, special equipment can be configured, nickel and tin containing products are actively recycled on line, waste is changed into valuable, and the resource utilization of hazardous waste is realized.

In modern aluminum processing enterprises, nickel-tin-containing waste water and waste residues generated by coloring and sealing holes with nickel-tin salt are in urgent need of treatment, while the traditional method for treating the waste water and waste residues after mixing with large amount of cleaning water is too simple, so that a large amount of nickel-tin-containing waste residues are generated and treated, and the society pays expensive environmental protection cost for the waste residues.

The system and the method for recovering the nickel-tin salt coloring and medium-temperature hole sealing agent in the aluminum processing are a new process produced after unprecedented system research and development are carried out on the nickel-tin salt coloring hole sealing treatment process which has large waste water and waste residue amount and huge environmental protection pressure of the existing aluminum processing enterprises after the production confusion of the aluminum processing enterprises are fully known and researched for many years:

1) and the nickel-tin composite salt is colored, washed and separately collected for treatment.

According to the formula (2), the nickel-tin salt coloring bath solution is not stable and easy to decompose, tartaric acid is required to be added for complexing stannous ions, and sulfuric acid is added for reducing the pH value to 0.8-1.2. After the aluminum material is colored for 30s-15min, hanging trickles flow for 30s, enter a 14# flowing water washing tank, are washed for 1min, hanging trickles flow for 30s, enter a 15# high-pressure atomizing spraying tank, are washed for 1min, hanging trickles flow for 30s, and enter a 16# medium-temperature hole sealing tank, so that the coloring and water washing process is completed. When cleaning is carried out after coloring, nickel sulfate, stannous sulfate, tartaric acid and sulfuric acid contained in coloring liquid are brought into a No. 14 flowing water washing tank and a No. 15 high-pressure atomizing and spraying tank to pollute flowing cleaning water; the pH value of the 13# nickel tin salt coloring tank is 0.8-1.2, the pH value of the water inlet of the 15# tank is 6.0-7.0, so that the pH value of the 14# flowing water washing tank is 1.5-3.5, stannous sulfate in the interval is unstable and begins to decompose to generate stannic hydroxide; the pH value of the No. 15 tank is 3.5-6.0, and stannous sulfate in the region is more unstable and is completely decomposed into stannic hydroxide;

2) and hole sealing water washing is independently recovered.

And (3) according to the formula (7), after hole sealing is carried out on the aluminum material for 10-25min, hanging trickling flows for 30s, the aluminum material enters a No. 17 flowing water washing tank, cleaning is carried out for 1min, hanging trickling flows for 30s, the aluminum material enters an No. 18 flowing water washing tank, cleaning is carried out for 1min, hanging trickling flows for 30s, and the aluminum material enters an air drying area, so that the hole sealing and water washing processes are completed. When cleaning is carried out after hole sealing, nickel acetate, triethanolamine and isobutanol contained in the hole sealing liquid are brought into the No. 17 flowing water washing tank and the No. 18 flowing water washing tank to pollute flowing cleaning water; the pH value of the 16# medium temperature hole sealing tank is 5.5-6.5, the pH value of the water inlet of the 18# flowing water washing tank is 6.0-7.0, so that the pH values of the 17# flowing water washing tank and the 18# flowing water washing tank are 5.5-7.0, and nickel acetate, triethanolamine and isobutanol in the interval are stable and do not decompose and can be independently collected and treated.

3) And the coloring water washing and the hole sealing water washing are connected in series in an opposite phase manner, mixed and collected.

When the aluminum material is colored and cleaned, stannous sulfate, nickel sulfate, tartaric acid and sulfuric acid contained in the coloring liquid are brought into a 14# flowing water washing tank and a 15# high-pressure atomization spraying tank; the pH value of the No. 14 flowing water washing tank is 1.5-3.5, stannous sulfate in the interval is unstable and begins to decompose to generate stannic hydroxide; the pH value of the No. 15 high-pressure atomization spray tank is between 3.5 and 6.0, and stannous sulfate in the interval is more unstable and is completely decomposed into stannic hydroxide; when the aluminum material is cleaned after hole sealing, nickel acetate, triethanolamine and isobutanol contained in the hole sealing liquid are brought into a No. 17 flowing water washing tank and a No. 18 flowing water washing tank; the pH values of the No. 17 flowing water washing tank and the No. 18 flowing water washing tank are between 5.5 and 7.0, and the nickel acetate, the triethanolamine and the isobutanol in the interval are stable and do not decompose. And closing a tap water inlet of the No. 15 high-pressure atomizing and spraying tank, and reversely connecting the cleaning water at a water outlet of the No. 17 flowing water washing tank in series to a water inlet of the No. 15 high-pressure atomizing and spraying tank to realize reverse large series connection of the cleaning water entering from the No. 18 flowing water washing tank, passing through the No. 17 flowing water washing tank, the No. 15 high-pressure atomizing and spraying tank and the No. 14 flowing water washing tank and finally flowing out from the water outlet of the No. 14 flowing water washing tank. In such a series connection mode, nickel acetate, triethanolamine and isobutanol contained in the No. 17 flowing water washing tank and the No. 18 flowing water washing tank are brought into the No. 14 flowing water washing tank and the No. 15 high-pressure atomization spraying tank, and two aspects need to be considered: firstly, whether a 14# flowing rinsing bath and a 15# high-pressure atomization spraying bath are turbid or not enables the aluminum material to be coated with ash; and whether the hole sealing capability of the 16# medium-temperature hole sealing groove is influenced or not.

A. And (3) analyzing the stability of the 14# flowing water washing tank and the 15# high-pressure atomization spraying tank.

The pH value of the No. 14 flowing water washing tank is 1.5-3.5, stannous sulfate in the interval is unstable and begins to decompose to generate stannic hydroxide; the pH value of the No. 15 high-pressure atomization spray tank is between 3.5 and 6.0, and stannous sulfate in the interval is more unstable and is completely decomposed into stannic hydroxide; the two rinsing baths are turbid, the aluminum material is easy to be dusted, the cleaning mode needs to be improved, the 15# high-pressure atomization spraying bath is used, the water is efficiently saved for cleaning, the cleaning water is greatly reduced, then the spraying water is pumped into the 14# flowing rinsing bath from the 15# high-pressure atomization spraying bath, and then the spraying water flows out from the water outlet of the 14# flowing rinsing bath. As the spraying water is used for saving water, the pH value of the No. 14 flowing rinsing bath is lower than 2.0, stannous sulfate is temporarily undetermined, the surface of the aluminum material is clean, and the risk of ash hanging is avoided;

B. and analyzing the influence of the 15# high-pressure atomization spray tank on the hole sealing tank.

The cleaning water at the water outlet of the 17# flowing water washing tank is pumped into the 15# high-pressure atomizing spraying tank by using the 4# high-pressure pump to clean the aluminum material, and trace hole sealing liquid can be brought into the 16# medium temperature hole sealing tank along with the aluminum material, and the hole sealing liquid is an inherent component of the 16# medium temperature hole sealing tank, so that the hole sealing capability of the 16# medium temperature hole sealing tank can not be influenced absolutely according to a self-compatibility principle, and the reversed-phase series water washing is feasible.

Second, chemical recovery system and method for nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing

Combining the practical continuous production of coloring and hole sealing, the factors of medicament recovery, water interception and the like, the number of slots and the like, a medicament recovery system for coloring nickel-tin salt and sealing holes at medium temperature in aluminum processing is shown in figure 7,

the device comprises a nickel-tin-containing wastewater interception unit, a nickel-tin-containing wastewater collection unit, a tin ion recovery unit and a nickel ion recovery unit from upstream to downstream in sequence;

Contain nickel tin waste water and hold back in the unit, be equipped with the 1# valve on the pipeline of the external running water of the water inlet of the rinsing bath that flows of 18#, be equipped with the 2# check valve on the pipeline that the delivery port of the rinsing bath that flows of 18# and the water inlet of the rinsing bath that flows of 17# are connected, be equipped with the 4# high-pressure pump between the water inlet of 15# high pressure atomization spray bath and the delivery port of the rinsing bath that flows of 17#, be equipped with the 3# check valve on the pipeline that the delivery port of the rinsing bath that flows of 17# and the water inlet of the 4# high-pressure pump are connected, be equipped with the 5# pump between the delivery port of 15# high pressure atomization spray.

In the nickel-tin containing wastewater collection unit, a water inlet of the nickel-tin containing wastewater collection pool A, a water inlet of the nickel-tin containing wastewater collection pool B and a water outlet of the No. 14 flowing water washing tank are connected through a three-way pipe, a No. 5 valve is arranged at one end of the three-way pipe connected with the No. 14 flowing water washing tank, a No. 6 valve is arranged at one end of the three-way pipe connected with the nickel-tin containing wastewater collection pool A, and a No. 7 valve is arranged at one end of the three-way pipe connected with the nickel-tin containing wastewater collection pool B;

In the tin ion recovery unit, a pipeline connecting a water outlet of the No. 1 pump and a water inlet of the tin recovery tank is provided with a No. 10 valve, a pipeline connecting a water outlet of the tin recovery tank and a water inlet of the No. 1 centrifugal machine is provided with a No. 11 valve, the No. 1 centrifugal machine is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the No. 1 centrifugal machine is connected with the water inlet of the tin secondary crystallization tank through a pipeline;

In the nickel ion recovery unit, a pipeline connecting a water outlet of the nickel recovery tank and a water inlet of a 2# centrifugal machine is provided with a 18# valve, the 2# centrifugal machine is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the 2# centrifugal machine is connected with the water inlet of the nickel secondary crystallization tank through the pipeline;

The nickel-tin-containing wastewater interception unit is used for intercepting the chemicals brought out by the 13# nickel-tin salt coloring tank and the 16# medium-temperature hole sealing tank, and keeping the chemicals in the 14# flowing water washing tank, the 15# high-pressure atomization spraying tank, the 17# flowing water washing tank and the 18# flowing water washing tank, so that the trouble of treating massive wastewater after mixing with other water is avoided, and the environmental protection cost for treating the nickel-tin-containing wastewater is greatly reduced; the nickel-tin-containing wastewater interception unit adopts a coloring hole sealing water reverse series connection mode, and reversely connects the water consumption of the 16# medium-temperature hole sealing tank and the 13# nickel-tin salt coloring tank in series, so that half of the water consumption is reduced, and a solid foundation is laid for online separate treatment of nickel-tin-containing wastewater and equipment miniaturization.

The nickel-tin-containing wastewater collection unit is responsible for separately collecting nickel-tin-containing wastewater flowing out of a water outlet of the 14# flowing water washing tank, and avoiding mixing with other water so as to be separately treated.

The tin ion recovery unit recovers Sn in the nickel-tin-containing wastewater²⁺The reaction is converted into solid tin hydroxide to realize the primary recovery of tin, and the reaction liquid can be sodium carbonate; the nickel ion recovery unit recovers Ni in the nickel-tin-containing wastewater²⁺The reaction is converted into solid basic nickel carbonate to realize the primary recovery of nickel, and the reaction liquid can be sodium carbonate. The tin secondary crystallization tank is used for carrying out tin secondary crystallization, and a crystallized tin secondary crystal is pumped into the tin recovery tank to realize secondary recovery of tin; and the nickel secondary crystallization tank is used for carrying out secondary crystallization on nickel, and the crystallized secondary nickel crystal is pumped into the nickel recovery tank to realize secondary recovery of nickel. And the obtained tin hydroxide and basic nickel carbonate are reformed into the nickel-tin salt colorant, so that the recycling of solid hazardous waste resources is realized.

The recovery method of the agent recovery system using nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing comprises the following steps:

step one, opening the No. 1 valve, enabling tap water to enter the No. 18 flowing water washing tank, and then enabling the tap water to enter the No. 17 flowing water washing tank through the No. 2 one-way valve; starting the No. 4 high-pressure pump, and enabling water to flow through the No. 3 one-way valve and enter a No. 15 high-pressure atomization spraying groove; starting the 5# pump, and pumping the water in the 15# high-pressure atomization spraying tank into a 14# flowing water washing tank; opening the 5# valve, enabling water in the 14# flowing water washing tank to flow out through the 5# valve, and enabling only one piece of washing water to flow in series in a reverse direction to finish the whole set of water washing;

secondly, the aluminum alloy wrapped with the oxide film is firstly colored in the 13# nickel-tin salt coloring tank and trickles for 30 s; then the mixture enters the No. 14 flowing water washing tank to be washed for 60s and trickles for 30 s; then the mixture enters the No. 15 high-pressure atomization spraying groove to be cleaned for 60s and trickles for 30 s; then the mixture enters a 16# medium temperature hole sealing groove for hole sealing for 15min and trickles for 30 s; then the wastewater enters a No. 17 flowing water washing tank for cleaning for 60s and trickles for 30s, and finally enters a No. 18 flowing water washing tank for cleaning for 60s and trickles for 30s, so that the nickel-tin-containing wastewater interception unit operation is completed;

step three, opening the No. 6 valve, and enabling the nickel-tin-containing wastewater flowing out of the No. 14 flowing water washing tank to enter the nickel-tin-containing wastewater collecting tank A; or opening a 7# valve, and allowing the nickel-tin-containing wastewater flowing out of the 14# flowing water washing tank to enter a nickel-tin-containing wastewater collecting pool B to complete the operation of a nickel-tin-containing wastewater collecting unit;

after crystallization, opening the 12# valve, the 13# valve or the 14# valve, closing the 15# valve and the 16# valve, starting the 2# pump, and pumping the nickel-containing supernatant in the tin secondary crystallization tank into the nickel recovery tank; then, closing the 12# valve, the 13# valve, the 14# valve and the 17# valve, opening the 15# valve and the 16# valve, opening the 2# pump and the 2# electric stirrer, pumping the tin secondary crystal in the tin secondary crystallization tank into the tin recovery tank, performing secondary recovery of tin, and finishing the operation of a tin ion recovery unit;

after crystallization, opening the 19# valve, the 20# valve or the 21# valve, opening the 24# valve, closing the 22# valve and the 23# valve, starting the 3# pump, and pumping the nickel-free supernatant in the nickel secondary crystallization tank to a subsequent wastewater treatment unit for neutralization treatment; then, closing the 19# valve, the 20# valve, the 21# valve and the 24# valve, opening the 22# valve and the 23# valve, opening the 3# pump and the 4# electric stirrer, pumping the nickel secondary crystal in the nickel secondary crystallization tank into the nickel recovery tank, performing secondary recovery of nickel, and finishing the operation of a nickel ion recovery unit;

step six, rinsing the stannic hydroxide obtained in the step four, adding pure water for wetting, slowly adding sulfuric acid (98%), reacting to generate a stannous sulfate solution under the condition of excessive sulfuric acid, and stopping the reaction when the pH value of the generated stannous sulfate solution is 0.8; detecting and marking the concentration of stannous sulfate;

step seven, rinsing the basic nickel carbonate obtained in the step five, adding pure water for wetting, slowly adding sulfuric acid (98%), reacting to generate a nickel sulfite solution under the condition of excessive sulfuric acid, and setting the pH value of the generated nickel sulfite solution to be 0.8 as a reaction endpoint; detecting the concentration of the identified nickel sulfate;

and step eight, titrating the concentration of the stannous sulfate solution and the concentration of the nickelous sulfate solution and adding tartaric acid according to the nickel-tin salt coloring control index of the 13# nickel-tin salt coloring tank to form the nickel-tin salt coloring agent which can be directly added to the 13# nickel-tin salt coloring tank.

The method for recovering the nickel-tin salt colorant in the aluminum processing is used for the nickel-tin-containing toxic waste residues generated by oxidation coloring hole sealing in the aluminum processing, and the method for recovering and compatible with the nickel-tin-containing toxic waste residues by online classification, carefully selecting medicament components and skillfully configuring a system ensures that the recovered nickel-tin-containing products are recycled to a 13# nickel-tin salt coloring tank, thereby realizing the recycling of the toxic waste. And the obtained tin hydroxide and basic nickel carbonate are reformed into the nickel-tin salt colorant, so that the recycling of solid hazardous waste resources is realized.

The coloring control indexes of the nickel-tin salt of the 13# nickel-tin salt coloring tank are as follows: 10g/L stannous sulfate, 25g/L nickel sulfate, 18g/L sulfuric acid and 8g/L tartaric acid, the pH value is 0.8-1.2, the temperature is 20-25 ℃, the treatment time is 30s-15min, and the voltage is 14-16V.

In the fourth step, while slowly adding sodium carbonate into the tin recovery tank, detecting the pH value of the solution in the tin recovery tank, stopping adding the sodium carbonate when the pH value of the solution in the tin recovery tank reaches 4.8, and continuing stirring for 30 min;

and in the fifth step, the pH value of the solution in the nickel recovery tank is detected while sodium carbonate is slowly added into the nickel recovery tank, when the pH value of the solution in the nickel recovery tank reaches 9.0, the addition of the sodium carbonate is stopped, and the stirring is continued for 30 min.

The medium-temperature hole sealing indexes of the 16# medium-temperature hole sealing groove are 5g/L of nickel acetate, 0.5g/L of triethanolamine and 0.5g/L of isobutanol, the pH value is 5.5-6.5, the temperature is 50-60 ℃, and the treatment time is 10-25 min;

the thickness of the oxide film on the surface of the aluminum alloy is 15 microns.

Third, quantitative and qualitative analysis of coloring agent produced by nickel-tin salt coloring and hole sealing cleaning water recovery

After reverse-phase series water washing, the water outlet of the 14# flowing water washing tank contains nickel sulfate, stannous sulfate, nickel acetate, sulfuric acid, triethanolamine and isobutanol, the concentration of the medicament at the water outlet of the 14# flowing water washing tank is about 2 percent of that of the 13# nickel tin salt coloring tank and the 16# medium-temperature hole sealing tank according to the formulas (2) and (7) and the consumption of 2.5 tons of washing water per ton of aluminum material, namely 0.5g/L of nickel sulfate, 0.2g/L of stannous sulfate, 0.16g/L of tartaric acid, 0.36g/L of sulfuric acid, 0.1g/L of nickel acetate, 0.01g/L of triethanolamine and 0.01g/L of isobutanol. The treatment mode of each chemical component is as follows:

1. crystallizing and separating out stannous ion contained in stannous sulfate. Controlling a 13# nickel-tin salt coloring tank and a 16# medium-temperature hole sealing tank according to (2) and (7), reversely connecting in series to wash to produce a coloring hole sealing material, taking 1L of washing water at a water outlet of a 14# flowing water washing tank, and detecting the concentration of a medicament as follows:

stannous sulfate 0.22g/L, nickel sulfate 0.53g/L, tartaric acid 0.17g/L, nickel acetate 0.12g/L, triethanolamine 0.01g/L, isobutanol 0.01g/L, and the pH value is 1.86 (8);

sodium carbonate was added slowly and the pH was gradually increased with the following changes:

when the pH value is lower than 2.0, the liquid in the tank is clear, no precipitate exists and no precipitate exists due to the complexation of tartaric acid;

at a pH between 2.0 and 3.0, the bath started to be cloudy and a small amount of white precipitate stannous hydroxide appeared:

Sn²⁺+2OH^-＝Sn(OH)₂↓ (9)；

when the pH is between 3.0 and 4.0, the bath solution is turbid, and the white precipitate stannous hydroxide is increased;

when the pH is between 4.0 and 4.5, the bath solution is turbid, and the white precipitate stannous hydroxide continues to increase;

when the pH value is between 4.5 and 5.0, the bath solution is turbid, and the white precipitate stannous hydroxide is not increased any more. And (4) carrying out solid-liquid separation, rinsing and drying to obtain industrial yellowish crystalline powder stannous hydroxide meeting the national standard requirements.

2. Nickel ions contained in the nickel sulfate and the nickel acetate are crystallized and separated out.

According to the formula (9), carrying out solid-liquid separation, and detecting the concentration of the liquid medicament as follows:

0.52g/L of nickel sulfate, 0.11g/L of nickel acetate, 0.15g/L of tartaric acid, 0.01g/L of triethanolamine and 0.01g/L of isobutanol, and the pH value is 4.85 (10);

when the pH value is lower than 7.0, the liquid in the tank is clear, no precipitate exists and no precipitate exists due to the complexation of tartaric acid;

at a pH between 7.0 and 7.5, the bath started to be turbid, with a small amount of white precipitate of basic nickel carbonate:

3Ni²⁺+4OH^-+CO₃ ^2-+4H₂O＝NiCO₃.2Ni(OH)₂.4H₂O↓ (11)；

when the pH value is between 7.5 and 8.0, the bath solution is turbid, and white precipitate basic nickel carbonate is increased;

when the pH value is between 8.0 and 8.5, the bath solution is turbid, and the white precipitate of basic nickel carbonate continues to increase;

when the pH value is between 8.5 and 9.0, the bath solution is turbid, and white precipitates of the basic nickel carbonate are not increased any more.

3. Tartaric acid, triethanolamine and isobutanol do not react and remain in the liquid. According to the formula (11), with the addition of sodium carbonate, the pH is continuously raised, Ni²⁺Continuously react to generate NiCO₃、Ni(OH)₂、NiCO₃-2Ni(OH)₂-4H₂O, but tartaric acid, triethanolamine and isobutanol do not decompose, precipitate and remain in the liquid under the condition that the pH value does not exceed 9.

4. And (4) solid-liquid separation, namely separating tartaric acid, triethanolamine and isobutanol along with the liquid, and recovering solid basic nickel carbonate. According to the formula (11), the reaction product is subjected to solid-liquid separation. Tartaric acid, triethanolamine and isobutanol flow out along with the liquid to obtain solid basic nickel carbonate; and rinsing and drying to obtain the industrial grade basic nickel carbonate product meeting the national standard requirements.

5. According to the principle of medicament compatibility, the nickel-tin salt colorant is regenerated, and the recycling of solid hazardous waste is realized.

1) And producing the stannous sulfate solution. Weighing 100g of stannous hydroxide product obtained after rinsing and drying (drying only in the process of laboratory measurement and rinsing cleanly in the process of mass production without drying and saving production cost) and a proper amount of tin powder, adding 100g of pure water for wetting, slowly adding sulfuric acid (98 percent) and reacting as follows:

Sn(OH)₂+H₂SO₄＝SnSO₄+2H₂O；

the part of tetravalent tin which has been produced according to the reaction formulae (3) to (6) is reduced with tin powder:

Sn+Sn(OH)₄+2H₂SO₄＝2SnSO₄+4H₂O (12)；

taking excessive sulfuric acid, and detecting that the pH value of the stannous sulfate solution is 0.8, namely the reaction end point; detecting the concentration of stannous sulfate for later use;

2) and producing the nickel sulfate solution. Weighing 100g of basic nickel carbonate product obtained after rinsing and drying (drying only in the metering process of a laboratory, and rinsing cleanly in the large-scale production process, drying is not needed, and the production cost is saved), adding 100g of pure water for wetting, slowly adding sulfuric acid (98%), and reacting as follows:

NiCO₃.2Ni(OH)₂.4H₂O+3H₂SO₄＝3NiSO₄+9H₂O+CO₂↑ (13)；

taking excessive sulfuric acid, and detecting that the pH value of the nickel sulfate solution is 0.8, namely the reaction end point; detecting the concentration of nickel sulfate for later use;

3) and preparing the nickel-tin salt coloring liquid. Taking the stannous sulfate solution produced in the formula (12) and the nickel sulfate solution produced in the formula (13), and controlling the indexes of the nickel-tin salt coloring tank according to the formula (2): 10g/L stannous sulfate, 25g/L nickel sulfate, 18g/L sulfuric acid and 8g/L tartaric acid, the pH value is 0.8-1.2, the temperature is 20-25 ℃, the treatment time is 30s-15min, and the voltage is 14-16V.

The transformation method comprises the following steps:

nickel sulfate concentration/stannous sulfate concentration 25/10(g/L)

25/8(g/L) (14) nickel sulfate concentration/tartaric acid concentration;

firstly, obtaining stannous hydroxide according to the formula (9), and producing basic nickel carbonate according to the formula (11); then stannous sulfate is produced according to the formula (12), and nickel sulfate is produced according to the formula (13); finally, preparing the nickel-tin salt coloring liquid according to the formula (14). As the chemical agent of the 16# medium-temperature sealed hole tank is basically compatible with the 13# nickel-tin salt coloring tank, the nickel-tin salt coloring agent produced according to the formula (14) can be completely recycled to the 13# nickel-tin salt coloring tank.

Fourth, the experimental result of the production of nickel-tin salt colorant by the coloring of nickel-tin salt and the recycling of hole sealing cleaning water

Experiments

1 and 2 the coloring control index of nickel tin salt provided by the formula (2) were examined for the coloring power of the nickel tin salt colorant produced by the formula (14), respectively.

Experiment 1, effect of stannous sulfate concentration (actually colorant concentration) on tintability. Taking stannous sulfate with pH value of 1.0, temperature of 25 ℃ and concentration of 4, 6, 8, 10, 12 and 14 g/L; the aluminum material was observed for appearance color with an oxide film thickness of 15 μm and a coloring time of 4 minutes, and the results are shown in Table 1:

TABLE 1

Experiment 2, effect of coloring time on coloring color. Taking 10g/L stannous sulfate (25 g/L nickel sulfate and 8g/L tartaric acid) according to the formula (14), keeping the temperature at 25 ℃ and the pH value at 1.0; the thickness of the oxide film was taken to be 15 μm, and the coloring time was taken to be 6, 8, 10, 12, 14, and 16 minutes, and the results are shown in Table 2:

TABLE 2

Fifth, analysis of experimental results of producing nickel-tin salt colorant by coloring nickel-tin salt and recycling hole sealing cleaning water

According to the equations (8) to (14) and experiments 1 to 2 and the results of the measurements, the following analyses can be made:

1. according to the formula (8), by utilizing the principle that hole sealing washing is compatible with a 16# medium-temperature hole sealing tank, hole sealing water can be reversely connected in series to coloring water by utilizing a high-pressure atomization spraying washing method, two sets of washing are combined into one, half of water is saved, and nickel-tin-containing wastewater is intercepted and recovered at a water outlet of a 14# flowing washing tank;

according to the formula (9), the intercepted wastewater containing nickel and tin can be independently treated on line, industrial-grade stannous hydroxide is recovered, the solid hazardous waste containing nickel and tin is converted into high-value chemical raw materials, and the resource utilization of the solid hazardous waste is realized;

according to the formula (11), the intercepted wastewater containing nickel and tin can be independently treated on line, the industrial-grade basic nickel carbonate is recovered, the solid hazardous waste containing nickel and tin is converted into high-value chemical raw materials, and the resource utilization of the solid hazardous waste is realized;

according to the formula (12), the recovered stannous hydroxide can be further treated to produce a stannous sulfate solution, and the nickel-tin-containing solid hazardous waste is converted into a high-value chemical raw material, so that the resource utilization of the solid hazardous waste is realized;

according to the formula (13), the recovered basic nickel carbonate can be further treated to produce a nickel sulfate solution, so that the nickel-tin-containing solid hazardous waste is converted into a high-value chemical raw material, and the resource utilization of the solid hazardous waste is realized;

according to the formula (14), the converted stannous sulfate and nickel sulfate solution can be prepared into nickel-tin salt coloring solution according to the formula (2), and the nickel-tin salt coloring solution is recycled to the coloring tank, so that the resource recycling is realized;

from the results of

experiments

1 and 2, it is found that the nickel tin salt colorant prepared according to the formula (14) can completely satisfy the coloring requirement of the 13# nickel tin salt coloring tank within the control index range specified by the formula (2).

Continuously producing the colored hole sealing aluminum material according to the formula shown in FIG. 7, and continuously adding the coloring liquid recycled and manufactured in the embodiment into a 13# nickel-tin salt coloring tank according to the formula (2) control index; taking the coloring liquid, wherein the pH value of the coloring liquid is 1.0, the temperature is 25 ℃, and the stannous sulfate is 6-10 g/L; the thickness of the oxide film was taken to be 15 μm and the coloring time was taken to be 10 minutes, and the results are shown in the following Table 3:

TABLE 3

The system and the method for recovering the nickel-tin salt coloring and medium-temperature hole sealing agent in the aluminum processing have the following beneficial effects:

1. the nickel-tin containing wastewater interception unit is arranged for the first time and is responsible for intercepting medicaments brought out by the 13# nickel-tin salt coloring tank and the 16# medium-temperature hole sealing tank. According to the figure 7, when the colored hole sealing aluminum material is produced, the water washing tank intercepts the nickel-tin-containing wastewater and independently treats the nickel-tin-containing wastewater, so that the trouble of treating the massive wastewater after mixing with other water is avoided, and the environmental protection cost for treating the nickel-tin-containing wastewater is greatly reduced;

2. the method adopts a coloring hole sealing water reverse series connection mode in the nickel-tin-containing wastewater interception system for the first time. According to the graph shown in FIG. 6, when the colored hole sealing aluminum material is produced in the traditional mode, two sets of cleaning water are independent, the water consumption per ton of material is more than 4 tons, and the water consumption per industry is 1600 ten thousand tons; according to the figure 7, the hole sealing water and the coloring water are reversely connected in series for the first time, half of the water is reduced, and a solid foundation is laid for online independent treatment of nickel-tin-containing wastewater, stannous stabilization and equipment miniaturization;

3. the nickel-tin-containing wastewater collection unit is arranged on line for the first time and is responsible for separately collecting nickel-tin-containing wastewater flowing out of a water outlet of the No. 14 flowing water washing tank, and the nickel-tin-containing wastewater is prevented from being mixed with other water so as to be separately treated;

4. firstly, a tin ion recovery unit is arranged on line and is responsible for pumping the wastewater containing the nickel-tin wastewater collection pool into a tin recovery tank to recover Sn²⁺The stannous hydroxide is generated through reaction, and solid-liquid separation is realized; pumping the supernatant in the tin secondary crystallization tank into a nickel recovery tank, pumping the secondary crystal at the bottom of the tin secondary crystallization tank into the tin recovery tank again, and performing secondary recovery;

5. the nickel ion recovery unit is arranged on line for the first time and is responsible for recovering Ni²⁺Basic nickel carbonate is generated through reaction, and solid-liquid separation is realized; pumping the supernatant in the nickel secondary crystallization tank into a wastewater treatment center for neutralization treatment, pumping the secondary crystal at the bottom of the nickel secondary crystallization tank into a nickel recovery tank again for secondary recovery;

6. the recovered stannous hydroxide is further treated for the first time to produce a stannous sulfate solution, and the nickel-tin-containing solid hazardous waste is converted into a high-value chemical raw material, so that the resource utilization of the solid hazardous waste is realized;

7. the recovered basic nickel carbonate is further treated for the first time to produce a nickel sulfate solution, and the solid hazardous waste containing nickel and tin is converted into a high-value chemical raw material, so that the resource utilization of the solid hazardous waste is realized;

8. firstly, the converted stannous sulfate, nickel sulfate solution and coloring solution are required to be prepared into nickel tin salt coloring solution which is recycled to the coloring tank, so that the resource recycling is realized.

The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.

Claims

1. The utility model provides a nickel tin salt coloring and medicament recovery system of medium temperature hole sealing in aluminum processing, includes including nickel tin containing waste water interception unit, nickel tin containing waste water collection unit, tin ion recovery unit and nickel ion recovery unit from upper reaches to low reaches in proper order, its characterized in that:

the nickel ion recovery unit comprises a nickel recovery tank, a 2# centrifugal machine, a nickel secondary crystallization tank and a 3# pump which are sequentially arranged, wherein the 2# pump is also usedPumping the nickel-containing supernatant in the tin secondary crystallization tank into the nickel recovery tank, wherein the nickel recovery tank is used for pumping Ni in the nickel-containing supernatant²⁺The 2# centrifuge is used for separating solid basic nickel carbonate and liquid nickel-containing supernatant, and the nickel secondary crystallization tank is used for separating Ni in the separated nickel-containing supernatant²⁺The 3# pump is used for pumping the nickel secondary crystal in the nickel secondary crystallization tank into the nickel recovery tank and pumping the crystallized nickel-free supernatant into a subsequent wastewater treatment unit;

in the nickel-tin-containing wastewater interception unit, a 1# valve is arranged on a pipeline externally connected with tap water at a water inlet of the 18# flowing rinsing bath, a 2# check valve is arranged on a pipeline connecting a water outlet of the 18# flowing rinsing bath and a water inlet of the 17# flowing rinsing bath, a 4# high-pressure pump is arranged between the water inlet of the 15# high-pressure atomization spraying bath and the water outlet of the 17# flowing rinsing bath, a 3# check valve is arranged on a pipeline connecting a water outlet of the 17# flowing rinsing bath and a water inlet of the 4# high-pressure pump, and a 5# pump is arranged between the water outlet of the 15# high-pressure atomization spraying bath and the water inlet of the 14# flowing rinsing bath;

a pipeline for connecting the water outlet of the nickel-tin-containing wastewater collecting tank A with the water inlet of the pump No. 1 is provided with a valve No. 8, and a pipeline for connecting the water outlet of the nickel-tin-containing wastewater collecting tank B with the water inlet of the pump No. 1 is provided with a valve No. 9;

the coloring control indexes of the nickel-tin salt of the 13# nickel-tin salt coloring tank are as follows: 10g/L stannous sulfate, 25g/L nickel sulfate, 18g/L sulfuric acid and 8g/L tartaric acid, wherein the pH value is 0.8-1.2, the temperature is 20-25 ℃, the treatment time is 30s-15min, and the voltage is 14-16V;

the medium-temperature hole sealing indexes of the 16# medium-temperature hole sealing groove are 5g/L of nickel acetate, 0.5g/L of triethanolamine and 0.5g/L of isobutanol, the pH value is 5.5-6.5, the temperature is 50-60 ℃, and the treatment time is 10-25 min.

2. The agent recovery system for nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing according to claim 1, wherein:

3. The agent recovery system for nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing according to claim 2, wherein:

4. The recovery method using the agent recovery system for nickel-tin salt coloration and medium-temperature hole sealing in aluminum processing according to claim 3, characterized in that:

after crystallization, opening the 19# valve, the 20# valve or the 21# valve, opening the 24# valve, closing the 22# valve and the 23# valve, starting the 3# pump, and pumping the nickel-free supernatant in the nickel secondary crystallization tank to a subsequent wastewater treatment unit for neutralization treatment; then, closing the 19# valve, the 20# valve, the 21# valve and the 24# valve, opening the 22# valve and the 23# valve, opening the 3# pump and the 4# electric stirrer, pumping the nickel secondary crystal in the nickel secondary crystallization tank into the nickel recovery tank, and performing secondary recovery of nickel;

step six, rinsing the stannic hydroxide obtained in the step four, adding pure water for wetting, slowly adding 98% sulfuric acid, reacting to generate a stannous sulfate solution under the condition of excessive sulfuric acid, and stopping the reaction when the pH value of the generated stannous sulfate solution is 0.8;

step seven, rinsing the basic nickel carbonate obtained in the step five, adding pure water for wetting, slowly adding 98% sulfuric acid, reacting to generate a nickel sulfite solution under the condition of excessive sulfuric acid, and setting the pH value of the generated nickel sulfite solution to be 0.8 as a reaction terminal point;

step eight, titrating the concentration of a stannous sulfate solution and the concentration of a nickelous sulfate solution and adding tartaric acid according to the nickel-tin salt coloring control index of the 13# nickel-tin salt coloring tank to form a nickel-tin salt coloring agent which can be directly added to the 13# nickel-tin salt coloring tank;

5. The recovery method of the agent recovery system for nickel-tin salt coloring and medium-temperature hole sealing in aluminum processing according to claim 4, wherein: