CN108191107B - Recovery system and method for single nickel salt coloring and medium temperature hole sealing agent in aluminum processing - Google Patents

Abstract

A recovery system and a recovery method for a mono-nickel salt coloring and medium-temperature hole sealing agent in aluminum processing are disclosed, the system comprises a nickel-containing wastewater interception unit, a nickel-containing wastewater collection unit and a basic nickel carbonate recovery unit, wherein an 18# flowing water washing tank in the nickel-containing wastewater interception unit is externally connected with tap water, a 14# flowing water washing tank, a 15# flowing water washing tank, a 17# flowing water washing tank and an 18# flowing water washing tank are reversely connected in series, and a 13# mono-nickel salt coloring tank is compatibly arranged for a 16# medium-temperature hole sealing tank; the nickel-containing wastewater collecting unit comprises a nickel-containing wastewater collecting pool A and a nickel-containing wastewater collecting pool B, and a water outlet of the 14# flowing rinsing bath is provided with a pipeline connected with the nickel-containing wastewater collecting pool A and a pipeline connected with the nickel-containing wastewater collecting pool B; the basic nickel carbonate recovery unit comprises a No. 1 pump, a recovery tank, a centrifuge, a secondary crystallization tank and a No. 2 pump; the method can collect nickel-containing wastewater in an online classified manner, recover the basic nickel carbonate of the nickel-containing product on the basis of compatibility of medicaments, and convert the basic nickel carbonate into the intermediate-temperature hole sealing agent, thereby realizing the recycling and cyclic utilization of toxic wastes.

Description

Recovery system and method for single nickel salt coloring and medium temperature hole sealing agent in aluminum processing

Technical Field

The invention relates to the technical field of aluminum processing, in particular to a system and a method for recovering a single nickel salt coloring 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. 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 the aluminum ash 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. Along with the development of economy, the accumulation amount of the waste aluminum ash is greatly increased year by year, and if an economical, effective and harmless method is not found for treatment, the serious threat to the environment is more and more highlighted. 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. Even if the treated aluminum ash still contains a large amount of harmful substances, the aluminum ash can be only stockpiled or buried in a yard, so that the method has great environmental hazard and simultaneously a manufacturer bears great illegal risks. 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 discharged waste liquid contains a large amount of aluminum ions and sodium hydroxide, and the potential economic value is very high. The waste liquid of the die-stewing is generally treated by adopting a mode of treating waste by waste, namely neutralizing waste acid generated in an oxidation process, the waste residue generated by the treatment mode is very large, and the waste residue of the die-stewing can account for about 30 percent of the total residue 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 produced in the steps of anodic oxidation and electrophoretic painting are divided into 20 percent of the total residue by the alkaline waste water and waste residue produced in the alkaline etching solution; 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 that the caustic sludge of the mold-stewing waste liquid accounts for 30 percent of the total slag amount, the caustic etching liquid caustic sludge accounts for 20 percent of the total slag amount, the acid slag of the oxidizing liquid accounts for 30 percent of the total slag amount, and the spraying acid slag accounts for 20 percent of the total slag amount.

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. In recent years, the proportion of the oxidation electrophoresis material is reduced, but most aluminum material factories still have more acidic wastewater than alkaline wastewater, 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 latest version of the national records of dangerous wastes, which was applied from 8.1.2016, has recorded the records of acidic and alkaline waste water and waste residues in the records of HW34 and HW 35. According to the stipulation of the environmental protection tax Law of the people's republic of China, which is executed from 1 month and 1 day in 2018, an enterprise must pay 1000 yuan/ton of wastewater treatment sludge environmental protection tax.

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. At present, the situation forces enterprises to change the development to the direction of energy conservation, emission reduction and resource recycling, but the enterprises lack a mature and reliable technology. 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 mostly adopts a tilting rotary kiln treatment method, namely 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. The manual ash frying method in a small workshop is also widely adopted, and the method is open-type operation and generates a large amount of dust and smoke. 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. The resource utilization of the aluminum ash mainly comprises three routes of (1) recycling aluminum oxide for electrolysis and recycling chloride salt for use as a casting refining agent, but the main component of 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.

Under the conditions of resource shortage and increasingly serious environmental pollution, the development of the aluminum processing industry faces huge pressure on resources and environment, energy conservation, emission reduction and resource recycling, and the method is a development direction and a unique outlet in the future. 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, and the comprehensive utilization comprises two aspects, namely, the 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 exist in the aspect of die-cooking waste liquid recovery, such as a Crystalfix alkali recovery system in Italy, but the practical application is not many due to the complex flow and low comprehensive benefit. The common method for treating the waste liquid of the die in the aluminum processing enterprises is that the waste liquid of the die is neutralized and precipitated with the waste acid generated in the oxidation process, and then the waste slag generated by the waste liquid of the die is treated to prepare slag, wherein the waste slag accounts for about 30 percent of the total slag of the 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 when being not managed well, can only stop production and clean manually at the moment, 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. 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 chromium-containing wastewater is treated by 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 for reaction and precipitation, and dewatering 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 adopts an RO recovery device, the principle is the same as that of acid recovery, and the device is used by part of manufacturers, but the efficiency is low, and a large amount of concentrated water is generated, so that the effect is not ideal. 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 steps of mutually neutralizing acid-base waste water, regulating the pH value to be neutral, and forming hydroxide sediment by cation Al3 & lt + & gt and the like. 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.

In conclusion, the traditional waste water and waste residue treatment mode has the following defects that firstly, the waste water can reach the standard after being treated and is discharged, 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 of the recycling of water; 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 has a plurality of articles and patent technologies, the technical path of resource utilization is basically the same as that of aluminum ash, and the method mainly comprises the following aspects of (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) chemical products such as aluminum hydroxide, ammonium alum and the like are prepared by reaction, for example, Chinese patent CN 1350065A discloses a method for preparing aluminum ammonium sulfate, aluminum sulfate and aluminum hydroxide by using alkaline residue, Chinese patent CN 101186282B discloses a method for reducing aluminum ions and preparing ammonium alum by using hard sulfuric acid oxidation tank liquor, and Chinese patent CN 1319302C discloses a method for preparing aluminum hydroxide by using fluorine-containing acid residue, and the patent technology is practically applied in several factories, obtains excellent economic benefit and solves the problem of treatment of acid residue.

Except for the successful application of the technology for preparing the aluminum hydroxide by utilizing the acid sludge, most other methods are not applied in a large scale, the comprehensive utilization rate of the aluminum slag is very low, and the main reasons are that 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.

At present, three outstanding contradictions and problems exist in waste residue treatment, namely, the state carries out the management of the enterprise pollutant discharge license and controls the total pollutant discharge amount of an enterprise, and the actual waste water and waste residue amount of the enterprise is far more 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 of reduction control, harmless treatment and resource utilization is followed, and positive progress can be achieved only by integration of government promotion, enterprise dominance and third party market allocation of 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 provide a recovery system of a single nickel salt coloring and medium temperature hole sealing agent in aluminum processing, which utilizes an online classification recovery and compatibility method, carefully selects the components of the agent and skillfully configures the system to ensure that a recovered nickel-containing product is recycled to a hole sealing groove.

The invention also aims to provide a method for recovering the single nickel salt coloring and medium-temperature hole sealing agent in the aluminum processing, which is a brand new process design, collects nickel-containing wastewater in an online classified manner, recovers the basic nickel carbonate of a nickel-containing product on the basis of compatibility of the agent, converts the basic nickel carbonate into the medium-temperature hole sealing agent, and achieves the purpose of recycling toxic wastes.

The invention adopts the following technical scheme:

the recovery system of the single nickel salt coloring and medium temperature hole sealing agent in the aluminum processing sequentially comprises a nickel-containing wastewater interception unit, a nickel-containing wastewater collection unit and an alkali nickel carbonate recovery unit from upstream to downstream; the nickel-containing wastewater interception unit comprises a 13# single nickel salt coloring tank, a 14# flowing water washing tank, a 15# flowing water washing tank, a 16# medium temperature hole sealing tank, a 17# flowing water washing tank and a 18# flowing water washing tank which are sequentially arranged; the No. 18 flowing water washing tank is externally connected with tap water, the No. 14 flowing water washing tank, the No. 15 flowing water washing tank, the No. 17 flowing water washing tank and the No. 18 flowing water washing tank are reversely connected in series, and the No. 13 mono-nickel salt coloring tank is compatible with the No. 16 medium temperature hole sealing tank;

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

the basic nickel carbonate recovery unit comprises a 1# pump, a recovery tank, a centrifuge, a secondary crystallization tank and a 2# pump which are sequentially arranged, wherein the 1# pump is used for collecting nickel-containing wastewater in a pool A and a pool BNickel-containing wastewater of the nickel-containing wastewater collecting tank B is pumped into the recovery tank, and the recovery tank is used for collecting Ni in the nickel-containing wastewater²⁺The solid basic nickel carbonate is converted, the centrifuge is used for separating the solid basic nickel carbonate and the liquid nickel-containing wastewater, and the secondary crystallization tank is used for separating Ni in the separated nickel-containing wastewater²⁺The 2# pump is used for pumping the secondary crystal in the secondary crystallization tank into the recovery tank and pumping the crystallized nickel-free supernatant into a subsequent wastewater treatment unit.

Further explaining, in the nickel-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 water washing tank, a 2# one-way valve is arranged on a pipeline connecting a water outlet of the 18# flowing water washing tank and a water inlet of the 17# flowing water washing tank, a 3# one-way valve is arranged on a pipeline connecting a water inlet of the 15# flowing water washing tank and a water outlet of the 17# flowing water washing tank, and a 4# one-way valve is arranged between the water outlet of the 15# flowing water washing tank and the water inlet of the 14# flowing water washing tank.

Further explaining, in the nickel-containing wastewater collection unit, a water inlet of the nickel-containing wastewater collection tank A, a water inlet of the nickel-containing wastewater collection tank 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-containing wastewater collection tank A, and a No. 7 valve is arranged at one end of the three-way pipe connected with the nickel-containing wastewater collection tank B;

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

Further, in the basic nickel carbonate recovery unit, a pipeline connecting a water outlet of the pump 1 and a water inlet of the recovery tank is provided with a valve 10, a pipeline connecting a water outlet of the recovery tank and a water inlet of the centrifuge is provided with a valve 11, the centrifuge is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the centrifuge is connected with the water inlet of the 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 secondary crystallization tank, and a crystallization output port is arranged at the bottom of the secondary crystallization tank; the pipeline that the first supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 12# one-way valve, the pipeline that the second supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 13# valve, the pipeline that the third supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 14# valve, the pipeline that the crystallization delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 15# valve, the pipeline that the first delivery port of 2# pump and the water inlet of retrieving the jar are connected is equipped with 16# valve, the second delivery port of 2# pump with the pipeline that the water inlet of wastewater treatment unit is connected is equipped with 17# valve.

Further explaining, the inside of the recovery tank is provided with # 1 electric stirring, and the inside of the secondary crystallization tank is provided with # 2 electric stirring.

The method for recovering the single nickel salt coloring and medium temperature hole sealing agent in the aluminum processing comprises the following steps:

firstly, intercepting nickel-containing wastewater, namely opening a 1# valve and a 5# valve, wherein water enters from the 1# valve, flows into a 14# flowing water washing tank through a 2# one-way valve, a 3# one-way valve and a 4# one-way valve in sequence, flows out from the 5# valve, and only one piece of cleaning water flows in series in a reverse direction; after coloring the aluminum alloy in a 13# single nickel salt coloring tank, dripping for 30 s; entering a No. 14 flowing water washing tank and a No. 15 flowing water washing tank, washing for 60s, and dripping for 30 s; entering a No. 16 medium temperature hole sealing groove, sealing holes for 15min, and dripping for 30 s; entering a No. 17 flowing water washing tank and a No. 18 flowing water washing tank, washing for 60s, and dripping for 30 s;

step two, collecting nickel-containing wastewater, namely opening a No. 6 valve or a No. 7 valve, and enabling the wastewater flowing out of the No. 14 flowing water washing tank to flow into a nickel-containing wastewater collecting tank A or B;

step three, recovering basic nickel carbonate, namely opening an 8# valve or a 9# valve, opening a 1# pump, opening a 10# valve, closing a 11# valve, and pumping the wastewater in the nickel-containing wastewater collection pool A or B into a recovery tank; starting No. 1 electric stirring, slowly adding sodium carbonate while detecting pH value, stopping adding sodium carbonate until pH value is 9.0, stirring for 30min, recovering Ni²⁺Reacting to generate basic nickel carbonate; opening a No. 11 valve, and opening a centrifugal machine to make the nickel-containing wastewater solid and liquidSeparating and recovering solid basic nickel carbonate, and enabling liquid nickel-containing wastewater to flow into a secondary crystallization tank for later use;

rinsing the basic nickel carbonate, adding pure water for wetting, slowly adding glacial acetic acid (98%), and reacting under the condition of excessive basic nickel carbonate to generate a nickel acetate solution;

step five, modifying the hole sealing agent, namely titrating the concentration of the nickel acetate solution and adding triethanolamine and isobutanol according to the medium-temperature hole sealing control index to form the hole sealing agent which can be directly added into the 16# medium-temperature hole sealing groove.

Further, in the fifth step, the concentration ratio of the nickel acetate solution to triethanolamine is 10:1, and the concentration ratio of the nickel acetate solution to isobutanol is 10: 1.

Further explaining, in the third step, the method also comprises the steps of wastewater recovery treatment and secondary crystallization, wherein a 12# valve, a 13# valve, a 14# valve are opened, a 2# pump is started, a 17# valve is opened, a 15# valve and a 16# valve are closed, and the nickel-free supernatant in the secondary crystallization tank is pumped into a wastewater treatment center for neutralization treatment; closing the 12# valve or the 13# valve or the 14# valve, closing the 17# valve, opening the 15# valve and the 16# valve, opening the 2# electric stirring, and pumping the secondary crystal at the bottom of the secondary crystallization tank into the recovery tank for secondary recovery of the basic nickel carbonate.

Further, in the fourth step, the pH value of the generated nickel acetate solution is more than 6.

Further, the thickness of the oxide film on the surface of the aluminum alloy is 15 micrometers.

The invention has the beneficial effects that:

1. the nickel-containing wastewater interception unit is arranged for the first time, so that when the colored hole sealing aluminum product is produced, nickel-containing wastewater is intercepted by the water washing tank and is treated independently, the trouble of treating massive wastewater after mixing with other water is avoided, and the environmental protection cost for treating the nickel-containing wastewater is greatly reduced;

2. the method is characterized in that a coloring hole sealing water reverse series connection mode is adopted in a nickel-containing wastewater interception unit for the first time, so that when a coloring hole sealing aluminum product is produced, a flowing water washing tank is arranged behind a 13# single nickel salt coloring tank, a flowing water washing tank is arranged behind a 16# medium temperature hole sealing tank, two sets of cleaning water are independent from each other, 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 invention, the hole sealing and the coloring water are reversely connected in series for the first time, so that half of the water can be effectively reduced, and a solid foundation is laid for online independent treatment of nickel-containing wastewater and equipment miniaturization;

3. firstly, a nickel-containing wastewater collection unit is arranged on line, so that the nickel-containing wastewater collection unit is prevented from being mixed with other water for independent treatment;

4. firstly, arranging a basic nickel carbonate recovery unit on line, pumping wastewater of a nickel-containing wastewater collection pool A or B into a reaction tank, and recovering Ni²⁺Basic nickel carbonate is generated through reaction, and solid-liquid separation is realized;

5. firstly, adding sodium carbonate into a reaction tank of a basic nickel carbonate recovery unit, and recovering Ni by using the sodium carbonate²⁺Basic nickel carbonate is generated through the reaction, and the reaction end point is the pH value of 9.0, which is beneficial to the recovery of the basic nickel carbonate;

6. wastewater treatment and secondary crystallization recovery are firstly arranged, supernatant in a secondary crystallization tank is pumped into a wastewater treatment center for neutralization treatment, and secondary crystals at the bottom of the secondary crystallization tank are pumped into a reaction tank again to realize secondary recovery of basic nickel carbonate;

7. the basic nickel carbonate recovered by the basic nickel carbonate recovery unit is rinsed and not dried for the first time, and reacts with glacial acetic acid (98%), and a nickel acetate solution with the pH value of more than 6 is generated through effective reaction under the condition of excessive basic nickel carbonate;

8. the method is characterized in that a medicament compatibility principle is utilized for the first time, and a nickel acetate solution with the pH value larger than 6 generated by reaction is transformed into a hole sealing agent for grooving and adding a 16# medium-temperature hole sealing groove, so that the recycling of solid hazardous waste is realized.

Drawings

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 a slot arrangement;

FIG. 7 is a schematic diagram of a system for recovering a single nickel salt coloring and a moderate temperature sealing agent 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 invention relates to a large source of toxic waste residues generated in the aluminum processing industry, namely nickel-containing toxic waste residues generated by oxidation coloring hole sealing, wherein the waste residues account for 4 percent of the total amount of the waste residues of surface treatment of aluminum processing enterprises, about 4 ten thousand tons of the waste residues, about 1600 ten thousand tons of water is used, and the problem of waste water and waste residues is very prominent.

The method is realized according to the following theoretical basis, a recovery system, a recovery method and quantitative and qualitative analysis of the mono-nickel salt hole sealing agent:

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

The traditional oxidation coloring hole sealing process flow and the slot position layout 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# coloring slot and a 16# hole sealing slot contain nickel salt, and the subsequent water washing slots bring nickel-containing wastewater into a wastewater treatment center to generate nickel-containing toxic waste residues. The 13# -18 slot related by the invention has the following functions:

13# coloring tank

The purpose of this groove is in order to color the oxide film, improve the decorative of 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 nickel sulfate

Boric acid 50g/L (1)

pH 3.5-4.5

The temperature is 20-25 DEG C

The time is 30s-15min

The mono-nickel salt coloring bath solution is very stable, but requires high purity of chemical agents and weak pollution resistance, and requires that No. 12 and No. 11 rinsing baths 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:

stannous sulfate 10g/L

Nickel sulfate 25g/L sulfuric acid 18g/L

pH 0.8-1.2 (2) temperature 20-25 deg.C

The time is 30s-15min

Voltage 14-16V

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 =1.0, oxygen electrolytically released by oxygen or hydroxyl in the air is easily oxidized to high-valent tin ions, and further hydrolyzed to generate white stannic acid precipitates, which slightly affect the quality of the colored film and largely 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, 6-8 g/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 roles of improving uniformity, preventing stannous from hydrolysis and the like, but the prior coloring tank has insufficient complexing ability, and stannous can be oxidized and hydrolyzed as required, so that proper chelating agent needs to be selected to completely stabilize stannous sulfate. 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 concentration of the bath solution uniform, the coloring bath solution should be stirred during production, although a circulating pump for directly stirring with air is avoided, the chance of the bath solution contacting with air is increased, and the reaction that the divalent tin is easily oxidized into the tetravalent tin occurs during the contact with 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⁺Ionic 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. In addition to additives such as phenol, sulfuric acid, boric acid, etc., oxidation inhibitors such as ascorbic acid, diphenyl, hydroquinone, etc. may be added. 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 improve the conductivity of the solution 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.

The various factors are comprehensively considered, and the formula design of the coloring stabilizer must meet four requirements of 1, improving the uniform coloring performance; 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 Sn content of the oxide film linearly increases with time, and the relation is W = 4.4 + 2.5 t (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. Therefore, pH values of 0.8 to 1.0 are important factors for generating a uniform color of champagne-colored aluminum 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 2 min, 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.

14# and 15# running water wash tank

The two rinsing tanks are provided for cleaning the residual coloring agent carried out from the coloring tank and protecting the hole sealing tank. Similarly, tap water enters from the No. 15 tank and exits from the No. 14 tank and is reversely connected in series, the water consumption is about 2.0 to 3.0 tons per ton of wood, the water consumption is too large, and the discharged waste water containing tin and nickel increases the environmental protection treatment pressure.

16# hole sealing groove

The purpose of the groove is to seal the micropores of the oxide film and ensure the corrosion resistance. 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 nickel acetate and an additive, the hole sealing is fast, less ash is attached, a film is not cracked, but nickel is contained, 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:

nickel acetate 5g/L

Triethanolamine 0.5g/L

Isobutanol 0.5g/L

pH5.5-6.5 (7) temperature 50-60 deg.C

The time is 10-25min

17# and 18# running water wash tank

The two rinsing baths are arranged for cleaning the hole sealing bath to bring out a residual agent containing nickel, so that the aluminum product is protected from being corroded after leaving the factory. Similarly, tap water enters from the No. 18 tank and exits from the No. 17 tank and is reversely connected in series, the water consumption is about 2.0 to 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 clean civilization production, oxidation line 13-18# cells need to be greatly improved in several respects:

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, 13# and 16# are nickel-containing bath solution, the aluminum material is colored and hole-sealed and then directly enters four flowing rinsing baths of 14#, 15#, 17# and 18# to bring nickel-containing wastewater into a wastewater center to pollute cleaning water for other processes of the whole oxidation line; after mixing, the nickel-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. And a 14# rinsing tank and a 15# rinsing tank are arranged behind the 13# coloring tank, so that residual coloring agent brought out from the coloring tank is cleaned, and the hole sealing tank is protected. Tap water enters from the No. 15 tank and exits from the No. 14 tank and is connected in series in a reverse direction, the water consumption is about 2.0 to 3.0 tons per ton of wood, the water consumption is too large, and the discharged waste water contains tin and nickel, so that the environmental protection treatment pressure is increased; and a 17# rinsing tank and a 18# rinsing tank are arranged behind the 16# hole sealing tank, so that a residual agent containing nickel is brought out from the hole sealing tank in a cleaning manner, and the aluminum product is protected from being corroded after leaving a factory. Tap water enters from the No. 18 tank and exits from the No. 17 tank and is connected in series in a reverse direction, the water consumption is about 2.0 to 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. 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 wastewater and the waste residues needs to be abandoned, the nickel-containing wastewater and the waste residues 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 nickel-containing chemical products is realized. The design concept of the traditional process is unreasonable, 13# and 16# are nickel-containing bath solution, the aluminum material is colored and hole-sealed and then directly enters four flowing rinsing baths of 14#, 15#, 17# and 18# to bring nickel-containing wastewater into a wastewater center to pollute cleaning water for other processes of the whole oxidation line; the wastewater center performs neutralization, precipitation and filter pressing on the wastewater to obtain nickel-containing solid waste residue; the mass nickel-containing waste residues are definitely specified as hazardous waste by the national ministry of environmental protection; to treat these nickel-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-containing products are actively recycled on line, waste is changed into valuable, and resource utilization of hazardous waste is realized.

Modern aluminum processing enterprises have urgent need for treatment of nickel-containing wastewater and waste residues generated by oxidation, coloring and hole sealing, while the traditional method for treating the nickel-containing wastewater and waste residues generated by mixing large amount of cleaning water is too simple, so that a large amount of nickel-containing waste residues are generated and treated, and the society pays expensive environmental protection cost for the treatment.

A recovery system and a method of single nickel salt coloring and medium temperature hole sealing agent in aluminum processing are a new process which is created after unprecedented system research is carried out on a coloring hole sealing treatment process with 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 is fully known and researched for many years:

1) and coloring and washing with water for separate collection and treatment. According to the formula (1), the coloring control indexes of the mono-nickel salt are that nickel sulfate is 150g/L, boric acid is 50g/L, pH is 3.5-4.5, temperature is 20-25 ℃, and time is 30s-15 min. The mono-nickel salt coloring bath solution is very stable, but requires high purity of chemical agents and weak pollution resistance, and requires that No. 12 and No. 11 rinsing baths before coloring are washed by flowing pure water; after the aluminum material is colored for 30s-15min, hanging trickling is carried out for 30s, the aluminum material enters a 14# flowing water washing tank and is cleaned for 1min, hanging trickling is carried out for 30s, the aluminum material enters a 15# flowing water washing tank and is cleaned for 1min, hanging trickling is carried out for 30s, and the aluminum material enters a 16# hole sealing tank, so that the coloring and water washing process is completed. When cleaning is carried out after coloring, nickel sulfate and boric acid contained in the coloring liquid are brought into No. 14 and No. 15 flowing water washing tanks to pollute flowing cleaning water; the pH value of 13# coloring tank is 3.5-4.5, the pH value of water inlet of 15# tank is 6.0-7.0, so that the pH values of 14# and 15# are 3.5-7.0, and the nickel sulfate and boric acid in the interval are stable and do not decompose, and can be separately collected and treated.

2) And hole sealing water washing is independently recovered.

According to the formula (7), the medium-temperature hole sealing control indexes 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 time is 10-25 min. 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 and is washed for 1min, hanging trickling flows for 30s, the aluminum material enters a No. 18 flowing water washing tank and is washed for 1min, hanging trickling flows for 30s, and the aluminum material enters an air drying area to complete hole sealing and water washing processes. When cleaning is carried out after hole sealing, nickel acetate, triethanolamine and isobutanol contained in the hole sealing liquid are brought into No. 17 and No. 18 flowing water washing tanks to pollute flowing cleaning water; the pH value of the 16# hole sealing groove is 5.5-6.5, the pH value of the water inlet of the 18# groove is 6.0-7.0, so the pH values of 17# and 18# are 5.5-7.0, and the nickel acetate, triethanolamine and isobutanol in the interval are stable and can be collected and treated independently without decomposition.

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 cleaning is carried out after coloring, nickel sulfate and boric acid contained in the coloring liquid are brought into No. 14 and No. 15 flowing water washing tanks; pH values of No. 14 and No. 15 are 3.5-7.0, and nickel sulfate and boric acid in the interval are stable and are not decomposed; when cleaning is carried out after hole sealing, nickel acetate, triethanolamine and isobutanol contained in the hole sealing liquid are brought into No. 17 and No. 18 flowing water washing tanks; pH values of 17# and 18# are 5.5-7.0, and nickel acetate, triethanolamine and isobutanol in the interval are stable and do not decompose. The tap water inlet of the No. 15 groove is closed, and the cleaning water at the water outlet of the No. 17 groove is connected in series in a reversed phase manner to the water inlet of the No. 15 groove, so that the cleaning water enters from the No. 18 groove, passes through the No. 17 groove, the No. 15 groove and the No. 14 groove, and finally flows out from the water outlet of the No. 14 groove in a reversed large series manner. In the serial mode, nickel acetate, triethanolamine and isobutanol contained in the No. 17 and No. 18 flowing water washing tanks are brought into the No. 15 tank and the No. 14 tank, and two aspects need to be examined, namely whether the No. 14 and No. 15 tanks are turbid or not so as to make the aluminum material become grey; secondly, whether the hole sealing capability of the 16# groove is influenced.

A. Stability analysis of 14#, 15# cells.

The pH values of No. 14 and No. 15 are 3.5-7.0, the nickel sulfate, the boric acid, the nickel acetate, the triethanolamine and the isobutanol in the interval are very stable, no turbid matter is generated, the aluminum material cannot be coated with ash, and the reverse serial connection water washing is feasible;

B. and analyzing the influence of the 14# and 15# grooves on the hole sealing groove.

When cleaning is carried out after coloring, nickel sulfate and boric acid contained in the coloring liquid are brought into No. 14 and No. 15 flowing water washing tanks; the pH values of No. 14 and No. 15 are between 3.5 and 7.0, when the hole sealing is carried out, trace nickel sulfate and boric acid can be brought into a hole sealing groove, and the hole sealing quality is qualified; after reverse series connection water washing, nickel acetate, triethanolamine and isobutanol contained in the No. 17 and No. 18 flowing water washing tanks are brought into the No. 15 tank and the No. 14 tank, and similarly, trace nickel acetate, triethanolamine and isobutanol are brought back to the No. 16 hole sealing tank, and the trace nickel acetate, the triethanolamine and the isobutanol are inherent components of the hole sealing tank, so that the hole sealing capability of the No. 16 tank is absolutely not influenced according to a self-compatibility principle, and reverse series connection water washing is feasible.

Quantitative and qualitative analysis of pore sealing agent produced by coloring of mono-nickel salt and recovery of pore sealing cleaning water

After reverse-phase series water washing, the No. 14 water outlet contains nickel sulfate, boric acid, nickel acetate, triethanolamine and isobutanol, the concentration of the chemical agent at the No. 14 water outlet is about 2 percent of that of the coloring groove and the hole sealing groove, namely 3g/L of nickel sulfate and 1g/L of boric acid, calculated according to the formulas (1) and (7), 50Kg of groove liquid is brought out by each ton of aluminum material, and 2.5 tons of washing water is consumed

0.1g/L of nickel acetate, 0.01g/L of triethanolamine and 0.01g/L of isobutanol. Considering that the coloring of the mono-nickel salt is generally equipped with a nickel recovery device, the nickel sulfate brought out actually is much lower. The treatment mode of each chemical component is as follows:

1. nickel contained in the nickel sulfate and the nickel acetate is crystallized and separated out.

Controlling coloring and hole sealing grooves according to (1) and (7), reversely connecting in series to wash to produce coloring hole sealing materials, taking 1L of 14# water outlet cleaning water, and detecting the concentration of a medicament as follows:

nickel sulfate 1.6g/L

Boric acid 0.55g/L

Nickel acetate 0.11g/L (8)

Triethanolamine 0.01g/L

Isobutanol 0.01g/L

pH 5.15

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

when the pH value is lower than 7.0, the tank liquor is clear, no precipitate exists and no precipitate exists due to the complexation of triethanolamine;

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↓ (9)

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.

2. Boric acid, triethanolamine and isobutanol do not react and remain in the liquid.

According to formula (8), with the addition of sodium carbonate, the pH is continuously increased, according to formula (9), Ni²⁺Continuously react to generate NiCO₃、Ni(OH)₂Or NiCO₃-2Ni(OH)₂-4H₂O, but the boric acid, the triethanolamine and the isobutanol do not decompose or precipitate under the condition that the pH value does not exceed 9, and the boric acid, the triethanolamine and the isobutanol do not remain in the liquid.

3. And (3) solid-liquid separation, namely separating boric acid, triethanolamine and isobutanol along with the liquid, and recovering solid basic nickel carbonate.

According to the formula (9), the reaction product is subjected to solid-liquid separation. Boric 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.

4. According to the principle of medicament compatibility, the hole sealing agent is regenerated, and the recycling of solid hazardous waste is realized.

Weighing 100g of basic nickel carbonate product obtained after rinsing and drying (drying only in the metering process of a laboratory, rinsing and cleaning 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 acetic acid (98%), and reacting as follows:

NiCO₃.2Ni(OH)₂.4H₂O+6CH₃COOH=3Ni(CH₃COO)₂+9H₂O+CO₂↑ (10)

100g of basic nickel carbonate, 97.7g of glacial acetic acid (98%) were added to complete the reaction. Taking 95g of glacial acetic acid, and taking excessive basic nickel carbonate, namely, a small amount of solid residues at the bottom of the beaker after the reaction is finished; detecting the pH value of the nickel acetate solution to be 6.19, and meeting the requirement that the pH value of the medium-temperature hole sealing agent is more than 6.0;

because the nickel acetate liquid obtained by the formula (10) is generated by the reaction of nickel recovered from a 14# rinsing bath, and the 14# and 15# baths have limited influence on the hole sealing capability of a 16# hole sealing bath and are basically compatible, the nickel acetate produced by the formula (10) can be completely transformed according to a hole sealing agent and recycled to the hole sealing bath. According to the formula (7), the modification method comprises the following steps:

A. titrating the concentration of nickel acetate to obtain X (g/L);

B. supplementing triethanolamine X/10(g/L) (11)

C. Supplementing isobutanol X/10(g/L)

The hole sealing agent reconstructed according to the formula (11) can be completely used as a slot of a 16# hole sealing groove and added by referring to the formula (7); considering that the working index of the 16# groove is pH5.5-6.5 and the temperature is 50-60 ℃, the nickel acetate recovered by the formula (10) already meets the requirement of pH value; when the hole sealing is carried out at the temperature of 50-60 ℃, a large amount of water is evaporated, the liquid level of a hole sealing groove becomes shallow, and the liquid hole sealing agent produced according to the formula (11) is added to just supplement the concentration and the liquid level of the agent.

Third, the experimental result of producing the hole sealing agent by coloring the mono-nickel salt and recycling the hole sealing cleaning water

The invention firstly obtains basic nickel carbonate according to the formula (9), then produces nickel acetate according to the formula (10), and finally prepares the medium-temperature hole sealing agent according to the formula (11). In the series of experiments, the hole sealing capability of the medium-temperature hole sealing agent produced according to the formula (11) is respectively inspected according to the medium-temperature hole sealing groove control index provided by the formula (7).

1. The influence of the concentration of the hole sealing agent on the hole sealing quality.

Taking nickel acetate (2, 3, 4, 5, 6 and 7g/L, triethanolamine and isobutanol are one tenth of the concentration of nickel acetate, and the same is used below) at the pH value of 6.0 and the temperature of 55 ℃; the thickness of the oxide film is 15 microns, the hole sealing time is 15 minutes, the hole sealing quality is detected according to the ISO3210 international standard, and the result is shown in Table 1:

table 1 effect of the concentration of the pore sealing agent on the quality of the sealing

2. Influence of the pH value of the hole sealing groove on the hole sealing quality.

Taking 5g/L nickel acetate (triethanolamine and isobutanol are one tenth of the concentration of the nickel acetate, the same below), and controlling the temperature at 55 ℃ and the pH value at 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0; the thickness of the oxide film is 15 microns, the hole sealing time is 15 minutes, the hole sealing quality is detected according to the ISO3210 international standard, and the result is shown in Table 2:

table 2 influence of the pH value of the hole sealing groove on the hole sealing quality

3. The influence of the hole sealing temperature on the hole sealing quality.

Taking 5g/L nickel acetate (triethanolamine and isobutanol are one tenth of the concentration of the nickel acetate, the same below), pH6.0, and temperature 40, 45, 50, 55, 60, 65 ℃; the thickness of the oxide film is 15 microns, the hole sealing time is 15 minutes, the hole sealing quality is detected according to the ISO3210 international standard, and the result is shown in Table 3:

TABLE 3 influence of hole sealing temperature on hole sealing quality

4. The influence of hole sealing time on hole sealing quality.

Taking 5g/L nickel acetate (triethanolamine and isobutanol are one tenth of the concentration of the nickel acetate, the same below), pH6.0, and temperature 55 deg.C; taking the oxide film with the thickness of 15 microns, the hole sealing time of 5 minutes, 8 minutes, 11 minutes, 14 minutes, 17 minutes and 20 minutes, and detecting the hole sealing quality according to the ISO3210 international standard, wherein the results are shown in Table 4:

TABLE 4 influence of hole sealing time on hole sealing quality

Fourth, analysis of experimental results of producing hole sealing agent by coloring of mono-nickel salt and recycling of hole sealing cleaning water

According to the reaction formulas (8) to (11), experiments 1 to 4 and the detection results, the following analysis can be made:

1. according to the formula (8), by utilizing the principle that the hole sealing water washing is compatible with the hole sealing groove, the hole sealing water can be reversely connected in series to the coloring water, two sets of water washing are combined into one, half of water is saved, and the nickel-containing wastewater is intercepted and recovered at the water outlet of the 14# groove;

2. according to the formula (9), the intercepted nickel-containing wastewater can be independently treated on line, the industrial-grade basic nickel carbonate is recovered, the nickel-containing solid hazardous waste is converted into a high-value chemical raw material, and the resource utilization of the solid hazardous waste is realized;

3. according to the formula (10), the recovered basic nickel carbonate can be converted into a nickel acetate solution, and under the condition of excessive basic nickel carbonate, the pH value of a reaction product is greater than 6.0, so that the requirement of subsequent conversion into a hole sealing agent is met;

4. according to the formula (11), the nickel acetate solution can be converted into a liquid hole sealing agent according to the requirement of the formula (7), and the liquid hole sealing agent is directly added into a hole sealing groove; the hole sealing groove is sealed at medium temperature, has a certain evaporation amount, and the liquid hole sealing agent just supplements the concentration and the liquid level of the medicament, so that the trouble of evaporating and crystallizing the nickel acetate solution is saved, and the manufacturing cost of the hole sealing agent is greatly saved;

5. according to the series of experimental results 1-4, the medium-temperature hole sealing agent prepared according to the formula (11) can completely meet the hole sealing requirement within the control index range specified by the formula (7).

Fifthly, according to the reaction formulas (8) - (11), experiments 1-4 and detection results, by combining the practical continuous production of coloring hole sealing, factors such as medicament recovery and water interception, the number of groove positions and the like, the recovery system and the recovery method of the mono-nickel salt coloring and medium-temperature hole sealing reagent in aluminum processing are configured as shown in fig. 7:

in order to realize the goals of saving water in long-term large-scale production, recovering nickel-containing wastewater on line and independently converting nickel-containing solid hazardous waste, 6 groove positions are configured in figure 7, two reagent grooves are contained, 4 flowing water washing grooves are arranged, and the parts contacted with the groove liquid are all designed according to acid resistance.

The recovery system of the single nickel salt coloring and medium temperature hole sealing agent in the aluminum processing comprises a nickel-containing wastewater interception unit, a nickel-containing wastewater collection unit and an alkali nickel carbonate recovery unit from upstream to downstream in sequence; the nickel-containing wastewater interception unit comprises a 13# single nickel salt coloring tank, a 14# flowing water washing tank, a 15# flowing water washing tank, a 16# medium temperature hole sealing tank, a 17# flowing water washing tank and a 18# flowing water washing tank which are sequentially arranged; the No. 18 flowing water washing tank is externally connected with tap water, the No. 14 flowing water washing tank, the No. 15 flowing water washing tank, the No. 17 flowing water washing tank and the No. 18 flowing water washing tank are reversely connected in series, and the No. 13 mono-nickel salt coloring tank is compatible with the No. 16 medium temperature hole sealing tank;

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

basic nickel carbonate recovery unit is including the 1# pump, recovery tank, centrifuge, secondary crystallizer and the 2# pump of sequential configuration, 1# pump is used for the nickeliferous waste water pump income of nickeliferous waste water collecting pit A and nickeliferous waste water collecting pit B recovery tank, recovery tank is used for the Ni in the nickeliferous waste water²⁺The solid basic nickel carbonate is converted, the centrifuge is used for separating the solid basic nickel carbonate and the liquid nickel-containing wastewater, and the secondary crystallization tank is used for separating Ni in the separated nickel-containing wastewater²⁺The 2# pump is used for pumping the secondary crystal in the secondary crystallization tank into the recovery tank and combiningPumping the crystallized nickel-free supernatant into a subsequent wastewater treatment unit.

On the basis of compatibility of medicaments, the nickel-containing wastewater interception unit is arranged and is responsible for intercepting medicaments brought out by the 13# mono-nickel salt coloring tank and the 16# medium-temperature hole sealing tank and reserving the medicaments in the 14# flow rinsing tanks, the 15# flow rinsing tanks, the 17# flow rinsing tanks and the 18# flow rinsing tanks, so that the trouble of treating massive wastewater after mixing with other water is avoided, and the environmental-friendly cost for treating the nickel-containing wastewater is greatly reduced; the nickel-containing wastewater interception unit adopts a coloring hole sealing water reverse series connection mode, and the hole sealing water and the coloring water are reversely connected in series, so that half of water is reduced, and a solid foundation is laid for online independent treatment of nickel-containing wastewater and equipment miniaturization; and is responsible for recovering Ni by arranging a basic nickel carbonate recovery unit on line²⁺And basic nickel carbonate is generated through reaction and is transformed into hole sealing liquid, so that recycling of solid hazardous waste is realized.

Further explaining, in the nickel-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 water washing tank, a 2# one-way valve is arranged on a pipeline connecting a water outlet of the 18# flowing water washing tank and a water inlet of the 17# flowing water washing tank, a 3# one-way valve is arranged on a pipeline connecting a water inlet of the 15# flowing water washing tank and a water outlet of the 17# flowing water washing tank, and a 4# one-way valve is arranged between the water outlet of the 15# flowing water washing tank and the water inlet of the 14# flowing water washing tank.

Further explaining, in the nickel-containing wastewater collection unit, a water inlet of the nickel-containing wastewater collection tank A, a water inlet of the nickel-containing wastewater collection tank 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-containing wastewater collection tank A, and a No. 7 valve is arranged at one end of the three-way pipe connected with the nickel-containing wastewater collection tank B;

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

Further, in the basic nickel carbonate recovery unit, a pipeline connecting a water outlet of the pump 1 and a water inlet of the recovery tank is provided with a valve 10, a pipeline connecting a water outlet of the recovery tank and a water inlet of the centrifuge is provided with a valve 11, the centrifuge is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the centrifuge is connected with the water inlet of the 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 secondary crystallization tank, and a crystallization output port is arranged at the bottom of the secondary crystallization tank; the pipeline that the first supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 12# one-way valve, the pipeline that the second supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 13# valve, the pipeline that the third supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 14# valve, the pipeline that the crystallization delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 15# valve, the pipeline that the first delivery port of 2# pump and the water inlet of retrieving the jar are connected is equipped with 16# valve, the second delivery port of 2# pump with the pipeline that the water inlet of wastewater treatment unit is connected is equipped with 17# valve.

Further explaining, the inside of the recovery tank is provided with # 1 electric stirring, and the inside of the secondary crystallization tank is provided with # 2 electric stirring.

By means of the system arrangement, the system can treat about 1600 ten thousand tons of nickel-containing wastewater generated by oxidation, coloring and hole sealing in the aluminum processing industry on line, convert about 4 ten thousand tons of nickel-containing toxic waste residues and generate about 5 ten thousand tons of basic nickel carbonate. The operation flow of the invention comprises the following steps:

firstly, intercepting nickel-containing wastewater, namely opening a 1# valve and a 5# valve, wherein water enters from the 1# valve, flows into a 14# flowing water washing tank through a 2# one-way valve, a 3# one-way valve and a 4# one-way valve in sequence, flows out from the 5# valve, and only one piece of cleaning water flows in series in a reverse direction; after coloring the aluminum alloy in a 13# single nickel salt coloring tank, dripping for 30 s; entering a No. 14 flowing water washing tank and a No. 15 flowing water washing tank, washing for 60s, and dripping for 30 s; entering a No. 16 medium temperature hole sealing groove, sealing holes for 15min, and dripping for 30 s; entering a No. 17 flowing water washing tank and a No. 18 flowing water washing tank, washing for 60s, and dripping for 30 s;

step two, collecting nickel-containing wastewater, namely opening a No. 6 valve or a No. 7 valve, and enabling the wastewater flowing out of the No. 14 flowing water washing tank to flow into a nickel-containing wastewater collecting tank A or B;

step three, recovering basic nickel carbonate, namely opening an 8# valve or a 9# valve, opening a 1# pump, opening a 10# valve, closing a 11# valve, and pumping the wastewater in the nickel-containing wastewater collection pool A or B into a recovery tank; starting No. 1 electric stirring, slowly adding sodium carbonate while detecting pH value, stopping adding sodium carbonate until pH value is 9.0, stirring for 30min, recovering Ni²⁺Reacting to generate basic nickel carbonate; opening a No. 11 valve, starting a centrifugal machine to separate solid and liquid of the nickel-containing wastewater, recovering solid basic nickel carbonate, and enabling the liquid nickel-containing wastewater to flow into a secondary crystallization tank for later use;

rinsing the basic nickel carbonate, adding pure water for wetting, slowly adding glacial acetic acid (98%), and reacting under the condition of excessive basic nickel carbonate to generate a nickel acetate solution;

step five, modifying the hole sealing agent, namely titrating the concentration of the nickel acetate solution and adding triethanolamine and isobutanol according to the medium-temperature hole sealing control index to form the hole sealing agent which can be directly added into the 16# medium-temperature hole sealing groove.

Further, in the fifth step, the concentration ratio of the nickel acetate solution to triethanolamine is 10:1, and the concentration ratio of the nickel acetate solution to isobutanol is 10: 1.

Further explaining, in the third step, the method also comprises the steps of wastewater recovery treatment and secondary crystallization, wherein a 12# valve, a 13# valve, a 14# valve are opened, a 2# pump is started, a 17# valve is opened, a 15# valve and a 16# valve are closed, and the nickel-free supernatant in the secondary crystallization tank is pumped into a wastewater treatment center for neutralization treatment; closing the 12# valve or the 13# valve or the 14# valve, closing the 17# valve, opening the 15# valve and the 16# valve, opening the 2# electric stirring, and pumping the secondary crystal at the bottom of the secondary crystallization tank into the recovery tank for secondary recovery of the basic nickel carbonate.

Further, in the fourth step, the pH value of the generated nickel acetate solution is more than 6.

Further, the thickness of the oxide film on the surface of the aluminum alloy is 15 micrometers.

Examples

On the basis of compatibility of the cleaning water and the medicament, the operation of each system (as shown in figure 7) is the key to the successful implementation of the invention in order to achieve the aims of halving the cleaning water, recovering the basic nickel carbonate and preparing the hole sealing liquid.

Example 1 (operation for retaining Nickel-containing waste Water)

Opening a 1# valve and a 5# valve, wherein water enters from the 1# valve, flows into a 14# flowing water washing tank through a 2# one-way valve, a 3# one-way valve and a 4# one-way valve in sequence, flows out from the 5# valve, and only one piece of washing water flows in series in a reverse direction; after coloring the aluminum alloy with the thickness of 15 microns by a 13# single nickel salt coloring tank, dripping for 30 s; entering a No. 14 flowing water washing tank and a No. 15 flowing water washing tank, washing for 60s, and dripping for 30 s; entering a No. 16 medium temperature hole sealing groove, sealing holes for 15min, and dripping for 30 s; entering a No. 17 flowing water washing tank and a No. 18 flowing water washing tank, washing for 60s, dripping for 30s, and finishing the nickel-containing wastewater interception operation;

example 2 (operation for collecting Nickel-containing waste Water)

Opening a No. 6 valve or a No. 7 valve, and enabling the wastewater flowing out of the No. 14 flowing water washing tank to flow into a nickel-containing wastewater collecting pool A or B to finish the nickel-containing wastewater collecting operation;

example 3 (operation for recovering basic Nickel carbonate)

Opening the 8# valve or the 9# valve, opening the 1# pump, opening the 10# valve, closing the 11# valve, and pumping the wastewater in the nickel-containing wastewater collecting tank A or B into a recovery tank; starting No. 1 electric stirring, slowly adding sodium carbonate while detecting pH value, stopping adding sodium carbonate until pH value is 9.0, stirring for 30min, recovering Ni²⁺Reacting to generate basic nickel carbonate; opening a No. 11 valve, starting a centrifugal machine to separate solid and liquid of the nickel-containing wastewater, recovering solid basic nickel carbonate, and enabling the liquid nickel-containing wastewater to flow into a secondary crystallization tank for later use; completing the recovery operation of the basic nickel carbonate;

example 4 (operation of wastewater treatment and Secondary crystallization)

Opening a 12# valve, a 13# valve or a 14# valve, starting a 2# pump, opening a 17# valve, closing a 15# valve and a 16# valve, and pumping the nickel-free supernatant in the secondary crystallization tank into a wastewater treatment center for neutralization treatment; closing the 12# valve, the 13# valve or the 14# valve, closing the 17# valve, opening the 15# valve and the 16# valve, opening the 2# electric stirring, pumping the secondary crystal at the bottom of the secondary crystallization tank into a recovery tank again for secondary recovery of basic nickel carbonate, and finishing the wastewater treatment and secondary crystallization recovery operations;

example 5 (preparation of Nickel acetate solution satisfying the sealing agent requirement Using recycled basic Nickel carbonate)

Weighing 100g of basic nickel carbonate product obtained after rinsing and drying (drying only in the process of laboratory measurement and rinsing clean in the process of mass production, drying is not needed, and the production cost is saved), adding 100g of pure water for wetting, and carrying out reaction

NiCO₃.2Ni(OH)₂.4H₂O+6CH₃COOH=3Ni(CH₃COO)₂+9H₂O+CO₂↑

100g of basic nickel carbonate, 97.7g of glacial acetic acid (98%) were added to complete the reaction. Slowly adding 95g of glacial acetic acid, and under the condition that the basic nickel carbonate is excessive, namely a small amount of solid residues exist at the bottom of the beaker after the reaction is finished; detecting the pH value of the nickel acetate solution to be 6.19, and meeting the requirement that the pH value of the medium-temperature hole sealing agent is more than 6.0;

example 6 (modified to Medium temperature sealer)

Titrating the prepared nickel acetate solution according to the medium-temperature hole sealing control index to obtain the nickel acetate with the concentration of 28.2 g/L; according to the formula (7), the concentration ratio of the nickel acetate solution to triethanolamine is 10:1, the concentration ratio of the nickel acetate solution to isobutanol is 10:1, and 2.82g/L of triethanolamine and 2.82g/L of isobutanol are added to complete the pore sealing agent transformation of the nickel acetate solution.

Referring to formula (7), this sealant is added to the 16# plugged cell; considering that the working index of the 16# groove is pH5.5-6.5, the hole sealing agent meets the requirement of pH value; when the hole sealing is carried out at the temperature of 50-60 ℃, a large amount of water is evaporated, the liquid level of the hole sealing groove becomes shallow, and the concentration and the liquid level of the medicament are just supplemented by adding the hole sealing agent.

Example 7 (detection of work ability of hole sealing agent in recovery production)

According to the figure 7, continuously producing the colored hole sealing aluminum material, and continuously adding the hole sealing agent manufactured by the invention into a 16# hole sealing groove according to the formula (7) control index; taking hole sealing tank liquor with pH of 6.0, temperature of 55 ℃, nickel acetate 4-6 g/L; taking the oxide film with the thickness of 15 microns and the hole sealing time of 15 minutes, continuously detecting the hole sealing quality according to the ISO3210 international standard, and obtaining the results shown in the following table:

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 (8)

1. The recovery system of single nickel salt colouring and medium temperature hole sealing agent in aluminium processing includes nickeliferous waste water interception unit, nickeliferous waste water collection unit and basic nickel carbonate recovery unit from upper reaches to low reaches in proper order, its characterized in that:

the nickel-containing wastewater interception unit comprises a 13# single nickel salt coloring tank, a 14# flowing water washing tank, a 15# flowing water washing tank, a 16# medium temperature hole sealing tank, a 17# flowing water washing tank and a 18# flowing water washing tank which are sequentially arranged; the No. 18 flowing water washing tank is externally connected with tap water, the No. 14 flowing water washing tank, the No. 15 flowing water washing tank, the No. 17 flowing water washing tank and the No. 18 flowing water washing tank are reversely connected in series, and the No. 13 mono-nickel salt coloring tank is compatible with the No. 16 medium temperature hole sealing tank reagent;

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

the basic nickel carbonate recovery unit comprises a No. 1 pump, a recovery tank, a centrifuge, a secondary crystallization tank and a No. 2 pump which are sequentially configured, wherein the No. 1 pump is used for pumping nickel-containing wastewater of a nickel-containing wastewater collection pool A and a nickel-containing wastewater collection pool B into the recovery tank;

the recovery tank is used for receiving nickel-containing wastewater, adding sodium carbonate until the pH value is 9.0, and recovering Ni²⁺Reacting to generate basic nickel carbonate; the centrifugal machine is used for separating solid basic nickel carbonate and liquid nickel-containing wastewater; the secondary crystallizing tank is used for separating Ni in the nickel-containing wastewater²⁺The secondary crystallization of (2); the 2# pump is used for pumping the secondary crystals in the secondary crystallization tank into the secondary crystallization tankThe recovery tank pumps the crystallized nickel-free supernatant into a subsequent wastewater treatment unit;

rinsing the basic nickel carbonate separated from the centrifuge, adding pure water for wetting, slowly adding glacial acetic acid with the mass fraction of 98%, and reacting under the condition that the basic nickel carbonate is excessive to generate a nickel acetate solution; after the concentration of the nickel acetate solution is titrated according to the medium-temperature hole sealing control index, triethanolamine and isobutanol are added to form a hole sealing agent which can be directly added into a 16# medium-temperature hole sealing groove;

among the unit is held back to nickeliferous waste water, 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# one-way 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 3# one-way valve on the pipeline that the water inlet of the rinsing bath that flows of 15# and the delivery port of the rinsing bath that flows of 17# are connected, be equipped with the 4# one-way valve between the delivery port of the rinsing bath that flows of 15# and the water inlet of the rinsing bath that flows of 14 #.

2. The recovery system of mono-nickel salt coloring and medium temperature hole sealing agents in aluminum processing according to claim 1, characterized in that in the nickel-containing wastewater collection unit, the water inlet of the nickel-containing wastewater collection tank A, the water inlet of the nickel-containing wastewater collection tank B and the water outlet of the No. 14 flowing water washing tank are connected through a three-way pipe, and one end of the three-way pipe connected with the No. 14 flowing water washing tank is provided with a No. 5 valve, one end of the three-way pipe connected with the nickel-containing wastewater collection tank A is provided with a No. 6 valve, and one end of the three-way pipe connected with the nickel-containing wastewater collection tank B is provided with a No. 7 valve;

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

3. The recovery system of mono-nickel salt coloring and medium temperature hole sealing agents in aluminum processing according to claim 2, wherein in the basic nickel carbonate recovery unit, a pipeline connecting the water outlet of the 1# pump and the water inlet of the recovery tank is provided with a 10# valve, a pipeline connecting the water outlet of the recovery tank and the water inlet of the centrifuge is provided with a 11# valve, the centrifuge is provided with a solid separation material port and a liquid separation material port, and the liquid separation material port of the centrifuge is connected with the water inlet of the 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 secondary crystallization tank, and a crystallization output port is arranged at the bottom of the secondary crystallization tank; the pipeline that the first supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 12# one-way valve, the pipeline that the second supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 13# valve, the pipeline that the third supernatant delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 14# valve, the pipeline that the crystallization delivery outlet of secondary crystallizer and the water inlet of 2# pump are connected is equipped with 15# valve, the pipeline that the first delivery port of 2# pump and the water inlet of retrieving the jar are connected is equipped with 16# valve, the second delivery port of 2# pump with the pipeline that the water inlet of wastewater treatment unit is connected is equipped with 17# valve.

4. The system for recovering single nickel salt coloring and medium-temperature hole sealing agents in aluminum processing according to claim 3, wherein:

the inside of recovery jar is provided with # 1 electric stirring, the inside of secondary crystallizer is provided with # 2 electric stirring.

5. The method for recovering the system for coloring the mono-nickel salt and the moderate-temperature hole sealing agent in the aluminum processing according to claim 4, which comprises the following steps:

firstly, intercepting nickel-containing wastewater, namely opening a 1# valve and a 5# valve, wherein water enters from the 1# valve, flows into a 14# flowing water washing tank through a 2# one-way valve, a 3# one-way valve and a 4# one-way valve in sequence, flows out from the 5# valve, and only one piece of cleaning water flows in series in a reverse direction; after coloring the aluminum alloy in a 13# single nickel salt coloring tank, dripping for 30 s; entering a No. 14 flowing water washing tank and a No. 15 flowing water washing tank, washing for 60s, and dripping for 30 s; entering a No. 16 medium temperature hole sealing groove, sealing holes for 15min, and dripping for 30 s; entering a No. 17 flowing water washing tank and a No. 18 flowing water washing tank, washing for 60s, and dripping for 30 s;

step two, collecting nickel-containing wastewater, namely opening a No. 6 valve or a No. 7 valve, and enabling the wastewater flowing out of the No. 14 flowing water washing tank to flow into a nickel-containing wastewater collecting tank A or B;

step three, recovering basic nickel carbonate, namely opening an 8# valve or a 9# valve, opening a 1# pump, opening a 10# valve, closing a 11# valve, and pumping the wastewater in the nickel-containing wastewater collection pool A or B into a recovery tank; starting No. 1 electric stirring, slowly adding sodium carbonate while detecting pH value, stopping adding sodium carbonate until pH value is 9.0, stirring for 30min, recovering Ni²⁺Reacting to generate basic nickel carbonate; opening a No. 11 valve, starting a centrifugal machine to separate solid and liquid of the nickel-containing wastewater, recovering solid basic nickel carbonate, and enabling the liquid nickel-containing wastewater to flow into a secondary crystallization tank for later use;

rinsing the basic nickel carbonate, adding pure water for wetting, slowly adding glacial acetic acid with the mass fraction of 98%, and reacting under the condition of excessive basic nickel carbonate to generate a nickel acetate solution;

step five, modifying the hole sealing agent, namely titrating the concentration of the nickel acetate solution and adding triethanolamine and isobutanol according to the medium-temperature hole sealing control index to form the hole sealing agent which can be directly added into the 16# medium-temperature hole sealing groove.

6. The method for recovering the system for coloring the mono-nickel salt and sealing the hole with the medium temperature in the aluminum processing according to claim 5, wherein in the fifth step, the concentration ratio of the nickel acetate solution to the triethanolamine is 10:1, and the concentration ratio of the nickel acetate solution to the isobutanol is 10: 1.

7. The method for recovering the mono-nickel salt coloring and medium-temperature hole sealing agent in the aluminum processing according to claim 5, wherein the third step further comprises the steps of wastewater recovery treatment and secondary crystallization:

opening a 12# valve, a 13# valve or a 14# valve, starting a 2# pump, opening a 17# valve, closing a 15# valve and a 16# valve, and pumping the nickel-free supernatant in the secondary crystallization tank into a wastewater treatment center for neutralization treatment; closing the 12# valve or the 13# valve or the 14# valve, closing the 17# valve, opening the 15# valve and the 16# valve, opening the 2# electric stirring, and pumping the secondary crystal at the bottom of the secondary crystallization tank into the recovery tank for secondary recovery of the basic nickel carbonate.

8. The method for recovering the system for coloring the mono-nickel salt and the medium-temperature hole sealing agent in the aluminum processing according to claim 5, wherein in the fourth step, the pH value of the generated nickel acetate solution is more than 6.

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