CN110818157A

CN110818157A - Treatment method for recycling waste acid of aluminum profile chemical polishing tank

Info

Publication number: CN110818157A
Application number: CN201810902786.4A
Authority: CN
Inventors: 吴正奇; 吴龙; 李倩; 陈小强
Original assignee: Hubei University of Technology
Current assignee: Hubei University of Technology
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2020-02-21
Anticipated expiration: 2038-08-09
Also published as: CN110818157B

Abstract

The invention discloses a method for treating waste acid of an aluminum profile chemical polishing tank for recycling, which comprises the steps of ⑴ diluting with water, putting the waste acid of the aluminum profile chemical polishing tank into a strong acid resistant container, adding pure water under stirring to obtain waste acid diluent, ⑵ performing membrane separation, performing solid-liquid separation on the waste acid diluent by using microporous membrane equipment, ⑶ performing heating reaction, putting membrane permeation liquid of the waste acid diluent into a reaction kettle, starting cold water to reflux, and stirring to obtain reaction liquid, ⑷ performing seed crystal induction, using crushed and screened added aluminum phosphate seed crystal to induce aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, ⑸ performing membrane separation, performing solid-liquid separation on the obtained aluminum phosphate precipitate by using the microporous membrane equipment, ⑹ concentrating and component adjusting.

Description

Treatment method for recycling waste acid of aluminum profile chemical polishing tank

Technical Field

The invention belongs to the technical field of aluminum profile processing, and particularly relates to a treatment method for recycling waste acid of an aluminum profile chemical polishing tank. The method is suitable for the treatment of the aluminum profile chemical polishing tank waste acid with any formula in the aluminum profile processing industry in a recycling manner, the treatment of the aluminum profile electrolytic polishing tank waste acid in the aluminum profile processing industry in a recycling manner and the treatment of the aluminum-containing waste acid in the aluminum profile processing industry in a recycling manner.

Background

Polishing the aluminum profile, and aims to enable the aluminum profile to generate a bright surface. There are chemical polishing and electrolytic polishing according to the polishing process. Because of low cost and simple process of chemical polishing, the prior aluminum profile polishing mainly adopts chemical polishing, and the electrolytic polishing only uses aluminum profiles with special purposes.

Chemical polishing was invented in the late 1940 s, when Henley was used for phosphoric acid-sulfuric acid type electrolytic polishing tests, when no electricity was supplied, corrosion of aluminum pieces was found to have a bright effect, and then he carefully studied the phenomenon to obtain the earliest chemical polishing process, wherein acid liquor ratio is 75% (volume fraction) of phosphoric acid and 25% (volume fraction) of sulfuric acid, and operating temperature is 90-100 ℃. Later, it was found that a particularly shiny effect could be obtained by adding 10% nitric acid to the above process, and chemical polishing was applied in industry, and corresponding patents were successively published. Bright anodic oxidation stably enters the market, and replaces a part of nickel-chromium plating process on steel or copper.

The chemical polishing does not need to be electrified or a special clamp, the operation is simple, but good heating and ventilation equipment is needed, the effect of 100 percent of reflectivity can be obtained by using high-purity aluminum, and the decorative glossiness can be achieved by using common aluminum alloy. Since chemical polishing is less costly than electropolishing, most bright anodization is accomplished using chemical polishing. The most common chemical polishing process comprises 75 percent (volume fraction) of phosphoric acid, 15 percent (volume fraction) of nitric acid and 10 percent (volume fraction) of sulfuric acid, wherein the operation temperature is 90-110 ℃, and the time is 0.5-3 min. Some processes only use phosphoric acid and nitric acid, and some add acetic acid, chromic acid or hydrofluoric acid. The polishing brightness can be increased by adding small amounts of cobalt salt, nickel salt and copper salt. The biggest disadvantage of chemical polishing is that the method can produce NOx toxic gas, and the yellow NOx gas is a strong carcinogen and is 'yellow dragon' which is difficult to volatilize in a chemical polishing workshop. People adopt a plurality of methods to solve the technical problem, and Japanese Tajima adopts a cage-shaped compound to absorb toxic gas to obtain a novel yellow-smoke-free chemical polishing process; in Germany, 16 percent (volume fraction) of ammonium bifluoride, 13 percent (volume fraction) of nitric acid and 25g/L of dextrin are adopted for aluminum parts with the purity of 99.99 percent, the operation temperature is low, and the gas evolution is little. Kaiser aluminum and chemicals company invented a similar process (volume fraction) of 2.5% nitric acid, 0.60% ammonium bifluoride, 0.6% chromic acid, 0.6% glycerol, 0.05% copper nitrate. Organic sulfide is also added in the phosphoric acid-sulfuric acid formula to replace nitric acid, so that the yellow-smoke-free polishing process is obtained.

In a word, the chemical polishing process widely adopted in the aluminum profile industry at present has the core and the main acid liquid components of phosphoric acid, sulfuric acid and nitric acid in sequence regardless of the chemical polishing acid liquid formula. In the chemical polishing process of the aluminum profile, acid liquor is placed in a polishing groove, the aluminum profile is in short-time contact with the acid liquor, and the aluminum profile generates a bright surface due to corrosion of the acid liquor.

As the aluminum profile is corroded by the acid liquor in the chemical polishing groove to generate a bright surface, aluminum on the surface part of the aluminum profile can form aluminum ions to be dissolved in the acid liquor, and meanwhile, the concentration of the acid liquor can be reduced due to the corrosion of the acid liquor and the aluminum profile. When the concentration of aluminum ions in the acid liquor of the chemical polishing tank rises to a certain value and the concentration of the acid liquor is reduced to a certain value, the polishing effect is seriously reduced, at the moment, the acid liquor of the chemical polishing tank needs to be replaced by the freshly prepared acid liquor, and the waste acid of the chemical polishing tank is generated. A medium-sized aluminum profile processing company produces about 6-15 tons of waste acid per day. Because the formula and the process of the chemical polishing tank acid liquor of each company are different, the composition of the chemical polishing tank waste acid is also different, but the basic composition of the chemical polishing tank waste acid is as follows: 40-60% of phosphoric acid (mass fraction), 20-40% of sulfuric acid (mass fraction), 8-20% of water (mass fraction), 2-6% of aluminum ions (mass fraction) and a small amount of other metal ions.

The waste acid of the aluminum profile chemical polishing tank has high viscosity, high concentration, high acidity, dirty appearance and toxic metal ions, so the treatment cost is extremely high, the treatment difficulty is extremely high, and a large amount of solid waste is produced to pollute the environment. An effective method for treating and utilizing waste acid of the aluminum profile chemical polishing tank is lacked at present. Therefore, the research on the treatment technology of the waste acid of the chemical polishing tank of the aluminum profile has important and practical social, economic and environmental significance for the aspects of clean production, environmental pollution reduction, economic benefit increase and the like in the aluminum profile industry.

Disclosure of Invention

Aiming at the defects of high treatment difficulty, serious waste pollution and the prior art of the waste acid of the aluminum profile chemical polishing tank, the invention aims to provide the treatment method for recycling the waste acid of the aluminum profile chemical polishing tank, which has the advantages of easy method, simple and convenient process, low cost, no pollution, sufficient aluminum ion removal, clear and transparent appearance, recyclable acid, high raw material utilization rate and capability of mechanically recycling the waste acid of the aluminum profile chemical polishing tank.

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

the technical concept of the invention is as follows: the method comprises the steps of utilizing the characteristic that water-insoluble components in the waste acid of the aluminum profile chemical polishing tank can be separated by a membrane and the property that phosphoric acid reacts with aluminum ions to generate water-insoluble aluminum phosphate, diluting the waste acid of the aluminum profile chemical polishing tank with water and performing membrane separation to obtain membrane permeation liquid diluted by the waste acid, performing reflux heating reaction to generate aluminum phosphate, adding aluminum phosphate seed crystals, inducing the aluminum phosphate generated by the reaction to form water-insoluble aluminum phosphate crystals, performing membrane separation to obtain the waste acid diluent without the aluminum ions after the aluminum phosphate crystals are crystallized, and performing heating concentration and component adjustment to obtain the recyclable acid liquor of the aluminum profile chemical polishing tank.

A treatment method for recycling waste acid from a chemical polishing tank of an aluminum profile is characterized by comprising the following steps:

⑴, adding water for dilution, namely putting the waste acid of the aluminum profile chemical polishing tank into a strong acid resistant container, adding pure water with the mass 1.0-5.0 times of that of the waste acid of the aluminum profile chemical polishing tank under the stirring condition, diluting the waste acid of the aluminum profile chemical polishing tank with high concentration, high viscosity and turbid appearance, continuously stirring for 0.5-5 hours to obtain waste acid diluent for later use, and controlling the stirring speed to be 10-300 rpm in the whole process of the step.

The waste acid of the aluminum profile chemical polishing tank is the acid liquor which is remained, can not be reused and needs to be abandoned after the aluminum profile is chemically polished in the polishing tank by the mixed acid liquor used for the chemical polishing of the aluminum profile, and comprises the following main components: 40-60% of phosphoric acid (mass fraction), 20-40% of sulfuric acid (mass fraction), 2-6% of aluminum ions (mass fraction) and 8-20% of water (mass fraction); the pure water refers to reverse osmosis pure water, ion exchange pure water and distillation condensation pure water with the conductivity lower than 10-3 s/m.

Preferably, the waste acid of the aluminum profile chemical polishing tank is acid liquor which is remained, cannot be reused and needs to be discarded after the aluminum profile chemical polishing is carried out on the aluminum profile by using mixed acid liquor for aluminum profile chemical polishing in the polishing tank, and the main components of the waste acid are as follows: 45-55% of phosphoric acid (mass fraction), 25-35% of sulfuric acid (mass fraction), 3-5% of aluminum ions (mass fraction) and 10-15% of water (mass fraction); the pure water refers to the conductivity of less than 5 x 10^-4s/m reverse osmosis pure water.

⑵, membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 5-70 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment to separate out insoluble solids so as to obtain membrane permeate of the waste acid diluent for later use.

The membrane material of the microporous membrane equipment is silicon carbide, the membrane component is a honeycomb briquette type inner tubular membrane, and the sizes of membrane pores are 1, 0.5, 0.1 and 0.04 mu m.

Preferably, the membrane material of the microporous membrane equipment is silicon carbide, the membrane component is in the form of a honeycomb briquette type inner tubular membrane, and the membrane pore size is 0.1 and 0.04 mu m.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a reaction kettle or other container, starting cold water for reflux, heating the membrane permeation liquid to the phosphoric acid dissociation reaction temperature and maintaining the phosphoric acid dissociation reaction temperature under the condition of continuous stirring, continuously heating and stirring for reacting for 1.0-15 hours to enable phosphoric acid and aluminum ions in the membrane permeation liquid to react to generate aluminum phosphate, and obtaining reaction liquid for later use, wherein the stirring speed in the step is controlled to be 10-300 rpm.

The temperature of the phosphoric acid dissociation reaction is the temperature capable of promoting the generation of the aluminum phosphate, and the range of the temperature is 35-120 ℃.

Preferably, the temperature of the dissociation reaction of the phosphoric acid is the temperature capable of promoting the generation of the aluminum phosphate, and the range of the dissociation reaction temperature of the phosphoric acid is 60-110 ℃.

⑷, inducing crystal seeds, namely taking solid aluminum phosphate, crushing the solid aluminum phosphate by using a stainless steel crusher, and sieving a crushed product by using a standard sieve to obtain aluminum phosphate crystal seeds, adding aluminum phosphate crystal seeds with the mass fraction of 0.05-5% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the condition of continuous stirring, closing and heating the mixture to naturally cool the mixture to 0-35 ℃, and continuing stirring for 1.0-25 hours to ensure that aluminum phosphate in the aluminum phosphate crystal seed induction reaction liquid fully forms aluminum phosphate precipitates to obtain reaction liquid of the aluminum phosphate precipitates, and controlling the stirring speed in the step to be 100-400 rpm.

The solid aluminum phosphate is analytically pure or chemically pure aluminum phosphate crystals without crystal water or with crystal water; and sieving by using a standard sieve, wherein the size of the standard sieve is 40-600 meshes.

Preferably, the solid aluminum phosphate is analytically pure aluminum phosphate crystals free of crystal water; and sieving the mixture by using a standard sieve, wherein the size of the standard sieve is 80-400 meshes.

⑸, membrane separation, namely controlling the temperature of the reaction liquid precipitated from the aluminum phosphate precipitate obtained in the step ⑷ to be 5-70 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment, and separating out insoluble aluminum phosphate precipitate to obtain the dealumination waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by a heating concentration method until the mass percentage of water content is 10-15% to obtain dealuminized acid liquid of the aluminum profile chemical polishing groove, analyzing and measuring the content of phosphoric acid and sulfuric acid in the dealuminized waste acid diluent, supplementing corresponding acid liquid according to the mass percentage of each acid liquid in the acid liquid of the aluminum profile chemical polishing groove required by a chemical polishing process to obtain recyclable acid liquid of the chemical polishing groove, using the recyclable acid liquid of the chemical polishing groove for chemical polishing of the aluminum profile of the next batch, and controlling the temperature of the material in the whole process of the step to be 20-110.

The heating concentration method is a forced circulation vacuum concentration method or a rising-falling film concentration method.

Preferably, the heating concentration method is a forced circulation vacuum concentration method.

Through the technical measures of the six steps, the most important is membrane separation of step ⑵, heating reaction of step ⑶ and seed crystal induction of step ⑷, the filtration of insoluble impurities in the dealuminized waste acid of the aluminum profile chemical polishing tank with high concentration and high viscosity is mainly solved through the filtration of a strong corrosion resistant silicon carbide membrane, the filtration of insoluble impurities in the dealuminized waste acid of the aluminum profile chemical polishing tank with high concentration and high viscosity is solved through the heating reaction of controlling the temperature, the dissociation of phosphoric acid is solved, aluminum phosphate is generated, and the crystallization of the aluminum phosphate is induced by using an aluminum phosphate seed crystal, so that the technical problems and difficulties of solid phase precipitation and the like of the aluminum phosphate are solved.

Through the technical treatment of the invention, the removal rate of insoluble impurities in the waste acid of the aluminum profile chemical polishing tank is 100%, and the appearance is clear and transparent; the retention rate of the sulfuric acid is 100 percent; the removal rate of aluminum ions is more than 99.9 percent; the phosphoric acid retention rate is 75-85% (the loss of phosphoric acid generates aluminum phosphate). The chemical polishing tank acid liquor obtained by adjusting the components of the treated aluminum profile chemical polishing tank dealumination acid liquor can be completely used for chemical polishing of the aluminum profile of the next batch.

Compared with the prior art, the method has the advantages and beneficial effects that:

low cost, no pollution, sufficient removal of aluminum ions, clear and transparent appearance, recyclable acid, high utilization rate of raw materials, simple and convenient process, capability of mechanical treatment and suitability for large-scale and small-scale production.

Aiming at the defects of high treatment difficulty, serious waste pollution and the prior art of the waste acid of the chemical polishing tank for the aluminum profile at present, the invention aims to provide the treatment method for recycling the waste acid of the chemical polishing tank for the aluminum profile, which has the advantages of low cost, no pollution, recyclable acid, high raw material utilization rate, simple and convenient process and mechanization.

The recyclable waste acid of the aluminum profile chemical polishing tank, which is treated by the method, is colorless to blue-green uniform liquid, aluminum ions influencing the chemical polishing effect are removed, turbidity is sufficient, phosphoric acid, sulfuric acid and other acid liquor are reserved, the recycling effect is the same as that of freshly prepared chemical polishing acid liquor, and strong environmental pollution, high treatment cost and waste of useful resources of the waste acid are avoided.

Drawings

FIG. 1 is a process flow diagram of a treatment method for recycling waste acid from a chemical polishing tank for aluminum profiles.

Detailed Description

The applicant shall now describe the process of the present invention in further detail with reference to specific examples.

Example 1:

a treatment method for recycling waste acid of an aluminum profile chemical polishing tank comprises the following steps:

⑴, adding water for dilution, namely taking 1000 g of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 50 percent (mass fraction) of phosphoric acid, 30 percent (mass fraction) of sulfuric acid, 13 percent (mass fraction) of water, 4 percent (mass fraction) of aluminum ions and 3 percent (mass fraction) of insoluble impurities, in a beaker, adding 1000 g of reverse osmosis pure water under the stirring condition of the stirring speed of 100rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 1.5 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 25 percent (mass fraction) of phosphoric acid, 15 percent (mass fraction) of sulfuric acid, 56.5 percent (mass fraction) of water, 2 percent (mass fraction) of aluminum ions and 1.5 percent (mass fraction) of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 25 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.04 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated out, and 1950 g of membrane permeation liquid of the waste acid diluent is obtained for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 95 ℃ and maintaining the temperature at 95 ℃ under the stirring condition that the stirring speed is 80rpm, and continuing heating, stirring and reacting for 8 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 200-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.5% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 150rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 10 ℃, and continuing stirring the mixture for 10 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 10 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 1770 g of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 80 ℃ and the vacuum degree is 0.095MPa until the mass percentage of water content is 13 percent to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 36.0 percent of phosphoric acid (mass fraction), 50.99 percent of sulfuric acid (mass fraction), 13 percent of water (mass fraction) and 0.01 percent of aluminum ions (mass fraction), and adding 85 percent of phosphoric acid and 98 percent of sulfuric acid according to calculation to ensure that the relative content of phosphoric acid is 73 percent (mass fraction) and the content of sulfuric acid is 27 percent (mass fraction) to obtain the recyclable chemical polishing groove acid liquid for chemical polishing of the aluminum profiles of the next batch.

By determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 72 percent (28 percent of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100 percent, the aluminum ion removal rate is 99.9 percent, the insoluble impurity removal rate is 100 percent, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 2:

⑴ diluting with water, namely taking 2.5 kg of aluminum profile chemical polishing tank waste acid mainly comprising 65 percent (mass fraction) of phosphoric acid, 15 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of water, 4.5 percent (mass fraction) of aluminum ions, 0.2 percent (mass fraction) of copper ions and 0.3 percent (mass fraction) of insoluble impurities into a beaker, adding 2.5 kg of reverse osmosis pure water under the stirring condition of the stirring speed of 100rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 2 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 32.5 percent (mass fraction) of phosphoric acid, 7.5 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of water, 2.25 percent (mass fraction) of aluminum ions, 0.1 percent (mass fraction) of copper ions and 0.15 percent (mass fraction) of insoluble impurities.

⑵ and (3) membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 5 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, so as to separate out insoluble solids, and obtain 4.95 kg of membrane permeate of the waste acid diluent for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 90 ℃ and maintaining the temperature of the membrane permeation liquid at 90 ℃ under the stirring condition that the stirring speed is 70rpm, and continuing heating, stirring and reacting for 10 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining a reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 300-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.3% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 150rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 5 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 4.81 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.09MPa to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 48.75 percent by mass of phosphoric acid, 36.04 percent by mass of sulfuric acid, 15 percent by mass of water, 0.01 percent by mass of aluminum ions and 0.2 percent by mass of copper ions, and supplementing 85 percent of phosphoric acid, 98 percent of sulfuric acid and 66 percent of nitric acid according to calculation to ensure that the relative content of phosphoric acid is 65 percent by mass, the relative content of nitric acid is 14 percent by mass and the relative content of sulfuric acid is 11 percent by mass, so as to obtain the recyclable chemical polishing groove acid liquid for the chemical polishing of the aluminum profile of the next batch.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 75% (25% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 3:

⑴ diluting with water, namely taking 6000 kg of aluminum profile chemical polishing tank waste acid mainly comprising 55 mass percent of phosphoric acid, 25 mass percent of sulfuric acid, 14.5 mass percent of water, 5 mass percent of aluminum ions and 0.5 mass percent of insoluble impurities into a reaction kettle, adding 6000 kg of reverse osmosis pure water under the stirring condition of 100rpm, diluting waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 2.5 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 27.5 mass percent of phosphoric acid, 12.5 mass percent of sulfuric acid, 57.25 mass percent of water, 2.5 mass percent of aluminum ions and 0.25 mass percent of insoluble impurities.

⑵ and (3) membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 5 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, so as to separate out insoluble solids, thereby obtaining 11950 kg of membrane permeation liquid of the waste acid diluent for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 100 ℃ and maintaining the temperature at 100 ℃ under the stirring condition that the stirring speed is 100rpm, and continuing heating, stirring and reacting for 9 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 400-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.2% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 150rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 5 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 11410 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely, concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step ⑸ by a forced circulation vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.097MPa until the mass percentage of water content is 14.5 percent, so as to obtain the dealuminized acid liquid of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquid mainly comprises 37.4 percent of phosphoric acid (mass fraction), 48.09 percent of sulfuric acid (mass fraction), 14.5 percent of water (mass fraction) and 0.01 percent of aluminum ions (mass fraction), and supplementing 85 percent of phosphoric acid and 98 percent of sulfuric acid according to calculation so that the relative content of phosphoric acid is 72 percent (mass fraction) and the relative content of sulfuric acid is 27 percent (mass fraction), so as to obtain the recyclable chemical polishing tank acid liquid for chemical polishing of the aluminum profiles of the next batch.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 68% (32% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 4:

⑴ diluting with water, namely taking 5.35 kg of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 65 percent (mass fraction) of phosphoric acid, 15 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of water, 3.5 percent (mass fraction) of aluminum ions, 0.2 percent (mass fraction) of copper ions and 1.3 percent (mass fraction) of insoluble impurities, in a glass container, adding 7 kg of reverse osmosis pure water under the stirring condition of the stirring speed of 90rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 2 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 28.2 percent (mass fraction) of phosphoric acid, 6.5 percent (mass fraction) of sulfuric acid, 63.2 percent (mass fraction) of water, 1.51 percent (mass fraction) of aluminum ions, 0.09 percent (mass fraction) of copper ions and 0.59 percent (mass fraction) of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 10 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.04 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated, and 12.2 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

⑶ heating reaction, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 85 ℃ and maintaining the temperature at 85 ℃ under the stirring condition that the stirring speed is 75rpm, and continuing heating, stirring and reacting for 16 hours to enable the phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, sieving the crushed product by using a 120-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.2% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 140rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 10 ℃, and continuing stirring for 16 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 10 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 11.4 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 80 ℃ and the vacuum degree is 0.095MPa until the mass percentage of moisture is 14 percent, and obtaining the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 52.65 percent of phosphoric acid (mass fraction), 33.12 percent of sulfuric acid (mass fraction), 14 percent of moisture (mass fraction), 0.01 percent of aluminum ions (mass fraction) and 0.22 percent of copper ions (mass fraction), and 85 percent of phosphoric acid, 98 percent of sulfuric acid and 66 percent of nitric acid are supplemented according to calculation, so that the relative content of phosphoric acid is 65 percent (mass fraction), the relative content of nitric acid is 14 percent (mass fraction) and the relative content of sulfuric acid is 11 percent (mass fraction), and the recyclable chemical polishing groove acid liquid is obtained and is used for chemical polishing of.

According to the determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 81 percent (19 percent of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100 percent, the aluminum ion removal rate is 99.9 percent, the insoluble impurity removal rate is 100 percent, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 5:

⑴ diluting with water, namely taking 7.23 kg of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 51 percent (mass fraction) of phosphoric acid, 29 percent (mass fraction) of sulfuric acid, 13 percent (mass fraction) of water, 3 percent (mass fraction) of aluminum ions and 4 percent (mass fraction) of insoluble impurities, in a glass container, adding 7.23 kg of reverse osmosis pure water under the stirring condition of the stirring speed of 120rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 1.5 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 25.5 percent (mass fraction) of phosphoric acid, 14.5 percent (mass fraction) of sulfuric acid, 56.5 percent (mass fraction) of water, 1.5 percent (mass fraction) of aluminum ions and 2 percent (mass fraction) of insoluble impurities.

⑵ and (3) membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 15 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, so as to separate out insoluble solids, thereby obtaining 14.4 kg of membrane permeate of the waste acid diluent for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 90 ℃ and maintaining the temperature of the membrane permeation liquid at 90 ℃ under the stirring condition that the stirring speed is 95rpm, and continuing heating, stirring and reacting for 12 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining a reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 100-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.35% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 150rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 15 ℃, and continuing stirring for 16 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 15 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 13.7 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 80 ℃ and the vacuum degree is 0.095MPa until the mass percentage of water content is 13 percent to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 41.82 percent of phosphoric acid (mass fraction), 45.17 percent of sulfuric acid (mass fraction), 13 percent of water (mass fraction) and 0.01 percent of aluminum ions (mass fraction), and adding 85 percent of phosphoric acid and 98 percent of sulfuric acid according to calculation to ensure that the relative content of phosphoric acid is 73 percent (mass fraction) and the content of sulfuric acid is 27 percent (mass fraction) to obtain the recyclable chemical polishing groove acid liquid for chemical polishing of the aluminum profiles of the next batch.

According to the determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 82% (19% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 6:

⑴ diluting with water, namely taking 1.56 kg of aluminum profile chemical polishing tank waste acid which mainly comprises 64 percent (mass fraction) of phosphoric acid, 16 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of water, 3.8 percent (mass fraction) of aluminum ions, 0.3 percent (mass fraction) of copper ions and 0.9 percent (mass fraction) of insoluble impurities, adding 1.56 g of reverse osmosis pure water under the stirring condition of the stirring speed of 95rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 1 hour to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 32 percent (mass fraction) of phosphoric acid, 8 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of water, 1.9 percent (mass fraction) of aluminum ions, 0.15 percent (mass fraction) of copper ions and 0.45 percent (mass fraction) of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 20 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.04 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated, and 3.06 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 95 ℃ and maintaining the temperature at 95 ℃ under the stirring condition that the stirring speed is 95rpm, and continuing heating, stirring and reacting for 13 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 200-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.25% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 200rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 20 ℃, and continuing stirring for 13 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 20 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.01 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 2.9 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 75 ℃ and the vacuum degree is 0.097MPa until the mass percentage of water content is 15 percent, and obtaining the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 50.56 percent of phosphoric acid (mass fraction), 34.43 percent of sulfuric acid (mass fraction), 15 percent of water (mass fraction), 0.01 percent of aluminum ions (mass fraction) and 0.35 percent of copper ions (mass fraction), and 85 percent of phosphoric acid, 98 percent of sulfuric acid and 66 percent of nitric acid are supplemented according to calculation, so that the relative content of phosphoric acid is 65 percent (mass fraction), the relative content of nitric acid is 14 percent (mass fraction) and the relative content of sulfuric acid is 11 percent (mass fraction), and the recyclable chemical polishing groove acid liquid is obtained and is used for chemical polishing.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 79% (21% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 7:

⑴ is diluted by adding water, namely, 9.6 kg of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 53 percent (mass fraction) of phosphoric acid, 27 percent (mass fraction) of sulfuric acid, 13 percent (mass fraction) of water, 2.8 percent (mass fraction) of aluminum ions and 4.2 percent (mass fraction) of insoluble impurities, is put into a glass container, 9.6 kg of reverse osmosis pure water is added under the stirring condition of the stirring speed of 95rpm, the waste acid with high concentration, high viscosity and turbid appearance is diluted, and the stirring is continued for 1 hour to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 26.5 percent (mass fraction) of phosphoric acid, 13.5 percent (mass fraction) of sulfuric acid, 56.5 percent (mass fraction) of water, 1.4 percent (mass fraction) of aluminum ions and 2.1 percent (mass fraction) of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 10 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.04 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated, and 19.15 kg of membrane permeate of the waste acid diluent is obtained for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 90 ℃ and maintaining the temperature of the membrane permeation liquid at 90 ℃ under the stirring condition that the stirring speed is 95rpm, and continuing heating, stirring and reacting for 14 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining a reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 160-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.7% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 190rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 10 ℃, and continuing stirring for 18 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 10 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 18.5 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 70 ℃ and the vacuum degree is 0.098MPa until the mass percentage of water content is 13 percent to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 42.93 percent (mass fraction), 44.06 percent (mass fraction), 13 percent (mass fraction) and 0.01 percent (mass fraction) of aluminum ions, and adding 85 percent of phosphoric acid and 98 percent of sulfuric acid according to calculation to ensure that the relative content of phosphoric acid is 73 percent (mass fraction) and the content of sulfuric acid is 27 percent (mass fraction) to obtain the recyclable chemical polishing groove acid liquid for chemical polishing of the aluminum profile of the next batch.

Example 8:

⑴ diluting with water, namely taking 3.75 kg of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 63 percent (mass fraction) of phosphoric acid, 17 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of water, 4.2 percent (mass fraction) of aluminum ions, 0.28 percent (mass fraction) of copper ions and 0.52 percent (mass fraction) of insoluble impurities, in a glass container, adding 3.75 g of reverse osmosis pure water under the stirring condition of the stirring speed of 95rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 1.5 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 31.5 percent (mass fraction) of phosphoric acid, 8.5 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of water, 2.1 percent (mass fraction) of aluminum ions, 0.14 percent (mass fraction) of copper ions and 0.52 percent (mass fraction) of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 30 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.1 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated, and 7.49 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 100 ℃ and maintaining the temperature at 100 ℃ under the stirring condition that the stirring speed is 70rpm, and continuing heating, stirring and reacting for 9 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 140-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.3% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 150rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 5 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 4700 g of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.09MPa to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 48.51 percent (mass fraction) of phosphoric acid, 36.28 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of moisture, 0.01 percent (mass fraction) of aluminum ions and 0.2 percent (mass fraction) of copper ions, and supplementing 85 percent of phosphoric acid, 98 percent of sulfuric acid and 66 percent of nitric acid according to calculation to ensure that the relative content of phosphoric acid is 65 percent (mass fraction), the relative content of nitric acid is 14 percent (mass fraction) and the relative content of sulfuric acid is 11 percent (mass fraction), so as to obtain the recyclable chemical polishing groove acid liquid for the chemical polishing of the aluminum profiles of the next batch.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 77% (23% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 9:

⑴ diluting with water, namely taking 55.6 kg of aluminum profile chemical polishing tank waste acid mainly comprising 55 mass percent of phosphoric acid, 25 mass percent of sulfuric acid, 13 mass percent of water, 3.4 mass percent of aluminum ions and 3.6 mass percent of insoluble impurities into a glass container, adding 55.6 kg of reverse osmosis pure water under the stirring condition of the stirring speed of 115rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 3 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 27.5 mass percent of phosphoric acid, 12.5 mass percent of sulfuric acid, 56.5 mass percent of water, 1.7 mass percent of aluminum ions and 1.8 mass percent of insoluble impurities.

⑵ membrane separation, wherein the temperature of the waste acid diluent obtained in the step ⑴ is controlled at 30 ℃, solid-liquid separation is carried out on the waste acid diluent by using microporous membrane equipment, the membrane material of which is silicon carbide, the membrane pores of which are 0.04 mu m and the membrane component of which is a honeycomb briquette type inner tubular membrane, insoluble solid is separated, and 11.1 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 105 ℃ and maintaining the temperature at 105 ℃ under the stirring condition that the stirring speed is 100rpm, and continuing heating, stirring and reacting for 9 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 300-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.19% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 250rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 30 ℃, and continuing stirring for 20 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 30 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 110.3 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by using a rotary vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.095MPa until the mass percentage of water content is 13 percent to obtain the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 42.9 percent of phosphoric acid (mass fraction), 44.09 percent of sulfuric acid (mass fraction), 13 percent of water (mass fraction) and 0.01 percent of aluminum ions (mass fraction), and supplementing 85 percent of phosphoric acid and 98 percent of sulfuric acid according to calculation to ensure that the relative content of phosphoric acid is 73 percent (mass fraction) and the content of sulfuric acid is 27 percent (mass fraction) to obtain the recyclable chemical polishing groove acid liquid for chemical polishing of the aluminum profiles of the next batch.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 78% (22% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

Example 10:

⑴ diluting with water, namely putting 71.5 kg of waste acid of the aluminum profile chemical polishing tank, which mainly comprises 65 percent (mass fraction) of phosphoric acid, 11 percent (mass fraction) of sulfuric acid, 15 percent (mass fraction) of water, 5.8 percent (mass fraction) of aluminum ions, 0.2 percent (mass fraction) of copper ions and 3 percent (mass fraction) of insoluble impurities, into a beaker, adding 71.5 kg of reverse osmosis pure water under the stirring condition of the stirring speed of 130rpm, diluting the waste acid with high concentration, high viscosity and turbid appearance, and continuously stirring for 4 hours to obtain waste acid diluent for later use, wherein the waste acid diluent comprises 32.5 percent (mass fraction) of phosphoric acid, 5.5 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of water, 2.9 percent (mass fraction) of aluminum ions, 0.1 percent (mass fraction) of copper ions and 1.5 percent (mass fraction) of insoluble impurities.

⑵ and (3) membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 25 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.04 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, so as to separate out insoluble solids, thereby obtaining 142.9 kg of membrane permeate of the waste acid diluent for later use.

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a heating reaction kettle, starting cold water for reflux, heating the membrane permeation liquid to 1100 ℃ and maintaining the temperature at 110 ℃ under the stirring condition that the stirring speed is 70rpm, and continuing heating, stirring and reacting for 15 hours to enable the phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, thus obtaining reaction liquid for later use.

⑷ seed crystal induction, namely, taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by a stainless steel crusher, sieving the crushed product by a 200-mesh standard sieve to obtain aluminum phosphate seed crystal, adding the aluminum phosphate seed crystal with the mass fraction of 0.6% of the reaction liquid into the reaction liquid obtained in the step ⑶ under the stirring condition that the stirring speed is 200rpm, closing and heating the reaction liquid to naturally cool the reaction liquid to 25 ℃, and continuing stirring for 19 hours to ensure that the aluminum phosphate in the aluminum phosphate seed crystal induction reaction liquid fully forms aluminum phosphate precipitate to obtain the reaction liquid separated out from the aluminum phosphate precipitate.

⑸ membrane separation, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitation obtained in the step ⑷ to be 25 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment of which the membrane material is silicon carbide, the membrane pores are 0.1 mu m and the membrane component is a honeycomb briquette type inner tubular membrane, separating out insoluble aluminum phosphate precipitate, and obtaining 141.6 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

⑹ concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by a forced circulation vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.09MPa until the mass percentage of water content is 15 percent, and obtaining the dealuminized acid liquid of the aluminum profile chemical polishing groove, wherein the dealuminized acid liquid mainly comprises 45.5 percent of phosphoric acid (mass fraction), 39.24 percent of sulfuric acid (mass fraction), 15 percent of water (mass fraction), 0.01 percent of aluminum ions (mass fraction) and 0.25 percent of copper ions (mass fraction), and 85 percent of phosphoric acid, 98 percent of sulfuric acid and 66 percent of nitric acid are supplemented according to calculation, so that the relative content of phosphoric acid is 65 percent (mass fraction), the relative content of nitric acid is 14 percent (mass fraction) and the relative content of sulfuric acid is 11 percent (mass fraction), and the recyclable chemical polishing groove acid liquid is obtained and is used for chemical polishing of.

Through determination, after the waste acid of the aluminum profile chemical polishing tank is treated by the method, the phosphoric acid retention rate is 70% (30% of phosphoric acid generates aluminum phosphate), the sulfuric acid retention rate is 100%, the aluminum ion removal rate is 99.9%, the insoluble impurity removal rate is 100%, and the appearance is clear and transparent. The chemical polishing groove acid liquor obtained after the aluminum section chemical polishing groove dealumination acid liquor is subjected to component adjustment can be completely used for chemical polishing of the aluminum sections of the next batch.

The specific embodiments described in this specification are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A treatment method for recycling waste acid of an aluminum profile chemical polishing tank is characterized by comprising the following steps: the method comprises the following steps:

⑴, adding water for dilution, namely putting the waste acid of the aluminum profile chemical polishing tank into a strong acid resistant container, adding pure water with the mass 1.0-5.0 times of that of the waste acid of the aluminum profile chemical polishing tank under the condition of stirring, diluting the waste acid of the aluminum profile chemical polishing tank with high concentration, high viscosity and turbid appearance, and continuously stirring for 0.5-5 hours to obtain waste acid diluent for later use;

⑵, membrane separation, namely controlling the temperature of the waste acid diluent obtained in the step ⑴ to be 5-70 ℃, and carrying out solid-liquid separation on the waste acid diluent by using microporous membrane equipment to separate out insoluble solids to obtain membrane permeate of the waste acid diluent for later use;

⑶, heating and reacting, namely putting the membrane permeation liquid of the waste acid diluent obtained in the step ⑵ into a reaction kettle or other container, starting cold water for refluxing, continuously stirring, heating to the phosphoric acid dissociation reaction temperature and maintaining the phosphoric acid dissociation reaction temperature, and continuously heating, stirring and reacting for 1.0-15 hours to enable phosphoric acid and aluminum ions in the membrane permeation liquid to react to generate aluminum phosphate, so as to obtain reaction liquid for later use;

⑷, inducing crystal seeds, namely taking solid aluminum phosphate, crushing the solid aluminum phosphate by using a stainless steel crusher, sieving the crushed product by using a standard sieve to obtain aluminum phosphate crystal seeds, continuously stirring the aluminum phosphate crystal seeds, adding the aluminum phosphate crystal seeds with the mass fraction of 0.05-5% of the reaction liquid into the reaction liquid obtained in the step ⑶, closing the heating to naturally cool the aluminum phosphate crystal seeds to 0-35 ℃, and continuously stirring the mixture for 1.0-25 hours to ensure that the aluminum phosphate in the aluminum phosphate crystal seed induction reaction liquid fully forms aluminum phosphate precipitates to obtain reaction liquid separated from the aluminum phosphate precipitates;

⑸, membrane separation, namely controlling the temperature of the reaction liquid precipitated by the aluminum phosphate precipitate obtained in the step ⑷ to be 5-70 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment, and separating out insoluble aluminum phosphate precipitate to obtain dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use;

⑹, concentration and component adjustment, namely concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing groove obtained in the step ⑸ by a heating concentration method until the mass percentage of water content is 10-15% to obtain a dealuminized acid solution of the aluminum profile chemical polishing groove, analyzing and measuring the content of phosphoric acid and sulfuric acid in the dealuminized acid solution, and supplementing the acid solution according to the mass percentage of each acid solution in the chemically polished acid solution of the aluminum profile chemical polishing groove to obtain the recycled chemical polishing groove acid solution.

2. The processing method for recycling the waste acid from the aluminum profile chemical polishing tank as claimed in claim 1, wherein the waste acid from the aluminum profile chemical polishing tank in the step ⑴ is an acid solution which is left after the aluminum profile chemical polishing by the mixed acid solution used for the aluminum profile chemical polishing in the polishing tank, cannot be reused and needs to be discarded, and comprises the main components of 40-60% by mass of phosphoric acid, 20-40% by mass of sulfuric acid, 2-6% by mass of aluminum ions and 8-20% by mass of water, and the pure water has an electrical conductivity of less than 10^-3s/m reverse osmosis process pure water, ion exchange process pure water, and distillation condensation process pure water.

3. The method for recycling waste acid from aluminum profile chemical polishing tanks, as recited in claim 1, wherein the microporous membrane device in steps ⑵ and ⑸, has a membrane material of silicon carbide, a membrane module of honeycomb briquette inner tubular membrane, and a membrane pore size of 1, 0.5, 0.1 and 0.04 μm.

4. The method for recycling waste acid from aluminum profile chemical polishing tanks, as recited in claim 1, wherein the temperature of the dissociation reaction of phosphoric acid in step ⑶ is 35-120 ℃ which can promote the generation of aluminum phosphate.

5. The method for recycling waste acid from the aluminum profile chemical polishing trough, as recited in claim 1, wherein the solid aluminum phosphate in step ⑷ is analytically pure or chemically pure crystal water-free or crystal water-containing aluminum phosphate crystals, and the standard screen is sieved with a standard sieve of 40-600 meshes.

6. The method for recycling waste acid from aluminum profile chemical polishing tanks, as recited in claim 1, wherein the heating concentration method in step ⑹ is a forced circulation vacuum concentration method or a rising-falling film concentration method.