CN110818157B

CN110818157B - Treatment method for recycling waste acid of aluminum profile chemical polishing tank

Info

Publication number: CN110818157B
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: 2022-03-29
Anticipated expiration: 2038-08-09
Also published as: CN110818157A

Abstract

The invention discloses a treatment method for recycling waste acid of an aluminum profile chemical polishing tank. The method comprises the following steps: firstly, adding water for dilution: taking waste acid of the aluminum profile chemical polishing tank in a strong acid resistant container, adding pure water under the stirring condition, and stirring to obtain waste acid diluent; the membrane separation is carried out: carrying out solid-liquid separation on the obtained waste acid diluent by using microporous membrane equipment; heating reaction: putting membrane permeation liquid of the waste acid diluent into a reaction kettle for heating reaction, starting cold water for refluxing, and stirring to obtain reaction liquid; fourth, seed crystal induction: aluminum phosphate in the crushed and sieved additional aluminum phosphate seed crystal induction reaction liquid is utilized to fully form aluminum phosphate precipitate; fifthly, membrane separation: carrying out solid-liquid separation on the reaction liquid precipitated from the aluminum phosphate precipitate by using microporous membrane equipment; sixthly, concentrating and adjusting components. The method is easy to implement, simple and convenient in process, low in cost, free of pollution, full in aluminum ion removal, clear and transparent in appearance, recyclable in acid, high in raw material utilization rate and capable of being mechanized.

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:

firstly, adding water for dilution: taking 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, and 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 5-70 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, insoluble solids are separated, and membrane permeation liquid of the waste acid diluent is obtained 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.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a reaction kettle or other containers, starting cold water 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 the membrane permeation liquid for reaction for 1.0 to 15 hours, reacting phosphoric acid and aluminum ions in the membrane permeation liquid to generate aluminum phosphate, and obtaining reaction liquid for later use. 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 ℃.

Fourth, seed crystal induction: taking solid aluminum phosphate, crushing the solid aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a standard sieve to obtain the aluminum phosphate seed crystal. And under the condition of continuously stirring, adding aluminum phosphate seed crystals with the mass fraction of 0.05-5% of the reaction liquid into the reaction liquid obtained in the step three, closing the heating and naturally cooling to 0-35 ℃, and continuously stirring for 1.0-25 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, so as to obtain the reaction liquid separated out from the aluminum phosphate precipitate. The stirring speed in the step is controlled 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.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated from the aluminum phosphate 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 the dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminizing waste acid diluent of the aluminum profile chemical polishing tank obtained in the step fifthly by using a heating concentration method until the mass percentage of water content is 10-15%, so as to obtain dealuminizing acid liquor of the aluminum profile chemical polishing tank; and analyzing and measuring the contents of phosphoric acid and sulfuric acid in the aluminum profile chemical polishing bath acid solution, and supplementing corresponding acid solution according to the requirement of the mass percentage content of each acid solution in the aluminum profile chemical polishing bath acid solution required by the chemical polishing process to obtain the recyclable chemical polishing bath acid solution for the chemical polishing of the aluminum profile of the next batch. The temperature of the materials in the whole process of the step is controlled 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 the steps of membrane separation, step three, heating reaction and step seed crystal induction, filtration of insoluble impurities in the dealuminizing waste acid of the aluminum profile chemical polishing tank with high concentration and high viscosity is mainly solved through filtration of the strong corrosion resistant silicon carbide film, the technical problems and difficulties such as solid phase precipitation of aluminum phosphate and the like are solved through the heating reaction for controlling the temperature and the dissociation of phosphoric acid for generating the aluminum phosphate and utilizing the aluminum phosphate seed crystal to induce the crystallization of the aluminum phosphate, the technical effects of completely separating the insoluble impurities in the dealuminizing waste acid of the aluminum profile chemical polishing tank, preventing the recycled aluminum ions in the dealuminizing waste acid of the aluminum profile chemical polishing tank and realizing the recycling of the dealuminizing waste acid of the aluminum profile chemical polishing tank through concentration and component adjustment are mainly achieved. Because the dealuminizing waste acid of the existing aluminum profile chemical polishing tank is directly used as waste and discharged after being neutralized by alkali, and almost no technical scheme exists, compared with the prior art, the invention has the advantages of innovation, resource utilization, environmental protection and the like.

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:

firstly, adding water for dilution: taking 1000 g of aluminum profile chemical polishing tank waste acid mainly comprising 50% of phosphoric acid (mass fraction), 30% of sulfuric acid (mass fraction), 13% of water (mass fraction), 4% of aluminum ions (mass fraction) and 3% of insoluble impurities (mass fraction), 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. The waste acid diluent consists of 25 percent (mass fraction) of phosphoric acid, 15 percent (mass fraction) of sulfuric acid, 56.5 percent (mass fraction) of moisture, 2 percent (mass fraction) of aluminum ions and 1.5 percent (mass fraction) of insoluble impurities.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 25 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, wherein the membrane material is silicon carbide, the membrane holes are 0.04 mu m, and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 1950 g of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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 continuously 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.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 200-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 150rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.5% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 10 ℃, and continuing stirring for 10 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated from the aluminum phosphate to be 10 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.04 mu m and a membrane component of a honeycomb briquette type inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 1770 g of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step to 13% by mass of moisture by using a rotary vacuum heating concentration method under the conditions that the temperature is 80 ℃ and the vacuum degree is 0.095MPa to obtain dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 36.0% of phosphoric acid (mass fraction), 50.99% of sulfuric acid (mass fraction), 13% of moisture (mass fraction) and 0.01% of aluminum ions (mass fraction); adding 85% of phosphoric acid and 98% of sulfuric acid according to the calculation, and enabling the relative content of the phosphoric acid to be 73% (mass fraction) and the content of the sulfuric acid to be 27% (mass fraction), so as to obtain the recyclable chemical polishing tank acid liquid for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: taking 2.5 kilograms of waste acid of the aluminum profile chemical polishing tank, the main components of which are 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, putting 2.5 kilograms of reverse osmosis pure water into the beaker under the stirring condition that the stirring speed is 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. The composition of the spent acid diluent is 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 5 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, wherein the membrane material is silicon carbide, the membrane holes are 0.1 mu m, and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solids are separated, and 4.95 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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, continuously heating, stirring and reacting for 10 hours, and reacting phosphoric acid and aluminum ions in the membrane permeation liquid to generate aluminum phosphate to obtain reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 300-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 150rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.3% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate to be 5 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.1 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 4.81 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step 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 dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized waste acid liquor mainly comprises 48.75% of phosphoric acid (mass fraction), 36.04% of sulfuric acid (mass fraction), 15% of water (mass fraction), 0.01% of aluminum ions (mass fraction) and 0.2% of copper ions (mass fraction); adding 85% of phosphoric acid, 98% of sulfuric acid and 66% of nitric acid according to the calculation, so that the relative content of phosphoric acid is 65% (mass fraction), the relative content of nitric acid is 14% (mass fraction) and the relative content of sulfuric acid is 11% (mass fraction), and obtaining the recyclable chemical polishing bath acid solution for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: 6000 kg of aluminum profile chemical polishing tank waste acid mainly comprising 55 percent (mass fraction) of phosphoric acid, 25 percent (mass fraction) of sulfuric acid, 14.5 percent (mass fraction) of water, 5 percent (mass fraction) of aluminum ions and 0.5 percent (mass fraction) of insoluble impurities is put into a reaction kettle, 6000 kg of reverse osmosis pure water is added under the stirring condition of the stirring speed of 100rpm, the waste acid with high concentration, high viscosity and turbid appearance is diluted, and the stirring is continued for 2.5 hours, so that waste acid diluent is obtained for later use. The composition of the spent acid diluent is 27.5 percent (mass fraction) of phosphoric acid, 12.5 percent (mass fraction) of sulfuric acid, 57.25 percent (mass fraction) of water, 2.5 percent (mass fraction) of aluminum ions and 0.25 percent (mass fraction) of insoluble impurities.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 5 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, wherein the membrane material is silicon carbide, the membrane holes are 0.04 mu m, and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solids are separated, and 11950 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to reflux, heating the membrane permeation liquid to 100 ℃ and maintaining the temperature at 100 ℃ under the stirring condition that the stirring speed is 100rpm, continuously 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, and obtaining reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 400-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 150rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.2% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated from the aluminum phosphate to be 5 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.04 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 11410 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step to moisture mass percent of 14.5% by using a forced circulation vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.097MPa to obtain the dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 37.4% (mass fraction) of phosphoric acid, 48.09% (mass fraction) of sulfuric acid, 14.5% (mass fraction) of moisture and 0.01% (mass fraction) of aluminum ions; adding 85% of phosphoric acid and 98% of sulfuric acid according to the calculation to ensure that the relative content of the phosphoric acid is 72% (mass fraction) and the relative content of the sulfuric acid is 27% (mass fraction), thus obtaining the recyclable chemical polishing bath acid solution which is used for 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 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:

firstly, adding water for dilution: taking 5.35 kg of waste acid of the aluminum profile chemical polishing tank, wherein the main components of the waste acid comprise 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, 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. The composition of the spent acid diluent is 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 10 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment of which the membrane material is silicon carbide, the membrane holes are 0.04 mu m and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 12.2 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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 continuously heating, stirring and reacting for 16 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.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 120-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 140rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.2% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 10 ℃, and continuously stirring for 16 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated and separated out from the aluminum phosphate to be 10 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.04 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 11.4 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step fifthly 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%, so as to obtain the dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 52.65% (mass fraction) of phosphoric acid, 33.12% (mass fraction) of sulfuric acid, 14% (mass fraction) of moisture, 0.01% (mass fraction) of aluminum ions and 0.22% (mass fraction) of copper ions; adding 85% of phosphoric acid, 98% of sulfuric acid and 66% of nitric acid according to the calculation, so that the relative content of phosphoric acid is 65% (mass fraction), the relative content of nitric acid is 14% (mass fraction) and the relative content of sulfuric acid is 11% (mass fraction), and obtaining the recyclable chemical polishing bath acid solution for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: taking 7.23 kg of aluminum profile chemical polishing tank waste acid mainly comprising 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 into 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. The composition of the spent acid diluent is 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 15 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, wherein the membrane material is silicon carbide, the membrane holes are 0.1 mu m, and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solids are separated, and 14.4 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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, continuously heating, stirring and reacting for 12 hours, and reacting phosphoric acid and aluminum ions in the membrane permeation liquid to generate aluminum phosphate to obtain reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 100-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 150rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.35% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 15 ℃, and continuously stirring for 16 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate to be 15 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.1 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 13.7 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step to 13% by mass of moisture by using a rotary vacuum heating concentration method under the conditions that the temperature is 80 ℃ and the vacuum degree is 0.095MPa to obtain dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 41.82% (mass fraction) of phosphoric acid, 45.17% (mass fraction) of sulfuric acid, 13% (mass fraction) of moisture and 0.01% (mass fraction) of aluminum ions; adding 85% of phosphoric acid and 98% of sulfuric acid according to the calculation, and enabling the relative content of the phosphoric acid to be 73% (mass fraction) and the content of the sulfuric acid to be 27% (mass fraction), so as to obtain the recyclable chemical polishing tank acid liquid for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: taking 1.56 kilograms of waste acid of an aluminum profile chemical polishing tank, 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 grams 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. The composition of the spent acid diluent is 32 percent (mass fraction) of phosphoric acid, 8 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of moisture, 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 20 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment of which the membrane material is silicon carbide, the membrane holes are 0.04 mu m and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 3.06 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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 continuously heating, stirring and reacting for 13 hours to enable phosphoric acid and aluminum ions in the membrane permeation liquid to react to generate aluminum phosphate, thus obtaining reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 200-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 200rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.25% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 20 ℃, and continuously stirring for 13 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated and separated out from the aluminum phosphate to be 20 ℃, carrying out solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.01 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 2.9 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step fifthly 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 moisture is 15%, so as to obtain the dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 50.56% (mass fraction) of phosphoric acid, 34.43% (mass fraction) of sulfuric acid, 15% (mass fraction) of moisture, 0.01% (mass fraction) of aluminum ions and 0.35% (mass fraction) of copper ions; adding 85% of phosphoric acid, 98% of sulfuric acid and 66% of nitric acid according to the calculation, so that the relative content of phosphoric acid is 65% (mass fraction), the relative content of nitric acid is 14% (mass fraction) and the relative content of sulfuric acid is 11% (mass fraction), and obtaining the recyclable chemical polishing bath acid solution for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: taking 9.6 kilograms of aluminum profile chemical polishing tank waste acid 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 into a glass container, adding 9.6 kilograms 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. The composition of the spent acid diluent is 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 10 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment of which the membrane material is silicon carbide, the membrane holes are 0.04 mu m and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 19.15 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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, continuously heating, stirring and reacting for 14 hours, and reacting phosphoric acid and aluminum ions in the membrane permeation liquid to generate aluminum phosphate to obtain reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 160-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 190rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.7% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 10 ℃, and continuously stirring for 18 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate to be 10 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.04 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 18.5 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step to 13% by mass of moisture by using a rotary vacuum heating concentration method under the conditions that the temperature is 70 ℃ and the vacuum degree is 0.098MPa to obtain dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 42.93% (mass fraction) of phosphoric acid, 44.06% (mass fraction) of sulfuric acid, 13% (mass fraction) of moisture and 0.01% (mass fraction) of aluminum ions; adding 85% of phosphoric acid and 98% of sulfuric acid according to the calculation, and enabling the relative content of the phosphoric acid to be 73% (mass fraction) and the content of the sulfuric acid to be 27% (mass fraction), so as to obtain the recyclable chemical polishing tank acid liquid for chemical polishing of the next batch of aluminum profiles.

Example 8:

firstly, adding water for dilution: taking 3.75 kilograms of waste acid of the aluminum profile chemical polishing tank, the main components of which are 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, adding 3.75 grams 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. The composition of the spent acid diluent is 31.5 percent (mass fraction) of phosphoric acid, 8.5 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of moisture, 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 30 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment of which the membrane material is silicon carbide, the membrane holes are 0.1 mu m and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 7.49 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to reflux, heating the membrane permeation liquid to 100 ℃ and maintaining the temperature at 100 ℃ under the stirring condition that the stirring speed is 70rpm, continuously 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, and obtaining reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 140-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 150rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.3% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 5 ℃, and continuing stirring for 15 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated and separated out from the aluminum phosphate to be 5 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.1 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 4700 g of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminizing waste acid diluent of the aluminum profile chemical polishing tank obtained in the step 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 dealuminizing acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminizing waste acid liquor mainly comprises 48.51% of phosphoric acid (mass fraction), 36.28% of sulfuric acid (mass fraction), 15% of water (mass fraction), 0.01% of aluminum ions (mass fraction) and 0.2% of copper ions (mass fraction); adding 85% of phosphoric acid, 98% of sulfuric acid and 66% of nitric acid according to the calculation, so that the relative content of phosphoric acid is 65% (mass fraction), the relative content of nitric acid is 14% (mass fraction) and the relative content of sulfuric acid is 11% (mass fraction), and obtaining the recyclable chemical polishing bath acid solution for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: 55.6 kg of aluminum profile chemical polishing tank waste acid mainly comprising 55 percent (mass fraction) of phosphoric acid, 25 percent (mass fraction) of sulfuric acid, 13 percent (mass fraction) of water, 3.4 percent (mass fraction) of aluminum ions and 3.6 percent (mass fraction) of insoluble impurities is put into a glass container, 55.6 kg of reverse osmosis pure water is added under the stirring condition of the stirring speed of 115rpm, the waste acid with high concentration, high viscosity and turbid appearance is diluted, and the stirring is continued for 3 hours, so that waste acid diluent is obtained for later use. The composition of the spent acid diluent is 27.5 percent (mass fraction) of phosphoric acid, 12.5 percent (mass fraction) of sulfuric acid, 56.5 percent (mass fraction) of water, 1.7 percent (mass fraction) of aluminum ions and 1.8 percent (mass fraction) of insoluble impurities.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 30 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment of which the membrane material is silicon carbide, the membrane holes are 0.04 mu m and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solid is separated, and 11.1 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to reflux, heating the membrane permeation liquid to 105 ℃ and maintaining the temperature at 105 ℃ under the stirring condition that the stirring speed is 100rpm, continuously 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, and obtaining reaction liquid for later use.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 300-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 250rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.19% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 30 ℃, and continuing stirring for 20 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated from the aluminum phosphate to be 30 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.04 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 110.3 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step to 13% by mass of moisture by using a rotary vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.095MPa to obtain dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized acid liquor mainly comprises 42.9% of phosphoric acid (mass fraction), 44.09% of sulfuric acid (mass fraction), 13% of moisture (mass fraction) and 0.01% of aluminum ions (mass fraction); adding 85% of phosphoric acid and 98% of sulfuric acid according to the calculation, and enabling the relative content of the phosphoric acid to be 73% (mass fraction) and the content of the sulfuric acid to be 27% (mass fraction), so as to obtain the recyclable chemical polishing tank acid liquid for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: 71.5 kg of waste acid of an aluminum profile chemical polishing tank, the main components of which are 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, is put into a beaker, 71.5 kg of reverse osmosis pure water is added under the stirring condition that the stirring speed is 130rpm, the waste acid with high concentration, high viscosity and turbid appearance is diluted, and the stirring is continued for 4 hours, so that waste acid diluent is obtained for later use. The composition of the spent acid diluent is 32.5 percent (mass fraction) of phosphoric acid, 5.5 percent (mass fraction) of sulfuric acid, 57.5 percent (mass fraction) of moisture, 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.

The membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 25 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, wherein the membrane material is silicon carbide, the membrane holes are 0.04 mu m, and the membrane component is a honeycomb briquette type inner tube type membrane, insoluble solids are separated, and 142.9 kg of membrane permeation liquid of the waste acid diluent is obtained for later use.

Heating reaction: and (3) putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a heating reaction kettle, starting cold water to 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 continuously heating, stirring and reacting for 15 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.

Fourth, seed crystal induction: taking analytically pure aluminum phosphate without crystal water, crushing the aluminum phosphate by using a stainless steel crusher, and sieving the crushed material by using a 200-mesh standard sieve to obtain aluminum phosphate seed crystals. And under the stirring condition that the stirring speed is 200rpm, adding aluminum phosphate seed crystals with the mass fraction of 0.6% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating and naturally cooling to 25 ℃, and continuously stirring for 19 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, thereby obtaining the reaction liquid separated out from the aluminum phosphate precipitate.

Fifthly, membrane separation: and step four, controlling the temperature of the reaction liquid precipitated by the aluminum phosphate to be 25 ℃, performing solid-liquid separation on the reaction liquid by using microporous membrane equipment with a membrane material of silicon carbide, a membrane hole of 0.1 mu m and a membrane component of a honeycomb briquette inner tubular membrane, and separating out insoluble aluminum phosphate precipitate to obtain 141.6 kg of dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use.

Sixthly, concentrating and adjusting components: concentrating the dealuminized waste acid diluent of the aluminum profile chemical polishing tank obtained in the step by using a forced circulation vacuum heating concentration method under the conditions that the temperature is 85 ℃ and the vacuum degree is 0.09MPa to obtain dealuminized acid liquor of the aluminum profile chemical polishing tank, wherein the dealuminized waste acid diluent mainly comprises 45.5% (mass fraction) of phosphoric acid, 39.24% (mass fraction) of sulfuric acid, 15% (mass fraction) of water, 0.01% (mass fraction) of aluminum ions and 0.25% (mass fraction) of copper ions; adding 85% of phosphoric acid, 98% of sulfuric acid and 66% of nitric acid according to the calculation, so that the relative content of phosphoric acid is 65% (mass fraction), the relative content of nitric acid is 14% (mass fraction) and the relative content of sulfuric acid is 11% (mass fraction), and obtaining the recyclable chemical polishing bath acid solution for chemical polishing of the next batch of aluminum profiles.

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:

firstly, adding water for dilution: taking 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, and continuously stirring for 0.5-5 hours to obtain waste acid diluent for later use;

the membrane separation is carried out: the temperature of the waste acid diluent is controlled to be 5-70 ℃, solid-liquid separation is carried out on the waste acid diluent by microporous membrane equipment, insoluble solids are separated, and membrane permeation liquid of the waste acid diluent is obtained for later use;

heating reaction: putting the membrane permeation liquid of the waste acid diluent obtained in the step II into a reaction kettle or other containers, starting cold water to reflux, continuously stirring, heating to the phosphoric acid dissociation reaction temperature, maintaining the phosphoric acid dissociation reaction temperature, continuously heating, stirring and reacting for 1.0-15 hours to enable phosphoric acid in the membrane permeation liquid to react with aluminum ions to generate aluminum phosphate, and obtaining reaction liquid for later use;

fourth, seed crystal induction: taking solid aluminum phosphate, crushing the solid aluminum phosphate by using a stainless steel crusher, sieving a crushed product by using a standard sieve to obtain aluminum phosphate seed crystals, continuously stirring, adding the aluminum phosphate seed crystals with the mass fraction of 0.05-5% of the reaction liquid into the reaction liquid obtained in the step III, closing the heating to naturally cool the reaction liquid to 0-35 ℃, and continuously stirring for 1.0-25 hours to ensure that the aluminum phosphate seed crystals induce the aluminum phosphate in the reaction liquid to fully form aluminum phosphate precipitate, so as to obtain reaction liquid separated out from the aluminum phosphate precipitate;

fifthly, membrane separation: controlling the temperature of the reaction liquid precipitated and separated out from the aluminum phosphate 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 a dealuminized waste acid diluent of the aluminum profile chemical polishing tank for later use;

sixthly, concentrating and adjusting components: concentrating the dealuminizing waste acid diluent of the aluminum profile chemical polishing tank obtained in the step fifthly by using a heating concentration method until the mass percentage of water content is 10-15%, so as to obtain dealuminizing acid liquor of the aluminum profile chemical polishing tank; analyzing and measuring the contents of phosphoric acid and sulfuric acid in the aluminum profile chemical polishing tank acid solution, and supplementing the acid solution according to the mass percentage content of each acid solution in the chemically polished aluminum profile chemical polishing tank acid solution to obtain the recycled chemical polishing tank acid solution;

the waste acid for the aluminum profile chemical polishing groove in the step is acid liquor which is remained, cannot be reused and needs to be abandoned after the aluminum profile is chemically polished in the polishing groove by mixed acid liquor for aluminum profile chemical polishing, and comprises the following main components: 40-60% of phosphoric acid, 20-40% of sulfuric acid, 2-6% of aluminum ions and 8-20% of water; the pure water refers to the conductivity of less than 10^-3s/m reverse osmosis method pure water, ion exchange method pure water and distillation condensation method pure water;

the microporous membrane equipment comprises a membrane material which is silicon carbide, a membrane component which is a honeycomb briquette type inner tubular membrane, and membrane pores of the microporous membrane equipment are 1, 0.5, 0.1 or 0.04 microns.

2. The treatment method for recycling waste acid from the aluminum profile chemical polishing tank, according to claim 1, is characterized in that: and the temperature of the phosphoric acid dissociation reaction in the step three is the temperature capable of promoting the generation of the aluminum phosphate, and the range of the temperature is 35-120 ℃.

3. The treatment method for recycling waste acid from the aluminum profile chemical polishing tank, according to claim 1, is characterized in that: and step four, the solid aluminum phosphate is one of an analytically pure aluminum phosphate crystal without crystal water, an analytically pure aluminum phosphate crystal with crystal water, a chemically pure aluminum phosphate crystal without crystal water and a chemically pure aluminum phosphate crystal with crystal water, and the solid aluminum phosphate is sieved by a standard sieve, wherein the size of the standard sieve is 40-600 meshes.

4. The treatment method for recycling waste acid from the aluminum profile chemical polishing tank, according to claim 1, is characterized in that: the heating concentration method in the step sixteenth is a forced circulation vacuum concentration method or a rising-falling film concentration method.