Recovery process of waste residues in steel ball series grinding process

Abstract

The invention discloses a recovery process of waste residues in a steel ball series grinding process, and relates to the field of waste residue recovery in the series grinding process. The process comprises the following steps: slurry preparation: adding water into waste residues for dilution to obtain slurry; the slurry is graded, and particles with the particle size smaller than 100 micrometers are screened out and serve as ferromagnetic powder for standby application; magnetic separation: diluting the graded slurry with water, feeding the diluted slurry into a magnetic separator for magnetic separation, and keeping the magnetically separated ferromagnetic powder for later use; acid leaching: carrying out solid-liquid separation on tail mud generated after magnetic separation of the slurry, soaking and cleaning a filter cake with a hydrochloric acid solution, stopping feeding when the pH value of the hydrochloric acid solution reaches 4-6, and then carrying out solid-liquid separation; and drying and screening: drying and screening the filter cake subjected to solid-liquid separation to obtain carborundum with different particle sizes. The ferromagnetic powder obtained through the technology can be mixed with white mud in proportion to serve as iron ore powder to be sold, and the carborundum can be returned to a series grinding procedure to be used after being reprocessed and can also be used for manufacturing refractory materials, building materials and ceramsite.

Description

Technical Field

[0001] The invention relates to the field of waste material recycling, and in particular to a process for recycling waste residue from a steel ball grinding process. Background Art

[0002] In the production process of ordinary precision small steel balls, the series grinding process is widely used to remove the oxide and fatigue layer on the surface of the steel ball, while reducing the surface roughness value. This process is still a key link in the production of ordinary precision small steel balls due to its simplicity, high efficiency and low cost.

[0003] The specific operation of the grinding process is: put the steel balls after polishing or heat treatment into the horizontal barrel, add appropriate amount of water and brown corundum (corundum) abrasive, and treat the surface of the steel balls through the grinding process. When the size and surface roughness of the steel balls meet the quality requirements, rinse with water to remove the ground brown corundum (corundum), ferromagnetic powder and iron powder on the surface. After rust prevention treatment, the rinsed steel balls enter the next process.

[0004] The wastewater generated during the milling process is generally recycled after sedimentation and filtration. However, the waste residue (called "black mud" in the industry) generated during the sedimentation and filtration process has not been effectively utilized due to its physical and chemical properties: Composition characteristics: Black mud mainly contains brown corundum (corundum) abrasive, iron powder, ferroferric oxide and ferric oxide. The iron content is usually below 35%, which is much lower than the iron content of the waste slag from the photocatalytic process (called "white mud" in the industry), and therefore has no direct economic value.

[0005] Physical properties: The particle size of black mud is mostly around 1200 mesh, which is soft soil similar to silt and cannot be used as infrastructure cushion or backfill material.

[0006] Disposal method: At present, a large amount of black mud in the steel ball industry is mainly dumped into abandoned mines, sand pits or large earth pits in rural areas, and only a small amount is used to make cement-filled bricks. This treatment method has great environmental and geological impact risks.

[0007] According to the calculation that about 25 kilograms of black mud is produced for every ton of steel balls produced, an industrial cluster with an annual output of 150,000 tons of ordinary precision steel balls will produce about 3,500 tons of black mud each year. If it is not effectively utilized, it will have a long-term negative impact on the local environment and waste potential resources.

[0008] Therefore, it can be seen that the prior art has the following defects: Waste of resources: Iron powder, ferroferric oxide and other components in black mud cannot be effectively recycled, resulting in waste of resources.

[0009] Environmental burden: A large amount of black mud is directly dumped, and long-term accumulation may have adverse effects on the land, water sources and ecological environment.

[0010] Low economic benefits: The current method of black mud disposal not only fails to create economic benefits, but also requires additional processing and transportation costs, further increasing the burden on enterprises. Summary of the invention

[0011] In response to the defects in the prior art, this application proposes an innovative black mud recovery and treatment method and system, aiming to achieve the following goals: efficiently recover the valuable components in the black mud, and treat the black mud in a scientific way to avoid its direct discharge to the environment, while reducing the long-term impact on the land and ecology, and using the recycled black mud resources to manufacture high value-added products, thereby reducing the production costs of enterprises and increasing the added value of the industrial chain.

[0012] The present invention solves the technical problem by adopting the following technical solutions.

[0013] A process for recovering waste residue from a steel ball grinding process comprises the following steps: Slurry preparation: adding waste residue to water for dilution to obtain slurry; Particle size classification: Classify the slurry and select particles with a size less than 100 microns as ferromagnetic powder for future use; Magnetic separation: After the classified slurry is diluted with water, it is sent to a magnetic separator for magnetic separation, and the ferromagnetic powder separated by magnetic separation is kept for later use; Acid leaching: The tailing mud produced after magnetic separation of the slurry is subjected to solid-liquid separation to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution, and the addition of the material is stopped when the pH value of the hydrochloric acid solution reaches 4-6; Drying and screening: The solid-liquid separation of the slurry after acid leaching is carried out to obtain a filter cake, and the filter cake is dried and screened to obtain corundum of different particle sizes.

[0014] Furthermore, the process also includes the following steps: Impurity removal: After adding hydrogen peroxide to the solution obtained by solid-liquid separation after acid leaching, sodium hydroxide is added to remove calcium chloride in the solution, so that the ferrous chloride in the solution is converted into ferric chloride through hydrogen peroxide, and then calcium hydroxide is reacted with calcium chloride in the solution to generate calcium hydroxide; To prepare ferric chloride, the impurity-removed solution is concentrated and crystallized through a drying crystallization system, which utilizes the property of reduced solubility of calcium hydroxide at high temperature to separate calcium hydroxide from the solution to obtain the finished ferric chloride.

[0015] Furthermore, in the preparation of slurry, the mass concentration of slurry is 5-20%. Since the minimum particle size of black mud is 5 microns and the maximum particle size is 0.43 mm (430 microns), those skilled in the art can adjust the mass concentration according to the ratio of fine particles and coarse particles in black mud. Generally, the more fine particles, the higher the mass concentration. The more coarse particles, the lower the mass concentration. After adjustment, the slurry can be driven to pass through the subsequent processes normally.

[0016] Furthermore, in the particle size classification, a hydraulic classifier or a screening or flotation method is used to classify the slurry.

[0017] Further, magnetic separation: the classified slurry is diluted with water to prepare a slurry with a mass concentration of 10-20%, and the diluted slurry is pumped into a magnetic separator for magnetic separation.

[0018] Furthermore, in the magnetic separation process, 0.5-1.5% additives are added to the diluted slurry and the slurry is stirred before being pumped into a magnetic separator for magnetic separation. The additive comprises one or two substances selected from sodium hexametaphosphate and water glass, so that the effect of magnetic separation can be further enhanced by the additives.

[0019] Furthermore, the mass concentration of the diluted slurry is 10-20%.

[0020] Preferably, in the magnetic separation process, the mass concentration of the diluted slurry is 13-17%.

[0021] Furthermore, in the magnetic separation process, the additive comprises sodium hexametaphosphate and water glass. In the additive, the proportion of sodium hexametaphosphate is 30-70%, and the proportion of water glass is 30-70%.

[0022] Furthermore, the additive is added in an amount of 0.8-1.2%, wherein the proportion of sodium hexametaphosphate in the additive is 45-55%, and the proportion of water glass is 45-55%. When in use, the diluted slurry is first added to sodium hexametaphosphate and stirred for more than 10 minutes, then water glass is added and stirred for more than 10 minutes, and then the stirred slurry is pumped into a magnetic separator for magnetic separation.

[0023] Preferably, the additive is added in an amount of 1%, wherein the proportion of sodium hexametaphosphate in the additive is 50%, and the proportion of water glass is 50%. When in use, the diluted slurry is first added to sodium hexametaphosphate and stirred for more than 20 minutes, then water glass is added and stirred for more than 20 minutes, and then the stirred slurry is pumped into a magnetic separator for magnetic separation.

[0024] Furthermore, in the acid leaching process: the tailing mud produced after the slurry is subjected to magnetic separation is subjected to solid-liquid separation to obtain a filter cake. The filter cake is soaked and cleaned with a hydrochloric acid solution with a pH of -1.5, and the addition of the material is stopped when the pH value of the hydrochloric acid solution reaches 4-6.

[0025] Technical effect: 1. This application can efficiently recover valuable components in black mud: through advanced separation and extraction technology, resources such as iron powder and ferroferric oxide in black mud can be efficiently recovered, providing the possibility for its use in metallurgy, building materials and other fields.

[0026] 2. Reduce environmental burden: Through scientific treatment of black mud, reduce its direct discharge to the environment and reduce the long-term impact on land and ecology.

[0027] 3. Improve economic benefits: Use recycled black mud resources to manufacture high value-added products, such as building material additives or new filling materials, thereby reducing the production costs of enterprises and increasing the added value of the industrial chain.

[0028] 4. Establish a sustainable development model: Introduce the concept of resource recycling in the steel ball production process, reduce the emission of industrial waste, and promote the green development of the industry. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further explained and illustrated by specific embodiments below.

[0030] Embodiment 1: A process for recovering waste residue from a steel ball grinding process, comprising the following steps: Slurry preparation: Add water to dilute the waste residue to obtain slurry, the mass concentration of the slurry is 5%.

[0031] Particle size classification: Use a hydraulic classifier to classify the slurry and screen out particles with a particle size of less than 100 microns as ferromagnetic powder for use; Magnetic separation: dilute the classified slurry with water to prepare a slurry with a concentration of 10%. First, add 0.4% sodium hexametaphosphate to the diluted slurry and stir for more than 20 minutes. Then add 0.6% water glass and mix. Then pump it into the magnetic separator for magnetic separation. The ferromagnetic powder separated by magnetic separation is set aside. Acid leaching: The tailing mud produced after magnetic separation of the slurry is subjected to solid-liquid separation to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution with a pH of -1.5, and the addition of material is stopped when the pH value of the hydrochloric acid solution reaches 4-6; Drying and screening: The slurry after acid leaching is separated into solid and liquid to obtain a filter cake, which is then dried and screened by a drum scraper dryer to obtain corundum of different particle sizes.

[0032] Impurity removal: After adding hydrogen peroxide to the solution obtained by solid-liquid separation after acid leaching, sodium hydroxide is added to remove calcium chloride in the solution, so that the ferrous chloride in the solution is converted into ferric chloride through hydrogen peroxide, and then calcium hydroxide is reacted with the calcium chloride in the solution to generate calcium hydroxide. The specific amount of addition can be adjusted according to the content of ferrous chloride and calcium chloride in the solution; To prepare ferric chloride, the solution after impurities are concentrated and crystallized. The solubility of calcium hydroxide at high temperature is reduced to separate calcium hydroxide from the solution to obtain the finished ferric chloride.

[0033] Embodiment 2: A process for recovering waste residue from a steel ball grinding process, comprising the following steps: Slurry preparation: put the waste residue in a stirring bucket, add water, stir and dilute to obtain slurry, the concentration of the slurry is 20%.

[0034] Particle size classification: Use a water screen to classify the slurry and screen out particles with a size less than 100 microns as ferromagnetic powder for later use; Magnetic separation: dilute the classified slurry with water to make a slurry with a concentration of 20%. First, add 0.5% sodium hexametaphosphate to the diluted slurry and stir for more than 20 minutes. Then add 0.5% water glass and mix. Then pump it into the magnetic separator for magnetic separation. The ferromagnetic powder separated by magnetic separation is set aside. Acid leaching: The tailing mud produced after magnetic separation of the slurry is subjected to solid-liquid separation to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution with a pH of -1.5, and the addition of material is stopped when the pH value of the hydrochloric acid solution reaches 4-6; Drying and screening: The solid-liquid separation of the slurry after acid leaching is carried out to obtain a filter cake, which is then dried and screened using a box dryer to obtain corundum of different particle sizes.

[0035] Impurity removal: After adding hydrogen peroxide to the solution obtained by solid-liquid separation after acid leaching, sodium hydroxide is added to remove calcium chloride in the solution, so that the ferrous chloride in the solution is converted into ferric chloride through hydrogen peroxide, and then calcium hydroxide is reacted with the calcium chloride in the solution to generate calcium hydroxide. The specific amount of addition can be adjusted according to the content of ferrous chloride and calcium chloride in the solution; To prepare ferric chloride, the solution after impurities are concentrated and crystallized. The solubility of calcium hydroxide at high temperature is reduced to separate calcium hydroxide from the solution to obtain the finished ferric chloride.

[0036] Embodiment 3: A process for recovering waste residue from a steel ball grinding process, comprising the following steps: Slurry preparation: Add water to the waste residue for dilution to obtain slurry, the concentration of which is 15%.

[0037] Particle size classification: The slurry is classified by flotation method, and particles with a size less than 100 microns are screened out as ferromagnetic powder for use; Magnetic separation: dilute the classified slurry with water to make a slurry with a concentration of 15%. First, add 0.7% sodium hexametaphosphate to the diluted slurry and stir for more than 20 minutes. Then add 0.3% water glass and mix. Then pump it into the magnetic separator for magnetic separation. The ferromagnetic powder separated by magnetic separation is set aside. Acid leaching: The tailing mud produced after magnetic separation of the slurry is subjected to solid-liquid separation to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution with a pH of -1.5, and the addition of material is stopped when the pH value of the hydrochloric acid solution reaches 4-6; Drying and screening: The slurry after acid leaching is separated into solid and liquid to obtain a filter cake, and the filter cake is dried and screened by a disc dryer to obtain corundum with different particle sizes.

[0038] Impurity removal: After adding hydrogen peroxide to the solution obtained by solid-liquid separation after acid leaching, sodium hydroxide is added to remove calcium chloride in the solution, so that the ferrous chloride in the solution is converted into ferric chloride through hydrogen peroxide, and then calcium hydroxide is reacted with the calcium chloride in the solution to generate calcium hydroxide. The specific amount of addition can be adjusted according to the content of ferrous chloride and calcium chloride in the solution; To prepare ferric chloride, the solution after impurities are concentrated and crystallized. The solubility of calcium hydroxide at high temperature is reduced to separate calcium hydroxide from the solution to obtain the finished ferric chloride.

[0039] The ferromagnetic powder obtained by this process is mainly composed of ferroferric oxide powder, iron powder and corundum. After particle size classification and magnetic separation, ferromagnetic powder with an iron content of more than 36% can be obtained. After being mixed with white mud in equal proportions, it can be directly sold as iron ore powder. The white mud is the waste residue of the light ball process, and its iron content is more than 75%. The corundum obtained after solid-liquid separation in this process is brown corundum abrasive and micro powder with a mesh size of 60 to 1000. The brown corundum micro powder can be used for polishing. The brown corundum particles can be returned to the grinding process after reprocessing, and can also be used in the manufacture of refractory materials, building materials and ceramsite. The finished ferric chloride obtained in this process can be used for sewage treatment, pigment manufacturing, etc.

[0040] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A process for recovering waste residue from a steel ball milling process, characterized in that: The steps include: Slurry preparation: adding waste residue to water for dilution to obtain slurry; Particle size classification: Classify the slurry and select particles with a size less than 100 microns as ferromagnetic powder for future use; Magnetic separation: After the classified slurry is diluted with water, it is sent to a magnetic separator for magnetic separation, and the ferromagnetic powder separated by magnetic separation is kept for later use; Acid leaching: The tailing mud produced after magnetic separation of the slurry is subjected to solid-liquid separation to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution, and the addition of the material is stopped when the pH value of the hydrochloric acid solution reaches 4-6; Drying and screening: The slurry after acid leaching is separated into solid and liquid to obtain a filter cake, and the filter cake is dried and screened to obtain corundum of different particle sizes.

2. The process for recovering waste residue from a steel ball grinding process according to claim 1, characterized in that: This process also includes the following steps: Impurity removal: After adding hydrogen peroxide to the solution obtained by solid-liquid separation after acid leaching, add sodium hydroxide to remove calcium chloride in the solution; To prepare ferric chloride, the impurity-removed solution is concentrated and crystallized to obtain the finished ferric chloride product.

3. The process for recycling waste residue from a steel ball grinding process according to claim 1, characterized in that: In the slurry preparation, the mass concentration of the slurry is 5-20%.

4. The process for recovering waste residue from a steel ball grinding process according to claim 1, characterized in that: In the particle size classification, hydraulic classifier, screening or flotation method is used to classify the slurry.

5. The process for recycling waste residue from a steel ball grinding process according to claim 1, characterized in that: Magnetic separation: dilute the classified slurry with water to prepare a slurry with a mass concentration of 10-20%, and pump the diluted slurry into a magnetic separator for magnetic separation.

6. The process for recovering waste residue from a steel ball grinding process according to claim 5, characterized in that: In the magnetic separation process, 0.5-1.5% of an additive is added to the diluted slurry, stirred, and then pumped into a magnetic separator for magnetic separation. The additive comprises one or two substances selected from sodium hexametaphosphate and water glass.

7. The process for recovering waste residue from a steel ball grinding process according to claim 5, characterized in that: In the magnetic separation process, the mass concentration of the diluted slurry is 10-20%.

8. The process for recycling waste residue from a steel ball grinding process according to claim 6, characterized in that: In the magnetic separation process, the mass concentration of the diluted slurry is 13-17%, and the components of the additive include sodium hexametaphosphate and water glass. The proportion of sodium hexametaphosphate in the additive is 30-70%, and the proportion of water glass is 30-70%.

9. The process for recovering waste residue from a steel ball grinding process according to claim 8, characterized in that: The additive amount is 0.8-1.2%, wherein the proportion of sodium hexametaphosphate in the additive is 45-55%, and the proportion of water glass is 45-55%. When in use, first add the diluted slurry to sodium hexametaphosphate and stir for more than 10 minutes, then add water glass and stir for more than 10 minutes, and then pump the stirred slurry into a magnetic separator for magnetic separation.

10. The process for recycling waste residue from a steel ball grinding process according to claim 1, characterized in that: In the acid leaching process: the tailing mud produced after the slurry is subjected to magnetic separation is separated into solid and liquid to obtain a filter cake, which is then soaked and cleaned with a hydrochloric acid solution with a pH of -1.5, and the addition of material is stopped when the pH value of the hydrochloric acid solution reaches 4-6.