Method for removing impurities from bone china raw material

Abstract

The present application relates to the technical field of ceramic production, and particularly relates to a method for removing impurities from bone china raw materials, comprising the following steps: step 1, applying a 120-mesh grading screen to perform primary screening on the mixed slurry; step 2, applying a 180-mesh grading screen to perform preliminary fine screening on the mixed slurry after the primary screening; and step 3, removing iron impurities through a seven-step progressive electromagnetic iron removal method. The present application applies a "7-filter 5-screen" process, that is, the slurry is subjected to seven high-strength electromagnetic iron removers and five high-mesh rotary vibrating screens, and the iron impurities are removed through the progressive electromagnetic iron removal method, so that the harmful impurities are completely removed, the ceramic prepared by using the raw materials has good light transmittance, the ceramic quality is fine, moist, and transparent, the color tone is white, warm, and jade-like, and the product grade is obviously improved.

Description

Technical Field

[0001] This invention relates to the field of ceramic production technology, specifically to a method for removing impurities from bone china raw materials. Background Technology

[0002] In the production of daily-use ceramics, raw material preparation is a fundamental process. Its purpose is to finely crush multi-component raw materials with water to form a slurry, achieving fine particles that facilitate the sintering reaction. Simultaneously, it removes iron-containing coloring impurities and trace amounts of coarse particles from the slurry, as these significantly affect the whiteness and translucency of the porcelain, thus impacting its aesthetic appeal. Bone china, belonging to the category of daily-use ceramics, is a globally recognized high-end porcelain type. It is characterized by its exquisite materials, meticulous craftsmanship, and strict standards, resulting in high whiteness, delicate translucency, and a lustrous, smooth glaze.

[0003] Iron impurities are the biggest concern in bone china production. At best, they affect the whiteness of the porcelain body; at worst, they create clay-like defects, lowering the product's grade. The raw material preparation process for removing impurities requires electromagnetic separators and vibrating screens. Factories typically use electromagnetic separators with magnetic field strengths between 10,000 and 30,000 Gauss, and vibrating screens with mesh sizes ranging from 180 to 325 mesh, connected in series. The raw material preparation process is completed by the slurry undergoing iron removal and sieving. Currently, most bone china manufacturers' raw material preparation processes involve two iron removals and two sievings of the slurry (e.g.,...). Figure 1 As shown), a very small number of enterprises adopt the three-time iron removal and three-time sieving process. Its disadvantages are: (1) There are residual components of fine impurities in the slurry, and the amount of residual components is unstable as the impurity content in the raw materials changes, resulting in the porcelain color being yellowish - the fine iron impurities are colored and the light transmittance is poor; (2) The magnetic field strength of the electromagnetic iron remover is between 10,000 and 30,000 Gauss, and the iron removal is not sufficient; (3) The recycled blank and the formula raw materials are ground together into a slurry, mixed evenly, and then the iron removal and sieving process is carried out. The harmful impurities in the recycled blank are ground up, which increases the difficulty of removing fine impurities. Summary of the Invention

[0004] To address the above problems, this invention provides a method for removing impurities from bone china raw materials, comprising the following steps: Step 1: Use a 120-mesh grading screen to coarsely screen the mixed slurry; Step 2: Use a 180-mesh grading screen to perform preliminary fine screening on the mixed slurry after the initial screening; Step 3: Remove iron impurities using a seven-step progressive electromagnetic iron removal method.

[0005] This invention employs a seven-step progressive electromagnetic iron removal process to improve the particle size at which fine iron-containing impurities are removed, resulting in bone china raw materials with ultra-low iron content (≤1‰). Simultaneously, a vibrating sieve removes particulate harmful impurities from the recycled raw material, preventing secondary grinding and effectively reducing the difficulty of removing fine impurities. The progressive nature of this invention refers to the use of a series of enhanced electromagnetic iron separators and progressively larger mesh screens to gradually improve the adsorption capacity and screening effect for iron impurities. Each iron separator may have different magnetic field strengths and fluctuations to ensure that even smaller iron impurities of varying sizes can be removed. This progressive electromagnetic iron removal method reduces material waste and equipment maintenance costs, offering significant cost-effectiveness in the long run.

[0006] Furthermore, in step 1, the mixed slurry is processed by a ball mill, and the screen is made of stainless steel.

[0007] Furthermore, the mesh screen has round holes.

[0008] Furthermore, in step 2, the vibration intensity of the vibrating screen is 1.2 times that in step 1. The increase in intensity is mainly due to the fact that the aperture size of the 180-mesh screen is 1.5 times smaller than that of the 120-mesh screen, resulting in a larger specific surface area of ​​the particles to be sorted. Increasing the vibration intensity can effectively improve the screening efficiency, and the 1.2 times vibration intensity is the result of comprehensively considering the screen's resonance characteristics and the overall stability of the equipment.

[0009] Furthermore, step 3 includes the following steps: Step 3-1: Use a 30,000 Gauss variable electromagnetic separator to remove ferrous impurities from the mixed slurry. The variable magnetic field fluctuation can cause dynamic fluctuations in the ferromagnetic impurities inside the slurry, which can promote the disorder of the ferromagnetic impurities and generate a certain degree of agitation inside the slurry, thereby enhancing the separation effect between ferromagnetic impurities and non-magnetic materials. Through the fluctuation effect, the impurities are pushed to the surface or edge of the slurry, causing the ferromagnetic impurities to gather towards the boundary.

[0010] Step 3-2: Use a 30,000 Gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry. The function of using a constant magnetic field separator is to efficiently adsorb ferromagnetic impurities that have accumulated at the boundary and surface after being subjected to a variable magnetic field. The stable electromagnetic characteristics ensure that the adsorbed ferromagnetic impurities are not prone to secondary shedding, thereby improving the removal effect.

[0011] Step 3-3: Use a 250-mesh vibrating screen to finely classify and screen the particles after electromagnetic iron removal; Steps 3-4: Use a 30,000 Gauss variable electromagnetic separator to remove ferromagnetic impurities from the mixed slurry; Steps 3-5: Use a 30,000 gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry; Steps 3-6: Use a 325-mesh grading screen to perform ultra-fine screening of the mixed slurry to remove impurity particles; Steps 3-7: Use a 40,000 Gauss constant electromagnetic separator to adsorb heavier and finer ferromagnetic impurities, thereby effectively capturing and separating fine impurities and adsorbing ferromagnetic particles. Steps 3-8: Use a 325-mesh grading screen to remove any remaining impurities that were not completely removed. Steps 3-9: Apply a 30,000 Gauss constant electromagnetic separator to enhance iron removal; Steps 3-10: Enhance iron removal using a 30,000 Gauss constant electromagnetic separator. The 30,000 Gauss intensity is repeated twice. The first step preferentially adsorbs impurities with strong ferromagnetic properties and larger particle sizes. However, as the adsorption volume accumulates, the surface adsorption capacity of the ferromagnetic impurities decreases, resulting in some small-sized, weakly ferromagnetic impurities in a mixed state failing to be effectively adsorbed and removed. Therefore, a second 30,000 Gauss adsorption process is used to further remove impurities missed in the previous step, significantly improving the impurity removal effect. The second step primarily removes residual impurities with poor ferromagnetic properties and those missed. Simultaneously, the two repeated iron removal processes with constant low magnetic field strength reduce the load on the equipment, lessen wear, and extend the equipment's service life.

[0012] Furthermore, in step 3-1, the magnetic field strength fluctuation of the 30,000 Gauss variable electromagnetic separator is ±15%. This is mainly because the particle size of ferromagnetic impurities after the flowing slurry passes through 120-mesh and 180-mesh vibrating screens is below 0.08mm. When ferromagnetic impurities of this size are in a fluctuating, non-uniform magnetic field, the magnitude and direction of the magnetic field acting on the particles change with their position, resulting in an imbalance of forces on the particles in the magnetic field. Analysis and experiments show that a ±15% magnetic field strength fluctuation will cause ferromagnetic impurity particles to move more significantly towards higher magnetic field strengths, thus making them easier to capture and separate by magnetic separation.

[0013] Furthermore, in step 3-4, the magnetic field strength fluctuation of the 30,000 Gauss variable electromagnetic separator is ±10%. The reason for adjusting the fluctuation to ±10% is that, based on step 3-1, the ferromagnetic impurities processed by the 250-mesh vibrating screen in step 3-3 have smaller particle sizes. Therefore, according to the optimal non-equilibrium force movement mechanism of ferromagnetic impurities under a non-uniform magnetic field described in step 3-1, adjusting the magnetic field fluctuation strength to ±10% yields the best results.

[0014] Furthermore, in step 5, the 325-mesh grading screen is a 325-mesh vibrating screen.

[0015] Furthermore, the 325-mesh grading screen is made of stainless steel.

[0016] Furthermore, the 325-mesh grading screen has round, dot-shaped protrusions with a diameter of less than 3 micrometers on its wire surface. This facilitates the removal of harmful particles with a diameter of 40 micrometers or larger while significantly reducing the adhesion of the screen to the raw materials, thus enhancing the filtration effect and efficiency. In addition, the round protrusions help prevent the accumulation of dirt or deposits on the fluid flow surface.

[0017] The beneficial effects of this invention are: (1) The present invention improves the magnetic field strength of the electromagnetic iron separator to 30,000 or 40,000 Gauss, thereby increasing the removal of fine iron-containing impurities; the vibrating screen adopts a 325 mesh stainless steel screen, abandoning the low mesh screen, and effectively removes harmful material particles with a diameter of more than 40 micrometers.

[0018] (2) After multiple tests, it was found that the iron-containing impurities in the slurry could only be completely removed after 7 electromagnetic iron removers and 5 rotary vibrating screens.

[0019] (3) The recycled billet contains large particles of impurities mixed in during the molding process, but no fine iron impurities. Therefore, the recycled billet is stirred with water in the material well to form a slurry. The slurry is then screened once to remove large particles of impurities. This avoids the large particles of impurities being crushed and instead they are directly screened out by the vibrating screen. Then the recycled billet slurry is mixed with the formula raw material slurry and then passed through 7 electromagnetic iron removers and 5 vibrating screens before reaching the next pressing and filtering process. This achieves the complete and thorough removal of harmful impurities in the slurry.

[0020] In summary, this invention has excellent application effects in the field of ceramic production technology. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the existing iron removal screening process.

[0022] Figure 2 This is a schematic diagram of the seven-filter, five-screen process of the present invention.

[0023] Figure 3 This is a schematic diagram of a 325-mesh vibrating screen structure.

[0024] Figure 4 It is a ceramic produced by firing the raw materials prepared by the method of this invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments.

[0026] This invention provides a method for removing impurities from bone china raw materials, such as... Figure 2 As shown. The method of the present invention mainly includes three main steps. To clearly illustrate the present invention, the three steps are described as follows: Step 1: Use a 120-mesh grading screen to coarsely screen the mixed slurry.

[0027] In this step, the mixed slurry prepared by the ball mill is coarsely screened through a 120-mesh stainless steel grading screen to remove coarser particles. The 120-mesh stainless steel screen is designed with round holes, which increases the collision and refinement effect on the surface of irregular particles during the vibratory screening.

[0028] Step 2: Use a 180-mesh grading screen to perform preliminary fine screening on the mixed slurry after the initial screening.

[0029] In this step, the mixed slurry after the initial screening is fed into a 180-mesh grading screen for preliminary fine screening, so that the mixed slurry achieves a more uniform particle size distribution; in this stage of screening, the vibration intensity of the rotary vibrating screen is increased to 1.2 times that in step 1, so as to improve the efficiency of fine screening.

[0030] Step 3: Remove iron impurities using a seven-step progressive electromagnetic iron removal method.

[0031] The progressive approach of this invention refers to the gradual improvement of the adsorption capacity and screening effect for iron impurities through a series of enhanced electromagnetic separators and progressively larger mesh screens. Each separator may have different magnetic field strengths and fluctuations to ensure that smaller iron impurities of different sizes can be removed. This process includes the following 10 sub-steps.

[0032] Step 3-1: Use a 30,000 Gauss variable electromagnetic separator to remove ferrous impurities from the mixed slurry.

[0033] The finely screened slurry is sent to a 30,000 gauss electromagnetic separator to remove ferrous impurities from the raw material. The electromagnetic separator is set with a fluctuating magnetic field strength of ±15%. The variable magnetic field helps to process the material more evenly and ensures that all parts receive proper iron removal treatment.

[0034] Step 3-2: Use a 30,000 Gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry.

[0035] The mixed slurry processed in step 3-1 is fed into a 30,000 gauss constant electromagnetic separator to increase the attraction to ferromagnetic impurities, thereby improving the iron removal efficiency.

[0036] Step 3-3: Use a 250-mesh vibrating screen to finely classify and screen the particles after electromagnetic iron removal.

[0037] The mixed slurry processed in step 3-2 is fed into a 250-mesh classifying vibrating screen to finely classify and screen the particles after primary electromagnetic iron removal.

[0038] Steps 3-4: Use a 30,000 Gauss variable electromagnetic separator to remove ferromagnetic impurities from the mixed slurry.

[0039] The mixed slurry after screening in step 3-3 is passed through a 30,000 Gauss electromagnetic separator to remove ferromagnetic impurities. The magnetic field strength of this 30,000 Gauss variable electromagnetic separator fluctuates by ±10%. The lower fluctuation of the magnetic field can better adapt to the differences in ferromagnetic impurities of different fine particle types, thereby improving the flexibility and effectiveness of iron removal.

[0040] Steps 3-5: Use a 30,000 Gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry.

[0041] The mixed slurry processed in steps 3-4 is fed into a 30,000 gauss constant electromagnetic separator for progressively enhanced iron removal.

[0042] Steps 3-6: Use a 325-mesh grading screen to perform ultra-fine screening of the mixed slurry to remove impurity particles.

[0043] The mixed slurry processed in steps 3-5 is passed through a 325-mesh grading screen for further ultra-fine screening to remove impurity particles. The 325-mesh grading screen is a 325-mesh vibrating screen made of stainless steel. The wires of the 325-mesh grading screen have round, dot-shaped protrusions with a diameter of less than 3 micrometers attached to them. Figure 3 This is a structural diagram of a 325-mesh stainless steel vibrating screen. The 325-mesh vibrating screen uses stainless steel mesh with round, dot-shaped barbs less than 3 micrometers in diameter attached to the wire surface. The shape of these barbs reduces the adhesion of slurry materials to the screen surface because they break up the continuous layer of slurry on the screen, making it less likely for impurities to adhere. This reduces clogging of the screen pores, keeps the screen clear, and extends its service life. Additionally, the barbs enhance the screen's hydrophobicity, facilitating the removal of moisture from the screen surface. Especially when processing wet slurries, the barb design helps to more effectively separate solid particles and liquids in the slurry, improving separation efficiency.

[0044] Steps 3-7: Use a 40,000 variable gauss separator to adsorb heavier and finer ferromagnetic impurities, achieving effective capture and separation of fine impurities and adsorbing ferromagnetic particles.

[0045] The mixed slurry after the fine screening process in steps 3-6 is sent to a 40,000 variable iron remover to adsorb heavier and finer ferromagnetic impurities, thereby achieving effective capture and separation of fine impurities and adsorption of ferromagnetic particles.

[0046] Steps 3-8: Use a 325-mesh grading screen to remove any remaining impurities that were not completely removed.

[0047] The mixed slurry processed in steps 3-7 is sent to a 325-mesh grading screen a second time to remove any remaining impurities, further cleaning and improving the purity of the slurry.

[0048] Steps 3-9: Apply a 30,000 Gauss constant electromagnetic separator to enhance iron removal.

[0049] The mixed slurry processed in steps 3-8 is sent to a 30,000 gauss constant electromagnetic separator for enhanced iron removal.

[0050] Steps 3-10: Apply a 30,000 Gauss constant electromagnetic separator to enhance iron removal.

[0051] The mixed slurry processed in steps 3-9 is passed through a 30,000 Gauss constant electromagnetic separator for progressively enhanced iron removal, thereby improving the purity of the slurry.

[0052] Figure 4 This ceramic is fired based on raw materials prepared using the method of this invention. As can be seen from the figure, ceramics prepared using the method of this invention have good translucency, a delicate, smooth, and translucent texture, and a pure white, warm, and jade-like color, significantly enhancing the product's quality. Furthermore, product quality has been significantly improved; the percentage of defects caused by clay impurities has decreased from over 1.2% to 0.2%, and the first-grade product rate has increased by more than 1%. Currently, monthly production is 1.2 million pieces, with an additional 12,000 first-grade products per month, resulting in a monthly cost reduction and increased profits of over 50,000 yuan for the company.

[0053] In summary, this invention provides a method for removing impurities from bone china raw materials, comprising: Step 1, initial screening of the mixed slurry using a 120-mesh grading screen; Step 2, preliminary fine screening of the initial-screened mixed slurry using a 180-mesh grading screen; Step 3, removal of iron impurities using a seven-step progressive electromagnetic iron removal method. This invention employs a "7-filter, 5-screen" process, meaning the slurry passes through a high-intensity electromagnetic iron remover seven times and a high-mesh vibrating screen five times, removing iron impurities through a progressive electromagnetic iron removal method. This achieves relatively complete removal of harmful impurities. Ceramics prepared using these raw materials have good translucency, a delicate, smooth, and translucent texture, and a pure white, warm, and jade-like color, significantly enhancing the product's quality.

[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for removing impurities from bone china raw materials, characterized in that, Includes the following steps: Step 1: Use a 120-mesh vibrating screen to coarsely screen the mixed slurry; Step 2: Use a 180-mesh grading vibrating screen to perform preliminary fine screening on the mixed slurry after the initial screening; Step 3: Remove iron impurities using a seven-step progressive electromagnetic iron removal method; Step 3 includes the following steps: Step 3-1: Use a 30,000 Gauss variable electromagnetic separator to remove ferrous impurities from the mixed slurry; Step 3-2: Use a 30,000 gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry; Step 3-3: Use a 250-mesh vibrating screen to finely classify and screen the particles after electromagnetic iron removal; Steps 3-4: Use a 30,000 Gauss variable electromagnetic separator to remove ferromagnetic impurities from the mixed slurry; Steps 3-5: Use a 30,000 gauss constant electromagnetic separator to remove ferrous impurities from the mixed slurry; Steps 3-6: Use a 325-mesh grading vibrating screen to perform ultra-fine screening of the mixed slurry and remove impurity particles; Steps 3-7: Use a 40,000 Gauss constant electromagnetic separator to adsorb heavier and finer ferromagnetic impurities, thereby effectively capturing and separating fine impurities and adsorbing ferromagnetic particles. Steps 3-8: Use a 325-mesh grading vibrating screen to remove any remaining impurities that were not completely removed. Steps 3-9: Apply a 30,000 Gauss constant electromagnetic separator to enhance iron removal; Steps 3-10: Apply a 30,000 Gauss constant electromagnetic separator to enhance iron removal.

2. The method for removing impurities from bone china raw materials as described in claim 1, characterized in that: The screen has round holes.

3. The method for removing impurities from bone china raw materials as described in claim 2, characterized in that: The vibration intensity of the rotary vibrating screen in step 2 is 1.2 times that in step 1.

4. The method for removing impurities from bone china raw materials as described in claim 3, characterized in that: In step 3-1, the magnetic field strength fluctuation of the 30,000 Gauss variable electromagnetic separator is ±15%.

5. The method for removing impurities from bone china raw materials as described in claim 4, characterized in that: In steps 3-4, the magnetic field strength fluctuation of the 30,000 Gauss variable electromagnetic separator is ±10%.

Images