A monolithic ceramic filter plate for dewatering low-grade iron ore concentrate and a method for manufacturing the same

Abstract

The application discloses a monolithic structure ceramic filter plate for low-grade iron concentrate dewatering and a preparation method thereof, and belongs to the technical field of ceramic filter plates.The application is characterized in that: a ceramic 3D printing material is prepared, and a double-head double-precision 3D printer is used to layer-by-layer print a monolithic structure ceramic filter plate base body; the base body mud blank is dried and fired, coated and fired again, and then a water outlet nozzle and a positioning hole are installed to obtain the monolithic structure ceramic filter plate for low-grade iron concentrate dewatering.The application reduces the surface roughness of the monolithic structure ceramic filter plate, improves the corrosion resistance and service life; the 3D printing technology is used to make the inner cavity of the monolithic structure ceramic filter plate have better symmetry, reduce the corrosion and damage caused by the too thin side of the filter plate, and the unique inner cavity column design has higher water flux under the premise of ensuring the strength of the base body, and the resistance caused by the reduction of the micro-pore diameter is compensated.

Description

Technical Field

[0001] This invention belongs to the field of ceramic filter plate technology, specifically relating to an integral structure ceramic filter plate for dewatering low-grade iron concentrate and its preparation method. Background Technology

[0002] Currently, there are two main types of ceramic filter plates on the market. One type is formed by dry pressing and firing followed by resin bonding to create a cavity. The cavity volume of this type of ceramic filter plate is too small, resulting in low dehydration efficiency and insufficient production capacity. The other type is a wet-process grouting integral ceramic filter plate. The cavity of this type of ceramic filter plate is filled with organic matter and formed by high-temperature gasification. Since the organic filler cannot be effectively positioned, the cavity of this type of ceramic filter plate is mostly not centered, and the thin-walled side is prone to corrosion and damage after use, leading to premature scrapping. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a method for preparing an integral structure ceramic filter plate for dewatering low-grade iron concentrate, so that the obtained product has better dewatering performance and a longer service life.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for preparing an integral ceramic filter plate for dewatering low-grade iron concentrate, comprising the following steps:

[0006] 1) Prepare material A by mixing white corundum, clay, potassium feldspar, sodium silicate in a ratio of 100:5:(10-15):(5-8) in a mixer for 5-15 minutes; prepare liquid B by mixing coupling agent, silica sol, and water in a ratio of (0.5-1.5):5:(12-17); continuously spray atomized liquid B into the mixer containing material A while stirring, and mix for 10-20 minutes to obtain material C.

[0007] 2) Place material C into the mixing drum of a dual-head, dual-precision 3D printer, and while stirring, add 2.5 to 4 parts of binder and 0.2 to 0.4 parts of curing agent. Stir for 10 to 15 minutes to obtain printing material D;

[0008] 3) Open the computer control system, import the corresponding printing program, and use the dual-head dual-precision 3D printer to print layer by layer. The low-precision print head is responsible for printing the main structure of the overall ceramic filter plate, and the high-precision print head is responsible for printing and modifying the inner and outer surfaces of the overall ceramic filter plate.

[0009] 4) After printing, send the printed blank into a dryer and dry it at 80℃~100℃ until constant weight;

[0010] 5) Place the dried green body in the kiln for firing. After degreasing, heat it to 1290℃~1350℃, keep it at that temperature for 2~7 hours, then turn off the fire. Cool it down to 900℃ at a rate of 5~10℃ per minute, and then cool it down to room temperature at a rate of 1~3℃ per minute. After cooling, you will get the integral structure ceramic filter plate substrate. Grind it to the dimensions in the drawing using a grinder or grinding wheel.

[0011] 6) Prepare an E-film slurry by mixing alumina powder, clay, polyvinyl alcohol, and water in a ratio of 100:(3-6):(0.5-1):65 and ball milling for 2-3 hours; use a high-pressure atomizing spraying equipment to evenly spray the E-film slurry onto the surface of the processed integral structure ceramic filter plate substrate.

[0012] 7) The integral structure ceramic filter plate substrate with the sprayed film slurry is sent to the dryer and dried at 80℃~100℃ to constant weight. The dried integral structure ceramic filter plate is then fired, heated to 1150℃~1250℃ and held for 2~5 hours before being turned off. After cooling, the integral structure ceramic filter plate is obtained.

[0013] 8) Drill holes in the integral ceramic filter plate obtained in step 7), install positioning holes and water outlets to obtain an integral ceramic filter plate for dewatering low-grade iron concentrate.

[0014] Preferably, in step 1), the white corundum has a particle size of 200-260 mesh, with an Al2O3 content of ≥99%; the clay is one or both of montmorillonite or kaolinite mineral clays, with a clay particle size D50 of 5-8 μm; and the sodium silicate has a water content of 20%.

[0015] Preferably, in step 1), the coupling agent is vinyltris(β-methoxyethoxy)silane; the silica sol solid content is 30-35%.

[0016] Preferably, in step 2), the binder is furan resin with a density of 1.05–1.25 g / cm³. 3 .

[0017] Preferably, in step 2), the curing agent is a sulfonic acid-based curing agent with a density of 1–1.3 g / cm³. 3 The total acid content is 31-35%.

[0018] Preferably, in step 3), the low-precision print head of the dual-head dual-precision 3D printer has a printing accuracy of 3-5mm, and the high-precision print head has a printing accuracy of 0.3-0.5mm.

[0019] Preferably, in step 6), the viscosity of polyvinyl alcohol is 20-25 mPa·s.

[0020] Preferably, in step 6), the alumina powder has a particle size distribution D50 of 3–5 μm; the clay is one or both of montmorillonite or kaolinite mineral clays, and the clay particle size is 5–8 μm.

[0021] Preferably, in step 6), the pressure of the high-pressure atomizing spraying equipment is 0.45 to 0.6 MPa.

[0022] The integral structure ceramic filter plate obtained by the preparation method of the integral structure ceramic filter plate for dewatering low-grade iron concentrate.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0024] 1) This invention uses a preferred ratio of main material and sintering aid, as well as a preferred firing curve, to reduce microscopic crystal defects, resulting in higher mechanical strength and better corrosion resistance than conventional ceramic filter plates, thus extending service life in strong acid cleaning environments.

[0025] 2) This invention uses finer-grained main materials, resulting in smaller microscopic capillary pores. Using resin binder as a pore-forming agent, liquid-phase solidification improves pore dispersion, eliminates pore agglomeration, and narrows the pore size distribution. In the field of dewatering low-grade iron concentrate, this can lead to lower moisture content in the ore cake.

[0026] 3) The 3D printing technology used in this invention enables the overall ceramic filter plate to have a thinner wall thickness and a larger cavity structure, resulting in lower filtration resistance, greater water flow, and higher dehydration efficiency.

[0027] 4) The 3D printing technology used in this invention makes the overall structure of the ceramic filter plate more symmetrical, reducing the possibility that the ceramic filter plate is too thin on one side, which may lead to accelerated corrosion and damage.

[0028] 5) The high-precision printhead used in this invention performs fine printing on the inner and outer layers of the overall ceramic filter plate, reducing the surface roughness of the ceramic filter plate and increasing its corrosion resistance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a dual-head, dual-precision 3D printer;

[0030] Figure 2 This is a schematic diagram of the cross-section of the overall structure ceramic filter plate;

[0031] Figure 3 This is a schematic diagram of the cross-section of the overall structure ceramic filter plate. Detailed Implementation

[0032] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0033] Example 1

[0034] like Figure 3 As shown, the integral structure ceramic filter plate for dewatering low-grade iron concentrate provided by the present invention consists of an integral structure ceramic filter plate substrate 1 and a membrane layer 2. The substrate 1 is mainly composed of porous ceramic composed of corundum matrix and mullite phase, and the membrane layer is mainly composed of porous alumina ceramic.

[0035] The preparation method of the above-mentioned integral ceramic filter plate for dewatering low-grade iron concentrate includes the following specific steps:

[0036] 1) Prepare material A and liquid B according to the components in Table 1. During the mixing process in the mixer, spray liquid B into material A using an atomizing spray method, mixing for 10-20 minutes while spraying, to obtain material C. Place material C into the mixing drum of a dual-head dual-precision 3D printer, and add the binder and curing agent from Table 1 to obtain printing material D;

[0037] Table 1. Composition and Requirements of Material A and Liquid B

[0038]

[0039] 2) The mixed printing material D is transferred to the print head through the pipe below the mixing cylinder. The dual-head dual-precision 3D printer prints layer by layer according to the set program. The low-precision print head is responsible for printing the main structure of the overall ceramic filter plate, while the high-precision print head is responsible for printing and modifying the inner and outer surfaces of the overall ceramic filter plate.

[0040] 3) After printing, send the printed blank into a dryer and dry it at 80℃~100℃ until constant weight;

[0041] 4) Place the dried green body in a kiln for firing. After degreasing, raise the temperature to 1290℃~1350℃, hold for 2~7 hours, then turn off the kiln. Cool the temperature down to 900℃ at a rate of 5~10℃ per minute, and then cool it to room temperature at a rate of 1~3℃ per minute. After cooling, you will obtain the integral structure ceramic filter plate substrate. Grind it to the dimensions shown in the drawing using a grinder or grinding wheel.

[0042] 5) Prepare an E-film slurry by mixing alumina powder, clay, polyvinyl alcohol, and water in a ratio of 100:(3-6):(0.5-1):65 and ball milling for 2-3 hours; use a high-pressure atomizing spraying equipment to evenly spray the E-film slurry onto the surface of the processed integral structure ceramic filter plate substrate.

[0043] 6) The integral structure ceramic filter plate substrate with the sprayed film slurry is sent to the dryer and dried at 80℃~100℃ to constant weight. The dried integral structure ceramic filter plate is then fired, heated to 1150℃~1250℃ and held for 2~5 hours before being turned off. After cooling, the integral structure ceramic filter plate is obtained.

[0044] 7) Drill holes in the above-mentioned integral structure ceramic filter plate, install positioning holes and water outlets, etc., to obtain an integral structure ceramic filter plate for dewatering low-grade iron concentrate.

[0045] A dual-head, double-precision 3D printer for integral ceramic filter plate molding, such as... Figure 1 As shown, the 3D printer consists of a mixing cylinder 1, a feeding pipeline 3, a low-precision print head 5, a high-precision print head 6, an X-axis track 7, a Y-axis track 8, a Z-axis track 9, a printing platform 10, and a computer control system 11. The mixing cylinder 1 includes a material container and a stirrer, the stirrer being driven by a motor to continuously stir the material. The feeding pipeline 3 includes an electrically controlled valve 2, a rigid pipeline 3, and a flexible pipeline 4 connected to the print head. A spiral auger in the rigid pipeline transports the printing material D from the mixing cylinder to the flexible pipeline 4. The low-precision print head 5 and the high-precision print head 6 are powered by an air pump to extrude the printing material at a uniform speed. Print heads 5 and 6 have built-in electric heating components to heat the printing material D to a suitable printing temperature. The low-precision print head 5 has a printing precision of 3-5 mm and is responsible for printing the main structure of the overall ceramic filter plate; the high-precision print head has a printing precision of 0.3-0.5 mm and is responsible for printing and finishing the inner and outer surfaces of the overall ceramic filter plate. X-axis track 7, Y-axis track 8, and Z-axis track 9 consist of sliders, rigid tracks, and stepper motors. X-axis track 7 and Y-axis track 8 are connected to print heads 5 and 6, respectively, while the Z-axis track is connected to the printing platform 10. The computer control system controls the direction and speed of movement according to the printing program. The printing platform 10 is a movable, rigid, heat-resistant flat plate connected to the Z-axis track 9, responsible for supporting the printed part from the start of printing until drying. The computer control system 11 consists of computer-controlled drives and 3D printing software, connecting the electronically controlled valve 2, low-precision print head 5, high-precision print head 6, X-axis track 7, Y-axis track 8, and Z-axis track 9, and is responsible for controlling the linkage of various components during the printing process.

[0046] Printing process: Pour the prepared material C into the mixing cylinder 1, add binder and curing agent, and turn on the agitator to continuously stir to form printing material D. Turn on the computer system 11 and 3D printing software, and import the printing program. The printing program opens the electric control valve 2, starts the auger in the feeding pipeline 3 to transport the printing material D to the flexible pipeline and print head 5 and 6, and the electric heating starts heating. The X-axis track 7, Y-axis track 8 and Z-axis track 9 move according to the program, and the air pump extrudes the printing material D from the printing port, performing double-precision layer-by-layer printing until the printed part is completed, obtaining the integral structure ceramic filter plate matrix blank.

[0047] In this embodiment, the integral ceramic filter plate substrate is formed using 3D printing. Pre-fabricated printing material is printed layer by layer by a dual-head, dual-precision 3D printer according to the printing program. Due to the high printing precision, the inner and outer surfaces of the integral ceramic filter plate substrate are free of roughness and defects, making it less susceptible to corrosion. Furthermore, the substrate cavity is centrally located, and the thickness on both sides of the cross-section is consistent, preventing the ceramic filter plate from breaking rapidly due to excessive load on one side. The unique internal column design ensures high water throughput while maintaining substrate strength, compensating for the resistance caused by the reduced micropore size.

[0048] Example 2

[0049] An integral ceramic filter plate for dewatering low-grade iron concentrate was prepared using the method described in Example 1, and the performance of the product was tested. The specific results are shown in Table 2. Specifically, the flexural strength was tested according to GB / T 6569-1986; the water absorption rate and porosity were tested according to GB / T 1966-1996; the median pore size was tested according to GB / T21650.1-2008; the acid corrosion mass loss rate was tested according to GB / T 1970-1996; and the water flux was tested by connecting the ceramic filter plate to a 100 kPa positive pressure water pipe and recording the volume of pure water passing through it in one minute.

[0050] Table 2 Product Composition and Performance Results

[0051]

[0052] In the table, the white fused alumina particle size is 240 mesh; the clay is kaolin powder with a particle size D50 of 6 μm; the coupling agent is vinyltris(β-methoxyethoxy)silane; the silica sol solid content is 30%; and the binder is furan resin with a density of 1.1 g / cm³. 3 The curing agent is a sulfonic acid-based curing agent with a density of 1.1 g / cm³. 3 The total acid content is 32%; the alumina powder particle size D50 is 5μm; and the viscosity of polyvinyl alcohol is 25mPa·s.

[0053] This invention utilizes 3D printing to form a monolithic ceramic filter plate substrate, which is then dried, coated, and fired to produce a monolithic ceramic filter plate for dewatering low-grade iron concentrate. This plate efficiently dewaters iron concentrate slurry, and the moisture content of the filter cake meets the production requirements of mining enterprises. Furthermore, the monolithic ceramic filter plate of this invention exhibits good acid resistance and corrosion resistance, resulting in a longer service life than conventional ceramic filter plates on the market.

[0054] Comparative Example 1

[0055] The target product is prepared using the formulation and preparation method of Product 1 in Example 2.

[0056] (1) When preparing printing material D, the comparative example is 1:10 parts water, and other components and preparation process remain unchanged.

[0057] (2) In step 3), when the prepared printing material D is printed using a dual-head dual-precision 3D printer, Comparative Example 1 cannot be printed, no printing material is extruded from the print head, and the forming fails.

[0058] Comparative Example 2

[0059] The target product is prepared using the formulation and preparation method of Product 1 in Example 2.

[0060] (1) When preparing printing material D, the ratio of comparative example 2 is 15 parts water and 7 parts binder, while other components and preparation process remain unchanged.

[0061] (2) In step 3), when the prepared printing material D is printed using a dual-head dual-precision 3D printer, Comparative Example 2 cannot be printed. No printing material is extruded from the print head, and the forming fails.

[0062] Comparative Example 3

[0063] The target product is prepared using the formulation and preparation method of Product 1 in Example 2.

[0064] (1) When preparing printing material D, the comparative example 3: 20 parts potassium feldspar, 8 parts silica sol, and other components and preparation process remain unchanged.

[0065] (2) After step 8), the water absorption rate and porosity of the comparative example 3 were both low, and the water flux test value was far below the product requirements. The product was unqualified and could not be used.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for the preparation of monolithic ceramic filter plates for the dewatering of low-grade iron ore concentrates, characterized in that, The specific steps are as follows: 1) Prepare material A by mixing white corundum, clay, potassium feldspar, sodium silicate in a ratio of 100:5:(10-15):(5-8) in a mixer for 5-15 minutes; prepare liquid B by mixing coupling agent, silica sol, and water in a ratio of (0.5-1.5):5:(12-17); continuously spray atomized liquid B into the mixer containing material A while stirring, and mix for 10-20 minutes to obtain material C. 2) Place material C into the mixing drum of a dual-head, dual-precision 3D printer, and while stirring, add 2.5 to 4 parts of binder and 0.2 to 0.4 parts of curing agent. Stir for 10 to 15 minutes to obtain printing material D; 3) Open the computer control system, import the corresponding printing program, and use the dual-head dual-precision 3D printer to print layer by layer. The low-precision print head is responsible for printing the main structure of the overall ceramic filter plate, while the high-precision print head is responsible for printing and modifying the inner and outer surfaces of the overall ceramic filter plate. 4) After printing, send the printed blank into a dryer and dry it at 80℃~100℃ until constant weight; 5) Place the dried green body in the kiln for firing. After degreasing, heat it to 1290℃~1350℃, keep it at that temperature for 2~7 hours, then turn off the fire. Cool it down to 900℃ at a rate of 5~10℃ per minute, and then cool it down to room temperature at a rate of 1~3℃ per minute. After cooling, you will get the integral structure ceramic filter plate substrate. Grind it to the dimensions in the drawing using a grinder or grinding wheel. 6) Prepare an E-film slurry by mixing alumina powder, clay, polyvinyl alcohol, and water in a ratio of 100:(3-6):(0.5-1):65 and ball milling for 2-3 hours; use a high-pressure atomizing spraying equipment to evenly spray the E-film slurry onto the surface of the processed integral structure ceramic filter plate substrate. 7) The integral structure ceramic filter plate substrate with the sprayed film slurry is sent to the dryer and dried at 80℃~100℃ to constant weight. The dried integral structure ceramic filter plate is then fired, heated to 1150℃~1250℃ and held for 2~5 hours before being turned off. After cooling, the integral structure ceramic filter plate is obtained. 8) Drill holes in the integral ceramic filter plate obtained in step 7), install positioning holes and water outlets to obtain an integral ceramic filter plate for dewatering low-grade iron concentrate. The dual-head dual-precision 3D printer consists of a mixing cylinder (1), a feeding pipe (3), a low-precision print head (5), a high-precision print head (6), an X-axis track (7), a Y-axis track (8), a Z-axis track (9), a printing platform (10), and a computer control system (11). The low-precision print head (5) has a printing precision of 3-5 mm, and the high-precision print head has a printing precision of 0.3-0.5 mm.

2. The method for preparing a monolithic ceramic filter plate for dewatering low-grade iron ore concentrates according to claim 1, characterized in that, In step 1), the white corundum has a particle size of 200-260 mesh, with an Al2O3 content of ≥99%; the clay is one or both of montmorillonite or kaolinite mineral clays, with a clay particle size D50 of 5-8 μm; and the sodium silicate has a water content of 20%.

3. The method for preparing a monolithic ceramic filter plate for dewatering low-grade iron ore concentrates according to claim 1, characterized in that, In step 1), the coupling agent is vinyltris(β-methoxyethoxy)silane; the silica sol solid content is 30-35%.

4. The method for preparing a monolithic ceramic filter plate for dewatering low-grade iron ore concentrates according to claim 1, characterized in that, In the step 2), the adhesive is furan resin, and the density is 1.05-1.25 g / cm 3 .

5. The method of producing a monolithic ceramic filter plate for dewatering low-grade iron ore concentrates according to claim 1, characterized in that, In the step 2), the curing agent is a sulfonic acid curing agent, the density is 1-1.3 g / cm 3 , and the total acid amount is 31-35%.

6. The method for preparing the integral structure ceramic filter plate for dewatering low-grade iron concentrate according to claim 1, characterized in that, In step 6), the viscosity of polyvinyl alcohol is 20-25 mPa·s.

7. The method for preparing the integral structure ceramic filter plate for dewatering low-grade iron concentrate according to claim 1, characterized in that, In step 6), the alumina powder has a particle size distribution D50 of 3-5 μm; the clay is one or both of montmorillonite or kaolinite mineral clays, and the clay particle size is 5-8 μm.

8. The method of producing a monolithic ceramic filter plate for dewatering low-grade iron ore concentrates according to claim 1, characterized in that, In step 6), the pressure of the high-pressure atomizing spraying equipment is 0.45 to 0.6 MPa.

9. The integral structure ceramic filter plate obtained by the preparation method of the integral structure ceramic filter plate for dewatering low-grade iron concentrate according to any one of claims 1-8.

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