Ceramic recycling waste residue, ceramic brick green and preparation method thereof

Abstract

The present invention relates to the field of ceramic technology, and in particular to a ceramic recycling waste slag, ceramic brick blank and a preparation method thereof. The ceramic recycling waste slag, and its preparation method include the following steps: S10. Primary crushing and secondary crushing of the waste slag raw material to form fine particles with a particle size of less than 1 mm; S20. Primary magnetic separation and secondary magnetic separation and iron removal of the fine particles to reduce the iron content in the fine particles to less than 0.5%; S30. The fine particles are sequentially pickled, chelated to remove heavy metals and surface modified to obtain the recycled waste slag. After crushing, iron removal, pickling, chelated to remove heavy metals and surface modification, the recycled waste slag of the present invention can effectively reduce the impact on the quality of the brick blank, increase the use of waste slag in the brick blank, and improve the recycling rate. In addition, the present invention also optimizes the formula of the ceramic brick blank so that the high content of recycled waste slag will not reduce the performance of the ceramic brick blank.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramics, and in particular to a ceramic recycling waste residue, a ceramic brick and a preparation method thereof. Background Art

[0002] Currently, the waste residue generated during ceramic factory production primarily consists of gutter sediment, edge grinding residue, and polishing residue. Existing waste residue treatment primarily involves using a small amount as raw material for the production of low-end ceramic tiles. However, with product upgrades and the current sluggish market for low-end ceramics, the amount of waste residue used in green bodies is decreasing, leaving a significant amount of waste residue unrecyclable. Currently, the recycling rate for green body residue generally ranges from 3% to 6%, while the generation rate is 8% to 10%, far from achieving complete waste residue treatment.

[0003] In addition, the use of waste slag in the production of green bodies also brings various quality problems, such as: waste slag can easily cause defects such as prickly heat and pinholes on the surface of the product; the use of waste slag will cause the whiteness of the green body to decrease, affecting the appearance of the product and leading to reduced product quality; the use of waste slag will also cause the destructive strength of the green body after firing to decrease, affecting the scope of use and life.

[0004] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a ceramic recycling waste slag, ceramic brick blanks and their preparation method, aiming to increase the utilization rate of ceramic waste slag in ceramic brick blanks and reduce the negative impact of the use of ceramic waste slag on the quality of ceramic brick blanks.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a ceramic recycling waste residue, wherein the preparation method thereof comprises the following steps:

[0008] S10. The waste raw materials are subjected to primary and secondary crushing to form fine particles of less than 1 mm in size;

[0009] S20. The fine particles are subjected to primary magnetic separation and secondary magnetic separation to remove iron, so that the iron content in the fine particles is reduced to less than 0.5%;

[0010] S30. The fine particles are sequentially subjected to pickling, complexation and heavy metal removal, and surface modification to obtain the recycled waste residue;

[0011] The S30 includes the following steps:

[0012] S31. The waste residue fine particles are mixed with dilute hydrochloric acid at a concentration of 3 to 8%, and the reaction is carried out at 60 to 80 ° C for 1 to 2 hours;

[0013] S32. Adding a complexing agent to remove heavy metal ions and separating the precipitate;

[0014] S33. Modify the precipitate using a silane coupling agent to obtain recycled waste residue.

[0015] The ceramic waste slag recycling method, wherein during pickling, the mass ratio of the waste slag fine particles to the dilute hydrochloric acid is 1: (3-4).

[0016] The ceramic recycling waste residue, wherein the complexing agent is EDTA or citric acid.

[0017] The second aspect of the present invention provides a ceramic tile blank using recycled waste slag. The raw materials for its preparation include the following components, calculated by mass percentage: 6-10% original ore mud, 5-9% black mud, 3-6% calcined coal gangue, 18-24% potassium sodium stone powder, 15-21% sodium feldspar powder, 4-8% modified bentonite, 2-6% ultra-white sand, 2-4% diopside, 10-16% of the above-mentioned recycled ceramic waste slag, 1-3% waste brick particles, 3-7% quartz sand, 3-8% reinforcing agent, 0.5-1.5% zinc borate, and 1-3% whitening agent.

[0018] The ceramic brick blank using recycled waste residue, wherein the reinforcing agent includes nano-silicon dioxide and kaolin, and the mass ratio of the nano-silicon dioxide to kaolin is 1:(2-4).

[0019] The ceramic brick blank using recycled waste residue, wherein the modified bentonite is quaternary ammonium salt intercalation modified bentonite.

[0020] A third aspect of the present invention provides a method for preparing a ceramic tile blank, which is used to prepare the ceramic tile blank using the recycled waste residue as described above, comprising the following steps:

[0021] A01. Prepare the ingredients according to the formula, mix thoroughly, add water, ball-mill, and spray-dry to obtain a powder.

[0022] A02. The powder is pressed into a shape and dried to obtain a green body having a moisture content of 0.2 to 0.4%;

[0023] A03. Firing the green body to obtain the ceramic brick green body using recycled waste slag.

[0024] The method for preparing ceramic brick green body, wherein the firing of the green body comprises the following steps:

[0025] Low temperature stage: Place the green body into the kiln and raise the ambient temperature from room temperature to 300°C at a rate of 22-28°C / min, while controlling the humidity in the kiln to less than 30%RH.

[0026] Medium temperature stage: Raise the ambient temperature of the green body to 800℃ at a heating rate of 42-48℃ / min, and continuously introduce air into the kiln;

[0027] The first high temperature stage: the ambient temperature of the green body is raised to 1100°C at a heating rate of 42-48°C / min, and then kept at a constant temperature for 10 minutes;

[0028] The second high temperature stage: the ambient temperature of the green body is raised to 1250°C at a heating rate of 42-48°C / min, and then kept at a constant temperature for 5 minutes;

[0029] Slow cooling stage: reduce the ambient temperature of the green body to 800°C at a cooling rate of less than 20°C / min;

[0030] Rapid cooling stage: Turn on the air cooling to reduce the temperature of the blank at a rate of 50-80℃ / min.

[0031] The method for preparing ceramic tile blanks, wherein, during the firing of the blanks, when the ambient temperature of the blanks is 300-900°C, the pressure of the combustion-supporting air is controlled at 1.5-1.6 MPa; when the ambient temperature of the blanks is 900-1150°C, the pressure of the combustion-supporting air is controlled at 0.2-0.3 MPa; when the ambient temperature of the blanks is 1150-1250°C, the pressure of the combustion-supporting air is controlled at 0.7-0.8 MPa.

[0032] The method for preparing ceramic tiles, wherein the moisture content of the powder in A01 is 6-7%.

[0033] Beneficial effects: The first aspect of the present invention provides a ceramic recycling waste slag, which is obtained by subjecting the waste slag to crushing, magnetic separation, pickling, complexation to remove heavy metals and surface modification treatment in sequence, effectively removing some impurities therein, and improving the plasticity through surface modification, which can effectively reduce the adverse effects on the quality of brick greens, thereby improving the recycling rate.

[0034] The second aspect of the present invention is a ceramic tile blank using recycled waste slag. The ceramic tile blank increases the amount of ceramic recycled waste slag used in the formula by optimizing the formula, thereby increasing the recovery rate of the waste slag. In addition, by adopting components such as reinforcing agents, zinc borate and whitening agents, the quality problems of the product caused by the use of recycled waste slag, such as low destructive strength, prickly heat, pinhole defects and low whiteness, are solved.

[0035] The third aspect of the present invention provides a method for preparing ceramic brick blanks. The preparation method effectively reduces the occurrence of product defects by optimizing the temperature changes and oxygen content changes during the firing process, and makes the destructive strength of the product meet the use requirements, so that the ceramic waste residue can be recycled more and used in the production of mid-to-high-end products. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the product picture of Example 1.

[0037] Figure 2 This is the product picture of Comparative Example 1. DETAILED DESCRIPTION

[0038] The present invention provides a ceramic waste recycling residue, a ceramic tile blank, and a method for preparing the same. To make the objectives, technical solutions, and effects of the present invention more clear and explicit, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0039] A first aspect of the present invention provides a ceramic recycling waste residue, wherein the preparation method thereof comprises the following steps:

[0040] S10. The waste raw materials are subjected to primary and secondary crushing to form fine particles of less than 1 mm in size;

[0041] During primary crushing, a jaw crusher or impact crusher can be used to crush the waste slag raw materials into coarse particles with a particle size of less than 10mm and remove large impurities;

[0042] Secondary crushing is then performed using a cone crusher or roller press, further reducing coarse particles less than 10 mm to less than 1 mm. During this crushing process, incompletely crushed particles can be separated through a vibrating screen (with a mesh size of 0.5 to 1 mm) for secondary processing. This finer particle size increases the surface area of the waste slag, making it easier to remove iron and other impurities later.

[0043] S20. The fine particles are subjected to primary magnetic separation and secondary magnetic separation to remove iron, so that the iron content in the fine particles is reduced to less than 0.5%;

[0044] During primary magnetic separation and iron removal: a permanent magnetic drum magnetic separator (magnetic field strength ≥ 0.8T) can be used to perform dry magnetic separation on fine-grained waste slag to remove large-particle ferromagnetic materials;

[0045] In the secondary magnetic separation to remove iron, a high gradient magnetic separator (magnetic field strength 1.2 ~ 1.5T) can be used for wet magnetic separation to separate micron-sized iron oxides (such as Fe2O3, Fe3O4).

[0046] S30. The fine particles are sequentially subjected to acid washing, complexation to remove heavy metals, and surface modification treatment to obtain the recycled waste residue.

[0047] Acid pickling can dissolve free metals and oxide impurities such as calcium and aluminum in fine-grained waste slag, preventing the recycled waste slag from melting and volatilizing during sintering to form pore defects.

[0048] Preferably, the pickling can be performed by the following steps: mixing the waste residue with dilute hydrochloric acid having a concentration of 3-8% in a reactor, with the mass ratio of the waste residue to the dilute hydrochloric acid being 1:(3-4), and then stirring the reaction at 60-80°C for 1-2 hours to fully dissolve free metals and oxide impurities such as calcium and aluminum.

[0049] Preferably, the complexation removal of heavy metals can be carried out by the following steps: adding a complexing agent to the recycled material after pickling to complex the heavy metal ions (such as Pb 2+ 、Cd 2+ ), after forming a stable complex, it is removed by centrifugation to obtain a precipitate;

[0050] Preferably, the complexing agent is EDTA or citric acid, and the added amount is 0.5 to 1.5% of the dry mass of the recycled material after acid washing.

[0051] In surface modification: Silane coupling agent (KH-550 or KH-570) can be used to coat the surface of the waste residue (addition amount 0.2-0.5%) to improve its interfacial bonding strength with the binder and increase plasticity, thereby obtaining recycled waste residue.

[0052] Through the three-step method of "pickling-complexation-modification", the heavy metal content in the waste slag can be reduced to ≤50ppm (in line with GB5085.3-2007 standard), and the hydroxyl (-OH) active sites on the surface of the waste slag can be increased, which promotes sintering densification, ensures the density of the green body in subsequent firing, and increases the strength of the green body.

[0053] The second aspect of the present invention provides a ceramic tile blank using recycled waste slag. The raw materials for its preparation include the following components, calculated by mass percentage: 6-10% original ore mud, 5-9% black mud, 3-6% calcined coal gangue, 18-24% potassium sodium stone powder, 15-21% sodium feldspar powder, 4-8% modified bentonite, 2-6% ultra-white sand, 2-4% diopside, 10-16% recycled ceramic waste slag, 1-3% waste brick particles, 3-7% quartz sand, 3-8% reinforcing agent, 0.5-1.5% zinc borate, and 1-3% whitening agent.

[0054] Specifically, the raw materials for preparing the ceramic bricks further include a dispersant, and the amount of the dispersant added is 0.15 to 0.3% of the sum of the masses of the above components.

[0055] Among the above components, zinc borate acts as a bubble inhibitor, decomposing at 800-1000°C to generate B2O3, which covers the surface of the waste slag particles, inhibits the oxidation of elements such as Fe and Ca to release gases, and can inhibit the escape of sintering gases at high temperatures, avoiding the occurrence of prickly heat and pinhole defects.

[0056] Whitening powder is used to compensate for the color influence of waste slag. Specifically, titanium dioxide (particle size is 0.5 to 1 micron) can be used. The high refractive index characteristics of titanium dioxide can compensate for the grayish tones of waste slag and make the whiteness of the blank ≥85%.

[0057] Under the synergistic effect of zinc borate and whitening powder, the problems of brick surface defects and insufficient whiteness caused by the use of high-content recycled waste slag can be effectively solved.

[0058] The reinforcing agent is used to improve the strength performance of the green body. Preferably, the reinforcing agent includes nano-silica and kaolin, and the mass ratio of the nano-silica to kaolin is 1:(2-4). Furthermore, the particle size of the nano-silica is 20-50 nm, which is used to fill the micropores of the green body. Nano-silica enhances the bonding force between particles through the "nano effect" and reduces sintering shrinkage stress. However, the amount of nano-silica should not be too much, otherwise it is easy to form agglomerates, and the coordination with kaolin can avoid the agglomeration problem. In addition, kaolin can also provide an aluminum source, which generates mullite phase (3Al2O3·2SiO2) with SiO2 in the waste slag at high temperature, significantly improving the compressive strength of the green body (≥15MPa).

[0059] Preferably, the modified bentonite is quaternary ammonium salt intercalated modified bentonite. The sodium bentonite treated with quaternary ammonium salt intercalation has its interlayer spacing expanded to 1.5-2.0 nm, which improves the adsorption capacity and can reduce cracking caused by water evaporation.

[0060] By optimizing the formulation, the present invention solves the problem of glaze rashes and pinhole defects easily caused by the use of waste residue. The whiteness of the green body after using the waste residue is not affected by the waste residue, and high-quality ceramic production can still be achieved, thus solving the problem of product quality decline caused by the use of waste residue. The waste residue in the overall formulation can be fully recycled, achieving zero pollution and zero waste.

[0061] A third aspect of the present invention provides a method for preparing a ceramic tile blank, which is used to prepare the ceramic tile blank using the recycled waste residue as described above, comprising the following steps:

[0062] A01. Prepare the ingredients according to the formula, mix thoroughly, add water, ball-mill, and spray-dry to obtain a powder.

[0063] A02. The powder is pressed into a shape and dried to obtain a green body having a moisture content of 0.2 to 0.4%;

[0064] A03. Firing the green body to obtain the ceramic brick green body using recycled waste slag.

[0065] The preparation method of the above ceramic brick is as follows:

[0066] The components are mixed uniformly, and then 38-40 wt% of water is added and ball milled to obtain a slurry with a moisture content of 35-38%, a flow rate of 30-60 s / 100 mL, and a specific gravity of 1.70-1.75 g / mL; the slurry is spray-dried to form a powder with a moisture content of 6.0-7.0%;

[0067] The powder is pressed into a green body of required specifications and thickness using a stamping press or a rolling press. After drying and draining, the moisture content of the green body is between 0.2 and 0.4%, and the strength of the dried green body is 1.8 to 2.5 MPa.

[0068] The dried body can be fired directly, or it can be further sent to glazing equipment and pattern printing equipment to make a blank. After the pattern is printed, the brick body enters the firing stage.

[0069] Preferably, the firing of the green body comprises the following steps:

[0070] Low-temperature stage: The green body is placed in the kiln and the ambient temperature is raised from room temperature to 300°C at a rate of 22-28°C / min. The humidity in the kiln is controlled to be less than 30%RH. During the low-temperature stage, residual moisture and free water in the green body are slowly discharged to prevent cracking caused by steam pressure.

[0071] Medium-temperature stage: The ambient temperature of the green body is raised to 800°C at a heating rate of 42-48°C / min, and air is continuously introduced into the kiln. During the medium-temperature stage, increasing the heating rate can accelerate the oxidation and decomposition of organic binders (such as bentonite) and residual organic matter in the waste slag. By introducing air (oxygen concentration ≥ 20%), the complete combustion of gases such as CO and VOCs is promoted, reducing carbon deposition and thus reducing surface defects caused by outgassing of the green body.

[0072] The first high-temperature stage: The ambient temperature of the green body is raised to 1100°C at a heating rate of 42-48°C / min, and then kept constant for 10 minutes. At 800-1100°C, SiO2 and Al2O3 in the waste slag gradually react with kaolin to form mullite phase (3Al2O3·2SiO2), forming a skeleton structure.

[0073] The second high-temperature stage: The ambient temperature of the green body is raised to 1250°C at a rate of 42-48°C / min, and then kept constant for 5 minutes. Within this temperature range, the nano-silica melts to form a glass phase, filling the grain boundary pores and achieving liquid phase sintering densification.

[0074] The temperature range of the first high temperature stage and the second high temperature stage ensures the formation of mullite crystal phase and glass phase, fills the gaps between crystals, increases the strength of the product, and ensures that the strength of the fired brick is above 40Mpa;

[0075] Slow cooling stage: The ambient temperature of the green body is lowered to 800°C at a cooling rate of less than 20°C / min to avoid microcracks caused by rapid shrinkage of the glass phase;

[0076] Rapid cooling stage: Turn on air cooling to reduce the temperature of the billet at a rate of 50-80°C / min to inhibit excessive grain growth.

[0077] The design of the cooling curve can effectively prevent the generation of internal stress in the product and ensure the strength of the product.

[0078] Preferably, during the firing of the green body, 300-900°C is the oxidation stage. When the ambient temperature of the green body is 300-900°C, the pressure of the combustion-supporting air is controlled at 1.5-1.6 MPa. By increasing the air volume to ensure sufficient oxygen content, the organic matter can be completely decomposed, and Fe 2+ Oxidized to Fe 3+ , reduce the risk of blackening due to high temperature reduction;

[0079] 900~1150℃ is the weak reduction stage. When the ambient temperature of the green body is 900~1150℃, the pressure of the combustion-supporting air is controlled at 0.2~0.3MPa. By reducing the amount of air input, it is ensured that part of the CO mixed gas (CO content is 5~8%) is generated during the combustion of the fuel, and part of the Fe 3+ Reduction to Fe 2+ , reducing the negative impact of Fe on whiteness, while avoiding excessive reduction causing the green body to turn gray.

[0080] 900-1150℃ is the neutral atmosphere stage. When the ambient temperature of the green body is 1150-1250℃, the pressure of the combustion-supporting air is controlled at 0.7-0.8MPa to inhibit the oxidation or reduction of iron ions and stabilize the mineral phase structure.

[0081] By switching between the three-stage atmosphere of "oxidation-reduction-neutral", the valence state of variable valence elements such as Fe and Ti can be controlled, and the color development of color centers (such as Fe 3+ The yellow spots caused by the Fe2O3 coating were eliminated), which improved the whiteness of the green body to ≥40% (ISO 2470) and reduced the Fe2O3 color rendering effect by 60%.

[0082] The bricks of the present invention utilize a stepped heating curve for firing, unlike the rapid firing curves used in current ceramic products. This process utilizes strict control over the firing rates of the low-temperature dehydration phase, the medium-temperature oxidative decomposition phase, the high-temperature firing phase, and the cooling phase. This firing curve facilitates degassing during firing, preventing surface defects such as prickly heat and pinholes.

[0083] The present application is further described below with reference to specific embodiments.

[0084] Example 1

[0085] A ceramic tile blank made of recycled waste residue, comprising the following components by weight: 8 parts of raw ore mud, 7 parts of black mud, 4.5 parts of calcined coal gangue, 21 parts of potassium sodium stone powder, 18 parts of sodium feldspar powder, 6 parts of modified bentonite, 4 parts of ultra-white sand, 3 parts of diopside, 13 parts of recycled ceramic waste residue, 2 parts of waste brick particles, 5 parts of quartz sand, 5.5 parts of reinforcing agent, 1 part of zinc borate, 2 parts of whitening agent, and 0.2 part of dispersant;

[0086] Wherein, the preparation method of the recycled waste residue is as follows:

[0087] S10. Primary and secondary crushing of the waste residue raw materials;

[0088] During the primary crushing, a jaw crusher is used to crush the waste slag raw materials into coarse particles with a particle size of less than 10mm and remove large impurities;

[0089] Then, a cone crusher is used for secondary crushing to further refine the coarse particles with a size of less than 10 mm to less than 1 mm;

[0090] S20. The fine particles are subjected to primary magnetic separation and secondary magnetic separation for iron removal;

[0091] During primary magnetic separation and iron removal: a permanent magnetic drum magnetic separator (magnetic field strength ≥ 0.8T) is used to perform dry magnetic separation on fine-grained waste slag to remove large-particle ferromagnetic materials;

[0092] In the secondary magnetic separation, a high gradient magnetic separator (magnetic field strength 1.5T) is used for wet magnetic separation to separate micron-sized iron oxides (such as Fe2O3 and Fe3O4);

[0093] S30. The fine particles are sequentially subjected to acid washing, complexation to remove heavy metals, and surface modification treatment;

[0094] The pickling process is as follows: the waste slag fine particles are mixed with 8% dilute hydrochloric acid in a reaction kettle at a mass ratio of 1:3, and then stirred at 70°C for 1.5 hours to fully dissolve free metals and oxide impurities such as calcium and aluminum;

[0095] The following steps are used to remove heavy metals by complexation: add complexing agent EDTA to the recycled material after pickling, and the addition amount is 1.5% of the dry mass of the recycled material after pickling to complex heavy metal ions (such as Pb 2+ 、Cd 2+ ), after forming a stable complex, it is removed by centrifugation to obtain a precipitate;

[0096] The surface modification adopts the following steps: using a silane coupling agent (KH-550) to coat the surface of the precipitate (the addition amount is 0.4%) to obtain the recycled waste residue;

[0097] In this embodiment, the reinforcing agent is a composite of nano-silicon dioxide and kaolin in a mass ratio of 1:3;

[0098] The whitening agent is titanium dioxide;

[0099] The dispersant is a polycarboxylic acid dispersant;

[0100] The modified bentonite is sodium bentonite treated with quaternary ammonium salt intercalation;

[0101] The method for preparing the ceramic tile comprises the following steps:

[0102] The components were mixed evenly, and then 38 wt% of water was added, ball milled, and spray dried to obtain a powder with a moisture content of 6.5%.

[0103] The powder is pressed into shape, dried and drained, and the moisture content of the dried green body is 0.3%;

[0104] After drying, the bricks are printed with patterns and glazed, and then fired to produce ceramic bricks made of recycled waste residue.

[0105] The bricks enter the roller kiln for firing, and the firing curve is as follows:

[0106] Low temperature stage: Place the green body into the kiln and raise the ambient temperature from room temperature to 300°C at a rate of 25°C / min. The humidity in the kiln is controlled to be less than 30%RH.

[0107] Medium temperature stage: Raise the ambient temperature of the green body to 800℃ at a heating rate of 45℃ / min, and continuously introduce air into the kiln to ensure that the oxygen concentration is ≥20%;

[0108] The first high-temperature stage: the ambient temperature of the green body is raised to 1100°C at a heating rate of 45°C / min, and then kept at this temperature for 10 minutes;

[0109] The second high temperature stage: the ambient temperature of the green body is raised to 1250 ° C at a heating rate of 45 ° C / min, and then kept at a constant temperature for 5 minutes;

[0110] Slow cooling stage: reduce the ambient temperature of the green body to 800°C at a cooling rate of less than 20°C / min;

[0111] Rapid cooling stage: Turn on the air cooling to reduce the temperature of the blank at a rate of 50-80℃ / min;

[0112] During the above firing process, when the ambient temperature of the green body is 300-900°C, the pressure of the combustion-supporting air is controlled at 1.5MPa; when the ambient temperature of the green body is 900-1150°C, the pressure of the combustion-supporting air is controlled at 0.3MPa; when the ambient temperature of the green body is 1150-1250°C, the pressure of the combustion-supporting air is controlled at 0.8MPa.

[0113] Example 2

[0114] A ceramic tile blank using recycled waste slag is different from Example 1 in that the amount of recycled waste slag used is 10 parts, and relative to Example 1, the amount of calcined coal gangue is increased by 2 parts, and the amount of albite is increased by 1 part.

[0115] Example 3

[0116] A ceramic tile blank using recycled waste slag is different from Example 1 in that the amount of recycled waste slag used is 16 parts, and compared with Example 1, the amount of calcined coal gangue is reduced by 2 parts and the amount of albite is reduced by 1 part.

[0117] Example 4

[0118] A ceramic brick blank using recycled waste residue is different from Example 1 in that the amount of modified bentonite used is 4 parts, and the amount of black mud is increased by 2 parts relative to Example 1.

[0119] Example 5

[0120] A ceramic brick blank using recycled waste residue, which differs from Example 1 in that the amount of modified bentonite used is 8 parts, and the amount of black mud is reduced by 2 parts relative to Example 1.

[0121] Example 6

[0122] A ceramic tile blank using recycled waste residue is different from Example 1 in that the amount of reinforcing agent used is 3 parts, and the amount of black mud is increased by 2.5 parts relative to Example 1.

[0123] Example 7

[0124] A ceramic brick blank using recycled waste residue is different from Example 1 in that the amount of reinforcing agent used is 8 parts, and relative to Example 1, the amount of black mud is reduced by 1.5 parts, and the amount of modified bentonite is reduced by 1 part.

[0125] Example 8

[0126] A ceramic tile blank using recycled waste residue is different from Example 1 in that the amount of zinc borate used is 0.5 parts, and relative to Example 1, the amount of quartz sand is increased by 0.5 parts.

[0127] Example 9

[0128] A ceramic tile blank using recycled waste residue is different from Example 1 in that the amount of zinc borate used is 1.5 parts, and the amount of quartz sand is reduced by 0.5 parts relative to Example 1.

[0129] Comparative Example 1

[0130] A ceramic tile blank using recycled waste residue, which differs from Example 1 in that ordinary waste residue that has not been subjected to crushing, iron removal, pickling, chelation and surface modification treatments is used to replace the recycled waste residue.

[0131] Comparative Example 2

[0132] A ceramic tile blank using recycled waste residue differs from Example 1 in that the firing curve is different. This comparative example adopts a conventional firing curve in the prior art, which is as follows:

[0133] Front temperature zone: 60℃~450℃, heating rate is 39℃ / min;

[0134] Medium temperature zone: 450℃~1110℃, heating rate is 65℃ / min;

[0135] High temperature zone: 1110℃~1185℃, heating rate is 25℃ / min;

[0136] High insulation zone: 1185℃, insulation for 5min;

[0137] Cooling stage: 1185℃~150℃, cooling rate: 103.5℃ / min.

[0138] Comparative Example 3

[0139] A ceramic brick blank using recycled waste residue is different from Example 1 in that the amount of modified bentonite used is 2 parts, and relative to Example 1, the amount of calcined coal gangue is increased by 2 parts, and the amount of black mud is increased by 2 parts.

[0140] Comparative Example 4

[0141] A ceramic brick blank using recycled waste residue is different from Example 1 in that the amount of modified bentonite used is 10 parts, and relative to Example 1, the amount of calcined coal gangue is reduced by 2 parts, and the amount of black mud is reduced by 2 parts.

[0142] Comparative Example 5

[0143] A ceramic tile blank using recycled waste slag, which differs from Example 1 in that the amount of reinforcing agent used is 1 part, and relative to Example 1, the amount of original ore mud is increased by 2 parts, the amount of potassium and sodium feldspar is increased by 1 part, and the amount of super white sand is increased by 1.5 parts.

[0144] Comparative Example 6

[0145] A ceramic tile blank using recycled waste residue differs from Example 1 in that the amount of reinforcing agent used is 10 parts, and relative to Example 1, the amount of original ore mud is reduced by 2 parts, the amount of potassium-sodium feldspar is reduced by 1 part, and the amount of super-white sand is reduced by 1.5 parts.

[0146] Comparative Example 7

[0147] A ceramic tile blank using recycled waste residue is different from Example 1 in that the amount of zinc borate used is 0 part, and the amount of quartz sand is increased by 1 part relative to Example 1.

[0148] Comparative Example 8

[0149] A ceramic tile blank using recycled waste residue is different from Example 1 in that the amount of zinc borate used is 3 parts, and the amount of quartz sand is reduced by 2 parts relative to Example 1.

[0150] Comparative Example 9

[0151] A ceramic tile blank using recycled waste residue is different from Example 1 in that the waste residue used is only subjected to crushing and iron removal treatments but not to pickling, complexation and surface modification treatments.

[0152] Comparative Example 10

[0153] A ceramic tile blank using recycled waste residue is different from Example 1 in that the waste residue used has been subjected to pickling, complexation and surface modification treatments, but has not been subjected to crushing or iron removal treatments.

[0154] Comparative Example 11

[0155] A ceramic tile blank using recycled waste residue is different from Example 1 in that the waste residue used has only been subjected to crushing, iron removal and pickling, but has not been subjected to chelation and surface modification treatment.

[0156] Comparative Example 12

[0157] A ceramic tile blank using recycled waste residue is different from Example 1 in that the waste residue used has only been subjected to crushing, iron removal, chelation and surface modification treatments, but has not been subjected to acid washing.

[0158] The strength of the green and ceramic tile products prepared in the above examples and comparative examples was tested using the following test method:

[0159] Cut a standard specimen, place it horizontally on two supporting rollers, apply load in the middle until it breaks, and calculate the flexural strength: R=3FL / 2bh 2 (F is the breaking load, L is the span, b and h are the width and thickness of the specimen).

[0160] Method for detecting the whiteness of the green body: measure with a digital whiteness meter.

[0161] Detection method for glaze prickles and pinholes: Stand 1m away from the sample product and visually inspect the shape and number of defects.

[0162] The test results are as follows:

[0163]

[0164] Examples 1-9 are products made according to the formula and preparation method of the present invention. From the test results, it can be seen that the green strength can reach above 1.85 MPa, the finished product strength can reach above 43 MPa, and the whiteness can reach above 54 GU, which meets the use requirements of high-quality ceramic tiles. Figure 1 This is a product picture of Example 1. It can be seen that the glaze surface has no defects such as raised prickly heat and pinholes.

[0165] In Comparative Example 1, the waste residue was not subjected to crushing, magnetic separation, pickling, complexation and surface modification treatments. The waste residue had low plasticity, resulting in low green strength and easy product breakage. The fired bricks had low breaking strength and low flexural strength. Figure 2 Because there are many organic matters in the waste slag, there is more exhaust during firing, which makes the glaze surface have more defects such as pinholes and prickly heat. Since the iron content of the waste slag in Comparative Example 1 is high, the whiteness of the brick is also affected.

[0166] In Comparative Example 2, a conventional firing curve was used. However, due to the high amount of waste residue and the inappropriate firing curve, less mullite crystals were formed, resulting in low strength of the finished product. Furthermore, poor control of the redox atmosphere led to poor whiteness of the green body. Furthermore, an inappropriate firing rate resulted in poor exhaust, affecting the product surface and causing numerous defects.

[0167] In Comparative Example 3, the amount of modified bentonite used is relatively small. Modified bentonite has the function of optimizing green strength. When the amount of modified bentonite used is relatively small, the green strength will be relatively low and the yield rate will be relatively low.

[0168] In Comparative Example 4, the amount of modified bentonite used is large, and the green body strength is better. However, due to the large amount of bentonite used, the whiteness of the green body is reduced. At the same time, due to the excessive use of bentonite, it is difficult to exhaust during the firing of the green body, which affects the defects of the glaze and causes more defects.

[0169] In Comparative Example 5, the amount of reinforcing agent used is relatively small, which directly affects the strength of the green body and the strength of the finished product.

[0170] In Comparative Example 6, the amount of reinforcing agent used was relatively large, resulting in agglomeration, which directly affected the flexural strength of the finished product after firing and affected its performance.

[0171] In Comparative Example 7, no bubble inhibitor was used, resulting in a large amount of bubbles during firing, which caused the strength of the finished product to be low. In addition, since the degassing of the body could not be suppressed, more glaze defects were caused.

[0172] In Comparative Example 8, due to the large amount of bubble inhibitor used, the ZnO formed after the decomposition of the bubble inhibitor itself has the effect of lowering the formulation temperature, affecting the flexural strength and whiteness of the body, and causing over-firing, affecting the quality of the glaze and causing more defects.

[0173] The waste slag recovered in Comparative Example 9 was not treated by the three-step method of "pickling, complexation and surface modification". There were more impurities in the waste slag, which resulted in many glaze defects after firing and low strength of the finished product. In addition, since the waste slag was not surface modified, the green body strength was low and the yield was low.

[0174] The waste slag recovered in Comparative Example 10 was not crushed and iron removed, resulting in larger particles, smaller surface energy, and lower green strength, which resulted in a low yield. Furthermore, iron was not removed, resulting in a low whiteness after firing.

[0175] The waste residue recovered in Comparative Example 11 was not subjected to complexation and surface modification, resulting in low green strength and affecting the yield of the product.

[0176] The waste residue recovered in Comparative Example 12 was not pickled, which mainly affected the whiteness of the product after firing. In addition, it contained more decomposable substances and elemental metals, which formed more prickly heat and pinhole defects after firing.

[0177] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A ceramic tile green body made from recycled ceramic waste, characterized in that: The raw materials for its preparation include the following components, calculated by mass percentage: 6-10% of raw ore mud, 5-9% of black mud, 3-6% of calcined coal gangue, 18-24% of potassium sodium stone powder, 15-21% of sodium feldspar powder, 4-8% of modified bentonite, 2-6% of ultra-white sand, 2-4% of diopside, 10-16% of recycled ceramic slag, 1-3% of waste brick particles, 3-7% of quartz sand, 3-8% of reinforcing agent, 0.5-1.5% of zinc borate, and 1-3% of whitening agent; the reinforcing agent includes nano-silica and kaolin, and the mass ratio of the nano-silica to kaolin is 1:(2-4); the modified bentonite is quaternary ammonium salt intercalation modified bentonite; The preparation method of the ceramic recycling waste residue comprises the following steps: S10. The waste raw materials are subjected to primary and secondary crushing to form fine particles of less than 1 mm in size; S20. The fine particles are subjected to primary magnetic separation and secondary magnetic separation to remove iron, so that the iron content in the fine particles is reduced to less than 0.5%; S30. The fine particles are sequentially pickled, complexed to remove heavy metals, and surface modified to obtain the ceramic waste residue recovery; The S30 includes the following steps: S31. The waste residue fine particles are mixed with dilute hydrochloric acid at a concentration of 3 to 8%, and the reaction is carried out at 60 to 80 ° C for 1 to 2 hours; S32. Adding a complexing agent to remove heavy metal ions and separating the precipitate; S33. Modify the precipitate using a silane coupling agent to obtain ceramic recycling waste residue.

2. The ceramic brick green using recycled ceramic waste according to claim 1, characterized in that: During pickling, the mass ratio of waste slag fine particles to dilute hydrochloric acid is 1: (3~4).

3. The ceramic brick green using recycled ceramic waste according to claim 1, characterized in that: The complexing agent is EDTA or citric acid.

4. A method for preparing a ceramic tile, characterized in that: The method for preparing a ceramic brick green body using recycled ceramic waste as claimed in any one of claims 1 to 3 comprises the following steps: A01. Prepare the ingredients according to the formula, mix thoroughly, add water, ball-mill, and spray-dry to obtain a powder. A02. The powder is pressed into a shape and dried to obtain a green body having a moisture content of 0.2 to 0.4%; A03. The green body is fired to obtain a ceramic tile using recycled ceramic waste; The firing of the green body comprises the following steps: Low temperature stage: Place the green body into the kiln and raise the ambient temperature from room temperature to 300°C at a rate of 22-28°C / min, while controlling the humidity in the kiln to less than 30%RH. Medium temperature stage: Raise the ambient temperature of the green body to 800℃ at a heating rate of 42-48℃ / min, and continuously introduce air into the kiln; The first high temperature stage: the ambient temperature of the green body is raised to 1100°C at a heating rate of 42-48°C / min, and then kept at a constant temperature for 10 minutes; The second high temperature stage: the ambient temperature of the green body is raised to 1250°C at a heating rate of 42-48°C / min, and then kept at a constant temperature for 5 minutes; Slow cooling stage: reduce the ambient temperature of the green body to 800°C at a cooling rate of less than 20°C / min; Rapid cooling stage: Turn on the air cooling to reduce the temperature of the blank at a rate of 50-80℃ / min.

5. The method for preparing a ceramic tile according to claim 4, wherein: During the firing of the green body, when the ambient temperature of the green body is 300-900°C, the pressure of the combustion-supporting air is controlled at 1.5-1.6 MPa; when the ambient temperature of the green body is 900-1150°C, the pressure of the combustion-supporting air is controlled at 0.2-0.3 MPa; when the ambient temperature of the green body is 1150-1250°C, the pressure of the combustion-supporting air is controlled at 0.7-0.8 MPa.

6. The method for preparing a ceramic tile according to claim 4, wherein: In the A01, the moisture content of the powder is 6-7%.

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