A method for preparing waste clay sintered brick based on SA / R value

Abstract

The application discloses a kind of preparation methods of waste clay sintered brick based on SA / R value.Method includes: adding additive to waste clay to obtain mixed raw materials, the mass percentage of refractory component and fluxing component in mixed raw materials is calculated, and then the SA / R value of mixed raw materials is obtained, after constructing fitting formula and selecting sintered brick auxiliary material, the mass percentage of refractory component and fluxing component in sintered brick auxiliary material is obtained by chemical composition detection, then the target SA' / R' value of mixed raw materials after adding sintered brick auxiliary material is calculated according to fitting formula, and then the incorporation percentage of sintered brick auxiliary material is obtained, finally sintered brick is prepared by mixing sintered brick auxiliary material, waste clay and additive.The application method can make full use of the effective components of raw materials, so that the sintered product can obtain better strength grade, and the operation is simple and convenient.

Description

Technical Field

[0001] This invention relates to the field of inorganic solid waste resource utilization technology, specifically to a method for preparing waste clay sintered bricks based on SA / R values. Background Technology

[0002] Waste clay refers to construction waste generated during building operations in coastal and riverine areas. It mainly includes slag and mud from the construction of various infrastructure, industrial, and civil buildings, as well as river and lake silt from dredging operations. The production volume of this type of waste clay is enormous; my country generates approximately 2 billion tons of construction slag annually, and the production of construction mud exceeded 80 million tons in 2018 alone. Currently, the main disposal method is landfilling, which poses problems such as occupying land resources and impacting the environment. Therefore, the resource utilization of waste clay is particularly necessary and urgent. Waste clay is characterized by fine particles, high clay content, and high silica and aluminum content, and its material basis has the potential for producing sintered bricks.

[0003] my country has a long history of producing and applying sintered bricks. Traditionally, clay is the main raw material for sintered bricks, and their production consumes a large amount of high-quality clay resources. To address this issue, scholars have actively conducted research on producing sintered bricks using waste clay as the main raw material, achieving significant results and realizing the goal of sintered brick production. However, currently, many factories typically select auxiliary materials and their dosages based on experience, lacking theoretical guidance, making it difficult to guarantee the quality of the finished product. How to scientifically select and adjust the proportions of auxiliary materials for sintered bricks has become a challenge. While there are existing patents related to the proportions of raw materials for sintered bricks, they have the following limitations:

[0004] 1. The raw material formulation ratios fluctuate significantly and lack precision. Currently, many patents provide raw material formulations in the form of ranges, which cannot be scientifically determined. The determination of the ratios is somewhat arbitrary and often leads to large fluctuations in product quality. For example, patent CN111099879A, "A Waste Material Sintered Brick and Its Preparation Method," mentions 55-65 parts coal gangue, 20-30 parts shale, 10-20 parts sludge, and 8-15 parts water.

[0005] 2. The selection of auxiliary materials is not scientifically sound. For example, patent CN111175333, "A Method for Rapid Analysis and Compound Control of Construction Waste Soil Components", only states that the amount of auxiliary materials added is 5-20%, and the types include fly ash, ceramic glaze residue, waste brick powder, sawdust, slag, vitrified microspheres, silt, and slag, etc. However, it does not explain how to scientifically select the types of auxiliary materials and the amount of auxiliary materials added, and the performance of the raw materials is not fully utilized.

[0006] 3. Poor technical feasibility. For example, patent CN111175333, "A method for rapid analysis and compounding control of the composition of construction waste soil", monitors and compares the chemical composition, particle size, specific surface area, plasticity index, etc. of soil and gives the range of various indicators. However, it is difficult to meet the various indicators at the same time, the formula adjustment is inflexible, and the actual operation is difficult.

[0007] 4. Limited Scope of Application. Currently published patents mainly target single raw materials, and their research results cannot be applied to raw materials from different sources and with different compositions. For example, patent CN102491723, "A Stone-Clay Sintered Brick and Its Production Method," only relates to one type of sintered brick made from stone clay; CN102491724, "An Iron Ore Slag Sintered Brick and Its Production Method," only relates to one type of sintered brick made from iron ore slag.

[0008] Studies have shown that the main strength of sintered bricks comes from the solid solutions, eutectics, mixed crystals and new minerals formed by the refractory components (SiO2, Al2O3) and fluxing components (CaO, Fe2O3, MgO, K2O, Na2O) under high temperature conditions. The liquid phase formed at high temperature fills the pores and forms a glassy phase after cooling, which binds the insoluble particles to form a solid solution with high strength. Summary of the Invention

[0009] To address the problems in the background art, this invention provides a method for preparing sintered bricks from waste clay based on the SA / R value. This method solves the problem of adjusting the proportions of waste clay from different sources and compositions when preparing sintered bricks, enhancing its operability for industrial application, better realizing the resource utilization of waste clay, and producing sintered bricks with excellent performance indicators.

[0010] The technical solution adopted in this invention is:

[0011] The method includes the following steps:

[0012] 1) For sintered bricks, the required additives are added to waste clay to obtain a mixed raw material. The chemical composition of the mixed raw material is analyzed and the mass percentage of refractory components in the mixed raw material is calculated. and mass percentage of fluxing components And based on the mass percentage of refractory components in the mixed raw materials. and mass percentage of fluxing components The SA / R value of the mixed raw materials was calculated;

[0013] 2) Construct a fitting formula based on the relationship between the SA / R value of the mixed raw materials and the compressive strength of sintered bricks. Then, based on the actual required compressive strength of the sintered bricks, select the sintered brick additives to be added to the mixed raw materials using the SA / R value of the mixed raw materials in the fitting formula. Finally, calculate the target strength of the mixed raw materials after adding the sintered brick additives using the fitting formula. value;

[0014] 3) Conduct chemical composition analysis on the sintered brick auxiliary materials and calculate the mass percentage of refractory components in the sintered brick auxiliary materials. and mass percentage of fluxing components ;

[0015] 4) According to the above , , , The target of the mixed raw materials after adding sintered brick auxiliary materials The value is used to calculate the percentage of additives used in sintered bricks;

[0016] 5) According to the percentage of sintered brick auxiliary materials, waste clay and additives are mixed and aged, and then shaped, dried and fired to prepare waste clay sintered bricks.

[0017] In step 1), the waste clay is clay waste generated during the basic engineering and river dredging construction. The waste clay includes clay minerals with a mass content of 20-60%, clay particles with a mass content of 15-45% and a particle size of 0-0.002mm.

[0018] In step 1), the mass percentage of the refractory component Calculate using the following formula:

[0019]

[0020] in, This indicates the mass percentage of the refractory component in the mixed raw materials; Indicates the mass fraction; It is silicon dioxide. It is aluminum oxide;

[0021] Mass percentage of fluxing components Calculate using the following formula:

[0022]

[0023] in, This indicates the mass percentage of the fluxing component in the mixed raw materials; It is calcium oxide. Ferric oxide It is magnesium oxide. It is potassium oxide. It is sodium oxide.

[0024] In step 1), the mass percentage of the refractory component in the mixed raw materials is... and mass percentage of fluxing components The ratio of the two components is used as the SA / R value of the mixed raw materials, and is calculated according to the following formula:

[0025]

[0026] Where S represents silicon dioxide in the refractory component, A represents aluminum oxide in the refractory component, and R represents calcium oxide (CaO), ferric oxide (Fe2O3), magnesium oxide (MgO), potassium oxide (K2O), and sodium oxide (Na2O) in the fluxing component. This indicates the quality fraction.

[0027] In step 2), the fitting formula for the relationship between the SA / R value of the mixed raw materials and the compressive strength of the sintered bricks is as follows:

[0028]

[0029] Where P represents the compressive strength of sintered bricks without added sintering brick additives. This indicates the SA / R value of the mixed raw materials.

[0030] The sintered brick additives selected for inclusion in the mixed raw materials are as follows:

[0031] When the SA / R value is less than 4.6, select sintered brick auxiliary materials with an SA / R value greater than 4.6. The sintered brick auxiliary materials with an SA / R value greater than 4.6 are either fly ash or shale.

[0032] When the SA / R value is greater than 4.6, select sintered brick auxiliary materials with an SA / R value less than 4.6. The sintered brick auxiliary materials with an SA / R value less than 4.6 are either fly ash or steel slag.

[0033] In step 2), the target of mixing the raw materials after adding sintered brick auxiliary materials is... The value is obtained by inversely calculating using the following fitting formula, specifically:

[0034]

[0035] in, This indicates the actual required compressive strength of the sintered brick. This indicates the target of the mixed raw materials after adding sintered brick additives. value;

[0036] In step 3), after chemical composition analysis of the sintered brick auxiliary materials, the mass percentage of refractory components in the sintered brick auxiliary materials is determined. According to the mass percentage of the refractory component in the mixed raw materials in step 1), Calculated in the same way, the mass percentage of fluxing components in sintered brick auxiliary materials According to the mass percentage of fluxing components in the mixed raw materials in step 1). Calculated in the same way.

[0037] In step 4), the percentage of sintered brick additives is obtained by processing it as follows:

[0038]

[0039] in, This indicates the percentage of additives incorporated into sintered bricks.

[0040] The chemical composition detection method is X-ray fluorescence spectroscopy.

[0041] In step 1), waste clay can be directly used as a mixing raw material for sintered bricks with different requirements. The sintered brick auxiliary materials and waste clay are mixed according to the percentage of sintered brick auxiliary materials added to prepare waste clay sintered bricks.

[0042] This invention, by examining the relationship between the ratio of refractory components to fluxing components (SA / R value) and the required compressive strength of sintered bricks, scientifically and rationally selects the types of auxiliary materials from the perspective of material reaction mechanisms, and calculates appropriate auxiliary material dosages. This fully utilizes the effective components of the raw materials, enabling sintered products to achieve superior strength grades. It solves the problem of adjusting the proportions in the preparation of sintered bricks from waste clay of different sources and compositions.

[0043] The beneficial effects of this invention are:

[0044] 1. The material formulation is highly scientific. This invention scientifically and rationally selects the types of auxiliary materials from the perspective of material reaction mechanism and calculates the appropriate amount of auxiliary materials, which can make full use of the effective components of raw materials and enable sintered products to obtain a better strength grade.

[0045] 2. High feasibility. This invention only requires chemical composition testing of raw materials and excipients, and the dosage of excipients can be obtained through calculation. The operation is simple and convenient.

[0046] 3. Wide applicability. This invention can be used to select and adjust the proportions of sintering additives for waste clay from different regions and sources that meet the basic requirements.

[0047] 4. Good socio-economic benefits. It provides a high-value resource utilization approach for waste clay, with significant social, environmental, and economic benefits. Attached Figure Description

[0048] Figure 1 This is a graph showing the relationship between the SA / R value of sintered brick raw materials and their compressive strength. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Example 1

[0051] In this embodiment, subway tunnel slurry cake from waste clay is selected as the mixing raw material directly without the addition of additives.

[0052] The specific process for preparing sintered bricks for subway tunnel boring machine mud cakes is as follows:

[0053] 1) The chemical composition of the subway tunnel boring machine mud cake was determined by X-ray fluorescence spectroscopy, as shown in Table 1. The mass percentage of its refractory components was calculated. mass percentage of fluxing components ;

[0054] Table 1 Chemical composition of tunnel boring machine mud cake

[0055]

[0056] Mass percentage of refractory components in subway tunnel boring machine mud cake The specific calculation is as follows:

[0057]

[0058] in, Indicates the mass fraction; It is silicon dioxide. It is aluminum oxide;

[0059] Mass percentage of fluxing components in subway tunnel boring machine mud cake The specific calculation is as follows:

[0060]

[0061] in, It is calcium oxide. Ferric oxide It is magnesium oxide. It is potassium oxide. It is sodium oxide.

[0062] The mass percentage of refractory components in subway tunnel lining mud cake and mass percentage of fluxing components The ratio of SA / R, used as the SA / R value of the subway tunnel boring machine mud cake, is calculated according to the following formula:

[0063]

[0064] 2) Construct a fitting formula for the relationship between the SA / R value of the subway shield tunneling mud cake and the compressive strength of sintered bricks, specifically:

[0065]

[0066] Wherein, P represents the compressive strength of the subway shield tunnel mud cake without the addition of sintered brick additives. This indicates the SA / R value of the tunnel boring machine's mud cake.

[0067] like Figure 1 As shown, based on the SA / R value of the subway shield mud cake obtained in step 1), if the SA / R value is > 4.6, then sintered brick auxiliary material with an SA / R value less than 4.6 should be selected. In this embodiment, the auxiliary material selected is steel slag.

[0068] The target of the mixed raw materials after adding sintered brick auxiliary materials was calculated based on the fitting formula. The value is obtained by inverse calculation using the fitting formula:

[0069]

[0070] in, This indicates the actual compressive strength required for the sintered bricks used in subway tunnel boring machines. Indicates the target of the mixed raw materials after adding steel slag. value;

[0071] The required compressive strength of sintered bricks based on actual requirements Given a pressure of 30 MPa, calculate the target pressure of the mixed raw material after adding steel slag. The value is 5.918, which is =5.918;

[0072] 3) After selecting steel slag as the auxiliary material, the chemical composition of the steel slag was determined by X-ray fluorescence spectroscopy (see Table 2), and the mass percentage of its refractory components was calculated. mass percentage of fluxing components ;

[0073] The specific chemical composition of steel slag is as follows:

[0074] Table 2 Chemical composition of steel slag

[0075]

[0076] The calculation of the mass percentage of refractory components in steel slag is as follows:

[0077]

[0078] in, This indicates the mass percentage of refractory components in steel slag;

[0079] The calculation of the mass percentage of fluxing components in steel slag is as follows:

[0080]

[0081] in, This indicates the mass percentage of fluxing components in steel slag.

[0082] 4) According to , , , The target of the mixed raw materials after adding steel slag The percentage of steel slag incorporated is calculated using the following formula;

[0083] Specifically:

[0084] ×1%

[0085] in, This indicates the percentage of steel slag incorporated. Calculated using the above formula, the percentage of steel slag incorporated is 7.3%, which is the percentage of the total mass of the mixed raw materials.

[0086] 5) Mix steel slag and subway shield tunnel mud cake according to the percentage of steel slag added, age them, and then carry out molding, drying and firing operations to prepare subway shield tunnel mud cake sintered bricks.

[0087] Example 2

[0088] In this embodiment, river dredging sludge from waste clay is selected as the mixing raw material directly without the addition of additives;

[0089] The specific process for preparing sintered bricks from river dredging sludge is as follows:

[0090] 1) The chemical composition of the dredged sludge was determined by X-ray fluorescence spectroscopy, as shown in Table 3. The mass percentage of the refractory components was calculated. mass percentage of fluxing components ;

[0091] Table 3 Chemical composition of dredged river sludge

[0092]

[0093] Percentage of refractory components in dredged river silt The specific calculation is as follows:

[0094]

[0095] in, Indicates the mass fraction; It is silicon dioxide. It is aluminum oxide;

[0096] Mass percentage of fluxing components in dredged river silt The specific calculation is as follows:

[0097]

[0098] in, It is calcium oxide. Ferric oxide It is magnesium oxide. It is potassium oxide. It is sodium oxide.

[0099] The mass percentage of refractory components in river dredging sludge and mass percentage of fluxing components The ratio of SA / R of the dredged silt is used as the SA / R value, and is calculated according to the following formula:

[0100]

[0101] 2) Construct a fitting formula for the relationship between the SA / R value of river dredging sludge and the compressive strength of sintered bricks, specifically:

[0102]

[0103] Wherein, P represents the compressive strength of river dredging sludge without the addition of sintered brick additives. The SA / R value represents the dredged silt in the river channel;

[0104] like Figure 1 As shown, based on the SA / R value of the sintered bricks obtained in step 1), if the SA / R value is less than 4.6, then sintered brick auxiliary materials with an SA / R value greater than 4.6 should be selected. In this embodiment, the auxiliary material selected is fly ash.

[0105] The target of the mixed raw materials after adding fly ash was calculated based on the fitting formula. The value is obtained by inverse calculation using the fitting formula:

[0106]

[0107] in, This indicates the compressive strength of the sintered bricks made from the actual required river dredging sludge. Indicates the target of the mixed raw materials after adding fly ash. value;

[0108] Based on actual requirements, the compressive strength needed for sintered bricks made from river dredging sludge is 30 MPa. The target strength of the mixed raw materials after adding fly ash is calculated using a fitting formula. The value is 3.942, which is =3.942;

[0109] 3) After selecting fly ash as the auxiliary material, the chemical composition of the fly ash was determined by X-ray fluorescence spectroscopy (see Table 4), and the mass percentage of its refractory components was calculated. mass percentage of fluxing components ;

[0110] The specific chemical composition of fly ash is as follows:

[0111] Table 4 Chemical composition of fly ash

[0112]

[0113] The calculation of the mass percentage of refractory components in fly ash is as follows:

[0114]

[0115] in, This indicates the mass percentage of refractory components in fly ash;

[0116] The calculation of the mass percentage of fluxing components in fly ash is as follows:

[0117]

[0118] in, This indicates the mass percentage of fluxing components in fly ash;

[0119] 4) According to , , , The target of the mixed raw materials after adding fly ash The percentage of fly ash incorporated was calculated.

[0120] Specifically:

[0121] ×1%

[0122] in, This indicates the percentage of fly ash incorporated. Calculated using the above formula, the percentage of fly ash incorporated is 5.67%.

[0123] 5) Prepare river dredging sintered bricks by mixing fly ash and river dredging sludge according to the percentage of fly ash added.

[0124] The examples described above are merely results of this invention in this instance, but the specific implementation of this invention is not limited to this example. Any alternative solutions with similar effects proposed in accordance with the principles and ideas of this invention should be considered within the scope of protection of this invention.

Claims

1. A method for preparing waste clay sintered bricks based on SA / R value, characterized in that: The method includes the following steps: 1) For sintered bricks, the required additives are added to waste clay to obtain a mixed raw material. The chemical composition of the mixed raw material is analyzed and the mass percentage of refractory components in the mixed raw material is calculated. and mass percentage of fluxing components And based on the mass percentage of refractory components in the mixed raw materials. and mass percentage of fluxing components The SA / R value of the mixed raw materials was calculated; 2) Construct a fitting formula based on the relationship between the SA / R value of the mixed raw materials and the compressive strength of sintered bricks. Then, based on the actual required compressive strength of the sintered bricks, select the sintered brick additives to be added to the mixed raw materials using the SA / R value of the mixed raw materials in the fitting formula. Finally, calculate the target strength of the mixed raw materials after adding the sintered brick additives using the fitting formula. value; 3) Conduct chemical composition analysis on the sintered brick auxiliary materials and calculate the mass percentage of refractory components in the sintered brick auxiliary materials. and mass percentage of fluxing components ; 4) According to the above , , , The target of the mixed raw materials after adding sintered brick auxiliary materials The value is used to calculate the percentage of additives used in sintered bricks; 5) Prepare waste clay sintered bricks by mixing sintered brick auxiliary materials, waste clay and additives according to the percentage of sintered brick auxiliary materials added. In step 1), the mass percentage of the refractory component Calculate using the following formula: in, This indicates the mass percentage of the refractory component in the mixed raw materials; Indicates mass fraction; SiO2 is silicon dioxide, Al2O3 is aluminum oxide; Mass percentage of fluxing components Calculate using the following formula: in, This indicates the mass percentage of fluxing components in the mixed raw materials; CaO is calcium oxide, Fe2O3 is ferric oxide, MgO is magnesium oxide, K2O is potassium oxide, and Na2O is sodium oxide. In step 1), the mass percentage of the refractory component in the mixed raw materials is... and mass percentage of fluxing components The ratio of the two components is used as the SA / R value of the mixed raw materials, and is calculated according to the following formula: Where S represents silicon dioxide in the refractory component, A represents aluminum oxide in the refractory component, and R represents calcium oxide (CaO), ferric oxide (Fe2O3), magnesium oxide (MgO), potassium oxide (K2O), and sodium oxide (Na2O) in the fluxing component. Indicates the mass fraction; In step 2), the fitting formula for the relationship between the SA / R value of the mixed raw materials and the compressive strength of the sintered bricks is as follows: Where P represents the compressive strength of sintered bricks without added sintering brick additives. This indicates the SA / R value of the mixed raw materials; In step 2), the sintered brick auxiliary material selected for addition to the mixed raw materials is specifically as follows: When the SA / R value is less than 4.6, the auxiliary material for sintered bricks should be either fly ash or shale. When the SA / R value is greater than 4.6, the auxiliary material for sintered bricks should be either fly ash or steel slag. In step 2), the target of mixing the raw materials after adding sintered brick auxiliary materials is... The value is obtained by inverse calculation using the following fitting formula, specifically: in, This indicates the actual required compressive strength of the sintered brick. This indicates the target of the mixed raw materials after adding sintered brick additives. value; In step 4), the percentage of sintered brick additives is obtained by processing it as follows: in, This indicates the percentage of additives incorporated into sintered bricks.

2. The method for preparing waste clay sintered bricks based on SA / R value according to claim 1, characterized in that: In step 1), the waste clay is clay waste generated during the basic engineering and river dredging construction. The waste clay includes clay minerals with a mass content of 20-60%, clay particles with a mass content of 15-45% and a particle size of 0-0.002mm.

3. The method for preparing waste clay sintered bricks based on SA / R value according to claim 1, characterized in that: In step 3), after chemical composition analysis of the sintered brick auxiliary materials, the mass percentage of refractory components in the sintered brick auxiliary materials is determined. According to the mass percentage of the refractory component in the mixed raw materials in step 1), Calculated in the same way, the mass percentage of fluxing components in sintered brick auxiliary materials According to the mass percentage of fluxing components in the mixed raw materials in step 1). Calculated in the same way.

Images