A kind of harmless treatment method and treatment device of white mud

Abstract

The invention relates to the field of environmental protection technology, and specifically discloses a harmless treatment method and treatment device for white mud; the water content of the original white mud is reduced to less than 10%; the white mud with a water content of less than 10% is ground; the ground white mud is screened, the separated large particles of white mud are returned to the grinding step for re-grinding, and the small particles are sent to decarbonization treatment; the decarbonized white mud is calcined and then mixed twice in succession to obtain a finished cement product. It also includes drying, grinding equipment, and screening equipment; the screening equipment is provided with a first screen and a second screen and different filter hole diameters; it is also provided with a first outlet and a second outlet, and the first outlet and the second outlet are respectively connected to the decarbonization equipment and / or the grinding equipment; the first mixing and the second mixing of the white mud are respectively carried out by a mixing mechanism and a ball mill; the white mud is converted into cement after harmless treatment, which conforms to the concept of green environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to a harmless treatment method and a treatment device for white mud. Background Art

[0002] With the acceleration of the industrialization process, the emission of various industrial wastes is constantly rising. The waste generated by the papermaking industry - white mud, has become an environmental problem that cannot be ignored. White mud mainly comes from the sludge generated during the treatment of papermaking wastewater. It is rich in inorganic salts, minerals and organic matter. If the accumulation and treatment of white mud are improper, it will cause serious pollution to the environment. Traditional methods of treating white mud, such as direct dumping or landfilling, will not only occupy precious land resources, but also may release harmful gases during the treatment process, causing continuous negative impacts on the environment and ecology. Therefore, how to achieve efficient and environmentally friendly treatment of white mud has become a hot issue in the current field of technical research.

[0003] At present, some white mud processing technologies have been developed, including dehydration, calcination, recycling and other methods. However, these technologies still face many challenges. First, the moisture content of white mud is usually very high, which requires a lot of energy to be consumed in the dehydration and drying process, and the processing time is relatively long, resulting in a large overall energy consumption. Secondly, the existing grinding and screening equipment is often not ideal in terms of processing accuracy, resulting in uneven particle size distribution of white mud, and it is difficult to effectively divert large particles of white mud for secondary treatment, which directly affects the efficiency of subsequent decarbonization and calcination processes. Finally, the decarbonization and calcination processes of white mud usually require different temperature conditions and atmospheres, which requires the use of multiple equipment for segmented processing. This practice not only increases the investment cost of the equipment, but also increases energy consumption.

[0004] The patent "A method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud" (publication number CN118561534A, hereinafter referred to as prior art 1) discloses a method for manufacturing cement using white mud. Prior art 1 is to mix printing and dyeing sludge and papermaking white mud and add ordinary Portland cement to prepare low-carbon cement. This method for preparing low-carbon cement can not only reduce the amount of traditional cement used in the concrete preparation process, but also reduce, recycle and green the solid waste such as printing and dyeing sludge and papermaking white mud, which are difficult to recycle, and also utilize the high alkalinity of papermaking white mud to neutralize the acidic substances in the printing and dyeing sludge, thereby improving the performance of cement. However, this method of manufacturing cement using white mud has more process steps and uses more parts and equipment, which will make the transportation route longer during processing, resulting in the problem of low processing efficiency during processing. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a white mud harmless treatment method and treatment device to solve the problem in the prior art that the process route of the equipment setting is long, resulting in complex equipment, long transportation path and poor treatment efficiency.

[0006] In the first aspect, an embodiment of the present invention provides a method for harmless treatment of white mud, comprising: reducing the moisture content of the original white mud to below 10%; grinding the white mud with a moisture content below 10%; screening the ground white mud, returning the separated large particles of white mud to the grinding step for re-grinding, and sending the small particles to decarbonization treatment; calcining the decarbonized white mud and then performing two mixing operations in succession to obtain a finished cement product.

[0007] Preferably, the method of reducing the moisture content of the original white mud to below 10% comprises: using a drying device to dry the white mud at a temperature of 120°C to 150°C for 10 to 20 minutes; wherein the drying temperature of the white mud is selected based on at least one of the following factors: the evaporation rate of water in the white mud, the organic components in the white mud, the inorganic components in the white mud, and the adaptability of the drying equipment; wherein the drying time of the white mud is selected based on at least one of the following factors: the initial moisture content of the white mud, the initial particle size of the white mud particles, the efficiency of the drying equipment, and the target moisture content of the white mud.

[0008] Preferably, the process of grinding the white mud with a moisture content below 10%; screening the ground white mud, returning the separated large-particle white mud to the grinding step for re-grinding, and sending the small particles to decarbonization treatment includes: grinding the white mud with a moisture content below 10% for 30 to 60 minutes by a grinding device or grinding the white mud with a moisture content below 10% into granules; screening the ground white mud particles by a screening device, and sending the white mud particles with a particle diameter less than 1 mm to the next step for processing; the white mud with a particle diameter greater than 1 mm can be sent back to the screening device for re-grinding until the white mud particles are less than 1 mm and then sent to the next step for processing.

[0009] Preferably, the white mud is decarbonized by a decarbonization device, the decarbonization temperature of the white mud is 400°C to 500°C, and the decarbonization time is 1.4 to 1.8 hours; the white mud is calcined by a calcining furnace, the calcination temperature of the white mud is 850°C to 950°C, and the calcination time is 4 to 8 hours.

[0010] Preferably, the decarbonized white mud is calcined and then mixed twice to obtain a finished cement product, including: the first mixing includes the following components in proportion: white mud accounts for 65-70%, gypsum accounts for 4-6%, slag powder accounts for 12-18%, and fly ash accounts for 8-12%, and a primary mixture is obtained after mixing; the second mixing includes the following components in proportion: the primary mixture accounts for 55-65%, gypsum accounts for 3-5%, slag powder accounts for 12-18%, fly ash accounts for 6-10%, early strength agent accounts for 3-5%, fluidity regulator accounts for 0.5-2%, and mineral activator accounts for 6-10%, and a secondary mixture is obtained after mixing.

[0011] In the second aspect, a harmless treatment device for white mud is provided, comprising a drying device and a grinding device connected to the drying device, wherein the grinding device grinds the white mud into white mud particles; and also comprises a screening device for screening the white mud particles, wherein the screening device is provided with a first screen and a second screen; the first screen and the second screen are provided with different filter hole diameters and are arranged at an inclination; the first screen and the second screen are provided with a first outlet and a second outlet at the bottom, respectively, and the first outlet and the second outlet are connected to the decarbonization device and the grinding device, respectively; the first mixing and the second mixing of the white mud are carried out by a mixing mechanism and a ball mill, respectively; wherein the decarbonization device and the calcination device are operated by the same device.

[0012] Preferably, the drying equipment is provided with a base and a drying body supported by the base; a heating chamber is provided between the outer shell and the inner shell of the drying body, and the inner shell is provided in a through state as the drying chamber; a number of evenly distributed heating pipes are provided in the heating chamber, and a number of heat conducting plates are also provided in the drying chamber; the heat conducting plates are arranged in a spiral shape, and white mud flow channels are provided between adjacent heat conducting plates; the heating pipe transfers heat to the inner shell, the drying chamber and the heat conducting plates in the drying chamber by heat transfer; a rotating part supporting the drying body and a driving part driving the drying body are provided on the base.

[0013] Preferably, the screening equipment includes a frame and a screening part arranged on the frame; the first screen and the second screen are adjacently arranged on the screening part; wherein the first screen is arranged at the higher end of the screening part, and the second screen is arranged at the lower end of the screening part.

[0014] Preferably, the screening part also includes a screening frame arranged on the first screen and the second screen; the screening frame is driven by a motor and slides based on the two ends of the frame, and the screening frame performs a second crushing and squeezing on the fallen white mud particles while sliding, so that the white mud particles pass through the first screen and / or the second screen.

[0015] Preferably, the decarbonization equipment and calcination equipment both use a rotary furnace for decarbonization and calcination operations; the rotary furnace includes a rotating body, and an installation area and an operating chamber are adjacently arranged inside the rotating body; a plurality of guide plates are provided in the operating chamber; a feeding mechanism is also provided on a plurality of the guide plates in the operating chamber; the feeding mechanism includes a sleeve provided on the plurality of the guide plates, and a feeding bin provided inside the sleeve, and a feeding auger rotating based on the two ends of the feed bin is provided in the feed bin; the two ends of the operating chamber are respectively a first feeding end and a first discharging end; the two ends of the feed bin are respectively a second feeding end and a second discharging end, and the feed bin extends from the first discharging end to the first feeding end.

[0016] The harmless treatment method and treatment device of white mud provided by the present invention have the following beneficial effects: In the present application, the equipment structure is simplified and the equipment integration is improved. In the prior art, decarbonization and calcination usually require two independent devices for treatment, which increases the investment and maintenance cost of the equipment. This method integrates the decarbonization and calcination equipment to complete the decarbonization and calcination processes in the same equipment, which simplifies the equipment structure and reduces energy waste. This equipment integration design reduces the number of material transfers and heating times, reduces energy consumption, and improves production efficiency. Through this treatment method, the white mud is converted into cement after harmless treatment, which not only solves the problem of white mud accumulation, but also realizes the resource utilization of white mud. This treatment method is in line with the concept of green environmental protection, helps to reduce environmental pollution, and meets the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following is a brief introduction to the drawings required for use in the embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0018] Figure 1 It is a schematic diagram of a white mud harmless treatment device;

[0019] Figure 2 It is a schematic diagram of the drying equipment structure of a white mud harmless treatment device;

[0020] Figure 3 It is a schematic diagram of the structure of the screening equipment of the white mud harmless treatment device;

[0021] Figure 4 It is a schematic diagram of the rotary kiln structure of a white mud harmless treatment device;

[0022] Parts and numbers in the picture:

[0023] 100-drying equipment, 110-base, 120-drying body, 121-outer shell, 122-inner shell, 123-heating chamber, 124-drying chamber, 125-heat conducting sheet, 126-heating pipeline, 127-white mud flow channel, 130-rotating part, 140-driving part, 151-discharging end, 152-feeding end, 153-leakage hole;

[0024] 200-grinding equipment;

[0025] 300-screening equipment, 310-frame, 320-screening part, 321-first screen, 322-second screen, 323-first outlet, 324-second outlet, 330-screening frame;

[0026] 400-mixing mechanism;

[0027] 500-Ball mill;

[0028] 600-rotary furnace, 610-rotating body, 611-heating assembly, 612-operating chamber, 613-first feeding end, 614-first discharging end, 615-guide plate, 620-feeding mechanism, 621-sleeve, 622-feeding bin, 623-second feeding end, 624-second discharging end, 625-feeding auger;

[0029] 700-hoist. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described in conjunction with the drawings in the embodiment of the present invention. It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device. In the absence of further restrictions, the elements defined by the phrase "comprising..." do not exclude the existence of other identical elements in the process, method, article or device comprising the elements. If there is no conflict, the embodiments of the present invention and the various features in the embodiments can be combined with each other, all within the protection scope of the present invention.

[0031] Example 1

[0032] The embodiment of the present invention provides a method for harmless treatment of white mud, comprising:

[0033] The moisture content of the original white mud is reduced to below 10%. Furthermore, the dried white mud can be continuously dried to reduce its moisture content to less than 5%.

[0034] The initial moisture content of white mud is usually high. If grinding and decarbonization are carried out directly, the humidity will increase the burden on the processing equipment, resulting in reduced efficiency and increased energy consumption. By reducing the moisture content to 10% or even below 5% through drying, the heat required in the subsequent process can be reduced, and the overall energy consumption can be reduced. In addition, white mud with high humidity and high water content is easy to adhere to the inner shell 122 or the grinding disc of the grinding equipment 200, affecting the uniformity and efficiency of grinding. By controlling the moisture content below 10%, the fluidity of the white mud particles is better, and they can be evenly processed to the required particle size during the grinding process to prevent clogging during the screening process. If the moisture content of the white mud is too high, the particles may stick together during screening, resulting in clogging of the sorting equipment and reduced sorting accuracy. Reducing the moisture content to 10% or even below 5% can ensure that the particles remain dispersed during the screening process, reduce equipment failures, and improve subsequent decarbonization and calcination effects.

[0035] Furthermore, when decarbonizing and calcining white mud with high moisture content, a large amount of heat is first consumed to evaporate the water, which not only reduces the utilization rate of thermal energy, but also may cause fluctuations in the processing temperature, thereby affecting the effect of carbonate decomposition. Controlling the moisture content below 10% or even 5% can reduce this part of the heat demand and ensure the stability and efficiency of decarbonization and calcination.

[0036] See also Figure 1 , using drying equipment 100, the white mud is dried at a temperature of 120°C to 150°C for 10 minutes to 20 minutes. The selection of the drying temperature needs to be set according to factors such as the water evaporation rate of the white mud. The white mud has a high water content, most of which is free water and bound water, and sufficient heat is required to evaporate the water during the drying process. By setting the drying temperature range to 120°C to 150°C, the evaporation of water can be effectively accelerated to achieve the expected moisture content requirements. In addition to water, the white mud also contains a certain amount of organic matter. These organic substances may undergo pyrolysis reactions at high temperatures. Setting the drying temperature between 120°C and 150°C can effectively remove most of the water in the white mud without over-decomposing the organic matter or causing unnecessary side reactions. And the inorganic components of the white mud (such as aluminum, silicon, calcium, etc.) need to remain stable during the treatment process. At a drying temperature of 120°C to 150°C, the inorganic components in the white mud will not undergo significant thermal reactions, and can maintain its structural stability, preparing for subsequent decarbonization and calcination steps.

[0037] The drying temperature of the white mud is selected according to at least one of the following factors:

[0038] The evaporation rate of white mud. White mud with high moisture content requires higher temperature to accelerate the evaporation of moisture. For example, for white mud with higher moisture content (such as above 70%), a higher temperature range (such as 150°C) can be selected to quickly remove moisture. For white mud with lower moisture content, the evaporation rate of moisture will be relatively slow, so choosing a lower temperature (such as 120°C) can remove water more gently and avoid composition changes caused by over-drying.

[0039] Organic components in white mud (such as organic pollutants, plant residues, etc.) are easily decomposed at high temperatures. If there are more organic components in the white mud, choosing a lower drying temperature (such as 120°C) can reduce gas emissions and energy waste during the decomposition of organic matter. If there are fewer organic components in the white mud, the drying temperature can be appropriately increased (such as 150°C) to improve the drying efficiency.

[0040] The inorganic components in white mud are usually relatively stable to temperature. Choosing too high a temperature may cause thermal decomposition or changes in certain minerals, affecting the results of subsequent steps. For white mud with more inorganic components, a milder drying temperature (such as 120°C) is usually selected. If the inorganic components are less and less likely to react, increasing the temperature appropriately can improve the drying efficiency.

[0041] The adaptability of the drying device 100. Different drying devices 100 (such as spiral drying devices, hot air furnaces, fluidized bed dryers, etc.) have different operating temperature ranges and efficiencies. For example, the temperature of a fluidized bed dryer usually needs to be controlled in a higher range, while a hot air furnace may be suitable for long-term drying at a lower temperature. When selecting the temperature, the adaptability of the equipment should be considered to ensure that the equipment operates in the optimal efficiency range and does not overload.

[0042] The drying time of the white mud is selected according to at least one of the following factors:

[0043] The initial moisture content of white mud. When the initial moisture content of white mud is high, a longer drying time is required to remove excess water. For example, white mud with an initial moisture content of more than 70% may require a longer drying time (such as 20 minutes) to reach the target moisture content. When the initial moisture content is low, the drying time can be shortened accordingly to improve production efficiency.

[0044] The initial particle size of white mud particles. Larger white mud particles require longer drying time because large particles will cause slower evaporation of water and lower heat conduction efficiency of the entire material. Smaller white mud particles (cemented tiny particles, etc.) can be heated faster and more evenly, so the drying time can be shorter.

[0045] The efficiency of the drying device 100. An efficient drying device 100 can remove more water in a shorter time. Therefore, for a drying device 100 with a higher efficiency, the drying time can be appropriately reduced. For a device with a lower efficiency, it may take longer to reach the target moisture content.

[0046] The target moisture content of white mud, if the target moisture content is low (such as below 10%), requires a longer drying time to ensure that the water evaporates completely. If the target moisture content is high, the drying time can be appropriately shortened.

[0047] Grind the white mud with a moisture content below 10%.

[0048] The ground white mud is screened, the separated large particles are returned to the grinding step for re-grinding, and the small particles are sent to decarbonization treatment.

[0049] By using the grinding device 200, the white mud with a moisture content controlled below 10% is finely ground for a duration of about 30 to 60 minutes. The purpose of this process is to grind the white mud into fine particles for subsequent processing and application; after the grinding is completed, the ground white mud particles are screened using the screening device 300. During the screening process, the white mud particles with a particle diameter of less than 1m will be screened through the screening device 300 to the next step for processing; for those white mud particles with a particle diameter greater than 1mm, they will be sent back to the screening device 300 for further grinding. This process will continue to ensure that the white mud particles entering the subsequent process meet the required particle size standards.

[0050] The decarbonized white mud is calcined and mixed twice to obtain a cement product. The white mud is decarbonized by a decarbonization device, the decarbonization temperature of the white mud is 400° C. to 500° C., and the decarbonization time is 1.4 to 1.8 hours.

[0051] In the present embodiment, the white mud (secondary mixed material) after two mixings is processed by a specific decarbonization device to remove the carbon component therein. In the decarbonization process, the white mud after two mixings is decarbonized in a device provided with a preheating temperature. After the white mud is added to the device, the device is gradually heated to a specific temperature range, i.e., 400°C to 500°C, to ensure that the decarbonization reaction is effectively carried out. This temperature can not only ensure the decarbonization efficiency, but also will not cause unnecessary damage to other components of the white mud. After reaching the set decarbonization temperature, the white mud will be kept at this temperature for a period of time, and this time length is set to 1.4 to 1.8 hours. The setting of this period of time is based on actual operating experience and calculations, and is intended to ensure that the decarbonization process can be fully carried out, thereby achieving the desired decarbonization effect. Through such treatment, the carbon content in the white mud will be significantly reduced, making it more suitable for subsequent use or processing steps.

[0052] The decarbonization process of white mud is mainly to remove the carbonate and organic components it contains. The decomposition temperature of these components determines the temperature that may need to be reached during the decarbonization of white mud; for example, calcium carbonate (Cac0) begins to decompose at about 400°C, releasing carbon dioxide to form calcium oxide (Ca0). Most organic matter in white mud begins to decompose at 350°C-450°C, and a higher temperature is required for complete decomposition. It is also necessary to ensure the thermal stability of inorganic impurities, such as certain silicates and aluminates remain stable at high temperatures to avoid the destruction of mineral structures caused by higher temperatures; therefore, it is necessary to adjust the decarbonization temperature range according to the different carbon content of the substances contained in the white mud.

[0053] Therefore, the temperature of 400℃ to 500℃ is selected to ensure the sufficiency of the decarbonization reaction; the white mud begins to decompose calcium carbonate at 400℃, and the decomposition is completed and impurities are removed at 500℃, reducing the initial carbon content in the white mud to the expected carbon content. The reasonable setting of the decarbonization temperature can also avoid the waste of too high temperature. For example, when the decarbonization temperature exceeds 600℃, the energy consumption of the decarbonization equipment will be significantly increased, and it may also cause unnecessary reactions of substances, such as changes in mineral phases.

[0054] Furthermore, there is a connection between the decarbonization time of white mud and the reaction rate. When the temperature of white mud decarbonization is selected in the temperature range of 400℃ to 500℃, the decomposition rate of carbonate is proportional to the temperature. Practice shows that when the decarbonization temperature of white mud is around 400℃, it takes about 1.7 hours to completely decarbonize; at 500℃, the decomposition can be completed in 1.4 hours.

[0055] And according to the time, when the decarburization time is less than 1.4 hours, the energy consumption will increase significantly and the processing efficiency will be reduced. When the decarburization time exceeds 2 hours, the temperature is low and the decarburization will be insufficient. Choosing 1.4 to 1.8 hours can achieve a balance between decarburization completeness and energy consumption.

[0056] Comparison of decarburization time and temperature effect:

[0057]

[0058] In the calcination of the white mud, the white mud is calcined in a calcining furnace, the calcination temperature of the white mud is 850° C. to 950° C., and the calcination time is 4 to 8 hours.

[0059] Calcination is a key step in processing white mud into cement, which involves the activation of mineral components in white mud and the formation of new phase structures. Specifically, white mud contains a certain amount of silicates, aluminates and calcium oxide. In the temperature range of 850℃ to 950℃, these minerals can be fully activated and react with other mixing ingredients to form calcium silicate and calcium aluminate phases with good hydration properties.

[0060] In actual calcination, when the temperature exceeds 950℃, the white mud particles may be over-sintered or melted, resulting in particle agglomeration, which is not conducive to subsequent grinding and mixing operations and increases energy consumption. When the temperature is below 850℃, the transformation of many mineral phases is not completed, resulting in insufficient activity of the white mud and low strength of the generated cement.

[0061] Furthermore, the calcination time of white mud determines the uniform heating degree of white mud and the sufficiency of mineral reaction. If the calcination time of white mud is shorter than 4 hours, the central particles of white mud may not fully reach the reaction temperature, resulting in insufficient mineral phase formation; if it exceeds 8 hours, the reaction tends to be saturated, and further extension of the time is difficult to significantly improve the effect, but increases energy consumption.

[0062] The calcination process of white mud requires sufficient diffusion of heat to ensure uniform reaction inside and on the surface of the particles, especially in the range of 850°C to 950°C, which requires sufficient time to complete the reaction.

[0063] In this embodiment, the calcination temperature of 850°C to 950°C is selected to ensure that the key mineral phases such as silicates and aluminates in the white mud are fully reacted, the activity is the highest, and the prepared cement has better performance. Compared with higher temperatures, maintaining calcination in the range of 850°C to 950°C can achieve the ideal conversion effect with lower energy consumption. The matching of calcination time and temperature avoids particle melting and agglomeration, ensuring the efficiency and quality of subsequent grinding and mixing.

[0064] Practical data show that the cement hydration performance of white mud processed at 850℃ to 950℃ within 4 to 8 hours is the best, while short-term or low-temperature calcination results in more unreacted phases, making the cement hydration strength relatively low. The calcium silicate phase and calcium aluminate phase generated under the conditions of this scheme have higher contents, which significantly improves the cement strength.

[0065] The reasonable combination of temperature and time avoids over-sintering of mineral components and ensures that cement has stable early and late hydration rates. Appropriate calcination conditions maintain the particle size and mineral uniformity of white mud, which is beneficial to the overall consistency of the mixing and cement performance.

[0066] Comparison of calcination time and temperature effects:

[0067]

[0068] The method of calcining the decarbonized white mud and then performing two mixing operations successively to obtain a cement product comprises:

[0069] Through the first mixing, white mud is preliminarily mixed with gypsum, slag powder and fly ash to ensure the uniform distribution of basic components for subsequent processing. The introduction of slag powder and fly ash can improve the compressive strength and durability of cement, while gypsum is used to adjust the setting time and ensure the stability of the initial and final setting properties of cement.

[0070] The first mix includes the following proportions:

[0071] White mud accounts for 65-75%: White mud is the main raw material and occupies a dominant position. Its proportion ensures the matrix component of the final cement. 65%-75% can adjust the basic performance and production cost according to actual needs, preferably 70%. Gypsum accounts for 5%: Gypsum is used to adjust the setting time of cement. 4-6% is a reasonable range, which can balance the initial setting and final setting time, preferably 5%. Too much may cause the initial setting time of cement to be too long, affecting construction efficiency. Slag powder accounts for 12-18%: Slag powder can improve the compressive strength and durability of cement, while reducing production costs. 15% is a cost-effective ratio that can meet the needs of different strengths. Fly ash accounts for 8-12%: Fly ash is a good filling material that can improve the fluidity of cement and increase the later strength. This ratio can take into account both performance and economy, preferably 8%. The remaining materials are cement auxiliary materials (limestone, clay, etc.). After the first mixing, a primary mixture is obtained.

[0072] Adding early strength agent, fluidity regulator and mineral activator to the second mixing can further improve the performance of cement. Specifically, early strength agent improves early strength, mineral activator enhances the activity of white mud and other components, and fluidity regulator improves the operating performance of cement during construction. The proportion of ingredients in the second mixing is more precise, and the formula can be fine-tuned according to the target performance requirements to ensure that the final cement product meets the design requirements.

[0073] The second mixing includes the following proportions:

[0074] The proportion of primary mixing materials is 55-65%; after the first mixing, white mud is preliminarily mixed with slag powder, fly ash, etc., with high uniformity. During the second mixing, this basic uniformity helps to better mix with newly added functional additives (such as early strength agent, fluidity regulator, mineral activator, etc.), avoiding the problem of uneven distribution of components caused by direct mixing. The proportion of white mud in the second mixing is relatively reduced, which can free up the proportion space and add functional additives (such as early strength agent, mineral activator) to further optimize the performance of the final cement (such as early strength, fluidity, and later strength). The proportion of gypsum is 3-5%: the reduction ratio is based on the fact that the gypsum content in the first mixing is sufficient, and only minor adjustments are made in the second mixing. The proportion of slag powder is 12-18%: the proportion of slag powder remains unchanged to maintain basic strength and durability. The proportion of fly ash is 8%: it is slightly reduced to balance the introduction of other additives to avoid excessive fly ash affecting early strength. The proportion of early strength agent is 3-5%: it enhances early strength and facilitates the acceleration of construction progress. The fluidity regulator accounts for 0.5-2%: improves the fluidity of cement slurry and enhances construction performance. The mineral activator accounts for 6-10%: enhances the activity of white mud, improves the overall strength and reaction rate; after the second mixing is completed, the secondary mixture is obtained.

[0075] Furthermore, the first mixing is a pretreatment of the basic components, laying the foundation for uniformity in subsequent steps, while the second mixing introduces functional additives to achieve more detailed performance optimization. If all components are evenly distributed in one mixing, uneven dispersion may occur due to differences in physical properties between the components (such as density, particle size, and fluidity). Mixing in two batches makes it easier to achieve uniformity. The first mixing evenly mixes the basic components, which helps to enhance their chemical stability, while the second mixing further stimulates mineral activity through the action of additives, making the final performance better.

[0076] Example 2

[0077] See also Figure 1 The embodiment of the present invention provides a white mud harmless treatment device, which is applied to the method described in Example 1.

[0078] The harmless treatment device of white mud provided in this embodiment includes a drying device 100 and a grinding device 200 connected to the drying device 100, and the grinding device 200 grinds the white mud into white mud particles. In this embodiment, the function of the drying device 100 is to process the raw material white mud to a predetermined moisture content for subsequent processing.

[0079] See also Figure 2In this embodiment, the drying device 100 includes a base 110, and a drying body 120 supported and arranged by the base 110. A heating chamber 123 is arranged between the outer shell 121 and the inner shell 122 of the drying body 120, and the heating chamber 123 is arranged as a sealed structure. The outer shell 121 and the inner shell 122 are both arranged in an internally through shape. The outer shell 121 has a heat-insulating effect, which can effectively prevent heat from diffusing outward, thereby maintaining the thermal efficiency inside the equipment. The through part of the inner shell 122 constitutes a drying chamber 124, and the white mud flows in this drying chamber 124. During the flow process, the white mud will absorb the heat from the inner shell 122, thereby completing the drying operation.

[0080] Furthermore, a number of evenly distributed heating pipes 126 are provided in the heating chamber 123. The function of these heating pipes 126 is to effectively transfer heat to the inner shell 122 and the drying chamber 124 by means of heat transfer. In addition, a number of heat-conducting sheets 125 are provided in the drying chamber 124. These heat-conducting sheets 125 are arranged in a spiral shape to increase the contact area with the white mud, thereby improving the heat exchange efficiency; they can also assist the white mud to flow in the drying chamber 124 and improve its drying efficiency. Between adjacent heat-conducting sheets 125, there are white mud flow channels 127 between the spiral heat-conducting sheets 125 to ensure that the white mud can flow smoothly and fully contact the heat-conducting sheets 125 to absorb heat. Through such a setting, it can be ensured that the white mud can absorb heat evenly and efficiently during the drying process.

[0081] In the structure of the base 110, a rotating part 130 and a driving part 140 are provided for supporting and driving the drying body 120. These parts work together to ensure that the drying body 120 can rotate smoothly and efficiently.

[0082] See also Figure 2 Specifically, the rotating part 130 is composed of at least two followers, which are fixedly mounted at appropriate positions of the drying body 120. At the same time, at least two pairs of bearing seats are provided on the base 110, and each pair of bearing seats is in sliding contact with the corresponding followers. This design enables the drying body 120 to rotate smoothly through the sliding contact between the followers and the bearing seats, thereby realizing its drying function.

[0083] In addition, the driving part 140 includes at least one driven gear, which is installed at an appropriate position of the drying body 120. The driving mechanism is composed of a driving motor, a reducer and a driving gear. The driving motor is connected to the reducer through a transmission connection, the reducer is connected to the driving gear, and the driving gear is connected to the driven gear in a transmission connection. By starting the driving motor, the entire driving mechanism works together to drive the drying body 120 to rotate continuously and stably. This driving method not only ensures the rotation speed and efficiency of the drying body 120, but also ensures the reliability and durability of the entire system.

[0084] See also Figure 2 Furthermore, the two ends of the inner shell 122 are respectively set as a discharge end 151 and a feed end 152, so as to facilitate the continuous processing of the material. At the discharge end 151 of the inner shell 122, a plurality of leakage holes 153 are specially set, and the function of these leakage holes 153 is to smoothly transport the preliminarily processed white mud to the next production process. At the same time, these leakage holes 153 also have the function of refining the white mud for the first time, ensuring that the white mud reaches the required particle size requirements before entering the next process. Through this setting, the efficiency of the entire production process and the product quality can be effectively improved.

[0085] See also Figure 1 , the grinding device 200 is directly connected to the outlet of the drying device 100. After the white mud is dried by the drying device 100, the white mud will be discharged from the drying device 100. During the discharge process, the white mud will collide, squeeze and rub with the leakage hole, and these physical forces will perform a preliminary refinement on the white mud. Subsequently, the preliminary refined white mud will enter the grinding device 200 for further grinding. The working efficiency of the grinding device 200 can be effectively improved through the action between the white mud particles and the leakage hole, because the dried and preliminary refined white mud is more easily ground to the particle size that meets the standard push. In this way, not only the time required for the grinding operation is shortened, but also the particle size of the white mud particles is ensured to meet the expected quality requirements, thereby improving the efficiency and product quality of the entire production process.

[0086] See also Figure 1In this embodiment, a white mud harmless treatment device also includes a screening device 300 for screening white mud particles. After grinding, most of the white mud particles have reached the particle size standard for mixed use; however, there may still be some white mud particles whose particle size has not yet reached the expected specification requirements. In this case, it is necessary to use the screening device 300 to carefully classify these white mud particles. Through screening, those white mud particles whose particle size meets the standard we set can smoothly enter the next production process, while those white mud particles whose particle size does not meet the standard need to be sent back to the grinding device 200 for further refinement, generally transported back by the cooperation of the elevator 700 and the conveying component. It is worth noting that after each grinding, all white mud particles need to be screened again to ensure that their particle size fully meets the quality requirements. For those white mud particles that fail to meet the standard during the screening process, they will undergo a repeated grinding process until their particle size meets the expected quality standards.

[0087] See also Figure 3 , the screening device 300 is equipped with two screens, namely the first screen 321 and the second screen 322, and the screens are arranged at an angle. The two screens are arranged to have different filter hole diameters to meet different screening requirements. Specifically, the filter hole diameter of the first screen 321 is set according to the size of qualified white mud particles to ensure that only white mud particles that meet the standards can pass through. The filter hole diameter of the second screen 322 is relatively large, allowing those unqualified or large-sized white mud particles to pass through. During the screening process, the white mud particles will first contact the first screen 321. After screening, those white mud particles that meet the standards will pass through the first screen 321 smoothly and be discharged. At the same time, those unqualified white mud particles will roll onto the second screen 322 because they cannot pass through the filter holes of the first screen 321. Subsequently, these unqualified white mud particles will be discharged through the second screen 322 and guided to the grinding device 200 for further grinding.

[0088] The first screen 321 and the second screen 322 are installed and fixed by the frame 310 of the screening device 300; at the same time, a screening frame 330 is arranged above the first screen 321 and the second screen 322. The screening frame 330 can slide forward and backward through the sliding mechanism on the frame 310 to adapt to different material processing requirements. A number of guide plates are also arranged on the screening frame 330, which are evenly distributed at a certain interval, and each guide plate is arranged in an inclined state to facilitate the smooth flow of materials. In order to realize the movement of the screening frame 330, motors are also arranged outside, which can drive the screening frame 330 to perform linear reciprocating motion according to a predetermined motion trajectory. The screening frame 330 performs a third crushing and extrusion on the fallen white mud particles when performing linear reciprocating motion.

[0089] In actual use, it is first necessary to start the motor set outside, and the motor will make the screening frame 330 perform regular linear reciprocating motion on the frame 310. After the white mud particles are processed by the grinding device 200, they will fall into the designated area of ​​the first screen 321. Under the screening effect of the first screen 321, qualified white mud particles will fall into the next process through the sieve holes on the screen, while those unqualified white mud particles will slide down along the screen surface to the area of ​​the second screen 322 due to the inclination angle of the screen. In this process, the inclined guide plate on the screening frame 330 will continuously scrape the white mud particles accumulated on the screen to ensure that these particles can be discharged smoothly through the screen, avoiding the continuous accumulation of particles on the screen, thereby ensuring the high efficiency and continuity of the screening process.

[0090] See also Figure 1 Furthermore, a first outlet 323 is configured at the bottom of the first screen 321, and a second outlet 324 is configured at the bottom of the second screen 322. The two outlets are respectively connected to the decarbonization equipment and the grinding equipment 200. Specifically, the decarbonization equipment is responsible for receiving qualified white mud particles from the first outlet 323, which have passed the size and quality standards in the screening process. The grinding equipment 200 receives unqualified white mud particles from the second outlet 324, which fail to meet the quality requirements in the screening process and require further grinding to reach the required specifications. Through such a configuration, the white mud particles can be effectively classified and processed to ensure that only particles that meet the standards are sent to the decarbonization equipment, while those that do not meet the standards are sent to the grinding equipment 200 for reprocessing, thereby improving the overall production efficiency and product quality.

[0091] In the process of treating the white mud, the first mixing and the second mixing are respectively performed by the mixing mechanism 400 and the ball mill 500; specifically, the main purpose of the first mixing is to preliminarily mix the white mud with various auxiliary materials to ensure that they can be evenly combined; and the second mixing is a crucial step, which not only involves the mixing of the white mud with various ingredients, but also includes the careful grinding and fusion of these ingredients and the white mud to ensure that the final cement has good quality and performance. In the process of making white mud into cement, a pneumatic cement conveyor and / or a belt conveyor is used to transport the raw materials in the production process.

[0092] In the process of white mud processing, in order to improve the convenience of operation, reduce the number of equipment, and simplify the entire operation process, the decarbonization equipment and calcination equipment are operated on the same equipment, which can not only reduce the purchase cost of the equipment, but also reduce the complexity of maintenance and operation. By operating on the same equipment, efficient utilization of resources and significant improvement of operating efficiency can be achieved. Furthermore, the combined use of equipment can also help reduce the floor space, making the entire production environment neater and more orderly.

[0093] See also Figure 4 , the decarburization equipment and calcination equipment both use a rotary kiln 600 to perform the decarburization and calcination operations. Specifically, the rotary kiln 600 includes a rotating body 610, which is provided with at least two parts, namely, an operating chamber 612 and an installation area provided outside the operating chamber 612; wherein the installation area is specifically used to set a heating component 611 (such as a heating tube), and the operating chamber 612 is used to accommodate the secondary mixture that needs to be decarburized or calcined, and to perform decarburization or calcination operations therein. Inside the operating chamber 612, a number of guide blades 615 are provided. When in use, when the heating component 611 in the installation area starts to work and generates heat, the heat will be transferred to the inside of the operating chamber 612, so that the particles of the secondary mixture on the guide blade 615 and in the operating chamber 612 are filled with a large amount of heat. In actual use, the secondary mixture particles will enter the working chamber 612 to prepare for decarburization. First, the secondary mixture particles can receive heat from the heating component 611, so that their temperature gradually rises. At the same time, the secondary mixture particles will move with the rotation of the guide blades 615. The existence of the guide blades 615 not only increases the heating area of ​​the secondary mixture particles, but also effectively prevents the secondary mixture particles from being too thick, ensuring that each part of the secondary mixture particles is heated more evenly during the decarburization process, thereby significantly improving the efficiency and quality of the decarburization operation.

[0094] See also Figure 4In order to further improve the convenience of loading the secondary mixture particles during the decarbonization and calcination process, the present invention sets a feeding mechanism 620 on multiple guide plates 615 in the working chamber 612. These guide plates 615 are not only responsible for the transportation of materials, but also provide necessary support and installation platforms for the feeding mechanism 620. The feeding mechanism 620 includes sleeves 621, which are connected to the guide plates 615 by a rotating connection. Such an arrangement ensures that when the drying body 120 is rotating, the feeding structure can remain stable and will not rotate therewith, thereby realizing a continuous feeding process. At the same time, the presence of the sleeve 621 also effectively isolates the internal components that transport the secondary mixture particles, ensuring the smooth operation of the entire system.

[0095] See also Figure 4 Inside the sleeve 621, a feed bin 622 is provided, and a feed auger 625 capable of rotating based on both ends is installed inside the feed bin 622. During the feeding process, the secondary mixture is first conveyed to the feed auger 625, and then the secondary mixture particles are effectively delivered to the feeding end of the working chamber 612 by driving the rotation of the feed auger 625. The two ends of the working chamber 612 are respectively defined as the first feeding end 613 and the first discharging end 614. The two ends of the feed bin 622 are respectively defined as the second feeding end 623 and the second discharging end 624. It is worth noting that the design of the feed bin 622 is extended, and it extends from the first discharging end 614 to the first feeding end 613. Such a design not only optimizes the flow path of the secondary mixture, but also ensures the smoothness and efficiency of the feeding process, thereby improving the performance of the entire system and the convenience of operation as a whole.

[0096] In this embodiment, the mixing mechanism 400 and the ball mill 500 are both products in the prior art, so they are not described in detail here.

[0097] Example 3

[0098] See also Figure 1 , an embodiment of the present invention provides a calculation formula for the decarbonization time in a harmless treatment method for white mud; in practice, a higher carbon content will inhibit the hydration reaction of cement and reduce the speed of strength development. Undecomposed carbonates may also lead to an increase in pores in the structure, thereby weakening the strength. In addition, excessive carbonate residues in cement may affect the setting time of cement, resulting in uneven solidification during construction. Cement with a low carbon content has higher sulfate resistance and freeze-thaw resistance, and is suitable for more severe environments. Controlling the carbon content also helps to reduce carbon dioxide emissions during processing, which is in line with the development trend of green building materials.

[0099] The calculation formula for decarburization time is as follows:

[0100]

[0101] Where, T is the decarburization time;

[0102] k is the decomposition rate coefficient, and its unit is kg / h·℃; the decomposition rate coefficient k represents the mass of carbon content that can be decomposed per unit time per degree Celsius of decomposition temperature at a specific temperature. The larger the k, the more carbon content in the white mud is decomposed at the same temperature and time, and the faster the reaction rate. The size of k depends not only on the temperature, but also on the properties of the reaction system, the surface area of ​​the white mud particles, the decomposition environment (such as pressure and atmosphere), etc. It comprehensively combines the rate parameters of reaction temperature, time and reaction efficiency to quantify the decomposition acceleration effect when the temperature rises and the reaction efficiency per unit time, reflecting the dynamic changes of the actual decarbonization process. In this embodiment, k is taken as 0.05kg / h·℃.

[0103] M is the mass of the decarbonized white mud in a single time, in kg; in this embodiment, the maximum single processing capacity of the rotary kiln is 500 kg.

[0104] C0 is the initial carbon content of the white mud; the carbon content of ordinary white mud is generally 8% to 15% (mass percentage); it is mainly composed of a high content of calcium carbonate, and the calcium carbonate content usually accounts for 60% to 80% of the total mass of the white mud. The carbon content of industrial waste white mud (such as papermaking white mud) is wider, and may be between 5% and 20%; its carbon content depends on the carbonate content and the organic matter and impurities mixed in, and may contain a small amount of organic carbon. In this embodiment, the carbon content of the white mud is about 7%.

[0105] C target The target carbon content of white mud is 5%. In the raw material processing stage, the carbon content should be controlled below 0.5% by decarbonization and other processes. If it is difficult to completely decarbonize, high-activity mineral materials (such as slag or fly ash) can be added to improve the cement performance and dilute the carbon content. In this embodiment, the target carbon content is 5%.

[0106] T d The decarbonization temperature is 825°C in theory. However, since white mud is a mixture and contains impurities (such as water, silicates, and clay minerals), its actual decarbonization starting temperature will be greatly reduced to about 300°C. Impurities in white mud (such as silicates) will change the thermodynamic and kinetic conditions of the decarbonization reaction and lower the decomposition temperature. The large surface area of ​​tiny particles will also accelerate the reaction and further reduce the required temperature. Within a specific temperature range, the carbonates in white mud can be decomposed by reducing carbon monoxide, so decarbonization can be achieved at 300°C-700°C.

[0107] Through the above decarburization time calculation formula and value, combined with different decarburization temperature ranges, the processing time is calculated respectively:

[0108] When the decarburization temperature is 300℃:

[0109]

[0110] When the decarburization temperature is 400℃:

[0111]

[0112] When the decarburization temperature is 500℃:

[0113]

[0114] When the decarburization temperature is 600℃:

[0115]

[0116] When the decarburization temperature is 700℃:

[0117]

[0118] According to the time, at about 300°C, the temperature is too low. Although the energy consumption is low, the decomposition rate is slow, the efficiency is low, and the reaction is incomplete, which may lead to a high residual carbonate content and affect the quality of cement.

[0119] At 400-500℃, the temperature is moderate, the decomposition rate of calcium carbonate is significantly improved, and undecomposed residues can be effectively avoided. The energy consumption is relatively low and the efficiency is high.

[0120] The decomposition speed is faster at 600-700℃, but the temperature is too high, the energy consumption surges, and it is not economical; at the same time, it may cause unnecessary impurity phase changes (such as silicate phase decomposition or sintering), affecting the subsequent cement performance. And in the range of 400-500℃, other components in white mud (such as silicates and clay minerals) are relatively stable, which can not only complete decarbonization, but also will not generate by-products that are not conducive to the properties of cement due to impurity decomposition. The carbon dioxide emission rate can also be controlled. When the temperature is too low, the carbon dioxide release rate is insufficient, which may lead to a high carbon dioxide concentration in the reaction environment and inhibit the decomposition reaction. At a temperature of 400-500℃, the carbon dioxide release rate is moderate, which is conducive to decomposition.

[0121] And in industrial production, conventional heat-resistant materials can be used in the temperature range of 400-500℃, while 600-700℃ equipment has higher requirements for high-temperature resistant materials, which increases costs.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for harmless treatment of white mud, characterized in that: include: Reduce the moisture content of the original white mud to below 10%; Grinding white mud with a moisture content of less than 10%; The ground white mud is screened, the separated large particles are returned to the grinding step for re-grinding, and the small particles are sent to the decarbonization process; The decarbonized white mud is calcined and then mixed twice to obtain the finished cement product.

2. A harmless treatment method for white mud according to claim 1, characterized in that: The step of reducing the moisture content of the original white mud to below 10% comprises: Using a drying device (100), drying the white mud at a temperature of 120° C. to 150° C. for 10 to 20 minutes; The drying temperature of the white mud is selected according to at least one of the following factors: The evaporation rate of water in the white mud, the organic components in the white mud, the inorganic components in the white mud, and the adaptability of the drying equipment (100); The drying time of the white mud is selected according to at least one of the following factors: The initial moisture content of the white mud, the initial particle size of the white mud particles, the efficiency of the drying device (100), and the target moisture content of the white mud.

3. A harmless treatment method for white mud according to claim 1, characterized in that: The white mud with a moisture content of less than 10% is ground; The ground white mud is screened, the separated large particles are returned to the grinding step for re-grinding, and the small particles are sent to the decarbonization process, including: Grinding the white mud with a moisture content of less than 10% for 30 to 60 minutes or grinding the white mud with a moisture content of less than 10% into granules by means of a grinding device (200); The ground white mud particles are screened by a screening device (300), and the white mud particles with a particle diameter less than 1 mm are sent to the next step for processing; the white mud particles with a particle diameter greater than 1 mm can be sent back to the screening device (300) for re-grinding until the white mud particles are less than 1 mm and then sent to the next step for processing.

4. A harmless treatment method for white mud according to claim 1, characterized in that: include: The white mud is decarbonized by a decarbonization device, the decarbonization temperature of the white mud is 400° C. to 500° C., and the decarbonization time is 1.4 to 1.8 hours; The white mud is calcined in a calcining furnace, the calcination temperature of the white mud is 850° C. to 950° C., and the calcination time is 4 to 8 hours.

5. The harmless treatment method of white mud according to claim 1, characterized in that: The method of calcining the decarbonized white mud and then performing two mixing operations successively to obtain a cement product comprises: The first mixing includes the following proportions: white mud accounts for 65-70%, gypsum accounts for 4-6%, slag powder accounts for 12-18%, and fly ash accounts for 8-12%. After mixing, a primary mixed material is obtained; The second mixing includes the following proportions: the first-level mixture accounts for 55-65%, the gypsum accounts for 3-5%, the slag powder accounts for 12-18%, the fly ash accounts for 6-10%, the early strength agent accounts for 3-5%, the fluidity regulator accounts for 0.5-2%, and the mineral activator accounts for 6-10%. After mixing, the secondary mixture is obtained.

6. A harmless treatment device for white mud, applied to the method according to any one of claims 1 to 5; characterized in that: It comprises a drying device (100) and a grinding device (200) connected to the drying device (100), wherein the grinding device (200) grinds the white mud into white mud particles; The invention also comprises a screening device (300) for screening white mud particles, wherein the screening device (300) is provided with a first screen (321) and a second screen (322); the first screen (321) and the second screen (322) are provided with different filter hole diameters and are arranged at an angle; the first screen (321) and the second screen (322) are provided with a first outlet (323) and a second outlet (324) at the bottom, respectively, and the first outlet (323) and the second outlet (324) are connected to the decarbonization device and the grinding device (200) respectively; The first mixing and the second mixing of the white mud are respectively carried out by a mixing mechanism (400) and a ball mill (500); wherein the decarbonization equipment and the calcination equipment are operated by the same equipment.

7. The harmless treatment device for white mud according to claim 6 is characterized in that: The drying device (100) is provided with a base (110) and a drying body (120) supported by the base (110); a heat supply cavity (123) is provided between an outer shell (121) and an inner shell (122) of the drying body (120); the inner shell (122) is provided in a through-type manner to form a drying cavity (124); a plurality of evenly distributed heat supply pipes (126) are provided in the heating cavity (123); a plurality of heat conducting plates (125) are further provided in the drying cavity (124); the plurality of heat conducting plates (125) are provided in a spiral shape, and a white mud flow channel (127) is provided between adjacent heat conducting plates (125); The heat supply pipe (126) transfers heat to the inner shell (122) and the drying chamber (124) and the heat conducting sheet (125) in the drying chamber (124) by means of heat transfer; The base (110) is provided with a rotating part (130) for supporting the drying body (120) and a driving part (140) for driving the drying body (120).

8. The harmless treatment device for white mud according to claim 6 is characterized in that: The screening device (300) comprises a frame (310) and a screening part (320) arranged on the frame (310); the first screen (321) and the second screen (321) are adjacently arranged on the screening part (320); The first screen (321) is arranged at a higher end of the screening part (320), and the second screen (321) is arranged at a lower end of the screening part (320).

9. The harmless treatment device for white mud according to claim 8, characterized in that: The screening part (320) further comprises a screening frame (330) arranged on the first screen (321) and the second screen (322); The screening frame (330) is driven by a motor and slides based on the two ends of the frame (310). When sliding, the screening frame (330) performs a second crushing and squeezing on the fallen white mud particles, so that the white mud particles pass through the first screen (321) and / or the second screen (322).

10. The harmless treatment device for white mud according to claim 6, characterized in that: The decarburization equipment and the calcination equipment both use a rotary kiln (600) to perform decarburization and calcination operations; The rotary kiln (600) comprises a rotary body (610), wherein an installation area and an operation chamber (612) are adjacently arranged inside the rotary body (610); a plurality of guide plates (615) are arranged inside the operation chamber (612); A feeding mechanism (620) is also provided on the plurality of guide plates (615) in the working chamber (612); the feeding mechanism (620) comprises a sleeve (621) provided on the plurality of guide plates (615), and a feeding bin (622) provided inside the sleeve (621); a feeding auger (625) rotating based on two ends of the feeding bin (622) is provided in the feeding bin (622); The two ends of the working chamber (612) are respectively a first feed end (613) and a first discharge end (614); the two ends of the feed bin (622) are respectively a second feed end (623) and a second discharge end (624), and the feed bin (622) extends from the first discharge end (614) to the first feed end (613).

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