Process for reducing papermaking white mud and then preparing papermaking white mud into calcium oxide and related calcining equipment

Abstract

The invention discloses a technology for reducing papermaking white mud and then preparing the papermaking white mud into calcium oxide and related calcining equipment, relates to the technical field of preparation of calcium oxide through reduction of white mud, and solves the problems that in the prior art, drying efficiency is low, energy consumption is high, the white mud is prone to hardening, and calcining and discharging are inconvenient. A calcining mechanism is arranged on the right side of the top of the base. Through cooperation of the mechanisms and the process, resource utilization of the white mud is achieved, the white mud generated by sewage treatment of a paper mill is reduced to be prepared into calcium oxide, and solid waste discharge pollution is reduced; a process closed loop is formed, reduced calcium oxide is reused for sewage treatment, raw material purchase is reduced, calcination waste heat is used for white mud drying, and the treatment cost is reduced; the structural design is optimized, the drying mechanism increases the contact area of white mud and hot air, caking crushing, feeding and drying are efficiently linked, the calcining mechanism automatically unloads, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of calcium oxide preparation by reduction of white mud, specifically to a process and related calcination equipment for reducing papermaking white mud to prepare calcium oxide. Background Technology

[0002] In the paper industry, the use of calcium oxide for wastewater treatment produces a large amount of papermaking sludge, which is mainly composed of calcium carbonate and contains small amounts of organic matter, aluminosilicates and heavy metals. Traditional open-air dumping or landfilling methods not only occupy land but may also lead to pollution problems such as soil alkalization and heavy metal migration.

[0003] Existing technologies for the resource utilization of white clay have many shortcomings, such as low resource utilization rate. In traditional processes, white clay is mostly treated as waste, and when it is used in brick making, road paving, etc., it is difficult to apply on a large scale due to insufficient purity of calcium carbonate and high processing costs. The calcination process has significant energy consumption and pollution. Traditional rotary kilns waste a lot of heat energy and have low equipment efficiency. In the drying process, the white clay has a small contact area with hot air, takes a long time, and is prone to caking, which affects the uniformity of subsequent calcination. The process lacks a closed loop, and enterprises have to bear the costs of white clay treatment and calcium oxide procurement at the same time, resulting in a heavy economic burden. The unloading process relies on manual operation, which is time-consuming and has low production efficiency.

[0004] To this end, this invention proposes a process and related calcination equipment for the reduction of papermaking sludge to prepare calcium oxide. Through structural innovation and process integration, it fills the technological gaps in efficient drying, energy recycling and automated unloading, and provides a systematic solution for the resource utilization of sludge in the papermaking industry. Summary of the Invention

[0005] The purpose of this invention is to provide a process and related calcination equipment for reducing papermaking sludge and preparing calcium oxide, in order to solve the following technical problems:

[0006] Existing technologies suffer from problems such as low drying efficiency, high energy consumption, easy caking of white mud, and inconvenient unloading during calcination.

[0007] The objective of this invention can be achieved through the following technical solution: a calcination device for reducing and reprocessing papermaking sludge into calcium oxide, comprising a base, a drying mechanism provided on the top left side of the base, and a calcination mechanism provided on the top right side of the base;

[0008] The drying mechanism includes a base plate, with sliding plates fixedly connected to the front and rear ends of the bottom of the base plate. Multiple rollers are rotatably connected inside the front and rear ends of the bottom of the two sliding plates. Guide rails are slidably connected to the inner sides of the bottom of the two sliding plates. A fixed seat is provided on the left side of the inner side of the two guide rails. An electric telescopic rod is fixedly connected inside the fixed seat. A feeding component is provided on the top of the base plate. A drying component is provided on the left side of the inner side of the feeding component. The two guide rails are respectively fixedly connected to the front and rear ends of the top left side of the base. The bottom of the fixed seat is fixedly connected to the top left side of the base.

[0009] As a further embodiment of the present invention, a sliding groove is provided on the top left side of the base at a position corresponding to the front and rear ends of the two guide rails, and the bottoms of the plurality of rollers are respectively slidably connected to the interior of the corresponding sliding groove.

[0010] As a further embodiment of the present invention, the feeding component includes a holding hopper, a cover plate fixedly connected to the top left side of the holding hopper, a guide plate fixedly connected to the bottom left side of the holding hopper, a vertical pipe fixedly connected to the inside right side of the holding hopper, a discharge pipe fixedly connected to the top right side of the outer wall of the vertical pipe, a first motor threadedly connected to the top of the vertical pipe via a flange, a spiral lifting rod rotatably connected inside the vertical pipe, and the top end of the spiral lifting rod being locked together with the output shaft at the bottom of the first motor via a coupling, the holding hopper being fixedly connected to the top of the base plate, and the telescopic end on the right side of the electric telescopic rod being fixedly connected to the bottom left side of the holding hopper.

[0011] As a further embodiment of the present invention, a feeding port is pre-set on the left side of the bottom end of the outer wall of the vertical tube, and the top right side of the outer wall of the vertical tube is connected to the discharge pipe.

[0012] As a further embodiment of the present invention, the drying component includes a drying tank, a feeding port is provided on the top left side of the drying tank, a second motor is threadedly connected to the top center of the drying tank via a flange, a transmission rod is rotatably connected to the top of the drying tank, a spiral blade is fixedly connected to the outer wall of the transmission rod, a crushing blade is fixedly connected to the bottom of the outer wall of the transmission rod, a blocking barrel is fixedly connected to the bottom of the inner wall of the drying tank, the drying tank is fixedly connected to the inner center of the cover plate, and the output shaft at the bottom of the second motor is fixedly connected to the top of the transmission rod.

[0013] As a further embodiment of the present invention, the drying component further includes a crossbar, a return spring sleeved on the outer wall of the crossbar, a sliding sleeve sleeved on the right side of the outer wall of the crossbar, an insert plate fixedly connected to the bottom of the sliding sleeve, a handle fixedly connected to the left side of the insert plate, a baffle fixedly connected to the right side of the insert plate, the left side of the crossbar fixedly connected to the left side of the inner wall of the holding hopper, the left and right sides of the return spring being fixedly connected to the left side of the inner wall of the holding hopper and the left side of the sliding sleeve respectively, the insert plate being slidably connected inside the left side of the holding hopper, and the top end of the baffle being fastened to the bottom of the drying tank.

[0014] As a further embodiment of the present invention, the bottom radius of the spiral blade is smaller than the top radius, thereby making the entire spiral blade have an umbrella-like shape.

[0015] As a further embodiment of the present invention, the calcination mechanism includes a lower shaft plate, an upper shaft plate is provided on the top of the lower shaft plate, and the right sides of the lower shaft plate and the upper shaft plate are rotatably connected together by a pin. A rotary kiln is fixedly connected to the top of the upper shaft plate. Fixing ears are fixedly connected to the left side of the front surface and the back of the rotary kiln. A hydraulic strut is fixedly connected to the bottom of each fixing ear. A hot gas recovery pipe is threadedly connected to the center of the front surface and the center of the back of the rotary kiln through a flange. A connecting pipe is connected to the left side of each of the two hot gas recovery pipes. The lower shaft plate is fixedly connected to the top right side of the base, and the left side of the connecting pipe is connected to the drying tank.

[0016] A process for reducing and reprocessing papermaking sludge into calcium oxide includes the following steps:

[0017] Step 1: Reduce the water content of the white sludge produced after the treatment of calcium oxide wastewater in the paper mill by using a filter press or centrifuge.

[0018] Step 2: After completing the pretreatment of the white mud, the dehydrated white mud is put into the drying component of the drying mechanism. Through the operation of the drying component, the pretreated white mud can be dried and further removed.

[0019] Step 3: After the white clay is dried, it will fall into the hopper of the feeding component. The dried white clay can be piled up to the bottom left of the vertical pipe by the operation of the guide plate. The white clay can be lifted and transported to the discharge pipe by the operation of the spiral lifting rod, and then the dried white clay is put into the rotary kiln through the discharge pipe.

[0020] Step 4: After the dried white clay is put into the rotary kiln, the main component of the white clay, calcium carbonate, can be decomposed into calcium oxide and carbon dioxide through calcination in the rotary kiln, thereby completing the calcination and reduction of the white clay.

[0021] Step 5: After the calcined calcium oxide is cooled down, it is stored in a container. The reduced calcium oxide can be reused in papermaking wastewater treatment, forming a cycle. Through this process, paper mills can realize the resource utilization of white mud, thereby reducing treatment costs and environmental impact.

[0022] The beneficial effects of this invention are:

[0023] (1) Realize the resource utilization of white mud and reduce environmental pressure: the white mud produced by the wastewater treatment of paper mills is reduced and then prepared into calcium oxide, turning white mud into a treasure, effectively reducing the pollution caused by the discharge of white mud solid waste to the environment, and realizing the recycling of industrial waste.

[0024] (2) Forming a closed-loop process and reducing production costs: The reduced calcium oxide can be reused in papermaking wastewater treatment, forming a recycling system, reducing the company's purchase of external calcium oxide raw materials and reducing raw material costs; at the same time, the waste heat generated by the calcination mechanism is transported to the drying tank through the hot gas recovery pipe and connecting pipe to provide heat for white mud drying, which can realize the resource utilization of white mud, reduce treatment costs and reduce environmental impact.

[0025] (3) Optimize structural design and improve production efficiency: The design of umbrella-shaped spiral blades in the drying mechanism increases the contact area between white mud and hot air, accelerates the drying process, and the crushing blades can break up the white mud that has been clumped together after drying, which is convenient for subsequent calcination; the feeding component and the drying component work together to achieve efficient connection between white mud drying and conveying; the hydraulic struts in the calcination mechanism drive the rotary kiln to tilt and unload, which has a high degree of automation, avoids movement obstruction during unloading, and improves unloading efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the connection structure of the calcination equipment for reducing and reprocessing papermaking sludge into calcium oxide according to the present invention;

[0027] Figure 2 This is the present invention. Figure 1 Another isometric connection structure diagram;

[0028] Figure 3 This is the present invention. Figure 1 A front view diagram of the connection structure;

[0029] Figure 4 This is the present invention. Figure 1 Schematic diagram of the connection structure of the calcination mechanism;

[0030] Figure 5 This is the present invention. Figure 1 Schematic diagram of the connection structure of the drying mechanism;

[0031] Figure 6 This is the present invention. Figure 5 A schematic diagram of the connection structure viewed from below;

[0032] Figure 7 This is the present invention. Figure 5 Another axonometric partial sectional view of the connection structure;

[0033] Figure 8 This is the present invention. Figure 7 A frontal cross-sectional view of the connection structure.

[0034] In the diagram: 1. Base; 2. Drying mechanism; 201. Base plate; 202. Slide plate; 203. Roller; 204. Guide rail; 205. Fixed seat; 206. Electric telescopic rod; 207. Feeding component; 2071. Holding hopper; 2072. Cover plate; 2073. Guide plate; 2074. Vertical pipe; 2075. Discharge pipe; 2076. First motor; 207. Spiral lifting rod; 208. Drying component; 2081. Drying tank; 2082. Feeding port; 208... 3. Second motor; 2084. Transmission rod; 2085. Spiral blade; 2086. Crushing blade; 2087. Blocking barrel; 2088. Crossbar; 2089. Return spring; 20810. Sliding sleeve; 20811. Insert plate; 20812. Handle; 20813. Baffle; 3. Calcination mechanism; 301. Lower shaft plate; 302. Upper shaft plate; 303. Rotary furnace; 304. Fixing lug; 305. Hydraulic strut; 306. Heat recovery pipe; 307. Connecting pipe. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1, please refer to Figure 1 and Figures 5-8 As shown, the present invention is a calcination device for reducing and reprocessing papermaking sludge into calcium oxide, comprising a base 1, which is used to install a drying mechanism 2 and a calcination mechanism 3. The drying mechanism 2 is provided on the top left side of the base 1, which is used to dry the sludge after preliminary treatment, further reducing the water content in the sludge to facilitate subsequent calcination processing. The calcination mechanism 3 is provided on the top right side of the base 1, which is used to calcine the dried sludge, thereby reducing the calcium carbonate in the sludge into calcium oxide.

[0037] The drying mechanism 2 includes a base plate 201, which is used to fix the feeding component 207. Slide plates 202 are fixedly connected to the front and rear ends of the bottom of the base plate 201. The slide plates 202 are used to drive the base plate 201 to slide on top of the guide rail 204. Multiple rollers 203 are rotatably connected inside the front and rear ends of the bottom of the two slide plates 202. The rollers 203 are used to reduce the friction between the slide plates 202 and the base plate 201, thereby facilitating the movement of the slide plates 202. Guide rails 204 are slidably connected to the inner bottom of the two slide plates 202. The guide rails 204 are used to limit the movement trajectory and stroke of the slide plates 202. A fixing seat 205 is provided on the inner left side of the two guide rails 204. The fixing seat 205 is used to fix the electric telescopic rod 206. The electric telescopic rod 206 is fixedly connected inside the fixing seat 205. The electric telescopic rod 206 is used to drive the feeding component 207. The 7th movement allows the feeding component 207 to slide to the left, thereby removing the discharge pipe 2075, which was originally inserted into the left side of the rotary kiln 303 in the calcination mechanism 3, from its interior. This facilitates the subsequent discharge of calcium oxide that has been calcined and reduced inside the rotary kiln 303, preventing obstruction of movement between the discharge pipe 2075 and the calcium oxide during discharge from the calcination mechanism 3. The top of the base plate 201 is equipped with a feeding component 207, which is used to feed the dried white clay into the interior of the calcination mechanism 3. The left side of the inside of the feeding component 207 is equipped with a drying component 208, which is used to dry the white clay that has undergone preliminary dehydration treatment, facilitating subsequent processing of the white clay. Two guide rails 204 are fixed to the front and rear ends of the top left side of the base 1, respectively, and the bottom of the fixed seat 205 is fixed to the top left side of the base 1.

[0038] In this embodiment, preferably, a groove is provided on the top left side of the base 1 at the position corresponding to the front and rear ends of the two guide rails 204, and the bottoms of the multiple rollers 203 are slidably connected to the inside of the corresponding groove.

[0039] In this embodiment, preferably, the feeding component 207 includes a holding hopper 2071 for collecting the dried white clay. A cover plate 2072 is fixedly connected to the top left side of the holding hopper 2071 for fixing the drying component 208. A guide plate 2073 is fixedly connected to the bottom left side of the inner side of the holding hopper 2071 for guiding the white clay discharged from the drying component 208, so that the white clay can flow to the bottom left side of the outer wall of the vertical pipe 2074, so that the spiral lifting rod 2077 can lift and transport the dried white clay. A vertical pipe 2074 is fixedly connected to the inner right side of the holding hopper 2071 for surrounding the spiral lifting rod 207. A discharge pipe 2075 is fixedly connected to the top right side of the outer wall of the vertical pipe 2074. 2075 is used to discharge the white mud that has been lifted and conveyed to the top of the vertical rod by the screw lifting rod 207, so that the dried white mud can be discharged into the rotary kiln 303. The top of the vertical tube 2074 is connected to the first motor 2076 by a flange thread. The first motor 2076 is used to provide power to the screw lifting rod 207, so that it can rotate inside the vertical tube 2074. The screw lifting rod 207 is rotatably connected inside the vertical tube 2074. The screw lifting rod 207 is used to lift and convey the dried white mud. The top of the screw lifting rod 207 is locked together with the output shaft at the bottom of the first motor 2076 by a coupling. The container 2071 is fixed to the top of the bottom plate 201. The telescopic end on the right side of the electric telescopic rod 206 is fixedly connected to the bottom left side of the container 2071.

[0040] In this embodiment, preferably, a feeding port is pre-set on the left side of the bottom end of the outer wall of the vertical pipe 2074. By opening a feeding port on the left side of the bottom end of the outer wall of the vertical pipe 2074, it is convenient to lift and transport the white mud piled in the holding hopper 2071. The top right side of the outer wall of the vertical pipe 2074 is connected to the discharge pipe 2075.

[0041] In this embodiment, preferably, the drying component 208 includes a drying tank 2081, which is used to hold the white mud that has undergone preliminary dehydration treatment. A feeding port 2082 is provided on the top left side of the drying tank 2081, through which the dehydrated white mud can be fed into the drying tank 2081. A second motor 2083 is threadedly connected to the top center of the drying tank 2081 via a flange. The second motor 2083 provides power to the transmission rod 2084, enabling the transmission rod 2084 to rotate inside the drying tank 2081. The transmission rod 2084 is rotatably connected to the top of the drying tank 2081. The transmission rod 2084 drives the spiral blade 2085 and the crushing blade 2086 to rotate. The spiral blade 2085 is fixedly connected to the outer wall of the transmission rod 2084. 2085 is used to spray the white mud fed into the drying tank 2081, so that the white mud can be dried quickly. The bottom of the outer wall of the transmission rod 2084 is fixed with a crushing blade 2086. The crushing blade 2086 is used to stir the dried white mud discharged from the drying tank 2081, which can break up the white mud that has hardened into lumps after drying, so as to facilitate subsequent calcination and reduction. The bottom of the inner wall of the drying tank 2081 is fixed with a blocking bucket 2087. The blocking bucket 2087 is used to surround the white mud fed into the drying tank 2081, so that the white mud can be gathered to the bottom of the inner wall of the drying tank 2081, so that the spiral blade 2085 can lift and spray the white mud. The drying tank 2081 is fixed at the center of the inner wall of the cover plate 2072. The output shaft at the bottom of the second motor 2083 is fixedly connected to the top of the transmission rod 2084.

[0042] In this embodiment, preferably, the drying component 208 further includes a crossbar 2088, which limits the movement trajectory of the sliding sleeve 20810 and supports it. A return spring 2089 is sleeved on the outer wall of the crossbar 2088, which compresses the sliding sleeve 20810. After the sliding sleeve 20810 slides to the left side of the crossbar 2088, the pull on the handle 20812 is released, and the sliding sleeve 20810 can be reset. The sliding sleeve 20810 is sleeved on the right side of the outer wall of the crossbar 2088, which supports the right side of the insert plate 20811. The bottom of the sliding sleeve 20810 is fixedly connected to the insert plate 20811, which supports the baffle 2081. 3. The baffle 20813 is fixed and can move, thereby removing the barrier between the insert plate 20811 and the bottom of the drying tank 2081. A handle 20812 is fixed to the left side of the insert plate 20811 and is used to move the insert plate 20811. A baffle 20813 is fixed to the right side of the insert plate 20811 and is used to block the bottom of the drying tank 2081. The left side of the crossbar 2088 is fixed to the left side of the inner wall of the container 2071. The left and right sides of the return spring 2089 are fixedly connected to the left side of the inner wall of the container 2071 and the left side of the sliding sleeve 20810, respectively. The insert plate 20811 is slidably connected to the inside of the left side of the container 2071. The top of the baffle 20813 is fastened to the bottom of the drying tank 2081.

[0043] In this embodiment, preferably, the bottom radius of the spiral blade 2085 is smaller than the top radius, so that the entire spiral blade 2085 is arranged in an umbrella shape. During the rotation of the spiral blade 2085, the white mud at the bottom of the drying tank 2081 can be lifted and transported to its top. After the white mud is lifted to the top of the spiral blade 2085, it will be thrown out in an umbrella shape, which facilitates the drying of the white mud and makes the white mud dry more evenly, reducing the phenomenon of the dried white mud caking into lumps.

[0044] In summary, the preliminarily dehydrated white mud is fed into the drying tank 2081 through the top feeding port 2082. The second motor 2083 drives the transmission rod 2084 to rotate the umbrella-shaped spiral blade 2085, lifting the white mud from the bottom center of the drying tank 2081 to the top and then scattering it in an umbrella shape to increase the contact area with hot air and accelerate drying. At the same time, the crushing blade 2086 at the bottom of the transmission rod 2084 agitates the dried white mud and breaks up any clumps that may have hardened. After drying is completed, pulling the handle 20812 moves the insert plate 20811, causing the baffle 20813 to detach from the drying tank 2081. At the bottom, the white clay falls into the holding hopper 2071 under the action of gravity. It is guided by the guide plate 2073 to the feeding port on the left side of the bottom of the outer wall of the vertical pipe 2074. At this time, the first motor 2076 drives the spiral lifting rod 207 inside the vertical pipe 2074 to rotate, lifting the white clay from the feeding port and sending it into the calcination mechanism 3 through the top discharge pipe 2075 on the right side of the outer wall of the vertical pipe 2074. After the unloading is completed, the handle 20812 is released, and the reset spring 2089 pushes the sliding sleeve 20810 to drive the baffle 20813 to re-lock the bottom of the drying tank 2081, realizing the efficient connection between white clay drying and conveying.

[0045] Example 2, please refer to Figures 1-4As shown, based on Embodiment 1, the calcination mechanism 3 includes a lower shaft plate 301, with an upper shaft plate 302 positioned on top of the lower shaft plate 301. The upper shaft plate 302 is used to fix and install the rotary kiln 303. The upper shaft plate 302 can rotate and open and close with the right side of the lower shaft plate 301 as its axis. The right sides of the lower shaft plate 301 and the upper shaft plate 302 are rotatably connected together by a pin. The rotary kiln 303 is fixedly connected to the top of the upper shaft plate 302. The rotary kiln 303 is used to calcine and reduce the dried white clay, so that... After calcination, the calcium carbonate in the white clay decomposes into calcium oxide and carbon dioxide. Fixing lugs 304 are fixed to the front surface and the left side of the back of the rotary kiln 303 to secure the top of the hydraulic struts 305. By using the fixing lugs 304, when the hydraulic struts 305 are raised, the left side of the rotary kiln 303 is also raised, causing the rotary kiln 303 to tilt, facilitating the discharge of calcium oxide from its interior. A hydraulic strut 305 is fixed to the bottom of each fixing lug 304. 05. The hydraulic strut 305 is used to move the left side of the rotary kiln 303. Both the center of the front surface and the center of the back surface of the rotary kiln 303 are connected to a heat recovery pipe 306 via a flange thread. The heat recovery pipe 306 is used to recover the waste heat generated during the calcination of white clay in the rotary kiln 303. A connecting pipe 307 is connected to the left side of each heat recovery pipe 306. The connecting pipe 307 connects the heat recovery pipe 306 to the drying tank 2081, thereby recovering the waste heat. The collected hot air is transported to the inside of the drying tank 2081 to dry the white mud inside the drying tank 2081. The lower shaft plate 301 is fixed to the top right side of the base 1. The left side of the connecting pipe 307 is connected to the drying tank 2081. The middle section of the connecting pipe 307 is spring-shaped, so that the connecting pipe 307 as a whole has a certain elasticity. When the drying mechanism 2 moves to the left, the connecting pipe 307 will not separate from the drying tank 2081, so that hot air can be continuously transported into the drying tank 2081.

[0046] In summary, the dried white mud is calcined at high temperature in the rotary kiln 303, utilizing the chemical reaction of calcium carbonate decomposition at high temperature to decompose the calcium carbonate in the white mud into calcium oxide and carbon dioxide. In the unloading stage, firstly, the electric telescopic rod 206 in the drying mechanism 2 drives the feeding component 207 to slide to the left, so that the discharge pipe 2075 slides out from the left side of the rotary kiln 303. Then, the hydraulic support rod 305 is connected to the rotary kiln 303 through the fixed lug 304. When it is supported upward, it drives the left side of the rotary kiln 303 to rise, so that it rotates and tilts with the right side of the lower shaft plate 301 as the axis, thereby discharging the calcium oxide by gravity. In terms of heat recovery, the high-temperature gas generated by the rotary kiln 303 is collected by the heat recovery pipe 306 and transported to the drying tank 2081 through the elastic spring-shaped connecting pipe 307 to provide heat for drying the white mud in the drying tank 2081, realizing the energy cycle from calcination waste heat to drying heat supply.

[0047] Example 3, please refer to Figures 1-8 As shown, this embodiment combines Example 1 and Example 2 to obtain the calcination equipment for reducing and reprocessing papermaking sludge into calcium oxide. The equipment mainly consists of a drying mechanism 2 and a calcination mechanism 3. The sludge after preliminary dehydration is fed into the feeding port 2082 at the top of the drying tank 2081. The second motor 2083 drives the transmission rod 2084 to rotate, which in turn drives the umbrella-shaped spiral blades 2085 on the outer wall of the transmission rod 2084 to rotate. The bottom radius of the spiral blades 2085 is smaller than the top radius. During the rotation, the sludge located at the bottom center of the drying tank 2081 is lifted to the top and scattered in an umbrella shape, increasing the contact area between the sludge and the hot air and accelerating the drying process. At the same time, the breaking blades 2086 at the bottom of the transmission rod 2084 agitate the dried sludge and break up any clumps of sludge that may have hardened, making it easier for subsequent calcination and reduction.

[0048] After drying, pull handle 20812 to move insert plate 20811. Insert plate 20811 moves baffle 20813 away from the bottom of drying tank 2081. White mud falls into holding hopper 2071 under gravity. Guide plate 2073 in holding hopper 2071 guides the falling white mud to flow to the feeding port on the left side of the bottom of the outer wall of vertical pipe 2074. At this time, first motor 2076 drives spiral lifting rod 207 in vertical pipe 2074 to rotate, lifting white mud from feeding port and sending it into rotary furnace 303 of calcination mechanism 3 through discharge pipe 2075 on the top right side of the outer wall of vertical pipe 2074. After unloading, release handle 20812. Reset spring 2089 pushes sliding sleeve 20810 to re-lock baffle 20813 at the bottom of drying tank 2081, completing one drying and conveying process.

[0049] After receiving the dried white mud from the drying mechanism 2, the rotary kiln 303 calcines the white mud at high temperature. Utilizing the chemical reaction of calcium carbonate decomposing at high temperature, the calcium carbonate in the white mud is decomposed into calcium oxide and carbon dioxide, realizing the core process of white mud reduction to prepare calcium oxide. In the unloading stage, the electric telescopic rod 206 in the drying mechanism 2 drives the feeding component 207 to slide to the left, so that the discharge pipe 2075 slides out from the left side of the rotary kiln 303, avoiding movement obstruction during unloading. Subsequently, the hydraulic support rods 305 at the bottom of the fixing ears 304 on the front surface and back of the rotary kiln 303 are raised upwards, and the left side of the rotary kiln 303 is raised together through the fixing ears 304, so that the rotary kiln 303 rotates and tilts with the right side of the lower shaft plate 301 as the axis, and uses gravity to discharge the calcium oxide inside the rotary kiln 303.

[0050] The high-temperature gas generated during the calcination of white clay in the rotary kiln 303 is collected by heat recovery pipes 306 located at the center of the front surface and the center of the back surface. A spring-shaped connecting pipe 307, connecting the left sides of the two heat recovery pipes 306, transports the recovered hot gas to the interior of the drying tank 2081, providing heat for the drying process of the white clay inside the drying tank 2081. This achieves an energy cycle from calcination waste heat to drying heat supply, reducing the overall energy consumption of the equipment.

[0051] Example 4, please refer to Figures 1-8 As shown, this invention also discloses a process for reducing papermaking sludge and preparing calcium oxide, comprising the following steps:

[0052] Step 1: Reduce the water content of the white sludge produced after the treatment of calcium oxide wastewater in the paper mill by using a filter press or centrifuge.

[0053] Step 2: After completing the pretreatment of the white mud, the dehydrated white mud is put into the drying component 208 in the drying mechanism 2. Through the operation of the drying component 208, the pretreated white mud can be dried and further removed from the moisture contained therein.

[0054] Step 3: After the white clay is dried, it will fall into the inside of the hopper 2071 in the feeding component 207. Through the operation of the guide plate 2073, the dried white clay can be piled to the bottom left side of the vertical pipe 2074. Through the operation of the spiral lifting rod 207, the white clay can be lifted and transported to the inside of the discharge pipe 2075, and the dried white clay can be fed into the rotary kiln 303 through the discharge pipe 2075.

[0055] Step 4: After the dried white mud is put into the rotary kiln 303, the main component of the white mud, calcium carbonate, can be decomposed into calcium oxide and carbon dioxide through calcination in the rotary kiln 303, thereby completing the calcination and reduction of the white mud.

[0056] Step 5: After the calcined calcium oxide is cooled down, it is stored in a container. The reduced calcium oxide can be reused in papermaking wastewater treatment, forming a cycle. Through this process, paper mills can realize the resource utilization of white mud, thereby reducing treatment costs and environmental impact.

[0057] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A calcination apparatus for the reduction of paper white mud to produce calcium oxide, comprising a base, characterised in that, The top left side of the base is provided with a drying mechanism, and the top right side of the base is provided with a calcination mechanism; The drying mechanism comprises a bottom plate, the bottom front end and the rear end of the bottom plate are fixedly connected with sliding plates, the inner bottom front end and the inner bottom rear end of the two sliding plates are rotatably connected with a plurality of rollers, the inner bottom side of the two sliding plates is slidably connected with guide rails, the inner left side of the two guide rails is provided with a fixed seat, the inner side of the fixed seat is fixedly connected with an electric telescopic rod, the top of the bottom plate is provided with a feeding member, the inner left side of the feeding member is provided with a drying member, the bottom of the two guide rails is fixedly connected with the top left side front end and the top left side rear end of the base, and the bottom of the fixed seat is fixedly connected with the top left side of the base.

2. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 1, characterized in that, The top left side of the base is provided with a drying mechanism, and the top right side of the base is provided with a calcination mechanism; 3. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 1, characterized in that, The top left side of the base is provided with a drying mechanism, and the top right side of the base is provided with a calcination mechanism; 4. The calcining apparatus for producing calcium oxide from papermaking white mud reduced and re-produced according to claim 3, characterized in that, The top left side of the base is provided with a drying mechanism, and the top right side of the base is provided with a calcination mechanism; 5. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 1, characterized in that, The outer wall bottom left side of the vertical pipe is provided with a feeding port, and the outer wall right top of the vertical pipe is communicated with the discharge pipe.

6. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 5, characterized in that, The drying member comprises a drying tank, the top left side of the drying tank is provided with a feeding port, the top center of the drying tank is threadedly connected with a second motor through a flange, the inner top end of the drying tank is rotatably connected with a transmission rod, the outer wall of the transmission rod is fixedly connected with a spiral blade, the outer wall bottom end of the transmission rod is fixedly connected with a crushing blade, the inner wall bottom end of the drying tank is fixedly connected with a blocking barrel, the drying tank is fixedly connected in the inner center of the cover plate, and the bottom output shaft of the second motor is fixedly connected with the top of the transmission rod.

7. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 5, characterized in that, The outer wall of the vertical pipe is provided with a feeding port, and the outer wall right top of the vertical pipe is communicated with the discharge pipe. The drying member further comprises a horizontal rod, the outer wall of the horizontal rod is sleeved with a reset spring, the outer wall right side of the horizontal rod is sleeved with a sliding sleeve, the bottom of the sliding sleeve is fixedly connected with an insertion plate, the left side of the insertion plate is fixedly connected with a handle, the right side of the insertion plate is fixedly connected with a baffle, the left side of the horizontal rod is fixedly connected to the inner wall left side of the holding hopper, the left and right sides of the reset spring are fixedly connected with the inner wall left side of the holding hopper and the left side of the sliding sleeve respectively, the insertion plate is slidably connected in the left inner side of the holding hopper, and the top end of the baffle is buckled on the bottom of the drying tank. The bottom surface radius of the spiral blade is smaller than the top surface radius, so that the whole spiral blade is umbrella-shaped.

8. The calcining apparatus for reducing and re-preparing white mud of papermaking into calcium oxide according to claim 1, characterized in that, The calcination mechanism includes a lower shaft plate, with an upper shaft plate on top of the lower shaft plate. The lower shaft plate and the upper shaft plate are rotatably connected together on the right side by a pin. A rotary kiln is fixedly connected to the top of the upper shaft plate. Fixing lugs are fixedly connected to the left side of the front surface and the back of the rotary kiln. A hydraulic strut is fixedly connected to the bottom of each fixing lug. A hot gas recovery pipe is threadedly connected to the center of the front surface and the center of the back of the rotary kiln via a flange. A connecting pipe is connected to the left side of each of the two hot gas recovery pipes. The lower shaft plate is fixedly connected to the top right side of the base. The left side of the connecting pipe is connected to the drying tank.

9. A process for the re-production of calcium oxide from papermaking white mud, characterized in that, The calcination equipment for reducing and reprocessing papermaking sludge into calcium oxide as described in claim 1 includes the following steps: Step 1: Reduce the water content of the white sludge produced after the treatment of calcium oxide wastewater in the paper mill by using a filter press or centrifuge. Step 2: After completing the pretreatment of the white mud, the dehydrated white mud is put into the drying component of the drying mechanism. Through the operation of the drying component, the pretreated white mud can be dried and further removed. Step 3: After the white clay is dried, it will fall into the hopper of the feeding component. The dried white clay can be piled up to the bottom left of the vertical pipe by the operation of the guide plate. The white clay can be lifted and transported to the discharge pipe by the operation of the spiral lifting rod, and then the dried white clay is put into the rotary kiln through the discharge pipe. Step 4: After the dried white clay is put into the rotary kiln, the main component of the white clay, calcium carbonate, can be decomposed into calcium oxide and carbon dioxide through calcination in the rotary kiln, thereby completing the calcination and reduction of the white clay. Step 5: After the calcined calcium oxide is cooled down, it is stored in a container. The reduced calcium oxide can be reused in papermaking wastewater treatment, forming a cycle. Through this process, paper mills can realize the resource utilization of white mud, thereby reducing treatment costs and environmental impact.

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