A neutralization pulping device for phosphogypsum resource utilization
By simultaneously adding alkaline additives and rapidly stirring during the transportation of phosphogypsum powder, the problem of uneven mixing was solved, the stability of gypsum slurry and the molding quality of gypsum building materials were improved, and the effects of energy conservation, emission reduction and resource utilization were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEBEI UNIV OF TECH
- Filing Date
- 2025-07-31
- Publication Date
- 2026-08-04
AI Technical Summary
In the traditional neutralization process, the alkaline additives and phosphogypsum powder are not mixed evenly, resulting in unstable quality of building gypsum and additional energy consumption, which affects the molding quality of gypsum building materials.
Alkaline additives are added simultaneously during the conveying of building gypsum powder, and the powder is rapidly stirred and mixed in a mixer to ensure uniform mixing. The combination of a quantitative conveyor and a mixer achieves uniform mixing of the alkaline additives and gypsum powder.
It improves the stability of gypsum slurry, ensures the molding quality of gypsum building materials, reduces energy consumption, simplifies the production process, and improves the resource utilization efficiency of phosphogypsum.
Smart Images
Figure CN224588301U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a special equipment for the production of energy-saving and environmentally friendly building materials, and more particularly to a neutralization and pulping device for the resource utilization of phosphogypsum. Background Technology
[0002] Phosphogypsum is a solid derivative produced during the industrial production of phosphoric acid. Its main component is calcium sulfate dihydrate. Producing 1 ton of phosphoric acid generates 4.5 tons of phosphogypsum. Phosphoric acid is the main raw material for phosphate fertilizer production; therefore, the generation of phosphogypsum is unavoidable whenever phosphate fertilizer is produced. Although phosphogypsum is a large-scale industrial solid waste, its calcium sulfate dihydrate content exceeds 80%, thus giving it recycling value. The principle is that calcium sulfate dihydrate undergoes thermal treatment to convert to calcium sulfate hemihydrate, a commonly used building material, commonly known as calcined gypsum or building gypsum. Phosphogypsum contains various harmful phosphorus-based impurities and acidic impurities, which significantly negatively impact its resource utilization. It requires a specific thermal treatment process to remove these harmful impurities and neutralize the acidity before it can be used. The traditional neutralization process involves adding a certain proportion of alkaline additives such as calcium oxide or calcium hydroxide to the calcium sulfate hemihydrate in the silo. This is a separate process that often results in uneven mixing, compromising the quality of the building gypsum. Furthermore, this separate process requires additional energy.
[0003] The molding principle of gypsum building materials is that hemihydrate gypsum can undergo a hydration reaction when water is added to produce chemically stable solid calcium sulfate dihydrate. This principle can be used to cast and produce gypsum boards, gypsum blocks, molds and other gypsum profiles. The curing reaction of hemihydrate gypsum with water is very rapid, and it can be initially solidified from a highly fluid liquid in just tens of seconds. In such a short time, the neutralization uniformity of calcium sulfate hemihydrate is a key factor affecting the stability of gypsum slurry, which will have an important impact on the molding quality of gypsum building materials.
[0004] This patent designs an integrated neutralization and slurry preparation device for the resource utilization of phosphogypsum. During the conveying of building gypsum powder to the mixing and slurry preparation zone, an alkaline additive is simultaneously and uniformly added to a metering conveyor. When the building gypsum powder arrives at the tightly connected mixing and slurry preparation zone, it has already been uniformly mixed with the alkaline additive during the metering process. Water is then added in a mixer and rapidly stirred to prepare the slurry, ensuring the uniformity and stability of the gypsum slurry. This slurry is then poured into molds for casting, guaranteeing the molding quality of the gypsum building materials. This patent represents an innovative energy-saving, emission-reduction, and green recycling technology that significantly improves the efficiency of phosphogypsum neutralization and slurry preparation, enhances the utilization benefits of phosphogypsum, and reduces solid waste emissions. Summary of the Invention
[0005] A neutralization and pulping device for the resource utilization of phosphogypsum includes a silo, a first transverse conveyor, an elevator, a second transverse conveyor, a neutralization and proportioning zone, a mixing and pulping zone, a ground surface, and a workshop. The silo is a hollow structure with a cylindrical upper section and a conical lower section, with an inlet at the top and an outlet and valve at the bottom. The silo, the first transverse conveyor, and the elevator are located on the ground outside the workshop. The inlet of the first transverse conveyor is connected to the outlet and valve of the silo, and the outlet of the first transverse conveyor is connected to the inlet at the bottom of the elevator. The elevator is a vertical elevator, with its inlet below the ground level and its outlet above the top of the workshop. The second transverse conveyor is located on the roof of the workshop, and its inlet is connected to the outlet of the elevator. The workshop is divided into two levels: the upper level is the neutralization and proportioning zone, and the lower level is the mixing and pulping zone.
[0006] The neutralization and proportioning zone includes: a quantitative conveyor, a transfer silo, a screening machine, a solid additive silo, a metering valve, a distribution silo, a process water silo, a liquid additive silo, and a fiberglass silo. The quantitative conveyor is a horizontal conveying structure, located on the bottom surface of the upper layer. It has two feed inlets, left and right, at its upper part. The transfer silo is located above the left feed inlet, and the screening machine is located above the transfer silo. The feed inlet of the transfer silo connects to the discharge port of the screening machine, and its discharge port connects to the left feed inlet of the quantitative conveyor. The feed inlet of the screening machine extends from the top of the workshop and connects to the discharge port of the second horizontal conveyor. The solid additive silo is located above the right feed inlet of the quantitative conveyor. The discharge port of the solid additive silo and the right feed inlet of the quantitative conveyor are connected by a metering valve. The metering valve controls the addition ratio of solid additives; different proportions of alkaline additives are required for different acidic building gypsum powders.
[0007] A further embodiment is that the process water tank and the fiberglass tank are located on the right side of the quantitative conveyor, and the liquid additive tank is located above the process water tank. The two are connected by a flow control valve and pipelines; the process water tank is connected to an external water supply pipe through the flow control valve and pipelines.
[0008] A further embodiment includes the following internal components in the mixing and pulping zone: a water spray pipe, a powder adding pipe, a water adding pipe, a guide plate, a splash guard, a fiberglass adding pipe, a mixer, molds, and a rotary frame. The rotary frame serves as the rotational track for the molds. Multiple molds are connected end-to-end by chains and are rotatably mounted on a circular track on the rotary frame. The chains are connected to a drive motor. The mixer is a rotary mixing pulping machine structure, with six mixing tanks fixed around a circular rotating platform, evenly distributed into six workstations: a cleaning workstation, a water adding workstation, a powder adding workstation, a fiberglass adding workstation, a mixing workstation, and a grouting workstation. The mixing tank at the grouting workstation is located directly above one of the molds on the rotary frame. The circular rotating platform is connected to... Driven by a rotary motor, it can drive six mixing tanks to rotate intermittently around the center. Each mixing tank is equipped with a gate valve on its bottom surface. The water spray pipe is connected to a water pump, and the water spray nozzle is located above the mixing tank at the cleaning station. The guide plate is inclinedly set below the mixing tank at the cleaning station. The material distribution bin is located between the neutralization and proportioning zone and the mixing and pulping zone. The upper inlet is connected to the outlet of the quantitative conveyor, and the lower outlet is connected to the powder adding pipe. The lower outlet of the powder adding pipe is located above the mixing tank at the powder adding station. The upper end of the water adding pipe is connected to the process water tank, and the lower outlet is located above the mixing tank at the water adding station. The upper end of the glass fiber adding pipe is connected to the outlet of the glass fiber silo, and the lower outlet is located above the mixing tank at the glass fiber adding station.
[0009] A further option is to use a propeller conveying structure for the quantitative conveyor.
[0010] A further solution is to fix a splash guard between the mixing tank at the grouting station and the mold.
[0011] A further solution is to install flow control valves on the water spray pipe and water inlet pipe, and metering control valves on the powder inlet pipe and fiberglass inlet pipe. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure; Figure 2 This is a schematic diagram of the workshop's internal structure. Figure 3 This is a top view of the mixing and pulping area; Figure 4 This is a schematic diagram of a quantitative conveyor. Detailed Implementation
[0013] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.
[0014] A neutralization and pulping device for the resource utilization of phosphogypsum, such as Figure 1As shown, the facility includes a silo 1, a first transverse conveyor 2, an elevator 3, a second transverse conveyor 4, a neutralization and proportioning zone 5, a mixing and pulping zone 6, a ground level 7, and a workshop 8. The silo 1 is a hollow structure with a cylindrical upper section and a conical lower section, with an inlet at the top and an outlet and valve at the bottom. The silo 1, the first transverse conveyor 2, and the elevator 3 are located on the ground level outside the workshop 8. The inlet of the first transverse conveyor 2 connects to the outlet and valve of the silo 1, and the outlet of the first transverse conveyor 2 connects to the inlet at the bottom of the elevator 3. The elevator 3 is a vertical lifting mechanism. The feed inlet of the elevator 3 is located below the ground level, so as to receive the material from the first transverse conveyor 2 stably by gravity. The discharge outlet is above the top of the workshop, so as to feed the material to the second transverse conveyor stably by gravity. The second transverse conveyor 4 is located on the roof of the workshop, and the feed inlet of the second transverse conveyor 4 is connected to the discharge outlet of the elevator 3. The workshop is divided into two layers. The upper layer is the neutralization and proportioning zone 5, and the lower layer is the mixing and pulping zone 6. The purpose of dividing it into upper and lower layers is to realize the gravity falling of various raw materials. Otherwise, an additional conveying power device would be required.
[0015] The internal structure of the neutralization and proportioning zone 5 is as follows: Figure 2 As shown, it includes: a quantitative conveyor 51, a transfer bin 52, a screening machine 53, a solid additive bin 54, a metering valve 55, a distribution bin 56, a process water bin 57, a liquid additive bin 58, and a fiberglass bin 59; the quantitative conveyor 51 is a horizontal conveying structure, set on the bottom surface of the neutralization and proportioning zone 5, as shown. Figure 4 As shown, the quantitative conveyor 51 has two feed inlets, one on the left and one on the right, at its upper part. The transfer chamber 52 is located above the left feed inlet, and the screening machine 53 is located above the transfer chamber 52. The feed inlet of the transfer chamber 52 is connected to the discharge port of the screening machine 53, and the discharge port of the transfer chamber 52 is connected to the left feed inlet of the quantitative conveyor 51. The feed inlet of the screening machine 53 extends out of the top of the workshop and connects to the discharge port of the second transverse conveyor 4. The screening machine 53 can remove slightly larger particles or trace amounts of solidified gypsum dihydrate from the building gypsum powder. The transfer chamber 52 is set up to maintain a stable supply to the quantitative conveyor 51 and to keep a certain amount of material in the transfer chamber. In this way, when the external feeding equipment is unstable for a short period of time, the transfer chamber 52 can maintain a stable supply to the quantitative conveyor 51 for a certain period of time.
[0016] The solid additive bin 54 is positioned above the right inlet of the metering conveyor 51, and the outlet of the solid additive bin 54 and the right inlet of the metering conveyor 51 are connected via a metering valve 55. The solid additive is an alkaline powder such as calcium oxide or calcium hydroxide. After being added to the metering conveyor 51, it mixes with the building gypsum powder and continues to be conveyed towards the outlet. The metering conveyor 51 is preferably a propeller-type metering conveyor, which facilitates thorough mixing of the alkaline additive and the building gypsum powder during the spiral rotation conveying process.
[0017] The process water tank 57 and the fiberglass tank 59 are located on the right side of the quantitative conveyor 51. The liquid additive tank 58 is located above the process water tank 57 and is connected by a set of flow control valves and pipelines. The process water tank 57 is connected to an external water supply pipe through another set of flow control valves and pipelines. Liquid additives such as coagulants or retarders are added to the process water tank in proportion, which simplifies the device structure and makes it easy to mix evenly.
[0018] The mixing and pulping zone 6 includes: a water spray pipe 61, a powder adding pipe 62, a water adding pipe 63, a guide plate 64, a splash guard 65, a fiberglass reinforced pipe 66, a mixer 67, a mold 68, and a rotary frame 69. The rotary frame 69 serves as the rotary motion track for the mold 68, such as... Figure 3 As shown, multiple molds 68 are connected end-to-end and rotated on a planar circular track on a rotary frame 69, driven as a whole by a rotary chain, which is connected to a drive motor. The mixer 67 is a six-station rotary mixing and pulping machine structure, with six mixing tanks fixed around a circular rotating platform, evenly distributed into six stations, namely, a cleaning station, a water adding station, a powder adding station, a glass fiber adding station, a mixing station, and a grouting station. The mixing tank at the grouting station is located directly above one of the molds on the rotary frame 69. The circular rotating platform is connected to a rotary motor drive, which can drive the six mixing tanks to rotate intermittently around the center. Each mixing tank is equipped with a slide valve on its bottom surface.
[0019] The water spray pipe 61 is connected to an external water pump, and the spray nozzle is located above the mixing tank of the cleaning station. The guide plate 64 is inclinedly set below the mixing tank of the cleaning station. The material distribution bin 56 is located between the neutralization and proportioning zone 5 and the mixing and pulping zone 6. The upper inlet is connected to the outlet of the quantitative conveyor 51, and the lower outlet is connected to the powder adding pipe 62. The lower outlet of the powder adding pipe 62 is located above the mixing tank of the powder adding station. The upper end of the water adding pipe 63 is connected to the process water tank 57, and the lower outlet is located above the mixing tank of the water adding station. The upper end of the glass fiber adding pipe 66 is connected to the outlet of the glass fiber tank 59, and the lower outlet is located above the mixing tank of the glass fiber adding station.
[0020] A through-type splash guard 65 is fixedly installed between the mixing tank at the grouting station and the mold. The shape and size of the through-section of the splash guard 65 are equal to the shape and size of the grout inlet of the mold. Since there is a certain distance between the bottom of the mixing tank at the grouting station and the grout inlet on the upper surface of the mold, the liquid gypsum slurry will splash when it falls due to gravity. Therefore, according to the shape and size of the grout inlet of the mold, a square or circular through-type splash guard 65 is installed between them. The bottom surface of the splash guard contacts the four sides of the grout inlet on the upper surface of the mold, and the splashing of gypsum slurry can be blocked by the inner wall of the splash guard.
[0021] Flow control valves are installed on the water spray pipe 61 and the water inlet pipe 63, and metering control valves are installed on the powder inlet pipe 62 and the fiberglass inlet pipe 66.
[0022] Example 1: Neutralization Feeding Process The gypsum powder in the silo 1 is transported to the elevator 3 via the first transverse conveyor 2, and then to the second transverse conveyor 4. After being screened by the screening machine 53 to remove trace amounts of large-particle impurities, it enters the transfer silo 52. The storage capacity of the transfer silo can directly guarantee a certain amount of production supply. When the transfer silo 52 is full, the first transverse conveyor 2, the elevator 3, and the second transverse conveyor 4 are automatically controlled to temporarily stop operating. When the storage in the transfer silo 52 is low, the external feeding equipment is automatically controlled to supply material. The transfer silo 52 stably supplies material to the left inlet of the quantitative conveyor 51, while the solid additives are proportionally supplied to the right inlet of the quantitative conveyor 51. The two solid raw materials continue to be transversely conveyed in the spiral quantitative conveyor and mixed evenly. Then, they fall quantitatively into the distribution silo 56 through the outlet. The capacity of the distribution silo 56 is equal to the casting requirement for producing 20-30 individual gypsum profiles.
[0023] The liquid additive tank 58 and the external water pipe simultaneously add liquid materials to the process water tank 57 in proportion, and the liquid additive dissolves and is uniformly mixed in the process water tank 57.
[0024] Example 2, Mixing and Pulping Process The mixer 67 drives six mixing drums to rotate intermittently, with the rotation interval set according to the curing time of the gypsum raw material formula. When one of the mixing drums rotates to the cleaning station and then stops intermittently, the water spray pipe 61 sprays water into its interior to clean the inner wall and prevent residual gypsum slurry from solidifying on the inner wall. At this time, the slide valve at the bottom of the mixing drum is open, and the cleaning water is collected in a wastewater tank at a specific location through the guide plate 64 to prevent it from flowing around. Then, when the mixing drum rotates to the water adding station and stops, the slide valve closes, and the process water tank 57 injects a metered amount of process water into its interior. Then, the mixing drum rotates sequentially to the powder adding station and the glass fiber adding station, where metered amounts of gypsum powder and glass fiber are added respectively. When the mixing tank rotates to the mixing station, the gypsum slurry is further and thoroughly mixed. Finally, when the mixing tank rotates to the grouting station and comes to a stop, the slide valve opens, and the gypsum slurry in the tank passes through the splash guard 65 and falls into the lower mold by gravity. After the slurry is poured, the mixing tank rotates to the cleaning station again to continue the next round. The intermittent movement rhythm of the six mixing tanks is consistent, and they pass through the six stations in sequence. Each time the mixing tank grouts, the mold on the rotary frame 69 is driven forward one station, and the next empty mold moves to the bottom of the grouting station to receive the slurry. Overall, the neutralization and slurry preparation of phosphogypsum is achieved.
[0025] The flow meter, metering control valve, and metering valve 55 in this solution are all known technologies in terms of structure and control, and respectively realize the quantitative supply of liquid and solid materials; the slide valve is a known technology, and realizes automatic control of opening and closing the valve; the transverse conveyor, quantitative conveyor, elevator, fiberglass bin, mixer 67, rotary frame 69 and rotary chain drive series mold mechanism and control method are known technologies, and the structure of the mold 68 is determined according to the shape of the gypsum building material to be cast.
[0026] This solution has a clever structure and innovates the neutralization and pulping matching scheme for the resource utilization of phosphogypsum. The addition of alkaline additives to neutralize the acidity only needs to be added during the casting process, which greatly simplifies the technical route of resource utilization, streamlines the production process, reduces costs, improves the economic efficiency of phosphogypsum resource utilization, and realizes the automation of the phosphogypsum pulping application process.
Claims
1. A neutralization pulping device for phosphogypsum resource utilization, characterized in that, The system includes a silo (1), a first transverse conveyor (2), an elevator (3), a second transverse conveyor (4), a neutralization and proportioning zone (5), a mixing and pulping zone (6), a ground surface (7), and a workshop (8). The silo (1) is a hollow structure with a cylindrical upper part and a conical lower part, with an inlet at the top and an outlet and valve at the bottom. The silo (1), the first transverse conveyor (2), and the elevator (3) are located on the ground surface outside the workshop (8). The inlet of the first transverse conveyor (2) is connected to the silo (1). The discharge port and valves are as follows: the discharge port of the first transverse conveyor (2) is connected to the inlet of the bottom of the elevator (3); the elevator (3) is a vertical elevator, its inlet is set below the ground plane, and its discharge port is higher than the top of the workshop (8); the second transverse conveyor (4) is set on the roof of the workshop (8), and the inlet of the second transverse conveyor (4) is connected to the discharge port of the elevator (3); the workshop (8) is divided into two layers, the upper layer is the neutralization and proportioning zone (5), and the lower layer is the mixing and pulping zone (6).
2. The neutralization pulping device for phosphogypsum resource utilization according to claim 1, characterized in that, The neutralization and proportioning zone (5) includes: a quantitative conveyor (51), a transfer chamber (52), a screening machine (53), a solid additive chamber (54), a metering valve (55), a distribution chamber (56), a process water chamber (57), a liquid additive chamber (58), and a fiberglass chamber (59). The quantitative conveyor (51) is a horizontal conveying structure, located on the bottom surface of the upper layer. The upper part of the quantitative conveyor (51) has two feed inlets, one on the left and one on the right. The transfer chamber (52) is located above the left feed inlet. The screening machine (53) is located above the transfer chamber (52). The feed inlet of the transfer chamber (52) is connected to the discharge port of the screening machine (53), and the discharge port is connected to the quantitative conveyor. The left feed inlet of the conveyor (51) and the feed inlet of the screening machine (53) extend out of the top of the workshop and connect to the discharge outlet of the second transverse conveyor (4); the solid additive bin (54) is located above the right feed inlet of the quantitative conveyor (51), and the discharge outlet of the solid additive bin (54) and the right feed inlet of the quantitative conveyor (51) are connected by a metering valve (55); the process water bin (57) and the glass fiber bin (59) are located on the right side of the quantitative conveyor (51), and the liquid additive bin (58) is located on the upper part of the process water bin (57). The two are connected by a set of flow control valves and pipelines, and the process water bin (57) is also connected to an external water supply pipe through another set of flow control valves and pipelines.
3. The neutralization pulping device for phosphogypsum resource utilization according to claim 2, characterized in that, The mixing and pulping zone (6) includes: a water spray pipe (61), a powder adding pipe (62), a water adding pipe (63), a guide plate (64), a splash guard (65), a glass fiber adding pipe (66), a mixer (67), a mold (68), and a rotary frame (69). The rotary frame (69) is the rotary motion track for the mold (68). Multiple molds (68) are connected end-to-end by chains and are rotaryly installed on a planar circular track on the rotary frame (69). The chains are connected to a drive motor. The mixer (67) is a rotary mixing pulping machine structure. Six mixing tanks are fixed around a circular rotating platform and are evenly distributed into six workstations, which are, in order, a cleaning workstation, a water adding workstation, a powder adding workstation, a glass fiber adding workstation, a mixing workstation, and a grouting workstation. The mixing tank of the grouting workstation is located directly above one of the molds (68) on the rotary frame (69). A circular rotating platform is connected to a rotating motor drive, which can drive six mixing tanks to rotate intermittently around the center. Each mixing tank has a slide valve on its bottom surface. The water spray pipe (61) is connected to a water pump, and the water spray nozzle is located above the mixing tank at the cleaning station. The guide plate (64) is inclined and set below the mixing tank at the cleaning station. The material distribution bin (56) is located between the neutralization and proportioning zone (5) and the mixing and pulping zone (6). The upper inlet is connected to the outlet of the quantitative conveyor (51), and the lower outlet is connected to the powder adding pipe (62). The lower outlet of the powder adding pipe (62) is located above the mixing tank at the powder adding station. The upper end of the water adding pipe (63) is connected to the process water tank (57), and the lower outlet is located above the mixing tank at the water adding station. The upper end of the glass fiber adding pipe (66) is connected to the outlet of the glass fiber tank (59), and the lower outlet is located above the mixing tank at the glass fiber adding station.
4. The neutralization pulping device for phosphogypsum resource utilization according to claim 2, characterized in that, The quantitative conveyor (51) adopts a propeller conveying structure.
5. A neutralization and pulping device for the resource utilization of phosphogypsum according to claim 3, characterized in that, A splash guard (65) is installed between the mixing tank and the mold (68) at the grouting station.
6. The neutralization pulping device for phosphogypsum resource utilization according to claim 3, characterized in that, A flow control valve is installed on the water spray pipe (61) and the water supply pipe (63), and a metering control valve is installed on the powder supply pipe (62) and the fiberglass supply pipe (66).