Semi-dry method continuous static pressure ardealite hollow block production device and method

Abstract

The invention relates to the technical field of ardealite hollow block production, and discloses a semi-dry method continuous static pressure ardealite hollow block production device, which comprises a pressure forming structure configured to have an adhesion-free extrusion space, and the extrusion space can continuously vibrate for beta-semi-hydrated ardealite blanking; and the double-face extrusion structure is configured to be provided with an extrusion line extending in the direction penetrating through the extrusion space, and the starting point and the ending point of the extrusion line mutually form relative extrusion force towards the extrusion space. The precise regulating agent for the hydration rate of the ardealite can delay and accelerate the hydration hardening rate of the beta-semi-hydrated ardealite, and the viscosity of the beta-semi-hydrated ardealite can be adjusted while the water is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of phosphogypsum hollow building block production, and in particular to a semi-dry process continuous static pressure phosphogypsum hollow building block production device and a method thereof. Background Art

[0002] Phosphogypsum brickwork is a new type of lightweight wall material with the advantages of environmental protection and energy saving, high strength, earthquake resistance, heat preservation, sound insulation, fire resistance, moisture resistance and easy use and installation. It is particularly suitable for high-rise and large-span new urban and rural houses as interior wall partition materials. It is a new type of wall material that has been vigorously developed and promoted in the field of national housing and urban and rural construction for many years.

[0003] The new lightweight wall material of phosphogypsum brick is usually produced by mechanized casting and molding (usually referred to as "wet production"). In the mechanized casting and molding production process, in order to stir evenly and facilitate casting and molding, the amount of water added is usually more than 70% of the amount of modified phosphogypsum powder. Therefore, after demoulding, the moisture content of the phosphogypsum brick also reaches about 70%. At this time, the phosphogypsum powder needs to be opened for drying or drying. At this time, about 50% of the water will be consumed to obtain phosphogypsum brick products with performance indicators that meet relevant standards. Therefore, energy consumption and production costs will be increased. In addition, in the mechanized casting and demoulding process, after the stirred phosphogypsum powder slurry is poured into the mold cavity, it needs to be left to stand in the mold cavity for hydration until it is initially set to form a certain strength before it can be lifted and demoulded. Therefore, the production of phosphogypsum bricks produced by mechanized casting and molding takes a long time, and the production efficiency and output are low.

[0004] After hydration, phosphogypsum powder will form β-hemihydrate phosphogypsum. The hydration product of β-hemihydrate phosphogypsum is a cubic crystal structure, which has insufficient structural tightness and poor stability. As a result, when β-hemihydrate phosphogypsum is used as a raw material to prepare phosphogypsum bricks, there are still the following defects:

[0005] ① In the process of phosphogypsum brickwork, since the phosphogypsum in the hollow phosphogypsum blocks is not completely hydrated in a short time, a large amount of free water is adsorbed on the surface of the hollow phosphogypsum blocks, resulting in the strong viscosity of the hollow phosphogypsum blocks themselves. Therefore, it is easy to have a sticky film phenomenon. When the hollow phosphogypsum blocks are extruded in the mold, the hollow phosphogypsum blocks are easy to bond with the mold, making it difficult to demold the hollow phosphogypsum blocks. Even if the hollow phosphogypsum blocks can be demolded, part of the surface of the hollow phosphogypsum blocks will be bonded to the mold, resulting in poor surface quality of the hollow phosphogypsum blocks.

[0006] ② Since the hydration and hardening time of β-hemihydrate phosphogypsum is relatively long, it takes a certain amount of time for hydration and hardening to have a certain strength for demolding, which makes it difficult to use the pressing method for continuous molding. Therefore, in order to ensure the stable operation of the semi-dry continuous production line, a precise controller of the hydration rate of phosphogypsum has been developed, which can delay and accelerate the hydration and hardening rate of β-hemihydrate phosphogypsum. This achieves the goal of reducing water while adjusting the viscosity of β-hemihydrate phosphogypsum, which has become a technical problem that technical personnel in this field urgently need to overcome. Summary of the invention

[0007] The present invention aims to provide a semi-dry continuous static pressure phosphogypsum hollow block production device and a control method thereof, which is a precise controller of the hydration rate of phosphogypsum that can delay and accelerate the hydration and hardening rate of β-hemihydrate phosphogypsum, thereby achieving the goal of reducing water while adjusting the viscosity of β-hemihydrate phosphogypsum, which has become a technical problem that technicians in this field urgently need to overcome.

[0008] In order to achieve the above object, the present invention adopts the following technical scheme:

[0009] 1) Semi-dry continuous static pressing phosphogypsum hollow block production device, including:

[0010] The pressure forming structure is configured to have a non-sticking extrusion space, the extrusion space can continuously vibrate to feed β-hemihydrate phosphogypsum, the raw materials of the β-hemihydrate phosphogypsum include phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating aid and water, the phosphogypsum powder is used to delay the hydration reaction time of the dihydrate phosphogypsum powder and allow both to have sufficient time to be fully mixed with water, the dihydrate phosphogypsum powder is used to accelerate the hydration speed of the phosphogypsum powder, the hydration regulating aid is used to initially separate water molecules from the phosphogypsum powder and the dihydrate phosphogypsum powder, and wrap several water molecules in the water to form a granular water reservoir, and during the hydration process, part of the granular water reservoir is dispersed in the phosphogypsum powder environment and adheres to the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder;

[0011] The double-sided extrusion structure is configured to have an extrusion line extending along a direction passing through the extrusion space, and the starting point and the end point of the extrusion line form relative extrusion forces toward the extrusion space.

[0012] The determining factor of the strength development of phosphogypsum brickwork in the present invention lies in the hydration of β-hemihydrate phosphogypsum. The hydration of β-hemihydrate phosphogypsum must meet both the requirements of rapid hydration and the strength development required to achieve the hardening of phosphogypsum brickwork. Therefore, the hydration control of β-hemihydrate phosphogypsum is very critical.

[0013] Therefore, the β-hemihydrate phosphogypsum in the phosphogypsum brickwork of the present invention adopts phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating auxiliary agent and water. The phosphogypsum powder and the dihydrate phosphogypsum powder react with water to form β-hemihydrate phosphogypsum. During this process, the phosphogypsum powder and the dihydrate phosphogypsum powder interact with each other. Since the dihydrate phosphogypsum powder is the waste crushed material generated when producing phosphogypsum brickwork, the dihydrate phosphogypsum powder is added to the phosphogypsum powder, which can not only ensure that the flexural and compressive strengths of the phosphogypsum hollow blocks are much higher than the industry standard requirements, but also realize the resource utilization of waste bricks generated during the production site, factory area and product transportation and construction and use, which saves raw material costs and is environmentally friendly.

[0014] The dihydrate phosphogypsum powder (CaSO4·2H2O crystals) has a high solubility. Therefore, it dissolves under the action of water. After dissolution, it combines with the dihydrate phosphogypsum crystal nuclei formed by the hydration of the phosphogypsum powder to promote the growth and development of the dihydrate phosphogypsum crystal nuclei formed again, thereby accelerating the hydration rate of the phosphogypsum powder.

[0015] However, since there is a small amount of insoluble substances in the phosphogypsum powder (there are soluble impurities such as phosphorus and fluorine in the phosphogypsum powder itself, when it reacts with water, the soluble phosphorus, fluorine and Ca 2+ When dissolved in water, a chemical reaction occurs between the three to generate insoluble substances), and a small amount of insoluble substances will cover the surface of dihydrate phosphogypsum powder, thereby hindering the combination of dihydrate phosphogypsum powder and water, thereby delaying the hydration time of dihydrate phosphogypsum powder, making the dihydrate phosphogypsum powder act on the hydration speed of phosphogypsum powder, delaying the hydration time of phosphogypsum powder, ensuring that dihydrate phosphogypsum powder and phosphogypsum powder have sufficient time to mix quickly and evenly, and at the same time, shortening the time for phosphogypsum powder to produce viscosity after hydration, reducing the adhesion amount of produced β-hemihydrate phosphogypsum.

[0016] In addition, when the hydration regulating auxiliary agent of the present invention is in the initial state, water is separated from the phosphogypsum powder and the dihydrate phosphogypsum powder, which can delay the hydration phenomenon of the phosphogypsum powder and the dihydrate phosphogypsum powder. At the same time, the water molecules in the water are wrapped in combination with the hydration regulating auxiliary agent to form a granular water reservoir. Several granular water reservoirs are attached to the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder in the phosphogypsum powder environment, thereby ensuring that the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder is evenly distributed with the water addition amount that can hydrate both, thereby effectively reducing the amount of water addition.

[0017] At the same time, the β-hemihydrate phosphogypsum is continuously fed into the extrusion space. During the feeding process, the extrusion space continuously vibrates, so that the β-hemihydrate phosphogypsum is evenly laid in the extrusion space during the vibration process. Since the extrusion space is sticky-free, the β-hemihydrate phosphogypsum will not stick during the feeding process. At the same time, the extrusion line along the direction of the extrusion space moves relative to each other through the double-sided extrusion structure, so that the starting point and the end point of the extrusion line form a double-sided extrusion of the β-hemihydrate phosphogypsum in the extrusion space. During the extrusion of the β-hemihydrate phosphogypsum, the granular water reservoir attached to the surface of the incompletely hydrated phosphogypsum powder is squeezed and broken, so that the water in the granular water reservoir bursts out and is fully hydrated with the incompletely hydrated phosphogypsum powder, releasing a certain amount of heat during the hydration process, and while releasing the heat, the β-hemihydrate phosphogypsum is promoted to form and harden quickly. Therefore, the present invention combines phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating auxiliary agent and water of β-hemihydrate phosphogypsum raw materials to realize a precise regulator of phosphogypsum hydration rate that delays and accelerates the hydration and hardening rate of β-hemihydrate phosphogypsum, thereby achieving the goal of reducing water while adjusting the viscosity of β-hemihydrate phosphogypsum.

[0018] The hydration characteristics of phosphogypsum powder and dihydrate gypsum, and the dispersibility of hydration regulating additives are then utilized. The two complement each other to delay the time of hydration and shorten the time for the phosphogypsum powder to produce viscosity after hydration. Therefore, according to the addition amount of phosphogypsum powder, dihydrate gypsum and hydration regulating additives, sticky-free extrusion space, vibrating feeding and double-sided extrusion, the viscosity of β-hemihydrate phosphogypsum can be adjusted in real time, thereby shortening the hydration and hardening time of β-hemihydrate phosphogypsum, and continuous molding can be carried out by pressing, thereby ensuring the stable operation of the semi-dry continuous production line.

[0019] 2) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 1), wherein:

[0020] The raw materials of the β-hemihydrate phosphogypsum also include polypropylene staple fibers, wherein the weight component of the phosphogypsum powder is 100 parts, the weight component of the dihydrate phosphogypsum powder is 8-10 parts, the weight component of the polypropylene staple fibers is 0.05-0.1 parts, the weight component of the hydration regulating auxiliary agent is 0.1-0.2 parts, and the weight component of the water is 28-32 parts.

[0021] The weight component of the dihydrate phosphogypsum powder in the present invention accounts for 8%-10% of the weight component of the phosphogypsum powder. The use of the dihydrate phosphogypsum powder can fully promote the growth and development of crystal nuclei during the hydration process of the phosphogypsum powder; the weight component of the hydration regulating auxiliary agent accounts for 0.1%-0.2% of the weight component of the phosphogypsum powder. Compared with the prior art in which a large amount of modifiers are added, the present invention adopts the hydration regulating auxiliary agent to interact with the dihydrate phosphogypsum powder, and the water in the hydration regulating auxiliary agent is used to form several granular reservoirs to hydrate the dihydrate phosphogypsum powder. The two act on the phosphogypsum powder together, which not only reduces the addition amount of the hydration regulating auxiliary agent, but also ensures the utilization rate and filling rate of the phosphogypsum powder in the beta-hemihydrate phosphogypsum generated by the dihydrate phosphogypsum powder and the hydration regulating auxiliary agent, and at the same time reduces the cost of preparing the beta-hemihydrate phosphogypsum into phosphogypsum bricks.

[0022] On this basis, the raw material of the β-hemihydrate phosphogypsum of the present invention further includes short polypropylene fibers, and the short polypropylene fibers are evenly laid in the hydrated β-hemihydrate phosphogypsum. During the double-sided extrusion process of the β-hemihydrate phosphogypsum molding process, the pulling of the short polypropylene fibers in the β-hemihydrate phosphogypsum forms the initial strength of the phosphogypsum brickwork, so that the short polypropylene fibers can strengthen the strength of the phosphogypsum brickwork, so that the breaking load of the phosphogypsum brickwork can generally reach about 10000N (the industry 69 standard requires more than 2000N), and the compressive strength can generally reach more than 5MPa. Even if the product is loaded and transported immediately after it comes off the line, it will not be damaged due to the bumps during transportation. The problem of damage to the original phosphogypsum brickwork during transportation is fundamentally solved.

[0023] 3) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 1), wherein:

[0024] The hydration control auxiliary agent includes a dispersant and a resin, and the dispersant and the resin are prepared in a weight ratio of 1:(2-3).

[0025] The resin in the present invention has the function of wrapping several water molecules in water to form granular water, the dispersant has the function of dispersing water in phosphogypsum powder and dihydrate phosphogypsum powder, and preventing water and phosphogypsum powder or dihydrate phosphogypsum powder from aggregating and reacting with each other, and at the same time, the dispersant is combined with the resin to wrap water molecules to form a granular water reservoir, and when the granular water reservoir is in a static state, the granular water reservoir will not be hydrated with the phosphogypsum powder or dihydrate phosphogypsum powder, and the granular water reservoir can be evenly dispersed under the action of the dispersant.

[0026] In addition, the dispersant and resin designed in the present invention are formulated in a weight component ratio of 1: (2-3). In the market, the price of the resin is lower than that of the dispersant. Therefore, compared with the modifier in the prior art, the present invention reduces the addition of the modifier, thereby reducing the cost of preparing β-hemihydrate phosphogypsum into phosphogypsum bricks; in addition, the weight component of the resin accounts for 2-3 times that of the dispersant. Therefore, the water absorption rate of the resin is used to greatly increase the water storage capacity of the granular water reservoir, and the dispersant is used to reduce the viscosity and viscosity of the resin, thereby improving the flowability of the resin, so that the granular water reservoir formed by the resin-shaped water molecules can be evenly distributed on the surface of the phosphogypsum powder and the dihydrate phosphogypsum powder, which can improve the uniformity of hydration. At the same time, part of the granular water reservoir can remain attached to the surface of the phosphogypsum powder, so that the hydration reaction of the β-hemihydrate phosphogypsum is thorough during the extrusion process.

[0027] 4) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 1), wherein:

[0028] The pressurized molding structure includes a molding frame and a vibration plate arranged in sequence from top to bottom, with a certain distance between the molding frame and the vibration plate, and a plurality of mold cavities penetrating the molding frame along the axial direction are evenly distributed in the molding frame, and all the mold cavities together form an extrusion space, and a mold core in a vertical state is provided in each mold cavity along its axial direction, and the mold core is suspended in the mold cavity, and the bottoms of all the mold cores are fixed on the vibration plate, and a vibrator is installed on the vibration plate, and a plurality of through holes penetrating the vibration plate along the axial direction are evenly distributed in the vibration plate, and the positions of the through holes correspond one by one to the positions of the mold cavities, and the starting point of the extrusion line in the double-sided extrusion structure is extruded toward the mold cavity, and the ending point of the extrusion line passes through the through holes and is extruded toward the mold cavity.

[0029] When the hydrated beta-hemihydrate phosphogypsum of the present invention is discharged into the mold cavity in the molding frame, the vibrator drives the vibration plate to vibrate, and the vibration plate drives the mold core in the mold cavity to vibrate, and the mold core drives the beta-hemihydrate phosphogypsum to vibrate in the mold cavity, so that the beta-hemihydrate phosphogypsum is evenly distributed in the mold cavity, so that the granular water reservoir attached to the incompletely hydrated phosphogypsum powder in the beta-hemihydrate phosphogypsum can be relatively extruded toward all the mold cavities at the starting point and the end point of the extrusion line in the double-sided extrusion structure, and the granular water reservoir can be instantly broken to promote the rapid hydration of the phosphogypsum powder, so that the beta-hemihydrate phosphogypsum is completely hydrated, and a certain amount of heat can be released to promote the rapid hardening of the beta-hemihydrate phosphogypsum, thereby shortening the molding cycle. Compared with domestic and foreign wet production and domestic and foreign semi-dry production (non-continuous production), the molding cycle of the present invention is controlled between 25-30S, which greatly shortens the molding cycle and improves production efficiency.

[0030] 5) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 4), wherein:

[0031] The molding frame is an integrated structure, and the inner surfaces of all mold cavities in the molding frame are provided with a plurality of anti-sticking plates, and there is an embedded steel located at the inner corner of the mold cavity between adjacent anti-sticking plates, and there is a gap between the embedded steel and the anti-sticking plate.

[0032] In the prior art, when the phosphogypsum hollow blocks are extruded and formed in a mold, the phosphogypsum hollow blocks are easily bonded to the mold, making it difficult to demold the phosphogypsum hollow blocks. Even if the phosphogypsum hollow blocks can be demolded, part of the surface of the phosphogypsum hollow blocks will be bonded to the mold, resulting in poor surface quality of the phosphogypsum hollow blocks.

[0033] Therefore, the present invention arranges several anti-sticking plates on the inner surface of the mold cavity to avoid the incompletely hydrated β-hemihydrate phosphogypsum being discharged during the extrusion process. The sticky lumps produced by the hydration of the phosphogypsum powder and the granular water reservoir in the incompletely hydrated β-hemihydrate phosphogypsum will not adhere to the anti-sticking plates, so that the heat generated during the hydration process of the phosphogypsum powder promotes the rapid hardening of the β-hemihydrate phosphogypsum. After hardening, the extruded phosphogypsum hollow blocks will not adhere to the anti-sticking plates, which is convenient for the phosphogypsum hollow blocks to be quickly demolded. At the same time, the embedded steel between adjacent anti-sticking plates can reduce the damage to the corner of the mold cavity caused by the extrusion force applied during the extrusion process, thereby reducing the defective rate of the extruded phosphogypsum hollow blocks and improving the service life of the mold cavity.

[0034] In addition, the gaps between several adjacent anti-sticking plates in the present invention have two functions: the first function is to provide space for the thermal expansion and contraction of the anti-sticking plates, so that the expansion of the anti-sticking plates due to the heat generated by the hydration of the phosphogypsum powder will not squeeze the adjacent embedded steel, thereby avoiding the bulging of the surrounding side of the embedded steel after being subjected to force, thereby affecting the service life of the mold cavity.

[0035] The second function is to provide a thermal insulation environment in the mold cavity. When the incompletely hydrated phosphogypsum powder in the β-hemihydrate phosphogypsum is vibrated and fed into the mold cavity, the incompletely hydrated phosphogypsum powder accumulates in the gap between the anti-sticking plate and the embedded plate. The heat generated during the hydration of the phosphogypsum powder in the gap will be released into the mold cavity, thereby ensuring that the mold cavity is in a relatively stable temperature environment, thereby accelerating and deepening the hydration reaction of the phosphogypsum powder, and quickly obtaining fully final-set phosphogypsum hollow blocks.

[0036] 6) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 4), wherein:

[0037] The double-sided extrusion structure includes an upper mold and a lower mold, wherein the upper mold is located at the starting point of the extrusion line, and the lower mold is located at the end point of the extrusion line. The upper mold and the lower mold move relative to each other toward the mold cavity, wherein the lower mold extends toward the mold cavity through the through hole and maintains a relative position, and the upper mold moves away from the mold frame and toward the mold cavity in the mold frame.

[0038] In the double-sided extrusion structure of the present invention, the upper mold and the lower mold serve as the starting point and the end point of the extrusion line extending in the direction through the extrusion space, respectively. At this time, before use, the lower mold extends into the mold cavity through the perforation of the vibration plate to maintain a relative position, thereby realizing a closed state of the bottom of the mold cavity. When the β-hemihydrate phosphogypsum is discharged, it will first accumulate on the upper surface of the lower mold. At the same time, during the vibration process of the vibration plate, its lower mold and mold core vibrate synchronously, so that the β-hemihydrate phosphogypsum can fall evenly and accumulate on the lower mold within the effective time. Then, the upper mold and the lower mold move relative to each other, the lower mold drives the β-hemihydrate phosphogypsum to move toward the upper mold, and the upper mold moves toward the mold cavity, thereby realizing rapid double-sided pressurization of the β-hemihydrate phosphogypsum, which can ensure high molding quality and improve production efficiency.

[0039] 7) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 6), wherein:

[0040] The upper mold part includes an upper pressure head, and the lower mold part includes a lower pressure head. Openings for the mold core to pass through are opened in the middle of the upper pressure head and the lower pressure head. Press plates are respectively installed on the opposite surfaces of the upper pressure head and the lower pressure head, and the press plates are made of anti-sticking material.

[0041] When the present invention is used, the upper pressure head first presses downward toward the mold cavity with a pressure of 180 tons per second (18 MPa), stops moving when the path reaches 50 mm, and then presses upward toward the mold cavity with a pressure of 230 tons per second (23 MPa) until the size guarantees the set height, and then presses for 3 seconds (static pressure for 3 seconds) to match the mold core to form a phosphogypsum hollow block, the upper pressure head releases pressure, and the lower pressure head continues to push the phosphogypsum hollow block upward. The total duration of this process is 25S-30S. According to performance testing, the average duration is 26.2S, and it can work uninterruptedly, quickly pressurize on both sides, and can ensure high molding quality and improve production efficiency.

[0042] In addition, the pressure plate in the present invention is made of a non-adhesive material. Therefore, during the extrusion process of the upper pressure head and the lower pressure head, the pressure plate separates the upper pressure head or the lower pressure head from the β-hemihydrate phosphogypsum, avoiding the bonding phenomenon of the β-hemihydrate phosphogypsum during the extrusion hydration process, and sticking to the upper pressure head and the lower pressure head, thereby facilitating the demoulding of the hollow phosphogypsum bricks from the mold cavity and ensuring the surface quality of the hollow phosphogypsum blocks.

[0043] 8) The semi-dry continuous static pressing phosphogypsum hollow block production device according to 7), wherein:

[0044] The upper mold component includes an upper mold base, and a plurality of upper mold columns are provided on the end surface of the upper mold base facing the mold cavity, the positions of the upper mold columns correspond to the positions of the mold cavity one by one, and the end surface of each upper mold column facing the mold cavity is fixedly connected to the upper pressure head; the lower mold component includes a lower mold base, and a plurality of lower mold columns are provided under the end surface of the lower mold base facing the mold cavity, the positions of the lower mold columns correspond to the positions of the mold cavity one by one, and the end surface of each lower mold column facing the mold cavity is fixedly connected to the lower pressure head.

[0045] The upper die base used in the present invention supports a plurality of upper die columns, each of which corresponds to a die cavity and can extend into the die cavity, thereby driving an upper pressure head to be located in the die cavity; and the lower die base used in the present invention supports a plurality of lower die columns, each of which corresponds to a die cavity and can extend into the die cavity, thereby driving a lower pressure head to be located in the die cavity, thereby ensuring that the upper pressure head and the lower pressure head perform double-sided extrusion on β-hemihydrate phosphogypsum.

[0046] 9) The semi-dry continuous static pressure phosphogypsum hollow block production device according to 7), wherein:

[0047] The anti-sticking plate and the pressing plate are both made of polytetrafluoroethylene.

[0048] The anti-sticking plate and the pressing plate are made of polytetrafluoroethylene. Polytetrafluoroethylene has the characteristics of minimum surface tension, non-adhesion to any substance, and low friction coefficient. Therefore, the mold cavity, the upper pressure head and the lower pressure head have the characteristics of non-adhesion and friction resistance, thereby extending the service life of the mold cavity, the upper pressure head and the lower pressure head, and reducing the maintenance frequency and maintenance cost of the pressurized molding structure and the double-sided extrusion structure.

[0049] 10) A semi-dry continuous static pressing phosphogypsum hollow block production method, which is applied to the semi-dry continuous static pressing phosphogypsum hollow block production device in 1) to 9) above, comprising the following steps:

[0050] Step 1, lower mold preparation state: several lower mold columns in the lower mold pass through the vibration plate together, and then all the lower mold columns extend into their corresponding mold cavities and remain motionless;

[0051] Step 2: Vibration distribution: When the β-hemihydrate phosphogypsum is poured into the mold cavity, the β-hemihydrate phosphogypsum is supported by the lower pressure head of the lower mold column. At this time, the vibrator on the vibration plate receives a signal and starts to vibrate, driving all the mold cores on the vibration plate to shake, so that the β-hemihydrate phosphogypsum can fall evenly into the mold cavity within the effective time;

[0052] Step 3, double-sided extrusion: The upper pressure head presses downward toward the mold cavity at a pressure of 180 tons per second and 18 MPa, and stops moving when the travel distance reaches 50 mm. Then the lower pressure head presses upward toward the mold cavity at a pressure of 230 tons per second and 23 MPa until the size guarantees the set height, and then presses for 3 seconds without moving to match the mold core to form a phosphogypsum hollow block;

[0053] Step 4: Push out of the mold: the upper pressure head releases the pressure, and the lower pressure head continues to push the phosphogypsum hollow blocks upward.

[0054] Compared with the prior art, the present invention also has the following technical effects:

[0055] 1. During the initial trial operation of the present invention, it was found that the hydration of phosphogypsum was incomplete and the water content of the phosphogypsum hollow blocks was high. In order to complete the final setting of the gypsum blocks as soon as possible, after the pressed blocks were demoulded, the granular water reservoir and the incompletely hydrated phosphogypsum powder were completely hydrated during the extrusion process. The β-hemihydrate phosphogypsum generated during the hydration process released a large amount of heat, and this part of the heat source was used for the phosphogypsum hollow blocks to accelerate and deepen the hydration reaction of the phosphogypsum powder, so as to obtain completely final set phosphogypsum hollow blocks. According to the analysis of the three phases of gypsum, the hydration reaction completion rate was more than 95%, and the water content was generally about 20%.

[0056] 2. In order to improve the product quality and production efficiency of phosphogypsum hollow blocks produced by semi-dry continuous static pressure molding, a double-sided pressurized special phosphogypsum hollow block semi-dry high-speed molding method has been developed. It uses double-sided pressurization and can form 0.144 cubic meters of blocks every 25 seconds, which can ensure the high-speed molding quality of the blocks.

[0057] 3. We independently developed a double-sided molding production system for phosphogypsum hollow blocks for molding and demoulding. A 0.144m block can be molded every 25-30 seconds, realizing continuous mechanized production of blocks and greatly improving the production efficiency and product qualification rate of blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 The present invention is a schematic diagram of the structure of a semi-dry continuous statically pressed phosphogypsum hollow block production device.

[0059] Figure 2 The present invention is a schematic diagram of the structure of the mold cavity in the semi-dry continuous static pressing phosphogypsum hollow block production device. DETAILED DESCRIPTION

[0060] The following is further described in detail through specific implementation methods:

[0061] The figure marks in the drawings of the specification include: forming frame 1, vibration plate 2, lower mold base 3, upper mold base 4, upper mold column 5, pressure plate 6, mold core 7, mold cavity 8, spring column 9, lower mold column 10, limit plate 11, mounting strip 12, anti-sticking plate 13, embedded steel 14.

[0062] Reference will now be made in detail to embodiments disclosed herein, examples of which are described herein and illustrated in the accompanying drawings. Although the present disclosure will be described in conjunction with embodiments and / or examples, they do not limit the present disclosure to these embodiments and / or examples. On the contrary, the present disclosure covers alternatives, modifications and equivalents.

[0063] This embodiment sees Figure 1 As shown, a semi-dry continuous statically pressed phosphogypsum hollow block production device comprises a pressurized molding structure and a double-sided extrusion structure matching the pressurized molding structure, wherein the pressurized molding structure is configured to have an extrusion space that is free of adhesion, and the double-sided extrusion structure is configured to have an extrusion line extending in a direction passing through the extrusion space, and the starting point and the end point of the extrusion line form relative extrusion forces toward the extrusion space.

[0064] In addition, the extrusion space can continuously vibrate to feed β-hemihydrate phosphogypsum. The raw materials of β-hemihydrate phosphogypsum include phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating aid and water. The phosphogypsum powder is used to delay the hydration reaction time of dihydrate phosphogypsum powder and allow both to have sufficient time to be fully mixed with water. The dihydrate phosphogypsum powder is used to accelerate the hydration rate of the phosphogypsum powder. The hydration regulating aid is used to initially separate water molecules from the phosphogypsum powder and dihydrate phosphogypsum powder, and wrap several water molecules in the water to form a granular water reservoir. During the hydration process, part of the granular water reservoir is dispersed in the phosphogypsum powder environment and adheres to the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder.

[0065] The determining factor of the strength development of phosphogypsum brickwork in the present invention lies in the hydration of β-hemihydrate phosphogypsum. The hydration of β-hemihydrate phosphogypsum must meet both the requirements of rapid hydration and the strength development required to achieve the hardening of phosphogypsum brickwork. Therefore, the hydration control of β-hemihydrate phosphogypsum is very critical.

[0066] Therefore, the β-hemihydrate phosphogypsum in the phosphogypsum brickwork of the present invention adopts phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating auxiliary agent and water. The phosphogypsum powder and the dihydrate phosphogypsum powder react with water to form β-hemihydrate phosphogypsum. During this process, the phosphogypsum powder and the dihydrate phosphogypsum powder interact with each other. Since the dihydrate phosphogypsum powder is the waste crushed material generated when producing phosphogypsum brickwork, the dihydrate phosphogypsum powder is added to the phosphogypsum powder, which can not only ensure that the flexural and compressive strengths of the phosphogypsum hollow blocks are much higher than the industry standard requirements, but also realize the resource utilization of waste bricks generated during the production site, factory area and product transportation and construction and use, which saves raw material costs and is environmentally friendly.

[0067] The dihydrate phosphogypsum powder (CaSO4·2H2O crystals) has a high solubility. Therefore, it dissolves under the action of water. After dissolution, it combines with the dihydrate phosphogypsum crystal nuclei formed by the hydration of the phosphogypsum powder to promote the growth and development of the dihydrate phosphogypsum crystal nuclei formed again, thereby accelerating the hydration rate of the phosphogypsum powder.

[0068] However, since the phosphogypsum powder contains a small amount of insoluble substances (the phosphogypsum powder itself contains soluble impurities such as phosphorus and fluorine. When it reacts with water to form a hydration reaction, the soluble phosphorus, fluorine and Ca2+ dissolve in the water, and a chemical reaction occurs between the three to form insoluble substances), and a small amount of insoluble substances will cover the surface of the dihydrate phosphogypsum powder. Therefore, the dihydrate phosphogypsum powder is hindered from combining with water, thereby delaying the hydration time of the dihydrate phosphogypsum powder, so that the dihydrate phosphogypsum powder acts on the hydration speed of the phosphogypsum powder, delaying the hydration time of the phosphogypsum powder, ensuring that the dihydrate phosphogypsum powder and the phosphogypsum powder have sufficient time to be quickly and evenly mixed. At the same time, the time for the phosphogypsum powder to produce viscosity after hydration is shortened, thereby reducing the adhesion amount of the produced β-hemihydrate phosphogypsum.

[0069] In addition, when the hydration regulating auxiliary agent of the present invention is in the initial state, water is separated from the phosphogypsum powder and the dihydrate phosphogypsum powder, which can delay the hydration phenomenon of the phosphogypsum powder and the dihydrate phosphogypsum powder. At the same time, the water molecules in the water are wrapped in combination with the hydration regulating auxiliary agent to form a granular water reservoir. Several granular water reservoirs are attached to the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder in the phosphogypsum powder environment, thereby ensuring that the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder is evenly distributed with the water addition amount that can hydrate both, thereby effectively reducing the amount of water addition.

[0070] At the same time, the β-hemihydrate phosphogypsum is continuously fed into the extrusion space. During the feeding process, the extrusion space continuously vibrates, so that the β-hemihydrate phosphogypsum is evenly laid in the extrusion space during the vibration process. Since the extrusion space is sticky-free, the β-hemihydrate phosphogypsum will not stick during the feeding process. At the same time, the extrusion line along the direction of the extrusion space moves relative to each other through the double-sided extrusion structure, so that the starting point and the end point of the extrusion line form a double-sided extrusion of the β-hemihydrate phosphogypsum in the extrusion space. During the extrusion of the β-hemihydrate phosphogypsum, the granular water reservoir attached to the surface of the incompletely hydrated phosphogypsum powder is squeezed and broken, so that the water in the granular water reservoir bursts out and is fully hydrated with the incompletely hydrated phosphogypsum powder, releasing a certain amount of heat during the hydration process, and while releasing the heat, the β-hemihydrate phosphogypsum is promoted to form and harden quickly. Therefore, the present invention combines phosphogypsum powder, dihydrate phosphogypsum powder, hydration regulating auxiliary agent and water of β-hemihydrate phosphogypsum raw materials to realize a precise regulator of phosphogypsum hydration rate that delays and accelerates the hydration and hardening rate of β-hemihydrate phosphogypsum, thereby achieving the goal of reducing water while adjusting the viscosity of β-hemihydrate phosphogypsum.

[0071] The hydration characteristics of phosphogypsum powder and dihydrate gypsum, and the dispersibility of hydration regulating additives are then utilized. The two complement each other to delay the time of hydration and shorten the time for the phosphogypsum powder to produce viscosity after hydration. Therefore, according to the addition amount of phosphogypsum powder, dihydrate gypsum and hydration regulating additives, sticky-free extrusion space, vibrating feeding and double-sided extrusion, the viscosity of β-hemihydrate phosphogypsum can be adjusted in real time, thereby shortening the hydration and hardening time of β-hemihydrate phosphogypsum, and continuous molding can be carried out by pressing, thereby ensuring the stable operation of the semi-dry continuous production line.

[0072] Among them, the raw materials of β-hemihydrate phosphogypsum also include polypropylene short fibers, wherein the weight component of phosphogypsum powder is 100 parts, the weight component of dihydrate phosphogypsum powder is 8-10 parts, the weight component of polypropylene short fibers is 0.05-0.1 parts, the weight component of hydration regulating additive is 0.1-0.2 parts and the weight component of water is 28-32 parts.

[0073] The weight component of the dihydrate phosphogypsum powder in the present invention accounts for 8%-10% of the weight component of the phosphogypsum powder. The use of the dihydrate phosphogypsum powder can fully promote the growth and development of crystal nuclei during the hydration process of the phosphogypsum powder; the weight component of the hydration regulating auxiliary agent accounts for 0.1%-0.2% of the weight component of the phosphogypsum powder. Compared with the prior art in which a large amount of modifiers are added, the present invention adopts the hydration regulating auxiliary agent to interact with the dihydrate phosphogypsum powder, and the water in the hydration regulating auxiliary agent is used to form several granular reservoirs to hydrate the dihydrate phosphogypsum powder. The two act on the phosphogypsum powder together, which not only reduces the addition amount of the hydration regulating auxiliary agent, but also ensures the utilization rate and filling rate of the phosphogypsum powder in the beta-hemihydrate phosphogypsum generated by the dihydrate phosphogypsum powder and the hydration regulating auxiliary agent, and at the same time reduces the cost of preparing the beta-hemihydrate phosphogypsum into phosphogypsum bricks.

[0074] On this basis, the raw material of the β-hemihydrate phosphogypsum of the present invention further includes short polypropylene fibers, and the short polypropylene fibers are evenly laid in the hydrated β-hemihydrate phosphogypsum. During the double-sided extrusion process of the β-hemihydrate phosphogypsum molding process, the pulling of the short polypropylene fibers in the β-hemihydrate phosphogypsum forms the initial strength of the phosphogypsum brickwork, so that the short polypropylene fibers can strengthen the strength of the phosphogypsum brickwork, so that the breaking load of the phosphogypsum brickwork can generally reach about 10000N (the industry 69 standard requires more than 2000N), and the compressive strength can generally reach more than 5MPa. Even if the product is loaded and transported immediately after it comes off the line, it will not be damaged due to the bumps during transportation. The problem of damage to the original phosphogypsum brickwork during transportation is fundamentally solved.

[0075] In addition, the hydration control auxiliary agent includes a dispersant and a resin, and the dispersant and the resin are prepared in a weight component ratio of 1: (2-3). In the present invention, the resin has the function of wrapping several water molecules in water to form granular water, and the dispersant has the function of dispersing water in phosphogypsum powder and dihydrate phosphogypsum powder, and preventing water from aggregating with phosphogypsum powder or dihydrate phosphogypsum powder to react with water, and at the same time, the dispersant and the resin are combined to wrap water molecules to form a granular water reservoir, and when the granular water reservoir is in a static state, the granular water reservoir will not hydrate with the phosphogypsum powder or dihydrate phosphogypsum powder, and the granular water reservoir can be evenly dispersed under the action of the dispersant.

[0076] In addition, the dispersant and resin designed in the present invention are formulated in a weight component ratio of 1: (2-3). In the market, the price of the resin is lower than that of the dispersant. Therefore, compared with the modifier in the prior art, the present invention reduces the addition of the modifier, thereby reducing the cost of preparing β-hemihydrate phosphogypsum into phosphogypsum bricks; in addition, the weight component of the resin accounts for 2-3 times that of the dispersant. Therefore, the water absorption rate of the resin is used to greatly increase the water storage capacity of the granular water reservoir, and the dispersant is used to reduce the viscosity and viscosity of the resin, thereby improving the flowability of the resin, so that the granular water reservoir formed by the resin-shaped water molecules can be evenly distributed on the surface of the phosphogypsum powder and the dihydrate phosphogypsum powder, which can improve the uniformity of hydration. At the same time, part of the granular water reservoir can remain attached to the surface of the phosphogypsum powder, so that the hydration reaction of the β-hemihydrate phosphogypsum is thorough during the extrusion process.

[0077] See also Figure 1 As shown, the pressurized molding structure in this embodiment includes a molding frame 1 and a vibration plate 2 arranged in sequence from top to bottom, with a certain distance between the molding frame 1 and the vibration plate 2, and a plurality of mold cavities 8 penetrating the molding frame 1 along the axial direction are evenly distributed in the molding frame 1, and all the mold cavities 8 together form an extrusion space, and a mold core 7 in a vertical state is provided in each mold cavity 8 along its axial direction, and the mold core 7 is suspended in the mold cavity 8, and the bottoms of all the mold cores 7 are fixed on the vibration plate 2, and a vibrator is installed on the vibration plate 2, and a plurality of through holes penetrating the vibration plate 2 along the axial direction are evenly distributed in the vibration plate 2, and the positions of the through holes correspond one by one to the positions of the mold cavities 8, and the starting point of the extrusion line in the double-sided extrusion structure is extruded toward the mold cavity 8, and the end point of the extrusion line passes through the through hole and is extruded toward the mold cavity 8.

[0078] When the hydrated β-hemihydrate phosphogypsum of the present invention is discharged into the mold cavity 8 in the molding frame 1, the vibrator drives the vibration plate 2 to vibrate, and the vibration plate 2 drives the mold core 7 in the mold cavity 8 to vibrate, and the mold core 7 drives the β-hemihydrate phosphogypsum to vibrate in the mold cavity 8, so that the β-hemihydrate phosphogypsum is evenly distributed in the mold cavity 8, so that the granular water reservoir attached to the incompletely hydrated phosphogypsum powder in the β-hemihydrate phosphogypsum can be relatively squeezed toward all the mold cavities 8 at the starting point and the end point of the extrusion line in the double-sided extrusion structure. The granular water reservoir can be broken in an instant to promote the rapid hydration of the phosphogypsum powder, so that the β-hemihydrate phosphogypsum is completely hydrated, and a certain amount of heat can be released to promote the rapid hardening of the β-hemihydrate phosphogypsum, thereby shortening the molding cycle. Compared with domestic and foreign wet production and domestic and foreign semi-dry production (non-continuous production), the molding cycle of the present invention is controlled between 25-30S, which greatly shortens the molding cycle and improves production efficiency.

[0079] Among them, spring columns 9 are installed at the four corners of the vibration plate 2 and the molding frame 1. When the vibrator vibrates, combined with a certain distance between the vibration plate 2 and the molding frame 1, the spring columns 9 cooperate with the vibrator to make the molding frame 1 shake up and down along the height direction. The vibration plate 2 has limit plates 11 on both sides and is installed on the lower press through the limit plates 11; the molding frame 1 has mounting strips 12 on both sides, the position of the mounting strips 12 corresponds to the position of the limit plates 11, and is installed on the lower press.

[0080] In addition, in the prior art, when the phosphogypsum hollow blocks are extruded and formed in a mold, the phosphogypsum hollow blocks are easily bonded to the mold, making it difficult to demold the phosphogypsum hollow blocks. Even if the phosphogypsum hollow blocks can be demolded, part of the surface of the phosphogypsum hollow blocks will be bonded to the mold, resulting in poor surface quality of the phosphogypsum hollow blocks.

[0081] To solve the above technical problems, see Figure 2 As shown, in this embodiment, the molding frame 1 is an integrated structure, and the inner surfaces of all the mold cavities 8 in the molding frame 1 are provided with several anti-sticking plates 13, and between adjacent anti-sticking plates 13 there are embedded steels 14 located at the corners in the mold cavity 8, and there is a gap between the embedded steels 14 and the anti-sticking plates 13.

[0082] Therefore, the present invention arranges several anti-sticking plates 13 on the inner surface of the mold cavity 8 to avoid the incompletely hydrated β-hemihydrate phosphogypsum being discharged during the extrusion process. The sticky lumps produced by the hydration of the phosphogypsum powder and the granular water reservoir in the incompletely hydrated β-hemihydrate phosphogypsum will not adhere to the anti-sticking plates 13, so that the heat generated during the hydration process of the phosphogypsum powder promotes the rapid hardening of the β-hemihydrate phosphogypsum. After hardening, the extruded phosphogypsum hollow blocks will not adhere to the anti-sticking plates 13, which is convenient for the phosphogypsum hollow blocks to be quickly demolded. At the same time, the embedded steel 14 between adjacent anti-sticking plates 13 can reduce the damage to the corner of the mold cavity 8 caused by the extrusion force applied during the extrusion process, thereby reducing the defective rate of the extruded phosphogypsum hollow blocks and improving the service life of the mold cavity 8.

[0083] In addition, the gaps between several adjacent anti-sticking plates 13 in the present invention have two functions: the first function is to provide space for the thermal expansion and contraction of the anti-sticking plates 13, so that the expansion of the anti-sticking plates 13 due to the heat generated after the hydration of the phosphogypsum powder will not squeeze the adjacent embedded steel 14, thereby avoiding the bulging of the surrounding side of the embedded steel 14 after being stressed, thereby affecting the service life of the mold cavity 8.

[0084] The second function is to provide a heat-insulating environment to the mold cavity 8. When the incompletely hydrated phosphogypsum powder in the β-hemihydrate phosphogypsum is vibrated and fed into the mold cavity 8, the incompletely hydrated phosphogypsum powder accumulates in the gap between the anti-sticking plate 13 and the embedded plate. The heat generated during the hydration of the phosphogypsum powder in the gap will be released into the mold cavity 8, thereby ensuring that the mold cavity 8 is in a relatively stable temperature environment, thereby accelerating and deepening the hydration reaction of the phosphogypsum powder, and quickly obtaining a completely final-set phosphogypsum hollow block.

[0085] The double-sided extrusion structure includes an upper mold and a lower mold, the upper mold is located at the starting point of the extrusion line, and the lower mold is located at the end point of the extrusion line. The upper mold and the lower mold move relative to each other toward the mold cavity 8, wherein the lower mold extends through the perforation toward the mold cavity 8 and maintains a relative position, and the upper mold moves away from the mold frame and toward the mold cavity 8 in the mold frame.

[0086] In the double-sided extrusion structure of the present invention, the upper mold and the lower mold serve as the starting point and the end point of the extrusion line extending in the direction through the extrusion space, respectively. At this time, before use, the lower mold extends through the perforation of the vibration plate 2 toward the mold cavity 8 to maintain a relative position, thereby achieving a closed state for the bottom of the mold cavity 8. When the β-hemihydrate phosphogypsum is discharged, it will first accumulate on the upper surface of the lower mold. At the same time, during the vibration process of the vibration plate 2, its lower mold and mold core 7 vibrate synchronously, so that the β-hemihydrate phosphogypsum can fall evenly and accumulate on the lower mold within the effective time. Then, the upper mold and the lower mold move relative to each other, the lower mold drives the β-hemihydrate phosphogypsum to move toward the upper mold, and the upper mold moves toward the mold cavity 8, thereby achieving rapid double-sided pressurization of the β-hemihydrate phosphogypsum, which can ensure high molding quality and improve production efficiency.

[0087] Among them, the upper mold part includes an upper pressure head, and the lower mold part includes a lower pressure head. An opening for the mold core 7 to pass through is opened in the middle position of the upper pressure head and the lower pressure head. The opposite surfaces of the upper pressure head and the lower pressure head are respectively installed with pressure plates 6, and the pressure plates 6 are made of anti-sticking material.

[0088] When the present invention is used, the upper pressure head first presses downward toward the mold cavity 8 with a pressure of 180 tons per second (18 MPa), stops moving when the path reaches 50 mm, and then presses upward toward the mold cavity 8 with a pressure of 230 tons per second (23 MPa) until the size guarantees the set height, and then presses for 3 seconds (static pressure for 3 seconds) to match the mold core 7 to form a phosphogypsum hollow block, the upper pressure head releases pressure, and the lower pressure head continues to push the phosphogypsum hollow block upward. The total duration of this process is 25S-30S. According to performance testing, the average duration is 26.2S, and it can work uninterruptedly, quickly pressurize on both sides, and can ensure high molding quality and improve production efficiency.

[0089] In addition, the pressure plate 6 in the present invention is made of a non-adhesive material. Therefore, during the extrusion process of the upper pressure head and the lower pressure head, the pressure plate 6 separates the upper pressure head or the lower pressure head from the β-hemihydrate phosphogypsum, avoiding the adhesion phenomenon of the β-hemihydrate phosphogypsum during the extrusion hydration process, and sticking to the upper pressure head and the lower pressure head, thereby facilitating the demoulding of the hollow phosphogypsum bricks from the mold cavity 8 and ensuring the surface quality of the hollow phosphogypsum blocks.

[0090] The upper mold component includes an upper mold base 4, and a plurality of upper mold columns 5 are provided on the end surface of the upper mold base 4 facing the mold cavity 8. The positions of the upper mold columns 5 correspond to the positions of the mold cavity 8 one by one, and the end surface of each upper mold column 5 facing the mold cavity 8 is fixedly connected to the upper pressure head; the lower mold component includes a lower mold base 3, and a plurality of lower mold columns 10 are provided under the end surface of the lower mold base 3 facing the mold cavity 8. The positions of the lower mold columns 10 correspond to the positions of the mold cavity 8 one by one, and each lower mold column 10 is fixedly connected to the end surface of the mold cavity 8 with the lower pressure head.

[0091] The upper mold base 4 used in the present invention supports a plurality of upper mold columns 5, each of which corresponds to the mold cavity 8 and can extend into the mold cavity 8, thereby driving the upper pressure head to be located in the mold cavity 8, and the lower mold base 3 used in the present invention supports a plurality of lower mold columns 10, each of which corresponds to the mold cavity 8 and can extend into the mold cavity 8, thereby driving the lower pressure head to be located in the mold cavity 8, so as to ensure that the upper pressure head and the lower pressure head can perform double-sided extrusion on β-hemihydrate phosphogypsum.

[0092] In addition, in this embodiment, the anti-sticking plate 13 and the pressing plate 6 are both made of polytetrafluoroethylene. Since polytetrafluoroethylene has the characteristics of minimum surface tension, no adhesion to any substance, and low friction coefficient, the mold cavity 8, as well as the upper and lower pressing heads, have the characteristics of no adhesion and friction resistance, thereby extending the service life of the mold cavity 8, the upper and lower pressing heads, and reducing the maintenance times and maintenance costs of the pressure molding structure and the double-sided extrusion structure.

[0093] The semi-dry continuous static pressing phosphogypsum hollow block production method comprises the following steps:

[0094] Step 1, lower mold preparation state: several lower mold columns 10 in the lower mold are passed through the vibration plate 2 together, and then all the lower mold columns 10 are extended into their respective corresponding mold cavities 8 and remain motionless;

[0095] Step 2, vibrating the material: When the β-hemihydrate phosphogypsum is poured into the mold cavity 8, the β-hemihydrate phosphogypsum is supported by the lower pressure head of the lower mold column 10. At this time, the vibrator on the vibration plate 2 receives a signal and starts to vibrate, driving all the mold cores 7 on the vibration plate 2 to shake, so that the β-hemihydrate phosphogypsum can fall evenly into the mold cavity 8 within the effective time;

[0096] Step 3, double-sided extrusion: the upper pressure head presses downward toward the mold cavity 8 at a pressure of 180 tons per second and 18 MPa, and stops moving when the travel distance reaches 50 mm, and then the lower pressure head presses upward toward the mold cavity 8 at a pressure of 230 tons per second and 23 MPa until the size guarantees the set height, and then presses for 3 seconds without moving, and matches with the mold core 7 to form a phosphogypsum hollow block;

[0097] Step 4: Push out of the mold: the upper pressure head releases the pressure, and the lower pressure head continues to push the phosphogypsum hollow blocks upward.

[0098] The production device of the present invention adopts a whole set of molds without welding points, and an integrally detachable mortise and tenon static pressure mold anchored with 12.9-grade high-strength screws. If damaged, the local original parts can be replaced according to the damaged parts. The plate of the mold is composed of two layers of different materials inside and outside. The supporting strength layer material is 45 steel plate. The material for demoulding is GB / T1299-2000 hard alloy tool steel. GB / T1299-2000 hard alloy tool steel is embedded steel 14. A reinforced and thickened vibration plate 2 is designed, and the mold core 7 is connected to the vibration plate. The mold core 7 and the vibration plate 2 are guaranteed to be 2mm apart. It is supported by heavy springs, and a vibrator is installed on the vibration plate 2. When the material is laid, the vibrator on the vibration plate 2 receives a signal and starts to vibrate, driving the mold core 7 on the vibration plate to shake, so that the mixture can evenly fall into the mold frame within the effective time. And the key technologies of integrally forming the corners of the side panels and hollowing out the whole plate are adopted. The size of the mold cavity 8 of the mold is designed based on the production needs of 600×200×200 (mm) hollow gypsum blocks and the design requirements of the number of molds. This can be used as a benchmark to design and develop molds for other specifications of products. A mold for producing 600×200×100 (mm) hollow phosphogypsum blocks has been developed. Each mold of the present invention can produce 9 600×200×100 (mm) hollow phosphogypsum block products.

[0099] Compare and explain from the aspects of technological advancement, economy, environmental protection level, management level, etc., and explain the technological innovation points, technical difficulties overcome and problems solved:

[0100] 1. The core parameters of this technology and its comparison with similar technology

[0101]

[0102]

[0103] 2. Comparative description of the technical advancement, economic efficiency, environmental protection level and management level of this technology and equipment

[0104] (1) Advanced technology

[0105] This process technology and equipment adopts key technologies such as adding admixture technology, high-speed shear mixing technology, B-type hydrated gypsum accelerator technology, rapid double-sided pressure molding technology, and natural curing technology using steam generated by the hydration heat of B-hemihydrate phosphogypsum. Compared with domestic and foreign wet production and discontinuous semi-dry production technologies, it has low water content, low product moisture content, short molding cycle and drying time, and high production capacity of a single set of equipment. It has been identified as an internationally advanced level by scientific and technological achievements.

[0106] (2) Economical

[0107] It is mainly reflected in saving construction land and energy saving. Off-line products do not need to be aired or dried, and can be directly packaged and shipped to users. A single set of equipment occupies an area of ​​2,000 m2, which can meet the needs of equipment installation, production and temporary storage of products at the same time. Compared with traditional wet production technology, it saves nearly 10 times the construction land; the product production water content is low, electricity is saved, and the product moisture content is low. It can be directly packaged and shipped to users without airing or drying. The unit water and electricity cost of the product is less than 10 yuan / m'. It is the best technical equipment for producing phosphogypsum hollow blocks in the world. The final manifestation is low investment, high production efficiency, and strong product profitability.

[0108] (3) Environmental protection level

[0109] The environmental protection level of this technical equipment is mainly reflected in two aspects. First, it has a strong ability to utilize industrial by-product phosphogypsum for desulfurization of gypsum. A single set of equipment can utilize an average of 110,000 tons of industrial by-product phosphogypsum per year; second, there is no discharge of waste water, waste gas, waste residue and waste products during the production process. It is currently the technical equipment with the highest environmental protection level for producing phosphogypsum hollow blocks in the world.

[0110] The above are only embodiments of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. Semi-dry continuous static pressure phosphogypsum hollow block production device, including: The pressurized molding structure is configured to have a non-sticking extrusion space capable of continuous vibration to feed β-hemihydrate phosphogypsum. The raw materials of the β-hemihydrate phosphogypsum include phosphogypsum powder, dihydrate phosphogypsum powder, a hydration control agent, and water. The phosphogypsum powder is used to delay the hydration reaction time of the dihydrate phosphogypsum powder and allow sufficient time for the two to be fully mixed with the water. The dihydrate phosphogypsum powder is used to accelerate the hydration rate of the phosphogypsum powder. The hydration control agent is used to initially separate water molecules from the phosphogypsum powder and the dihydrate phosphogypsum powder, and to wrap several water molecules in the water to form a granular water reservoir. During the hydration process, part of the granular water reservoir is dispersed in the phosphogypsum powder environment and adheres to the surface of the phosphogypsum particles and the dihydrate phosphogypsum powder. The double-sided extrusion structure is configured to have an extrusion line extending in a direction passing through the extrusion space, wherein a starting point and an end point of the extrusion line mutually form relative extrusion forces toward the extrusion space.

2. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 1, characterized in that: The raw materials of the β-hemihydrate phosphogypsum also include polypropylene staple fibers, wherein the weight component of the phosphogypsum powder is 100 parts, the weight component of the dihydrate phosphogypsum powder is 8-10 parts, the weight component of the polypropylene staple fibers is 0.05-0.1 parts, the weight component of the hydration control auxiliary agent is 0.1-0.2 parts, and the weight component of the water is 28-32 parts.

3. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 1, characterized in that: The hydration control auxiliary agent includes a dispersant and a resin, and the dispersant and the resin are prepared in a weight ratio of 1:(2-3).

4. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 1, characterized in that: The pressurized molding structure includes a molding frame and a vibration plate arranged in sequence from top to bottom, with a certain distance between the molding frame and the vibration plate. Several mold cavities are evenly distributed in the molding frame and penetrate the molding frame along the axial direction. All the mold cavities together form an extrusion space. A mold core in a vertical state is provided in each mold cavity along its axial direction. The mold core is suspended in the mold cavity. The bottoms of all the mold cores are fixed on the vibration plate. A vibrator is installed on the vibration plate. Several through-holes are evenly distributed in the vibration plate and penetrate the vibration plate along the axial direction. The positions of the through-holes correspond one-to-one to the positions of the mold cavities. The starting point of the extrusion line in the double-sided extrusion structure is extruded toward the mold cavity, and the end point of the extrusion line passes through the through-hole and is extruded toward the mold cavity.

5. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 4, characterized in that: The forming frame is an integrated structure. The inner surfaces of all mold cavities in the forming frame are provided with several anti-sticking plates. There is embedded steel located at the corners of the mold cavity between adjacent anti-sticking plates, and there is a gap between the embedded steel and the anti-sticking plate.

6. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 4, characterized in that: The double-sided extrusion structure includes an upper mold and a lower mold, the upper mold is located at the starting point of the extrusion line, and the lower mold is located at the end point of the extrusion line. The upper mold and the lower mold move relative to each other toward the mold cavity, wherein the lower mold extends toward the mold cavity through the through hole and maintains a relative position, and the upper mold moves away from the mold frame and toward the mold cavity in the mold frame.

7. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 6, characterized in that: The upper mold includes an upper pressure head, and the lower mold includes a lower pressure head. An opening for the mold core to pass through is opened in the middle of the upper pressure head and the lower pressure head. Pressure plates are respectively installed on the opposite surfaces of the upper pressure head and the lower pressure head, and the pressure plates are made of anti-sticking material.

8. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 7, characterized in that: The upper mold part includes an upper mold base, and a plurality of upper mold columns are provided on the end surface of the upper mold base facing the mold cavity. The positions of the upper mold columns correspond one-to-one to the positions of the mold cavity, and the end surface of each upper mold column facing the mold cavity is fixedly connected to the upper pressure head; the lower mold part includes a lower mold base, and a plurality of lower mold columns are provided under the end surface of the lower mold base facing the mold cavity. The positions of the lower mold columns correspond one-to-one to the positions of the mold cavity, and each lower mold column is fixedly connected to the end surface facing the mold cavity with the lower pressure head.

9. The semi-dry continuous static pressure phosphogypsum hollow block production device according to claim 7, characterized in that: The anti-sticking plate and the pressing plate are both made of polytetrafluoroethylene.

10. A method for producing a semi-dry continuous statically pressed phosphogypsum hollow block production device, applied to the semi-dry continuous statically pressed phosphogypsum hollow block production device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Lower mold preparation: Several lower mold columns in the lower mold pass through the vibration plate together, and then all lower mold columns extend into their corresponding mold cavities and remain stationary; Step 2: Vibration distribution: When β-hemihydrate phosphogypsum is poured into the mold cavity, the β-hemihydrate phosphogypsum is supported by the lower pressure head of the lower mold column. At this time, the vibrator on the vibration plate receives a signal and starts vibrating, driving all the mold cores on the vibration plate to shake, so that the β-hemihydrate phosphogypsum can fall evenly into the mold cavity within an effective time. Step 3, double-sided extrusion: The upper pressure head presses downward toward the mold cavity at a pressure of 180 tons per second and 18 MPa, and stops moving when the travel distance reaches 50 mm. Then the lower pressure head presses upward toward the mold cavity at a pressure of 230 tons per second and 23 MPa until the size meets the set height. Then, it remains stationary for 3 seconds to match the mold core to form a phosphogypsum hollow block. Step 4: Push out of the mold: the upper pressure head releases the pressure, and the lower pressure head continues to push the phosphogypsum hollow blocks upward.

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