Gypsum waste recycling method and paddle crusher used for same

Abstract

The invention provides a gypsum waste recycling method which comprises gypsum dry waste and gypsum wet waste and comprises the following steps: step 100, crushing the gypsum dry waste and the gypsum wet waste for the first time respectively to obtain a dry waste coarse material and a wet waste coarse material respectively; step 200, stacking the dry waste coarse material and the wet waste coarse material in a layered manner; step 300, performing primary screening on the stacked mixture, and separating out fine gypsum particles and a coarse material of the mixture; step 400, carrying out secondary crushing on the coarse material of the mixed material to obtain a fine material of the mixed material; step 500, carrying out secondary screening on the fine mixed material, and separating out paper scraps and gypsum particles; and step 600, screening the gypsum particles for three times to separate out fine gypsum particles and coarse gypsum particles. The invention further provides a paddle type crusher for secondary crushing.

Description

Technical Field

[0001] The invention relates to building materials, in particular to the recycling of gypsum waste. Background Art

[0002] In the process of gypsum board production, a large amount of waste is generated, including dry waste and wet waste. Dry waste includes dry gypsum waste board, gypsum bars and dry gypsum blocks, and wet waste includes gypsum board waste that has not yet dried (wet gypsum waste board) and start-up waste (wet gypsum blocks).

[0003] At present, gypsum waste can only be disposed of in landfill as construction waste, which not only pollutes the environment and incurs extremely high costs, but also causes waste of materials. Summary of the invention

[0004] The object of the present invention is to provide a method for recycling gypsum waste.

[0005] To this end, according to one aspect of the present invention, a method for recycling gypsum waste, wherein the gypsum waste includes dry gypsum waste and wet gypsum waste, comprises the following steps:

[0006] Step 100, crushing the dry gypsum waste and the wet gypsum waste to obtain dry waste coarse material and wet waste coarse material respectively;

[0007] Step 200, stacking the dry waste coarse material and the wet waste coarse material in layers;

[0008] Step 300, screening the accumulated mixed material to separate fine gypsum particles and coarse mixed material;

[0009] Step 400, performing secondary crushing on the coarse mixed material to obtain fine mixed material;

[0010] Step 500, secondary screening of the mixed material fines to separate paper scraps and gypsum particles;

[0011] Step 600, screening the gypsum particles three times to separate fine gypsum particles and coarse gypsum particles.

[0012] Further, in step 100, the primary crushing includes: crushing the wet gypsum waste by rolling crushing; and crushing the dry gypsum waste to a certain size by tearing crushing.

[0013] Wherein, in step 200, the layered stacking includes: stacking the layers formed by the dry waste coarse material and the layers formed by the wet waste coarse material at intervals; and making the moisture content of the mixture below 10 wt.% based on the total weight of the mixture.

[0014] Wherein, the particle size of the fine gypsum particles is less than or equal to 3 mm.

[0015] Wherein, in step 400, the coarse mixed material is subjected to secondary crushing by using a paddle crusher, wherein the paddle crusher is provided with a plurality of paddles, and the number of blades of each paddle gradually increases along the conveying direction of the coarse mixed material.

[0016] In step 500, the mixed material fine material is secondary screened by using a drum screen, and the drum screen is vibrated.

[0017] Wherein, in step 600, it also includes: further crushing the coarse gypsum particles into fine gypsum particles.

[0018] Before the secondary crushing in step 400, the method further includes:

[0019] Step 350, using a magnetic device to separate iron impurities in the mixed material.

[0020] Furthermore, the method further includes step 700 of recycling the paper scraps. The step includes:

[0021] Step 710, soaking the paper scraps in water to form paper pulp;

[0022] Step 720, breaking up the primary pulp and adding water to form secondary pulp;

[0023] Step 730: centrifuge the secondary pulp to obtain pulp fibers.

[0024] In addition, according to another aspect of the present invention, a paddle crusher is provided, which is used for secondary crushing in step 400 of the above method. The paddle crusher has a rotating shaft, on which are provided a plurality of paddles arranged along the axial direction of the rotating shaft, wherein the number of blades of the paddles gradually increases along the axial direction of the rotating shaft.

[0025] The present invention can realize the complete recycling of gypsum waste, thereby achieving zero landfill, which not only protects the environment but also saves processing costs and raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flowchart of an embodiment of the method according to the present invention.

[0027] Figure 2 It is a paddle crusher used for secondary crushing in the method of the present invention. DETAILED DESCRIPTION

[0028] The specific implementation of the present application is described below with reference to the accompanying drawings.

[0029] See also Figure 1 A method for recycling gypsum waste can simultaneously recycle dry gypsum waste and wet gypsum waste. The dry gypsum waste is dried gypsum waste, including (but not limited to) dry gypsum waste boards, dry gypsum blocks and broken gypsum bars. The wet gypsum waste is undried gypsum waste, including (but not limited to) wet gypsum waste boards and wet gypsum blocks.

[0030] First, if Figure 1 As shown, in step 100, the dry gypsum waste and the wet gypsum waste are respectively crushed once. The crushing may be performed by any suitable equipment, even manually. For example, in one example, the wet gypsum waste board may be crushed once by a rolling crushing equipment. In another example, the dry gypsum waste may be crushed once by a tearing crushing equipment. In another example, the wet gypsum block may be crushed once by an extrusion crushing equipment.

[0031] The present application does not specifically limit the size of the crushed gypsum waste, as long as it can meet the requirements of the equipment used to complete the subsequent steps for the size of the raw materials. After the primary crushing, dry waste coarse material and wet waste coarse material are obtained.

[0032] Step 200, stacking the gypsum waste after the primary crushing. The dry waste coarse material and the wet waste coarse material are stacked in layers. That is, at least one layer composed of the dry waste coarse material and at least one layer composed of the wet waste coarse material form a substantially stacked structure, and adjacent layers are respectively a dry waste coarse material layer and a wet waste coarse material layer.

[0033] In combination with step 100, in one embodiment, during the primary crushing, a portion of the dry gypsum waste can be crushed to form a dry waste coarse material layer, and then a portion of the wet gypsum waste can be crushed to form a wet waste coarse material layer on the dry waste coarse material layer. The aforementioned process is repeated to form a stacked structure with multiple dry waste coarse material layers and multiple wet waste coarse material layers.

[0034] Alternatively, in another embodiment, all the dry gypsum waste and the wet gypsum waste may be crushed once respectively to form a stacked structure with dry waste coarse material layers and wet waste coarse material layers alternately spaced.

[0035] According to step 200, the method further includes leaving the mixture of the stacked structure to stand for a certain period of time so that the moisture content in the mixture of the stacked structure is less than 10% of the total weight of the mixture.

[0036] As shown in step 300, the mixture with a moisture content of less than 10% is screened once to separate fine gypsum particles and coarse mixture. The fine gypsum particles can be particles generated in the primary crushing or particles adhered to wet gypsum waste. The particle size of the fine gypsum particles is less than or equal to 3 mm. The primary screening can be completed using a screening device with an aperture of 3 mm, such as a screen with an aperture of 3 mm.

[0037] In one example, for gypsum waste containing iron materials, such as post-consumer recycled gypsum board waste, fixing screws, keel parts, etc. may be mixed therein. Therefore, a magnetic device may be used to remove the iron impurities from the mixed material coarse material, step 350.

[0038] Step 400, secondary crushing of the coarse mixture. The secondary crushing can be performed using a paddle crusher to obtain fine mixture. Figure 2 As shown, the paddle crusher is provided with a plurality of paddles on its rotating shaft for crushing materials. The number of the paddles gradually increases along the conveying direction of the materials. That is, the number of the paddles arranged upstream of the conveying direction of the coarse mixed material is relatively small, and the number of the paddles arranged downstream of the conveying direction is relatively large. The gypsum waste particles are crushed step by step to achieve the desired gypsum particle size of less than or equal to 3 mm.

[0039] To this end, in another embodiment of the present invention, a paddle crusher 10 is provided for the above-mentioned secondary crushing.

[0040] It has a transmission shaft 12 , on which a plurality of blades 14 are arranged along the axial direction of the transmission shaft 12 , wherein the number of blades of the blades 14 gradually increases along the axial direction of the transmission shaft 12 .

[0041] Step 500: Perform secondary screening on the mixed material fine material to separate paper scraps and gypsum particles. The secondary screening can be performed using a drum screen, and the drum screen is vibrated intermittently or continuously during the screening process.

[0042] The gypsum particles screened out in step 500 include fine gypsum particles and coarse gypsum particles. As mentioned above, gypsum particles with a particle size less than 3 mm are fine gypsum particles, which can be used as raw materials together with desulfurized gypsum. Gypsum particles with a particle size greater than 3 mm are coarse gypsum particles.

[0043] In step 600, the gypsum particles are further sieved three times to separate fine gypsum particles and coarse gypsum particles. Furthermore, in step 600, the coarse gypsum particles can also be crushed into fine gypsum particles.

[0044] The paper scraps screened out in step 500 can also be recycled, such as step 700, further comprising: step 710, soaking the paper scraps in water once to form primary pulp; step 720, breaking the primary pulp and adding water to form secondary pulp; and step 730, centrifugally separating the secondary pulp to obtain pulp fibers. The pulp fibers can be used as organic fiber materials for the manufacture of gypsum boards.

[0045] Through the above method, most of the materials in the gypsum waste can be reused in the production of gypsum boards or gypsum powder, and the recovery rate of the gypsum waste is close to 100%.

[0046] In the above description, the details of the technical solution of the present application are explained. However, those skilled in the art will appreciate that the present application is not limited to the specific details listed in the above embodiments, but may vary within the scope defined by the claims.

Claims

1. A method for recycling gypsum waste, wherein the gypsum waste includes dry gypsum waste and wet gypsum waste, and the method comprises the following steps: Step 100, crushing the dry gypsum waste and the wet gypsum waste to obtain dry waste coarse material and wet waste coarse material respectively; Step 200, stacking the dry waste coarse material and the wet waste coarse material in layers; Step 300, screening the accumulated mixed material to separate fine gypsum particles and coarse mixed material; Step 400, performing secondary crushing on the coarse mixed material to obtain fine mixed material; Step 500, secondary screening of the mixed material fines to separate paper scraps and gypsum particles; Step 600, screening the gypsum particles three times to separate fine gypsum particles and coarse gypsum particles.

2. The method for recycling gypsum waste according to claim 1, characterized in that: In step 100, the primary crushing includes: crushing the wet gypsum waste by rolling crushing; and crushing the dry gypsum waste to a certain size by tearing crushing.

3. The method for recycling gypsum waste according to claim 1, characterized in that: In step 200, the layered stacking includes: so that a layer formed of the dry waste coarse material is stacked alternately with a layer formed of the wet waste coarse material; and The moisture content of the mixture is made to be less than 10 wt. % based on the total weight of the mixture.

4. The method for recycling gypsum waste according to claim 1, characterized in that: The particle size of the fine gypsum particles is less than or equal to 3 mm.

5. The method for recycling gypsum waste according to claim 1, characterized in that: In step 400, the coarse mixed material is subjected to secondary crushing by using a paddle crusher, wherein the paddle crusher is provided with a plurality of paddles, and the number of blades of each paddle gradually increases along the conveying direction of the coarse mixed material.

6. The method for recycling gypsum waste according to claim 1, characterized in that: In step 500, the mixed material fine material is secondary screened by using a drum screen, and the drum screen is vibrated.

7. The method for recycling gypsum waste according to claim 1, characterized in that: In step 600, the method further includes: further crushing the coarse gypsum particles into fine gypsum particles.

8. The method for recycling gypsum waste according to claim 1, characterized in that: Before the secondary crushing in step 400, the method further includes: Step 350, using a magnetic device to separate iron impurities in the mixed material.

9. The method for recycling gypsum waste according to claim 1, characterized in that: The method further comprises step 700 of recycling the paper scraps; wherein the step comprises: Step 710, soaking the paper scraps in water to form paper pulp; Step 720, breaking up the primary pulp and adding water to form secondary pulp; Step 730: centrifuge the secondary pulp to obtain pulp fibers.

10. A paddle crusher, used for secondary crushing in step 400 of the method according to any one of claims 1 to 9, wherein the paddle crusher has a rotating shaft, and the rotating shaft is provided with a plurality of paddles arranged along the axial direction of the rotating shaft, wherein: Along the axial direction of the rotating shaft, the number of blades of the paddle gradually increases.

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