Preparation method of hardened gypsum particles

Abstract

The invention discloses a hardened gypsum particle preparation method, which comprises the following steps: crushing industrial phosphogypsum waste residue, screening to remove impurities to obtain 50-60 [mu] m solid waste, conveying the phosphogypsum solid waste to a calcining and drying all-in-one machine, calcining at 120-160 DEG C for 2-3 h, and dehydrating the phosphogypsum solid waste into beta-semi-hydrated gypsum powder; appropriate compound fertilizer pH value dilution water is prepared for standby application according to the pH value of a used land parcel; s4, prepared dilution water is injected into a running drum type pelletizer, then semi-hydrated gypsum powder and CaCO3 are put into the drum type pelletizer to be mixed and hydrated, and hardened gypsum (dihydrate gypsum) particles are prepared. The hardened gypsum particles prepared through the method have adsorbability, water absorption and air permeability and can improve the acid-base property of soil at the same time; due to the characteristics, the method plays an important role in various application scenes; the method opens up a new way for comprehensive utilization of phosphogypsum, and has remarkable economic benefits and environmental benefits.

Description

Technical Field

[0001] The present invention belongs to the technical fields of building materials and environmental protection, and particularly relates to a method for preparing hardened gypsum particles from β - hemihydrate gypsum. Background Art

[0002] Although the β - hemihydrate gypsum powder prepared by calcining phosphogypsum is applied in building construction wall, wall surface, floor materials, etc., at present, the stockpile of phosphogypsum is as high as about 800 million tons, and the annual new increment is considerable, resulting in poor utilization rate. Developing new utilization ways to consume phosphogypsum and at the same time preparing products with wide application value is of great significance.

[0003] The present invention proposes a method for preparing hardened gypsum particles. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing hardened gypsum particles to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A method for preparing hardened gypsum particles, the specific steps include:

[0006] S1: First, the industrial phosphogypsum waste residue is crushed and screened to remove impurities;

[0007] S2: The phosphogypsum solid waste obtained after the treatment in step S1 is transported to a calcining and drying integrated machine by a belt conveyor, the calcining temperature is 120°C - 160°C, and the time is 2 - 3h, so that the phosphogypsum solid waste is dehydrated into β - hemihydrate gypsum powder;

[0008] S3: Prepare a suitable compound fertilizer pH - adjusted dilution water according to the pH value of the used plot for standby;

[0009] S4: Inject the prepared dilution water into the running drum granulator, and then put in β - hemihydrate gypsum powder and CaCO3 for mixed hydration to prepare hardened gypsum particles. The mixing ratio of the dilution water to β - hemihydrate gypsum powder and to CaCO3 is 45:1000:100.

[0010] Preferably, in S1, after the industrial phosphogypsum waste residue is crushed and screened, the particle size of the phosphogypsum solid waste is 50um - 60um, and the humidity is 10% - 20%.

[0011] Preferably, in S4, the particle size range of the prepared hardened gypsum particles is 1 - 170mm.

[0012] Preferably, in S2, the heat source is transported from the tail of the calcination and drying machine to the front end of the calcination and drying machine to release the heat source, and the incoming phosphogypsum solid waste is stir-fried and calcined. The calcined phosphogypsum solid waste is dried by the heat released by the wall of the pipe that transports the heat source. After drying, the β-hemihydrate gypsum is discharged from the calcination and drying machine and transported to an aging tank for storage.

[0013] Preferably, in S4, a pH detection instrument can be used to determine the pH of the soil in the plot to be used; according to the detection results, a suitable compound fertilizer raw material is selected for preparation; the compound fertilizer raw material is added to water in a certain proportion, and stirred sufficiently to completely dissolve the compound fertilizer to obtain uniform dilution water. The pH value of the dilution water is detected to ensure that it meets the predetermined pH requirement.

[0014] Preferably, in the S4, the particle size of CaCO3 is less than or equal to 90 um.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The hardened gypsum particles prepared by the present invention have adsorption, water absorption, air permeability and can improve the acidity and alkalinity of the soil; these characteristics make it play an important role in various application scenarios;

[0017] Landscape application: It can be used for paving and landscaping in cities, scenic spots and courtyards to provide unique landscape effects. At the same time, its physical properties can help improve the local environment.

[0018] Ecological restoration: It is suitable for covering ecological restoration in rocky desertification areas; as long as there is a certain amount of rainfall in the covered area, the adsorption, water absorption and air permeability of the particles can assist the vegetation to regenerate and promote the improvement of the ecological environment;

[0019] Desert control: Without considering the transportation route, by covering the desert with different particle sizes, it is possible to prevent the dust from being blown up and not hinder the growth of desert drip irrigation plants; if it is not far from the drip irrigation plants, it can also be used as epiphyte vegetation to improve the desert environment, and it can be naturally degraded without causing secondary pollution to the desert environment; at the same time, this application can absorb a large amount of phosphogypsum, effectively reducing the storage pressure of phosphogypsum;

[0020] The invention opens up a new way for the comprehensive utilization of phosphogypsum and has significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the process flow of the present invention; DETAILED DESCRIPTION

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figure 1 , the present invention provides a technical solution:

[0024] Example 1

[0025] A method for preparing hardened gypsum particles, the specific steps include:

[0026] S1: First, the industrial phosphogypsum waste residue is crushed and screened to remove impurities;

[0027] S2: The phosphogypsum solid waste obtained after the treatment in step S1 is transported to a calcination and drying integrated machine by a belt conveyor, the calcination temperature is 120-160°C, and the time is 2-3h, so that the phosphogypsum solid waste is dehydrated into β-hemihydrate gypsum powder;

[0028] S3: Prepare a suitable compound fertilizer pH dilution water for standby according to the pH of the used plot;

[0029] S4: Inject the prepared dilution water into the running drum granulator, and then put in β-hemihydrate gypsum powder and CaCO3 for mixed hydration to prepare hardened gypsum particles. The mixing ratio of the dilution water to β-hemihydrate gypsum powder and to CaCO3 is 45:1000:100.

[0030] In this embodiment, preferably, in S1, after the industrial phosphogypsum waste residue is crushed and screened, the particle size of the phosphogypsum solid waste is 50um-60um, and the humidity is 10%-20%.

[0031] In this embodiment, preferably, in S4, the particle size of the prepared hardened gypsum particles is 1-170mm.

[0032] In this embodiment, preferably, in S2, the heat source is conveyed from the tail of the calcination and drying integrated machine to the front end of the calcination and drying integrated machine to release the heat source, and the incoming phosphogypsum solid waste is stir-fried and calcined. The phosphogypsum solid waste after calcination is dried by the heat released through the pipe wall of the heat source conveyor. After drying, β-hemihydrate gypsum is discharged from the calcination and drying integrated machine and transported to the aging tank for storage.

[0033] In this embodiment, preferably, in S4, a pH detector can be used to measure the soil pH value of the plot to be used; according to the test results, appropriate compound fertilizer raw materials are selected for blending; the compound fertilizer raw materials are added into water in a certain proportion and stirred thoroughly to completely dissolve the compound fertilizer, obtaining uniform diluted water. By detecting the pH value of the diluted water, it is ensured that the diluted water meets the predetermined pH requirements.

[0034] In this embodiment, preferably, in S4, the particle size of CaCO3 ≤ 90um.

[0035] Embodiment 2

[0036] A method for preparing hardened gypsum particles, the specific steps include:

[0037] S1: First, the industrial phosphogypsum waste residue is crushed and screened to remove impurities;

[0038] S2: The phosphogypsum solid waste obtained after the treatment in step S1 is transported to a calcination and drying integrated machine by a belt conveyor, the calcination temperature is 120 - 160 °C, and the time is 2 - 3 h, so that the phosphogypsum solid waste is dehydrated into β - hemihydrate gypsum powder;

[0039] S3: Prepare a compound fertilizer pH - adjusted diluted water suitable for the plot to be used according to the soil pH value for standby;

[0040] S4: Inject the prepared diluted water into the running drum granulator, and then put in β - hemihydrate gypsum powder and CaCO3 for mixed hydration to prepare hardened gypsum particles, and the mixing ratio of the diluted water, β - hemihydrate gypsum powder and CaCO3 is 45:1000:100.

[0041] In this embodiment, preferably, in S1, after the industrial phosphogypsum waste residue is crushed and sieved, the particle size of the phosphogypsum solid waste is 50um - 60um, and the humidity is 10% - 20%.

[0042] In this embodiment, preferably, in S4, the particle diameter of the prepared hardened gypsum particles is 1 - 170mm.

[0043] In this embodiment, preferably, in S2, heat source is transported from the tail of the calcination and drying integrated machine to the front end of the calcination and drying integrated machine to release the heat source, stir - fry and calcine the incoming phosphogypsum solid waste, and the phosphogypsum solid waste after calcination is dried by the heat released from the pipe wall for transporting the heat source. After drying, the β - hemihydrate gypsum powder is discharged from the calcination and drying integrated machine and transported to the aging tank for storage.

[0044] In this embodiment, preferably, in S4, a pH detection instrument can be used to measure the pH of the soil in the plot to be used; according to the detection result, a suitable compound fertilizer raw material is selected for preparation; the compound fertilizer raw material is added to water in a certain proportion, and stirred sufficiently to completely dissolve the compound fertilizer to obtain uniform dilution water. By detecting the pH value of the dilution water, it is ensured that it meets the predetermined pH requirement.

[0045] In this embodiment, preferably, in S4, the particle size of CaCO3 is ≤90um.

[0046] Although the embodiments of the present invention have been shown and described, as detailed above, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing hardened gypsum particles, characterized in that: The specific steps include: S1: First, the industrial phosphogypsum waste residue is crushed and screened to remove impurities; S2: transporting the phosphogypsum solid waste obtained after the treatment in step S1 to a calcination and drying integrated machine by a belt conveyor, and calcining at a temperature of 120° C. to 160° C. for 2 to 3 hours to dehydrate the phosphogypsum solid waste into β-hemihydrate gypsum powder; S3: Prepare the appropriate compound fertilizer dilution water according to the pH of the land for use; S4: inject the prepared dilution water into the running drum granulator, and then add β-semihydrate gypsum powder and CaCO3 for mixing and hydration to prepare hardened gypsum particles. The mixing ratio of dilution water to β-semihydrate gypsum powder and CaCO3 is 45:1000:

100.

2. A method for preparing hardened gypsum particles according to claim 1, characterized in that: In S1, after the industrial phosphogypsum waste residue is crushed and screened, the particle size of the phosphogypsum solid waste is 50um-60um and the humidity is 10%-20%.

3. The method for preparing hardened gypsum particles according to claim 1, characterized in that: In S4, the particle size range of the hardened gypsum particles obtained is 1-170 mm.

4. The method for preparing hardened gypsum particles according to claim 1, characterized in that: In S2, a heat source is transported from the tail of the calcining and drying machine to the front end of the calcining and drying machine to release the heat source, and the incoming phosphogypsum solid waste is stir-fried and calcined. The calcined phosphogypsum solid waste is dried by the heat released by the wall of the pipe that transports the heat source. After drying, β-hemihydrate gypsum is prepared and discharged from the calcining and drying machine and transported to an aging tank for storage.

5. The method for preparing hardened gypsum particles according to claim 1, characterized in that: In S4, a pH detection instrument can be used to determine the pH of the soil in the plot of land to be used; according to the detection results, suitable compound fertilizer raw materials are selected for preparation; the compound fertilizer raw materials are added to water in a certain proportion, and stirred sufficiently to completely dissolve the compound fertilizer to obtain uniform dilution water. The pH value of the dilution water is detected to ensure that it meets the predetermined pH requirements.

6. The method for preparing hardened gypsum particles according to claim 1, characterized in that: In the S4, the particle size of CaCO3 is less than or equal to 90 um.

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