CN114956624B - Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum - Google Patents
Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum Download PDFInfo
- Publication number
- CN114956624B CN114956624B CN202210627289.4A CN202210627289A CN114956624B CN 114956624 B CN114956624 B CN 114956624B CN 202210627289 A CN202210627289 A CN 202210627289A CN 114956624 B CN114956624 B CN 114956624B
- Authority
- CN
- China
- Prior art keywords
- phosphogypsum
- strength
- hemihydrate gypsum
- percent
- industrial byproduct
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B11/00—Calcium sulfate cements
- C04B11/26—Calcium sulfate cements strating from chemical gypsum; starting from phosphogypsum or from waste, e.g. purification products of smoke
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention discloses a method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum. The phosphogypsum is used as a raw material to prepare the alpha hemihydrate gypsum by a steam pressing method. The method comprises the following specific steps: taking the phosphogypsum doped with defluorination residues and washed and purified by water as a raw material, uniformly stirring the phosphogypsum raw material and a solution of a crystal transformation agent in a stirrer, then conveying the mixture into an autoclave, setting the reaction temperature and the stirring speed to reach the set reaction temperature, reacting at a constant temperature for 20 to 120min, then releasing the pressure out of the autoclave, drying at 80 to 130 ℃, and grinding to obtain an alpha ultrahigh-strength gypsum product. The alpha semi-hydrated gypsum prepared by the method has stable quality, the strength is higher than the standard JC/T2038-2010 alpha 50 highest grade, the problem of low strength of the alpha semi-hydrated gypsum prepared from the phosphogypsum raw material is solved, the waste is changed into valuable, and the high-value utilization of the industrial byproduct phosphogypsum is further promoted.
Description
Technical Field
The invention relates to a method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum, and belongs to the technical field of building materials.
Background
Phosphogypsum (phosphogypsum) is an industrial byproduct obtained in the production of wet-process phosphoric acid and phosphorus compound fertilizer, and the main component of the phosphogypsum is CaSO 4 ·2H 2 O, 1tP per production 2 O 5 4 to 5t of phosphogypsum can be produced. The phosphogypsum contains various harmful impurities such as phosphorus, fluorine, organic matters and the like, so that the phosphogypsum has extremely unstable performance, low utilization rate and large-scale stockpiling; the long-term stacking of the phosphogypsum not only occupies a large amount of land resources, but also causes pollution to soil and rivers due to the fact that impurities such as water-soluble phosphorus and water-soluble fluorine in the phosphogypsum are soaked in the soil and the rivers, and therefore a series of ecological problems are caused. The crystal transformation preparation of the alpha hemihydrate gypsum by taking the phosphogypsum as the raw material is one of effective ways for realizing high-value utilization of the phosphogypsum.
Alpha hemihydrate gypsum (alpha-CaSO) 4 ·0.5H 2 O) is a cementing material with excellent performance, high strength and wide application, and needs hydration hardening processLess water, low heat generation and high strength of the product. The high-strength gypsum product using alpha semi-hydrated gypsum as raw material is used in various fields of ceramic mould, precision casting, industrial art, dental superhard material, self-leveling, mortar and fire door core plate, etc.
The defluorination residue is residue generated in the process of preparing feed grade calcium hydrophosphate from sewage, and the main components of the defluorination residue are calcium phosphate, calcium fluoride and the like. Researches show that the mechanical properties of the alpha hemihydrate gypsum prepared by adding a proper amount of defluorination residues in the phosphogypsum washing pretreatment process can be improved.
Disclosure of Invention
The invention aims to solve the technical problems that the alpha hemihydrate gypsum product prepared from phosphogypsum has low strength and the phosphogypsum-based alpha hemihydrate gypsum product has low strength and cannot meet the requirements of downstream products such as fireproof door core plates, floor heating plates, self-leveling products, ceramic mold gypsum and the like.
The technical scheme of the invention is as follows: a method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum comprises the following specific steps:
(1) Phosphogypsum pretreatment and purification: mixing phosphogypsum with defluorination residues, washing and removing impurities;
(2) Preparing a crystal transformation agent solution: dissolving calcium hydroxide, succinic acid, maleic acid, potassium sodium tartrate, sodium citrate and aluminum sulfate in water to prepare a crystal modifier solution;
(3) Stirring: adding the phosphogypsum purified in the step (1) into the crystal transformation agent solution prepared in the step (2) in a stirrer and uniformly stirring;
(4) And (3) carrying out autoclaved reaction: conveying the phosphogypsum material uniformly stirred in the step (3) and mixed with the crystal transformation agent into an autoclave, sealing, setting the reaction temperature and the stirring speed, heating to the reaction temperature, and reacting at constant temperature for a period of time;
(5) Drying and grinding: and after the autoclave reaction is finished, releasing pressure, taking out of the kettle, drying and grinding to obtain the ultrahigh-strength alpha semi-hydrated gypsum.
In the method, the doping amount of the defluorination residues in the step (1) is 1 to 5 percent of the dry basis mass fraction of the phosphogypsum.
In the method, after the phosphogypsum in the step (1) is washed and purified by water, the pH value is 5 to 6.5.
In the method, the content of the raw material, namely the phosphogypsum, calcium sulfate dihydrate in the step (1) is more than 85 percent.
The solution of the crystal transformation agent in the step (2) is prepared according to the following proportion: the calcium hydroxide accounts for 0.1 to 2 percent of the dry basis mass of the phosphogypsum; the succinic acid accounts for 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the mass of the maleic acid is 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the potassium sodium tartrate accounts for 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the sodium citrate accounts for 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the aluminum sulfate accounts for 0 to 1 percent of the dry basis mass of the phosphogypsum; the water accounts for 5 to 20 percent of the dry basis mass of the phosphogypsum.
In the method, the stirring speed in the step (3) is 5 to 120r/min.
In the method, the reaction temperature in the step (4) is 120-160 ℃.
In the method, the constant-temperature reaction time in the step (4) is 20 to 120min.
In the method, the drying temperature in the step (5) is 80-130 ℃.
Compared with the prior art, the invention has the beneficial effects that:
the method for preparing the alpha hemihydrate gypsum has the advantages that the flow of preparing the alpha hemihydrate gypsum is simple, the prepared alpha hemihydrate gypsum crystal has good appearance, high structural integrity strength, low water demand in the hydration process and good adaptability, and the alpha ultrahigh strength gypsum with the quality stability exceeding the highest grade of standard JC/T2038-2010 alpha 50 can be prepared under the condition that the phosphogypsum raw material continuously fluctuates; the addition amount of the crystal transformation agent in the preparation process is small, and the cost advantage is achieved; the composite material is easy to popularize and apply in downstream products such as downstream fireproof door core plates, floor heating plates, self-leveling plates, ceramic molds and the like.
Drawings
FIG. 1 is a crystal morphology of alpha hemihydrate gypsum prepared in example 1 of the present invention;
FIG. 2 is a crystal morphology of alpha hemihydrate gypsum prepared in example 1 of the present invention;
fig. 3 is a result of testing alpha hemihydrate gypsum prepared in example 1 of the present invention.
The invention is further illustrated by the following examples, which are not to be construed as limiting the invention.
Detailed Description
Example 1
4Kg of phosphogypsum with the grade of 89.6% is taken, mixed with 1.2% defluorination slag water and washed until the pH value is 5.5, 10.36g of calcium hydroxide, 11.06g of succinic acid, 25.79g of maleic acid, 39.25g of sodium potassium tartrate, 19.96g of sodium citrate and 3.41g of aluminum sulfate are taken, added with 420g of water to prepare a crystal transformation agent solution, the raw materials and the crystal transformation agent are uniformly stirred in a stirrer and then transferred to an autoclave reaction kettle, the reaction temperature is set to be 142 ℃, the stirring speed is 60r/min, the temperature is raised to the reaction temperature, the reaction is kept at constant temperature for 70min, the pressure is released out of the kettle, and the crystal is dried at 100 ℃ to obtain an ultra-high strength gypsum product, the crystal morphology of the product is shown in figures 1 and 2, the initial setting time is 18min, the final setting time is 24min, the bending strength of 2h is 7.2MPa, the compression strength of the drying is 67.8MPa, and the quality inspection result is shown in figure 3.
Example 2
Mixing 4Kg of 85.1% phosphogypsum with 3.0% defluorination residue water, washing until the pH value is 6.5, adding 380g of water into 78.9g of calcium hydroxide, 20.39g of succinic acid, 9.79g of maleic acid, 9.52g of sodium potassium tartrate, 39.01g of sodium citrate and 41.22g of aluminum sulfate to prepare a crystal transformation agent solution, uniformly stirring the raw materials and the crystal transformation agent in a stirrer, transferring the mixture into an autoclave reaction kettle, setting the reaction temperature to be 150 ℃, stirring at the speed of 70r/min, heating to the reaction temperature, reacting at constant temperature for 60min, releasing the pressure of the mixture out of the kettle, drying at 120 ℃ and grinding to obtain an alpha ultrahigh-strength gypsum product, and detecting that the initial setting time is 20min, the final setting time is 25min, the bending strength of 2h is 6.5MPa and the drying compressive strength is 60.4MPa.
Example 3
Mixing 4Kg of phosphogypsum with the grade of 91.3% with 1.9% defluorination slag, washing the mixture until the pH value is 6.1, adding 60.3g of calcium hydroxide, 34.32g of succinic acid, 40.79g of maleic acid, 28.85g of sodium potassium tartrate, 3.15 of sodium citrate and 21.64g of aluminum sulfate into 500g of water to prepare a crystal transformation agent solution, uniformly stirring the raw materials and the crystal transformation agent in a stirrer, transferring the mixture into an autoclave reaction kettle, setting the reaction temperature to 155 ℃, the stirring rate to 48r/min, heating the mixture to the reaction temperature, carrying out constant-temperature reaction for 35min, releasing the pressure in the kettle, drying the mixture at 90 ℃ and grinding the mixture to obtain an alpha ultrahigh-strength gypsum product, wherein the initial setting time is 14min, the final setting time is 18min, the bending strength of 2h is 7.1MPa and the drying compressive strength is 70.3MPa.
Example 4
Mixing 4Kg of phosphogypsum with the grade of 90.3% with 5.0% defluorination residue water, washing until the pH value is 5.7, adding 285g of water into 24.1g of calcium hydroxide, 2.51g of succinic acid, 36.79g of maleic acid, 16.75g of sodium potassium tartrate and 13.65g of sodium citrate to prepare a crystal transformation agent solution, uniformly stirring the raw materials and the crystal transformation agent in a stirrer, transferring the mixture into an autoclave reaction kettle, setting the reaction temperature to 138 ℃, stirring at the speed of 37r/min, heating to the reaction temperature, reacting at constant temperature for 100min, releasing the pressure of the mixture out of the kettle, drying at the temperature of 80 ℃, grinding to obtain an alpha-strength gypsum product, detecting that the initial setting time is 17min, the final setting time is 22min, the bending strength of 2h is 6.9MPa and the drying compressive strength is 58.9MPa.
Example 5
Mixing 4Kg of phosphogypsum with the grade of 87.7% with 4.1% of defluorination slag, washing the mixture until the pH value is 5.9, adding 43.22g of calcium hydroxide, 40.19g of succinic acid, 2.65g of maleic acid, 2.01g of sodium potassium tartrate and 32.17g of sodium citrate into 500g of water to prepare a crystal transformation agent solution, uniformly stirring the raw materials and the crystal transformation agent in a stirrer, transferring the mixture into an autoclave reaction kettle, setting the reaction temperature to be 160 ℃, stirring at the speed of 90r/min, heating to the reaction temperature, reacting at constant temperature for 30min, releasing the mixture out of the kettle, drying at 125 ℃, grinding to obtain an alpha ultrahigh-strength gypsum product, detecting that the initial setting time is 24min, the final setting time is 29min, the bending strength of 2h is 7.5MPa and the drying compressive strength is 78.3MPa.
Comparative example 1
The difference between the comparative example 1 and the example 1 is that the defluorination residue is not mixed in the phosphogypsum washing and purifying process.
The initial setting time of an alpha high-strength gypsum sample obtained by reaction under the condition is 16min, the final setting time is 21min, the bending strength of 2h is 5.6MPa, and the drying compressive strength is 46.3MPa.
Comparative example 2
The difference between the comparative example 2 and the example 2 is that the defluorination residue is not mixed in the phosphogypsum washing and purifying process.
The initial setting time of an alpha high-strength gypsum sample obtained by the reaction under the condition is 18min, the final setting time is 23min, the bending strength of 2h is 4.9MPa, and the drying compressive strength is 38.7MPa.
Comparative example 3
The difference between the comparative example 3 and the example 3 is that 10% defluorinated slag is mixed in the phosphogypsum washing and purifying process.
The initial setting time of an alpha high-strength gypsum sample obtained by reaction under the condition is 62min, the final setting time is 78min, the bending strength of 2h is 3.9MPa, and the drying compressive strength is 28.3MPa.
Claims (8)
1. A method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum is characterized by comprising the following steps:
(1) Phosphogypsum pretreatment and purification: mixing phosphogypsum with defluorination residues, washing and removing impurities;
(2) Preparing a crystal modifier solution: dissolving calcium hydroxide, succinic acid, maleic acid, potassium sodium tartrate, sodium citrate and aluminum sulfate in water to prepare a crystal modifier solution;
(3) Stirring: adding the phosphogypsum purified in the step (1) into the crystal transformation agent solution prepared in the step (2) in a stirrer and uniformly stirring;
(4) Carrying out steam pressure reaction: conveying the phosphogypsum material uniformly stirred in the step (3) and mixed with the crystal transformation agent into an autoclave, sealing, setting the reaction temperature and the stirring speed, heating to the reaction temperature, and reacting at constant temperature for a period of time;
(5) Drying and grinding: after the autoclave reaction is finished, decompressing, discharging from the kettle, drying and grinding to obtain the ultrahigh-strength alpha semi-hydrated gypsum;
the doping amount of the defluorination residues in the step (1) is 1 to 5 percent of the dry basis mass of the phosphogypsum.
2. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum according to claim 1, which is characterized in that: the pH value of the phosphogypsum in the step (1) after washing and purification is 5-6.5.
3. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum according to claim 1, which is characterized in that: the grade of the phosphogypsum raw material in the step (1) is more than or equal to 85 percent.
4. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by using industrial byproduct phosphogypsum according to claim 1, which is characterized by comprising the following steps: the crystal transfer agent solution in the step (2) is prepared according to the following proportion: the mixing amount of the calcium hydroxide is 0.1 to 2 percent of the dry basis mass of the phosphogypsum; the mixing amount of succinic acid is 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the mixing amount of the maleic acid is 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the mixing amount of the potassium sodium tartrate is 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the mixing amount of the sodium citrate is 0.05 to 1 percent of the dry basis mass of the phosphogypsum; the mixing amount of aluminum sulfate is 0 to 1 percent of the dry basis mass of the phosphogypsum; the adding amount of water is 5 to 20 percent of the dry base mass of the phosphogypsum.
5. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum according to claim 1, which is characterized in that: the stirring speed in the step (3) is 5-120r/min.
6. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum according to claim 1, which is characterized in that: the reaction temperature in the step (4) is 120-160 ℃.
7. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by using industrial byproduct phosphogypsum according to claim 1, which is characterized by comprising the following steps: the constant-temperature reaction time in the step (4) is 20 to 120min.
8. The method for preparing ultrahigh-strength alpha hemihydrate gypsum by industrial byproduct phosphogypsum according to claim 1, which is characterized in that: the drying temperature in the step (5) is 80-130 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210627289.4A CN114956624B (en) | 2022-06-06 | 2022-06-06 | Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210627289.4A CN114956624B (en) | 2022-06-06 | 2022-06-06 | Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114956624A CN114956624A (en) | 2022-08-30 |
| CN114956624B true CN114956624B (en) | 2022-11-22 |
Family
ID=82960114
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210627289.4A Active CN114956624B (en) | 2022-06-06 | 2022-06-06 | Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114956624B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115924953B (en) * | 2022-12-21 | 2024-04-19 | 山西中矿石膏规划设计研究院有限公司 | Method for producing ultrahigh-strength gypsum by using waste residue gypsum liquid phase method and gypsum |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1142465A (en) * | 1995-08-10 | 1997-02-12 | 林恒兴 | Cycling use method for removing fluorine dreg in production of phosphates |
| CN102502551A (en) * | 2011-10-20 | 2012-06-20 | 瓮福（集团）有限责任公司 | Method for recycling phosphorus and fluorine in defluorination residues |
| CN102745923A (en) * | 2011-04-22 | 2012-10-24 | 北京建筑材料科学研究总院有限公司 | Process for producing alpha type semi-hydrated gypsum by using industrial by-product gypsum |
| CN103011642A (en) * | 2012-12-19 | 2013-04-03 | 武汉理工大学 | Method for preparing high-strength alpha-type hemihydrate gypsum by utilizing calcium carbide sludge modified phosphogypsum with normal pressure hydrothermal method |
| WO2019100498A1 (en) * | 2017-11-27 | 2019-05-31 | 川恒生态科技有限公司 | Method for producing calcium phosphate salt and high purity gypsum with hydrochloric acid and phosphate rock |
-
2022
- 2022-06-06 CN CN202210627289.4A patent/CN114956624B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1142465A (en) * | 1995-08-10 | 1997-02-12 | 林恒兴 | Cycling use method for removing fluorine dreg in production of phosphates |
| CN102745923A (en) * | 2011-04-22 | 2012-10-24 | 北京建筑材料科学研究总院有限公司 | Process for producing alpha type semi-hydrated gypsum by using industrial by-product gypsum |
| CN102502551A (en) * | 2011-10-20 | 2012-06-20 | 瓮福（集团）有限责任公司 | Method for recycling phosphorus and fluorine in defluorination residues |
| CN103011642A (en) * | 2012-12-19 | 2013-04-03 | 武汉理工大学 | Method for preparing high-strength alpha-type hemihydrate gypsum by utilizing calcium carbide sludge modified phosphogypsum with normal pressure hydrothermal method |
| WO2019100498A1 (en) * | 2017-11-27 | 2019-05-31 | 川恒生态科技有限公司 | Method for producing calcium phosphate salt and high purity gypsum with hydrochloric acid and phosphate rock |
Non-Patent Citations (1)
| Title |
|---|
| 磷石膏制备高强石膏粉预处理工艺的初步研究;周杰等;《广州化工》;20111130(第21期);第75-77页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114956624A (en) | 2022-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100475736C (en) | High-strength waterproof gypsum brick and method for preparing same | |
| CN105174760A (en) | Method for preparing alpha semi-hydrated gypsum from dihydrate gypsum | |
| CN114956624B (en) | Method for preparing ultrahigh-strength alpha hemihydrate gypsum from industrial byproduct phosphogypsum | |
| CN101614051A (en) | Water-tolerant gypsum hollow building block and production method thereof | |
| CN113428887B (en) | Method for preparing alpha high-strength gypsum from industrial byproduct gypsum | |
| CN112939561B (en) | Phosphogypsum-based light plastering gypsum and preparation method thereof | |
| CN113185178B (en) | Phosphogypsum cement retarder and preparation method thereof | |
| CN112479613A (en) | Preparation method for preparing alpha-type high-strength gypsum by self-steaming method | |
| CN111003723B (en) | Method for preparing alpha-semi-hydrated gypsum by using chemical gypsum and alpha-semi-hydrated gypsum prepared by same | |
| CN104030649B (en) | Production process for high-strength high-volume phosphogypsum baking-free brick | |
| CN103011641A (en) | Method for preparing high-activity alpha type hemihydrate gypsum cementing materials by using reaction of chlorine-alkali waste liquid treating ardealite | |
| CN108558343A (en) | A method of preparing assembled high-strength light plank using high strength gypsum slurry | |
| CN106830977B (en) | Production method for non-autoclaved self-insulation lightweight concrete building block | |
| CN108314342B (en) | Method for preparing alpha-type high-strength gypsum from dihydrate phosphogypsum | |
| CN109336442B (en) | Cement early strength agent and use method thereof | |
| CN110550927A (en) | Industrial waste gypsum mortar prepared by industrial tail gas synergy and toxicity solving method | |
| CN115432982B (en) | Preparation method of aerated concrete | |
| CN116606115A (en) | Autoclaved aerated concrete block and preparation method thereof | |
| CN110395961A (en) | It is a kind of to use ECP plate made of gypsum and preparation method thereof | |
| CN116003090A (en) | Autoclaved aerated concrete prepared by full solid waste cooperation and preparation method thereof | |
| CN115636652A (en) | Low-carbon high-strength cementing material taking phosphogypsum as main raw material, preparation method and application thereof | |
| CN115448680A (en) | Low-carbon rapid demoulding prefabricated part prepared from solid waste base cementing material containing cement, fly ash and desulfurized gypsum and preparation method thereof | |
| CN112978780B (en) | Method for purifying phosphogypsum by using aerated concrete steam-pressing condensed water | |
| CN110563426B (en) | Steam-cured high-strength brick prepared from mine salt mud and preparation method thereof | |
| CN114031321B (en) | Process and device for preparing alpha-beta composite semi-hydrated gypsum by using phosphogypsum |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |