CN115403285A - Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature - Google Patents
Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature Download PDFInfo
- Publication number
- CN115403285A CN115403285A CN202210853902.4A CN202210853902A CN115403285A CN 115403285 A CN115403285 A CN 115403285A CN 202210853902 A CN202210853902 A CN 202210853902A CN 115403285 A CN115403285 A CN 115403285A
- Authority
- CN
- China
- Prior art keywords
- phosphogypsum
- sulphoaluminate cement
- carbon emission
- cement
- reduction method
- 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.)
- Pending
Links
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
- C04B7/00—Hydraulic cements
- C04B7/32—Aluminous cements
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Catalysts (AREA)
Abstract
The invention relates to a carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature, belonging to the technical field of cement. The specific formula and the flow are as follows: ardealite is used to replace limestone and natural gypsum, and is mixed with alumina, silica, catalyst and reductant, and the mixture is ground to 500 deg.c o C~900 o C low temperature decomposition, 1250 o C~1300 o And C, calcining to prepare the sulphoaluminate cement. The method realizes the low-temperature decomposition and utilization of the phosphogypsum and avoids using limestone and natural gypsum.
Description
Technical Field
The invention relates to a carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature, belonging to the technical field of cement.
Background
Phosphogypsum is a byproduct generated in the process of producing phosphoric acid by a wet method, and the main component of phosphogypsum is CaSO 4 ·2H 2 O, per systemAbout 4-5 tons of phosphogypsum are produced by taking 1 ton of phosphoric acid. As the first major phosphate fertilizer producing country in China, the accumulated phosphogypsum is over 7 hundred million tons, the annual emission amount is up to 8000 million tons, and the utilization rate is less than 40 percent. The large amount of stockpiling of the phosphogypsum not only restricts the development of phosphorus chemical enterprises, but also seriously influences the ecological environment.
With the implementation of the double-carbon strategy in China, green and low carbon become the main melody of energy development. Facing the industry mainly comprising manufacturing industry, the effective path for realizing 'carbon peaking and carbon neutralization' is to reduce the energy consumption and carbon emission in the production process. The sulphoaluminate cement is prepared by using gypsum, limestone and alumina as raw materials, calcining the raw materials to obtain cement clinker taking calcium sulphoaluminate and dicalcium silicate as main minerals, and mixing and grinding the cement clinker with a proper amount of gypsum. The sulphoaluminate cement has the advantages of low alkalinity, high early strength, micro expansion, corrosion resistance, frost resistance and the like, and is widely applied to various fields of building material industry. Therefore, how to prepare the sulphoaluminate cement by using the phosphogypsum on the premise of reducing the carbon emission becomes a hot focus of researchers at home and abroad.
The invention patent CN103304170A discloses a method for producing sulphoaluminate cement, the raw mix proportion is limestone 30-60 parts, phosphogypsum 25-55 parts, low grade alumina 15-45 parts, the cement raw mix prepared is calcined under high temperature after being ground evenly, the waste phosphogypsum can be successfully used to replace natural gypsum, the cost of cement is properly reduced.
The invention patent CN106431030B discloses a method for preparing sulphoaluminate cement from phosphogypsum, which comprises the steps of preparing phosphogypsum, bauxite, solid waste steel slag and anthracite into cement raw material according to a certain proportion, grinding and uniformly mixing the raw material, and then performing 1250-step grinding o C~1300 o Calcining at the temperature of C, wherein calcium sulfate in the phosphogypsum is reduced by anthracite coal in the calcining process to generate sulfur dioxide and calcium oxide, the calcium oxide generated by decomposition completely replaces limestone, sulfur dioxide gas can be collected to prepare sulfuric acid, the decomposition rate of the phosphogypsum reaches 70-85%, and the utilization rate of the phosphogypsum is greatly improved.
The invention patent CN108892401B discloses a method for preparing belite sulphoaluminate cement clinker by calcining phosphogypsumThe method comprises the following main steps: firstly weighing 75-80 parts of phosphogypsum, 10-15 parts of aluminum raw material and 10-15 parts of silicon raw material, mixing and grinding to obtain cement raw material; then the cement raw material is placed at 1000 deg.C o C ~1100 o Desulfurizing at C for 160-180 min, and then at 1320- o C ~1350 o Calcining at the temperature of C for 60-80 minutes until the clinker minerals are completely formed. In the burdening process, limestone is not used, impurities in the phosphogypsum are used as a mineralizing agent, and the phosphogypsum is maximally utilized through a special calcination system.
The prior method for preparing the sulphoaluminate cement by using the phosphogypsum generally has the problems of higher phosphogypsum decomposition temperature, complex process flow, higher production cost and energy consumption and the like. Therefore, on the basis of reducing the phosphogypsum decomposition temperature, the operation steps are simplified, the production cost is reduced, the phosphogypsum consumption is increased, the environmental pollution is reduced, and an effective path is provided for realizing the resource utilization of the phosphogypsum.
Disclosure of Invention
The invention provides a method for producing sulphoaluminate cement by using phosphogypsum to completely replace limestone and natural gypsum, improve the utilization rate of the phosphogypsum and reduce carbon emission, and has the advantages of simple process route, low production cost and good economic and environmental benefits.
The technical scheme of the invention is as follows:
a carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature comprises the following steps:
the preparation method comprises the following steps of mixing 55-70 parts by mass of phosphogypsum, 15-20 parts by mass of alumina, 0.1-0.5 part by mass of silicon dioxide, 4-18 parts by mass of catalyst and 5-13 parts by mass of reducing agent, grinding, decomposing at low temperature and 1250 o C~1300 o Calcining the C for 0.5 to 2.0 hours, naturally cooling, and grinding to obtain the sulphoaluminate cement.
The catalyst is at least one of ferric chloride, cobalt chloride and nickel chloride, and the dosage of the catalyst is equal to that of CaSO in phosphogypsum 4 The molar ratio of (b) is 0.05 to 0.2.
The reducing agent is coke with carbon content of 80 to 87 percent, and the using amount of the cokeWith CaSO in phosphogypsum 4 The molar ratio of (A) to (B) is 0.5 to 3.5.
The calcination systems of the low-temperature decomposition stages of the phosphogypsum are respectively 500 o C ~900 o Keeping the temperature at the temperature of C for 0.5 to 2.0 hours.
The invention uses the phosphogypsum to completely replace limestone and natural gypsum to prepare the sulphoaluminate cement, reduces the carbon emission, and the phosphogypsum is used as both a calcareous raw material and a sulphurous raw material. In the process of calcining the cement raw material, most phosphogypsum is decomposed under the double action of a catalyst and a reducing agent, calcium oxide, silicon dioxide, aluminum oxide and unreduced calcium sulfate which are generated by decomposition are sintered at high temperature to form cement clinker minerals calcium sulphoaluminate and dicalcium silicate, and the residual undecomposed phosphogypsum is converted into high-temperature gypsum after high-temperature calcination and can replace natural gypsum which is required by a clinker product and is added externally, so that the sulphoaluminate cement is finally prepared.
The invention has the following advantages:
1. the invention utilizes the phosphogypsum to completely replace limestone and natural gypsum to prepare the sulphoaluminate cement, thereby not only reducing the production cost of the sulphoaluminate cement, realizing the resource utilization of the phosphogypsum, but also effectively reducing the carbon emission and the pollution to the environment.
2. When the raw material is prepared, metal ions and coke are added to promote the phosphogypsum to be subjected to reductive decomposition, one part of the undecomposed phosphogypsum is taken as a sulfate component for forming cement clinker minerals, and the other part of the undecomposed phosphogypsum can replace natural gypsum doped in the cement clinker, so that the sulphoaluminate cement can be directly prepared.
3. In the invention, a calcining mode of decomposing phosphogypsum at low temperature is adopted, and is 500 o C~900 o And C, preserving the heat for 0.5 to 2.0 hours, promoting the calcium sulfate in the phosphogypsum to be decomposed into calcium oxide, and facilitating the formation of sulphoaluminate cement clinker minerals.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but the present invention is not limited to these examples.
Mixing phosphogypsum, alumina, silicon dioxide, reducing agent and catalyst, and grinding into fine powderThe cement is 100 meshes, and is made into blocks of 40-20-20mm after being mixed with water, so as to obtain the cement raw material. The addition amounts of phosphogypsum, alumina, silica, reducing agent and catalyst, as well as the low temperature decomposition temperature and the holding time are shown in table 1. Drying the prepared cement raw material, and raising the temperature to 500 ℃ according to the program o C~900 o C, keeping the temperature for 0.5 to 2.0 hours at 1250 o C~1300 o C, preserving the heat for 0.5 to 2.0 hours, and naturally cooling to obtain the sulphoaluminate cement clinker. The fired cement clinker was reground to 350 m 2 And/kg, thus obtaining the sulphoaluminate cement.
TABLE 1 proportioning and decomposition temperature of sulphoaluminate cement raw materials
From the examples 1 to 10, it can be seen that the 28d compressive strength of the sulphoaluminate cement prepared by the method is greater than 45 MPa, and the mechanical properties of the sulphoaluminate cement meet the standard of sulphoaluminate cement in GB 20472-2006.
Claims (4)
1. A carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature comprises the following steps:
mixing 55-70 parts of phosphogypsum, 15-20 parts of alumina, 0.1-0.5 part of silicon dioxide, 4-18 parts of catalyst and 5-13 parts of reducing agent according to the mass parts, mixing, grinding, decomposing at low temperature and 1250 o C~1300 o Calcining the C for 0.5 to 2.0 hours, naturally cooling, and grinding to obtain the sulphoaluminate cement.
2. The carbon emission reduction method for preparing sulphoaluminate cement through phosphogypsum low-temperature decomposition according to claim 1, wherein the catalyst is at least one of ferric chloride, cobalt chloride and nickel chloride.
3. The carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature according to claim 1, wherein the reducing agent is coke and CO.
4. The carbon emission reduction method for preparing sulphoaluminate cement by phosphogypsum low-temperature decomposition according to claim 1, wherein the low-temperature decomposition temperature of phosphogypsum is 500 o C~900 o And C, the calcining time is 0.5 to 2.0 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210853902.4A CN115403285A (en) | 2022-07-20 | 2022-07-20 | Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210853902.4A CN115403285A (en) | 2022-07-20 | 2022-07-20 | Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115403285A true CN115403285A (en) | 2022-11-29 |
Family
ID=84157600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210853902.4A Pending CN115403285A (en) | 2022-07-20 | 2022-07-20 | Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115403285A (en) |
-
2022
- 2022-07-20 CN CN202210853902.4A patent/CN115403285A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103304170B (en) | Method for producing sulphate aluminum cement | |
| CN111393047B (en) | High-iron belite cement and preparation method thereof | |
| CN101003422B (en) | New method for producing sulfuric acid and cement by using phosphogypsum | |
| CN108821686B (en) | Preparation method of aluminum calcium carbonate composite cementing material and product | |
| CN111635152B (en) | High belite sulphoaluminate cement clinker and preparation method thereof | |
| CN101423355A (en) | Sulphoaluminates expansion agent prepared by industrial residue used in cement or concrete | |
| CN102765893B (en) | Method for preparing sulphoaluminate special cement clinker from waste residue fluorine gypsum and red mud | |
| CN115286266B (en) | Carbon-negative clinker prepared from phosphogypsum and preparation method of carbon-negative clinker | |
| CN101885589A (en) | Compound sulfate cement | |
| CN113354311A (en) | Resource-saving low-carbon cement clinker and preparation method thereof | |
| CN110963721A (en) | Method for producing active admixture by utilizing dry-process cement plant transformation treatment manganese slag | |
| CN112624640A (en) | Full-solid waste sulphoaluminate cement clinker for prefabricated parts and preparation method thereof | |
| CN111847956A (en) | Phosphogypsum-based cement retarder and preparation method and application thereof | |
| CN112028506B (en) | Method and system for co-production of sulphoaluminate-potassium magnesium phosphate composite gel material and sulphur | |
| CN106630703A (en) | Method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps | |
| CN103896554A (en) | Autoclaved brisk taking dolomite tailings and iron tailings as main raw materials and preparation method thereof | |
| CN104761160A (en) | Modified slag powder and preparation method thereof | |
| CN1696073A (en) | Method for producing sulfuric acid associated with high Belite cement through anhydrite | |
| CN1092747A (en) | High-efficiency concrete expansion admixture and manufacture method thereof | |
| CN108585575B (en) | Cement retarder and preparation method and application thereof | |
| CN115650609A (en) | Carbon-cured cementing material, preparation method and application | |
| CN115403285A (en) | Carbon emission reduction method for preparing sulphoaluminate cement by decomposing phosphogypsum at low temperature | |
| CN116282988B (en) | Method for preparing low-calcium solid carbon gel material by using phosphogypsum | |
| CN115304296B (en) | Recyclable cement and preparation method thereof | |
| CN113354315B (en) | Method for producing high-silicon sulphoaluminate cement by using phosphorus acid insoluble slag |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |