CN111470789A - Method for improving utilization efficiency of gypsum in sulphoaluminate cement - Google Patents
Method for improving utilization efficiency of gypsum in sulphoaluminate cement Download PDFInfo
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- CN111470789A CN111470789A CN202010292724.3A CN202010292724A CN111470789A CN 111470789 A CN111470789 A CN 111470789A CN 202010292724 A CN202010292724 A CN 202010292724A CN 111470789 A CN111470789 A CN 111470789A
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- 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
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/38—Preparing or treating the raw materials individually or as batches, e.g. mixing with fuel
- C04B7/42—Active ingredients added before, or during, the burning process
- C04B7/421—Inorganic materials
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- 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
- C04B7/323—Calcium aluminosulfate cements, e.g. cements hydrating into ettringite
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- 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
- C04B7/36—Manufacture of hydraulic cements in general
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- 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
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
- C04B7/44—Burning; Melting
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Abstract
The invention relates to the technical field of novel building material preparation, and discloses a method for improving the utilization efficiency of gypsum in sulphoaluminate cement, which comprises the steps of pretreating the gypsum to improve the activation performance of the gypsum, then respectively preparing sulphoaluminate cement clinker, doping the clinker with the pretreated gypsum, adding the clinker with the gypsum after pretreatment, improving the gel strength and reducing the water demand, promoting the sintering of the sulphoaluminate cement clinker, reducing the combustion temperature and the carbon dioxide yield, improving the hydration activity of calcium sulphoaluminate minerals by using zinc-containing polymetallic nano powder, and not needing to dope a large amount of gypsum, wherein the prepared sulphoaluminate cement has the mixing strength which is 12-17 percent higher than that of 2 times of the added gypsum. The problems of large gypsum consumption and poor accumulation effect in the preparation of the sulphoaluminate cement are solved, the properties of resistance, durability, crack resistance and the like of the sulphoaluminate cement are further improved, and the defect of retrogradation of the later compressive strength of the sulphoaluminate cement is effectively inhibited.
Description
Technical Field
The invention belongs to the technical field of preparation of novel building materials, and particularly relates to a method for improving the utilization efficiency of gypsum in sulphoaluminate cement.
Background
The sulphoaluminate cement is invented by the independent research of Chinese building material science research institute. In 2000 years, the yield of sulphoaluminate cement in China is only 67.25 million tons. By 2005, the yield of sulphoaluminate cement in China reached 125.3 million tons. The enterprises for producing sulphoaluminate cement in China have 30 families, and the national sulphoaluminate cement yield is basically stabilized to about 125 ten thousand tons. The sulphoaluminate cement has the characteristics of early strength, high strength and the like, so that the sulphoaluminate cement is widely applied to the fields of special construction engineering such as hydraulic engineering, rapid repair engineering and the like. Compared with general portland cement, sulphoaluminate cement has the advantages of low alkalinity, high early strength, micro expansion, good erosion resistance and frost resistance, etc., and is one of cement varieties which can compete with portland cement in the future.
Gypsum is one of the important raw materials for producing sulphoaluminate cement, and in the production of the traditional sulphoaluminate cement, about 20 percent of gypsum is required to be added when a raw material is prepared, and 0 to 40 percent of gypsum is required to be added when cement is ground. With the continuous increase of cement yield in China, the demand on gypsum is correspondingly increased, and gypsum resources are continuously reduced; meanwhile, in order to satisfy the balance of gypsum consumption structure, the development and utilization of gypsum resources will be increasingly emphasized. In the prior art, industrial waste phosphogypsum is used to replace natural gypsum, so that the consumption of resources is relieved to a certain extent, but the problems that the use of the phosphogypsum is limited due to unstable cement quality, excessive impurity contents such as phosphorus, fluorine, organic matters and the like exist, the quality of cement is not high, the investment of a modification process is large, the process is complex and the energy consumption is high. Therefore, in order to ensure the sustainable development of the whole gypsum industry, the green, environment-friendly and healthy gypsum building materials and products are more widely applied to people's lives, and limited gypsum resources must be optimized and utilized.
Disclosure of Invention
The invention aims to solve the existing problems and provides a method for improving the utilization efficiency of gypsum in sulphoaluminate cement, which can ensure that the early strength of the sulphoaluminate cement is in a high level and the development of the later strength is continuously and stably, and the cement strength and the durability are high.
The invention is realized by the following technical scheme:
a method for improving the utilization efficiency of gypsum in sulphoaluminate cement comprises the steps of pretreating natural gypsum to improve the activation performance of the natural gypsum, and then respectively using the natural gypsum for the preparation of sulphoaluminate cement clinker and the addition of the clinker. Wherein, zinc-containing multi-metal nano powder and light calcium carbonate are used in the gypsum pretreatment;
further, the preparation method of the zinc-containing multi-metal nano powder additive comprises the following steps: washing zinc ore raw materials with water, drying, grinding and crushing the zinc ore raw materials to be sieved by a 20-30-mesh sieve, adding 7-9 times of sodium hydroxide solution with the concentration of 2.0-2.4 mol/L, heating the mixture to 68-70 ℃ under stirring, continuously stirring the mixture for 30-34 minutes, filtering the mixture while the mixture is hot, standing and aging the obtained filtrate at the temperature of 50-55 ℃ for 12-14 hours, adding 0.36-0.40 times of acetic acid solution with the concentration of 16-20%, dropwise adding tetrabutyl titanate with the mass of 22-26% of the acetic acid solution under stirring, uniformly stirring the mixture at the temperature of 22-25 ℃, dropwise adding 0.60-0.65 times of hydrochloric acid solution with the mol concentration of 1.1-1.2 mol/L into the mixture under stirring, heating the mixture to 45-55 ℃, continuously stirring the mixture for 2-3 hours, placing the mixture in a 68-70 ℃ for 20-24 hours to obtain wet gel with a spatial reticular structure, roasting at 450-500 deg.c for 1.5-2.0 hr, and cooling to normal temperature to obtain the zinc-containing polymetallic nanometer powder additive. The grain size of the zinc-containing multi-metal nano powder additive is between 30 and 45 nanometers. The zinc ore is willemite.
The gypsum pretreatment method comprises the following steps: according to the mass ratio of 180-190: 0.45-0.47: 3.3 to 3.8, mixing the gypsum, the zinc-containing multi-metal nano powder additive and the light calcium carbonate for 2 to 3 hours by a mixer to prepare uniformly mixed inorganic powder, calcining the inorganic powder at the temperature of 300 ℃ to 320 ℃ for 1 to 2 hours, and cooling and quenching the inorganic powder to the temperature of 30 to 35 ℃ at the speed of 18 to 20 ℃/minute.
The fineness of the light calcium carbonate is 800 meshes, and the purity is 98%. The gypsum is dihydrate gypsum or natural anhydrite.
The prepared zinc-containing multi-metal nano powder additive and light calcium carbonate are added into gypsum to obtain a pretreated gypsum product, wherein the strength, stability and waterproof performance of the pretreated gypsum product are superior to those of pure gypsum, the pretreated gypsum product has a large enough specific surface area, and can provide sufficient nucleation sites, so that the hydration process of sulphoaluminate cement is promoted, the crystallinity of a hydration product is improved, the structure development of slurry is more complete, the high setting strength can be shown in a short curing time, and the utilization efficiency of the gypsum in the sulphoaluminate cement is improved.
After the pretreated gypsum is obtained by adopting the scheme, sulphoaluminate cement clinker is further prepared;
the sulphoaluminate cement raw meal comprises the following main components in percentage by mass: 48-54% of limestone, 27-33% of bauxite, 4.5-5.5% of pretreated gypsum and the balance of aluminium ash and small amount of impurities. The adopted limestone is obtained from a south Henan Yang limestone factory; bauxite and aluminum ash are obtained from Guiyang city Fangcheng mining Co.
Preparation of sulphoaluminate cement clinker: and grinding the proportioned raw materials into powder, sieving the powder to 70-80 micron sieves, heating and calcining, wherein the firing process temperature of the clinker is 1090-one and 1100 ℃, keeping the temperature and firing for 20-25 minutes, and cooling to obtain the sulphoaluminate cement clinker.
Preferably, the addition amount of the pretreated gypsum in the sulphoaluminate cement raw material accounts for 4.8-5.3%, and the amount of the pretreated gypsum doped after the cement clinker is prepared is 0.8-1.0%.
In the preparation process of the sulphoaluminate cement, the additive used in the gypsum pretreatment plays a role in promoting hydration reaction, so that the addition of a small amount of gypsum can also improve the performance of the cement, the hydration reaction speed is improved, the structure of the mixed slurry can be refined, and a more compact structural form is generated. The prepared sulphoaluminate cement has the compression strength of 75-78MPa in 28 days and the breaking strength of 14-16.0MPa, and effectively inhibits the later-stage compression strength collapse defect of the sulphoaluminate cement.
The invention gives full play to the economic value of the gypsum, improves the performance of preparing the sulphoaluminate cement by the gypsum and reduces the using and adding amount of the gypsum. The addition of the pretreated gypsum not only improves the gel strength and reduces the water demand, but also promotes the firing of the sulphoaluminate cement clinker, reduces the combustion temperature and the carbon dioxide output, improves the hydration activity of the calcium sulphoaluminate minerals by utilizing the zinc-containing multi-metal nano powder, does not need to mix a large amount of gypsum, and improves the mixing ratio strength of the prepared sulphoaluminate cement by 12 to 17 percent compared with the addition ratio strength of 2 times of the gypsum. The problems of large gypsum consumption and poor accumulation effect in the preparation of the sulphoaluminate cement are solved, the performances of resistance, durability, crack resistance and the like of the sulphoaluminate cement are further improved, the pollution of the sulphoaluminate cement production to the environment is reduced, and the development requirement of the modern novel building material industry is met.
Compared with the prior art, the invention has the following advantages: in order to solve the problem that the resource utilization rate of natural gypsum in sulphoaluminate cement is not high, the invention provides a method for improving the utilization efficiency of gypsum in sulphoaluminate cement, the pretreated gypsum is added and used, the effects of improving the gel strength and reducing the water demand are achieved, the firing of sulphoaluminate cement clinker is promoted, the combustion temperature and the carbon dioxide yield are reduced, the hydration activity of calcium sulphoaluminate minerals is improved by utilizing zinc-containing polymetallic nano powder, a large amount of gypsum does not need to be doped later, and the prepared sulphoaluminate cement has the mixing ratio strength which is 12-17 percent higher than that of 2 times of the added gypsum. The problems of large gypsum consumption and poor accumulation effect in the preparation of the sulphoaluminate cement are solved, the properties of resistance, durability, crack resistance and the like of the sulphoaluminate cement are further improved, the 28-day compressive strength of the prepared sulphoaluminate cement reaches 75-78MPa, the flexural strength reaches 14-16.0MPa, and the defect of backward shrinkage of the later-stage compressive strength of the sulphoaluminate cement is effectively inhibited. The invention effectively overcomes the adverse effect of adopting industrial waste phosphogypsum to replace natural gypsum in the prior art, has good compatibility with cement components, can prepare high-grade cement, greatly reduces the gypsum dosage under the condition of ensuring the performance of the sulphoaluminate cement, has the characteristics of low cost, low energy consumption and high performance, greatly reduces the waste of resources, reduces the pollution of the sulphoaluminate cement production to the environment, meets the development requirement of modern novel building material industry, can realize the practical significance of improving the overall utilization rate of the sulphoaluminate cement in the new building material industry and the market competitiveness, has higher value for improving the gypsum utilization rate and the research on the production process of the sulphoaluminate cement, obviously promotes the diversified rapid development and the sustainable development of the building material industry, is a technical scheme which is very worthy of popularization and application.
Detailed Description
In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described with reference to specific embodiments, and it should be understood that the specific embodiments described herein are only used for explaining the present invention and are not used for limiting the technical solutions provided by the present invention.
Example 1
A method for improving the utilization efficiency of gypsum in sulphoaluminate cement comprises the steps of pretreating natural gypsum to improve the activation performance of the natural gypsum, and then respectively using the natural gypsum for the preparation of sulphoaluminate cement clinker and the addition of the clinker.
Specifically, the preparation of the sulphoaluminate cement clinker: and grinding the proportioned raw materials into powder, sieving the powder to a sieve of 70 microns, heating and calcining, keeping the firing process temperature of the clinker at 1090 ℃ for 20-25 minutes, and cooling to obtain the sulphoaluminate cement clinker.
The sulphoaluminate cement raw material comprises the following main components in percentage by mass: 48 percent of limestone, 27 percent of bauxite and 4.5 percent of pretreated gypsum, and the balance is aluminum ash and a small amount of impurities.
The adopted limestone is obtained from a south Henan Yang limestone factory; bauxite and aluminum ash are obtained from Guiyang city Fangcheng mining Co.
The preparation method of the pretreated gypsum comprises the following steps: according to the mass ratio of 180: 0.45: 3.3 mixing the gypsum, the zinc-containing multi-metal nano powder additive and the light calcium carbonate for 2 hours by a mixer to prepare uniformly mixed inorganic powder, calcining the powder for 1 hour at 300 ℃, and cooling and quenching the powder to 30 ℃ at the speed of 18 ℃/minute.
Furthermore, the fineness of the light calcium carbonate is 800 meshes, and the purity is 98%. The gypsum is dihydrate gypsum or natural anhydrite.
Further, the preparation method of the zinc-containing multi-metal nano powder additive comprises the following steps: washing a zinc ore raw material with water, drying, grinding and crushing the zinc ore raw material to pass through a 20-mesh sieve, adding 7 times of sodium hydroxide solution with the volume of 2.0 mol/L, heating to 68 ℃ under stirring, continuously stirring for 30 minutes, filtering while the zinc ore raw material is hot, standing and aging the obtained filtrate at 50 ℃ for 12 hours, adding 0.36 times of acetic acid solution with the volume of 16 percent, dropwise adding tetrabutyl titanate with the mass of 22 percent of the acetic acid solution under stirring, uniformly stirring at 22 ℃, dropwise adding 0.60 times of hydrochloric acid solution with the volume of 1.1 mol/L into the mixture under stirring, heating to 45 ℃, continuously stirring for 2 hours, placing the mixture in a 68 ℃ oven for 20 hours to obtain wet gel with a three-dimensional space net-shaped structure, roasting at 450 ℃ for 1.5 hours, and cooling to normal temperature to obtain the zinc-containing polymetallic nanopowder additive. The grain size of the zinc-containing multi-metal nano powder additive is between 30 and 45 nanometers. The zinc ore is willemite.
More preferably, the amount of the gypsum pre-treated after the cement clinker is prepared is 0.8 percent.
Example 2
A method for improving the utilization efficiency of gypsum in sulphoaluminate cement comprises the steps of pretreating natural gypsum to improve the activation performance of the natural gypsum, and then respectively using the natural gypsum for the preparation of sulphoaluminate cement clinker and the addition of the clinker.
Specifically, the preparation of the sulphoaluminate cement clinker: and grinding the proportioned raw materials into powder, sieving the powder to 75-micron sieves, heating and calcining, keeping the firing process temperature of the clinker at 1095 ℃ for 22 minutes, and cooling to obtain the sulphoaluminate cement clinker.
The sulphoaluminate cement raw material comprises the following main components in percentage by mass: 51% of limestone, 30% of bauxite, 5.0% of pretreated gypsum and the balance of aluminum ash and a small amount of impurities.
The adopted limestone is obtained from a south Henan Yang limestone factory; bauxite and aluminum ash are obtained from Guiyang city Fangcheng mining Co.
The preparation method of the pretreated gypsum comprises the following steps: according to the mass ratio of 185: 0.46: 3.5, mixing the gypsum, the zinc-containing multi-metal nano powder additive and the light calcium carbonate for 2.5 hours by a mixer to prepare uniformly mixed inorganic powder, calcining the inorganic powder at 310 ℃ for 1.5 hours, and cooling and quenching the inorganic powder to 32 ℃ at the speed of 19 ℃/minute.
Furthermore, the fineness of the light calcium carbonate is 800 meshes, and the purity is 98%. The gypsum is dihydrate gypsum or natural anhydrite.
Further, the preparation method of the zinc-containing multi-metal nano powder additive comprises the following steps: washing a zinc ore raw material with water, drying, grinding and crushing the zinc ore raw material to be sieved by a 25-mesh sieve, adding 8 times of sodium hydroxide solution with the volume concentration of 2.2 mol/L, heating to 69 ℃ under stirring, continuously stirring for 32 minutes, filtering while the zinc ore raw material is hot, standing and aging the obtained filtrate at 52 ℃ for 13 hours, adding 0.38 times of acetic acid solution with the volume concentration of 18 percent, dropwise adding tetrabutyl titanate with the mass of 24 percent of the acetic acid solution under stirring, uniformly stirring at 23 ℃, dropwise adding 0.62 times of hydrochloric acid solution with the volume concentration of 1.15 mol/L into the mixture under stirring, heating to 50 ℃, continuously stirring for 2.5 hours, placing the mixture in a 69 ℃ oven for 22 hours to obtain wet gel with a three-dimensional space net-shaped structure, roasting at 480 ℃ for 1.8 hours, and cooling to normal temperature to obtain the zinc-containing polymetallic nano metal powder additive. The grain size of the zinc-containing multi-metal nano powder additive is between 30 and 45 nanometers. The zinc ore is willemite.
More preferably, the amount of the gypsum pre-treated after the cement clinker is prepared is 0.9 percent.
Example 3
A method for improving the utilization efficiency of gypsum in sulphoaluminate cement comprises the steps of pretreating natural gypsum to improve the activation performance of the natural gypsum, and then respectively using the natural gypsum for the preparation of sulphoaluminate cement clinker and the addition of the clinker.
Specifically, the preparation of the sulphoaluminate cement clinker: and grinding the proportioned raw materials into powder, sieving the powder to 80-micron sieves, heating and calcining, keeping the firing process temperature of the clinker at 1100 ℃, firing for 25 minutes, and cooling to obtain the sulphoaluminate cement clinker.
The sulphoaluminate cement raw material comprises the following main components in percentage by mass: 54 percent of limestone, 33 percent of bauxite and 5.5 percent of pretreated gypsum, and the balance is aluminum ash and a small amount of impurities.
The adopted limestone is obtained from a south Henan Yang limestone factory; bauxite and aluminum ash are obtained from Guiyang city Fangcheng mining Co.
The preparation method of the pretreated gypsum comprises the following steps: according to the mass ratio of 190: 0.47: 3.8 mixing the gypsum, the zinc-containing multi-metal nano powder additive and the light calcium carbonate for 2-3 hours by a mixer to prepare uniformly mixed inorganic powder, calcining the inorganic powder at 320 ℃ for 2 hours, and cooling and quenching the inorganic powder to 35 ℃ at the speed of 20 ℃/minute.
Furthermore, the fineness of the light calcium carbonate is 800 meshes, and the purity is 98%. The gypsum is dihydrate gypsum or natural anhydrite.
Further, the preparation method of the zinc-containing multi-metal nano powder additive comprises the following steps: washing a zinc ore raw material with water, drying, grinding and crushing the zinc ore raw material to be sieved by a 30-mesh sieve, adding 9 times of sodium hydroxide solution with the volume concentration of 2.4 mol/L, heating to 70 ℃ under stirring, continuously stirring for 34 minutes, filtering while the zinc ore raw material is hot, standing and aging the obtained filtrate at 55 ℃ for 14 hours, adding 0.40 times of acetic acid solution with the volume concentration of 20 percent, dropwise adding tetrabutyl titanate with the mass of the acetic acid solution of 26 percent under stirring, uniformly stirring at 25 ℃, dropwise adding 0.65 times of hydrochloric acid solution with the volume concentration of 1.2 mol/L into the mixture under stirring, heating to 55 ℃, continuously stirring for 3 hours, placing the mixture in a 70 ℃ oven for 24 hours to obtain wet gel with a three-dimensional space net-shaped structure, roasting at 500 ℃ for 2.0 hours, and cooling to normal temperature to obtain the zinc-containing polymetallic nano powder additive. The grain size of the zinc-containing multi-metal nano powder additive is between 30 and 45 nanometers. The zinc ore is willemite.
More preferably, the amount of the gypsum pre-treated after the cement clinker is prepared is 1.0%.
Example 4
The difference from the example 3 is only that the addition amount of the pre-treated gypsum in the sulphoaluminate cement raw meal is 4.0 percent, and the addition amount of the post-mixed pre-treated gypsum in the prepared cement clinker is 0.5 percent; the rest remained unchanged.
Example 5
The difference from the example 3 is only that the addition amount of the pre-treated gypsum in the sulphoaluminate cement raw meal is 6.0 percent, and the amount of the post-doped pre-treated gypsum in the prepared cement clinker is 1.5 percent; the rest remained unchanged.
Comparative example 1
The same amount of nano calcium carbonate powder was used to replace the zinc-containing multi-metal nano powder additive of example 3, and the rest remained unchanged.
Comparative example 2
The zinc-containing multi-metal nanopowder additive of example 3 was replaced with an equal amount of nanosilica powder, the rest remaining unchanged.
First, performance experiment
The method of the embodiment 1-5 and the comparative example 1-2 is used for improving the utilization efficiency of gypsum in the production of sulphoaluminate cement, meanwhile, the existing method of mixing phosphogypsum into sulphoaluminate cement according to the mass ratio of 3:8 is used as a reference, the water cement ratio is 0.48, cement products prepared by each group are compared, the cement slurry prepared by each group is processed into a sample module with the size of 40 mm × 40 mm, × 40 mm, the sample module is placed into a constant-temperature and constant-humidity curing box for curing, the strength performance, the mechanical performance, the durability and the like are tested after the corresponding age (3 d, 7d and 28 d) is reached, irrelevant variables are kept consistent in the test, the result statistical analysis is carried out (the test design is carried out by using a statistical method before the test, then the test is carried out, test data are recorded, the test result is obtained by analysis, and the statistical tool is fully used for explaining the result to the greatest extent in the process)
(Note: test standards GB/T20472 & lt 2006 & gt sulphoaluminate Cement & gt, GB/T17671 & lt 1999 & gt Cement mortar Strength test method (ISO); and DKZ-5000 electric bending resistance tester and WE-600B universal tester are adopted to measure the bending strength and the compressive strength of the cement test block at 3d, 7d and 28d of coagulation.)
Secondly, the experimental result is as follows:
the average initial setting time of examples 1-3 was extended by 2.5-3.0 minutes from the average of comparative examples 1-2; the average level of final setting time is shortened by 3.5-4.0 minutes compared with the average level of the comparative example 1-2;
therefore, the sulphoaluminate cement obtained by the treatment of the method has the best comprehensive performance, and the utilization rate of gypsum is obviously improved.
The invention improves the comprehensive utilization rate of natural gypsum, reduces the complex doping of other auxiliary additive materials, reduces the cost, effectively overcomes the adverse effect of adopting industrial waste phosphogypsum to replace the natural gypsum in the prior art, has good compatibility with cement components, can prepare high-grade cement, greatly reduces the gypsum dosage under the condition of ensuring the performance of the sulphoaluminate cement, has the characteristics of low cost, low energy consumption and high performance, greatly reduces the waste of resources, reduces the pollution of the sulphoaluminate cement production to the environment, meets the development requirement of the modern novel building material industry, can realize the practical significance of improving the overall utilization rate of the sulphoaluminate cement in the new building material industry and the market competitiveness, has higher value for improving the gypsum utilization rate and the research of the sulphoaluminate cement production process method, obviously promotes the diversified rapid development and the sustainable development of the building material industry, is a technical scheme which is very worthy of popularization and application.
Claims (7)
1. A method for improving the utilization efficiency of gypsum in sulphoaluminate cement is characterized in that the gypsum is pretreated to improve the activation performance of the gypsum, and then the gypsum is respectively used for preparing sulphoaluminate cement clinker and adding the clinker; the gypsum pretreatment method comprises the following steps: according to the mass ratio of 180-190: 0.45-0.47: 3.3 to 3.8, mixing the gypsum, the zinc-containing multi-metal nano powder additive and the light calcium carbonate for 2 to 3 hours by a mixer to prepare uniformly mixed inorganic powder, calcining the inorganic powder at the temperature of 300 ℃ to 320 ℃ for 1 to 2 hours, and cooling and quenching the inorganic powder to 30 to 35 ℃ at the speed of 18 to 20 ℃/minute; the preparation method of the zinc-containing multi-metal nano powder comprises the following steps:
(1) washing zinc ore raw materials, drying, grinding and crushing the zinc ore raw materials to 20-30 meshes, adding 7-9 times of sodium hydroxide solution with the concentration of 2.0-2.4 mol/L, heating to 68-70 ℃ under stirring, continuously stirring for 30-34 minutes, filtering while hot, standing and aging the obtained filtrate for 12-14 hours at 50-55 ℃, and adding 0.36-0.40 times of acetic acid solution with the concentration of 16-20% by volume;
(2) dropwise adding tetrabutyl titanate with the mass of 22-26% of that of the acetic acid solution under stirring, uniformly stirring at 22-25 ℃, then dropwise adding 0.60-0.65 volume times of hydrochloric acid solution with the molar concentration of 1.1-1.2 mol/L into the mixture under stirring, heating to 45-55 ℃, continuously stirring for 2-3 hours, placing in a 68-70 ℃ oven for 20-24 hours to obtain wet gel, roasting at 450-500 ℃ for 1.5-2.0 hours, and cooling to normal temperature to obtain the zinc-containing polymetallic nanopowder additive.
2. The method of claim 1, wherein the gypsum is dihydrate gypsum or natural anhydrite.
3. The method of claim 1, wherein the light calcium carbonate has a fineness of 800 mesh and a purity of 98%.
4. The method for improving the utilization efficiency of gypsum in sulphoaluminate cement as claimed in claim 1, wherein the sulphoaluminate cement raw meal comprises the following main components in percentage by mass: 48-54% of limestone, 27-33% of bauxite, 4.5-5.5% of pretreated gypsum and the balance of aluminium ash and small amount of impurities.
5. The method of claim 1, wherein the pre-treated gypsum is added in an amount of 4.8-5.3% to the raw material of the sulphoaluminate cement, and the amount of pre-treated gypsum added after the production of the cement clinker is 0.8-1.0%.
6. The method of claim 1, wherein the preparation of the sulphoaluminate cement clinker: and grinding the proportioned raw materials into powder, sieving the powder to 70-80 micron sieves, heating and calcining, wherein the firing process temperature of the clinker is 1090-one and 1100 ℃, keeping the temperature and firing for 20-25 minutes, and cooling to obtain the sulphoaluminate cement clinker.
7. The method of claim 1, wherein the zinc-containing multi-metal nanopowder additive has a particle size of between 30-45 nanometers and the zinc ore used for the preparation is willemite.
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| CN112028507A (en) * | 2020-09-17 | 2020-12-04 | 淄博云鹤彩色水泥有限公司 | Leaking stoppage waterproofing agent prepared from waste and preparation method thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112028507A (en) * | 2020-09-17 | 2020-12-04 | 淄博云鹤彩色水泥有限公司 | Leaking stoppage waterproofing agent prepared from waste and preparation method thereof |
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Application publication date: 20200731 |