阅读说明：本技术 一种单组分地聚物水泥制备方法 (Preparation method of single-component geopolymer cement ) 是由 张会芝 刘纪峰 杨悦 陈孝国 连跃宗 付晓强 于 2020-05-15 设计创作，主要内容包括：本发明提供一种单组分地聚物水泥制备方法。本发明利用金属尾矿、长石、造纸白泥和水泥窑粉等主要成分为SiO<Sub>2</Sub>、Al<Sub>2</Sub>O<Sub>3</Sub>和含Ca化合物的工业副产品,通过加入固体碱激发剂制备单组分地聚物水泥。一方面减少了金属尾矿堆存带来的环境压力,另一方面由于原料来源广,价格低廉,能实现金属尾矿等固体废弃物的资源化利用。该单组分地聚物水泥的28d立方体抗压强度为35～45MPa,可广泛应用于混凝土制备、岩土体灌浆加固、公路或机场跑道快速修复、混凝土预制构件制作、墙体砌块制作以及透水路面砖和路缘石等建材产品的生产原材料。(The invention provides a preparation method of single-component geopolymer cement. The invention utilizes metal tailings, feldspar, papermaking white mud, cement kiln powder and the like as the main components of SiO 2 、Al 2 O 3 And industrial by-products of Ca-containing compounds, by adding a solid alkali activator. On one hand, the environmental pressure caused by the stockpiling of the metal tailings is reduced, and on the other hand, the resource utilization of the metal tailings and other solid wastes can be realized due to wide raw material sources and low price. The single-component geopolymer cement has the 28d cubic compressive strength of 35-45 MPa, and can be widely applied to production raw materials of building material products such as concrete preparation, rock and soil mass grouting reinforcement, rapid repair of highways or airport runways, concrete prefabricated part manufacturing, wall building block manufacturing, permeable pavement bricks, kerbs and the like.)

1. A method for preparing single-component geopolymer cement, characterized by comprising the following steps:

s1, obtaining raw materials, and respectively counting SiO in the raw materials₂、Al₂O₃And the content of Ca-containing compounds is obtained to obtain an analysis result, wherein the Ca-containing compounds are CaO and/or CaCO₃The raw material is selected from one or more of metal tailings, papermaking white mud, feldspar and cement kiln dust;

s2, blending the raw materials to obtain an admixture according to the analysis result;

s3, adding Na into the admixture₂CO₃Uniformly mixing, calcining, and immediately cooling the calcined molten material to obtain a calcined product;

and S4, grinding the calcined product to obtain the single-component geopolymer cement.

2. The method for preparing single-component geopolymer cement according to claim 1, wherein in step S1, the SiO is in the metal tailings according to mass percentage₂35 to 45 percent of Al₂O₃5% -8% of the white mud, 25% -30% of CaO, and SiO in the white mud₂1 to 3 percent of Al₂O₃0.2-0.8% of CaO, 45-55% of CaO, in the feldspar, the SiO₂65% -80% of Al₂O₃13% -15%, CaO 1% -3%, and in the cement kiln dust, SiO₂6 to 8 percent of Al₂O₃2 to 3 percent of CaO and 45 to 60 percent of CaO.

3. The method for preparing single-component geopolymer cement according to claim 1, wherein in step S2, the SiO is contained in the admixture by mass percentage₂30 to 45 percent of the Al₂O₃6 to 15 percent of the CaO, and 30 to 40 percent of the CaO, wherein the SiO is₂And said Al₂O₃The mass ratio of (A) to (B) is 4.5-6.5: 1.

4. the method for preparing single-component geopolymer cement according to claim 1, wherein the raw materials are the metal tailings, the papermaking white mud and the feldspar, and in step S2, the metal tailings, the papermaking white mud and the feldspar are blended according to a mass ratio of 5:3:2 to prepare the admixture, wherein in the admixture, the SiO is in mass percentage₂35 to 36 percent of the Al, 30 to 31 percent of the CaO, and the Al₂O₃6 to 8 percent of SiO₂And said Al₂O₃The mass ratio of (A) to (B) is 5.65: 1.

5. the method for preparing single-component geopolymer cement as claimed in claim 1, wherein said raw materials are selected from said metal tailings, said cement kiln dust and said feldspar, and in step S2, said metal tailings, said cement kiln dust and said feldspar are blended in a mass ratio of 5:3:2 to prepare said admixture, wherein said SiO is included in said admixture by mass percentage₂36 to 38 percent of the Al, 30 to 31 percent of the CaO, and the Al₂O₃6 to 8 percent of SiO₂And said Al₂O₃The mass ratio of (A) to (B) is 5.4: 1.

6. the one-component geopolymer cement preparation method of claim 1The method is characterized in that in step S3, the Na is₂CO₃The mass fraction of the additive in the admixture is 15-25%, the calcining temperature is 1250-1350 ℃, the calcining time is 2.5-3.5 hours, and the molten material is cooled by adopting rapid air flow.

7. The method of claim 1, wherein the cooled molten material is ground and sieved to obtain the single-component geopolymer cement with a particle size of less than 50 μm, wherein the glassy material is mainly composed of amorphous substances with a mass fraction of more than 95%.

Technical Field

The invention relates to the field of cement materials, and in particular relates to a preparation method of single-component geopolymer cement.

Background

Mineral resources are the material basis upon which society is based for survival and development. At present, more than 80% of industrial raw materials and more than 70% of agricultural production data in more than 95% of domestic disposable energy sources are from mineral resources. Because the effective comprehensive utilization rate of mineral resources is low, a large amount of useful resources enter the waste tailings. Industrial waste residues and metal tailings in China are almost everywhere, and the amount of some industrial waste residues is large, such as fly ash. If the tailings are not treated and comprehensively utilized, more and more land is occupied by the tailings, secondary environmental pollution is caused, resource waste is caused, and sustainable development of mineral resources is further influenced.

The single-component geopolymer cement with metal tailings is prepared by adding solid alkali activator into metal tailings or mixture thereof, is similar to common cement, can be directly used by adding water, and has good development prospect.

Disclosure of Invention

The invention aims to provide a method for preparing single-component geopolymer cement, which aims to solve the problems of tailing accumulation, resource waste, environmental pollution and the like caused by low comprehensive utilization rate of metal tailings.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The invention provides a preparation method of single-component geopolymer cement, which comprises the following steps:

s1, obtaining raw materials, and respectively counting SiO in the raw materials₂、Al₂O₃And the content of Ca-containing compounds is obtained to obtain an analysis result, wherein the Ca-containing compounds are CaO and/or CaCO₃The raw material is selected from one or more of metal tailings, papermaking white mud, feldspar and cement kiln dust;

s2, blending the raw materials to obtain an admixture according to the analysis result;

s3, adding Na into the admixture₂CO₃Uniformly mixing, calcining, and immediately cooling the calcined molten material to obtain a calcined product;

and S4, grinding the calcined product to obtain the single-component geopolymer cement.

The preparation method of the single-component geopolymer cement has the beneficial effects that:

1. the invention utilizes the main components of metal tailings, feldspar, papermaking white mud, cement kiln dust and the like as SiO₂、Al₂O₃And CaO (CaCO)₃) The single-component geopolymer cement prepared from the industrial byproducts reduces the environmental pressure caused by the stockpiling of the metal tailings, and can realize the resource utilization of the solid wastes such as the metal tailings and the like, save energy and reduce the carbon emission due to wide raw material sources and low price.

2. The main component of the single-component geopolymer cement prepared by the invention is a glassy material which contains more than 95% of amorphous substances. The 28d cubic compressive strength of the single-component geopolymer cement is 35-45 MPa, and can reach the strength standard of No. 32.5 or No. 42.5 cement. The 3d and 7d cubic compressive strengths were 40% and 75% of the 28d cubic compressive strength, respectively. The single-component geopolymer cement has the advantages of convenience for engineering construction, good comprehensive performance, energy conservation, environmental protection and the like, and can be widely applied to the production raw materials of building material products such as concrete preparation, rock and soil mass grouting reinforcement, rapid repair of highways or airport runways, concrete prefabricated part manufacture, wall block manufacture, permeable pavement bricks, kerbs and the like.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The invention provides a preparation method of single-component geopolymer cement, which comprises the following steps:

s1, obtaining raw materials, and respectively counting SiO in the raw materials₂、Al₂O₃And the content of Ca-containing compounds, and obtaining an analysis result, wherein the raw material is selected from metal tailings, feldspar, papermaking white mud, cement kiln dust and the like, and the main component of the raw material is SiO₂、Al₂O₃And industrial by-products of Ca-containing compounds. The Ca-containing compound is CaO and/or CaCO₃Wherein CaCO₃CaO may be obtained by high temperature calcination. By comprehensively utilizing solid wastes such as metal tailings and the like, the environmental pressure caused by the stockpiling of the tailings can be reduced, and the resource utilization of the solid wastes such as the metal tailings and the like can be realized in a large scale and the energy is saved due to wide raw material sources and low price.

Further, according to the mass percentage, in the metal tailings, the SiO is contained in₂35 to 45 percent of Al₂O₃5% -8% of the white mud, 25% -30% of CaO, and SiO in the white mud₂1 to 3 percent of Al₂O₃0.2-0.8% of CaO, 45-55% of CaO, in the feldspar, the SiO₂65% -80% of Al₂O₃13% -15%, CaO 1% -3%, and in the cement kiln dust, SiO₂6 to 8 percent of Al₂O₃2 to 3 percent of CaO and 45 to 60 percent of CaO.

And S2, blending the raw materials according to the analysis result to obtain the admixture.

Further, in the admixture, the SiO is calculated by mass percentage₂30 to 45 percent of the Al₂O₃6 to 15 percent of the CaO, and 30 to 40 percent of the CaO, wherein the SiO is₂And said Al₂O₃The mass ratio of (A) to (B) is 4.5-6.5: 1.

further, the raw materials are the metal tailings, the papermaking white mud and the feldspar, the metal tailings, the papermaking white mud and the feldspar are blended according to the mass ratio of 5:3:2 to prepare the admixture, and in the admixture, the SiO is contained₂35 to 36 percent of the Al, 30 to 31 percent of the CaO, and the Al₂O₃6 to 8 percent of SiO₂And said Al₂O₃The mass ratio of (A) to (B) is 5.65: 1.

further, the raw materials are selectedThe metal tailings, the cement kiln dust and the feldspar are blended according to the mass ratio of 5:3:2 to prepare the admixture, and according to mass percent, in the admixture, the SiO is₂36 to 38 percent of the Al, 30 to 31 percent of the CaO, and the Al₂O₃6 to 8 percent of SiO₂And said Al₂O₃The mass ratio of (A) to (B) is 5.4: 1.

s3, adding Na into the admixture₂CO₃Uniformly mixing, then calcining, and immediately cooling the calcined molten material to obtain a calcined product.

Further, said Na₂CO₃The mass fraction in the admixture is 15 to 25 percent, and Na₂CO₃Used as solid alkali activator in the preparation process of single-component geopolymer cement. As the solid alkali-activator increases, the pH of the admixture increases, [ OH ]]^-The concentration is increased and the activation reaction is accelerated, but when it reaches a peak, since the reaction is too rapid, the product is not easily diffused, adheres to the surface of the fine particles to form a protective film, but prevents the further reaction, and therefore, it is preferable that Na of the present invention is used₂CO₃The mass fraction of the admixture in the admixture is 15-25%, and the admixture is ensured to have a faster reaction speed under the reaction condition. The calcination temperature is 1250-1350 ℃, and the calcination time is 2.5-3.5 hours. Through Na₂CO₃The molten material obtained by excitation and calcination for 2.5-3.5 hours at the calcination temperature has a 28d cube compressive strength of 35-45 MPa after 28d curing and has good quality, so the activation mode is a better activation mode. The molten material is cooled by adopting rapid air flow, wherein the flow velocity of the air flow is 0.6-1.5 m/s. The method effectively utilizes air flow to enhance and accelerate cooling of the molten material to improve the quality of the single-component geopolymer cement and improve its wear resistance.

And S4, grinding the calcined product to obtain the single-component geopolymer cement.

Further, after grinding the cooled molten material, screening to obtain the single-component geopolymer cement with the grain size of less than 50 mu m, wherein the main component of the single-component geopolymer cement is a glassy material, and the mass fraction of amorphous substances in the glassy material is more than 95%.

And (3) adding water into the single-component geopolymer cement, and stirring for 5 minutes after adding the water. The water-solid ratio of the water to the single-component geopolymer cement is 0.29-0.31: 1. and then, filling the single-component geopolymer cement into a steel test mould with the specification of 150cm by 150cm for curing, wherein the relative humidity of curing is 99 +/-1, the curing temperature is 23 +/-2 ℃, and the curing time is 24 hours. After curing, the mold was removed and cured again under the same conditions for 28 days.

After curing for 28 days, the 28d cubic compressive strength of the single-component geopolymer cement is 35-45 MPa, the 28d cubic compressive strength of the single-component geopolymer cement reaches the No. 32.5 or No. 42.5 cement strength standard, and the 3d cubic compressive strength and the 7d cubic compressive strength of the single-component geopolymer cement are 40% and 75% of the 28d cubic compressive strength respectively.

The single-component geopolymer cement prepared by the invention is the same as common cement, and can be widely used as a raw material for producing building material products such as concrete preparation, rock and soil mass grouting reinforcement, rapid repair of highways or airport runways, concrete prefabricated member manufacturing, wall building block manufacturing or permeable pavement bricks, curbs and the like.

The features and properties of the present invention are described in further detail below with reference to examples.