CN102180606A - Geopolymer-like cement and preparation method thereof - Google Patents

Abstract

The invention relates to a type of geopolymer cement and a preparation method thereof. The scheme is prepared according to the following components: 62-73wt% of tailings for vanadium extraction from stone coal, 5-10wt% of solid alkali metal hydroxide, 7-11wt% of solid sodium aluminate, ultrafine active micro-silicon Powder is 8-16wt% and metakaolin is 6-13wt%. The preparation steps are: firstly adding solid alkali metal hydroxide to the tailings of vanadium extraction from stone coal, stirring, dry ball milling and calcining; After dry ball milling, a geopolymer-like cement product is obtained; when in use, water is added to the cement product, grouting is performed while stirring, and a hardened slurry is formed at room temperature. The invention has the characteristics of simple operation, low cost and low degree of chemical corrosion to containers and human bodies. The hardened slurry of the prepared geopolymer cement has high compressive strength and flexural strength, and is resistant to sulfate corrosion and water immersion. It has strong resistance to corrosion, alkali-aggregate reaction, and good dry shrinkage resistance.

Description

A kind of geopolymer cement and preparation method thereof

technical field

The invention belongs to the technical field of geopolymers, and in particular relates to a kind of geopolymer cement and a preparation method thereof.

Background technique

With the continuous development of human resources and the continuous strengthening of environmental awareness, the general development trend of future materials is to gradually replace metal materials with non-metallic materials, and among non-metallic materials, inorganic materials will become more and more popular in many fields. Many places replace organic materials. The preparation of non-toxic, high-temperature-resistant, high-strength inorganic materials from extremely abundant and cheap inorganic minerals is one of the important directions of material science research in the world today. Geopolymers are a new class of high-performance inorganic polymer materials, and they are the most promising class of alkali-activated gelling materials. Geopolymers have unique properties and show great application prospects in building materials, solid waste materials, sealing materials and high temperature resistant materials.

In the process of preparing geopolymers at home and abroad, generally, the basic activator (such as sodium hydroxide, potassium hydroxide, sodium silicate, silicon dioxide, etc.) Potassium acid, etc.) to form an inorganic polymer with a certain strength and a three-dimensional network structure (Xu Yuqing, Qi Ji, Yu Hao. A new method for preparing geopolymer materials [P].CN 200710003404.6, 2007; S.Andini, R.Cioffi, F.Colangelo, et al.Coal fly ashas raw material for the manufacture of geopolymer-based products[J].Waste Management, 2008, 28:416～423), that is, "geopolymer ". Because its production process avoids the need to consume a large amount of resources and energy like the production of ordinary Portland cement, basically does not emit CO ₂ , and can use solid silica-alumina materials discarded in industrial production as raw materials, geopolymer materials have attracted attention. Attention of more and more material researchers. However, the step of "preparing alkali activator solution" is included in the traditional preparation process of geopolymers. Due to the viscous and strongly alkaline alkali activator solution, it is easy to cause chemical corrosion to the container and the human body, and the temporary preparation The alkali activator solution process is cumbersome, and there is no uniform standard for the addition of water and solid alkali activator for different silicon-aluminum raw materials, so this virtually brings great difficulties to the large-scale application of geopolymers.

Contents of the invention

The present invention aims to overcome the defects of the prior art, and the purpose is to provide a preparation method of geopolymer cement and hardened slurry thereof with simple process and low cost; the geopolymer cement prepared by the method can greatly reduce production and The degree of chemical corrosion caused to the container and the human body during use, and the hardened slurry has high compressive strength and flexural strength, strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and dry shrinkage resistance good.

In order to achieve the above object, the technical scheme adopted in the present invention is that the components and contents thereof of the geopolymer cement are:

Stone coal vanadium extraction tailings 62～73wt%;

Solid alkali metal hydroxide 5～10wt%;

Solid sodium aluminate 7～11wt%;

Ultrafine active silica fume 8～16wt%;

Metakaolin 6～13wt%;

According to the above-mentioned components and their contents, the preparation steps of this type of geopolymer cement are:

The first step is to add solid alkali metal hydroxide to the tailings of vanadium extraction from stone coal, mechanically stir for 5 to 10 minutes, and then dry ball mill in a ball mill for 10 to 15 minutes to obtain a ball mill;

The second step is to put the ball abrasive into the muffle furnace for calcination at a temperature of 300-600°C; keep the temperature for 2-4 hours to obtain the calcined material;

The third step is to cool the calcined material at room temperature, then add solid sodium aluminate, ultrafine active micro-silica powder and metakaolin to it, and mechanically stir for 5 to 10 minutes to obtain a mixture;

The fourth step is to put the mixture into a ball mill for dry ball milling for 10 to 15 minutes to prepare geopolymer cement.

In the above technical scheme: the content of _SiO2 in the tailings of vanadium extraction from stone coal is 65-85wt%, the content of _Al2O3 is _5-20wt %; the particle size is less than 0.074mm; the solid alkali metal hydroxide is hydroxide Sodium, or potassium hydroxide, or a mixture of sodium hydroxide and potassium hydroxide; the content of SiO ₂ in ultrafine active micro-silica powder is more than 95%, and the BET specific surface area is 20-40m ² /g; in metakaolin The content of SiO ₂ is 50-55 wt%, and the content of Al ₂ O ₃ is 42-47 wt%.

The preparation method of the hardened slurry of the geopolymer cement is that water is added to the prepared geopolymer cement, and the mass ratio of water to the geopolymer cement is 1: (2～3), While stirring, grouting is formed at room temperature to form a hardened slurry.

Due to the adoption of the above-mentioned technical scheme, the present invention uses waste stone coal vanadium extraction tailings as the main raw material in the use of raw materials, which not only solves the stacking problem of stone coal vanadium extraction tailings, but also broadens the source of raw materials for preparing geopolymer cement . The process of the invention is simple, and the step of "preparing the alkali activator solution" is omitted in the preparation process, so the degree of chemical corrosion to the container and the human body is greatly reduced.

The geopolymer-like cement prepared by the invention can be stored like ordinary portland cement before use; only a certain amount of water can be added to form a hardened slurry similar to geopolymer when used, and the operation is simple. The 3-day compressive strength of the hardened slurry can reach more than 30MPa, the 3-day flexural strength can reach more than 4.5MPa, the 28-day compressive strength can reach more than 50MPa, and the 28-day flexural strength can reach more than 8.5MPa. It has strong resistance to erosion, water erosion, alkali-aggregate reaction, and good dry shrinkage resistance.

Therefore, the present invention has the characteristics of simple operation, low cost and low degree of chemical corrosion to the container and the human body. The hardened slurry of the prepared geopolymer cement not only has high compressive strength and flexural strength, but also Strong resistance to salt attack, water attack, alkali-aggregate reaction, good dry shrinkage resistance.

Detailed ways

The present invention will be further described below in conjunction with specific embodiment, is not the restriction of its protection scope:

In order to avoid repetition, the raw materials to be involved in _this specific embodiment are described as follows: the content of _SiO2 in the tailings of vanadium extraction from stone coal is 65-85wt%, the content of _Al2O3 is 5-20wt%, and the particle size Less than 0.074mm; the content of SiO ₂ in ultrafine active micro-silica is more than 95%, and the BET specific surface area is 20-40m ² /g; the content of SiO ₂ in metakaolin is 50-55wt%, and the content of Al ₂ O ₃ It is 42-47wt%. Details will not be described in specific embodiments.

Example 1

A type of geopolymer cement and a preparation method thereof. The components and content of geopolymer cement are:

Vanadium extraction tailings from stone coal 62-68wt%;

Solid sodium hydroxide 5～7wt%;

Solid sodium aluminate 9～11wt%;

Ultrafine active silica fume 8～12wt%;

Metakaolin 6～9wt%;

According to the above-mentioned components and their contents, the preparation steps of this type of geopolymer cement are:

In the first step, solid sodium hydroxide is added to the tailings of vanadium extraction from stone coal, mechanically stirred for 5 to 10 minutes, and then placed in a ball mill for dry ball milling for 10 to 15 minutes to obtain a ball mill;

The second step is to put the ball abrasive into the muffle furnace for calcination at a temperature of 300-400°C; keep the temperature for 3-4 hours to obtain the calcined material;

The third step is to cool the calcined material at room temperature, then add solid sodium aluminate, ultrafine active micro-silica powder and metakaolin to it, and mechanically stir for 5 to 10 minutes to obtain a mixture;

The fourth step is to put the mixture into a ball mill for dry ball milling for 10 to 15 minutes to prepare geopolymer cement.

The preparation method of the hardened slurry of the geopolymer cement is that water is added to the prepared geopolymer cement, and the mass ratio of water to the geopolymer cement is 1: (2～3), While stirring, grouting is formed at room temperature to form a hardened slurry.

This embodiment causes low chemical corrosion to the container and the human body during the operation process, the 3-day compressive strength of the hardened slurry can reach more than 30MPa, the 3-day flexural strength can reach more than 4.5MPa, and the 28-day compressive strength can reach more than 30MPa. It can reach more than 50MPa, and the 28-day flexural strength can reach more than 8.5MPa. It has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

Example 2

A type of geopolymer cement and a preparation method thereof. The components and content of geopolymer cement are:

Vanadium extraction tailings from stone coal 68～73wt%;

Solid potassium hydroxide 5～7wt%;

Solid sodium aluminate 7～9wt%;

Ultrafine active silica fume 8～12wt%;

Metakaolin 6～9wt%;

According to the above-mentioned components and their contents, the preparation steps of this type of geopolymer cement are:

In the first step, solid potassium hydroxide is added to the tailings of vanadium extraction from stone coal, mechanically stirred for 5-10 minutes, and then placed in a ball mill for dry ball milling for 10-15 minutes to obtain a ball mill;

The second step is to put the ball abrasive into the muffle furnace for calcination at a temperature of 400-500°C; keep the temperature for 3-4 hours to obtain the calcined material;

The third step is to cool the calcined material at room temperature, then add solid sodium aluminate, ultrafine active micro-silica powder and metakaolin to it, and mechanically stir for 5 to 10 minutes to obtain a mixture;

The fourth step is to put the mixture into a ball mill for dry ball milling for 10 to 15 minutes to prepare geopolymer cement.

The preparation method of the hardened slurry of the geopolymer cement is that water is added to the prepared geopolymer cement, and the mass ratio of water to the geopolymer cement is 1: (2～3), While stirring, grouting is formed at room temperature to form a hardened slurry.

In this embodiment, the degree of chemical corrosion caused to the container and the human body during the operation is low. The 3-day compressive strength of the hardened slurry can reach more than 33MPa, the 3-day flexural strength can reach more than 5MPa, and the 28-day compressive strength can reach More than 55MPa, the 28-day flexural strength can reach more than 9MPa, and it has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

Example 3

A type of geopolymer cement and a preparation method thereof. The components and content of geopolymer cement are:

Stone coal vanadium extraction tailings 62～68wt%;

The mixture of solid sodium hydroxide and solid potassium hydroxide 5～7wt%;

Solid sodium aluminate 7～9wt%;

Ultrafine active silica fume 12～16wt%;

Metakaolin 6～9wt%;

According to the above-mentioned components and their contents, the preparation steps of this type of geopolymer cement are:

The first step, adding a mixture of solid sodium hydroxide and solid potassium hydroxide to the tailings of vanadium extraction from stone coal, mechanically stirring for 5 to 10 minutes, and then placing it in a ball mill for dry ball milling for 10 to 15 minutes to obtain a ball mill;

The second step is to put the ball abrasive into the muffle furnace for calcination at a temperature of 500-600°C; keep the temperature for 2-3 hours to obtain the calcined material;

The third step is to cool the calcined material at room temperature, then add solid sodium aluminate, ultrafine active micro-silica powder and metakaolin to it, and mechanically stir for 5 to 10 minutes to obtain a mixture;

The fourth step is to put the mixture into a ball mill for dry ball milling for 10 to 15 minutes to prepare geopolymer cement.

The preparation method of the hardened slurry of the geopolymer cement is that water is added to the prepared geopolymer cement, and the mass ratio of water to the geopolymer cement is 1: (2～3), While stirring, grouting is formed at room temperature to form a hardened slurry.

The present embodiment causes low chemical corrosion degree to the container and the human body during operation, the 3-day compressive strength of the hardened slurry can reach more than 35MPa, the 3-day flexural strength can reach more than 5.5MPa, and the 28-day compressive strength can reach more than 35MPa. It can reach more than 57MPa, and the 28-day flexural strength can reach more than 9.5MPa. It has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

Example 4

A type of geopolymer cement and a preparation method thereof. The components and content of geopolymer cement are:

Stone coal vanadium extraction tailings 62～68wt%;

The mixture of solid sodium hydroxide and solid potassium hydroxide 7～10wt%;

Solid sodium aluminate 7～9wt%;

Ultrafine active silica fume 8～12wt%;

Metakaolin 9～13wt%;

According to the above-mentioned components and their contents, the preparation steps of the geopolymer cement and the preparation method of the hardened slurry in this embodiment are the same as those in Example 3

In this embodiment, the degree of chemical corrosion caused to the container and the human body during the operation is low, the 3-day compressive strength of the hardened slurry can reach more than 35MPa, the 3-day flexural strength can reach more than 5MPa, and the 28-day compressive strength can reach More than 55MPa, the 28-day flexural strength can reach more than 9.5MPa, and it has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

Example 5

A type of geopolymer cement and a preparation method thereof. The components and content of geopolymer cement are:

Stone coal vanadium extraction tailings 68～73wt%;

The mixture of solid sodium hydroxide and solid potassium hydroxide 5～7wt%;

Solid sodium aluminate 7～9wt%;

Ultrafine active silica fume 8～12wt%;

Metakaolin 6～9wt%.

According to the above-mentioned components and their contents, the preparation steps of the geopolymer cement and the preparation method of the hardened slurry in this embodiment are the same as those in Embodiment 3.

This embodiment causes low chemical corrosion to the container and the human body during the operation process, the 3-day compressive strength of the hardened slurry can reach more than 30MPa, the 3-day flexural strength can reach more than 4.5MPa, and the 28-day compressive strength can reach more than 30MPa. It can reach more than 50MPa, and the 28-day flexural strength can reach more than 8.5MPa. It has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

In this specific embodiment, waste stone coal vanadium extraction tailings are used as the main raw material in the use of raw materials, which not only solves the stacking problem of stone coal vanadium extraction tailings, but also broadens the source of raw materials for preparing geopolymer cement. This specific embodiment has a simple process, and the step of "preparing the alkali activator solution" is omitted in the preparation process, so the degree of chemical corrosion to the container and the human body is greatly reduced.

The geopolymer-like cement prepared in this specific embodiment can be stored like ordinary Portland cement before use; only a certain amount of water needs to be added during use to form a hardened slurry similar in structure to geopolymers. Simple, the 3-day compressive strength of the hardened slurry can reach more than 30MPa, the 3-day flexural strength can reach more than 4.5MPa, the 28-day compressive strength can reach more than 50MPa, and the 28-day flexural strength can reach more than 8.5MPa. Strong resistance to sulfate attack, water attack, alkali-aggregate reaction, good dry shrinkage resistance.

Therefore, this specific embodiment has the characteristics of simple operation, low cost, and low degree of chemical corrosion to the container and the human body. The hardened slurry of the prepared geopolymer cement not only has high compressive strength and flexural strength, but also It has strong resistance to sulfate attack, water attack, alkali-aggregate reaction, and good dry shrinkage resistance.

Claims (7)

1. A preparation method of a kind of geopolymer cement, characterized in that the component and content thereof of this kind of geopolymer cement are: Stone coal vanadium extraction tailings 62～73wt%; Solid alkali metal hydroxide 5～10wt%; Solid sodium aluminate 7～11wt%; Ultrafine active silica fume 8～16wt%; Metakaolin 6～13wt%; The preparation steps of this type of geopolymer cement are, according to the above-mentioned components and their contents: The first step is to add solid alkali metal hydroxide to the tailings of vanadium extraction from stone coal, mechanically stir for 5 to 10 minutes, and then dry ball mill in a ball mill for 10 to 15 minutes to obtain a ball mill; The second step is to put the ball abrasive into the muffle furnace for calcination at a temperature of 300-600°C; keep the temperature for 2-4 hours to obtain the calcined material; The third step is to cool the calcined material at room temperature, then add solid sodium aluminate, ultrafine active micro-silica powder and metakaolin to it, and mechanically stir for 5 to 10 minutes to obtain a mixture; The fourth step is to put the mixture into a ball mill for dry ball milling for 10 to 15 minutes to prepare geopolymer cement. 2. The preparation method of geopolymer cement according to claim 1, characterized in that the content of _SiO2 in the described stone coal vanadium extraction tailings is 65-85wt%, and the content of _Al2O3 is _5-85wt %. 20wt%; particle size less than 0.074mm. 3. the preparation method of geopolymer cement according to claim 1 is characterized in that described solid alkali metal hydroxide is sodium hydroxide or is potassium hydroxide or is sodium hydroxide and potassium hydroxide mixture. 4. The preparation method of geopolymer-like cement according to claim 1, characterized in that the content of _SiO2 in the ultrafine active micro-silica powder is more than 95%, and the BET specific surface area is ^20-40m2 /g . 5. The preparation method of geopolymer cement according to claim 1, characterized in that the content of SiO ₂ in the metakaolin is 50-55 wt%, and the content of Al ₂ O ₃ is 42-47 wt%. 6. The geopolymer-like cement prepared by the method for preparing geopolymer-like cement according to any one of claims 1-5. 7. the hardening slurry preparation method of a kind of geopolymer cement as claimed in claim 1, is characterized in that adding water in the prepared geopolymer cement, the mass ratio of water and geopolymer cement is 1: (2~3), grouting while stirring, forming a hardened slurry at room temperature.