阅读说明：本技术 一种高性能新型白水泥的制备方法 (Preparation method of high-performance novel white cement ) 是由 白吉元 于 2021-11-08 设计创作，主要内容包括：本发明公开了一种高性能新型白水泥的制备方法,按质量百分比取18％～25％的预处理后的粉煤灰,40％的α型半水石膏,25％～30％的煅烧石膏,9％～14％的预处理后的生石灰粉,1％的添加剂,将各组分送入研磨装置磨粉至细度180～320目即可。本发明的新型白水泥的制备方法通过利用粉煤灰、α型半水石膏、煅烧石膏、生石灰粉等原材料按照一定比例混合研磨即可,操作简单,生产效率高,生产的白水泥七天抗压强度最高可达到39Mpa,产品质量性能得到大幅提升,并且通过使用价格低廉的粉煤灰作为原材料,相较于传统的白水泥生产成本降低了40％～50％,能够带来较高的经济效益。(The invention discloses a preparation method of high-performance novel white cement, which comprises the steps of taking 18-25% of pretreated fly ash, 40% of alpha-type semi-hydrated gypsum, 25-30% of calcined gypsum, 9-14% of pretreated quicklime powder and 1% of additive by mass percent, and feeding the components into a grinding device to be ground into powder with the fineness of 180-320 meshes. The preparation method of the novel white cement provided by the invention is characterized in that the raw materials such as the fly ash, the alpha-type semi-hydrated gypsum, the calcined gypsum and the quicklime powder are mixed and ground according to a certain proportion, the operation is simple, the production efficiency is high, the highest seven-day compressive strength of the produced white cement can reach 39Mpa, the product quality performance is greatly improved, and the fly ash with low price is used as the raw material, so that the production cost is reduced by 40% -50% compared with the traditional white cement, and higher economic benefits can be brought.)

1. A preparation method of high-performance novel white cement is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: pretreating fly ash: sequentially carrying out magnetic separation screening, decoloring, washing, drying and grinding on the fly ash to form an effective solid component of the fly ash with the whiteness of more than 75% and the fineness of 60 meshes;

step two: preparing alpha-type semi-hydrated gypsum: grinding natural gypsum ore to 60-mesh fineness, and then putting the natural gypsum ore into a high-pressure tank to steam under saturated steam to generate alpha-type semi-hydrated gypsum;

step three: preparing calcined gypsum: grinding natural gypsum ore to 60-mesh fineness, and calcining to generate calcined gypsum;

step four: preprocessing quicklime: grinding quicklime with whiteness of more than 75% to 60 meshes;

step five: taking 18-25% of fly ash effective solid components, 40% of alpha-type semi-hydrated gypsum, 25-30% of calcined gypsum, 9-14% of pretreated quicklime powder and 1% of additive by mass percent, feeding the components into a grinding device, and grinding the components to the fineness of 180-320 meshes.

2. The method for preparing high-performance novel white cement according to claim 1, wherein: the decoloring process in the first step comprises the following steps: adding dilute hydrochloric acid with the concentration of 0.2% -1.7% into components with the whiteness of 75% or less after magnetic separation and screening for decolorization, wherein the solid content in a reaction mixture is 12% -26%, continuously reacting for 2-6 hours, rotating speed of a stirring paddle is 65-85 r/min, separating by using a centrifugal separation device after the decolorization is finished, and collecting solid components.

3. The method for preparing high-performance novel white cement according to claim 2, wherein: adding water into the decolorized solid component, controlling the solid content to be 15% -30%, simultaneously adding a sodium carbonate solution with the concentration of 0.2%, stirring for reaction, wherein the rotation speed of a stirring paddle is 65-85 r/min, the stirring time is 30 min, neutralizing until the pH value is 8.5-9, centrifugally separating and collecting the solid component, washing for 1-2 times by using deionized water, and controlling the content of water-soluble impurities in the solid component to be not higher than 120 PPM.

4. The method for preparing high-performance novel white cement according to claim 3, wherein: and (3) putting the solid component with the whiteness of more than 75% after washing into a converter for drying, and putting the dried solid component into a Raymond mill for grinding until the fineness is 60 meshes.

5. The method for preparing high-performance novel white cement according to claim 1, wherein: and in the step two, during the preparation of the alpha-hemihydrate gypsum, the saturated water vapor temperature is 124 ℃, the pressure is 0.3-0.45 Mpa, and the steaming time is 2.5-4 hours.

6. The method for preparing high-performance novel white cement according to claim 1, wherein: and in the third step, when the gypsum is calcined, the calcining temperature is 450-600 ℃, and the calcining time is 1.5 hours.

7. The method for preparing high-performance novel white cement according to claim 1, wherein: the additives in the step five comprise an organic high molecular polymer composite waterproof agent, an organic high molecular compound water reducing agent and a self-leveling additive, wherein the mass ratio of the organic high molecular polymer composite waterproof agent to the organic high molecular compound water reducing agent to the self-leveling additive is 2.8: 2.8: 1.

8. the method for preparing high-performance novel white cement according to claim 7, wherein: the organic high molecular compound composite waterproof agent is polymethyl dioxy silane, the organic high molecular compound water reducing agent is prepared by mixing lignosulfonate and naphthalene sulfonate formaldehyde polymer in a mass ratio of 1:1, and the self-leveling additive is polyamide resin.

9. The method for preparing high-performance novel white cement according to claim 1, wherein: and recycling the solution separated and generated in the first step.

Technical Field

The invention relates to the technical field of building material production, in particular to a preparation method of high-performance novel white cement.

Background

The white cement is an important building decoration material, has typical characteristics of higher whiteness and bright color, is generally used as various building decoration materials, typically comprises whitewash, sculpture, ground, terrazzo products and the like, can also be used for manufacturing white and colored concrete members, is a decoration cement variety with the largest production scale, is mostly made of limestone and clay at present, and has low strength and high production cost. The fly ash is tiny ash particles discharged in the combustion process of fuel (mainly coal), and the particle size of the fly ash is generally between 1 and 100 mu m. Which is a fine solid particulate in the ash of flue gases produced by the combustion of fuels, such as the fine ash collected from flue gases in coal-fired power plants. The fly ash is formed by cooling pulverized coal after the pulverized coal enters a hearth at 1300-1500 ℃ and is subjected to heat absorption by a hot surface under the condition of suspension combustion, and most of the fly ash is spherical due to the action of surface tension, the surface of the fly ash is smooth, and micropores are small. Some of the particles are adhered by colliding with each other in a molten state, and thus, they become honeycomb-shaped composite particles having rough surfaces and many edges. The chemical composition of fly ash is related to the composition of coal, the particle size of coal, the type of boiler, the combustion condition and the collection mode. The amount of fly ash discharged is directly related to the ash content of the coal. According to the coal use condition of China, about 250-300 kg of fly ash is generated by burning 1 ton of coal, if a large amount of fly ash is not controlled or treated, the fly ash causes atmospheric pollution, and the fly ash enters water to block river channels, wherein certain chemical substances cause harm to organisms and human bodies. At present, although the fly ash is applied to the field of building materials, the fly ash is limited by process technology, the added value of products is low, and the consumption is insufficient, so that the produced fly ash cannot be completely digested. Therefore, in order to solve the above technical problems, it is necessary to develop a method for preparing white cement using fly ash as a raw material, which has a simple production process, a high product strength, and a low production cost.

Disclosure of Invention

Aiming at the technical problems, the invention provides the method for preparing the white cement by taking the fly ash as the raw material, which has the advantages of simple production process, higher product strength and low production cost.

In order to solve the technical problems, the preparation method of the high-performance novel white cement comprises the following steps:

the method comprises the following steps: pretreating fly ash: sequentially carrying out magnetic separation screening, decoloring, washing, drying and grinding on the fly ash to form an effective solid component of the fly ash with the whiteness of more than 75% and the fineness of 60 meshes;

step two: preparing alpha-type semi-hydrated gypsum: grinding natural gypsum ore to 60-mesh fineness, and then putting the natural gypsum ore into a high-pressure tank to steam under saturated steam to generate alpha-type semi-hydrated gypsum;

step three: preparing calcined gypsum: grinding natural gypsum ore to 60-mesh fineness, and calcining to generate calcined gypsum;

step four: preprocessing quicklime: grinding quicklime with whiteness of more than 75% to 60 meshes;

step five: taking 18-25% of fly ash effective solid components, 40% of alpha-type semi-hydrated gypsum, 25-30% of calcined gypsum, 9-14% of pretreated quicklime powder and 1% of additive by mass percent, feeding the components into a grinding device, and grinding the components to the fineness of 180-320 meshes.

Further, the decoloring process in the first step comprises the following steps: adding dilute hydrochloric acid with the concentration of 0.2% -1.7% into components with the whiteness of 75% or less after magnetic separation and screening for decolorization, wherein the solid content in a reaction mixture is 12% -26%, continuously reacting for 2-6 hours, rotating speed of a stirring paddle is 65-85 r/min, separating by using a centrifugal separation device after the decolorization is finished, and collecting solid components.

And further, adding water into the decolorized solid component, controlling the solid content to be 15% -30%, simultaneously adding a sodium carbonate solution with the concentration of 0.2%, stirring for reaction, wherein the rotation speed of a stirring paddle is 65-85 r/min, the stirring time is 30 min, neutralizing until the pH value is 8.5-9, centrifugally separating and collecting the solid component, washing for 1-2 times by using deionized water, and controlling the content of water-soluble impurities in the solid component to be not higher than 120 PPM.

Further, the solid component with the whiteness of more than 75 percent after being washed by water is put into a converter for drying, and the dried solid component is put into a Raymond mill for grinding to the fineness of 60 meshes.

Further, when the alpha-type semi-hydrated gypsum is prepared in the second step, the saturated steam temperature is 124 ℃, the pressure is 0.3-0.45 Mpa, and the steaming time is 2.5-4 hours.

Further, when the gypsum is calcined in the third step, the calcining temperature is 450-600 ℃, and the calcining time is 1.5 hours.

Further, the additives in the fifth step comprise an organic high molecular polymer composite waterproof agent, an organic high molecular compound water reducing agent and a self-leveling additive, wherein the mass ratio of the organic high molecular polymer composite waterproof agent to the organic high molecular compound water reducing agent to the self-leveling additive is 2.8: 2.8: 1.

further, the organic high-molecular polymer composite waterproof agent is polymethyl dioxy silane, the organic high-molecular compound water reducing agent is prepared by mixing lignosulfonate and naphthalene sulfonate formaldehyde polymer in a mass ratio of 1:1, and the self-leveling additive is polyamide resin.

Further, the solution separated and generated in the first step is recycled.

Compared with the prior art, the invention has the following advantages:

1. the preparation method of the novel white cement provided by the invention is characterized in that the raw materials such as the fly ash, the alpha-type semi-hydrated gypsum, the calcined gypsum and the quicklime powder are mixed and ground according to a certain proportion, the operation is simple, the production efficiency is high, the highest seven-day compressive strength of the produced white cement can reach 39Mpa, the product quality performance is greatly improved, and the fly ash with low price is used as the raw material, so that the production cost is reduced by 40% -50% compared with the traditional white cement, and higher economic benefits can be brought.

2. The preparation method of the novel white cement can greatly improve the utilization rate of the fly ash, effectively reduce the pressure of the fly ash on the environment, produce environment-friendly and energy-saving products and realize circular economy.

3. According to the preparation method of the novel white cement, additives such as a waterproof agent, a water reducing agent and a self-leveling additive are added, so that the waterproof performance of the white cement is effectively improved, and the product performance is greatly improved.

4. The preparation method of the novel white cement recycles the solution generated in the production process according to the condition, and the unusable solution is directly discharged into a sewage plant for treatment, thereby effectively improving the resource utilization rate and preventing the environmental pollution.

Drawings

Fig. 1 is a flow chart of a white cement manufacturing process according to the present invention.

Detailed Description

The invention is further described in the following description with reference to the drawings.

Example 1:

as shown in fig. 1, when white cement is produced, the preparation method of the novel high-performance white cement prepares production raw materials such as fly ash, gypsum ore, quicklime and the like, and specifically comprises the following steps:

the method comprises the following steps: pretreating fly ash: in order to remove unusable metal impurities such as iron and the like in the fly ash, the fly ash is put into a vibrating screen with a magnetic separation device, so that components with different particle sizes and different chemical components in the fly ash are respectively settled into different settling collection bins, the black particle component separated by magnetic separation is directly sold at a low price, and the component with the whiteness of more than 75 percent is developed to the fineness of 60 meshes and stored for later use; in order to enable the whiteness of the fly ash raw material to meet the requirement, adding components with the whiteness of 75% or less after magnetic separation screening into dilute hydrochloric acid with the concentration of 1.7% for decolorization, wherein the solid content in a reaction mixture is 26%, continuously reacting for 6 hours, controlling the rotating speed of a stirring paddle to be 85 rpm, separating by using a centrifugal separation device after the decolorization is finished, collecting solid components, recycling the solution generated in the process according to the situation in order to improve the resource utilization rate and reduce the environmental pollution, and sending the solution which cannot be recycled into a sewage treatment plant for treatment; adding water into the decolored solid component, controlling the solid content to be 30%, simultaneously adding a sodium carbonate solution with the concentration of 0.2%, stirring and reacting, wherein the stirring paddle is rotated by 85 r/min, the reaction time is 30 min, neutralizing to the pH value of 9, centrifugally separating and collecting the solid component, washing for 2 times by using deionized water, controlling the content of water-soluble impurities in the solid separated component to be not higher than 120PPM, recycling the solution generated by separation in the process according to the situation, and sending the solution which cannot be recycled into a sewage treatment plant for treatment; and (3) putting the solid component with the whiteness of more than 75% after washing into a converter for drying, and putting the dried solid component into a Raymond mill for grinding until the fineness is 60 meshes for storage and later use.

Step two: preparing alpha-type semi-hydrated gypsum: grinding natural gypsum ore to 60 meshes, putting the ground natural gypsum ore into a high-pressure tank, and steaming for 4 hours at 124 ℃ and 0.45Mpa of saturated steam to generate alpha-type semi-hydrated gypsum;

step three: preparing calcined gypsum: grinding natural gypsum ore to 60-mesh fineness, and calcining at 600 ℃ for 1.5 hours to generate calcined gypsum;

step four: preprocessing quicklime: grinding quicklime with whiteness of more than 75% to 60 meshes;

step five: taking 25% of fly ash effective solid component, 40% of alpha-type semi-hydrated gypsum, 25% of calcined gypsum, 9% of quicklime powder and 1% of additive according to mass percentage, wherein: the additive is an organic high molecular polymer composite waterproof agent, an organic high molecular compound water reducing agent and a self-leveling additive in a mass ratio of 2.8: 2.8: 1, preparing an organic high molecular polymer composite waterproof agent by using polymethyl dioxysilane as a component, preparing an organic high molecular compound water reducing agent by using lignosulfonate and naphthalene sulfonate formaldehyde polymer in a mass ratio of 1:1, and using polyamide resin as a self-leveling additive; the components are sent into a Raymond mill according to the proportion and ground into powder with the fineness of 320 meshes, and the powder is packaged and stored.

The initial setting time of the white cement prepared in the embodiment is 60-90 minutes in the using process, the 24-hour compressive strength is 10.2Mpa, the 7-day compressive strength is 32.5Mpa, and the 28-day compressive strength is 32.5Mpa, so that the production cost is reduced by 50% compared with the traditional white cement, and the white cement can be used as an ideal caulking and filling material for indoor buildings.

Example 2:

a method for preparing high-performance novel white cement as shown in fig. 1 is different from example 1 in that, when white cement is produced: in the first step, the concentration of dilute hydrochloric acid is 0.2% during decoloring, the solid content in the reaction mixture is 12%, the reaction is continued for 2 hours, the solid content is controlled to be 15% during water washing, the neutralization is carried out until the pH value is 8.5, the deionized water is washed for 1 time, and the rotating speed of a stirring paddle is controlled to be 65 revolutions per minute; in the second step, the saturated steam pressure is 0.3Mpa and the steaming time is 2.5 hours when the alpha-hemihydrate gypsum is prepared; when the calcined gypsum is prepared in the third step, the calcining temperature is 450 ℃; and step five, taking the effective solid component of the fly ash with the doping amount of 18 percent, the alpha-type semi-hydrated gypsum with the doping amount of 40 percent, the calcined gypsum with the doping amount of 27 percent, the quicklime powder with the doping amount of 14 percent and the additive with the doping amount of 1 percent according to the mass percent, feeding the components into a Raymond mill according to the proportion, grinding the components to the fineness of 180 meshes, and bagging and storing the components.

The initial setting time of the white cement prepared in the embodiment is 75-100 minutes in the using process, the 24-hour compressive strength is 11.3Mpa, the 7-day compressive strength is 37Mpa, and the 28-day compressive strength is 40Mpa, so that the production cost is reduced by 40% compared with the traditional white cement, and the white cement prepared in the embodiment has higher strength and is an indoor and outdoor decorative material with low cost and high strength.

Example 3:

the preparation method of the high-performance novel white cement shown in fig. 1 is different from the preparation method of the examples 1 and 2 in the production of the white cement: in the first step, the concentration of dilute hydrochloric acid is 0.9% during decoloring, the solid content in the reaction mixture is 19%, the reaction is continued for 4 hours, the solid content is controlled to be 23% during water washing, the neutralization is carried out until the pH value is 8.7, the deionized water is washed for 2 times, and the rotating speed of a stirring paddle is controlled to be 75 revolutions per minute; in the second step, the saturated steam pressure is 0.38Mpa and the steaming time is 3.2 hours when the alpha-hemihydrate gypsum is prepared; when the calcined gypsum is prepared in the third step, the calcining temperature is 530 ℃; and step five, taking 20% of fly ash effective solid component, 40% of alpha-type semi-hydrated gypsum, 30% of calcined gypsum, 9% of quicklime powder and 1% of additive according to mass percentage, feeding the components into a Raymond mill according to the above proportion, grinding the components to the fineness of 250 meshes, and bagging and storing.

The initial setting time of the white cement prepared in the embodiment is 90-120 minutes in the using process, the 24-hour compressive strength is 12.7Mpa, the 7-day compressive strength is 39Mpa, and the 28-day compressive strength is 39Mpa, and compared with the traditional white cement, the production cost is reduced by 40%, and the white cement produced in the embodiment is suitable for being used as a structure and a casting grinding tool material, is an ideal casting artwork and handicraft raw material, and can also be used as a decoration material.