阅读说明：本技术 一种促凝剂及其制备方法和用途 (Coagulant and preparation method and application thereof ) 是由 李帆 陈红霞 冉秀云 戚婷婷 王霞 张晓菲 于 2018-07-27 设计创作，主要内容包括：一种促凝剂及其制备方法和用途。所述促凝剂包括生石膏、助磨剂和聚磷酸盐。所述促凝剂通过将生石膏、助磨剂和聚磷酸盐混合、研磨制备得到。该促凝剂无需现制备立刻使用,是一种高效、稳定的石膏板促凝剂,使得纸面石膏板的制备过程更加便利。(A coagulant and its preparation method and application are provided. The set accelerator comprises gypsum, a grinding aid and polyphosphate. The coagulant is prepared by mixing and grinding gypsum, grinding aid and polyphosphate. The coagulant is used immediately without preparation, is a high-efficiency and stable gypsum board coagulant, and facilitates the preparation process of the gypsum board.)

1. A set accelerator comprising gypsum, a grinding aid and polyphosphate.

2. The setting accelerator according to claim 1, wherein the grade of the raw gypsum is greater than 85%;

optionally, the gypsum is desulfurized gypsum;

optionally, the water content of the gypsum is less than 0.5%.

3. The setting accelerator according to claim 1 or 2, wherein the grinding aid is a sugar and/or starch;

optionally, the sugar is an industrial sugar;

optionally, the water content of the grinding aid is less than 0.5%.

4. The setting accelerator according to claim 1 or 2, wherein the weight ratio of grinding aid to gypsum is from 1 to 10: 100;

optionally, the weight ratio of the polyphosphate to the mixture consisting of the grinding aid and the gypsum is 1-10: 100.

5. The setting accelerator according to claim 1 or 2, wherein the setting accelerator has an average particle size of not more than 20 μm.

6. A process for preparing an accelerator according to any one of claims 1 to 5, which comprises the steps of: mixing and grinding gypsum, a grinding aid and polyphosphate to obtain the coagulant.

7. The method of claim 6, further comprising: drying the phosphogypsum and the grinding aid until the water content is lower than 0.5 percent before mixing the gypsum and the grinding aid.

8. The process according to claim 6 or 7, wherein the average particle size of the coagulant obtained by grinding is not greater than 20 μm;

optionally, the grinding time is 20-40 min;

optionally, the rotation speed of grinding can be 300-500 r/min;

optionally, the temperature of the milling is below 45 ℃.

9. Use of the setting accelerator according to any of claims 1 to 5 or the setting accelerator prepared according to the process of any of claims 6 to 8 for the preparation of paper-faced gypsum board.

10. The use according to claim 9, wherein the coagulant is added in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the added gypsum clinker in the raw material for producing the paper-faced gypsum board.

11. The use of claim 10, wherein the raw materials for preparing the paper-surface gypsum board further comprise water, a binder, a water reducing agent and a foaming agent, based on 100 parts by weight of the added gypsum clinker, the added amount of the water is 55-85 parts by weight, the added amount of the binder is 0.4-1 part by weight, the added amount of the water reducing agent is 0.05-0.5 part by weight, and the added amount of the foaming agent is 0.1-1 part by weight.

12. The use according to claim 11, wherein,

the binder is selected from any one or more of native starch, modified corn starch and modified tapioca starch;

optionally, the water reducing agent is selected from any one or more of polycarboxylic acid water reducing agents and naphthalene water reducing agents;

optionally, the foaming agent is selected from any one or more of surfactant foaming agents, and is further optionally selected from any one or more of sodium lauryl sulfate and fatty acid foaming agents.

Technical Field

The present application relates to, but is not limited to, the field of building materials, and in particular, but not limited to, a method for the preparation of an accelerator and its use.

Background

The paper-surface gypsum board is one of the most widely used green building materials in China. The production and consumption of gypsum boards during the 'twelve five' period show an increasing trend, more than 20% of each year is achieved, and the production of gypsum boards in China exceeds 35 hundred million square meters in 2015.

Setting accelerators are required to be added to complete the setting during the gypsum board production process. The coagulant used in the prior art is gypsum powder, the particle size of the gypsum powder is large, generally 0.01-0.02 mm, the specific surface area is small, and the particle size is only 6000-7000 cm²And about/g. Therefore, in the production of gypsum plasterboards, the amount of accelerator added must be increased in order to exert its normal accelerating effect.

The production rate of modern gypsum board factories is as high as 180m/min, and in order to meet the production requirements, more efficient and stable coagulants are required.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

Gypsum is currently the most widely used coagulant. However, gypsum as a setting accelerator needs to be prepared and used immediately, otherwise, the setting accelerator effect is affected. In order to solve the above problems, the present application intends to provide an efficient and stable accelerator for gypsum boards.

Provided herein is a set accelerator comprising gypsum, a grinding aid, and polyphosphate.

The polyphosphate is added into the coagulant, so that the change of the coagulant in the air can be effectively avoided, and the due coagulation accelerating effect can be maintained.

In some embodiments, the grade of the gypsum can be greater than 85%; the gypsum can be desulfurized gypsum; the water content of the gypsum may be less than 0.5%.

The water content of the raw materials is controlled, the phenomenon of ball sticking is avoided, and the input-output ratio is improved.

In some embodiments, the grinding aid can be a sugar and/or starch; the sugar can be industrial sugar; the water content of the grinding aid can be lower than 0.5 percent.

Because the hardness of the sugar is higher, the sugar is adopted as the grinding aid, so that the addition amount of the grinding aid can be reduced, and the production cost is reduced.

In some embodiments, the weight ratio of grinding aid to gypsum can be 1-10: 100; the weight ratio of the polyphosphate to the mixture consisting of the grinding aid and the gypsum can be 1-10: 100.

In some embodiments, the average particle size of the coagulant is not greater than 20 μm.

The smaller the particle size of the setting accelerator, the better the setting accelerator effect, and in the present application, the setting accelerator having an average particle size of not more than 20 μm can obtain a good setting accelerator effect.

The present application also provides a method of setting accelerator, comprising the steps of: mixing and grinding gypsum, a grinding aid and polyphosphate to obtain the coagulant.

In some embodiments, the method further comprises: before mixing the gypsum and the grinding aid, drying the phosphogypsum and the grinding aid until the water content is lower than 0.5 percent.

In some embodiments, the grade of the gypsum can be greater than 85%; the gypsum can be desulfurized gypsum.

In some embodiments, the grinding aid can be a sugar and/or starch; the sugar may be an industrial sugar.

In some embodiments, the weight ratio of grinding aid to gypsum can be 1-10: 100; the weight ratio of the polyphosphate to the mixture consisting of the grinding aid and the gypsum can be 1-10: 100.

In some embodiments, the average particle size of the accelerator resulting from milling may be no greater than 20 μm; the grinding time can be 20-40 min; the rotation speed of the grinding can be 300-500 r/min; the temperature of the milling may be below 45 ℃.

At high temperatures, the grinding aid may melt and agglomerate, resulting in deterioration of accelerator performance, and therefore the temperature of grinding can be controlled below 45 ℃.

The application also provides the use of the setting accelerator or the setting accelerator prepared by the method in the preparation of gypsum plasterboards.

In some embodiments, the coagulant may be added in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the gypsum clinker in the raw material for producing the paper-faced gypsum board.

In some embodiments, the raw materials for preparing the paper-surface gypsum board further comprise water, a binder, a water reducing agent and a foaming agent, wherein the water can be added in an amount of 55-85 parts by weight, the binder can be added in an amount of 0.4-1 part by weight, the water reducing agent can be added in an amount of 0.05-0.5 part by weight, and the foaming agent can be added in an amount of 0.1-1 part by weight, based on 100 parts by weight of the gypsum clinker.

In some embodiments, the binder may be selected from any one or more of native starch, modified corn starch, and modified tapioca starch; the water reducing agent can be selected from any one or more of polycarboxylic acid water reducing agents and naphthalene water reducing agents; the foaming agent may be selected from any one or more of surfactant based foaming agents, for example may be selected from any one or more of sodium lauryl sulfate and fatty acid based foaming agents.

Compared with the prior art, the application has the beneficial effects that:

1. according to the coagulant, sugar or starch grinding aids are added for grinding, so that the obtained coagulant can effectively shorten the initial setting time and final setting time of the gypsum board, and is more efficient;

2. the polyphosphate is added into the coagulant, so that the change of the coagulant in the air can be effectively avoided, the due coagulation accelerating effect is maintained, and the coagulant can be immediately used without preparation;

3. the present application provides a high efficiency, stable gypsum board set accelerator; the application of the coagulant facilitates the preparation process of the paper-surface gypsum board.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the claimed subject matter and are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and together with the description serve to explain the principles of the subject matter and not to limit the subject matter.

FIG. 1 is a graph of the moisture-dependent distribution of the particle size of the setting accelerator according to example 1 of the present application;

FIG. 2 is a graph showing the moisture-dependent distribution of the particle size of the setting accelerator of comparative example 1 of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The raw gypsum used in the following examples and comparative examples is desulfurized gypsum produced in a power plant and has a grade of 86%.