阅读说明：本技术 一种α高强石膏的生产工艺 (Production process of alpha high-strength gypsum ) 是由 李银保 卢文运 朱向红 曹德生 季娟 娄广辉 徐亚中 巴太斌 李文锋 张伟超 李 于 2019-10-25 设计创作，主要内容包括：本发明属于固体废弃物综合利用领域,具体涉及工业副产石膏的回收利用领域,更具体涉及一种α高强石膏的生产工艺,包括以下步骤：向工业副产石膏中加水搅拌,至工业副产石膏呈半干塑状,再经均化陈化、打散处理后,加入石膏晶种、媒晶剂,并加水搅拌至混合物料呈半干塑状,随后进行装盘布料入反应釜,通入蒸汽,在120～140℃下,进行湿热脱水反应2～3h后制得α高强石膏。由本发明制得的α高强石膏均能达到JC/T2038-2010标准中对α高强石膏的最低强度要求,并且,本发明制备α高强石膏的方法具有成本低、绿色节能的优点。(The invention belongs to the field of comprehensive utilization of solid wastes, particularly relates to the field of recycling of industrial byproduct gypsum, and more particularly relates to a production process of alpha high-strength gypsum, which comprises the following steps: adding water into the industrial byproduct gypsum, stirring until the industrial byproduct gypsum is in a semi-dry plastic shape, homogenizing, aging, scattering, adding gypsum seed crystals and a mordant, adding water, stirring until the mixed material is in a semi-dry plastic shape, then loading, distributing into a reaction kettle, introducing steam, and carrying out a damp-heat dehydration reaction for 2-3 hours at 120-140 ℃ to obtain the alpha high-strength gypsum. The alpha high-strength gypsum prepared by the method can meet the minimum strength requirement of JC/T2038-2010 standard on the alpha high-strength gypsum, and the method for preparing the alpha high-strength gypsum has the advantages of low cost, greenness and energy conservation.)

1. The production process of the alpha high-strength gypsum is characterized by comprising the following steps:

(1) adding water into the industrial by-product gypsum and stirring until the industrial by-product gypsum is in a semi-dry plastic shape;

(2) piling and aging semi-dry plastic industrial byproduct gypsum and then scattering the gypsum;

(3) adding gypsum seed crystal and a mordant into the scattered industrial byproduct gypsum, and adding water and stirring until the mixed material is in a semi-dry plastic shape;

(4) and (3) loading the semi-dry plastic mixed material into a reaction kettle, distributing the mixed material into the reaction kettle, introducing steam, and carrying out wet-heat dehydration reaction for 2-3 h at 120-140 ℃ to obtain the alpha high-strength gypsum.

2. The production process of the alpha high-strength gypsum according to claim 1, wherein the gypsum seed is alpha high-strength gypsum dry powder.

3. The production process of the alpha high-strength gypsum according to claim 2, wherein the alpha high-strength gypsum prepared in the step (4) is dried and ground to obtain alpha high-strength gypsum dry powder, and the obtained alpha high-strength gypsum dry powder is used as gypsum seed crystal.

4. The production process of the alpha high-strength gypsum according to claim 1, wherein the addition amount of the gypsum seed crystal is 10-15% (w/w) of the weight of the raw material industry byproduct gypsum; the addition amount of the mordant is 0.05-0.15% (w/w) of the weight of the byproduct gypsum in the raw material industry.

5. The process for producing alpha high-strength gypsum according to claim 4, wherein the mordant is a composition obtained by mixing industrial salts and organic acids according to a weight ratio of 1: 1.

6. The process for producing alpha high strength gypsum according to claim 5, wherein the mordant is a composition obtained by mixing aluminum sulfate and citric acid in a weight ratio of 1: 1.

7. The production process of the alpha high-strength gypsum according to claim 6, wherein the industrial by-product gypsum is one or more of phosphogypsum, desulfurized gypsum and titanium gypsum.

8. The production process of the alpha high-strength gypsum according to claim 7, wherein when the industrial by-product gypsum contains phosphogypsum, a modifier is required to be added into the industrial by-product gypsum, and the addition amount of the modifier is 1-3% of the weight of the phosphogypsum.

9. The production process of the alpha high strength gypsum according to claim 8, wherein the modifier is calcium oxide powder.

10. The production process of the alpha high-strength gypsum according to any one of claims 1 to 9, wherein the external drainage water generated by the wet and hot dehydration reaction in the step (4) is recycled as water for the step (1) and the step (3).

Technical Field

The invention belongs to the field of comprehensive utilization of solid wastes, particularly relates to the field of recycling of industrial byproduct gypsum, and more particularly relates to a process for producing alpha high-strength gypsum by using the industrial byproduct gypsum.

Background

By the end of 2015 years, the total annual emission amount of industrial byproduct gypsum in China is about 185 Mt; the accumulated stacking quantity of only phosphogypsum is about 300Mt, the accumulated stacking quantity of desulfurized gypsum is about 150Mt, and other industrial by-product gypsum such as titanium gypsum, waste ceramic mold gypsum, mirabilite gypsum, fluorgypsum, salt gypsum, lemon gypsum and the like gradually increase in recent years, most of the gypsum is stacked as waste, and serious pollution is caused to the environment.

In order to realize the comprehensive utilization of resources and reduce environmental pollution, the production of the alpha high-strength gypsum by taking the industrial byproduct gypsum such as desulfurized gypsum, citric acid waste slag or phosphogypsum and the like as raw materials is gradually started in China, but a common key technology for the industrial byproduct gypsum is lacked at present, and particularly a low-cost pretreatment technology for the industrial byproduct gypsum and an application technology for large-scale high-added-value and high-performance high-end products are lacked. The traditional process and equipment generally have the problems of large product quality fluctuation, small single-line scale, low single-machine yield, poor running stability, low process technology level, simple and crude equipment, high difficulty in process control and adjustment of a production line, poor workshop-type operating environment, high energy consumption, low energy efficiency, low automation level and the like, cannot meet the requirement of large-scale industrial production, and become one of bottlenecks for restricting sustainable development of related industrial fields in China.

Disclosure of Invention

The invention aims to provide a process for preparing alpha high-strength gypsum by using industrial byproduct gypsum, which has the advantages of low cost, greenness and energy conservation.

Based on the purpose, the invention adopts the following technical scheme: the production process of the alpha high-strength gypsum comprises the following steps:

(1) adding water into the industrial by-product gypsum and stirring until the industrial by-product gypsum is in a semi-dry plastic shape;

(2) piling and aging semi-dry plastic industrial byproduct gypsum;

(3) adding gypsum seed crystal and a mordant into the scattered industrial byproduct gypsum, and adding water and stirring until the mixed material is in a semi-dry plastic shape;

(4) and (3) loading the semi-dry plastic mixed material into a reaction kettle, distributing the mixed material into the reaction kettle, introducing steam, and carrying out wet-heat dehydration reaction for 2-3 h at 120-140 ℃ to obtain the alpha high-strength gypsum.

Further, the gypsum seed crystal is alpha high-strength gypsum dry powder.

Further, drying and grinding the alpha high-strength gypsum prepared in the step (4) to obtain alpha high-strength gypsum dry powder, and using the prepared alpha high-strength gypsum dry powder as gypsum crystal seeds.

In the primary production, commercially purchased alpha high-strength gypsum dry powder is used as gypsum seed crystal; after the alpha high-strength gypsum finished product is prepared, alpha high-strength gypsum dry powder obtained by drying and grinding the alpha high-strength gypsum prepared in the step (4) is used as gypsum seed crystal, so that the cost of the gypsum seed crystal can be effectively reduced.

Furthermore, the addition amount of the gypsum seed crystal is 10 to 15 percent (w/w) of the weight of the byproduct gypsum in the raw material industry; the addition amount of the mordant is 0.05-0.15% (w/w) of the weight of the byproduct gypsum in the raw material industry.

Further, the mordant is a composition obtained by mixing industrial salts and organic acid according to the weight ratio of 1: 1.

Preferably, the mordant is a composition obtained by mixing aluminum sulfate and citric acid in a weight ratio of 1: 1.

Further, the industrial by-product gypsum is one or more of phosphogypsum, desulfurized gypsum and titanium gypsum.

Further, when the industrial by-product gypsum contains phosphogypsum, a modifier needs to be added into the industrial by-product gypsum, wherein the addition amount of the modifier is 1-3% of the weight of the phosphogypsum.

Further, the modifier is calcium oxide powder.

Further, the external water generated by the wet-heat dehydration reaction in the step (4) is recycled as the water for the step (1) and the step (3).

Compared with the prior art, the invention has the following beneficial effects:

(1) in the process of preparing the alpha high-strength gypsum, the industrial byproduct gypsum raw material is in a semi-dry plastic state, namely, the moisture content in the raw material is reduced, and the wet-heat dehydration reaction time is favorably shortened, so that the steam consumption is saved, and the energy consumption is reduced.

(2) In the process of preparing the alpha high-strength gypsum, the discharged water generated in the wet and hot dehydration process is recycled in the process, so that the recycling of water resources is facilitated, and simultaneously, the discharge of waste water is effectively avoided, so that the process has the advantages of environmental friendliness and energy conservation.

(3) The process for preparing the alpha high-strength gypsum has the advantages of low production energy consumption, relatively simple process, utilization of waste materials, resource saving, environmental protection, good product performance and high strength, and is very suitable for the development needs of future assembly type buildings and novel gypsum building materials.

Drawings

FIG. 1 is a schematic diagram of the preparation process of the present invention.

Detailed Description