阅读说明：本技术 一种将硅质尾料蒸汽水热为高强度建筑材料的方法 (method for hydrothermal preparation of high-strength building material from siliceous tailings by steam ) 是由 郦怡 景镇子 成铭钊 于 2019-09-11 设计创作，主要内容包括：本发明涉及一种将硅质尾料蒸汽水热为高强度建筑材料的方法,先按照质量百分比量取硅质尾料：钙质添加剂：活性激发剂：水＝50％～80％：10％～30％：0.5％～5％：5～15％,混合均匀,压制成型得建筑材料型材生坯。生坯脱模后在110℃～170℃下热压处理8～24h,而后在常温高湿度环境下养护6～12h,成为建筑材料产品；经过检测,其抗压强度能达到25～50MPa。本发明实现了玻璃、陶瓷和机制砂生产过程中产生的尾砂尾泥、陶瓷废料和洗沙底泥为代表的硅质尾料地高效再利用,实现了固体废弃物资源化利用,合成的固化体材料具有较高强度,可用作墙砖、地砖、广场砖、步道砖、透水砖、人工鱼礁和海洋江河护堤材料、挡墙材料等。(The invention relates to a method for hydrothermal preparation of a siliceous tailings into a high-strength building material, which comprises the following steps of: calcium additive: an activity activator: 50-80% of water: 10% -30%: 0.5% -5%: 5-15%, uniformly mixing, and pressing and forming to obtain the building material profile green body. Demoulding the green body, carrying out hot pressing treatment for 8-24 h at 110-170 ℃, and then curing for 6-12 h in a normal-temperature high-humidity environment to obtain a building material product; through detection, the compressive strength of the material can reach 25-50 MPa. The invention realizes the high-efficiency reutilization of siliceous tailings represented by tailing, waste ceramic and sand washing bottom mud generated in the production process of glass, ceramics and machine-made sand, realizes the resource utilization of solid wastes, and the synthesized solidified material has higher strength and can be used as wall bricks, floor tiles, square bricks, pavement bricks, permeable bricks, artificial fish reefs, ocean river bank protection materials, retaining wall materials and the like.)

1. a method for hydrothermal preparation of high-strength building material from siliceous tailings is characterized by comprising the following steps: firstly, weighing silicon tailings according to mass percentage: calcium additive: an activity activator: 50-80% of water: 10% -30%: 0.5% -5%: 5-15%, uniformly mixing, and pressing and forming to obtain a building material profile green body; after demolding, carrying out hot pressing treatment for 8-24 h at 110-170 ℃, and then curing for 6-12 h in a normal-temperature high-humidity environment to obtain a building material product; through detection, the compressive strength of the material can reach 25-50 MPa;

The siliceous tailings are tailings and tailings generated in the glass production process; ceramic defective products, waste ceramic powder and ceramic polished tile waste materials generated in the ceramic production process; one or more siliceous tailings formed by mixing sand washing bottom mud in any proportion in the production process of machine-made sand;

The calcareous additive is a commercial industrial grade commodity which is prepared by mixing one or more of slaked lime, limestone, quicklime, dolomite and calcium-containing inorganic waste according to any proportion;

The active excitant is a self-made product and is prepared by weighing 15-25 parts of sodium silicate according to the weight ratio; 5-30 parts of sodium hydroxide; 5-35 parts of soda ash; 10-30 parts of desulfurized gypsum and 10-55 parts of C-S-H seed crystal are uniformly mixed to obtain a powdery medicament with the particle size of 100 meshes;

The C-S-H seed crystal in the activity excitant is prepared according to the following method: weighing amorphous silica/quicklime 1.5-1.7 in mass ratio, uniformly mixing, then putting into a mechanical stirring reaction kettle, adding water which is 9-12 times of the total mass of the mixture into the reaction kettle, reacting for 4-10 hours at the temperature of 120-160 ℃, and then filtering, vacuum drying, grinding and sieving with a 100-mesh sieve to obtain the C-S-H crystal seed.

2. The method of claim 1 for steam hydrothermal conversion of siliceous tailings into high strength building materials, comprising: the high-strength building material is a building material profile product for wall bricks, floor tiles, square bricks, pavement bricks, permeable bricks, artificial fish reefs, ocean river bank protection materials and retaining wall materials.

Technical Field

The invention relates to a method for hydrothermal preparation of a high-strength building material from siliceous tailings, belonging to the technical field of resource recycling of solid wastes.

Background

The siliceous tailings are defined as industrial tailings with silicon dioxide content of more than 50%, and are general solid wastes generated in the industrial production process, specifically include tailings generated in the glass production process, ceramic wastes generated in the ceramic production process, sand washing bottom mud generated in the machine-made sand production process, and the like. With the rapid development of economic and industrial production in China, the quantity of siliceous tailings is increased explosively. However, the wastes with huge amount, various kinds and complex components are only treated in a rough yard or simple landfill mode, which causes great harm to the production and life of people, but the research on the reutilization of the siliceous tailings in the domestic and foreign documents is less, and the treatment mode in the actual industry is mainly landfill or stacking. How to continuously promote the resource utilization of the siliceous tailings, reduce the landfill capacity to the maximum extent, change the siliceous tailings into a utilizable 'urban mineral product', and become the focus of attention in the field.

Disclosure of Invention

The invention aims to provide a method for hydrothermal preparation of siliceous tailings into a high-strength building material, which fills the domestic blank of research on utilization of the wastes. The novel building material prepared by the invention has the strength far higher than that of common cement concrete building materials, has better durability, and can be widely applied to the aspects of road pavement, building materials, river bank protection retaining walls and the like.

in order to achieve the purpose, the method adopted by the invention is steam hydrothermal, which is a method for rapidly reproducing the long-growing rock-forming process of the natural rock pile in a laboratory, namely, the raw material is placed in a water vapor environment with certain temperature and pressure, and the water in the steam environment is in a supercritical state, so that the dissolving capacity and the reaction activity are greatly enhanced. By the method, siliceous tailings which are difficult to react under the conditions of normal temperature and normal pressure participate in a reaction system, and react with a calcareous additive under the action of an active excitant to generate new crystals so as to improve the strength. The new crystals are in fiber or sheet shape, are interwoven with each other and are filled in the gaps of the raw materials, and play a crucial role in the final improvement of the strength.

The method comprises the following specific steps:

Weighing silicon tailings according to mass percent: calcium additive: an activity activator: water (50-80%): (10-30%): (0.5-5%): (5-15%), uniformly mixing, and pressing and forming to obtain a building material profile green body; after demolding, carrying out hot pressing treatment for 8-24 h at 110-170 ℃, and then curing for 6-12 h in a normal-temperature high-humidity environment to obtain a building material product; through detection, the compressive strength of the material can reach 25-50 MPa.

The siliceous tailings are tailings and tailings generated in the glass production process; ceramic defective products, waste ceramic powder and ceramic polished tile waste materials generated in the ceramic production process; one kind of sand washing bottom mud or a plurality of kinds of silicon tailings mixed according to any proportion in the production process of machine-made sand.

The calcareous additive is one or more of slaked lime, limestone, quicklime and dolomite which are mixed according to any proportion and are sold in commercial industrial grade products.

The activity excitant is a self-made product and is prepared by weighing 15-25 parts of sodium silicate according to parts by weight; 5-30 parts of sodium hydroxide; 5-35 parts of soda ash; 10-30 parts of desulfurized gypsum and 10-55 parts of C-S-H seed crystal are uniformly mixed to obtain a powdery medicament with the particle size of 100 meshes.

The C-S-H seed crystal in the activity excitant is prepared according to the following method: weighing amorphous silica/quicklime 1.5-1.7 in mass ratio, uniformly mixing, then putting into a mechanical stirring reaction kettle, adding water which is 9-12 times of the total mass of the mixture into the reaction kettle, reacting for 4-10 hours at the temperature of 120-160 ℃, and then filtering, vacuum drying, grinding and sieving with a 100-mesh sieve to obtain the C-S-H crystal seed.

The invention has the advantages and effects that:

1. The doping amount of the siliceous tailings reaches 50-80%, the siliceous tailings which are difficult to treat are used as main reaction raw materials for treatment, and compared with the addition amount of less than 30% of siliceous tailings used as fillers in the traditional technology, the method is an efficient method for recycling solid wastes.

2. the invention adopts a steam hydrothermal treatment mode, the reaction temperature is not more than 170 ℃, and compared with the traditional sintering mode, the energy consumption is lower, the energy is saved, the environment is protected, and no secondary pollution is generated.

3. The waste siliceous tailings can be prepared into high-strength building materials by utilizing the method, can be widely used as wall bricks, floor tiles, square bricks, pavement bricks, embankment protection materials, retaining wall materials and the like, and really realizes the high value-added utilization of the siliceous tailings. Meanwhile, the silicon raw material has high mixing amount and low energy consumption at reaction temperature, so that the product has low production cost and strong market competitiveness.

Drawings

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

FIG. 2 is a graph showing the effect of calcareous additive content of the present invention on the flexural strength of a siliceous tailings steam hydrothermal building material product.

FIG. 3 is a graph of the infrared profile of a building material product at various calcareous additive levels according to the present invention.

Detailed Description

The invention is further illustrated by the following examples.

Firstly, preparing an activity excitant: 20 parts of sodium silicate measured according to the weight ratio; 10 parts of sodium hydroxide; 15 parts of soda ash; 15 parts of desulfurized gypsum and 40 parts of C-S-H seed crystal are uniformly mixed to obtain a powdery medicament with the particle size of 100 meshes. The sodium silicate, the sodium hydroxide, the soda ash and the desulfurized gypsum are all commercial products.

The C-S-H crystal seed in the active excitant is prepared by taking amorphous silica and quicklime as raw materials, weighing the amorphous silica/quicklime to be 1.5 according to the mass ratio, uniformly mixing, then putting into a mechanical stirring reaction kettle, adding water which is 10 times of the total weight of the raw materials into the reaction kettle, stirring and reacting for 5 hours at the temperature of 140 ℃, and then filtering, vacuum drying, grinding and sieving with a 100-mesh sieve to obtain the C-S-H crystal seed.