阅读说明：本技术 一种液体模板法赤泥/土壤水泥多孔复合材料的制备及应用 (Preparation and application of red mud/soil cement porous composite material by liquid template method ) 是由 武世宏 孙玉梅 迟明梅 王佐兵 赵金杰 董云云 史春丽 陈祥光 于 2020-05-12 设计创作，主要内容包括：本发明涉及固体废物综合利用领域,是一种采用液体模板法制备赤泥/土壤水泥多孔复合材料的技术,并探讨了其应用。本发明着眼于经济低碳的液体模板成孔免烧技术,主要利用赤泥、氧化镁及磷酸类肥料制备了性能较好的多孔复合材料,并且强化了重金属离子的固化作用,避免环境的污染,所述多孔复合材料包括按质量百分比计的以下成分,赤泥30~70份,轻烧氧化镁30-70份,辐射消减剂5~15份,缓凝剂3~20份,水为20-70份,强化纤维3-10份,强化骨料5-20份。据本发明所述方法制备的赤泥/土壤水泥免烧多孔复合材料,具有生产成本低,低碳环保等特点,该赤泥/土壤水泥多孔复合材料有望应用于道桥工程、海岸防护工程、河道治理工程、人行步道铺装以及其他的建筑工程方面。(The invention relates to the field of comprehensive utilization of solid wastes, in particular to a technology for preparing a red mud/soil cement porous composite material by adopting a liquid template method, and discusses the application of the red mud/soil cement porous composite material. The invention aims at an economical low-carbon liquid template pore-forming baking-free technology, and mainly utilizes red mud, magnesium oxide and phosphoric acid fertilizers to prepare a porous composite material with better performance, strengthens the curing effect of heavy metal ions, and avoids environmental pollution, wherein the porous composite material comprises the following components, by mass, 30-70 parts of red mud, 30-70 parts of light-burned magnesium oxide, 5-15 parts of a radiation reduction agent, 3-20 parts of a retarder, 20-70 parts of water, 3-10 parts of reinforcing fibers and 5-20 parts of reinforcing aggregates. The red mud/soil cement baking-free porous composite material prepared by the method has the characteristics of low production cost, low carbon, environmental protection and the like, and is expected to be applied to road and bridge engineering, coast protection engineering, river treatment engineering, pavement of sidewalks and other construction engineering.)

1. The preparation and application of the red mud/soil cement porous composite material by the liquid template method are characterized in that: comprises the soil cement which uses the solid waste generated by producing alumina, namely red mud, and active light burned magnesia which is prepared by sintering magnesite tailings as raw materials as main components, a retarder, a strengthening phase and independent surface strengthening and coloring process technologies and methods.

2. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 1 are characterized in that: the red mud is solid waste generated in the process of producing alumina by a Bayer process, a sintering process and a combination process,

the granularity of the red mud is not less than 200 meshes.

3. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 2 are characterized in that: the active light calcined magnesia or magnesia powder is prepared by calcining, crushing and grinding magnesite tailings at 1000 ℃ under 800-.

4. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 3 are characterized in that: the exciting agent is dihydrogen phosphate such as ammonium dihydrogen phosphate and potassium dihydrogen phosphate.

5. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 4 are characterized in that: the retarder is one or a mixture of more than two of boric acid, citric acid, borax, triethanolamine, sodium borate, boric sludge (solid waste generated during boric acid production) and alkali metal salts.

6. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 5 are characterized in that: the reinforcing phase is inorganic fiber, rock wool, glass wool, ceramic fiber, glass fiber, slag wool, organic fiber and organic and inorganic aggregate (containing unwashed sea sand), and in addition, a proper amount of barium salt needs to be added for the industrial requirement with the radioactive index requirement.

7. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 6 are characterized in that: the liquid template method is a more environment-friendly water system template method.

8. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 7 are characterized in that: the drying process of the red mud/soil cement porous composite material comprises forming, curing for not less than 7 days, and natural drying or forced drying.

9. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 8 are characterized in that: the surface strengthening or coloring process adopts an immersion process technology, and comprises the steps of using cement slurry, geopolymer slurry, organic silicon solution, water glass solution and the above various slurries added with dyes.

10. The preparation and application of the liquid template method red mud/soil cement porous composite material according to claim 8 are characterized in that: the red mud/soil cement porous composite material is expected to be applied to heat-insulating materials, noise-reducing partition materials, highway subgrade materials, pavement of sidewalks and supporting materials of permeable bricks.

The technical field is as follows:

the invention belongs to the technical field of comprehensive treatment of solid wastes, and relates to a red mud/soil cement porous composite material prepared by a liquid template method and application thereof. The reasonable liquid template method is used without using pore-forming agents, is more economical and environment-friendly, and utilizes the good bonding property of soil cement and the reasonable addition of strengthening phases, thereby obtaining the composite material capable of meeting the requirements of different industries.

Background art:

the red mud is solid waste generated in the process of extracting aluminum oxide in the aluminum production industry, the main chemical components of the red mud are ferric oxide, aluminum oxide, silicon dioxide, calcium oxide and the like, the red mud is rich in silicon and aluminum elements, and the red mud belongs to high-alkali waste residues. A large amount of piled up for a long time not only occupies land resources but also causes huge burden to the environment, and the comprehensive utilization of the red mud becomes a worldwide problem. Based on this, effective red mud resource utilization ways are explored by combining the composition characteristics of the red mud, the common attention of scholars at home and abroad is attracted, and the achievements are achieved in the fields of utilizing the red mud to fire building materials, preparing permeable bricks by two-step mixed firing of the red mud/glass powder, preparing red mud/phosphogypsum roadbed materials, utilizing the red mud to fire cement, extracting valuable metals from the red mud and the like. However, in most of these cellular foamed materials, a foaming agent is used, and the use of the foaming agent not only increases the cost but also imposes an additional burden on the environment, and the economical efficiency and environmental friendliness are yet to be further improved. For example: these are described in the documents CN201911262860.1, CN201911203183.6, CN201911111135.4, CN201911111155.1, and CN201911136174. x.

The invention content is as follows:

the invention relates to a red mud/soil cement porous composite material prepared by adopting a liquid template method and application thereof, which aims at the economical low-carbon liquid template pore-forming baking-free technology, and utilizes hydrous red mud, sintered magnesite tailing ore, an excitant and a retarder to obtain the porous composite material which has low production cost and good strength and can meet the requirements of several industries, thereby having certain innovative significance and engineering practical value and certain market prospect. It is known that red mud has a certain heavy metal ion adsorption effect but certain fluidity. The invention utilizes the strong curing effect and cementing effect of heavy metal ions (except chromium metal ions) of the active magnesium oxide in the phosphorus-magnesium cement to further ensure the effective curing of the heavy metals and avoid the pollution to the environment, so the material prepared by the invention is expected to be applied to heat insulation materials, noise reduction partition materials, highway subgrade materials, pavement of sidewalks and supporting materials of water permeable bricks.

Description of the drawings:

FIG. 1 is a graphical representation of the porosity, bulk density and compressive strength of a sample. The test result shows that the water consumption and the porosity as well as the water consumption and the compression strength basically have a linear relationship, namely, the water consumption is large, the porosity is high, the density is low, and the strength is low; small water consumption, low porosity, high density and high compression strength. In addition, the fibers and sea sand as the reinforcing phase exert their respective reinforcing effects on the bending strength and the compressive strength.

The specific implementation mode is as follows:

the invention relates to a technology for preparing a red mud/soil cement porous composite material by adopting a liquid template method, which comprises the following experimental steps: the experiment of the invention uses Bayer process red mud from the aluminum industry of the Nanshan of the tobacco station, the water content is about 30 percent (dry red mud with the water content of below 5 percent can be used, but no caking is required), light-burned magnesia in soil cement is from Hua Mg group in the great Qiaoqiao city, the excitant is a mixture of monopotassium phosphate and monoammonium phosphate for fertilizer, the retarder is test-grade boric acid, and alumina fiber is from Jia Hua group in Zhejiang, which are raw materials of the experiment. The components are respectively as follows: 30-70 parts of red mud, 30-70 parts of light-burned magnesium oxide, 3-20 parts of an activator, 1-20 parts of a retarder, 20-70 parts of water, 3-10 parts of reinforcing fibers and 5-20 parts of reinforcing aggregates.