Study on the ratio of desulfurization gypsum in fly ash bricks.
I. Introduction. With the rapid development of industrialization, the generation of large amounts of waste such as fly ash and desulfurization gypsum has caused double pressure on the environment and resources. How to effectively use these wastes to reduce the burden on the environment and create economic value is an important issue facing the field of contemporary scientific research and engineering. As a new type of building material, the ratio of desulfurized gypsum in the production process of fly ash brick has an important impact on the performance and quality of the product. In this paper, the ratio of desulfurization gypsum in fly ash bricks will be studied in depth, in order to provide theoretical support for the practice in related fields.
2. Overview of fly ash and desulfurization gypsum.
Fly ash: It is the main solid waste emitted by coal-fired power plants, containing a large amount of silicon, aluminum and other oxides, and has a certain gelatinity. The emission of fly ash is large, the utilization rate is low, and the accumulation of a large amount not only occupies land, but also causes harm to the environment and human health.
Desulfurization gypsum: It is an industrial by-product produced in the process of flue gas desulfurization, and the main component is calcium sulfate. Desulfurization gypsum has a certain hydraulicness and can be used as a building material. However, due to its large production and low utilization rate, the treatment and disposal of desulfurization gypsum is also an urgent problem to be solved.
3. The role of desulfurization gypsum in fly ash bricks.
In the production process of fly ash bricks, the addition of desulfurization gypsum can play the following roles:
Improve the mechanical properties of the brick: The desulfurization gypsum reacts with the active ingredients in the fly ash to form hydration products with hydraulic hardness, thereby improving the strength and hardness of the bricks.
Promote the densification of the brick structure: the addition of desulfurization gypsum can fill the pores inside the brick, reduce the water absorption rate of the brick, and improve the durability of the brick.
Adjust the drying shrinkage of bricks: The addition of desulfurization gypsum can adjust the drying shrinkage of bricks and reduce the cracking phenomenon of bricks during the drying process.
Fourth, the experimental design of desulfurization gypsum ratio.
In order to study the optimal ratio of desulfurization gypsum in fly ash bricks, a series of experiments were designed. In the experiment, fly ash was used as the main raw material, and different proportions of desulfurization gypsum (such as %, etc.) were added to prepare fly ash brick samples with different proportions. Then, the mechanical properties (such as compressive resistance, flexural strength, etc.), durability (such as water absorption, acid and alkali resistance, etc.) and microstructure of the sample were observed and analyzed.
5. Experimental results and analysis.
Through the statistics and analysis of the experimental data of fly ash brick samples with different ratios, the following conclusions can be obtained:
With the increase of the proportion of desulfurization gypsum, the compressive and flexural strength of fly ash bricks first increases and then decreases, and there is an optimal ratio to make the strength of the bricks reach the maximum value.
The addition of desulfurization gypsum can reduce the water absorption rate of fly ash bricks and improve the durability of bricks. However, too high desulfurization gypsum ratio will lead to loose internal structure of bricks, and the water absorption rate will increase.
Through the observation of microstructure, it is found that an appropriate amount of desulfurization gypsum can fully react with the active ingredients in fly ash to form dense hydration products. Excessive or insufficient desulfurization gypsum will lead to insufficient hydration reaction and affect the performance of the brick.
6. Conclusions and prospects.
In this paper, through the study of the proportion of desulfurization gypsum in fly ash bricks, it is found that the mechanical properties and durability of fly ash bricks can be significantly improved by adding desulfurization gypsum in an appropriate amount. However, excessive or insufficient desulfurization gypsum can have a negative impact on brick performance. Therefore, in the actual production process, it is necessary to determine the optimal ratio of desulfurization gypsum according to the properties of raw materials and process conditions. In the future, with the continuous progress of science and technology and the increasing requirements of environmental protection, it is believed that the production technology of fly ash bricks will continue to innovate and develop, and make greater contributions to the sustainable development of the construction industry. At the same time, the treatment and disposal of desulfurization gypsum also need to further strengthen research and application, explore its utilization value in more fields, and maximize the utilization of resources and environmental protection.