Discussion on continuous extrusion molding of dry gypsum
Application of Technology
Pan Xiumei and Xu fangkao
(Wenzhou Wengong Construction Machinery Co., Ltd., Wenzhou 325000, Zhejiang)
Abstract: At present, the industrial by-product gypsum has been widely used in China, while the gypsum mortar wallboard and related products are still produced by the inherent natural drying method and drying method after molding. This paper expounds the characteristics, functions and effects of the semi dry gypsum continuous extrusion molding technology, with the purpose of accelerating the comprehensive utilization of industrial by-product gypsum and the innovation of processing technology, promoting energy conservation and emission reduction, Promote the recycling and utilization of industrial wastes more extensively, effectively improve the production process of gypsum wallboards and products, and realize the popularization and application of semi dry gypsum continuous extrusion molding technology.
Keywords: industrial by-product gypsum; Semi dry gypsum extrusion molding; Gypsum wallboard; Social and economic benefits
(1) Introduction
The so-called "dry gypsum continuous extrusion molding technology" refers to a dry gypsum continuous extrusion molding equipment with multiple functions to rapidly produce various industrial by-products by replacing various supporting molds, such as round hole hollow wallboard, square hole hollow wallboard, solid core strip, curb, and special-shaped strip.
This technology can adapt to the continuous extrusion molding products of cement mixture and dry gypsum mixture, and is a major breakthrough in the utilization technology of industrial by-product gypsum, with small investment, fast production, strong practicability and obvious effect.
(2) Application significance
2.1 Dry gypsum continuous extrusion molding technology has emerged in recent years for the effective utilization of industrial by-product gypsum. Due to the continuous promotion and intensification of the national environmental pollution control policy, and the emphasis on the comprehensive utilization of industrial by-product gypsum, slag, tailings and other solid wastes, and the requirement to speed up the reliance on scientific and technological innovation, as well as the increasingly strengthening of environmental pollution control measures by local governments, the comprehensive utilization of industrial wastes and industrial by-product gypsum is constantly introducing new policies, The corresponding mechanical equipment and technology for the continuous extrusion molding of dry gypsum are gradually mature. It has been realized that it is suitable for both the cement mixture extrusion molding products and the continuous extrusion production of dry gypsum wallboard and other products. It not only has high production efficiency and large output, but also plays an important role in digesting industrial wastes and industrial by-product gypsum.
2.2 The dry gypsum extrusion molding technology adopts the continuous extrusion production process and has many advantages. Because the traditional gypsum products are mostly produced by pouring method, the products contain a lot of natural water, and the drying takes a long time. Drying increases the production cost of the products. The moisture content of the products produced by dry gypsum extrusion molding technology can be less than 12%, which fully meets the relevant standard conditions. After the hydration of gypsum, it can be delivered without drying, which greatly shortens the product production cycle and reduces the product production cost. In particular, the coastal and central and southern regions of China have high air humidity, which is more suitable for dry production process.
2.3 According to the distribution of resources in China, the industrial by-product gypsum in the central and southern regions of China has a large output, a considerable historical accumulation, and the air humidity in the region is high. Therefore, the traditional casting method production process is adopted. The products rely on long-term natural drying or drying, and the dry method production process is more suitable. In addition, the environmental protection and environmental management in the central and southern regions has been strengthened day by day, and the support and preferential policies have also been increased accordingly, which is more conducive to the application of semi dry gypsum extrusion technology, and has opened up a new way to make full use of industrial by-product gypsum, thus stepping on a fast track to promote the comprehensive utilization of industrial by-product gypsum.
2.4 The production line technology of continuous extrusion molding is a new process adopted for the mixture and dry gypsum, which aims to meet the theoretical water consumption of gypsum hydration reaction, that is, to ensure the water consumption of gypsum hydration. The water paste ratio used is small, and the free water of the product is less than 12% within 2 hours after the test hydration is completed. The main indexes such as compression and bending resistance measured in the test can meet the technical requirements of GB / t23451-2009, light partition board (gypsum) for buildings.
3 Dry gypsum extrusion molding machine is the core of dry gypsum extrusion molding process and has the following characteristics:
3.1 Strong material adaptability: It can adapt to cement mixture, industrial by-product gypsum mixture, solid waste mixture (fly ash, slag, tailings, gypsum, cement), etc.
3.2 Structure form: Double thread feather wing balanced extrusion screw pair is the key technology.
3.3 production products: Gypsum light hollow slats, solid slats, kerbs, road slope protection bricks, light wall panel cushion blocks, etc. the main machine is unchanged, and multi variety production can be realized only by replacing the supporting mold.
3.4 Output design: Taking gypsum lightweight hollow slats as an example, the annual output of a single production line can reach 500000-700000 square meters, which obviously has considerable economic benefits.
3.5 Policy support: At present, the state has strengthened the management of environmental pollution control, especially the impact of industrial by-product gypsum and solid waste on the environment. This technology conforms to the current national policy, and the government supports and rewards policies are favorable.
3.6 Process flow diagram:
4 Technical indicators: Adopt semi dry gypsum molding technology and measure the actual technical parameters of the product
Impact resistance: there is no crack on the plate surface after 5 impact tests.
Bending bearing capacity (plate dead weight multiple): 1.5 times
Compressive strength / MPA: ≥ 3.5
Softening coefficient: waterproof ≥ 0.6, ordinary ≥ 0.4
Surface density / kg / ㎡: plate thickness 90mm ≤ 90kg / m2, plate thickness 120 ≤ 100kg / m2
The hollow ratio can be controlled within the range of 35% - 39%.
Water content: < 12%
Drying shrinkage value: 0.6mm
Air sound insulation loss / DB: 90mm ≥ 35dB, 120mm ≥ 45dB.
Refractory pole ≥ Grade A.
5 Conclusion:
The application of dry gypsum extrusion molding technology is beneficial to the country and the people, and the investment can save 40% - 70% compared with the current production technology of various plates in the market, with significant economic and social benefits. It is a breakthrough in the comprehensive utilization of industrial wastes, and it also promotes the quality and efficiency of the comprehensive utilization technology of industrial by-product gypsum. At the same time, it is of great significance for energy conservation and emission reduction, benefiting mankind, beautifying the environment.
(author's telephone: 13758453902 15855179852)
