Different Sand Processing Plant cases
In the sandstone processing system of Xinyuanggou of Ahai Hydropower Station, high strength limestone is used to make sand, and the dry sand making process is adopted. The wool separation workshop is set up in the coarse crushing workshop, which not only reduces the content of finished sand and stone powder, but also avoids the possibility of muddy powder in finished sand. Dry sand making is adopted to avoid the difficulty of water treatment and the problem of stone powder recovery.
The representative projects of wet sand making are the sandstone system of the lower bank of the Three Gorges, the sandstone system of the Xiluodu central yard and the sandstone system of the Yagongxi in Pengshui. Their technological process features are as follows: vertical shaft impact crusher and inspection screen fractal into a closed cycle, inspection screen set up 3 mm, 5 mm and part of 5-40 mm screen mesh, 3 mm below particles and rod mill products after classification, dehydration directly into the finished product sand bin, 3-5 mm particles into the rod mill above 5 mm particles back to the vertical shaft impact crusher. The combined sand-making technology of vertical impact crusher and bar mill is adopted in the artificial sand-stone system of Xiabanxi of the Three Gorges Project, which pioneered this kind of artificial sand-making technology in China, pushed the research and application of artificial sand-making technology to a new height, and made a positive contribution to the hydropower construction in China.
The sand and stone processing system of Pengshui Hydropower Station adopts the wet sand processing technology. In order to solve the problem of insufficient sand and stone powder caused by the loss of some stone powder in the process of sand and water separation by spiral sand washing machine, the stone powder recovery process is designed. Two sets of 2E48-120W-4A fine sand recovery equipment of Company are adopted.
The sand and stone system of Taishan Nuclear Power Plant is divided into 0~3mm and 3~5mm by the crushing and grading technology of "breaking instead of grinding + high frequency screening". According to the requirement of fineness modulus, the mixing capacity of 3~5mm is adjusted. The sand is pumped by fan and then washed partially to adjust the content of stone powder so as to ensure the finished sand. The quality is excellent. The excess coarse sand of 3-5mm was produced by breaking instead of grinding and high-frequency sieve, and then the sand was made by bar grinding machine. Sands produced by breaking instead of grinding + high frequency screening and bar grinding are respectively fed into the adjusting silo of human sand. Both of the two kinds of sand can be produced as qualified high quality sand and then fed into the finished sand silo after being adjusted. After adjusting the fineness of finished sand by triple process, the gradation continuity is better, the moisture content is easy to control, and the quality is more guaranteed.
Aiming at the characteristics of limestone, the design of artificial sand aggregate system of Suofengying Hydropower Station adopts the semi-dry sand-making technology of vertical-axis sand-making machine "replacing grinding by breaking". Combining the recycling of silt and water with the environmental protection project, the air pollution caused by dust is eliminated and a green sand-stone production system is established.
The semi dry sand making technology is adopted in Sujia River Estuary hydropower station, which is broken by three stages: coarse, medium and fine. Open crushing is used for coarse crushing and fine crushing, and closed cycle production technology is adopted in the middle crushing and corresponding screening workshop. Medium crushing adopts adjusting the opening of discharge port, fine crushing adopts adjusting speed and other methods to meet the production requirements of various particle size gradations.
A good production process must fully consider the material properties, process rationality, reliability, advanced, economic and mutual matching. In addition, the development of automatic control system in line with the production scale, in order to meet the requirements of environmental protection under the premise of a low-carbon green development path, is the future development trend of sand production. Moreover, we also need to absorb a large number of advanced experience and technology from the same industry at home and abroad, and finally integrate the advantages of the system to develop a production model of machine-made sand suitable for the target project.