NEWS
08
2020
-
12
Diamond saw blade on the stone three major impact can not be ignored
1. Stone mining technology and equipment
At present, there are still many stone mines in China that use the backward method of drilling and blasting to produce stone blocks, which is not only low in production efficiency but also unsafe in operation. In particular, due to the rupture of rock mass caused by blasting, the stone resources are seriously damaged, the size of the blocks produced is irregular, even scrapped due to cracks, and the yield is very low. It is estimated that only 5% to 8% of the mining volume of waste materials can be processed into timber by drilling and blasting. In the early 1980 s, some developed countries in the stone industry have banned the use of explosive blasting methods to mine stone, and replaced them with advanced technologies such as diamond bead wire saws. It can be said that this is a symbol of the modernization of stone mining technology. An important indicator to measure the modernization of stone mining technology is the number of cubic meters of raw materials per capita per day. The industry believes that China's stone mines are low productivity. The reasons are lack of mechanized equipment, backward mining technology and poor production management. The average annual mining volume of some stone mines is only a few hundred to a few thousand cubic meters, and the annual mining volume of a few stone mines is more than 10000 cubic meters, and the annual per capita output is 6 m3.. The average monthly output per capita is only 0.5 m3, which is lower than that of India. As we all know, India is also a big stone producer. But its granite mine is small and has no modern equipment, so the productivity of stone blocks is very low. The daily average is only 1 m3. Finland is the largest exporter of stone among the Scandinavian countries. Its granite mine production system is world-class, exporting at least 250000 tons of granite every year, and the mine production efficiency is as high as 40m3 per capita per day. The productivity of South African stone mines is medium, with a daily average of 8-10m3 per capita.
2. Stone processing machinery and equipment
In the past ten years, the development of China's stone machinery and equipment has made great progress, and some stand-alone performance automation has reached the international advanced level. However, in terms of high-end technical equipment, China has not yet produced. From the stone enterprise overall production line automation, compared with foreign countries there is still a gap, some production links still rely on human operation, not only affects the production efficiency, but also because of the quality of staff is not high resulting in the quality of the finished product there are unstable factors. Even if most of the stone companies in Italy use highly automated production lines, they still need to have a certain amount of stone knowledge and experienced personnel to master the process parameters of the processing process in order to produce top stone products.
At present, many foreign stone mines, especially granite mines have fully adopted diamond bead wire saw to mine blocks, and in the sawing processing of granite blocks, multi-line diamond bead wire saw has also been promoted. However, many stone companies in China still use old-fashioned frame saws. One of its significant advantages is the lower cost of sawing, but there are many disadvantages:
The assembly cost is high, about four times that of the diamond beaded rope saw;
There are many operators, at least two people are required to operate. More people need to work together when replacing the saw blade;
The sawing speed is slow, and the sawing speed of the old frame saw is only 2 cm/h. The sawing speed of the new frame is also only 3.5-3.8 cm/h. The cutting speed of diamond bead wire saw is as high as 20 cm/h, which may be increased to 30 cm/h;
④ The surface of the plate sawn by the frame saw is rough and the flatness is poor, so the polishing speed is low, which is 100 cm/min, while the surface of the plate sawn by the diamond bead rope saw is smooth, and the polishing speed can be as high as 160 cm/min, thus reducing the polishing time;
⑤ Energy consumption and material consumption are relatively high;
The disposal of scrap steel mortar and dust in the workplace cause serious environmental pollution.
3. Quality of finished stone products
The international stone industry believes that the quality of China's finished stone products is not high because the stone processing equipment and process methods used are lagging behind other countries. Take the production of granite facing tiles as an example. Granite blocks mined from mines are mostly irregular in shape and of different sizes. Diamond circular saw blades with diameters of 1m and 1.6m are generally used for sawing into granite plates. The quality of the saw blades is not high. The sawn plates are usually polished and polished with rocker arms. The processing is mostly handicraft operation, I .e. grinding machines with high degree of automation are used, and the abrasive used for matching grinding heads is of poor quality. The polished plate is cut into a certain size with an ordinary cross cutting machine, low degree of automation in the production process. In the 1990 s, many European countries have adopted advanced sawing machines and high-quality saw blades. The production of granite tiles is almost fully automated. The latest generation of sawing machines are equipped with up to 80 diamond circular saw blades with a diameter of 1m. Due to the use of high-quality diamonds, the linear speed of the saw blade can be as high as 35 m/s, the feed speed is 17 m/min, and the cutting rate of each saw blade is 1m2/h. In contrast, the sawing machine used in China is generally equipped with only five saw blades with a diameter of 1m or 1.6m, and the quality of the saw blade matrix and diamond is poor, so the linear speed of the saw blade is limited to 17 m/s or 27 m/s, and the feed speed is slow, with a sawing rate of 5 m/min per saw blade of about/0.3 m2/h.
