Development history of magnesium metal in China
Magnesium metal is a new light corrosion resistant metal material developed in the twentieth century, the application of magnesium metal is mainly concentrated in magnesium alloy production, aluminum alloy production, steel desulfurization, aviation and military four fields, widely used in automobile manufacturing, light industry, metallurgy, chemical industry, electronic industry and instrument manufacturing. Magnesium alloy's excellent performance and beautiful posture are favored by computer, home appliances, mobile phones and other manufacturers. It has the advantages of low specific gravity, high strength per unit weight and high chemical stability, so that aluminum magnesium alloy and its magnesium die casting are popular, and the magnesium industry has developed rapidly. Magnesium alloy has the advantages of high strength, heat resistance, wear resistance and light weight, making it gradually replace plastic products and heavy steel parts in the automobile industry, mainly replacing the original engine, steering wheel, seat base and so on. General Motors, for example, has 15 pounds (6.8 kilograms) of magnesium molded parts in its Polaris V-8 engine, which it assembles in Cadillacs. In the mid-1990s the company was making 25,000 to 30,000 cars a year and needed magnesium for that alone. Demand from General Motors (GM), which produces more than 9m cars a year, and Toyota (TM), which produces almost as many as GM, is enough to keep the industry excited.
Before 1949, although China had abundant magnesium smelting resources, in the long years, due to the imperialist invasion and the rule of the Kuomintang, China's magnesium production was almost in a blank state. In July 1938, Japan established Manchuria Magnesium Industry Corporation in northeast China. In October 1943, it built a magnesium factory in Yingkou with electrolytic production and design capacity of 800/a and put into operation. By August 1945, only 691t magnesium was produced. Because some production technical problems have not been well solved, the production capacity has not been reached.
In 1943, a pilot plant with an annual output of 300t was built in Fushun Aluminum Plant by using the thermal reduction method of calcium carbide to reduce magnesium oxide, and a small amount of magnesium was trial-produced. The above factories were seriously damaged before liberation in 1949, and the equipment and technical data were lost.
In February 1954, the state approved the construction of magnesium workshop in Fushun Aluminum Works. The construction began in April,1957, and the first batch of magnesium ingot of new China was produced on December 30,1957. The production of the workshop has made a great contribution to the development of China's magnesium industry.
From 1958 to the 1960s, China has done a lot of work in the development of magnesium industry, has prepared for the preparation of Yingkou magnesium factory, Yancheng magnesium factory, qingxi magnesium factory, but due to a variety of reasons have stopped. Until the beginning of 1966, a 60/ A Pijiang process magnesium workshop was built in Lanzhou 205 Plant, which was the first silicon thermal process magnesium workshop for industrial production of metallic magnesium in China. It calcined dolomite with a vertical furnace with an inner diameter of 1.8m, and there was a horizontal tank reduction furnace composed of 40 reduction tanks. Gas is used as fuel for reduction and refining.
From the end of 1960s to the end of 1970s, the company had carried out magnesium smelting test and production of horizontal reduction furnace by internal thermal silicon method in Fushun, Zhengzhou, Lanzhou, Minhe and other manufacturers, and made some progress, but stopped production one after another because of high consumption of graphite electrode plate and tank.
Since 1970, 17 local small magnesium plants (workshops) with seawater brine and dolomite as raw materials have been developed rapidly in 10 coastal provinces and cities, among which 12 adopt electrolysis method. These small magnesium plants from small to large, from soil to foreign, side test, side production side construction, gradually complete the supporting system, to 1976 symbiosis output 1242T metal magnesium, solve the urgent need for magnesium in China. In the four years from 1975 to 1978, only 662 tons of magnesium was imported, 15.5 percent of the amount imported in 1974 and 9.9 percent of 1973. Later, these small magnesium plants due to the process and method of clearance, the production scale is small, especially tons of magnesium electrolytic power consumption as high as 55,000 kW. Production is in a productive thanks to the situation of less production and less loss, coupled with the local power shortage, does not guarantee the normal power supply, have stopped production.
Since the 1990s, with the deepening of reform and opening up and the deepening of market economy, magnesium industry and other industries have also developed by leaps and bounds. In 1995~1996, pijiang magnesium plant almost spread all over the country, and there were more than 40 jointly built. By the end of 2000, according to statistics, more than 120 production enterprises have a production capacity of more than 300,000 tons, output of nearly 200,000 tons, exports of 165,000 tons, output of more than 1/3 of the world's total output, exports of more than 1/3 of the world's consumption, has become the world's largest producer of raw magnesium and the largest magnesium products export. In 2002, China produced 268,000 tons of magnesium and exported 209,000 tons.
