The Background Knowledge of Tin

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What is Tin?

Tin is a relatively rare form of non-ferrous metals and the average content in the Earth’s crust is just 0.0001~0.0002%. It is one of the first invented and used metals. The bronze (Tin-copper alloy) is the symbol of Tin. About more than 3,500 years BC, humans began making and using alloys of copper and tin — bronze.

Tin is a silvery white and slightly blue metal, its surface gloss is connected with the casting temperature. Due to the formation of oxide thin films, usually the surface of tin ingot appeared to be golden brown. The melting point of tin is low -232°C; its boiling point is very high -2270°C; its specific gravity is 7.3 when the temperature is 20°C. The ductility of tin is very good which can be made into 0.04mm tinfoil, but it cannot be drawn into filaments. The conductivity of tin is less than copper but better than lead. Tin is not influenced by the air at room temperature. The prolonged contact with humid air will make it generate a thin oxide film on its surface and prevent further internal oxidation. Compared with most other metals, tin has great resistance to erosion. It can form alloys with various metals.

Tin powder is widely used as organic chemical additives and organic synthesis reductant in metal plating, powder metallurgy structural parts, porous materials, friction materials, metal-ceramic, diamond grinding wheels, metal graphite brush, clutch brake repair, special paint, flares and fireworks, rubber, plastics, etc. Currently the annual demand of tin metal powder is over 500 tons and with the development of powder metallurgy industry, its usage is growing rapidly.

The Distribution of Tin

Tin resources are distributed in 32 countries around the world. They are mainly in the eastern part of Pacific Rim which has good tin ore-forming conditions. The major tin-producing countries are China, Malaysia, Indonesia, Brazil, Bolivia, Thailand, Peru and other developing countries as well as Russia, Australia and other countries.

According to the comprehensive analysis of the statistical data from various sources, the world’s tin resources reserves is about 9.6 million tons based on the tin content, and reserve base of tin is more than 12 million tons. It is mainly concentrated in China, Brazil, Malaysia, Indonesia, Bolivia and other countries. Among them, the percentage of China’s tin reserves is at the top in the world which accounts for about 36.5% of the world’s total reserves; while Brazil is 22.9% and Malaysia accounts for 12.5%.

The Production and Consumption of Tin in China

The refined tin output of the world’s tin producers is influenced greatly by the factors of world economic situation, market price, resources status, consumers’ taste and production costs. China is a tin-producing country as well as a big consumer and trading power of tin. According to incomplete statistics, China now has more than 140 tin-producing enterprises of various sizes. Since the 80’s, due to the big appearance of local small-scale tin mining units, tin concentrates production makes a growing momentum, with an average annual growth rate above 10%. The growth of tin concentrates production will further stimulate domestic production of refined tin and its output has maintained a high production, high rate of growth (annual growth rate up to 13.7%). Since 1993, china’s refined tin output exceeded 50,000 tons. The output broke through in 1994 and 1995 for two consecutive years to 60,000 tons instead of Malaysia, and became the first tin-producing nation in the world. Particularly in 2000, the refined tin output broke through 110,000 tons, creating the world’s tin production record.

In terms of the total consumption of tin, China’s tin consumption was just 1.2~1.4 million tons in the 80’s and most of which were exported. Since the middle of the 80’s, with the development of national economic construction, there is an increased consumption of tin in the machinery, electronics, light industry and food sectors. Since the 90’s, tin consumption has entered into a rapid growth and reached 43,000 tons in 1996. Since then, with the growth in exports, the consumption fell to less than 40,000 tons. As a result of the expanded production of tin, the consumption reached the historical maximum of 52,000 tons in 2001 and became the world’s second-largest tin consuming country. Although tin consumption growth rate is up to 30.3%, the balance supply contradiction still exists, judging from the domestic market balance. To ease the contradiction between supply and demand in China, they export a large number of refined tin products which accounts for more than 50% of refined tin production.