Zinc is an important non-ferrous metal raw material. At present, zinc is second only to copper and aluminum in the consumption of non-ferrous metals. Zinc metal has good calendering, wear resistance and corrosion resistance, and can be made into physical and chemical with various metals. An alloy with better performance. The main products produced by the original zinc enterprises are: metal zinc, zinc-based alloys, and zinc oxide. These products are very versatile and have the following main aspects:
(1) Zinc plating
Used as anti-corrosion coating (such as galvanized sheet), widely used in automotive, construction, shipbuilding, light industry and other industries, accounting for 46% of zinc.
Zinc has excellent resistance to atmospheric corrosion, so zinc is mainly used for surface coating of steel and steel structural parts. After oxidation of the surface of the hot-dip galvannealed alloy for electroplating, a uniform and fine protective layer of basic zinc carbonate ZnCO3•3Zn(OH)2 oxide film is formed, and the protective layer of the oxide film also has the function of preventing mold growth. Due to the good resistance to atmospheric corrosion of zinc alloy sheets, Western countries have also begun to use it as a roof covering material in recent years. It can be used as a roofing sheet for up to 120-140 years and can be recycled. The service life of galvanized iron sheets for roofing materials is generally 5-10 years.
(2) used to manufacture zinc oxide
Widely used in rubber, paint, enamel, pharmaceutical, printing, fiber and other industries, accounting for about 11%.
Used in the manufacture of dry batteries, in the form of zinc cake, zinc plate, accounting for about 13%.
Zinc has suitable chemical properties. Zinc can interact with NH4CI to release H+ cations. The zinc-manganese dioxide battery utilizes the characteristic of zinc. The zinc alloy is used as the outer casing of the battery, which is not only the container of the battery electrolyte, but also participates in the reaction of the battery to form the anode of the battery. Its performance is also widely used in the pharmaceutical industry.
(3) Used for casting zinc alloy
Mainly for die-casting parts, used in automotive, light industry and other industries, accounting for about 15%.
Many zinc alloys have excellent processing properties, and the pass processing rate can reach 60%-80%. Excellent medium-pressure performance, deep drawing, self-lubricating, extended die life, soldering or electric resistance welding or arc welding (need to be used in helium), surface plating, painting treatment, Good machinability. Excellent superplastic properties under certain conditions.
In addition, zinc has good resistance to electromagnetic fields. The conductivity of zinc is 29% of standard electrical copper. In the case of radio frequency interference, zinc plate is a very effective shielding material. At the same time, because zinc is non-magnetic, it is suitable for the material of instrument parts and instrument housing and coins. At the same time, zinc itself and its collision with other metals will not cause sparks, which is suitable for underground explosion-proof equipment.
(4) manufacturing copper alloy materials (such as brass)
Used in the automotive and machinery industries, accounting for about 15%.
Zinc has suitable mechanical properties. The strength and hardness of zinc itself are not high. After adding alloying elements such as aluminum and copper, the strength and hardness are greatly improved, especially the appearance of zinc-copper-titanium alloy. The comprehensive mechanical properties are close to or reach aluminum alloy, brass, The level of gray cast iron is also greatly improved in creep resistance. Therefore, zinc copper titanium alloy has been widely used in the production of small hardware.