5 great uses for lead and zinc
Lead and zinc are widely used in electrical industry, machinery industry, military industry, metallurgical industry, chemical industry, light industry and pharmaceutical industry. In addition, lead metal also has many uses in the nuclear industry, petroleum industry and other sectors. More than 80% of the world's lead is used to produce lead-acid batteries.
Zinc is an important non-ferrous metal raw material. Zinc is second only to copper and aluminum in the consumption of non-ferrous metals. Zinc metal has good rolling properties, wear resistance and corrosion resistance, and can be made with a variety of metals with better physical and chemical properties. Excellent alloy. The main products produced by primary zinc companies are: metallic zinc, zinc-based alloys, and zinc oxide. These products are widely used and mainly include the following aspects:
1. Galvanized. Used as anti-corrosion coatings (such as galvanized sheets), it is widely used in automobiles, construction, ships, light industry and other industries, accounting for approximately 46% of zinc usage.
Zinc has excellent resistance to atmospheric corrosion, so zinc is mainly used for surface coating of steel and steel structural parts. After the surface of the hot-dip galvanized alloy for electroplating is oxidized, a uniform and fine protective layer of basic zinc carbonate ZnCO3o3Zn(OH)2 oxide film will be formed. This oxide film protective layer can also prevent the growth of mold. Because zinc alloy sheets have good resistance to atmospheric corrosion, Western countries have also begun to try to use them directly as roof covering materials. The service life of using them as roof sheets can be as long as 120-140 years, and they can be recycled and reused. However, using galvanized iron The service life of panels as roofing materials is generally 5-10 years.
2. Manufacturing copper alloy materials (such as brass). It is used in the automobile manufacturing and machinery industries, accounting for about 15% of zinc usage.
Zinc has suitable mechanical properties. The strength and hardness of zinc itself are not high. After adding aluminum, copper and other alloying elements, its strength and hardness are greatly improved. Especially with the emergence of zinc-copper-titanium alloy, its comprehensive mechanical properties have approached or reached the level of aluminum alloy, brass, The creep resistance of gray cast iron has also been greatly improved. Therefore, zinc-copper-titanium alloy has been widely used in the production of hardware.
3. Used for casting zinc alloy. Mainly die castings, used in automobiles, light industry and other industries, accounting for about 15% of zinc usage.
Many zinc alloys have excellent processing properties, and the pass processing rate can reach 60%-80%. It has excellent medium pressure performance, can be deep drawn, and has self-lubricating properties, which extends the life of the mold. It can be welded by brazing, resistance welding, or arc welding (need to be in helium), and the surface can be electroplated and painted. It has good cutting performance and has superior superplastic properties under certain conditions.
In addition, zinc has good resistance to electromagnetic fields. The conductivity of zinc is 29% that 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 as a material for instrument parts, instrument casings and coins. In addition, zinc will not produce sparks by itself or when it collides with other metals, making it suitable for underground explosion-proof equipment.
4. Used to make zinc oxide. It is widely used in rubber, paint, enamel, medicine, printing, fiber and other industries, accounting for about 11% of zinc usage.
5. Used in the manufacture of dry batteries, in the form of zinc cakes and zinc plates, accounting for about 13% of zinc usage.
Zinc has suitable chemical properties. Zinc can react with NH4CI to release H+ positive ions. Zinc-manganese dioxide batteries take advantage of this characteristic of zinc. Zinc alloy is used as the battery shell, which is not only a container for the battery electrolyte, but also participates in the battery reaction to form the anode of the battery. In addition, this property is also widely used in the pharmaceutical industry.
World lead consumption is mainly concentrated in the fields of lead-acid batteries, chemicals, lead plates and pipes, solders and metallurgy. Among them, lead-acid batteries are the most important field of lead consumption. In 2009, lead-acid battery consumption in the United States, Japan and China The proportions of lead reached 86%, 86% and 81.4% respectively. Based on environmental protection requirements, lead consumption in other fields is relatively low.
