Cadmium Ingot

Introduction 

Cadmium and zinc are found in nature together.It is a good neutron-absorbing metal, made into rods that slow the rate of chain fission reactions in nuclear reactors, and Cadmium compounds useful in zn-cadmium batteries.Rare elements, symbol Cd.It's silver white.Melting point is 321 ℃.The ratio of material to cadmium in the crust is 1000000:0.1 ~ 1000000:0.5.Cadmium Ingot is extracted from zinc ore or sulphur-cadmium ore as a by-product and is mostly used to protect other metals from corrosion and rust, such as electroplated steel, iron products, copper, brass and other alloys.Another use is to make a bright yellow pigment called cadmium-yellow, which can be used in advanced paints and paints.

use

Used in the manufacture of alloys: as an alloy group, cadmium can be mixed into many alloys, such as hard copper alloys containing 0.5% ~ 1.0% cadmium, which have high tensile strength and wear resistance.Cadmium (98.65%) nickel (1.35%) alloys are used as bearing materials for aircraft engines.Cadmium is found in many low melting point alloys, with the famous wood fusible alloy containing 12.5% cadmium.

Cadmium rods has a large thermal neutron capture cross section so alloys containing silver (80%) indium (15%) cadmium (5%) can be used as control rods for atomic reactors.

Cadmium compounds have been widely used in the manufacture of (yellow) pigments, plastic stabilizers, phosphors, insecticides, fungicides, and paints.

Used for electroplating, etc.Cadmium oxidation potential is high, so it can be used as a protective film of iron, steel, copper, widely used in electroplating anticorrosion, but because of its toxicity, this use has a reducing trend.

Rechargeable batteries: nickel-cadmium, silver-cadmium, lithium-cadmium batteries have the advantages of small size and large capacity

Cadmium is used in the manufacture of electrical alloy, such as most of the electrical contact of the electric switch USES the silver cadmium oxide material, has good conductivity, small arc, good welding performance advantages, such as resistance [4], widely used in household electric appliance switches, automotive relays, etc. [5], but as toxic cadmium and by the European Union "discarded electrical and electronic equipment directive (WEEE) and on the limit the use of certain hazardous substances in electrical and electronic equipment directive of two directive (RoHS) , the influence of the silver cadmium oxide gradually in the electric switch is environmental protection material, such as silver tin oxide, silver nickel material replaced.

History

In 1817, Stromell, Germany, separated the brown powder from the impure zinc oxide and heated it with charcoal to produce cadmium.

Cadmium Ingot was professor of chemistry and medicine at the university of gottingen in Germany who first discovered cadmium.He is also a government-appointed inspector of pharmaceutical manufacturers.It was during his visit to the drugmaker that he noticed problems with zinc-containing drugs that led to his discovery of cadmium in 1817.Because the new metal was found in zinc, it was named Cadmium after Calamine, the zinc ore. The element symbol was Cd.

Cadmium was discovered much later than its Cousins, mercury and zinc.Cadmium compounds is more abundant in the earth's crust than mercury, but once it appeared, it attracted people's attention with its strong metallic luster, high specific gravity, special fluidity and ability to dissolve a variety of metals.The content of cadmium in the earth's crust is much less than that of zinc.The metal cadmium is more volatile than zinc, so it escapes earlier than zinc at high temperatures, escaping detection.This means that cadmium is unlikely to have been discovered before zinc.

Distribution of reserves

In nature, mainly sulfur cadmium ore exists;A small amount also exists in zinc ore, so it is a byproduct of zinc smelting.The main mineral of cadmium is sulfur cadmium ore (CdS), which is stored in zinc ore, lead-zinc ore and copper lead-zinc ore.The world's reserves of cadmium are estimated at 9 million tons.

Asia is the world's largest producer of primary cadmium, mainly in China, South Korea and Japan.

In 2011, due to the impact of the earthquake in northeast Japan, several major cadmium production bases in Japan were temporarily closed. In 2012, the gradual resumption of related Japanese enterprises promoted the growth of global cadmium production, which was estimated to be 23,000 tons in 2012.

According to global mineral statistics released by the U.S. geological survey in January 2013, China produced 7,000 tons of cadmium in 2012, accounting for 30.43% of the global total.North Korea produced 4,100 tons of cadmium in 2012, accounting for 17.83 percent of the world's total.