What are the different uses for cadmium?

Cadmium is a very toxic heavy metal, and most of its compounds are also toxic substances. Cadmium has a wide range of uses. Cadmium salts, cadmium steam lamps, pigments, smoke bombs, alloys, electroplating, welding flux, standard batteries, metallurgical deoxidizers, atomic reactors, etc., all use cadmium.

Cadmium metal application and distribution

The main application of cadmium is in the battery industry, where it is used in nickel-cadmium batteries, but nickel-cadmium batteries in laptops and mobile phones have been gradually replaced by lithium-ion batteries. The toxicity of cadmium has led to legislation banning it, particularly in the European Union. Currently, nearly 86% of the world's cadmium is used to make nickel-cadmium batteries, 9% to make pigments, 4% to make paints, and 1% to make alloys, solar panels and stabilizers.

In terms of consumption: By country, China, Belgium and Japan account for 77% of the global cadmium consumption, followed by China (33%), Belgium (32%) and Japan (12%). In terms of downstream application markets, cadmium-nickel batteries, which account for the majority of global consumption, are remainder distributed as follows, in decreasing order of consumption: pigments, coatings and plating, plastics, non-ferrous alloys, and other specialized uses (including photovoltaic equipment).

Nickel cadmium battery

Small portable nickel-cadmium batteries account for 80% of cadmium consumption in nickel-cadmium batteries, which are mainly used in consumer electronics. The remaining 20% is made up of industrial nickel-cadmium batteries, which are mainly used in the aviation and rail industries. In aviation applications, nickel-cadmium batteries can provide starting power for engines and can be used as backup power for aircraft circuits. In railway systems, nickel-cadmium batteries are used to start locomotive engines and provide power for passenger cars and track lights.

Nickel-cadmium batteries are very popular in mid-range consumer electronics and appliances because of their cost advantages over other chemical batteries. The average price of nickel-cadmium batteries in 2012 was around $1.20, nearly 62% cheaper than lithium-ion batteries and 77% cheaper than nickel-metal cyanide batteries.

Over the past few years, lithium-ion batteries have begun to replace nickel-cadmium batteries in some low-end electronics as their cost has fallen and their storage capacity has increased.

Compared with other rechargeable batteries, nickel-cadmium batteries have superior stability and reliability in technology, so nickel-cadmium batteries still maintain their status in some industrial applications.

Nickel-cadmium batteries power electric cars and are also used in many hybrid cars. Nickel-cadmium batteries are also being used as buffer storage for electric hybrid power systems in remote and underdeveloped areas. The hybrid system is transportable and renewable.

Industrial-scale nickel-cadmium batteries also have the potential to store energy for grid-connected solar or wind power installations. Storing excess power during periods when demand is low and being able to dispatch it for use during peak periods. The stability and reliability of nickel-cadmium batteries also allows them to be used offshore in harsh environments.

Nickel-cadmium batteries advantages and disadvantages

Advantages

Long service life;

Battery self-discharge is small;

Wide range of temperature;

Overcharge and overdischarge resistance, stable discharge voltage;

Good mechanical performance;

Disadvantages

Low utilization rate of active substances;

High cost;

Negative cadmium is toxic;

Memory effect when battery has long shallow charging and discharging cycle;

The nickel-cadmium battery industry is almost entirely concentrated in Asia, with key producers including: BYD Co., LTD. (China); Panasonic (Japan); Sanyo Electric (Japan).

Cadmium sulfide pigment features and uses

Inorganic golden yellow cadmium sulfide is mainly used as a pigment. In pigment applications, cadmium pigments are replacements for zinc and mercury, and cadmium sulfides, from golden yellow to purple, are replacements for selenium. 

Cadmium pigment has the characteristics of light fastness, light fastness, excellent weather resistance, high temperature resistance, strong hiding power, strong tinting strength, no migration, no color bleeding, etc. It is widely used in plastics, coatings, masterbatches, rubber, leather, gravure printing inks , art pigments, high-grade paint, enamel, ceramics, glass, colored sand and other building materials and electronic industries. 

In terms of polymer coloring, it can be used for almost all resins and plastics. But it is mainly used in the coloring of engineering plastics, because engineering plastics need to be processed at high temperature, and cadmium pigments can not mutate under the environment of constant temperature.

Cadmium coating and plating

The application of cadmium coatings in aviation and military fields plays an important role. Replacing coatings in these applications is likely to raise safety concerns. Cadmium is commonly used in the electroplating of firmware on aircraft landing gear, and because cadmium has properties not found in other anti-corrosion coatings, it is also used in the production of parachutes.