Platinum group metals are six noble metallic elements that are found in the d-block of the periodic table. They are also called transition metals. These metals are rare and precious. Their production impacts the environment.
Osmium
Osmium is a platinum group metal, occurring in nickel-bearing ores and river sands in South America, North America, and Ontario. It is also used as a catalyst in industrial processes.
In addition to being one of the hardest platinum metals, osmium is the densest known naturally occurring substance. This property makes osmium ideal for use in devices that are able to restrict wear from friction.
Although osmium is not widely used, it has several important applications. It is used in a variety of metallurgical processes, including fuel cells. Also, it is an effective catalytic agent in organic reactions.
The most common oxidation states of osmium are a +4 state and a +3 state. It is a very hard metal that is difficult to fabricate. It has the highest melting point of the platinum group metals.
Palladium
Palladium is an important component in catalytic converters. The catalysts are used in the automotive industry to convert pollutants in exhaust systems into non-toxic and less harmful substances.
These converters are used in vehicles to control the emissions of carbon monoxide, nitrogen oxides, and sulfur dioxide. They also help the vehicle’s engine to operate more efficiently.
As part of the platinum group, palladium is one of the hardest and least dense metals. It has a melting point of about four and a half times that of lead. This property makes palladium an excellent oxidation catalyst.
Palladium is used in numerous manufacturing processes, and is especially beneficial in chemical processes that require hydrogen exchange. One of the most common applications of palladium is in the manufacture of fuel cells. In addition, palladium is useful in the production of dental alloys, crowns, and jewelry.
Rhodium
Rhodium is a platinum group metal (PGM) and was discovered by English chemist William Hyde Wollaston in 1803. It is a silver-white, hard, metallic element that is also resistant to tarnishing and corrosion. This makes it an ideal choice for use in catalytic converters.
Aside from its unique ability to reduce nitrogen oxide in the exhaust gas of gasoline engines, rhodium is widely used in headlight reflectors, as a catalyst in chemical reactions, and as a coating for optic fibers. In addition, rhodium is also a popular alloying agent for platinum.
Because of its high melting point, rhodium is an excellent choice for use in glass. The rhodium-platinum alloy is also widely used for catalysts in extremely hot chemical environments, including those involving nitric acid.
However, the demand for rhodium is relatively small. In 2010, the US Geological Survey reported that rhodium had a global demand of 77 percent. Despite this, there is only a limited supply. Therefore, prices are likely to remain high for the foreseeable future.
Ruthenium
Ruthenium is a metal that is used for electrical contacts and alloys. It is one of the platinum group metals. Ru is a hard, white, shiny metal. Unlike its cousin, rhodium, ruthenium is a polyvalent metal that is not reactive with most chemicals. In some applications, it acts as a catalyst.
Ru is usually found in North America and South America. In some instances, it is associated with osmium. A large global reserve of ruthenium is estimated to be around 5,000 tonnes.
Ruthenium is an important element for science and technology. It is used as a catalyst in industrial processes and in some applications it acts as a plating material for electric contacts. Several applications use ruthenium in order to improve the durability of a specific product. Among these are chip resistors and wear-resistant electrical contacts. Moreover, ruthenium is also used in dye sensitized solar cells.
Impacts of pgm production on the environment
Platinum group metals (PGMs) are used in a variety of industrial applications, including nitric acid manufacturing, aircraft turbines, and automotive catalytic converters. These metals have excellent catalytic properties, which enable chemical processes to accelerate.
They also exhibit good electrical properties. PGMs are largely recycled, which reduces their environmental impact with every round. A study by the International Platinum Group Metals Association (IPA) examined the environmental effects of producing these materials.
The study covers a range of categories: primary production, mining, recycling, secondary production, power consumption, and process emissions. Data was compiled from 11 IPA members representing all parts of the pgm production chain.
Mining accounts for 69% of the global production of pgms. Although this is a relatively energy-intensive process, it results in significant amounts of valuable minerals.