Rhodium Applications and Rhodium Investments
Rhodium is a hard silvery white and durable metal that has a high reflectance. If slowly cooled from a red hot state it changes in air to the sesquioxide, which at higher temperatures converts back to the metal. Rhodium has both a higher melting point and lower density than platinum. It is not attacked by acids and only dissolves in aqua regia. Consider investing in Rhodium and companies involved in Rhodium.
The primary use of this element is as an alloying agent for hardening platinum and palladium. These alloys are used in furnace windings, bushings for glass fiber production, thermocouple elements, electrodes for aircraft spark plugs, and laboratory crucibles. Other uses include:
- It is used as an electrical contact material due to its low electrical resistance, low and stable contact resistance, and its high corrosion resistance.
- Plated rhodium, made by electroplating or evaporation, is extremely hard and is used for optical instruments.
- This metal finds use in jewelry and for decorations. Often it is used to give white gold extra shine.
- It is also a highly useful catalyst in a number of industrial processes (notably it is used in the catalytic system of automobile catalytic converters and for catalytic carbonylation of methanol to produce acetic acid by the Monsanto process). It is used to catalyse addition of hydrosilanes to a double bond, a process important in manufacture of certain silicone rubbers.
- The complex of a rhodium ion with BINAP gives a widely used chiral catalyst for chiral synthesis, as in the synthesis of menthol.
The industrial extraction of rhodium is complex as the metal occurs in ores mixed with other metals such as palladium, silver, platinum, and gold. It is found in platinum ores and obtained free as a white inert metal which it is very difficult to fuse. Principal sources of this element are located in South Africa, in river sands of the Ural Mountains, in North and South America and also in the copper-nickel sulfide mining area of the Sudbury, Ontario region. Although the quantity at Sudbury is very small, the large amount of nickel ore processed makes rhodium recovery cost effective. Main exporter of rhodium is South Africa (>80%) followed by Russia. However, the annual world production of this element is only about 20 tons and there are very few rhodium minerals. Moreover, it is generally difficult to determine if a rock sample does or does not contain platinum group elements. As of 2006, rhodium cost approximately six times as much as gold, by weight.
It is also possible to extract Rhodium from spent nuclear fuel, which contains an average of 400 g of Rhodium per metric ton. Rhodium produced in such a way contains radioactive isotopes with half-lives of up to 2.9 years and is therefore stored at least 20 years in a secured area to allow it to become stable. Every 2.9 years of isolation reduces the radioactivity by 50%. Fission Rhodium has a specific activity of 8.1 curies of radioactivity per gram after 5 years isolation. Under health physics safety rules any isotope that emits more than 1 ci of activity is a hazard however after 8 years the activity falls to 4.1 ci, after 11 years it is 2.2, after 14 years 1.1, after 17 years .55 ci ans after 20 years only .27 ci. After 30 years the activity falls to 2.702E-4 ci, which is under the threshold for low level risk by even the most stringent health physics rules. The radioactivity of Rhodium falls off so quickly because the percentage or Rh-102 in the recovered Rhodium is only a trace amount and the remainder of the material absorbs the energy released. Rhodium averaged $26.43 per gram or $1000 per troy ounce over the last 30 years and $6200 per troy ounce in May 2006, adding significantly to the resource value of reprocessed fission waste.
Remember to do your research, compare companies and invest wisely, consider looking into Rhodium as your next investment.