Rhenium is the 75th element in the periodic table. The chemical symbol Re (lat. Rhenium) is a silvery-white metal, similar in properties to tungsten and molybdenum. There are two isotopes of rhenium: 185Re and 187Re. Heavy isotope is almost twice as much and he, unlike light, radioactive. Emitting β-rays, Rhenium-187 for a billion years turns into osmium. Rhenium-185 isolated in pure form in 1925 by German chemists spouses Nodak. It was the last open non-radioactive element.
This rare earth element found in molybdenum and copper ores. Very rich deposits in Chile, USA and Russia. If the annual level of consumption of rhenium 40−50 tons, humanity enough world reserves of 250−300 years, without regard to the secondary use of this metal. Depending on the purity, the price of 1 kg of rhenium can vary from 1000 to 10,000 dollars.
|The atomic number of Re||Atomic (molar) mass, g/mol||The degree of oxidation||Density [g/cm3]||The melting temperature t°C||The boiling point of t°C||The heat of fusion kJ/kg|
|No. 75||186,2||-1, 0, 2, 3, 4, 5, 6, 7||21||3186°C||5596°C||34|
For decades, the need for Rennie remained stable. The main consumer was the electrical industry. Basically, the rhenium was used for making thermocouples and filaments of vacuum devices. The need for Reni began to grow in the second half of the last century when the petrochemical industry began using the rhenium-platinum catalysts. Such catalysts has allowed the production of cheaper high-octane gasoline. Compared to the old platinum-rhenium catalysts was 50% more efficient and has served 4 times longer. If previously significant part of the rhenium went to the alloying heat-resistant alloys, with the last quarter of the twentieth century 75% of the rhenium was used for the production of catalysts. Today, this metal is important not only in the metal and electrical sectors, but also in the petrochemical industry.
It is refractory and heavy metal with properties similar to molybdenum and tungsten. The melting point (3170°C) rhenium is second only to tungsten. One cubic centimeter of rhenium weighs 21 grams, heavier — only osmium, iridium and platinum. Pure rhenium is much ductility of tungsten. It is possible to roll and pull into a fine wire under normal conditions. Was discovered and «rhenium effect»: it appears that this metal increases both the strength and ductility of molybdenum and tungsten. Due to the high modulus of elasticity, the hardness of rhenium after treatment increases significantly due to shot peening. To restore the plasticity, it is annealed in hydrogen, vacuum or inert gas. Up to 1200 °C the hardness is higher than that of tungsten, and is much higher than the strength of molybdenum. Rhenium can withstand repeated cooling and heating without loss of strength. The resistor he’s four times higher than tungsten and molybdenum.
Rhenium is more resistant to oxidation than tungsten, with age does not tarnish in air, while maintaining pristine lustre, almost insoluble in hydrochloric and hydrofluoric acids, but reacts weakly with H2 SO4, even when heated, but easily soluble in nitric acid and in solution of H2 O2 forms rhenium acid. With mercury rhenium forms an amalgam.
It is extracted from molybdenum and copper sulfide ore with scanty salt content of rhenium using pyrometallurgical methods (converting, melting, oxidizing roasting). Upon firing, the oxide of rhenium sublimates and then is captured by special filters. Part of the rhenium is usually preserved in the roasted product, where goes in soda or ammonia solution, from which later the metal reduced by hydrogen. Smelting of copper concentrates with smoke usually carried away 50−60% of Re. In the processing of copper concentrates sulfuric wash acid becomes the main source of this metal.
The use of rhenium is determined by high electrical resistance and heat resistance, resistance to aggressive chemical factors, high catalytic activity (close to platinoids). Modern nuclear power can’t do without alloys containing rhenium. At the dawn of the atomic era began to use a tungsten alloy with 26% rhenium for shells of fuel elements and other components operating in the reactor at t° 1600−3000°C. the strong position rhenium and its alloys is in aircraft and space technology. In particular, an alloy of tantalum with 2.5% of rhenium and 8% tungsten is indispensable for the heat shields of the modules returning from space to Earth. High physical and chemical advantages (plus good weldability) determine the interest in rhenium big industries who shoulder large expenses. 2/3 of rhenium goes to the alloying heat-resistant steels and coating other metals. Pure rhenium is one of the most critical parts. Domestic alloys based on tungsten containing 5, 20, to 27% Re (BP-5, BP-20, BP-27ВП), based on molybdenum — 8, 20 to 47% of rhenium. Also used tungsten-molybdenum-rhenium alloys — forging, high-tech, easily welded. They work in the most difficult conditions: withstand high temperature, shock, vibration, contact with aggressive substances.
Supply certified products of alloys of rhenium. The specification included data on the percentage composition and mechanical properties of products. We can easily buy in bulk any semi-finished products for large-scale production. We also work with retail buyers. A high level of service and speed of service are the face of our company.
Buy at best price
On the website LLC «Electrocentury-steel» reflects the most current information on the acquisition of rental of rare and refractory metals today. Our best managers are ready to provide qualified advice on any current issues. Sell semi-finished products of rare and non-ferrous at a competitive price. The products are manufactured on the most modern equipment and meets the quality requirements of Russian state standard and international quality standards. Regular customers receive a discount system of discounts.