Rhenium Sources in Modern Times

The reserves are estimated at 2400 tonnes, half of them in Chile. The reserve base (known ore bodies that may be worked at some future time) are quite large in the USA, 4500 tonnes, in Chile, 2500 tonnes and in the whole world 10000 tonnes. 

The total world rhenium production in mines is estimated [29.4] at 28 400 kg for the year 2000, although this figure is uncertain. A value of 12 600 kg is included for the USA, although the production figure is secret. It has been calculated from the official values for MoS production in the USA. The US consumption of rhenium in 2000 (from domestic sources and import) was 32 000 kg, a considerable quantity considering that a production goal of 1 g was reached only 71 years earHer. 

Rhenium with its highest oxidation number +7 corresponds to Re Oy. This oxide has a property that is important for the modern production of rhenium. It is very volatile, with a boiling point of 350°C. Molybdenum oxide MoOj has a boihng point of llSrc but starts to subhme at 750°C. During the roasting process with the maxi- 

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