EXTRACTION OF RADIUM FROM THE OLARY ORES. 147 



They describe the methods adopted by them in treating 10 

 tons of residues derived from about 30 tons of pitchblende 

 ore containing 54*2 per cent, of U 3 8 . The treatment of 

 the ten tons occupied two years, and resulted in the 

 recovery of three grams of radium chloride in a state 

 approaching purity. No analyses are given in this paper 

 and only very scanty details as to the plant used. 



As these residues were derived from ore containing 270 

 milligrams of radium (calculated as bromide) per ton, and 

 as the Olary ore, even when concentrated, contains only 

 eight milligrams, it is obvious that any process to be com- 

 mercially successful when applied to these latter ores must 

 be comparatively simple in operation, and must allow of a 

 considerable tonnage being put through annually. It may 

 be noted that eight milligrams of bromide to the ton means 

 one part in 125 million or one part of elementary radium in 

 214 million parts of concentrates. 



As first observed by H. Y. L. Brown the amount of visible 

 carnotite in the ore is negligible from an economic point 

 of view, and for practical purposes the ore consists of a 

 mixture of ilmenite, magnetite, and rutile, with small 

 amounts of carnotite and a mineral stated by Crook and 

 Blake to be probably tcheffkinite. Table I gives : — 



(a) Analysis of the ore complex excluding the carnotite, 



taken from Crook and Blake's paper. 



(b) Analysis of the concentrates now being treated at 



Woolwich. 



(c) Analysis of a typical Austrian pitchblende. 1 



Table I. 



a b c 



Lime 0*25 0*55 2*55 



Lead oxide 0*4 0*16 1*9 



Ferric oxide 17*87 17*4 1*14 



1 Brearly, Analytical Chemistry of Uranium, p. 43. 



