226 TRANSACTIONS OF THE 
METALLURGY OF THE CHLORIDE VOLATIL- 
IZATION PROCESS. 
BY C. C. STEVENSON.2 = 
GENERAL STATEMENT. 
The chloride volatilization process is a metallurgical 
method, which experiments have indicated to be especi- 
ally well adapted to the treatment of low-grade, oxidized 
and semi-oxidized complex ores—those classes of ores 
which are difficultly treated with methods employed in 
our present practice. Furthermore, there are vast quan- 
tities of such ores, as are found in our western regions, 
that are lying idle for want of a suitable metallurgical 
treatment and which are most probably amenable to the 
volatilization process. 
HISTORICAL BRIEFS. 
Chloridizing roasting of metalliferous ores has long 
been in practice. In 1854 M. Becquerel, of Paris, roasted 
argentiferous galena with salt and extracted the silver 
chloride thus formed with a brine solution. Owing to 
the lack of a suitable means of recovering the silver from 
the salt solution, the scheme at that time had no economic 
value. Later investigations, however, resulted in effect- 
ing improvements that have made chloridizing roasting 
an important metallurgical process. 
The main disadvantage that accompanied the chlor- 
idizing roast preparatory to leaching was the loss of 
metals due to volatilization. The losses sustained during 
the roast are usually high, in some cases 30 per cent of 
the metal values have been dissipated and lost, depending 
primarily on the temperature of the roast. 
1Assistant Metallurgist, Department of Metallurgical Research, 
University of Utah. 
