You might try :
Foreign Trade Dept,
Yunnan Tin Corporation,
Geiju,
Yunnan,
China
Telex: 64505 YTC CN
My contacts were Guo Chang Huo - Engineer and Wang Shu-Kai Manager Jijie
Smelter. China seems to have both alluvial deposits which are deep
mined hydraulically or by dredge and also large reserves of hard rock tin
which is less pure and lower grade. I am not quite sure whether the
latter have been exploited as fully as was first thought in the days of
the high tin prices of the early 1980s. Yunnan were developing a whole
range of smelting and refining techniques in those days. Some were
similar to those already in existence, others were truly innovative.
They included: slag fuming , vacuum distillation, mechanised
crystallisation, immersion smelting (a la Sirosmelt) and a variant of
alkaline electrolysis which was capable of separating very high impurity
levels. They also offered a range of dressing methods but I am not sure
if these were substantially better than what was available outside China.
I think there is a paper in one of the Inst Mining & Metallurgy Conference
Proceedings during the mid 1980s, either a special China conference or one
of the Lead/Zinc/Tin series. This series is the best source on
modern aspects of tin processing. Also P.A. Wright, "Extractive
Metallurgy of Tin" which came out in two volumes - one about 1970, the
other about 1985. There is also possibly a Roskill Report on tin,
again late to mid 1980s which would be an in-depth survey of all aspects of
the metal.
Sorry I can't give you hard references but these are recollections from
about ten years ago.
Regards
Richard
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