Mr. H. J. Saunders, legal manager of Fraser's G.M. Company, has handed us
the following "preliminary report on retort-cake, &c., received on
December 23, 1889," by Mr. B. H. Woodward, F.G.S., from the Company for
analysis.
The Directors hope to have Mr Woodward's full report early next week.
TO THE DIRECTORS OF FRASER'S G. M. COMPANY.
The retort cake was dark brown and black and purple. Only the crust was
gold colour, and even that was highly magnetic, like the darker parts.
The smaller cake had the appearance of black lava. It is quite infusible
before the blow-pipe, even in minute splinters. It contains about 13 1/2
per cent. gold, the remainder consisting largely of iron with some
silver, copper, mercury, and other metals and sulphides. It cannot be
worked in the usual way, for retort gold as a rule contains 98 to 98 1/2
per cent gold. It will not run down reflexes like metallic callers,
unless a very large amount is used, 10 or 12 times its bulk, consequently
I have roasted all to drive off the sulphur and volatile metals and am now
treating it with acid to dissolve out the iron. This is a long process,
for even after five days in strong acid all the soluble portions are not
yet out. Even then it can only be run down in small quantities (about 1/4
lb. into a pot that would take 12 lbs. gold) as it effervesces so much.
The amalgam was in part bright but considerable portion was rust coloured,
and it will require the same treatment as the retorted portion. I am
making analyses of the minerals in the quartz. The water contains
aluminium, sodium sulphate, magnesium sulphate, sodium chloride, and
calcium sulphate.
The salts acting on some of the minerals may have caused the mercury to
amalgamate in so extraordinary a manner with the iron, but until the
researches are complete I cannot say positively.
(Signed) BERNARD H. WOODWARD, F.G.S.
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