Year: 1860

| 1t is we'll known that BY the ordInsry process
OF quartz crushing, considerable per centags
OF the gold contained in the rock IL lost. This
is proven by repeated assays which have been
made Of quartz tailings, after being subjected
to the usual process Of separating and amalga-
mating the gold. The most Of the gold lost 10
contained in the suIphurets, and the per cent
age of loss varies accord Ing as the sulphurets
are more or less decomposed. The amount Of
gold contained in the taiiings is not sufficient
to pay the expense Of assaying them Ia balk;
but the sulphurets, when separated from the
mass of tailings, can be assayed with profit.
The snlphurets are usually worth from $50 to
500 ten, and large quantities have been
bought up in this State and shipped to France,
where they have process for separating the
gold unknown here.


The paying quartz leads which have been
worked in Nevada county, probably contain,
on an average, two and half per cent. Of sui
phurets; and II will readily be inferred that
process by which these oan be separated, while
the rock is being crushed, without additional
expense, is worthy the attention of practical
quartz miners. This result IL now effected by
machine known as Bradford's Patent Ore
Separator, which was invented, we believe, for
working copper mines, bus which seems to be
precisely adapted to separating sulphurets from
quartz taillngs and at the same time amalga-
mates whatever free gold may have escaped.
The patent for California is owned by Messrs.
= - nj
months ago, they put up eight Of these ma
chimes at the Empire Quartz Mill, in Grass
Valley, and worked over large quantity Of
tailngs which had accumulated at that mill
They were at the additional expense Of hand
ling over all the tailings, but we learn that
enough free geld was saved to pay the expense
of running the machines, aud the sulphuress
were afterwards sold and shipped to France.
The machines have lately been removed to Ne
vada, and are now In operation at the mill Of
the Nevada Quartz Mining Company, on Amer
ican Hill. The mode Of working is as follows
The tsilings, after being subjected to the usual
process of extracting the gold, are received in
Patent Rotary Crushsr, capable of pulveri-
zng all the rock crushed in any ordinary mill,
as fast as 1t comes from the battery. They
then pass into the Ore Separator, and are re-
ceived on vibrating table, which separates the
sulphurets from the sand on the principle Of
specific gravity, and the free gold Is either
amalgamated on the table, (Which 10 galvan-
ized,) or thrown over with the sulphurets. The
separation is effected in much the same manner
as gold and sand are separated by hand when
placed on O blower. The vibrating table in
this machine has the eame motion as is given by
hand to the blower; the heavy sulphurets are
carried forward and fall into box, while the
sand, or light quartz, which contains little or
no gold, and which constitute the bulk of the
tailngs, are carried off in another direction.


With the eight machines which 4essrs. Ferre
Il Co. now have in operation 1t the Nevada
Compauy's mill, they are enabled TO run
through some twenty-five or thirty tons Of tail.
ings day. Four Of them are used iu working
over the old tailings. and the other four are
used ia separating the sulphurets as fast as the
rock Is crushed In the mill.


Having been engaged in quartz mining as



the business since, we have anxlously watched
the improvements in machinery that have from |
time TO time been brought before the public;
aud from personal examination OF the work.
ing of Bradford's Ore Separator. we are satis-
fed II is the best aud most economical machine
which has yet been introduced for saving the
gold contained in the quartz. By attaching
the machines to mill, so as TO receive the tail.
ings after going through the ordinary process
Of amalgamation, they can be worked without
extra expense; II any free gold has escaped it
will be amalgamated on the tables, and at the
same time the sulphurets and rusty gold are
separated from the mass of tailings


Nevada county Was among the first TO en-
gage in the quartz business, and has steadily
kept in advance Of the other counties, both In
the quantity Of rock crushed and in improve
ments in machinery. Any ono who has the
least practical knowledge Of quartz mining will
readily imagine the great impetus that would
be given to the business by the introduction of
machinery that would save two or three dollars
more than Is now saved on every ton Of rock
crushed. Leads that are now barely paying
expenses would then net their proprietOrs
handsome income, and hundreds of others, now
regarded as almost worthless, and are not work
ed for the reason that they lack ono or two
dollars ton Of paying, would then be devel-
oped. Quartz mining, We believe, is destined
to become the principal business of this State.
But the business is yet in It's infancy, aud when
we reflect on what has been accomplished in the
past few years. we are prepared to look for still
further improvements, both in cheapening the
process Of crushing the rock aud in savin &
more Of the gold.


| THE London Times seems to think Prussia 10
preparing for war; Her standing army consists