The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1900-01-11
NEWS AND GOSSIP o. THE MINING WORLD.

teen feet in diameter and eight feet deep.
AZ the liquor flows into the precipitation
tanks It y constantly stirred by one
forced Under ps ws ar and
the tank 4 filled. Zinc dust i used for
eeSson sss tree s1d as s s SU
the tank is frst fiiied thirty pounds Of
, ,hs i Is put In twenty pounds !: used on
third. and thereafter, TIL the ciean-up on
the end Of the month. fifteen pounds OF
nS 's &. or s charlie charge no so o
when one-quarter Of the total used Tor
Denf f adds srs s. 4 he put nR ns naoh 5
precipitation by zinc dust combined with
Is pssne BY s. Cart
LIE Ia Mar. and It gives excellent re-
1.-THE solution is allowed to settle for
ter process. which collects the suspend
ed particles There are ten stillwan-
S,srSs smitnvails itsr presses
distance frame pattern. from which the
LIQUOR nows In clear, pellucid stream to
s ana esht ee fee feet barr sam se
while the original precipitation solution
he fo o on nsr
OF gold precipttated is one and one-third
pounds. To maintain the solution at
easso so 4, Of k In 100 os Of
ton before standardizing with potassium
cyanide. This effects a saving Of cya-
nree any ~ nsdnrnsinS any aScidty II the
more vigorous action of the solution on
the zinc dust. II Is also found that this
increased aikaiinity Of solution increases
Gold From the Final solution.
"No definite figures are given out as to
the gold contents OF the battery charge
or the average value Of the mixed pro-
TSs ores q Mere In Hs an s
limits and 1t Is well known that the rich
est Of the district are the base ores of
f has,a De d a Mar mine 50 that the mill
base ores treated. At present the oxidized
and mixed product form the great bulk,
perhaps %han g, tnres,quartsrs Of the total. but
reversed; for BY far the greater tonnage
able al toasy The Is bb bass prob
tons. All told, las men are employed in
handed ana this force viii 'H be- r or Sse
reduced, increasing the tonnage per
monthly clesan-ups are made and
precipitating tanks and one-half in filter
presses. though the weight Of product
taken. from the precipitating tanls Is
thrsefoid that from the presses. The pro-
duct is carried to the refinery, dried in
shallow iron pans in mufle furnace
where the major part of the free zinc is
converted to oxide-pulverized through
M-inch screen and sampled. At that
stage It carries about 20 per cent. gold
the richest cleanup ran $65 per pound,
and the average is above SIS. When the
mill started this product was SO per
pound, and uniform Improvement has
been made; 1t may be noted that, In
variably. there Is one ounce of silver to
100 ounces Of gold in the product
Next the product is treated In dis
solving tank In solution Of sulphuric and
nitric acid which removes the remaining
free zinc. zinc oxide. arsenic and mer-
curry, and brings the product to 60 per
cent. gold. the other 40 per cent being
largely. silicious shines. This is filter
pressed. dried in muffie furnace, crush
ed roughly to 1e-inch or less mixed with
nux consisting OF one part potassium car
Donate, two parts sodium carbonate, two
parts borax glass. and melted in gra-
phfte crucibies In an oil-burning furnace
Resultant bullion is $50 fne."