The Butte daily miner. [volume] (Butte, Mont.) 1885-18??, 1886-01-01

ing interposed between the two breakers to
remove such ore AZ il already sufficiently
fine for the first set Of rolls, to which ali the
ore from the breakers In elevated, and
which are usually set to yield product not
larger than 4-inch. After passing one or two
sets Of rolls, the ore lie delivered to from.
mel-syste,n, having n mesh OF y and 1.24
inch for the two extremes, and being four, or.
better. five in number. Each size Of ore
goes to q separate automatic jig or pair 81
j igs, which are in most cases ARRANGED to
work through bed OF mineral Of the next
larger size, only the coarser sizes have q
side discharge. The jigs have from three to
four sleeves, and are all, believe, side
piston hydraulic jigs. A modification ii
the old Clausthal discharge is used to re-
move the concentrates in most cases,
though the cap and tube has also some
advocates.
The product Of the first sieve should be
always clean enough for smelling, while
that OF the second and third sleeves 10 either
recrushed or fed back into the machine.
The pulp which passes through the finest
sieve, 1.24 inch. is either carried to
the slime pits or fed direct to Frue van
ners or tables; or, as in the PARROT mill,
separated into equal-falling sizes by pointed
boxes, and the product OF each separator
by far the most perfect method.
The shines which flow over the pointed
boxes are caught in sumps or labyrinths,
and either thrown away or used as they
are. Being very silicious, AMI yet often
containing too much copper to lose, they
form very disagreeable product and one
that is apt to accumulate ON the hands oil
the metallurgist.
think the point OF sufficient importance
to mention plan that have adopted 81
the Parrot works, and which enc bles Us to
work up most of our shines at virtually nc
expense. Every one accustomed to the
management Of reverberatory furnaces
knows the large amount ofsticky loan and
clay that is required to lutte up the side
door Of the furnace, especially after thu
iambs are well burned out, SO that q wide
thus filled. Assuming q furnace to
smelt five charges day, thus necessitatinQ
the luting up Of thes door an equalnum
Der OF times, and allowing only SO POUNDS
Of dry clay to each luting-and thus is ial
below the average on old furnaces-it will
be readily seen that where from six to 9
dozen furnacee are in operation the amount
Now, on taking down the side door, all thii
clay falls down upon the fresh charge
which is piled just under the door, ani
eventually finds it's way into the furnace
where it adds a.serious amount Of barrel
quartz toa charge already probably too
siliceous. A careful trial proved that thu
shines would answer the same purpose al
the clay; and now, instead Of smeltinga tol
Or more per day at barren loan. we hav
replaced it with an equally satisfactor!
material, carrying 10 per cent. or more o
copper.
To return to the subject of concentra
tion. It ia impossible to furnish any figure
that shall apply to the different mills wit
any degree Of accuracy, but in order to Civ
q genersl idea OF the results obtained frou
those ores carrying q high percentage {
iron pyrites, which includes the greater par
Of the ores at present submitted to col
centration, l will submit the following fl
ures "a reasonable average:
Results of Concentration.
Per Ger
Original amount Of copper in the ore... y
Assay of concentrates from jigs............. II
AaAav nf CpnfFAfQn from vNnnQFA ~