Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1888-05-27

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an interesting account OF the mode OF eX.
tracing the copper, and in the absence OF
technical terms any intelligent reader OF the
Dispatch VIII comprehend the process
The calcination IL the copper ore covers
the country for some miles with sulphurous
smoke fatal to vegetation, aud the impreg-
mated water kills the fish Of the river aud IS
unfit for use by man or beast. The land
owners aud small planters in the nelghbor-
hood keep up an incessant strife and annoy
ing lawsuits with the company, and have
succeeded in iorcog from the Cortes some
adverse legislation. A few months ago
strike occurred among the operatives. WORK
was suspended for three days. Angry
crowds assembled in the square. A collision
occurred between the mob and soldiers
The latter fred. About twenty men were
killed. All except the soldiers hastily dis
persed. This was on Saturday afternoon
On Monday work was resumed without eX-
plantations or concessions, and everything
has since gone on quietly.
A BRIEF ACCOUNT or TIE LOCAL TREATMENT
OF TIE RIO TINTO MINERALS.
After the mineral IS taken iron the mines
It is subjected to the process OF selection
/. C., It is divided into the following classes
viz:
/. Expectation Mineral.
.. Ordinary Calcin2tlon Mineral.
3. Rich Mineral for Blast Furnaces.
4 Natural Smalls.
l. EXPECTATION MtYFRAL.-Tbis ia bard
and compact mineral, averaging % per cent
copper and about 4S per cent. sulphur. ms
mineral IS exported principally to England,
where the sulphur Is manufactured into SUI
phuric acid and the copper subsequently eN-
tracted by either the dry or wet process
j. e., by fusion or washing.
.. CALClNATioN MINERAL.-This mlneral
resembles very much the aforementioned
class, inasmUch as it is very bard and com
pact, but Is much poorer Ia copper, contain
ing only from l.J0 10 go per cent, tne
sulphur being pretty much OF the same per-
centage az expectation minersl-from 80 10
10 per cent. This mineral is broken up into
small pieces Of uniform size on the spot and
Is formed into mounds or tcierds OF various
shapes and sizes and containing from 200 10
], 200 tons each. The tCierGS thus formed
are ignited with a triling proportion OF
wood, and I'm virtue 0i the sulphur present
continues 10 burn until nearly the whole OF
tnat element l. eliminated. During this Ope-
ration the copper l. converted from the IN
soluble into the soluble condition. and the
sulphur combining with the oxygen Of the
air IL allowed 10 escape In the form OF sui
phurous acid gus. When the mineral is
COMP, tely burned out, when tske5 place
from two to twelve mouths from toe date Of
lighting depending upon the size OK The
te.eTqS) il Is loaded up into wagons and
conveyed into suitable tanks. where II Is re-
peatedly and thoroughly tresed with fresh
water, when most OF the copper present Is
washed out. The solution containing The
Ii.
OF preclpltaiirg tanks filed with iron (gen-
orally pg-iron), when the copper inn iiatcly
begins to deposit on the same In beautiful
granular condition VARYING from one eighth
to Que quarter OF an in thickness, depending
OF course uuon tbe strength OF the liquor
under treatment and The time That It
Is kept in contact with the iron.
The copper thus precipitated is carefully de-
tached from The from and collected. II IA
then washed first with diluted sulphuric acid
$50 rs 10 remove any arsenic that may be
present. and theu with plentiful supply OF
fresh water. The washed precipitated Is
next dried at gentle heat 50 Is to eXpel
moisture, and IS subsequently stored in
strong canyasbags, when It - ready for the
market. The best class Of prccipitate IN
this state contains from 90 per cent. TO So
per cent. OF copper, and from 0 % per cent.
10 0.45 per cent. arsenic the balance being
iron, oxygen. silica, and moisture.
3. RICH MINERAL FOR BLAST + URNACEs.-
This f. generally hard mineral. containing
from : to ID per cent. copper and from 30 to -
per cent. sulphur. 1t Is formed into teleraS In
exactly the same manner as the class pre-
viousiy described, and takes practically the
same time to burn out. When thoroughly
calclned u Is semitic the blastiurnaces, where
It Is mixed with aboutO one third o. rs weight
q quartz or secou, mineral and smeied,
the result being the proc uciiOn Of q" llegu-
lus or matte" VI from 81 10 30 per cent cop
per and q Stag containing only about o. per
cent. OF tho lme element. The former IL
sent 10 the cempany's works in England,
where It is manufactured into ing0t or cake
copper. and the latter discarded rs Yalueless.
4. NATURAL SNALLs-PToduccd during
tho process Of extraction Of the mineral and
the various handling OF the same. II is too
fine TO burn in the ordinary way, and the
cost 81 constructing Yulus for calcining
would probably be greater than the value OF
the copper recovered. IL Il therefore mixed
With washed. burnt mineral, and formed into
heaps Of about three metres in thickness and
covering large area Of ground. A syste-
matte arrangement q air channels are intro
duccd for the admission OF air foe the Dur-
pose OF oxidation. After brief period de-
com position sets IN, rendering portion 81
the copper soluble, which Is washed out by
pumping fresh water over the heaps from
time to time, and the copper thus obtained
Dreclntated IN the Ordinary way. IN the
course OF a year or so about 10 per cent. OF
the copper contents Of the fine mineral is OBJ
tanned, the remaining 90 per cent re-
curing q much longer period for its elimi-
nation. We have at present about seven
million tons OF mineral in different parts Of
the mine undergoing this kind OF treat
meut, and from which wo recover annually
from 1000 10 1000 tons Of metallic copper.
HUELyA, SPAIN, May, 1888.