The evening times. [volume] (Washington, D.C.) 1895-1902, 1901-07-06
GERMAN COPPER REDUCTIONS.
An American Consul General En-
plains the Methods Employed


plains the Methods Employed
In compliance with instructions from
the State Department. Frank H Mason,
United States Consul General at Berlin.
has sent to that department a most ex-
haustive report on the subject Of the re
duction Of copper ores in Germany. Mr..
Mason says:
There was mined in Germany in 1899
the last year for which complete stats
tics are accessibIe-723. 6I9 metric tons Of
copper ore. from which was produced "a
6S3 tons of copper. an average yield Of
80 per cent. Besides this Z.36I tons Of
copper were produced from imported
(mainly SPANISH ores, making the total
product 1900 tons, besides which Ger
many imported, in 1893. O.O21 tons of raw
and ingot copper and 1864 tons in 1900, Of
which last ct tons came from the Uni
ted States. The electrical industry of this
country alone consumes annually about
10000 tons of copper. whereas only about
5000 tons OF the yearly native product IS
eleCtTolytiC copper and therefore adapted
to certain electrical purposes Germany
produces therefore only One-thirteenth Of
the required amount of electroIytic cop
per and One-third of the general supply
for all purposes.
The copper ores of Germany are main
~ the sulphides, namely, ID 'Kupferkies,'
or chalcopyrite, containing from to 3
per cent OF copper; t2) ehaIcosin, or cop
per gaIena called in German 'kupfer-
CLAM. and 90 bOTnit. or yaTiegated cop
per ores, 'Buntkupfererz. OF these by
far the most important is the chaIcopy-
rite. which is found in the form Of hi
luminous coppeT-bearing slate (MergeI-
a. nj 4f
Gosiar in Frussian Saxony.
The production Of copper from all these
ores is accomplished by one of two gen.
eraI methods, known. respectively, as the
dry process troasting and smeiting). and
the wet process in which the metal is
leached from the ores with chemical So
Iutions and then precipitated by the ac-
ton Of scrap iron. what is known in
practical metaIIurgy as the German pro-
cess of copper production consists of
roasting and smelling operations is fol-
lows: First. roasting the raw ores; sec
ond, the smelling OF the roasted ores in
blast furnace, whereby is produced 'kup-
ferstein,' or crude copper matte-a mix
ture of sulphates Of copper, iron. silver,
and other metals and containing an av-
erage of 90 TO % per cent OF copper; third,
roasting Of 'kupferstein,' OF matte: and
fourth smelling and publication of the
roasted matte and the production thereby
OF raw or black copper tSchwarzkupfer),
which is subsequently refined by smelling
and further treatment to crude copper Of
IS to $50 Per cent purity, or by electroIysis
TO electrolytic copper
This general process is the one ordf-
nariIy practiced for reducing the bitumi-
nous cupriferous states (chaIcopyritcJ Of
he gfT
cisely described as follows:
The ores are first roasted in long. mar
now heaps or open-air hilns. in which the
fire is largely sustained by the bitUmen in
the ore. This is wholly consumed, and the
greater portion Of the carbonic oxide and
sulphur likewise expelled The roasting
requires considerable skill. in order that
it shall not be pushed too far. and thus
eliminate too much Of certain elements
which are essential to the success Of the
subsequent smelling operation.
This roasted material is smeIted in a
blast furnace, with or without fuxing
material, according to the composition
Of the ore. y hereby a large proportion
OF the impur.t Ties is drawn off in the
Stag, leaving the metals concentrated in
the 'KupfeTstein.' or crude copper matte.
which gives the following mean analysis:
Copper. 41-36 per cent; silver, -226 per. cent;
lead. -537 per cent; iron. q 325 per cent
Manganese, IS per cent; zinc. 3.7I per
cent; nickel, 3 per cent, cobalt, -2s2 per
cent arsenic, -0S per cent; sulphur, 25Sl5
per cent
when the sulphur eases are to be
utilized for the manufacture of suIphu-
ric acid, the roasting Is done either in a
small shaft furnace, called in this coun-
Try 'SchachtOefen' IN which case the
Kupferstein is broken before roasting
into small. Irregular humps. or It IS pull
verified and roasted in a special kind OF
oven or furnace invented by Geestenhof-
er and named after the inventor, which
has the disadvantage Of creating an IN
due amount Of dust, and is not there
fore generally used. BY this second
roasting process, the sulphur Is expelled
in gas which contains + to per cent of
suiphurous oxide (SO2) and which is
used in the usual manner for the manu-
facture Of suIphuTic acid, which. except
silver, is the most important by-product
OF this progressive reduction process
The roasting being finished the matte
which contains still copper ana silver in
combination with sulphur, IS smelted,
with addition OF quartz sand as fiuXiug
material This carries Of most Of the
remaining impurities.
which are changed and modified to meet
the varying composition Of the ores I'M
der treatment. there Is finally produced
the ingot copper known in commerce as
'Mansfelder Raffinad A
1t will be noted that Of all the foreign
metals. nickel IS the most difficult to sep
aratc from the copper, and il therefore
remains in greater proportions The rel
alive Importance Of the Mansfield district
Is shown Icy the fact that in 1897 there
was produced there l3.444 tons of copper,
2IU. .3S pounds Of Si,rsr, and lS.24S tons OF
suiphuric acid, 30 obtain which latter
product Us roasting / ..-.s and nine groups
Of Iead-lincd chan.o-rT. with a collective
capacity Of 914 cable yards were en-
ployed- The total revenue from the sale
of these products was 81 .6S9 6i9, and the
total cost Of production $Iu,agj, AL, leaving
q net profit Of S6Gi ,206
The wet process Of obtaining copper is
employed mainly with ores which are too
low IN grade 10 L. worked prontabIy by
roasting and smelling. 1t can be used
under favorable circumstances with ores
y hICh Contain as low as One-half Of ! per
cent 10 ] per cent 1f copper, and also for
reducing the cupTIfcTOUs slack which re
mains from the production Of zather met
ais 1t consists IN prCcipitating the cop
per from d vitrist or chloride solution by
means of scrap ron or other reagent-
The solvents principally used for this
purpose in Germany are diluted sulphuriC
and muTiItic aci.-- As the former is
largely produced t'y the dry process Of re
dUciHg copper, sUlphurjc acid Is usually
cheapest in the neighbOThOOd of copper
mines. and hence vitT!oi solutions are gen
orally used for the wet process In this
country MuTiatiC aClf producers Il chic
ride solution, and in the neighborhoOd Of
works which manufacture soda from com
mon salt by the Leblanc process. il Is
often sufficiently cheap and plentiful to
be economically used for teaching c0pper
ores and concentrates. In order to be