IMPROVE- MENTS IN THE MANUFACTURE OF COPPER FROM COPPER ORES
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Theodor Fleitmann at the Office
of the Commissioners of Patents, with his Petition, on the 9th September
1862.
I, THEODOR FLEITMANN, of Iserlohn, in the Kingdom of Prussia, Doctor of
Philosophy, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF COPPER FROM COPPER ORES," to be as follows:-
This Invention has for its object improvements in the manufacture of copper
from copper ores, and is more particularly applicable in the manufacture of
copper from those ores which contain silver or gold, and which have as
impurities arsenic, antimony, and phosphorus, which, according to tho
ordinary roasting and smelting processes, are very difficult to separate entirely
from the copper. The copper ores employed are first ground to a powder,
then one part of such powder is subjected to a roasting process, and is ronsted
dead. The roasted product is mixed with the unroasted portion of the ore,
and together with suitable materials for producing a slag, such as silica, and
cinder of a previous smelting process, it is then subjected to heat in order to
be melted. The melted mass is run into water, and the product is ground to
powder. Part of this powder is subjected to a roasting process, and is roasted
dead. The unroasted and roasted products are then mixed, and together with
fluxing matters, such as silica and cinder or slag from a previous smelting
process, are subjected to heat and melted. The melted mass is run into water
and again ground to powder. The powder thus obtained when necessary is
divided into two parts, one of which is roasted dead, and then mixed with the

page_text: unroasted powder, and the mixture is melted as before. In this manner the
ore is again and again treated till the resulting sulphuret of copper is in the
condition desired. In each of these processes the quantity roasted and the
quantity left unroasted will depend on the quantity of iron present; the more
iron thero is present the greater is the proportion which is subjected to the
process of roasting. The sulphuret of copper obtained is ground to a powder,
is roasted dead, and moistened with a solution of alkali, for which either
carbonate or caustic soda or potash is used. In those cases where the quantity
of silver or gold present is important, then the same is to be extracted in the
ordinary manner before roasting the sulphuret of copper dead. The oxide of
copper is subjected to heat so as to melt the alkali, but not the oxide of
copper, which is then to be well washed in water. The product obtained is
mixed with powdered carbon (wood charcoal being preferred), and then
melted, applying either coal or carburetted hydrogen or pure hydrogen, which
is preferred to be done in a blast furnace of comparatively small height, the
interior of which is lined with fire-brick or fire-clay. The exterior is formed
with a double casing of iron, with a spiral air passage between the two
casings, so that the air passing through the passage may keep the brick lining
cool, but other forms of furnaces may be employed for smelting the oxide of
copper obtained by the process above described. When melted copper is
found to contain oxide of copper it is subjected to the action of hydrogen or
carburetted hydrogen, and this is conveniently done by allowing melted copper
to flow through a tortuous passage or pipe in one direction, whilst hydrogen
gas or carburetted hydrogen gas is caused to pass in the opposite direction, or
by driving the gas in contact with the melted metal. When the ores contain
copper and nickel, then an alloy of these metals can be obtained in the manner
above described in respect to copper.