History of Copper — Development of the Copper
Industry — Progress of Smelting Practice — Price and
Cost of Production of Copper — Copper Statistics.
=The History of Copper.=—Copper was probably the earliest metal
commonly employed by mankind. It occurs in the native condition in
various parts of the world, and the natural product thus required no
metallurgical treatment prior to use. Its malleability and the property
of being readily toughened by simple mechanical treatment were also
factors which account for the discovery of its general usefulness in
such primitive times.
Although silver and gold were possibly known even earlier, these metals
appear to have been employed chiefly for ornamental purposes, and as
tokens, rather than for general service.
The alloy of copper and tin, known as bronze, was the first metallic
combination in common use by man; its employment was so characteristic
in prehistoric times, that archæologists assign to one of the epochs
the name of the Bronze Age. As is well known, archæological time is
marked by a series of ages, in which the use, first of stone, then
of bronze, and ultimately of iron for the manufacture of tools and
implements, indicate the development of industrial culture. The dates
which can be assigned to those periods vary with the locality; the
races in the more Northerly latitudes being later in their development.
In our own country, the Stone Ages may be said to date from 3000 B.C.
down to 1000 B.C., and the Early and Late Bronze Ages from 1000 B.C.
to 500 B.C., and from 500 B.C. to the commencement of the present era,
respectively.
It is not unlikely that in many places copper was largely used during
the Stone Ages and before the Bronze epoch, since it was only after
the art of making fire had been discovered that it became possible to
manufacture bronze, whilst native copper could be fashioned without
the aid of heat. Metallic relics of the Bronze Age, in the form of
arms, ornaments, and domestic implements have been found in widely
distributed localities.
The mention of copper occurs in the Hebrew Scriptures, the metal
being termed _Nehosheth_, from the root _Nahásh_, to glisten. This
was translated as χαλκὸς (_chalcos_) in the Septuagint, and _Aes_ in
the Vulgate; the Greeks and Romans using the terms, however, both for
copper and for the alloys brass and bronze.
According to Pliny, the Roman supply was derived chiefly from Cyprus,
and the metal thus came to be known as _Aes Cyprium_, which was
gradually shortened to _Cyprium_, a name afterwards corrupted to
_Cuprum_, from which are derived our modern terms _Copper_, the German
_Kupfer_, and the French _Cuivre_.
Copper was well known to the alchemists, and inasmuch as it was largely
obtained from Cyprus, an island dedicated to Venus, it was considered
to be the metal specially sacred to the Goddess, and was generally
known by that name in their writings, and symbolised by the sign
[symbol: circle with plus sign underneath]. The production of metallic
copper on iron by the action of certain liquors from the Hungarian
mines and other localities, was likewise known to the alchemists, and
was a constant source of inspiration to them; the changes were regarded
for some hundreds of years as examples of the transmutation of the
elements, until Boyle showed that it was necessary to introduce copper
into such solutions before that metal could be precipitated from them.
=The Development of the Copper Industry.=—The mining and smelting
of copper ores on a primitive scale have been carried on from time
immemorial; these operations were certainly practised in Greek and
Roman days, and the deposits of Britain are said to have been known to
the Phœnicians so far back as 1000 B.C. Percy refers to the finding
of lumps of copper weighing 42 lbs., carrying a Roman inscription;
this metal was found in close proximity to mines in North Wales, which
yielded an easily reducible ore, and he concluded that this was smelted
_in situ_ by the Romans.
There are undoubted records of copper mining in this country in the
time of Edward III., and in that of Elizabeth; whilst the first
authentic accounts of copper smelting date also from the latter
period, relating to South Wales. It appears that one of the earliest
establishments was situated at Neath—a fact recorded in a publication
of 1602. The works probably existed for a century before that date,
and the copper smelters at Swansea were established about 120 years
afterwards.
The processes employed for the primitive smelting of copper ores
were, to a large extent, of the same nature as the crude operations
practised generally for the extraction of metals in remote ages and
by primitive races, as recorded from time to time by travellers and
explorers. The furnace-hearth was a hole in the ground, working usually
on oxide ores with charcoal or wood as fuel. This primitive furnace was
later developed, by the addition of walls for enclosing the charge,
until the “shaft furnace” provided with an air blast of some kind
was attained. The sulphide ores presented rather more difficulty in
their treatment, but the production of metallic copper from sulphide
materials by super-oxidation, in a process akin to the bessemerising of
to-day, was developed in Japan centuries ago, and has been described by
Professor Gowland.
It would appear that during the middle ages, the art of reducing
copper ores to metal on a comparatively large scale was practised
simultaneously in Britain and in Central Europe; first by primitive
methods similar to those indicated above, developing later by
successive improvements into the employment of small blast furnaces.
By about 1700, however, the methods diverged, and it is interesting
to note that the different styles of working then introduced have
persisted, until recent years, as the methods typical of these two
parts of the world. In Wales, where the well-known furnace coal was one
of the characteristics of the locality, as it still remains to-day, the
smelting processes developed along the lines of reverberatory practice,
for which such fuel is eminently suited, and this resulted in the
establishing of the representative Welsh process. On the other hand,
the enormous forests of Central Europe furnished wood suitable for the
making of charcoal, a type of fuel which necessitates close proximity
with the furnace charge, so that in these localities smelting was
carried out in the shaft furnace, which gradually developed into the
small blast furnace. At the present time, the solid fuel suitable for
reverberatory practice is only obtainable in very small quantities in
Central Europe, and the characteristic method employed there for copper
smelting is that in which small blast furnaces are used, except that
charcoal has been largely replaced by coke as the fuel.
It is probable that the early ore furnaces of the primitive
blast-furnace type in Britain were worked by Germans experienced in
that class of work, just as at a later period in the history of the
industry, Swansea coppermen were to be found in all parts of the world
teaching other nations their art. Gowland reproduces a letter, dated
January, 1583, protesting against the introduction of this foreign
labour, whilst a second letter, dated July, 1585, which is also quoted,
is of particular interest, as it gives evidence of a remarkable
knowledge of the art of smelting, and, whilst illustrating an important
feature of modern practice, indicates also the manner in which an
astute smelterman was able to work profitably with difficult material
so long ago as three and a quarter centuries.