Introduction.
A.D.
1500.
Enlightenment
in the Elizabethan Era.
Calamine
Brass.
Summary
of the Commercial Development in the Seventeenth Century.
Copper
Smelting and Refining in the Eighteenth Century.
More
Commercial Considerations.
Smelting
Zinc, early Eighteenth Century.
Some
Metalworking Processes developed in the Eighteenth Century.
Review
of the Eighteenth Century.
The
Growth of Copper Smelting and Refining in Swansea, Nineteenth Century.
Yellow
Metal
Fresh
Fillip to Zinc Smelting.
Sidelines
on Copper Smelting.
The
Welsh Process of Copper Smelting.
Ships.
Countries
from which ores were imported 1901.
Copper
Ore Wharves.
Handling
Cargoes and Consignments
Birmingham-Copper
and Brass in the Nineteenth Century.
Review
of Copper and Brass in the Nineteenth Century.
ACKNOWLEDGMENTS.
REFERENCES.
The main purpose
of this essay is to trace the metallurgical development of the copper and brass
industry from Elizabethan times to the Edwardian era. A cursory glance at
historical authorities on the various facets of the industry reveals that
detailed metallurgical information on the mining, smelting and refining of
copper and zinc ores and their subsequent manufacture into wrought shapes is
woefully lacking between 1600 and 1850. (1-4)
Indeed, it would almost appear that the recordings of Agricola (5)
served as the bible of the industry until comparatively recent times.
On the other
hand, the histories of the establishment and economic growth of the various
principal firms associated with the industry are not difficult to trace, largely
because of the legal records involved and because some of the detailed account
books and balance sheets have been examined and reported. (1,2,5),
As yet, however, no corresponding records have been revealed of the
technical side of the industry; the specialised knowledge and experience
acquired in this country and abroad by the master miner, chemist, smelter and
refiner, by the smith and the brass-melter or by the hammerman and wire-drawer,
appear not to have been noted in technical detail at the time. These trades were
all, in fact, closed shops, the secrets being handed down verbally from father
to son; indeed, traces of that arrangement remained in the industry almost to
the present day, especially in the labour agreements of the more backward
portions. In addition to this, particularly in the Swansea district, great
rivalry existed between the three principal smelting and refining firms;
although the sites were adjacent, technical know-how was not allowed to be
divulged, and this attitude was physically enforced by a formidably high
boundary wall and by the river Tawe which separated the three works.
Fig. 1.
Agricola: Blast furnace. (Figures
not included for copyright reasons)
It is
proposed, therefore, to attempt to record in rough chronological order the
highlights of metallurgical improvements made in the industry over this period
and to outline the interplay among the areas of the country which were
intimately associated with this growth, namely Cornwall, Swansea and Birmingham.
In De Re
Metallica Agricola records in employed for extracting copper from ores, some of
which also contained lead and silver. (5)
These methods are referred to briefly here
metal extraction in Europe and form a starting point for developments in
Britain. Following various methods used in Saxony and the Joachimsthal area, he
describes hand breaking, sorting and grading of the ores. In the case of gold
and tin ores, wet stamping, wet grinding and washing were regularly employed,
and even in Cornwall in those days concentration of tin ores was certainly
carried out.
The concentrated
copper ore-a sulphide-was then roasted with faggots and in some cases allowed to
lie in the open air for many days to get softened.
After the roasting treatment the formation and carried out in a small
shaft type blast furnace chamber above (Fig. 1). Air was forced in through a
bronze or iron tuyère and in the remained open, the matte running out into a
forehearth consisted of three parts roasted copper ore, to which were
added such other concentrates and slags as were available.
This was run down into the forehearth, and the resulting cakes were
water-quenched and then roasted. Four parts of roasted cakes to one part of
crude pyrites were remelted and again run into cakes. Some crude blister copper
may have resulted from this operation, but if not the cakes were again roasted
and remelted with a soft slag, these operations being repeated until blister
copper was obtained.
Fig. 3.
Agricola: Testing refiners . (Figures
not included for copyright reasons)
Agricola in
Book XI describes vividly and accurately the refining of the blister copper and
also other techniques of liquating out any lead- and silver-bearing
constituents, thus leaving the copper cakes in a "dried" condition.
The furnaces used were really little better than smiths' hearths built in
hemispherical form, lined with a mixture of silica, clay and charcoal and
capable of taking one 100-400 lb. of copper. A powerful air blast was directed
on to the surface of the metal from a series of one to three copper pipes (Fig.
2). The furnace was preheated with live charcoal, about 200-250 lb. of blister
copper was added if of normal quality, more charcoal was added, and pieces were
also put into the tuyères, presumably to preheat the air somewhat. When the
copper was molten the master pushed an iron bar into the middle to oxidise the
copper with a blast of air, the slags were partly cleared, and an iron bar was
dipped in. If the copper was good,
it adhered easily to the bar (Fig. 3) and was stripped off as a thin, continuous
layer of high malleability.
If, however, the
copper was not good, the slags were drawn off two or three times if necessary,
and then the master inserted a hazel stick into the crucible and stirred twice.
The copper was then removed by an ingenious process of top solidification. Water
was poured on to the surrounding brickwork and thus heated ran on to the molten
metal, accelerating the formation of a crust of solid copper on the surface.
This crust was removed with a wedge-shaped iron bar, the cake immediately
quenched in water and the process repeated (Fig. 4). By this means up to
thirteen cakes of thin, uniform quality could be made. The first one or two
contained some slag and were usually remelted. Precautions were taken to avoid
stones, bricks, pieces of iron or calamine from the walls and hood falling into
the crucible and contaminating the charge. In addition all copper dust and
copper flowers were taken from the water tub weekly.
Fig. 4.
Agricola: Cooling copper cakes . (Figures
not included for copyright reasons)
Fig. 5. Arms of
Mineral and Battery Works, 1568
This necessarily
brief description of the state of the art in Europe in the sixteenth century is
sufficient to reveal gross waste of charcoal, which was the only fuel used,
probably very inefficient recovery of copper (although slags and dusts were
recycled many times), and that quantities of the order of 2-3 cwt. only were
handled at a time. In addition, particularly in the operation of smelting
copper, the working conditions must have been appalling, and in the refining
operation the method of top solidification of copper by means of warm water must
have resulted in a very low furnace life.
Up to this time
Britain had, from the days of the Phoenicians and especially in Roman times,
mined and extracted tin, lead and copper from their ores, but the ventures do
not appear to have developed in any way. In the time of Elizabeth I, however,
Lord Cecil advised her to foster this industry. Consequently Pettus (7)
reports: "About the third year of Queen Elizabeth, 1561, she by the advice
of her Council sent over for some Germans experienced in mines, and being
supplied, she, on the 10th October, in the sixth of her reign granted the mines
of eight counties to ... Houghsetter." Besides this, other Germans were
encouraged to invest capital in this country to teach the art of smelting copper
and making brass, such men being Christopher Shutz, Ulriche Frosse and Jochim
Gaunse.
The status of
such companies in Elizabethan England was visually enhanced by granting coats of
arms, of which a typical example is given in Fig. 5.
The arms and
blazoning of the Society of the Mineral and Battery Works 1568 are blazoned
thus,: "Silver with a mount vert. A man working within a mine, with two
hammers and a lamp, all in their proper colours on a chief azure. A cake of
copper between a bezant and a plate on a wreath silver and azure. A demy man
(called in Dutch the schicht master) with an escutcheon on his breast or and
azure per bend inverted; in one of his hands an instrument called a wedge, and
in the other hand a compass, gold mantled; silver doubled azure, supported with
two men, the one called the hammer-man, with a hammer on his shoulder; and the
other the smelter with a fork in his hand; all in proper colours."
In 1564 an
Anglo-German partnership began mining and smelting operations at Keswick, and in
1568 this company was incorporated into a joint-stock company by a royal charter
which created the Mines Royal.
During this
period Ulrich Frosse smelted copper ores at works which he set up at
Perranzabuloe in Cornwall as well as at Keswick and in South Wales at a later
date, so that his travelling must have been a heavy burden in those difficult
times. It soon became apparent that the quantity of fuel required would favour
the location of smelting works near the mines of "sea coal," and not
merely where charcoal could be got. It was only at a much later date, when the
development of steam pumping engines of the Newcomen type led to a large
quantity of Welsh coal being brought to the Cornish mines, that it was again
seriously suggested that it would pay to smelt copper ores in Cornwall near the
mines.
In the winter of
1582 Ulriche Frosse, who had been given management of affairs at Neath (probably
at Aberdulais (8) , reported that he was able to smelt 24 cwt. of ore
every day with one furnace. It seems possible that this was achieved by using a
reverbatory furnace. If so, this is the first instance of such furnaces being
used in Britain for smelting. But recurrent financial difficulties and repeated
and long delays in the supply of ore led to the abandonment of the venture. The
first record of the design of a reverbatory type furnace was given by
Biringuccioe in 1540. Some interesting information as to the knowledge which
these early German smelters possessed can be gleaned from the correspondence
which they have left behind.
Thus on 7th March
1586 Ulriche Frosse wrote: "Have in readiness as much copper roste and
blake copper as will mak a 20 tonne lotte of good fine copper. "We are able
to melt it with two fornisses in the space of 40 weekes the quantitie of 560
tonne of ewre if we might have it.
"Send such
ores as you have, not caring what ore it is, when you do send, if you can, send
all sorts; the better it will melt and with more profits."
They also had clear ideas as to the
various impurities in copper ore; for in a description of operations at the
Keswick works in 1581 there is an elaborate discussion of the "ix infectyve
and evil Humors. 1 The first one mentioned is sulphur= "a
mynerall substance w'ch verie quickly taketh fire, and wilbe consumed in smoke
by blast"; it leaves the copper black and brittle, "so that it wilbe
broken w'th the hammar, in manner like glasse." Arsenic was also said to be
"consumed w'th fire into smoke, w'ch is a vere daungerous ayer or savor,
and by his force maketh the copper white and brether than the sulphur
doeth." Antimony, another impurity and a "great let and hinderer to
the copper in smeltinge," was eliminated by heat. "Vitriall" was
removed by "stamepinge the copper ure into powder and by rostinge the same
powder ... before it be smolten, and then letting water passe through the same
roasted powder, the water doth not onllie carry the vitriall from the powder or
ure, but also carrieth w'th it the burnt powder or sinder of the sulphur,
arsenicque, and antimony, whereby it so clenseth the ure that when it cometh to
the smeltinge the copper cometh forth easelie, w’thout such quantitie of
slagges or drosse, as otherwise woulde be, if the ure were not rosted and the
vitriall in the manner taken from it; thus is the vitriall, of an enimye made a
friende." Other impurities, such as iron and black stone (the substance in
which the ore is embedded when it is taken from the ground), gave rise to much
difficulty in smelting, but the remaining materials, 11calcator" (oxide of
iron), alum and spar, are mentioned as being "least hurtful to ye
copper."
Jochim Gaunse,
who was in charge of the works at Keswick, was quite sure that he knew how to
deal with all these impurities in order to obtain good copper; besides, it is
interesting to notice, he intended making use of these by-products to the
"great bennifitt of the Companie." Not more than eight or nine "seks
of chare coles and thre horslod of sea coles" were required for smelting 24
cwt. of ore.
The methods
employed by the Elizabethan smelters were by no means perfect, and during the
next two centuries a great deal of attention was paid to improving the processes
in order to get rid of the various impurities in the ore.
The elimination
of the various impurities from copper were of infinite importance to the brass
manufacturer and the brassworker, for the quality of brass depended to such a
great extent on the kind of copper employed in its composition. Brassmaking
was in those days a laborious and costly operation, since it was made by a
process known as cementation.
In the sixteenth
and seventeenth centuries calamine was mined in Somerset and Nottinghamshire by
the Mineral and Battery Works, and an interesting account of the methods
employed in the former county was given in 1684. (14)
The method of
making "calamine" brass was described by Pettus.' "In one oven
they set eight pots or pipkins at once, and let them be warm and hot, and when
they are so, they take them out quickly and put the calaminaris in them, also
they have a shovel made on purpose, that therewith they may take up and know how
to distribute near 46 pounds in such eight pots. Then they lay in every pot upon
the Lapis Calaminaris eight pounds of small broken copper pieces, and set in the
pots again, and then let them stand nine hours in great heat, and in this nine
hours are to be taken one heap and a half of Coals, and when such coals are
burnt out, then stir the stuff in the pot with an iron."
According to Houghton, (15)
brass plates for wrought metal work were composed of about two-sevenths fine
copper, four-sevenths calamine, and one-seventh shruff or old plate brass. The
mixture was put into pots, which were then set in the furnace; after being
heated for 10-12 hours, the contents of eight to ten of them was poured into a
larger one (probably what at a later time was called the king pot).
When the whole
mixture was ready, the dross was skimmed off and the brass was poured between
two stones "of a tun weight or more," each of which was elevated at
one end. The moulds being filled, they were placed in an upright position and
the metal was allowed to cool, and so a plate of about 70 lb. weight was
obtained.
This method of
making brass was carried out with slight variations right down to the nineteenth
century, and as late as 1858 there were calamine furnaces in use in South Wales.
(3)
During this
period, while dogged technical perseverance continued, certain economic and
political repercussions also had a bearing on the growth of these associated
activities. The companies which were floated during this time had been given
extensive privileges in the reign of Elizabeth and the government was always
ready to expand and protect their powers of monopoly, with the consequence that
they had won a firm financial footing in England by the end of the reign.
Following this, however, various changes led to an abuse of the legal monopoly,
and consequently state assistance was sought and obtained to prevent the
importation of competing commodities. This arrangement was much to the detriment
of the pinmakers and wire-workers of Birmingham and elsewhere, who were
compelled to buy their raw material from the Mineral and Battery Works. In
addition to this, after the Civil War copper mining was neglected because the
shareholders clung to their privilege, and consequently the industries were at a
standstill for almost thirty years. State monopolies had, as a method of helping
industries to establish themselves, outlived their usefulness, and so by the
Mines Royal Act of 1689 and 1693 these restrictive monopolistic rights were
abolished, thereby freeing anyone to mine copper. In addition, the mining and
working of calamine and manufacture of brass were allowed to lapse. With such
technical improvements as an increase in the supply of ore and improvements in
the technique of smelting, and also a growth in demand, the way was open for
private enterprise, and several important companies were quickly formed. The
copper manufacturers, however, had for a period experienced some difficulty in
disposing of all their output and successfully approached the government to
obtain permission to export such surplus copper duty free. In addition they also
pressed to be allowed to use copper for the manufacture of coinage, and a little
later several brass concerns were founded. The demand thus created quickly
solved the marketing problem of the smelters.
Meanwhile a
copper smelter operating at Redbrook, Gloucestershire, had in the years 1685-8
discovered improved ways of smelting lead and copper ores by using coal instead
of the charcoal which had hitherto been generally used. (10) This
development so cheapened production of these metals that it enabled Britain to
be competitive with European and Scandinavian producers for many years to come.
This development had a most important bearing in the Swansea area, since it
enabled one ton of copper ore to be smelted with three tons of coal. In
addition, as we shall see later, the "free burning" Swansea coal was
found to be eminently suited when mixed in varying proportions with the coking
coal to reduce copper ores by what ultimately became known as the Welsh method.
Besides this development it became more and more attractive to carry out the
smelting in the Swansea district by shipping the ores from Cornwall, the return
voyage being made with South Wales coal for operating the pumping engines, which
by that time had been developed and were becoming more necessary as the mines
became deeper and natural drainage less practicable.
Some of the
Metalworking Processes developed in the Seventeenth Century Towards the end of
the seventeenth century rolling mills came to be used instead of battery mills
for flattening brass and copper ingots. For instance, there was a rolling mill
at Dockwra's works in 1697,(15) and in the early years of the
eighteenth century an extensive rolling mill was erected at Maidenhead on the
Thames, while about the same time there was one at the Mitcham copper works,
where sheets were prepared for coinage. But, of course, the process of battery
continued to be used for hammering the round plates of metal into pots, pans and
similar articles until about the end of the eighteenth century.
Fig. 6. Ruins of
Mines Royal Works at Neath, .
(Figures not included for copyright reasons)
The other main process of the early
metalworkers was wiredrawing. Prior to Elizabethan times wire was manufactured
in a most primitive fashion. Men sat in swings opposite each other with a thin
plate of brass attached to a girdle fastened round their waists, and then by
stretching forth their feet against a stump they shot their bodies from it,
closing with the plate again; and so on until it was stretched into wire. This
method, however, was superseded when wire works were set up at Tintern, where
power was obtained from water wheels. This was an essential part of the monopoly
of the Mineral and Battery Society; so it was not until near the end of the
seventeenth century, when its powers decayed, that other works were erected. A
description of wire-drawing in one of the new works in 1697 is given by
Houghton. (15) Plates of
brass weighing about 70 lb. were cut into seven or eight strips, and these
strips were elongated on the rolling mill to the desired thickness, the metal
being occasionally annealed to keep it soft and pliable. The strips were next
cut into many long threads, and were drawn through holes in iron to such sizes
as were required. It is interesting to notice that this method of making wire by
slitting from strips is still operated to a very limited extent.
Reverting for a
moment to the cradle of Welsh copper smelting, Sir Humphrey Mackworth
re-established this at Melincrythan near Neath in 1695 and promoted the Company
of the Mine Adventurers in 1698. Subsequently in 1713 a new company was formed
to manufacture articles made from copper, brass and lead, such as brass battery
kettles and wire. The various mills were laid out in his grounds and linked by
an ingenious system of watercourses to provide motive power.
Fig. 7. Ruins of
Mines Roval Works at Neath .
(Figures not included for copyright reasons)
Smelting was also
commenced on land adjacent to the Old Abbey at Neath, probably somewhat earlier
than 1700, by the Mines Royal, who continued to operate the plant for about a
hundred years (Figs. 6 and 7).
In 1717 Dr. John
Lane and Mr. John Pollard built the Llangavelach Copper Works at Landore,
Swansea, which was almost certainly the first copper smelter directly associated
with the town. The works, shown in Figs. 8 and 9, consisted of a double house 80
ft. x 40 ft. x 20 ft., a double house 36 ft. x 40 ft. for calcining, another
round house, twenty furnaces for smelting copper, lead and silver, a refinery
house, accounting house, smith's forge, laboratory, test house, rod mill, blast
house and two other refining houses.
In 1726 Dr. Lane
and his associates became bankrupt with the breaking of the South Sea Bubble;
but smelting continued, so that although only some forty men were employed the
costs of production were some £40 less per ton of copper than at Hayle in
Cornwall. About this time Neath had 100 workers, but by mid-century half of the
copper and other ores were claimed to be smelted in Swansea.
As an example of
the trade at this time, reference to the balance sheet on 31st December 1745
shows that on the assets are the following items:
5 copper teaches
at Lisbon. 9 tons of metal at Dublin.
15 tons of
battered copper to London. 78 oz. of silver in the works.
11 tons of
battered copper at the works.
7 tons of fine
copper in London at £1 12 per ton.
In 1794 the Mines
Royal at Neath Abbey had 1277 tons of ore in stock, and 230 tons per week of ore
were smelted to give 18 tons per week of copper. These operations were
apparently carried out on 38 furnaces and used 315 tons of coal. 399
Fig. 8.
Langevelach Works, 1845 .
(Figures not included for copyright reasons)
More Commercial Considerations
During the latter
part of the eighteenth century the smelting companies had become so powerful
that they were able to prevent new undertakings being formed and also to impose
low prices on the Cornish miners for their ore and, on the other hand, high
prices on consumers for their cake and other manufactured copper. The
discovery and opening up of several copper mines in Anglesey, however, led to a
period of economic instability in the industry, and after bitter competition
between the two mining centres, a scheme was put forward on 18th July 1786 by
John Vivian (deputy governor) proposing the formation of the Cornish Metal
Company. This was a buying and selling concern with power to unify the output of
the mines. John Vivian showed after detailed investigation that the average
difference between the standard manufacturing price and the market price was £14
19s. l0d. per ton. By transacting the business on the lines above at a
differential of £3 15s. per ton a saving of some £47,215 per annum was
claimed. Additional savings were also claimed by the elimination of internal
competition among the eleven mines and their amalgamation to form six mines.
More economic working enabled them to cope with foreign competition for export
markets and the elimination of the merchant or middleman of this country.
Fig. 9. Works at Glasmount (1850), after T. W. M.
Turner .
(Figures not included for copyright reasons)
The main markets
of that time which determined the price of copper were the Indian contract, the
Birmingham market price and the London market. This particular association of
the Cornish miners, however, was fairly short lived, and it seems to have died
out about 1791. The South Wales smelters, however, continued to act as a
combination, and during the early nineteenth century the Association of Copper
Smelters of Swansea was organised, "on the one hand for the purpose of
keeping the price of copper ore and regulus low and on the other hand for
keeping up the selling price of tough and other kinds of copper." Meanwhile
in Birmingham the Birmingham Mining and Copper Company was formed by consumers
of copper as a co-operative venture to purchase mines and establish smelting
works for supplying their own needs. The success of this venture was followed by
the formation of other companies in Birmingham, notably the Rose initiated by J.
Gibbins and the Crown and the Union, each of which operated smelters at various
times in the Swansea area.
During this
period another important personality should be mentioned, namely Thomas
Williams, who floated two important companies to mine the copper ores in
Anglesey and subsequently smelt them in Swansea.
In 1738 William
Champion took out a British patent for the invention of distilling metallic zinc
from calamine by reduction with charcoal or coal. It is, however, reasonably
certain that in India and China smelters had distilled metallic zinc some
centuries earlier, but the knowledge had not permeated to central Europe,
Scandinavia or Britain. Whether, therefore, Champion had heard of the art in
Bristol from East Indian traders or had independently discovered the technique
is not known. The zinc manufactory he established at Bristol had an output of
200 tons per annum and the quality of the metal produced appears to have been of
a very high order, for the manufacturers of Birmingham and Wolverhampton, who
used large quantities, declared that it was as good as any brought from the East
Indies.
Strangely enough, the manufacture of
metallic zinc at Bristol did not lead to an immediate change from making
calamine brass, and it was not until 1781 that the direct alloying of copper and
spelter was patented by James Emerson. It may be possible that up to that date
the cost of metallic zinc, and hence alloying with copper to make brass, was far
greater than via the calamine route. Even then the new method only came very
slowly into use.
During this
period brass and copper were cast in the form of billets and cakes in moulds
made of stone brought from "St. Maloes" in France.'" The billets
were hammered and then drawn into wire, while the cakes were flattened by
hammers, usually driven by water power.
At the beginning
of the eighteenth century there were at least two brassfounders in Birmingham,
Henry Carver and Walter Tippin, but by the second half of the century the
process of casting was well known, and innumerable articles were manufactured in
this way. The town was particularly adapted for this process, since in its
vicinity there was a good supply of the special foundry sand necessary for
casting.
In the last
thirty years of the eighteenth century the new process of stamping came into
use, and it has played a very large part in the brass and copper industries
ever since. It was the setting up of rolling mills that opened up the way for
the extensive use of this process and in fact gave rise to the stamped brass
trade. John Pickering, a gilt toymaker of London, was the first to see the
possibility of stamping certain articles from sheet metal, and in 1769 he
obtained a patent for a limited application of this new process.
This was only the
first use of a very important process, the possibilities of which were
recognised by Richard Ford of Birmingham when, a few months later, he applied
the principle to the making of such articles as saucepans, warming pans, basins,
ladles and plate covers. His method was to use "two implements called dyes
placed under the hammer of a stamp or screw of a press, the one being concave,
the other convex, which by the pressure of the hammer or screw forced into the
dye, the shape or the form of the thing designed is accomplished." A few
years later another Birmingham man, John Smith, applied the process to the
manufacture of buttons and so revolutionised the trade, for up to this time
button-making had been a tedious business, since the designs on them were
engraved laboriously by hand. Great economy resulted from this invention, for
the stamp gave the form to the button, and the press the decorative relief on
it. Two other Birmingham manufacturers, John Marston, brassfounder, and Samuel
Bellamy, engraver and diesinker, were associated with the new process, and in
1777 they obtained a patent for stamping hat and cloak pins and various
ornaments for furniture. Finally, in 1779, William Bell invented a new way of
"affixing impressions from dies upon gold, silver, or metals by means of
rolling cylinders, on which such dies are engraved, which would be to the great
benefit of trade, particularly to the buckle, button and toy
manufactories." The new processes were widely applied and used for manufacturing
many household and other articles in copper and brass.
Another process
which came into common use towards the end of the eighteenth century was
cladding copper with silver, and this too was of particular importance for the
button, buckle and toy trades. The credit for the invention is usually given to
Thomas Bolsover of Sheffield, who in 1743 showed how silver could be rolled on
to copper in the manufacture of buttons, snuff-boxes and other light articles.
This idea, however, was not a commercial success in his lifetime; but another
Sheffield manufacturer, Joseph Hancock, took it up later on and employed it in
the manufacture of candlesticks, teapots and similar articles. Perhaps allied to
this new method, which came to be used extensively in the button, buckle and toy
trades, was one which John Bootie patented in 1768 and which dealt with the
tinning of copper and brass vessels such as ships' kettles and kitchen
furniture.
Thus we may summarise the close of the
eighteenth century by saying that it saw the firm establishment of Swansea as
the copper smelting centre of Great Britain, the bulk of the ore still being
obtained from Cornwall and to a smaller extent from Anglesey. Meanwhile in
Birmingham the metalworking skill of the people had been turned to the
manufacture of small articles of brass and copper, and the town population at
that time was strengthened by the arrival of numerous dissenters who brought new
ideas, so that by the mid-century Birmingham was the most important centre in
England of the brass and copper manufacturing trades. This business was guarded
with considerable acumen, and in 1780 a severe blow was given to the Association
of Brass Manufacturers by the Birmingham manufacturers establishing a
co-operative concern to make brass for themselves. As indicated earlier, they
also safeguarded their interests in copper smelting. So far as trade was
concerned the home markets had been completely dominated, and copper and brass
in all cast and wrought shapes were exported to Europe, India, Africa and
America.
In copper alone
the part played by John Vivian throughout the latter half of the century was
very significant, although his firm did not reach its full prominence until the
nineteenth century. About thirty years before his attempt to improve the
position of the Cornish copper producers in 1786 he had been one of the original
partners in a firm he set up in the year 1754 to smelt copper ores near his home
in Cornwall. This was begun at Entral, near Camborne, but soon removed to Hayle,
where coal was being brought in. The Cornish Copper Company's smelting
operations with 4000-6000 tons of ore annually were carried on there until about
1818, giving the name Copperhouse to a small town, and Vivian remained the
moving spirit even after the commencement of his Welsh works following the
Cornish association of 1786-90.
Thus it was a man
with many years of experience in copper smelting who finally threw all his
weight into the enterprise in Wales with the certainty that the industry could
best develop there, and not only founded a dynasty but brought British copper
smelting to the threshold of its greatest period. Two other Cornish enterprises,
those of Williams Foster & Co. and of Pascoe Grenfell, followed the example
of Vivian, and the long competition began which was to stimulate the perfection
of the Welsh process.
This very healthy
state of the industry as a whole in Great Britain at the beginning of the
nineteenth century led to further capital being invested in copper smelting and
consequent further expansion in the copper trade. At this period many works were
erected near those coal districts which it was supposed would best supply the
proper fuel for smelting at a fair and reasonable charge, together with ensuring
certainty and continuity of supply of the ores. This in practice meant one
district only, namely the Swansea valley of the river Tawe. It was estimated
about this time that three smelter works, each consisting of some fifty
furnaces, might smelt and refine about 10,000 tons of copper per year.
The growth of the
industry in the nineteenth century is probably best typified by selecting one
works only, say Vivian & Sons. (12)
This company was formed by John Vivian, who formed the Cornish Mining
Company in 1785. Subsequent to the dissolution of that company he moved to
Swansea and became interested in the copper smelting works at Penclawdd. Mr.
Vivian's son, John Henry, was sent to Germany, where he studied at Freiberg
University and became the favourite pupil of the geologist Werner and of the
chemists Breithaus and Lampadius. He also made an extended tour of Germany,
Austria and Hungary, returned to Wales, and finally took over the management of
the copper smelting works at Penclawdd in 1806.
It was soon clear
that this establishment could not be a success, partly since it was based on a
shallow estuary of the river Loughor and was remote from the centres of coal and
commerce. Subsequently in 1809 freehold property was purchased on the river Tawe
about a mile above the port of Swansea, and on this ground was erected the Hafod
smelting works and mills. An approximate estimate of the labour force required
for this venture was made in 1810. The number of furnaces, together with the
number of men required to man each furnace, was as follows:
Of which there
were: -
4 Chargemen, 1
Coalman, 1Metalman, 1 Slagman, 1 Limeman
, 2 Bricklayers, 1 Smith, 1
Carpenter, 1 Refiner, 1 Argent, making a total of 50 men.
On the more
personal side and well illustrating the status of the individual and the
exclusive nature of his vocation one may quote here an agreement drawn up on
26th July 1811 between William Howell and J. H. Vivian for the exclusive service
of the former as a refiner or smelter of copper. This agreement was to be for a
period of 21 years, and no disclosures of the art or mystery of smelting or
refining of copper were to be made except to William Howell's own children. In
return for this he was to receive a weekly salary of 30s. plus 2lb. of candles
plus 1 wey of coal plus £10.10s in lieu of a house and garden.
Fig. 10. Hafod in
1840 .
(Figures not included for copyright reasons)
The plan of the
works was arranged so that the greatest economy in working could be ensured,
furnaces being considerably larger than those formerly used and designed to
obtain the greatest amount of work consistent with good and economic smelting.
To meet the constantly increasing availability of copper ores from Cuba, Chile,
Australia and all parts of the world, the smelting works were steadily increased
until towards the end of the century they became the largest in Europe. In 1839
Mr. J. H. Vivian leased the ancient copper works and mills of the Governor and
Company of Copper Miners in England at Margam and also the rolling mills at
Upper and Lower Forrest, also powerful steam mills were constructed for the
rolling of copper at Hafod. The works had already a vast number of chimney
stacks, as can be seen from Fig. 10. In fact, the appearance of the works from
outside is little different at the present day, over 100 years later (Fig. 11).
Fig. 11. Hafod in
1952
Up till about
1842 the firm had not embarked on any other trade apart from that of copper
smelting and rolling, and an essential part of the rolled copper trade consisted
of sheets for sheathing ships. But in 1832 Mr. George Frederick Muntz of
Birmingham had taken out his well-known patent for the manufacture of brass
consisting of 60% copper and 40% zinc, together with the adventitious presence
of a small proportion of iron. The great merit of this alloy was that in
addition to being easily hot rolled and capable of accommodating certain chance
impurities introduced in the copper it had a relatively high corrosion
resistance and was well suited to the sheathing of wooden ships. Because zinc
had at that time become considerably cheaper in price this alloy obviously cost
less than pure copper. Consequently it threatened to entirely supersede and take
away the important consumption of copper for sheathing purposes. Although Mr. G.
F. Muntz did, between 1837 and 1842, carry out these alloying and rolling
operations in Swansea, yet he transferred them back to Birmingham by the latter
date. Messrs. Vivian and Sons saw the dangers arising from the potentialities
of this new alloy and after prolonged litigation took out a licence under the
patent of G. F. Muntz and commenced the manufacture of the yellow metal at the
Hafod works.
The immediate
consequence of this development was that they became much more interested in the
manufacture of zinc, and in 1844 this was commenced on a small scale in Swansea
by adopting the method known as the English Process. The ores were reduced in
large conventional shaped vertical retorts arranged round the inside of a
circular furnace. These furnaces, however, produced only about 1 ton per week of
zinc for an extravagant expenditure of fuel-six times as much per ton being used
as in 1870. Because of this inefficiency Mr. J. H. Vivian's eldest son, Henry
Hussey Vivian, after studying at Eton, Germany and Cambridge, took over the
management of the smelter works. He was thus able to introduce the best type of
furnaces as used in Silesia and Belgium, which resulted in a considerable fuel
economy. The Old Forest copper works, which in those days still maintained the
circular arrangement of copper furnaces (Fig. 12), were purchased and converted
into a zinc smelter.
Following these
developments and in about 1868 some thirty German workers under Mr. Daehne,
their German manager, were introduced to Hafod Works to produce zinc, and
following further improvements in their zinc smelting practice the works were
able to compete with the best Continental works, despite the higher wages then
current in Great Britain.
Parallel with
this development in the industry, copper ores were being received in this
country containing gold and silver, and as a consequence in 1848 Mr. Hussey
Vivian undertook to extract silver from copper under the patents of Messrs.
Augustine by chlorination and of Mr. Ziervogel by sulphating and mixing with
water. Up to that time only small quantities of silver had been extracted from
copper by the antiquated and costly process of liquation with lead, referred to
earlier in this article. The business of extracting silver soon became very
important, as large quantities of argentiferous regulus were imported from the
west coast of South America, because of the ready market open to them by these
new facilities at the Hafod works. For this purpose another German, B. G.
Herrmann, was engaged from Freiberg. Subsequently, however, the method of
electrodeposition largely superseded the processes which were introduced in
1845, but mention of these in some detail is made later. The extraction of gold
from copper was first commenced in 1850 by the methods invented by Professor
Plattner of Freiberg, who incidentally was the man who introduced blowpipe assay
methods into analytical chemistry.
Fig.
12. Old Forest copper works . (Figures not included for copyright reasons)
By
this time Swansea had become responsible for smelting about a quarter of the
copper ores of the world, and owing to the high sulphur content of such ores the
surrounding town and countryside were continually subjected to a sulphurous
fume, which was known as "copper smoke," and was so heavily laden with
sulphurous and sulphuric acid that all vegetation on the White Rock and Kilvay
Hills was completely burnt up. These gaseous products together with the zinc
oxide fume from the distillation furnaces yielded a copious white fume which
pervaded the whole district. Frequent attempts were consequently made at the
Hafod works by J. H. Vivian and his successors to ameliorate this pollution of
the atmosphere. At various times he was assisted by his friend, Sir Humphry
Davy, and Michael Faraday. These initial experiments were begun in 1812 and
extended at that time over some ten years, but no practical success was achieved
in avoiding the evolution of sulphurous acid gases from the open reverberatory
furnaces. One interesting sidelight from this personal association was that
branches of the Royal Institution in London were formed in Swansea and also at
Truro in Cornwall. Although these branches do not operate as such today, the
society remains and the buildings are still intact and used as a library and
museum. No effort was wanting, no expense spared; but alas, success was not to
crown their efforts, as may be gathered from the following doggerel, which
was applicable not only to
the Hafod, but also to the
neighbouring copper works:
"It
came to pass, in days of yore,
The
devil chanced upon Landore.
Quoth
he-'By all this fume and stink,
I
can't be far from home, I think.' "
This problem was
obviously ever present in the minds of the management at Vivians', and in 1864 a
further attempt was made to contain these gases and Mr. Gestenhoefer invented a
novel type of furnace for roasting the sulphide material. In this the crushed
ore and regulus fell through a vertical furnace, the heat being maintained by
the self-combustion of the ore, no more air being admitted to the furnace than
was necessary to ensure such combustion. This enabled the gases to be
controlled, and sulphuric acid chambers were erected and the process eventually
applied to all suitable sulphides. It was found, however, that some of the ores
or sulphides could not generate sufficient heat to maintain combustion, because
they were either too poor in sulphide or too fusible, and consequently this
method was only suitable for about half of the roasting operations at the Hafod
works.
Fig. 13.
Location of copper smelters, 1771
Fig. 14.
Location of copper smelters, 1822 .
(Figures not included for copyright reasons)
Fig.
15. Location of copper smelters, 1875
The
problem then arose of disposing and utilising the sulphuric acid thus obtained.
One method was to take the copper scale and other copper scrap and manufacture
copper sulphate, which was used as a liquid spray to inhibit diseases of the
vine and other plants. A subsequent outlet for sulphuric acid was found in the
treating of phosphate rock to make superphosphate, which was a valuable
fertiliser. Large quantities of this were made until quite recent times and
shipped to various parts of South Wales and Ireland. Further ramifications of
the Vivian concern which were developed in the last quarter of the nineteenth
century consisted of the purchase of coal mines to ensure the adequate supply of
coal for the smelting of copper ores and also the purchase of additional works
to extract silver and lead from complex silver-lead ores.
In the 1850's
adjacent to the Hafod works of Vivians' was the Morfa works of Williams, which
at that time was the largest in the world. They employed some 620 workers with
120 furnaces for copper and zinc. In this area of South Wales it has been
estimated that some 600 furnaces existed, employing 4000 people. An indication
of the spread and location of many of these works is given in Figs. 13-15. By
this period Bristol had ceased to be an important smelting centre for copper or
zinc, and only small works continued at St. Helens, Amlwch and in north
Staffordshire.
With the
development of chemistry into a science the analysis and smelting of copper ores
through the nineteenth century slowly became more and more objective and
efficient. A flowsheet of the fundamentals of the method about that time is
given in Fig. 16.
In 1856 Percy's
Metallurgy' was published, which gives a very good account of the state of the
art in those days.
The copper ores
which were received in the various docks in Swansea were sold by auction, a
process which had long been known as ticketing. The essence of this was to
unload the ores and for the various chemists associated with the different works
to carry out their own sampling and analysis. Upon the outcome of their findings
bids were made for the parcels of ore on a certain day, and the highest bidder
usually took the lot. A summary of such ticketings is given in Fig. 17. The
practice had begun in Cornwall about 1728, following some glaring examples of
sharp dealing. The four companies of that time had increased to six by 1750 and
thirteen by 1778, so that there were numerous bidders at the dinners which were
held for the purpose at monthly or fortnightly intervals. The ticketings
continued in Cornwall, and in Swansea later, through the nineteenth century. By
1839 the value of the ores being purchased by the Welsh smelters was nearly £l½
million for the year according to the records of W. H. Christoe &
Sons, Truro, who were agents there. The first sale of copper ores in Swansea
occurred in 1804, and as a result of the arrangement of this market in copper
ores Swansea did for a period determine the world price of these ores. The ores
were usually then transferred to barges and sailed up the river Tawe for
unloading at the various private wharves of the smelters. When the ores were
transferred to the various works the rocks were spalled into pieces by
hammering, and sorted by girls who carefully separated the ore from the gangue.
At Hafod an elaborate rail track system was used to transfer the ores to the
appropriate furnaces. The coking and non-coking coals which were available in
the Swansea valley were mixed in the proportion of one part of coking to two
parts of free-burning. The furnaces in use then consisted in essence of
reverbatory types but of differing fire grate to working hearth ratios. Thus the
calciner was a reverbatory furnace taking 7 tons of ore at a time with a curtain
arch which permitted the entry of air for calcination and a fire grate to hearth
area ratio of 1 : 11. On the other hand, the melting furnaces for the regulus
had a bigger grate to hearth area ratio of the order of 1 : 4 and also a 20 in.
bed of sand on which the matte was worked. The detailed operations in 1848
consisted of the following stages:
- Calcination was carried out in the
calcining furnaces referred to, and was virtually a roasting operation.
About 3-4 tons of ore was charged and heated for 12-24 hours, care being
taken to avoid clotting or sintering the mass, and on completion of the
process the material was granulated by quenching in water. By this operation
an ore containing initially 12% copper, 30 iron, 31 Y. sulphur and 24%
silica was reduced in sulphur content to 16%, the total amount of the other
constituents remaining the same.
- Calcined ore was then transferred to
another furnace and melted with metal slag obtained from the fourth
operation, to give a regulus or coarse metal. This contained approximately
35% copper together with approximately 35 % iron and 30 % sulphur. There was
also a certain amount of ore furnace slag produced as a residue, which was
usually dumped on a slag bank, since it contained only 0.4-0-5% residual
copper.
- A further calcination of the regulus
from operation 2 was carried out with free access of air for a period of 24
hours, in the course of which a further considerable quantity of sulphur was
evolved and the copper and iron content increased slightly by 1-2%, the
sulphur being reduced from about 30 % to 15 % and the oxygen content being
raised to about 1 1 %.
- This partially oxidised coarse metal
was remelted with further additions of oxide in the form of copper oxides,
residues and carbonate ores and produced a blue matte or white metal
containing 75 % copper and 21 % sulphur, and was essentially a copper
sulphide. The oxygen which was originally present in the charge was used to
eliminate iron sulphide in the slag. The slag obtained from this operation
analysed approximately 34% silica, 56 ferrous oxide and 5-7 % mixed oxides.
The white metal from this operation was cast into the form of pigs.
- The regulus pigs were charged into a
melting furnace and very slowly heated with free access of oxygen so that
the operation of melting took 6-8 hours. This operation resulted in the
formation of blister copper, which analysed 98-4% copper, 0-7% iron, 0-3%
nickel, cobalt and manganese, 0-4% tin and arsenic and 0.2% sulphur. The
slag produced was essentially siliceous containing various metallic oxides,
the approximate analysis being 47-5y, silica, 17% cupric oxide, 2 % copper,
28% ferrous oxide and 3 % alumina. This slag was then recycled to the metal
furnace for operation 3.
- The final operation was refining
alone, resulting in a marketable copper and a refinery slag which also was
returned to operation 3. In these refinery furnaces 6-8 tons of blister
copper were melted and exposed for 15 hours to oxidation, the slag was
skimmed and dry copper made. At this stage the copper contained
approximately 9 % of cuprous oxide, and the treatment had resulted in the
elimination of most of the impurities such as tin, iron, etc. The charge was
then covered with anthracite or free-burning coal, and a thick birch or oak
pole-the greener the better-was placed under the surface of the molten
metal. The poling operation, as it was termed, resulted in the evolution of
considerable steam and free hydrogen, which eliminated the bulk of the
oxygen from the molten metal. The satisfactory completion of these two
operations of oxidation with air and reduction by poling was judged by the
appearance of the surface "set" of small button samples which were
cast in chill iron moulds. A further test of malleability and ductility was
given by hammering the button flat into a small pancake shape and bending to
fracture across a diameter.
In essence the
formation of a depression in the surface of the sample or "sink"
indicated under-poling, i.e. excess oxygen, while the formation of a ridge or
"spewing" indicated the presence of too much gas, chiefly hydrogen,
which was known as over-poled. A satisfactory copper having good malleability
usually had a flat, wrinkled surface top, could be bent double after hammering
and had a silky fracture. Copper in this condition was known as tough pitch. As
soon as this state of affairs had been achieved in the bath the metal was
quickly ladled by hand, 30lb at a time, into suitable moulds for solidification
as cake, billet or strip. Alternatively, if it was required for brass
manufacture it was granulated in water to give feathered shot which was used by
the makers of calamine brass. For this latter operation, apparently over-poled
copper was preferred. This is understandable in that it yielded copper having a
much greater surface area when granulated; also, since the oxygen content was
low, it resulted in less loss of zinc and copper by oxidation.
Fig. 18. Vivians'
Hafod Works, 1900 .
(Figures not included for copyright reasons)
Brass
manufacturers, in addition to demanding this type of product for the manufacture
of calamine brass, also required the purest type of copper for the manufacture
of brass by alloying. Whereas in the earlier years the Cornish ores solely were
used and yielded a fairly pure type of copper, in the nineteenth century ores
from all over the world introduced various impurities which made the working of
brass for certain purposes difficult. In order to obtain the high quality of
copper, therefore, the refiners had to indulge in various techniques for
selecting the best refining type of copper, and if a satisfactory purity was not
obtained on the first refining operation much of the metal was returned to the
furnace for an additional oxidation and reduction by poling. It is interesting
to note that at this time arsenic was rarely, if ever, completely eliminated,
and considerable amounts are discernible in much of the copper manufactured
during this period. It is also interesting to note that locomotive copper
firebox plates gave good service with this adventitious presence of arsenic, and
in subsequent years, when much purer copper was available, an intentional
addition of arsenic was found necessary to ensure an adequate service life where
hot toughness and scale resistance were required. Of the other major impurities,
antimony could be eliminated by the selection procedure; tin spread into the
bottom half of the charge; while nickel and cobalt remained associated with the
copper.
Various proposals
were made to reduce the number of operations, but no outstanding progress was
made until the discovery of more effective methods of concentrating the ores,
the use of large reverbatory furnaces, and the blowing of air through copper
matte in Bessemer converters radically altered the fundamentals of the Welsh
process.
Following this
period in the development of copper smelting, a small works which it was
estimated had outputs of 1,100 tons per annum of fine copper run on 10% copper
ores could operate satisfactorily with six calcining furnaces and twelve melting
furnaces at a cost of £10,000 and a working capital of £35,000. It was
reliably estimated that 1 ton of copper could be obtained from 18 tons of coal
used, but it was also observed in those days that it is one thing to know how to
make iron and copper and it is another to know how to sell metals.
Fig.
19. Hafod and Upper Bank zinc smelter, 1921
(Figures not included for copyright reasons)
By 1900 many of
the small copper smelting firms had closed down and passed out of existence but
the well-established ones continued, and Figs. 18 and 19 show Vivians' in 1900
and in 1921 respectively. 1n the latter photograph the foreground shows the zinc
smelter still in operation, while on top of the slag dump across the river can
be seen the disused chambers of the sulphuric acid made from the Gestenhoefer
furnaces. Fig. 20 shows the remains of the White Rock works, which had been
largely engaged in extracting precious metals from the slimes remaining after
electrolytic purification of copper and of other precious metal residues. The
ruins of the original Middle Bank smelting works are shown in Fig. 21.
Fig. 20. Ruins of
White Rock Works, 1952 (Figures not included for copyright reasons)
It may be of some
interest to record at this stage the maritime aspect of this industry which had
for so long been based on the port of Swansea.
In the last half of the century the ships
engaged in carrying ore consisted of sailing vessels which were gradually
superseded by steam ships. The foreign ores were in the early days brought in
principally from Cuba, Venezuela, Spain, Portugal and other parts of the
Atlantic seaboard, in sailing ships which were collectively known as
"Copper Ore Men."
Fig. 21. Ruins of
original Middle Bank smelting works, 1952
(Figures not included for copyright reasons)
Later the
Chilean, Bolivian and Peruvian mines were developed, and this meant that ships
carried the ore round the Horn on homeward passage, hence the term "Cape
Horners." The vessels were
barques or ships of approximately 800 tons with a variation either way of about
100 tons. The outward cargoes would consist of coal and stores for the mines and
the homeward cargoes of ores and latterly from Chile of copper metal. These
vessels were locally owned, principally by Baths and Richardsons; those owned by
Baths were named according to the Greek alphabet, Alpha, Beta, Kappa, etc.
The steamers
gradually superseded the sailing vessels, and were in operation long before
1900. They gradually developed into regular traders operating under the Pacific
Steam Navigation Company, the Lampert, Holt and Nautilus lines. These traders
were of the order of 3000-4000 tons, and they would bring in part cargoes of ore
of say 1500 tons and then proceed to Liverpool with the balance of general
cargo. These vessels did not round the Horn but came through the Magellan
Straits and usually made the passage from Chile to Swansea in about six weeks.
Later, of course, with the opening of the Panama Canal this long trip was
avoided.
Although these
vessels constituted the main source of supply of ores, there was in addition a
considerable coastal trade with much smaller vessels of the order of 200-250
tons. These were able to proceed upriver on the spring tides and unload direct
at the wharves of the various smelting works. These small steamers, schooners
and barges brought refractories from Flintshire, with Laxey blende for the
spelter works, pyrites and burnt ore, and ores from Cornwall, Anglesey and
Ireland.
To illustrate the
wide ramifications of the copper ore trade even as recently as A.D. 1900, a list
is given below of some typical cargoes of ores and copper bars and cake.