Calamine brass
Encyclopedia
Calamine brass is brass
produced by a particular alloy
ing technique using the zinc
ore
calamine
directly, rather than first refining it to metallic zinc. Zinc smelting is difficult and the pure metal was largely unknown historically, even though the alloyed calamine brass was in use for centuries.
Brass is an alloy of copper
and zinc
and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists
wishing to produce brass thus used calamine (actually a mixture of the virtually indistinguishable zinc ores smithsonite
and hemimorphite
) as the zinc component of brass. The resulting brasses, produced by heating a mixture of copper and calamine to a high temperature for several hours (allowing zinc vapor
to distill from the ores and permeate the metallic copper), contained a significant amount of slag
material resulting from the non-zinc components of calamine. The use of ore rather than metallic zinc also made it difficult to accurately produce the desired final proportion of copper to zinc. This process is known as cementation
.
Calamine brass was produced using proportions of two-sevenths fine copper
, four-sevenths calamine, and one-seventh shruff (old plate brass). Calamine brass was the first type of brass produced, probably starting during the 1st millennium BC
, and was not replaced in Europe
by other brass manufactures until the 18th century (it is likely that India
n brass manufacturers had developed more advanced techniques some centuries earlier).
The mineral calamine takes its name from La Calamine in Belgium
. That area was the source of much of the medieval brass of northern Europe. Brass production was introduced to England in 1587 when several members of the Company of Mineral and Battery Works
obtained a licence from the company (within whose monopoly it was) to build brass works at Isleworth
. However a decade later the company obstructed the owners from mining calamine.
New brass works were built by Jacob Momma, a German immigrant in 1649 at Esher
, probably using Swedish
copper. After the passing of the Mines Royal Act
in 1689, further works were built near Bristol
, where brass production became a major industry in the 18th century. Later brass production sites in England included Cheadle
and Birmingham
.
Calamine brass was slowly phased out as zinc smelting
techniques were developed in Europe, which produced metallic zinc more suitable for brass production than calamine. However, the conversion away from calamine brass manufacture was slow; a British
patent
was awarded to William Champion
in 1738, but the alloying of metallic zinc and copper to produce brass was not patented until 1781 (by James Emerson), and calamine brass mills persisted in South Wales
until as late as 1858. The slow diffusion of this technology was probably the result of economic factors.
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
produced by a particular alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
ing technique using the zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
calamine
Calamine (mineral)
Calamine is a historic name for an ore of zinc. The name calamine was derived from the Belgian town of Kelmis, whose French name is "La Calamine", which is home to a zinc mine...
directly, rather than first refining it to metallic zinc. Zinc smelting is difficult and the pure metal was largely unknown historically, even though the alloyed calamine brass was in use for centuries.
Brass is an alloy of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists
Metallurgy
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...
wishing to produce brass thus used calamine (actually a mixture of the virtually indistinguishable zinc ores smithsonite
Smithsonite
Smithsonite, or zinc spar, is zinc carbonate , a mineral ore of zinc. Historically, smithsonite was identified with hemimorphite before it was realised that they were two distinct minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some...
and hemimorphite
Hemimorphite
Hemimorphite, is a sorosilicate mineral which has been mined from days of old from the upper parts of zinc and lead ores, chiefly associated with smithsonite. It was often assumed to be the same mineral and both were classed under the same name of calamine...
) as the zinc component of brass. The resulting brasses, produced by heating a mixture of copper and calamine to a high temperature for several hours (allowing zinc vapor
Vapor
A vapor or vapour is a substance in the gas phase at a temperature lower than its critical point....
to distill from the ores and permeate the metallic copper), contained a significant amount of slag
Slag
Slag is a partially vitreous by-product of smelting ore to separate the metal fraction from the unwanted fraction. It can usually be considered to be a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and metal atoms in the elemental form...
material resulting from the non-zinc components of calamine. The use of ore rather than metallic zinc also made it difficult to accurately produce the desired final proportion of copper to zinc. This process is known as cementation
Cementation process
The cementation process is an obsolete technique for making steel by carburization of iron. Unlike modern steelmaking, it increased the amount of carbon in the iron. It was apparently developed before the 17th century. Derwentcote Steel Furnace, built in 1720, is the earliest surviving example...
.
Calamine brass was produced using proportions of two-sevenths fine copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, four-sevenths calamine, and one-seventh shruff (old plate brass). Calamine brass was the first type of brass produced, probably starting during the 1st millennium BC
1st millennium BC
The 1st millennium BC encompasses the Iron Age and sees the rise of many successive empires, and spanned from 1000 BC to 1 BC.The Neo-Assyrian Empire, followed by the Achaemenids. In Greece, Classical Antiquity begins with the colonization of Magna Graecia and peaks with the rise of Hellenism. The...
, and was not replaced in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
by other brass manufactures until the 18th century (it is likely that India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
n brass manufacturers had developed more advanced techniques some centuries earlier).
The mineral calamine takes its name from La Calamine in Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
. That area was the source of much of the medieval brass of northern Europe. Brass production was introduced to England in 1587 when several members of the Company of Mineral and Battery Works
Company of Mineral and Battery Works
The Company of Mineral and Battery Works was, , one of two mining monopolies created by Queen Elizabeth I of England in the mid-1560s. The Company's rights were based on a patent granted to William Humfrey on 17 September 1565. This was replaced on 28 May 1568 by a patent of incorporation, making...
obtained a licence from the company (within whose monopoly it was) to build brass works at Isleworth
Isleworth
Isleworth is a small town of Saxon origin sited within the London Borough of Hounslow in west London, England. It lies immediately east of the town of Hounslow and west of the River Thames and its tributary the River Crane. Isleworth's original area of settlement, alongside the Thames, is known as...
. However a decade later the company obstructed the owners from mining calamine.
New brass works were built by Jacob Momma, a German immigrant in 1649 at Esher
Esher
Esher is a town in the Surrey borough of Elmbridge in South East England near the River Mole. It is a very prosperous part of the Greater London Urban Area, largely suburban in character, and is situated 14.1 miles south west of Charing Cross....
, probably using Swedish
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
copper. After the passing of the Mines Royal Act
Mines Royal Act 1689
The Mines Royal Act 1689 was an act of the Parliament of England with the long title An Act to prevent Disputes and Controversies concerning Royal Mines. The act repealed the 1404 Act Against Multipliers The Mines Royal Act 1689 was an act of the Parliament of England (1 Will. & Mar. sess. 1 c....
in 1689, further works were built near Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
, where brass production became a major industry in the 18th century. Later brass production sites in England included Cheadle
Cheadle, Staffordshire
Cheadle is a small market town near Stoke-on-Trent, Staffordshire, England, with a population of 12,158 according to the 2001 census. It is roughly from the city of Stoke-on-Trent, north of Birmingham and south of Manchester...
and Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
.
Calamine brass was slowly phased out as zinc smelting
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
techniques were developed in Europe, which produced metallic zinc more suitable for brass production than calamine. However, the conversion away from calamine brass manufacture was slow; a British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
was awarded to William Champion
William Champion (metallurgist)
William Champion is credited with patenting a process in Great Britain to distill zinc from calamine using charcoal in a smelter.Champion came from a family who were already concerned in the metal trade at Bristol, his father being a leading partner in the Bristol Brass Company. As a young man he...
in 1738, but the alloying of metallic zinc and copper to produce brass was not patented until 1781 (by James Emerson), and calamine brass mills persisted in South Wales
South Wales
South Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...
until as late as 1858. The slow diffusion of this technology was probably the result of economic factors.