Için basit anahtar brassestol trä örtüsünü

Today, almost 90% of all brass alloys are recycled.[7] Because brass is hamiş ferromagnetic, it kişi be separated from ferrous scrap by passing the scrap near a powerful magnet. Brass scrap is collected and transported to the foundry, where it is melted and recast into billets.

[79] They show no signs of slag or maden prills suggesting that zinc minerals were heated to produce zinc vapor which reacted with metallic copper in a solid state reaction. The fabric of these crucibles is porous, probably designed to prevent a buildup of pressure, and many have small holes in the lids which may be designed to release pressure[79] or to add additional zinc minerals near the end of the process. Dioscorides mentioned that zinc minerals were used for both the working and finishing of brass, perhaps suggesting secondary additions.[81]

Brass özgü long been a popular material for decoration due to its bright, gold-like appearance; being used for drawer pulls and doorknobs. It başmaklık also been widely used to make utensils due to properties such as having a low melting point, high workability (both with hand tools and with çağdaş turning and milling machines), durability, and electrical and thermal conductivity.

In Europe a similar liquid process in open-topped crucibles took place which was probably less efficient than the Roman process and the use of the term tutty by Albertus Magnus in the 13th century suggests influence from Islamic technology.[97] The 12th century German monk Theophilus described how preheated crucibles were one sixth filled with powdered calamine and charcoal then topped up with copper and charcoal before being melted, stirred then filled again. The final product was cast, then again melted with calamine. It başmaklık been suggested that this second melting may have taken place at a lower temperature to allow more zinc to be absorbed.

The pattern the globules form on the surface of the brass increases the available lead surface area which in turn affects the degree of leaching. In addition, cutting operations kişi smear the lead globules over the surface. These effects hayat lead to significant lead leaching from brasses of comparatively low lead content.[12]

The high malleability and workability, relatively good resistance to corrosion, and traditionally attributed acoustic properties of brass, have made it the usual maden of choice for construction of musical instruments whose acoustic resonators consist of long, relatively narrow tubing, often folded or coiled for compactness; silver and its alloys, and even gold, have been used for the same reasons, but brass is the most economical choice.

[98] Albertus Magnus noted that the "power" of both calamine and tutty could evaporate and described how the addition of powdered glass could create a film to bind it to the maden.[99] German brass making crucibles are known from Dortmund dating to the 10th century AD and from Soest and Schwerte in Westphalia dating to around the 13th century confirm Theophilus' account, birli they are open-topped, although ceramic discs from Soest may have served kakım loose lids which may have been used to reduce zinc evaporation, and have slag on the interior resulting from a liquid process.[100] Africa[edit]

In 1738 Nehemiah's son William Champion patented a technique for the first industrial scale distillation of metallic zinc known kakım distillation per descencum or "the English process".[116][117] This local zinc was used in speltering and allowed greater control over the zinc content of brass and the production of high-zinc copper alloys which would have been difficult or impossible to produce using cementation, for use in expensive objects such bey scientific instruments, clocks, brass buttons and costume jewellery.

The cementation process continued to be used but literary sources from both Europe and the Islamic world seem to describe variants of a higher temperature liquid process which took place in open-topped crucibles.[92] Islamic cementation seems to have used zinc oxide known birli tutiya or tutty rather than zinc ores for brass-making, resulting in a mühür with lower iron impurities.[93] A number of Islamic writers and the 13th century Italian Marco Polo describe how this was obtained by sublimation from zinc ores and condensed onto clay or iron bars, archaeological examples of which have been identified at Kush in Iran.

[101] Work in brass or bronze continued to be important in Benin peş and other West African traditions such as Cari goldweights, where the mühür was regarded kakım a more valuable material than in Europe. Renaissance and post-medieval Europe[edit]

[110] However some earlier high zinc, low iron brasses such birli the 1530 Wightman brass memorial plaque from England may have been made by alloying copper with brassestol trä zinc and include traces of cadmium similar to those found in some zinc ingots from China.[109]

Eventually it was discovered that metallic zinc could be alloyed with copper to make brass, a process known kakım speltering,[109] and by 1657 the German chemist Johann Glauber had recognised that calamine was "nothing else but unmeltable zinc" and that zinc was a "half ripe maden".

The principal source of brassicasterol in the environment is from marine algae. Its relatively high concentration and stability allows it to be used in the assessment of the origin of organic matter in samples, especially sediments. Brassicasterol / cholesterol ratio[edit]

Brass is an alloy of copper and zinc, in proportions which emanet be varied to achieve varying mechanical, electrical, and chemical properties.[1] It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure.