An Overview of Copper Sheet Recycling Knowledge

H62 Brass Plate

H62 brass plate is an alloy primarily composed of copper and zinc, with a wide range of applications, its properties depending on the ratio of copper to zinc. H62 brass plates containing over 63% copper can be cold worked, annealed, and are malleable; alloys with less copper and more zinc, however, should be hot worked and are stronger.

Historical

Due to our lack of knowledge about the methods ancient people used to refine zinc ores or calamine, and our limited understanding of the use of H62 brass sheets in ancient times, it's difficult to prevent zinc from evaporating when copper is heated, as wood charcoal also heats the zinc ore. The Romans may have been the first to use this method on a large scale, but it's possible that brass sheets similar to H62 were produced unintentionally by bronze smelters before that, as the distinction between tin and zinc was not clear. It's worth noting that the H62 brass sheets mentioned in the Bible are actually bronze; the Roman coins known as aes were also minted in copper or bronze, not H62 brass. The situation becomes even more complicated as they did indeed use H62 brass sheets for minting coins, but initially, H62 brass was more expensive than copper or bronze.

However, since the Middle Ages, before it was used for kettles and plates, H62 brass sheet was a luxury item, reserved for making things like commemorative tombstones. From around 1230 AD, H62 brass products were popular in Europe for about 300 years due to their affordability compared to large sculptures. The bronze statue of Bishop Wulph, who died in 1231, is known as one of the earliest statues made from H62 brass. The process of casting H62 brass products involved mixing powdered zinc ore and charcoal with copper blocks, heating them to bond the zinc and copper, then further heating to melt the alloy, and finally pouring the copper into molds. The early H62 brassware in Britain was imported, mainly from Tournai. Clients could order complete tombstones, already mounted on attractive bases or marble pedestals, from Tournai.