How Much is Brass and How is it Made?(铜 Peter)

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Brass is a metal alloy made up primarily of copper and zinc. The proportions of copper and zinc can vary to create different types of brass with properties suited for specific applications. Brass is highly malleable and durable, corrosion resistant, and has attractive gold-like colors which make it popular for decorative uses. But how much does brass cost and how is this versatile metal alloy produced?
What is Brass?
Brass is composed mainly of copper, with zinc making up between 5% to 45% of its content. The ratio of copper to zinc determines the properties and classification of the brass alloy. Common types of brass include:
- Yellow brass - 30% zinc, with a bright golden color. The most common and inexpensive type of brass. Used for plumbing fittings, gears, bearings, and bullet casings.
- Red brass - 15% zinc, reddish hue. More ductile than yellow brass. Used for pipes and plumbing fixtures.
- Admiralty brass - 30% zinc, 1% tin. Resistance to saltwater corrosion makes it ideal for marine applications.
- White brass - 50% zinc, more pale yellow color. Used when a silver appearance is desired.
- Green brass - 1% tin, 1% zinc, dark patina finish. Used for architectural purposes.
The malleability, corrosion resistance, attractive appearance and acoustic properties of brass make it popular for musical instruments, decorative door handles and railings, ammunition, valves, and marine applications. The automotive industry is also a major consumer of brass.
What Controls the Cost of Brass?
There are several factors that impact the price of brass:
- Base metal prices - Since copper makes up the majority of brass, copper prices are the primary driver of brass costs. Copper futures are traded on metal exchanges like the London Metal Exchange and Shanghai Futures Exchange.
- Demand - Construction, consumer goods, and the automotive industry all influence demand for brass. More demand means higher prices.
- Energy costs - Smelting and manufacturing brass is energy intensive, so energy prices also affect brass costs.
- Alloy mix - Varying the proportions of metals changes material properties but also changes the price. More copper content makes brass costlier.
- Form - Brass costs vary based on form as ingots, sheets, tubes or rods. Fabrication and processing increases costs.
- Quantity - Brass bought in bulk is cheaper per pound than small quantities.
- Quality - Commercial or architectural grade brass is more expensive than low grade alloys.
To give an idea of price, as of 2023 a pound of yellow brass alloy costs approximately $3 to $4. High quality architectural bronze (90% copper) can cost $8 per pound or more.
Brass Production Process
Brass is produced using a combination of mining, smelting, alloying, and fabricating processes:
1. Mining copper and zinc ores - Natural copper and zinc minerals are mined from the earth via processes like underground mining, open pit mining or solution mining. Ores are obtained containing relatively small concentrations of the desired metals.
2. Concentrating the ores - Froth flotation and other enrichment processes are used to increase the metal contents of the mined ores. This concentrates the material to be smelted.
3. Smelting the ore - Smelting uses heat and chemical reducing agents to liberate pure copper and zinc from their ores. This produces a copper concentrate and a zinc concentrate.
4. Alloying - The copper and zinc concentrates are alloyed together in the desired proportions, along with any other metals like tin or lead. They are melted together at about 900°C to combine the metals into brass.
5. Casting the brass - Molten brass can be poured into molds to produce ingots, sheets or continuous cast rods. Common casting methods are continuous casting and hot extrusion.
6. Fabricating the alloy - Cast brass is then machined and fabricated into its final shapes and forms. Techniques like rolling, forging, stamping, and drawing stretch and shape the metal into pipes, tubes, fittings, and more.
7. Finishing - The final surface is polished, buffed, lacquered, or plated to achieve the desired appearance and corrosion resistance.
Brass emerges from this process as the flexible, bright yellow metal available for all types of applications and decorative uses. While intricate to produce, brass still remains an affordable metal thanks to its widespread availability and ease of alloying. Understanding the details of its production also sheds light on the factors that influence the cost of this useful copper alloy. CNC Milling