WHAT IS COPPER?
Copper is a base metal in the non-ferrous family of metals. It is known for its red-orange hue that gradually turns gray-green as it is exposed to oxygen. It is considered a soft metal.
Copper is what is known as a native metal: it occurs in nature in a directly usable form, appearing as “nuggets” buried in the ground. However, there is very little native copper in the world; most commercial copper is derived from ores, or metal-rich rocks and minerals. If you’re in the Great Lakes area, you might be lucky enough to stumble across a nugget out in the wild, but in that form, it’s better as a souvenir than as scrap.
Copper gets its name from the Latin cuprum which in turn comes from the Greek aes cyprium, or “metal of Cyprus.” Cyprus is a Mediterranean island where copper was principally mined in the Roman era.
WHERE DOES COPPER COME FROM? HOW IS IT MADE?
The three main ores that copper comes from are chalcopyrite, bornite, and malachite.
Most often, copper ore is mined in open-pit mines. The largest copper mine in the world is in Bingham Canyon in Utah. However, the U.S. is only the second largest producer of copper globally, following Chile. Peru is also a major producer of commercial copper.
Once the ore is mined, it is put through a series of processes that extract and refine the copper within. Fresh, bare copper has a pinkish-orange color.
Because the volume of readily available copper on Earth is limited, recycling is a major source of copper for commercial and manufacturing purposes.
HOW LONG HAVE PEOPLE BEEN USING COPPER?
You might be surprised to know that human use of copper dates back at least 10,000 years. Native Americans in the Great Lakes areas took advantage of locally occurring native copper to make tools. However, the vast majority of the copper ever mined has been extracted in the 20th and 21st centuries.
Copper was the first metal to be smelted from sulfide ores, the first metal to be cast into a mold to produce a specific shape, and the first metal to be blended with another metal, tin, to create the alloy bronze. All of this took place between 5000-3500 B.C.E.
WHAT IS COPPER USED IN?
Copper has a number of uses thanks to its softness and how well it conducts heat and electricity. Some of the most common applications include building materials, jewelry, wire and electrical components, plumbing, cookware, and coins.
Copper is also an important ingredient in alloys, or blended metals. Copper is used to make sterling silver, bronze, and brass, among other alloys.
WHY DOES COPPER TURN GREEN?
Copper is known for being slow to corrode. However, exposure to the elements will take its toll eventually.
Copper turns blue-green for the same reason that weathered iron turns red-orange. The color change is a result of the chemical process of oxidation. The surface of the metal reacts to sulfur and oxide compounds found in the air and water. Copper sulfate lends a blue color, while copper chloride produces a shade of green, and is more likely to be found where salt water is present.
This layer of corrosion is called a patina and can actually be a desirable effect among artists. The iconic color of the Statue of Liberty comes from the patina on the copper that plates her!
Why is copper so valuable?
Copper is the world’s third most used metal because of its versatility and conductivity. Demand for copper tends to track with activity in the housing market, specifically construction of new homes, which need a lot of copper wire and piping. Copper pricing was particularly vulnerable during the 2008 recession, when new home building was at a historic low. Copper prices have recovered since the recession, if not completely back to peak levels.
There are many, many other factors that impact the price of copper, including global investment activity, the health of the global economy, innovations in copper extraction technology, and even seasons and the weather. However, in general, quality copper still commands a strong price as scrap. It’s always a good idea to call ahead when you plan to bring in scrap to find out the most current prices.
Can SOLDER REDUCE THE VALUE OF COPPER?
Any time more than one metal is present on a given product, that tends to diminish the scrap value of the piece. Solder is one common example of a contaminant that can cause your copper to be graded at a lower quality, and therefore a lower price. Solder is an alloy that is generally made with tin or lead. To get the most value for your copper wire and pipes, cut off any pieces that have been soldered before bringing it in.
Why should i recycle copper?
Recycling copper uses about 10% of the energy required to extract new copper. Conserving energy is good news both for our fuel consumption and our CO2 emissions. Mining and extracting new copper is also more expensive than recycling, so recycling helps keep the cost of copper products down. Close to 50% of copper production in the U.S. comes from recycled material.
Copper, like other metals, breaks down so slowly that you might as well say it doesn’t break down at all. That means any copper that ends up in a landfill is there to stay.