Metal recycling saves money and allows manufacturing businesses to reduce their production cost.
Metal recycling is different from other types of recyclable materials because metals can be recycled again and again without altering their properties. And metal is abundantly available because it is more likely to be sold to scrap yards than sent to the landfill. In addition to the household metals you throw into the recycle bin, it can be reclaimed from scrap vehicles, (the largest source of scrap ferrous metal in the U.S.), steel structures, railroad tracks, ships, farm equipment, and consumer scrap (like rain gutters and aluminum cans).
There are two classifications of metal: ferrous, (combinations of iron with carbon), or non-ferrous. Ferrous metals include carbon steel, alloy steel, wrought iron, and cast iron. Non-ferrous metals include aluminum, copper, lead, zinc, and tin. Precious metals are non-ferrous. The most common precious metals include gold, platinum, silver, iridium, and palladium.
When sorting metals from a mixed stream of recyclable material, paper is removed first leaving only plastics and metals. Then, electric currents are induced across the stream where only metals get affected. This process is called Eddy Current Separation. Metals are separated using magnets and sensors. Some types of metal can also be distinguished by material color or weight; copper, yellow brass, and red brass can be spotted by their color; aluminum will be silver and light.
Next, shredding is done to enhance the melting process. Small shredded metals have a large surface to volume ratio so they can be melted using comparatively less energy than whole pieces. Aluminum is converted into small sheets and steel is changed into steel blocks.
Aluminum is collected and taken to a treatment plant where it is sorted and cleaned for reprocessing. A re-melt process turns this into molten aluminum, removing the coatings and inks that may be present. Then it is made into large blocks called ingots. (According to the UK website Recycling Guide, each ingot contains enough metal for about 1.6 million drinks cans.) These are sent to mills where they are rolled out, giving the metal greater flexibility and strength. In as little as six weeks, the aluminum cans you throw into the recycle bin can be made into products such as new cans, chocolate wrapping, food packaging, and then recycled, starting the process over again.
Scrap Metal Recycling
Scrap metal is melted in a large furnace. Each metal is taken to a specific furnace designed to melt that particular metal. A considerable amount of energy is used in this step, yet still much less than the energy needed to produce metals using virgin raw materials.
To ensure the final product is of high quality and free of contaminants, the metal is then purified. After purification, melted metals are cooled and solidified. In this stage, scrap metals are formed into specific shapes, such as bars, that can be easily used for the production of various metal products. These pieces are transported to factories where they are used as raw material for the production of brand new items.
When the products made of these metal bars comes to the end of their useful life, the metal recycling process cycles again.
Metal Recycling Facts
According to The Balance:
- Although almost every kind of metal can be recycled again and again, currently only 30 percent of metal is recycled.
- Nearly 40 percent of worldwide steel production is made using recycled steel.
- Around 42 percent of crude steel in the United States is made of recycled materials. In the U.S., around 100 million steel and tin cans are used every day.
- Steel and iron are the most recycled materials in the world due in part to the opportunity to recover large structures as well as the ease of reprocessing.
- Every year, around 400 million tons of metal is recycled worldwide.
- Currently, the single most recycled consumer product in the U.S. is the aluminum can.
- Throwing away a single aluminum can wastes energy equivalent to that same can filled with gasoline.
Metals are valuable materials that can be recycled again and again without degrading their properties. Scrap metal has monetary value, encouraging people to collect and sell it to recycling operations. In addition to a financial incentive, there is also an environmental benefit. The recycling of metals enables us to preserve natural resources while requiring less energy to process than the manufacture of new products using virgin raw materials. Recycling emits less carbon dioxide and other harmful gasses. More importantly, it saves money and allows manufacturing businesses to reduce their production cost.
Creative Metal Recycling
However, not all metals are recycled through a recycling center. The website, Remove and Replace, has some creative ways consumers have recycled metals.
How about a tuba turned into a water fountain, bicycle pedals and gears stool, or license plate birdhouse for a few ideas? And these timing gear book ends, or refrigerant tanks, coil springs and oil filter yard art from the Welding Web website.