Metal recycling includes recovering scrap metal from either end-of-life products or structures or manufacturing scrap so that it can be recycled to produce new goods. It involves the identification, recovery, refinement and reclaiming of precious and non-precious metals.
Why refining and recovering metals is important
We are accustomed to hearing about the three R’s of recycling (reduce, reuse, and recycle) to include paper, plastics, bottles, cans, and cardboard. However, most people do not know that precious and non-precious metals can also be recycled.
Recycling metal reduces pollution, saves resources, prevents waste from going to landfills, and prevents habitat destruction from mining new ore. Scrap metal is a continuous resource. Due to its ability to be melted and reshaped countless times, recycled metal is an inexhaustible resource. New metal production causes far greater greenhouse gas emissions compared to recycling metal. These emissions may contribute to climate change and may also create harmful levels of air pollution in cities which may result in respiratory problems for residents.
In uncertain economic times investors have fallen back to the more stable commodities market, with precious metal prices (Gold and Silver in particular) rocketing as a result. Those precious metals can still be mined from natural sources, but mining is very costly, and in many cases, it is becoming more and more cost-effective for those metals to be recovered from devices that already contain them. Recycled cell phones contain more gold than the gold ore that exists in most mines.
How to identify metals to refine
The difference between ferrous and non-ferrous metals can be determined with a magnet. Ferrous metals contain iron whereas non-ferrous metals do not contain iron. An appearance test is the most common, involving studying the physical characteristics of the metal. This can be quite challenging since many metals look similar to each other. If you look closely enough, however, you will notice that gold is heavier and brass produces a bell-like vibration when struck. Additional tests include the fracture test, which features an examination of a broken part and the spark test, using a grinder to produce a spark.
You can also use some simple rules to identify precious metals such as gold, silver, and platinum.
- A magnet won’t attract a precious metal and you know it is an alloy rather than a precious metal if it attracts the magnet.
- If the gold piece seems to leave a black mark on the tile surface, it doesn’t contain the purest gold. High-quality gold pieces will leave a yellow or gold streak on the tile surface.
- Silver also feels warm to the touch — silver feels closer in temperature to your body when it is in your hand — and it is a great heat conductor.
- Gold rubs off differently from silver. If you rub gold against a cloth, you won’t see any impression. However, silver-plated items will leave a shiny black mark.
Common metals that can be recycle and how to identify them
Aluminium is extremely light — three times lighter than iron. It is also completely non-magnetic, so even the strongest magnets will not affect it. As Aluminium doesn’t rust, it is very durable. Typical uses include: Drink cans, Window frames, Cooking pots, Food packaging, Boats and aircrafts, Overhead power lines.
Copper: If exposed to excess water or oxygen for an extended period of time or excessive handling, copper can turn green or black in areas where it has been excessively handled. Copper is a soft metal, so it can be challenging to keep pieces perfectly smooth when working with copper. Even your bare hands may be able to bend the copper piece if it is thin enough. You may also knock on the piece and hear the sound it makes. Real copper will sound deep and warm, unlike brass, which is tinny and harsh. Typical uses: Wires, Motors, Roofing, Plumbing, Cookware, Rainspouts
Brass: Different proportions of copper and zinc result in various colors, but the most common brass types have a muted yellow color, or a yellow-brown appearance similar to bronze. Brass alloys are widely used in machined parts and screws. The hundreds of different combinations mean the metal cannot be identified in one way. Typically used in: Lamp and plug fittings, Electrical terminals, Locks, Marine engines, Valve guides, Door lock components, Wind instruments, Radiator cores, tubes, and tanks.
– Gold Gold is a shiny yellow color and does not contain oxides. It has a melting point of 1064.18°C (1947.52°F). Typical uses for gold: Jewelery, Coinage, Watches, Electrical connectors, Amputations, Dental implants, Computers, Electronics, and other nonferrous metals.
Lead has a relatively low melting point, 327°C (621°F). Lead is nonferrous and can be carved with a pocket knife and is used as a pencil as well. Typical uses include: Pipes, Flashing, Gutters, Downspouts, Conductor Heads, Ammunition, Cable sheathing, Weights for lifting, Weight belts for diving, Radiation protection.
– Steel Steel is a dense, relatively heavy material that easily rusts, so the surface must be painted, galvanized, cleaned often, encased in concrete, or protected in some other way. Freshly grinded carbon steel looks shiny and metallic; otherwise it has a dull, dark (but still metallic) color. On a grinder, steel produces lots of sparks. As a rule, the greater the spark bursts, the higher the carbon content of the steel. Typical use in: Bars, Rods, Rails, Wires, Pipes, Automotive parts, Appliances, Fittings, Flanges, Valves
– Silver is a soft, ductile, malleable, and lustrous metal with the highest electrical and thermal conductivity among all metals. Silver is stable to oxygen and water but tarnishes when exposed to sulfides. Typical use in: Jewelry, Mirror manufacturing, Dental fillings, Silver nitrate films for photography and radiography, Electrical contacts, Silver-cadmium batteries, Silver-zinc batteries.
At NRI Metals we have years of experience in recycling metals from a number of industry sectors. We can help you turn seemingly insignificant scraps into profit for your company. We are both silver refiners and gold refiners and thanks to our extensive expertise we can ensure we will return the maximum value of your material.