Of all the minerals, gold is probably the more useful thanks to its diversity of special properties. Gold conducts electricity very well, it does not tarnish, it melts at low temperatures making it very easy to work, it can be drawn into wire, it can be hammered into thin sheets and it alloys with many other metals.
Gold is used in jewellery for its wonderful colour and brilliant lustre, but it can be found also in many products that we use in our everyday life. Laptops, phones, cameras and many other devices use gold to connect components.
When thinking about conductors, most people picture copper, probably because it’s the metal that is commonly used. Silver is actually the best conductor, followed by gold. Silver, however, tarnishes quickly when in contact with air. Copper is cheaper than precious metals, but it’s also much slower in transporting electrons. In the world of computing and communications, speed is more important than cost, so the use of gold has become a standard.
The beneficial material properties of gold include outstanding resistance to corrosion, the ease with which it can be worked and high thermal and electrical conductivity. In conditions under which most other metals either tarnish or corrode away, gold remains inert and extremely durable.
For electronic applications, the resistance of gold to environmental effects is perhaps its most important property as it assures that the technical performance of gold wires or gold electroplating remain essentially unaltered with time.
In general, the more sophisticated the equipment and the greater the need for reliability, the greater is the requirement to exploit the advantages of gold as a material. This means that in telecommunications, computers, automotive electronics and defence systems where safety is critical, gold is indispensable. The importance of high quality and reliable performance justifies the high cost.
Gold’s many qualities make it the metal of choice for a wide variety of industries.
Electronic components made with gold are highly reliable. Gold is used in connectors, switch and relay contacts, soldered joints, connecting wires and connection strips.
Edge connectors used to mount microprocessor and memory chips onto the motherboard and the plug-and-socket connectors used to attach cables all contain gold. The gold in these components is generally electroplated onto other metals and alloyed with small amounts of nickel or cobalt to increase durability.
In phones, most of the gold is in the SIM card, the main board and the smaller components on the back of the LCD screen.
Gold is being used for fillings, crowns, bridges and orthodontic appliances. Gold is a bio-compatible metal, meaning it can be placed in contact with a person’s body and not cause harm to one’s health. It was much more generously used in dentistry up until the late 1970s. The sharp run-up of gold prices at that time motivated the development of substitute materials. However, the amount of gold used in dentistry is starting to rise again. Some motivation for this comes from concerns that less inert metals might have an adverse effect on long-term health.
Many parts of every space vehicle are fitted with gold-coated polyester film. This film reflects infrared radiation and helps stabilize the temperature of the spacecraft. Without this coating, dark coloured parts of the spacecraft would absorb significant amounts of heat.
Gold is also used as a lubricant between mechanical parts. In the vacuum of space, organic lubricants would volatilize and they would be broken down by the intense radiation beyond Earth’s atmosphere. Gold has a very low shear strength, and a thin film of gold between critical moving parts serves as a lubricant – the gold molecules slip past one another under the forces of friction and that provides a lubricant action.
The visor on the helmet of an astronaut’s space suit is coated with a very thin film of gold. This thin film reflects much of the very intense solar radiation of space, protecting the astronaut’s eyes and skin.
Gold has many uses in the production of glass. The most basic use in glassmaking is that of a pigment. A small amount of gold, if suspended in the glass when it is annealed, will produce a rich ruby colour.
Gold is also used when making specialty glass for climate-controlled buildings and cases. A small amount of gold dispersed within the glass or coated onto the glass surface will reflect solar radiation outward, helping the buildings stay cool in the summer, and reflect internal heat inward, helping them stay warm in winter.
How to refine gold from scraps
So just how much precious metal do you have gathering dust, and more importantly, what’s the best way to take advantage of the possible gold mine at your fingertips?
Electronic products are one of the bigger users of gold. There’s a lot of obsolete electronics out there with TVs, computers, phones having lives of 5 years or less.
The key is to remember that with the mass proliferation of electronic devices also comes the massive build-up of electronic waste. It’s e-waste that can easily end up as a huge burden on the environment if each unit is not discarded properly. At the moment, more than 80 per cent of e-waste ends up in landfills, making it a pretty serious environmental issue.
In addition to this, most of the times, the gold is bound up with a lot of other hazardous chemicals so it’s always a good idea to ask a professional precious metal refiner for help.
The key ingredient to maximizing the obvious potential of electronic waste is proper recycling and extraction. According to the American Environmental Protection Agency, «Experts estimate that recycling 1 million cell phones can recover about 24 kg (50 lb) of gold, 250 kg (550 lb) of silver, 9 kg (20 lb) of palladium, and more than 9,000 kg (20,000lb) of copper.»
Many businesses don’t realise that they can be leveraging scrap gold to their advantage, and all they need is a specialist precious metal refiner to take care of this on their behalf, and ensure that they are getting the best possible price for their precious materials.
It is important for manufacturers to be aware of procedures in their processes which may generate precious metal scrap suitable for recycling.