Man peeling off insulation from wire to get copper

August 23, 2018 1 min to read

Methods Used to Separate Copper from Other Metals

Category : Feature

Recycling is the perfect solution for saving manufacturing materials, reducing landfill and conserving environmental resources. Metal recycling accounts for approximately 40% of solid waste recycling. One of the most commonly recycled non-ferrous metals is copper.

Recycled copper is primarily used to manufacture electrical cables and devices, plumbing appliances and other products. There are various methods of separation in copper recycling, thanks to technological advancement. Here are the three commonly used methods:

Electrowinning/Electroextraction

This method involves the use of electricity to extract metal from its dissolved state. The metals to be recycled are first melted into a leach solution. A cathode and anode then pass an electric current through the leach solution, causing a chemical reduction of copper and other non-ferrous metals. The reduction causes the metals to form a layer on the cathode from where they are extracted and separated.

Precipitation

This technique is used to recover copper from aqueous solutions. Precipitation is a two-step process involving co-precipitation and adsorption. Chemicals such as oxides and calcium or sodium hydroxide are added to aqueous solutions containing copper where they increase PH, hence forming insoluble metal hydroxides. The insoluble hydroxide called a copper precipitate is then cleaned and reused to manufacture new products.

Metal Sensors

Metal sensors are used to separate different mixed metals. The sensor can be manual or use gravimetric “sink-float” techniques in which heavy metals are sunk to the bottom of the pile. Recently, X-ray technology has been incorporated into this method to separate different metals according to their atomic density.

After the separation of copper from a metal pile, the copper is melted using various techniques then reused in multiple applications. The recycled copper meets approximately 60% of the demand in today’s manufacturing processes. Selling copper products that you do not use to a recycling plant gives you much cash because copper is among the metals in highest demand nowadays.