With natural deposits of metal on the decline, new ways to improve metal refinement and recycling have emerged. A team of chemists in Canada thought of and developed a method which is consuming less energy and is having a less harmful impact on the environment. It is a step closer to a ‘green’ future.
Science Advances published a paper which revealed the outline of the experiments: organic molecules were used instead of toxic chlorine and hydrochloric acid to help purify germanium, a semiconductor used in infrared optics, solar cell applications, LEDs, and nano-wires. Germanium seldom appears in high concentrations and is often found in combination with zinc. The same technique also proved to be working on other metals such as zinc, copper, manganese and cobalt.
To reduce the unwanted waste, it is necessary to take the perspective from a new angle. The researchers were inspired by melanin, a group of natural pigments found in most organisms, which also has the ability to bind to metals. They are currently trying to synthesize a molecule with similar properties, keeping in mind the possibility of extracting germanium at room temperature, without the help of solvents.
Another technique has found a place in mechanic-chemistry: stainless-steel balls in jars are shaken at high speeds to purify the metal. This method is solvent-free and requires no heat – it relies on mechanical force.
It is believed that further development of the technology will lead to its use on the industrial scale, for a variety of metals.