Robert Pelton, Songtao Yang, and colleagues at McMaster University (in Hamilton, Ontario) have devised a means of recovering almost 100% of the mining ores being separated in a process called froth flotation. Here’s a description of the usual froth flotation process (from the Sept. 15, 201 news item in Science Daily),
Robert Pelton and colleagues explain that companies use a technique termed froth flotation to process about 450 million tons of minerals each year. The process involves crushing the minerals into small particles, and then floating the particles in water to separate the commercially valuable particles from the waste rock.
Currently, mining companies add a ‘collector’ particle which attaches to the valuable mineral particles, repels water, and causes the mineral to rise to the surface of the water for easy separation from the rocks.
The team from McMaster has developed a new collector particle, a hydrophobic (water-repelling) nanoparticle which ensures, in laboratory tests, almost 100% ore recovery.
Cameron Chai at Azonano offers a little more detail in his Sept. 17, 2011 article about the new technology. I haven’t seen mention in either article as to what happens to the waste resulting from froth flotation.
Some of the McMaster team’s funding came from Vale, formerly Inco a 100 year old nickel mining Canadian company.