Johannesburg — If you have a smartphone, laptop, tablet or an electric car, your device is likely making use of the mineral cobalt, which was very likely mined in the Democratic Republic of Congo. Roughly 70% of the world's supply of the vital metal comes from the southern DRC, and with electric vehicles sales soaring, e-technology as popular as ever and no major new source of cobalt on the horizon, that number looks set to keep climbing. Cobalt is built into most lithium-ion batteries in electric devices and vehicles to help prevent them from catching on fire. Along with demand...