"Indeed, a natural ore mine can produce 5 g of gold (Au) per ton of ore, while 200–250 g Au can be recovered from the same mass of computer boards (300–350 g Au/t for mobile phones) [6]."
"Indeed, a natural ore mine can produce 5 g of gold (Au) per ton of ore, while 200–250 g Au can be recovered from the same mass of computer boards (300–350 g Au/t for mobile phones) [6]."