Vale swings back into the black on soaring iron ore prices
The world's No.1 iron-ore producer recorded a net profit of $3.98 billion in 2016, a significant recovery from a loss of $12.13 billion it reported a year earlier.
A waste treatment plant that can produce about 500 tons of fertilizer per year, and can generate about 580,000 kWh per year of electricity from the biogas produced from the process.