After successful trials last year into the potential to grow crops that can be used as feedstock for biofuels on mine tailings areas, scientists at Canada’s Mining Innovation, Rehabilitation and Applied Research Corporation will widen the scope this year to include other crop types, as the South African “Mining Weekly” reports.
The aim of the project, which is being undertaken in partnership with Natural Resources Canada, is to use waste organic materials from sources like the pulp and paper industries to form a cover – around one metre thick – over the tailings, creating areas that can be used for agricultural purposes.
If the growth of crops for biofuels can be successfully implemented, the initiative will lead to new jobs, in both the agricultural and biofuels industries, and mining companies would have the benefit of reclaimed tailings areas, Mirarco research scientist Alan Lock told Mining Weekly Online. “Also, mining industries will have the opportunity to gain carbon credits through the growth of biomass on their tailings impound areas.”
In 2008, corn and canola seeds were planted in Canada on tailings at Goldcorp’s Porcupine mine, in Timmins, Vale Inco’s Copper Cliff operation, in Sudbury, and at an agricultural control site in Azilda, north-west of Sudbury. The trials were a “great success”, Lock reported. The results from the year-end fresh biomass sampling revealed that the yield was similar or even greater at the mine sites than at the agricultural control site. Vegetation, soil and ground water samples are still being analysed to determine the potential impacts that the project may have on the remobilisation of metals from the tailings, but so far it seems that metals are not being remobilised into ground water or plant tissues.
This year, the scientists plan to increase the number of crop types, test new cover materials, and will also plant crops at one more area. The plan is to test corn, canola, switch grass and miscanthus in 2009. “We will be adding a second plot at Vale Inco using a different pulp and paper residual and at Xstrata Nickel we will be using a municipal compost,” Lock added.
Source: Mining Weekly, 2009-02-13.