You must pay attention when the news item starts thus: “Using life cycle assessment (LCA) methodology, Australia’s natural science agency CSIRO has established that water used by the mining industry reaps more economic benefit than water consumed by agriculture and industry.”

Dorothy Kosich writes for Mineweb on mining matters. I love her writing and read everything by her I can lay my hands on. I am told that Mineweb is a competitor to InfoMine. So be it. In the world of the web, there are no boundaries so I read what I will and seek as always to collate technical information relevant to mining. Hence I repeat (and edit somewhat for context) a bit more of what she writes in the latest article, but all the while recommend you take a look at the original.

  • The minerals sectors uses very little water during mining, with the majority used in processing and refining--grinding, flotation, gravity concentration, dense medium separation and hydrometallurgical processes all use substantial amounts of water.
  • Water consumption for producing various metals ranged from 3 cubic meters of water per tonne of steel to 250,000 cubic meters per ton of gold, with results largely reflecting the grade of the ore.
  • To process one tonne of refined copper required 13.6 cubic meters of water in the mining and concentrating stage, 7.8 cubic meters during smelting, and 0.6 cubic meters in the refining stage. Norgate said that understanding water usage at each stage can help the mining industry reduce its water consumption.
  • The Australian minerals industry uses about 80% groundwater, 15% surface water, and 5% main infrastructure water with the majority coming from dams, rivers, lakes and groundwater sources.
  • Water recycling is an obvious tool to help reduce water consumption by mining; issues such as organic and inorganic build-up microbial species and flotation collection influence the extent to which this is achieved.
  • Many Australian mining operations already use water that is unfit for agricultural a flexible, fit for purpose water strategy that accounts for local conditions and synergies need to be more broadly adopted by mining, mineral processing and metal production operations.

The Australian study Dorothy is writing about was undertaken using Life-Cycle Assessment (LCA). Here are some links to information about this concept and methodology: