Process Water Recycling

Copper Metal Recovery – Acid Mine Drainage

We selectively recover copper and other valuable metals and minerals from the acid mine drainage (AMD) process using a high purity cathode.

AMD, or acid rock drainage, occurs naturally within some environments as part of the rock weathering process, but is exacerbated by large scale earth disturbances found with copper mining or exhausted heap leach operations.

After being exposed to air and water, oxidation of the metal sulphides within the rock structure generate acidity. Colonies of bacteria greatly accelerate the decomposition of the metal ions. This generates a waste stream containing dissolved iron, copper, aluminium and zinc in an acid background with a pH range of 1 to 3, and flow rates between 100 – 1000m3/h.

The Copper (Cu) concentration can vary from a few mg/l up 1000mg/l of dissolved Cu.

In most cases AMD streams are neutralised before being released to the environment, resulting in a metal precipitate that eventually builds up as sludge in a tailings pond. Sludge is dewatered producing a waste requiring hazardous landfill disposal.

The Lancy Technology approach is to recover the value of the Cu by selectively removing it from the AMD producing a valuable saleable high purity Cu cathode. Other metals and minerals can be recovered if economical.