Industrial Minerals in environmental engineering

IM are crucial in water management, whether one considers drinking water preparation or waste water treatment. For example, silica sands are used as filters, perlite, zeolites or talc as floculants or adsorbents, bentonite as a degreasing agent, calcium carbonate as a neutralising agent, to mention but a few.

IM-based liners and geosynthetic liners, either basal or superficial, are increasingly used to impede the escape of leachate from landfill sites. They are made of superimposed layers of IM, and sometimes synthetic materials, the composition and sequence of which has a dramatic influence on its efficiency.

Air treatment of industrial effluents also largely relies on minerals. Activated carbon is the best known technique, but other minerals are used as well, for example, flue gas desulfurisation of power station fumes is achieved with calcium carbonate. This latter application even results in the production of gypsum.

When possible, IM supply is also organised through integrated systems, as is the case in some paper plants (whose CO2 emissions are used to precipitate calcium carbonate which is in turn used in the manufacture of paper).

Image: