Monday, 14 March 2016
Membrane technology has become widely used in various industries in recent years, but has been slow to be adopted in the ever conservative mining industry. One of the main advantages of membrane technology is that it works without the addition of chemicals and with relatively low energy use.
Membranes are used more and more often for the creation of process water from groundwater, surface water or wastewater, and they are now competitive with conventional techniques. The membrane separation process is based on the presence of semi-permeable membranes, the principle being quite simple: the membrane acts as a very specific filter that will let water flow through, while it catches suspended solids and all other salts and ions, creating a concentrated stream and a pure water stream. There are various methods to enable substances to penetrate a membrane. Examples of these methods are the applications of high pressure, the maintenance of a concentration gradient on both sides of the membrane and the introduction of an electric potential.
We are therefore delighted to introduce a new company to the MEI fold, Genesys International, who will be sponsoring Sustainable Minerals '16 in Falmouth in June. Genesys is an industry leader in the development and manufacture of speciality antiscalant and cleaning chemicals for Reverse Osmosis (RO), Nano-Filtration (NF) and Ultra-Filtration (UF) membrane systems.
In the past 5 years there has been a dramatic increase in the number of RO, NF, UF Membrane systems used in mining, and in a paper at the conference, Stephen Chesters will identify over 300 mines with potential to use RO/NF/UF membrane technology. There are sixty-one operational membrane plants and fifty-one of these have been commissioned in the last ten years, 65% of which are in gold and copper mines. In precious metal mines, waste water can be concentrated using membrane plant so additional metals can be recovered from barren liquor. Acid mine drainage (AMD) is increasingly treated and then reused or sent off site as a potable supply to the surrounding communities.
Membrane plants can suffer from rapid fouling and calcium sulphate (gypsum) scale. The reasons for this will be explored and new techniques for preventing sulphate scale and to clean fouled membranes will be introduced. Genesys has recently launched a new and innovative method for RO membrane cleaning incorporating micro-bubbles and effervescent reagents to enhance deposit removal. The company is looking to grow its business in the mining industry and is currently working on a number of research projects and is keen to form alliances to service the mining industry world-wide.