Geosynthetics offer terrain stabilisation and barrier protection which is reliable and long-lasting, unlike traditional natural materials like wood or cotton. Since the advent of polymers, and subsequently geosynthetics, in the 20th century, their strength and durability have been widely used in the civil engineering sector. And yet, their uptake in the mining industry has been somewhat slower. Despite this, the use of geosynthetics is steadily growing within the mining industry, as operators begin to understand their value.
Geosynthetic products are versatile, and have applications across a number of fields. They can be broken down into eight specific categories:
- Geosynthetic clay liners
In the civil engineering sector, geosynthetics are used to reinforce walls, provide drainage which is less affected by bio-degradation, and even form barriers for liquids and gasses.
In the mining industry, perhaps the most valuable geosynthetics application is in creating durable waste barriers for mining by-product. Mining regularly produces more solid waste product than any other industry around the world, and waste containment and disposal presents an ongoing challenge for mining organisations. According to an article by Geosynthetica.net:
“If one considers that in order to recover a gram or two of gold, one tonne of mineral bearing rock must be crushed and processed, and at least another tonne of waste rock is produced, an idea can be gained of the enormity of the waste management problem faced by the mining industry.”
Waste rock and ‘tailings’ are two of the most significant waste products produced during the mining process. Tailings, in particular, are difficult to manage due to their fine particles. Generally dumped in a water-based slurry, tailings can also contain leftover chemicals from processing and therefore need to be contained effectively to avoid damaging the surrounding landscape, degrading soil and affecting waterways.
Geomembranes, in particular, create a uniquely impermeable barrier which can be used to contain waste products generated in the mining process, as well as to line concrete basins, tanks, and even to create solar or evaporation ponds (for salt recovery, for example).
Geomembranes can prevent leaching of harmful chemicals into the soil beneath waste basins, and for this reason, their use is becoming more prevalent within mining. Geosynthetica.net’s article continues to explain how geomembranes can also be used to recover and collect materials;
“The geomembrane lining material is used to retain chemical solution used to dissolve minerals from ore, and to allow the leachate to be collected and refined. Heap leaching presents a combination of extreme base pressures and high moisture/acidity conditions on the geomembrane not present in any other containment application.”
Geosynthetics manufacturers continue to develop geomembranes which are stronger, and more suitable to the harsh conditions presented by mining operations. Extreme temperatures, acidic product and terrain which can cause punctures, all pose challenges to the suitability of liners in mining applications. As mining waste continues to grow in scale, geosynthetics offer an effective solution to waste containment challenges, in ways that no natural materials can. As their strength, durability and efficacy continues to improve with advances in technology and production techniques, geosynthetics will become yet more prevalent in mining operations the world over.