One solution to these issues is the use of geomembranes, which can be used both in progressive as well as traditional mining reclamation and rehabilitation practices. Though you'll find geomembranes mentioned dozens of times in standards and recommendations for mining facilities, it's not always clear exactly what you need. Because it's not a single material or product line, it can cover dozens of materials that share a number of characteristics. If you assume that every geomembrane is interchangeable, you'll face significant challenges in your mining environment as well as expensive failures on your site. Here's a quick glance at common mining geomembranes to help you choose the right option for your mine's needs.
What are Geomembranes?
Geomembranes are flexible, impermeable materials that are used to stabilize, secure or seal earth and similar geological material into a location. Created from woven, extruded, or spun material, they are intended for contact directly with the earth or paired with underlayment in some applications. If it cannot provide a seal to prevent contaminants from leaching out into the environment, it is not a true geomembrane, but a geotextile, an important difference when it comes to site reclamation and remediation.
Geomembranes are manufactured using three different methods: spread coating, sheet extrusion, and calendaring. Geomembranes tend in general to have very different ranges in flexibility, resistance to UV damage, may or may not have reinforcement, use a range of polymer contents, and may or may not provide plant and fish safety ratings. The category covers a wide range of products with applications across dozens of industries with hundreds of possible uses. However, for mining use, you'll commonly find characteristics including limited flexibility based on thickness and stiffness of the membrane, carbon black additives which increases UV resistance and degradation, low to no permeability to reduce water passage through the membrane, vapor movement prevention, textured surface to prevent erosion, stretch resistance to a particular rating and reinforcement. We will discuss all of these factors in more detail later on. However, if you want a quick starting point, look no further than ArmorPro from BTL. These liners are up to even the toughest task, with superior UV resistance, high tensile strength, excellent tear resistance, robust puncture protection and more.
A Part of the Family of Geosynthetics
Going more broadly, geomembranes are a part of the geosynthetic family, which covers the entire catalog of polymer-based materials that are intended to stabilize soil and embankments in some fashion. Geomembranes specifically are solid planar sheets that are laminated or extruded in most cases, rather than woven, which can cause seepage and leaks. Commonly found in use for containment pads and liners, they can also be used as covers. Because they are highly impermeable, they work well for controlling leaks and leaching, which is why they're so popular in handling groundwater contamination issues from mining. However, they can also be used hand in hand with a range of other geosynthetic substances to help stabilize the soil and prevent contamination of soil, water, and air.
This high level of impermeability is why they're so popular in mining reclamation and rehabilitation. They can control water flow both into and out of the mine site. This is especially helpful below leach pads and tailings ponds, as it allows you to extract the maximum of the metals you're mining while preventing minerals, chemicals, and other compounds from entering the soil with the water, as would happen with a permeable membrane. If evaporation or production of gas is an issue, it can be used as a vapor control barrier. This is part of the reason why the mining industry is responsible for about 40% of geomembrane use; because of the material's flexibility and functionality.
Geomembranes are a solid part of mining's future, delivering amazing options for containing potential contamination sources. BTL Liners offers a vast assortment of geomembranes that offer impermeable performance to minimize seepage on your mine site as much as possible, making reclamation and rehabilitation significantly easier and less expensive than other options. Whether you're in current operations or are concerned about risks to the water table following rehabilitation, our liners provide the water loss control you need to leave a clean site behind for many purposes.