Though many of today's mining projects typically require geomembranes, there are installation considerations you'll need to think about that can cause issues if you're not careful. Some issues that arise during the installation process can slow down or stop work completely. Given the high expense of equipment rental and labor, delays can become very costly, very quickly for the company. However, there are several common issues that tend to show up on mining sites that have good solutions, provided that you know what they are. By preparing for these common challenges during installation, you can either avoid them altogether or have ready solutions available to deal with them as they arise, streamlining the installation process as much as possible.
Rocky or Uneven Soil
As one of the most difficult issues with installation, uneven soil and many rocks can cause even the best geomembranes to tear during the installation process or create wear punctures that can develop with shifts over a few years of use. Though the stones in the soil can seem small or smooth, the rough surface can cause virtually invisible damage to geomembranes being dragged over them. Poor grading and leveling can also create areas where the liner is receiving uneven support. Removing large or sharp rocks without fully regrading the soil can leave a void below the surface, which, even being only a few inches deep, can cause the liner to bulge and creating a stress point that will eventually leak. Take extra time and care to smooth and grade the soil or add a cushioning, geotextile underlayment to help correct this potentially costly problem.
Collapsing, Shifting, or Unstable Soils
Though you could have the most perfectly graded pond for your operation, adding water can cause your liner to suddenly dip and tear from unstable, shifting soils, or from voids beneath the surface. If these areas of collapse happen around the banks of your pond, it can cause wastewater or contaminated material to escape, resulting in environmental or health hazards. Even a small collapse in the middle of your pond can cause leaks to occur. Before you install your pond or any other structure, take the time to test the soil's compaction and composition beforehand. This ensures that the structure you're building will bear up to the weight of the finished structure. If the unstable soil seems to be localized, try compacting it and then regrading to get better support for your structure.
Total Storage Volume
Mining is industrial sized, and the simple size and volume requirements can make it difficult to plan and build ponds that remain leak proof. You can't easily keep track of every yard of geomembrane-covered base and bank that is being installed, especially on larger facilities where you have numerous ponds covering many acres together. When an installation this large is going into place, it's difficult to pay attention to specific areas that could have damage or where a seam may be weak. Make the investment to increase the amount of labor you have available, enlist expert help from BTL's professional team, or leverage technology such as drones to help you track the entire installation process. By putting a bit more time and effort into quality control during your installation process, you'll see benefits in the longer lifespan of the installation, as well as reduced repairs and maintenance issues.
Chemical/Mineral Combinations
There is a wide range of abrasive minerals and corrosive chemicals used in mining. If you're going through the process of renovating an older mine's process and storage pond, your new geomembrane will come into contact with existing sediments and chemicals, which can reduce the lifespan of your new liner. Take the time to remove as much of these residues as you possibly can to extend the lifespan of your geomembrane. You could also put a cheap layer of geotextile between the older and newer layers to help reduce the contact with the new layer, allowing the inexpensive layer to degrade while protecting the more expensive geomembrane from harm. In many cases, the cost of purchasing and installing the geotextile can be significantly lower than the cost of thoroughly cleaning the older pond, and you'll gain better protection in the long run.
Heavy Weight Loads
Water weighs eight pounds per gallon. That's 56 pounds per cubic foot or 1,512 pounds per cubic yard. How big are your ponds? Consider that ore will sink in water, so it's heavier yet. What this adds up to is way more than a ton of weight on your geomembranes. This can cause the membranes to tear, rip, split, stretch and seep as small holes open in its surface. By using reinforced liners, especially reinforced polyethylene (RPE) geomembranes, you will have the most success resisting this huge amount of weight and pressure. This is because the reinforcement grids incorporated in the structure of the membrane work in all directions, distributing the force evenly, instead of placing all of the pressure in one location that will gap, tear or stretch under the pressure.
Leak Detection Equipment
Because mining works with both waste and processing materials that can be very hazardous to human health, catching leaks in your containment system as quickly as possible is essential. For that reason, many states are now requiring either passive or active leak detection to be built into holding tanks, ponds, or similar structures. For these systems, double-layered geomembranes are often used with a drain tile or a texturized geotextile located between them to keep the gap open. Test wells are incorporated at particular intervals for water capture, which is where sensors are located to set off alarms if any leaks happen to occur. At the bottom layer of this system, you're going to need something reliable enough that it will catch any liquid that has accumulated and act as a secondary containment for the water. To get the best results, use the same RPE material for both layers of the leak detection system.
Secondary Containment
Speaking of secondary containment, no matter what kind of material your mine is producing, you'll need to have a solid containment system in place to meet requirements due to the hazards of mining facility waste. To keep the runoff and processing water from your mine from escaping into the environment around it, you'll need more advanced, larger secondary containment methods in place than other industries would require. To meet these requirements, these methods can often be linked together so that the state or federal regulations on volume requirements are met. If you're planning on using a geomembrane for this secondary containment method in your reclamation and rehabilitation process, make sure that the liner you select will handle being buried deeply, as the overall weight and rougher soils can cause tears in weaker materials. BTL Liner's RPE products are designed to handle the challenges of secondary containment, providing you with solid solutions to this often-onerous process.
Heavy Equipment Use
Do you know how big most mining ponds are? Big enough that the liners will weigh hundreds if not thousands of pounds. This means that for some or all of the geomembrane installation, you're going to need heavy equipment to get the job done. At the same time, using the heavy equipment for carrying and spreading out the material will increase the chances that you'll have damage before water is added to the pond. Covering an entire mining site can be just as daunting. Reach out to our expert installation team at BTL Liners for assistance, or at least take the time to plan out any heavy equipment use and coordinate your access paths so that you can avoid having tracks and tires driven over your geomembranes. When stretched against rocks or voids, just a person's weight can create punctures. Once you've covered the surface, limit traffic by working from the center towards the outside using multiple teams to get the job done without damaging your geomembrane.
Job Site Seam Sealing
Seams. Hundreds and thousands of linear feet of seams between each piece of pond liner. Trying to seal all of these seams effectively can double your installation time, significantly increasing labor time as well as the chance that one of those seams will fail over time. Do your best to reduce how many seams you'll need to seal on site, no matter what kind of containment area you're putting together. Getting customized fabrication from BTL Liners can give you a heavier load and are larger folded stacks, but it's well worth the additional work for transportation and unfolding in the long run. The reduced number of seams also reduces your testing and maintenance over the entire lifespan of your structure, and it also streamlines your installation process dramatically, allowing you to get into operation either in the mine or as its post-mining reinvention.
Concrete Reinforcement
Though many engineering specifications for larger holding ponds or tanks will require concrete for stability as well as strength, concrete is a bad liner for mining applications. It's naturally porous from tiny air bubbles in mixing, which creates a capillary action if the outside of the material if it isn't coated in some fashion. This creates a serious issue for seepage and leaks over time. It's also very reactive to a lot of chemicals and ingredients that are used in both mining fluids and mine waste products, which can quickly cause problems. Starting with spalling, cracking will appear which can lead to leaks and weaken the overall concrete structure. By adding protective coatings to the surface and using geomembrane beneath the concrete, you can drastically reduce the amount of leakage, solving both issues at the same time. This way, you'll gain the strength of the concrete while protecting it from damage and protecting the environment from possible leaks over time.
Using mining geomembranes in your reclamation and rehabilitation process can seem difficult, but by knowing the tricks involved in the installation process, you can make sure that you're getting a quality installation that will last many years to come - quite possibly longer than your mine. If you're having issues with figuring out your installation process for your RPE geomembrane, the experienced professionals at BTL Liners are ready to help. Please feel free to contact us today for assistance.
In Conclusion
Mining reclamation and rehabilitation is a big part of keeping the mining industry working well with environmental groups and moving into a more sustainable future. By taking this responsibility for the restoration of the land seriously, the mining industry can steward the natural resources we've all been blessed with. Though this has not always been an easy task, it's one that has become much easier as time has rolled forward and new options have become available to the industry as a whole; giving the process of reclamation and rehabilitation a solid leg up.
Over the past century, the environmental and human costs of mining and mineral processes have built up and come into focus, but as a society, we still require the metals and minerals being processed to handle the demand we create for electric cars, technology, new homes, connectivity, and even food and nutrition. Meeting this demand while also falling within stricter limitations on greenhouse gas emissions and energy usage will create challenges for the industry to face now and long into the future. With the development of new technologies and materials to help the mining industry through this process, you'll be able to meet industry regulations and improve efficiency.
We must deal with the end of the mine life cycle as older, existing mines require more extensive remediation, reclamation, and rehabilitation process. This means, turning the area that was once a productive mine into land for agriculture, recreation, tourism, utility or other option that continues to provide support for the local and regional community in one fashion or another. Geomembranes play a strong role in that process, creating a seal that can help create safe, secure storage for the contamination from past mining ventures and allowing the land to be used for other purposes.
By considering the potential benefits of geomembrane technology in mining reclamation and rehabilitation work, we can develop new solutions in the mining industry. At BTL Liners, we have a long history of innovation combined with a strong commitment to helping customers in all industries succeed. We're happy to work with you at any stage and design of your business, to help find a beneficial solution that meets your needs. Whether you're looking at traditional tailings ponds, caps for your mining operation, or preventing soil or air contamination, we have geomembrane options that can help you find the right solutions for your business. Please feel free to contact us today, and we'll work with you to find the best products for your specific operations and goals.
