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Mine Ventilation Methods: Why Australia is Great But Could Do Better
Coal mining is inherently dangerous. Fumes from mines and coal dust are some of the worst environmental and health hazards of any industry. Thankfully, Australian businesses do a very good job of protecting workers with excellent ventilation systems. However, things could be better.
The Good
Mining is a dangerous profession, but most companies have excellent technology to vent the gases found naturally in mines. What gasses? Methane is a major one, and it can be particularly deadly. Breathing methane can cause respiratory problems or even asphyxiation.
Venting systems today typically rely on a single system or double layered system for venting gases into the atmosphere. Single venting systems have one point of failure, so they aren’t as common as layered systems with secondary venting.
The first or primary vent is backed up by a secondary vent to take stress off of the primary system. These systems efficiently move air from deep inside the mine out to the atmosphere to preserve miners’ ability to work unencumbered in a clean environment.
New Technologies
Some companies are hiring third-party technology companies to make industrial-grade apps for their new conversion technologies. Monitoring clean air is a big part of the mining business, and some companies are moving beyond simple venting systems. One of the newer technologies for removing methane is chemical looping.
Chemical looping is a chemical reaction that changes methane into carbon dioxide. This carbon dioxide can then be moved out of the mine easily. And, while methane can be easily ignited, there are many times when this is undesirable.
In these cases, a metal oxide, like iron or copper reacts with the methane and then transforms the gas into carbon dioxide. It’s not a true combustion, but it works in a similar fashion, chemically speaking.
Chemical looping reaches peak efficiency around 500-600 degrees C. This is advantageous over traditional combustion where temperatures can exceed 1100 degrees. Still, why not just clear out the mine and use cheaper combustion methods?
For starters, methane is easily combustible, but only at concentrations of 10 to 15 percent or more. In some mines, concentration is 1 percent, so methane must be converted using chemical reactions that operate at lower concentrations.
The Bad
Unfortunately, not all companies are on the cutting edge. Just as in any industry, there are companies that use lower-tech solutions or use duel venting systems but have problems with installation.
In fact, a common problem with current technology isn’t the tech itself, but rather the way it’s used. Some companies do install poly ducting, which is unsafe because of its variable burning characteristics in flame testing.
The most common errors on mining sites are maintenance and installation though. Some pipes are installed in such a way so as to impede good airflow. These pipes are installed with “kinks” or bends in the piping that would normally be OK for non-critical ventilation systems, but which impede airflow when something like methane is trying to be vented.
Bending straight ducting around corners can be fixed with better engineering and systems planning when the mine opens.
Another problem is improper use of safety equipment by miners (including not using provided safety equipment). If these trends can be fixed, there’s no reason why existing technology could not be used for a very long time.
The Future
Just because existing tech works, doesn’t mean it couldn’t be made better. The goal is zero-risk, even if this may never actually come to fruition. Ever-increasing efficiencies, like enhanced chemical looping look to be the future of mining ventilation systems.
Increasing regulation may also play a role in how mining operations vent methane into the air. With concern for climate change rising, governments all over the world, including the Australian government are regulating greenhouse gasses and looking for ways to minimise output of these gases into the atmosphere. Since chemical looping relies on transforming methane into CO2, there is a concern that this may impact the environment.
The battle between worker safety and the environment may have just begun.
