New mining technologies and regulations have significantly improved mining efficiency and reduced environmental impact in recent years. In general, mining techniques become much more environmentally sensitive when efficiency is improved because less waste is produced. However, even greater improvements must be made as part of Mission 2016's plan. The current "green" mining techniques need to become more widespread and there will be a focus on researching new environmentally friendly techniques.
The plan for improving efficiency and decreasing the environmental impact of mining is broken up into the following categories:
- Shutting down illegal and unregulated mines
- Choosing environmentally friendly general mining processes
- Implementing recently discovered green mining technologies
- Cleaning up the sites of shut-down mines
- Reevaluating Cut-off Grades
- Research and Development of Green Mining Technology
The plan below is described with respect to REEs in order to illustrate a specific example. However, many of the same problems are inherent in mining of other strategic elements, and thus Mission 2016's solutions can be applied and implemented for these mines as well.
Two major methods of implementing green mining reform are governmental regulation and innovative technologies. Better regulation generally precedes cleaner mining practices. China's new regulations for their mines are a good example of ideal government intervention with regards to the specific ideas that the laws encode (enforcement has not been considered). Molycorp provides a good example of the use of environmental-friendly technologies and policies in their working following the reopening of the Mountain Pass site. Both of these examples have thus far proven reasonably successful in terms of reducing the environmental effects of mining while suiting both business and governmental motivations.
Case Study: China
Before the most recent regulations set by the Ministry of Industry and Information Technology in 2010, mining facilities in China - especially for REEs - were almost completely unregulated in terms of environmental consciousness and efficiency. After years of lax regulation and undisciplined treatment of illegal, unpermitted mines, China's government responded to a wave of public protest and – partly in its own self-interest – enacted new policy measures for greener mining. These were codified in the Rare Earth Industrial Development Policy (Schuler, Buchert, Liu, Dittrich & Merz, 2011). The following regulations are the most important out of those now in practice. They are being enforced to discourage illegal and environmentally careless mining. These are cited from the Oko Institute's Study on Rare Earths and Recycling.
- From 2009 to 2015, China will not issue any new mining licences for rare earths.
- Efforts to shut down illegal mines and inefficient separating and smelting enterprises will continue.
- Increased monitoring of the industry will be done by the Ministry of Industry and Information Technology.
- Requirements for an efficient electricity supply and specifications concerning the maximum energy demand per ton of rare earths produced are also indicated.
- Minimum recycling rate for ore dressing waste water of mixed rare earth minerals (85%) and bastnaesite and ion adsorption deposits (90%) are set, as well as yield rates (92%).
Pure monazite (one of the main sources of REEs) mining has been banned because of its high concentration of radioactivity. Bastnaesite, one of the two main minerals used for rare earth extraction, should be extracted with a treatment system that can completely treat wastewater and solid wastes for toxic and radioactive elements.
In-situ leaching mining (see the mining background page) has been introduced as the required mining method for those new mines that can physically implement this technology.
Saponification, a step of the refining process that leaves the wastewater highly toxic, can be improved through a newly discovered method that eliminates the need for ammonia. All mines will transfer to this process to minimize the toxicity of the wastewater.
Fluorine containing solid wastes should not be mixed with other waste products during disposal so as to reduce the contamination of the other, potentially reusable waste products.
Vegetation surrounding the mined areas must be rehabilitated to minimize the change in the surroundings caused by the mine. This will also make the community around the mine more habitable.
(Schuler, Buchert, Liu, Dittrich & Merz, 2011).
These measures have not all been fully implemented, but China has set a ten-year timeline so that by 2020 they are fully enforced. Already, one third of China's 23 mines have been identified as mines to be shut down (Volgt, 2012). China has also increased funding for research of different leaching-extraction processes, new uses for stockpiled cerium, recycling of wastewater, and more effective ways to recover fluorine and thorium. Although China's past environmental regulation was severely lacking, its proposal protocol for reducing harm to the environment, if followed, would reduce waste at many mine sites, as it addresses some of the most common causes of mining-related waste.
Case Study: Molycorp
Mountain Pass, a mine in the Clark Mountain Range in California, United States was shut down in 2002. At the time, it was owned by Chevron. At its peak, it was producing most of the world's supply of rare earth metals. Mountain Pass closed in part because Chinese mines flooded the market with cheaper materials and partly because of a large environmental mishap (Danelski, 2009). "When the Mountain Pass mine in the United States was operating at full capacity in the 1990s, it produced as much as 850 gallons of salty wastewater per minute, which also contained radioactive thorium and uranium" (3, Morrison, 2012). This waste leaked into the desert, costing Molycorp hundreds of millions and harming the local environment.
Molycorp acquired the land in 2008, and plans to reopen at full capacity (20,000 MT a year) by 2013. They plan to expand the open-pit mine in three directions as well as deepen it (Paul and Campbell, 2011). Their recovery rate (percentage of extracted material that can be refined) of 90 percent will surpass many currently operating REE mines as will the environmental standards they propose if they are implemented as planned ("Molycorp financial summary," 2011). Some major changes in their environmental mining policy since closing in 2002 include:
- Changes in tailings storage. Paste-tailings are now dried out and laid flat in a facility, which makes them less volatile and and more compact. This reduces:
- The supply of fresh water needed, since the water from tailings can be recycled
- Chemical reagents in tailings that can be recycled along with the water
- Eliminates the need for 120 evaporation ponds ("Molycorp Innovations," 2012).
- New technologies which use the excess cerium in stockpiles. Xsorbx uses cerium's magnetic properties to remove phosphorus from water ("Molycorp annual report," 2011).
- Using waste heat from mining to generate steam and power, thus decreasing the carbon footprint.
In addition to being less environmentally damaging, these changes also reduce Molycorp's production cost by saving on water, chemical reagents, heat, power and total area used for stockpiling and waste piles. As such, these regulations are both environmentally friendly and economically feasible.
Summary of Molycorp's Green Mining Methods:
Molycorp increased funding to these sectors of research and development and reported allotting $8.3 million towards these areas in 2011. Although not all of the technology is in use yet, this research helped develop some of the new technology listed above (Molycorp Annual Report, 2012).
As detailed above, China has started to develop better regulations and practices to achieve their goals and Molycorp plans to use research and technology to save money and reduce environmental harm. Mission 2016 proposes building from these precedents and adapting them to fit the evolving needs into the future while also acting upon the following plans to help make mining more environmentally sustainable and financially viable.
Shutting Down Illegal and Unregulated Mines
Illegal mining must also be addressed as a part of an environmentally conscious mining solution. China in particular has many illegal mines that currently produce a significant share of the global supply of strategic metals. These mines also lack environmental, human rights, and quality standards. Additionally, they hurt China's plan to improve their mining regulations (Schuler, Buchert, Liu, Dittrich & Merz, 2011). Similar problems with illegal mining occur worldwide, particularly in countries with little or no mining regulations.
The context of illegal mining varies based on location and culture, and therefore some standard regulations must be established to deal with these mines at the most basic level (see the mining regulations page). Illegal mining sites must be investigated. If the mines are deemed operational by the international regulatory body (see international regulatory body section), they will be legalized and forced to adhere to the new environmental standards. Otherwise, they must be shut down and restructured according to the plan listed below in this section.
In addition, in areas with poor regulations, mining standards must be enforced and currently operating legal mines evaluated for environmental hazards (see mining regulations page).
Choosing Environmentally Friendly Mining Processes
Another broad method for improving efficiency would be to address the general mining process and purification processes. Although open pit mining (link to mining solution page) contributes about 85% of all mineral mining, it is one of the most environmentally taxing. About 73% of extracted rock goes to waste. Meanwhile, underground mining wastes only 7% of the extracted rock but is more expensive (Hartmann and Mutmansky, 2002). In situ mining (see mining solution page) can be more environmentally friendly than underground mining and is cheaper than many mining methods (Ulmer-Scholle, 2008). However, in situ mining cannot be implemented in all cases as the ore needs to be beneath the water table (the level at which the ground is saturated with water) and it needs to be porous enough to let the leaching solution dissolve (Topf, 2011). Unfortunately, in situ leaching can also be very harmful if the solution leaks into the water supply. There are plenty of examples of past leaks at in situ leaching mines ("Colorodoans against resource destruction", 2008).
It is infeasible to convert all current mines to more environmentally friendly mining methods due to economic constraints and ore deposit geography. However, when opening new mines in areas with low risks of water contamination, in-situ leaching should be the choice method when physically possible. If not, then the environmental benefits of underground mining need to be weighed with the financial benefits of open pit mining to determine the mining method of choice on a mine-by-mine basis.
Reevaluating Cut-off Grades
A mill cut-off grade is a level set that is considered to be the lowest quality of already mined ore that is economically feasible to continue processing. Different materials have different properties that determine a feasible cut-off grade. Often these grades are set at over-conservative levels. The easiest way to improve efficiency in mining and to decrease waste products is to decrease a mine's mill cut-off grade. Re-evaluating these grades at each mine will significantly reduce waste. A lower mill cut off grade may decrease the quality of the material, but certain final uses of the material do not need a very pure compound. Cut-off grades will be determined on a mine-by-mine basis by looking at precedents for the material in question and taking the future use of the material into consideration.
Implementing Recently Discovered Green Mining Technologies
These recent technologies include:
- Mining from tailings: Sometimes amounts of the metals being mined end up in the wastes. Reprocessing these wastes can result in more usable material.
- Dust suppression techniques: During the mining process, large amounts of dust are released into the atmosphere. This can be minimized by pre-wetting the areas to be blasted with high volume sprinklers. Once the dust is in the air, the only way to remove it is through mist cannons. Current mines using open pit mining techniques can reduce dust through by purchasing high volume sprinklers and Wet Earth Fog Cannons. These two systems would cost a mine approximately 600,000 USD (Dust Suppression Solutions, 2003).
- Liquid membrane emulsion technology: This is a separation technique that can be used to extract usable metal from highly toxic or acidic waste water produced by a mine. This technology can even deal with dilute solutions (Venezuela, Araneda, Vargas, Basualto, and Sapag, 2009).
- Sulphuric acid leaching extraction process: Currently, bastnaesite is generally processed in a hydrochloric acid leaching process. This process leaves fluorine and thorium contaminated wastes and it creates cerium of low purity. However, a sulphuric acid leaching extraction process can produce high purity cerium while also allowing thorium to be separated for use and better containment (Schuler, Buchert, Liu, Dittrich & Merz, 2011).
- Impermeable tailings storage: Tailings are often stored in some form of tailings pond. Radioactive elements in this pond can pollute the water and if leaks occur, the surrounding area (see the mining problems page). Tailings will be required to be stored in impermeable tailing ponds. These ponds become impermeable by adding a layer to the boundaries that does not let liquid through. Alternatively, the tailings can be dehydrated into a paste, as done by Molycorp. Molycorp's tailing process was reported to cost approximately 10 million USD (Molycorp Annual Report, 2011).
- Choice of ventilation and diesel engines: 10 percent of mining costs come from electricity consumption. Better ventilation systems and diesel engines could be purchased by mines to maximize efficiency. The Canadian Mining Initiative has created a list of approved diesel engines (Green Mining Initiative, 2012).
It would be unreasonable to expect all strategic mineral mines to adopt every one of these mining technologies. However, the international environmental group described in the section on "Cleaning Up Sites of Shut Down-Mines" below will give each technology a point value based on how much it reduces the negative environmental impact. Mission 2016 suggests that expensive, highly impactful modifications, such as building a system to begin mining from tailings, are worth a high amount of points (perhaps 100 points) while a simple modification such as re-evaluating a mill cut-off grade is worth 10 points. Once a mine achieves 100 points for implementing these technologies, the environmental group will lobby the government of that mine to provide a tax break, thus incentivizing greener mining techniques (which, in some cases, are already economically favorable to mines).
New mines to be opened up will be required to fulfill a certain amount of points before opening. This can be enforced through established environmental regulations (see the environmental regulations page).
Research and Development of Green Mining Technology
Research and development of new green mining technology in the areas of processing, clean water, and energy efficiency will be continued (Green Mining Initiative, 2011). For example, since the 1980s, Australia has been allocating millions of dollars towards mining research and this research has aided in the development of new, more efficient surveying and drilling techniques (Hogan, 2004). This must be an ongoing solution. As technologies are developed, they will be added to the point system described above in the implementing recently discovered green mining technologies section.
Cleaning up shut-down mine sites
Many areas that used to have mines are now contaminated. People live in these areas, despite the fact that the water and soil may have high concentrations of unsafe chemicals and heavy metals such as lead. R2 technology is a process that subjects mine wastes to physical and chemical processes that recover the metals while improving the condition of the land (Re-Use and Reprocess R2 Technologies, 2009).
Mission 2016 suggests that an international non-governmental environmental group concerned with mine clean-up and implementing green mining technology will be started and funded by governments, private donations, proceeds from reclaimed materials, and mining companies. Mining companies will have interest in this group because it will provide a rating for mines. This rating system will be analogous to the way the US eating establishments are rated for safety. Mines will be rated based on how minimal their environmental impacts are. The environmental group will lobby governments to give tax breaks to mines with especially high ratings. This group will also fund the use of R^2 technology to clean-up toxic areas. It costs approximately 3.40 per yard USD of clean-up initially and then 0.40 USD per yard per year for the next thirty years (Re-Use and Reprocess (R2) Technologies, 2009). This will create jobs and improve the affected land. Any money made from the materials reclaimed in the cleanup process will be sold by the environmental group to make the group more self-sufficient. This will not have any adverse effects on the governments of the abandoned mines being cleaned as these mines will have already been shut down.
- Shutting down illegal mines: The associated costs are included regulatory costs of mining, but countries with a significant amount of these mines may suffer from loss of revenue.
- Choosing environmentally friendly mining processes: Opening an in-situ leaching mine is projected to cost 25-35 million USD versus a typical open pit mine which costs about 500 million USD (Uranium Mining, 2006).
- Reevaluating cut-off grades: included in regulatory costs.
- Implementing recently discovered green mining technology: each method has its own associated costs that vary based on where they are to be implemented.
- Research and development: The amount of money allocated for R&D by governments will be 10 percent of all tax revenue received from mining companies and related industries (such as refining). This figure will vary depending on the number of mines in a country. Individual mines also may be interested in allocating money for this purpose, in order to reduce environmental impact and costs. For example, Molycorp reported spending amounts varying between 1.5 million USD and 12.6 million USD annually since 2008 on research and development (Molycorp Annual Report, 2011). Although this number is not representative of every mine, Molycorp has successfully developed green technologies to be used in their mine upon opening, with an R&D budget that is only a fraction of what the overall operating costs of a mine are.
- Cleaning up shut-down mine site: Assuming the government starts the cleanup of 2 mines approximately 1.25 square kilometers large, this group would require approximately 8 million USD in funding from the companies who owned the mine, as well as from private investors.
Timeline and Projected Effects
Even with the best intentions, the status quo indicates that new mines are likely to open without stringent environmental standards, especially in countries with few or no mines. Mines in under-developed or under-regulated countries (where most strategic mineral deposits are located) will not begin with stringent environmental standards. Therefore, the time to set up an environmentally conscious mine can be estimated from case studies as such:
China and the United States are the two best examples of environmental-mining evolution from which to extrapolate. The United States began mining at Mountain pass in 1965, and did not stop to consider environmental concerns until 2002. China began mining in 1985, and then earnestly with the Bayan-Obo deposit in 1991, and only imposed environmental regulations in 2010.
There are some things to consider, which make these case studies imperfect predictors of future mine operations:
- Mountain Pass, while not perfect, did not cause environmental damage on the scale of China's numerous, illegal/unregulated mines until 2002.
- China's government is much less willing to impose environmental regulations.
- Countries in the future will have both of these examples to learn from.
However, some of these concerns (like a and b) balance the other's skewing impact.
So opening new, cleaner mines will likely occur over a 15-25 year timeline. This process will be sped up by open-source technology and an international regulatory body.
By 2015: The environmental group dedicated to mine clean up and ratings is organized. Governments and mining companies can begin devising a financial scheme for initial funding of this group. Countries interested in mining include a budget for research and development in their plans. An environmental regulatory body will oversee the creation of a point system for implementing green technology detailed above (see Environmental Regulations page). Illegal and unregulated mines will begin to be shut down or legalized. Cut-off grades are reevaluated. Current mines begin implementing the green technology techniques, and new mines will include them in their initial start-up costs.
By 2020: The environmental group dedicated to mine cleanup begins the first mine cleanup project. The point system begins to be used as a method for evaluating a mine's environmental effects. All current mines are expected to be held to the new, stricter standards, while the international regulatory body in conjunction with the different governments should have shut down almost all unregulated mines.
2025-2035: Cleaner mining practices will become more commonplace as previously unregulated mines reopen.
Past 2030: All implemented procedures continue to grow and develop. Illegal mining should be completely shut down and regulations will have improved the environmental footprint of mining. Atmospheric emissions and wastewater will be minimized. Shut down mines will be cleaned and reclaimed by the local community.
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