| lked to North America’s leading In Situ Leach | | | | osmosis equipment acts like an ‘ion |
| (ISL) uranium mining engineers, and had them explain | | | | filter,’ allowing pure water to pass through a |
| exactly how ISL worked. Most of the significant ISL | | | | membrane and filtering out ions of sulfate, calcium, |
| operations in the United States were designed and/or | | | | uranium, bicarbonate and so forth,” Anthony |
| constructed by these engineers. They explained how | | | | explained. |
| ISL mining is really just reversing the process of | | | | Two streams of water are produced by the reverse |
| Mother Nature. | | | | osmosis unit. One stream is called “product |
| CLEANING UP THE PROJECT | | | | water,” and is normally consistent with |
| Not so fast. Shipping the uranium out of the ISL plant | | | | drinking water quality. The smaller stream of water is |
| isn’t the final step. The water has to be | | | | called “brine.” It contains, according to |
| cleaned up, the property returned to its original | | | | Anthony, “95 percent of all the dissolved ions |
| condition. If done properly, then the footprint of the | | | | that were in solution.” He said, “The |
| ISL uranium operation should have been nearly | | | | brine is disposed down a deep well into an |
| erased. In an earlier article, “Wyoming | | | | underground formation, which is typically not suitable |
| Uranium: Now and the Future,” we talked to | | | | for any use.” |
| Pat Drummond at Smith Ranch about this process: | | | | CONCLUSION |
| The company is meticulous in restoring the landscape | | | | For all the lip service and media attention paid to the |
| as well. Any restoration work on the surface is called | | | | environmental movement in terms of financial |
| “reclamation.” That can involve | | | | support, recognition and respect, it is the ISL miner |
| farming. “When we start a well field, we have | | | | who cares more about the environment, about |
| to, by license, remove the topsoil and store it | | | | preserving Mother Nature. Environmentalists remain |
| somewhere,” Drummond explained. | | | | ignorant of, or care not to publicize, the dangers of |
| “When we go back to reclaim the property, | | | | coal-fired electrical generation. Mining and burning coal |
| we take all the pipes out, we take the houses down, | | | | to generate power for industry and residential |
| and cut our wells off. It’s all identified. We | | | | electricity poses a greater threat to Mother Nature |
| put an ID marker on the well. In 50 years time, when | | | | than ISL mining and nuclear power-generated |
| Farmer Joe comes around and wonders what was | | | | electricity. No more evident a case in point is New |
| there, the state can say, ‘That was a | | | | Mexico, where the Navajo Nation |
| uranium well.’ From the time we’ve | | | | “banned” uranium mining, because |
| stopped mining, we put everything back to | | | | their president was misled by environmentalists in |
| normal.” | | | | believing ISL uranium mining could pose a threat to |
| The one item we did not address at the time was | | | | groundwater. At the same time, the Navajo Nation |
| cleaning up the water after the orebody has been | | | | enjoys over $100 million in coal royalties each year, as |
| mined out. Why is restoring the water back to | | | | their air is polluted by carcinogens filling their air from |
| background important? “In the mining | | | | coal mining in the San Juan Basin and coal-fired plants, |
| process, you’re basically elevating | | | | which produce most of their electricity. It is time for |
| sulfate,” explained Anthony. | | | | the world’s environmentalist movements to |
| “You’re also elevating calcium | | | | wake up and smell the air they are breathing. |
| because you’re lowering the pH a little bit, | | | | Unfortunately, ISL uranium mining will not replace |
| down to 6.5 to 7. Because you run it across the ion | | | | conventional uranium mining in many deposits across |
| exchange circuits, you get a little leakage of chlorides | | | | the world. According to the World Nuclear |
| into the lixiviant.” Subsequently, the water will | | | | Association, ISL mining accounted for 21 percent of |
| have sulfate, chloride, calcium and bicarbonate | | | | worldwide uranium mining in 2004. “The |
| circulating within it. “When you add carbon | | | | overriding constraint of ISL is the technology is only |
| dioxide, you’re forming bicarbonate,” | | | | applicable to selected uranium deposits,” |
| Anthony noted. “These are the major ion | | | | Stover cautioned. “It’s those deposits |
| groups you are elevating during the mining | | | | wherein the uranium ore resides in a permeable |
| process.” He also added that in some | | | | environment, where you can flow water through the |
| projects, you may get arsenic, vanadium and/or | | | | deposit and where you can bring the dissolved |
| selenium. “They all go into the solution so that | | | | oxygen and carbon dioxide into contact with the |
| at the end of your mining process, these ions will be | | | | uranium.” Stover explained that, during the |
| elevated above their baseline values.” The | | | | evolution of ISL mining, a number of projects failed |
| water will need to undergo a purification process to | | | | because the uranium was associated with organic |
| return them back to a quality consistent with baseline | | | | material, was not accessible to the leaching solution, |
| values.” | | | | or the uranium was tied up in clays or shale-like |
| What does the ISL operator do with the water once | | | | material. “They were not able to flow fluid |
| the facility has mined out the uranium? There are | | | | through it,” explained Stover. “The |
| three options, which we discussed with Glenn | | | | key issue at the onset is a careful characterization of |
| Catchpole, who has also set up previous ISL | | | | the host environment in which the uranium |
| operations. In 1996, Catchpole was the General | | | | exists.” |
| Manager and Managing Director of the Inkai uranium | | | | The key advantage to ISL is the far lower capital |
| solution mining project in Kazakhstan. He is currently | | | | costs to start up a project, compared to the |
| the Chief Executive of Uranerz Energy. | | | | hundreds of millions required for a conventional mining |
| “Here’s my order of priority: If you | | | | and mill complex. For example, UR-Energy’s |
| have a receiver formation for deep disposal on your | | | | William Boberg and Uranerz Energy’s Glenn |
| project, that’s my first choice.” | | | | Catchpole both believe they can install an ISL |
| Sometimes, a project may not have access to a | | | | operation on their Wyoming properties for as little as |
| deep disposal aquifer, warned Catchpole. | | | | $10 million. Labor costs are also less. Doug Norris |
| The water is sent down the receiver formation, | | | | pointed out, “In its heyday, the Highland mine |
| down about 4000 feet. “You’re | | | | probably had 4,000 working in it.” By |
| usually sending this water to a formation that is very | | | | comparison, Cameco’s Smith-Highland ranch in |
| briny, a poorer quality than what you’re | | | | Wyoming may soon ramp up to nearly 100 |
| sending down,” Anthony pointed out. Another | | | | employees. “We’re talking about |
| option, according to Catchpole, would be operations | | | | installing a centralized water treatment plant |
| ponds, or evaporating ponds, where the water is | | | | supported by a large number of water wells, typically |
| evaporated. A third option is “land | | | | completed with PVC,” Stover explained. |
| applied.” Catchpole explained this was for land | | | | “That’s in contrast with conventional |
| application. “You take your waste stream, | | | | mining, where you have extensive earth moving, in |
| you treat it to remove the certain level of impurities, | | | | the case of an open pit or extensive underground |
| according to the government requirement, and then | | | | workings, and a more complicated, much larger |
| you’re allowed to disperse it on the land | | | | processing plant.” |
| surface, as if you were irrigating.” When | | | | In terms of environmental impact, ISL offers |
| applied to the land, it is soaking into the land. | | | | something sensible to the environmentalists. |
| “It’s growing grass, and it’s | | | | “ISL is much less intrusive, and it is short |
| going into the groundwater system,” | | | | lived,” Stover said, echoing the sentiments of |
| concluded Catchpole, “Whatever water | | | | all who have been involved in this type of uranium |
| quality standard they allow for you to put that water | | | | mining. “It’s acceptance by the |
| in the land, they want to ensure it doesn’t | | | | general public is much more favorable,” he |
| accumulate some particular chemical over time that is | | | | concluded. |
| going to build up and contaminate the land.” | | | | What does the future hold for ISL uranium mining in |
| Generally, during the restoration process, the water is | | | | the United States? “Up until 2004, prices |
| circulated through the barren orebody about eight | | | | were flat,” Norris pointed out. “The |
| times. It’s another instance of pore volumes | | | | economic picture has just now switched to where |
| – eight more times through the sandstone | | | | mines can start coming on again, but it does take |
| formation. Anthony explained, “Normally, the | | | | years to properly define where the ore is. It takes a |
| first pore volume is evacuated and disposed of via a | | | | lot of geologic drilling and time to decipher it. Then |
| disposal well.” But he warned, “This will | | | | there are the regulatory requirements, and that can |
| cause an inflow of surrounding native water back into | | | | take several years. Even if everybody reacted right |
| the mine zone. The resulting water is pumped to the | | | | now to what’s out there, it would still be |
| surface and processed through a reverse osmosis | | | | several years, upwards of five years, before |
| unit.” Anthony compared this to the | | | | production jumped from its existing rate to 10 to 20 |
| desalination of seawater. “The reverse | | | | million pounds at the most. |