Argentinian lithium producer Orocobre (TSX: ORL) recently reported lower than expected lithium production in its third fiscal quarter because weather interfered with its evaporation rates of its lithium brines. This reveals two problems with lithium brine production: reliability and geography. Another source of lithium is rising to met these problems, hard rock lithium mining.
One analyst pointed out that Orocobre’s production problems “clearly demonstrate” that production is not a straightforward process. “Weather events are beyond the control of Orocobre, but this reaffirms that there is still room to improve on the robustness of operations and reduce production variability from weather impacts,” the analyst stated.
The company reported a 25-per-cent lower evaporation rate compared with the same quarter in 2017 which caused production problems and lithium output to fall 29 percent to 2,802 tonnes of Lithium Carbonate equivalent, from 3,937 tonnes in the December quarter. Its February rates were the lowest since 2011.
Weather has clear impacts on the production at lithium brine operations and with global demand for lithium on the rise, more reliable and consistent methods of production will be required. Lithium brine operations are limited to select climates and regions that can support sufficient weather to ensure economic processing.
Demand for the metal is set to grow by 600,000-800,000 tonnes of lithium carbonate equivalent over the next 10 years, Daniel Jimenez, senior commercial vice president at SQM, said.
The global lithium industry will need $10 billion to $12 billion of investment over the next decade to meet surging demand amid the electric vehicle boom, Daniel Jimenez of Chilean miner SQM said.
Not all lithium is equal and not all lithium is mined the same way. There are two significant sources of lithium, Lithium Brines and Lithium-Cesium Tantalum Pegmatites (hard rock).
According the United States Geological Survey’s 2018 Mineral Commodity Summaries, Australia was the largest producer of lithium. It produced 18,700 MT of lithium last year, up 3,300 MT from the previous year. The 34-percent increase has been attributed to two new spodumene operations that ramped up production to meet strong demand.
These production figures helped to push Australia as the top lithium producing country and it shows how hard rock lithium mines have the potential to disrupt traditional sources of lithium from older operators of lithium evaporation ponds.
Hard rock lithium deposits are not limited to select climates and regions and are going to help fill the demand as they are more evenly geographically distributed across the globe and are less dependant on a changing climate for production.
Hard Rock Mining
Rock minerals resources are way more homogeneously distributed on Earth with deposits located on each continent. But still, only a few sites are currently producing in Canada, Australia and China.
Lithium found in hard rock forms in crystals that are hosted in Pegmatites which form when mineral-rich magma intrudes into fissures in continental plates. As the last of this magma cools, water and other minerals become concentrated. These metal-enriched fluids catalyze rapid growth of the large crystals that distinguish pegmatites from other rocks. Pegmatites form thick seams called dykes that intrude into barren rock and can measure anywhere from a few to hundreds of meters.
Lithium-cesium-tantalum pegmatites account for about one-fourth of the world’s lithium production, most of the tantalum production, and all of the cesium production. Giant deposits include Tanco in Canada, Greenbushes in Australia, and Bikita in Zimbabwe. The largest lithium pegmatite in the United States, at King’s Mountain, North Carolina, is no longer being mined although large reserves of lithium remain.
Fig 2: Power Metals Corp Case Lake Main Dyke, PWM-17-33, boxes 1 to 4, 0.0 to 16.3 m. Note high grade lithium zone in boxes 2 and 3.
Hard rock lithium mining has few environmental risks that may hold up permitting. With big, stable crystals extracted through conventional means, lithium carbonate pegmatites provide a relatively “dry” and thus safe source of lithium. These pegmatites host a mineral called spodumene which contains the lithium.
Although miners sometimes encounter uranium, or beryl and fluorite, both known to be poisonous at high concentrations in drinking water, waste rock from lithium carbonate pegmatite mines differs little from ordinary rock and soil.
Concentrated ores across a narrow surface expression make pegmatite dikes. The high-quality lithium ore is processed into a range of lithium concentrates onsite. These concentrates can be easily packaged and shipped over large distances to market.
Hard rock lithium mining relies on traditional methods of drilling and processing, and presents a more reliable method of mining and opens up deposits closest to major markets within. Hard rock mining is giving countries a competitive advantage over countries dependant on lithium brines for production.
Attributes of Hard-Rock Lithium
Hard Rock has lesser environmental concerns
Hard rock lithium has strategic advantages in dynamic lithium markets compared to brine deposits. Extracting lithium concentrate from brine waters involves evaporation in large ponds in unique climates and geography, which may take over a year or more. Hard rock lithium, on the other hand, is easier to explore, mine and process using low-cost mining methods easily that are not ore specific.
Producing lithium from brines is a delicate and weather sensitive process as the majority of evaporation occurs in dry desert regions. The process depends on environmental factors that are beyond a company’s ability to control.
Furthermore, it involves tapping into water tables which would require extensive study and could impose disturbances on water uses.
Some scientists propose that the lithium-brine aquifers could be connected in some way with the other water sources. And if they are connected, it is possible freshwater will refill the remote spaces that are emptied by brine pumping, and that would reduce the water resources available for residents.
In August, the Argentinian mining secretary, fined Sales de Jujuy $1.4 million for changing, without permission, how it was drilling in the salt flat. A portion of the fine was also for spilling sewage on the white salt crust. Orocobre, the company that runs Sales de Jujuy, said it is contesting the fine and denied it broke any rules.
Soils and country rock surrounding a LCT pegmatite, as well as waste from mining operations, may be enriched in characteristic elements relative to global average soil and bedrock values. These elements may include lithium, cesium, tantalum, beryllium, boron, fluorine, phosphorus, manganese, gallium, rubidium, niobium, tin, and hafnium.
Among this suite of elements, however, the only ones that might present a concern for environmental health are beryllium and fluorine, which are included in the U.S. Environmental Protection Agency drinking-water regulations.
According to a 2010 US Geological Survey report, “neither lithium-cesium-tantalum pegmatites nor their parental granites are likely to cause serious environmental concerns.”
Lithium extraction from hard-rock minerals is more secure with good lithium grades, high recovery rates, and quick process durations that make it way more suited to any market change. However, the mining requirements and thermochemical processes involved are delicate and costly and require experts to realise the economical benefits of lithium extraction, for which there are only a few people in the world capable of doing. But still, only a few sites are currently producing in Canada, Australia and China. This presents a great opportunity for countries to develop their own sources of lithium and for investors of hard rock lithium explorers and developers.
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