The Environmental Impact of Spodumene Mining

The mining and refining process of spodumene to produce lithium goes through different stages, each with their own environmental hazards:

• • Mining
  • Benefication
  • Roasting
  • High Temperature Leaching
  • Purification
  • Final Purification & Product Production

Mining

Spodumene mining utilizes the traditional mining techniques most people think of: digging and drilling the Earth for rock. Large equipment (which produce greenhouse gasses) is needed to conduct the rock blasting and ore extraction necessary.

The extracted ore is graded and crushed to ensure a constant feed concentration for the following steps of the operation.

This conventional mining method produces the wastes that are associated with open pit mines, potentially releasing toxic chemicals into the environment.

Benefication

The next step is to concentrate spodumene, known as beneficiation. In low grade operations, the ore will be ground in a ball mill and processed through a multi-stage counter-current flotation process.

Here, the gangue (commercially worthless part of the ore) is separated from the spodumene mineral, and the gangue ends up flowing into a tailings pond which is another problematic area of spodumene mining, albeit necessary.

Most modern industrial countries require that ponds be lined with materials that are high strength polymers designed to minimize mine water and waste movement into local soils or ground water, however, there is a saying that 'all ponds leak' which unfortunately rings true, resulting in a contamination of local ground water with chemical wastes.

Roasting

The spodumene moves to a dryer and kiln that operate at about 1,000°C. This process converts the mineral into an easy-to-extract form using acid.

This stage in the process also has the potential to release chemicals in the environment, some of which can be attributed to the fuel quality, calciner design, and emission abatement steps.

High Temperature Leaching

Normally, the hot ore is leached with sulphuric acid at about 250°C. Approximately 60-80% of lithium can be solubilized in this step.

This stage produces the same environmental pollutants as the roasting process (see above).

Purification

The lithium is treated with lime to neutralize the excess sulphuric acid and produce gypsum. The waste from this process may end up in a tailings pond or it could be isolated by local regulators for separate ponds as required by law.

Further processing is done to remove other metal impurities such as calcium, magnesium, iron and so on.

This process typically utilizes ion exchange or solvent extraction techniques which produce waste streams containing various chemicals including salts and solvents from the solvent extractant circuit.

Each step of this process produces some sort of waste which also adds another expense to the process. Many times, businesses find financial value in releasing from the premises rather than handling it themselves.

These wastes cannot simply vanish into thin air, so they will likely end up in a tailings or wastewater pond. 

Final Purification & Product Production

The purified lithium sulphate can then be converted to either lithium carbonate or hydroxide by adding soda ash. At this stage, sodium sulfate and gypsum are also produced as wastes that usually end up in a pond.

In order to meet 'battery grade' standards, more purification may be necessary. Any waste produced from these purification measures ultimately end up in waste ponds or lagoons.

Likewise, the filtration system's wastewater will also end up in a waste pond, but wastewater could also potentially be purified and recycled.

The Future of Lithium Mining Technology 

Each step of the spodumene refinement process produces significant amounts of greenhouse gasses and requires and lot of energy consumption.

As the lithium industry grows, it's important to be mindful that this expansion will have an impact on both our environment and economy.

While this article focuses on spodumene mining in particular, but the same attention and environmental focus should be applied to the entire lithium extraction industry.

If you're interested in learning about sustainable lithium mining or how to invest in the lithium market, we'd love to continue the conversation!

Beyond Mining

Lithium has been making huge waves in other industries, from the oil & gas industry to the transportation industry.

Even in the world of cryptocurrency (with the rise of LITH Token), lithium offers a method to completely revolutionize how businesses and people power their digital technology with heavy consideration regarding the environmental impact of lithium mining.

Connect with us and see how we can shape the future of the lithium mining industry and our future of clean energy!