Lithium Slag: Hidden Dangers in Our Quest for Green Energy
Lithium-ion batteries are powering our green energy future, but there's a hidden cost.
The Problem with Lithium Slag
Every year, China alone produces over 10 million tons of lithium slag (LS) from smelting lithium mica. While we focus on extracting lithium, we're ignoring the environmental risks posed by other harmful substances in the slag.
Research Findings
Researchers studied LS from 20 different companies. They found high levels of:
- Beryllium (Be)
- Manganese (Mn)
- Tin (Sn)
- Zinc (Zn)
- Thallium (Tl)
The type of lithium mica used (zinnwaldite or lepidolite) also affected how much arsenic (As) and cadmium (Cd) ended up in the slag.
Behavior of Harmful Substances
The way these harmful substances behave depends on the environment. They can be more or less mobile in different conditions:
- Gastric fluid - Most mobile
- Acetic acid
- DTPA
- Water - Least mobile
Key Concerns
- Beryllium (Be) and Thallium (Tl) are particularly concerning.
- Their behavior changes based on how the lithium is smelted.
- Adding Na2SO4 creates a mineral called lazurite, which makes Be more mobile.
- Too much CaSO4 stops the formation of leucite and nepheline, which makes Tl more likely to leak into water and DTPA.
The Need for Better Regulations
This research highlights the need for better regulations and safer smelting processes. As we push for more lithium to support our green energy goals, we must also consider the environmental impact of the byproducts.
