Why have most companies started to extract lithium from brine water rather than mineral ore?

The process is less expensive.
The quality of lithium is higher.
The process is less time consuming.
The ore deposits have been depleted.

The correct answer is "The process is less expensive."

Extracting lithium from brine water is now widely used because it is more cost-effective than extracting it from mineral ores. This is because the process of extracting lithium from ores involves several steps, including roasting and leaching, which require a lot of energy, time and resources. On the other hand, the process of extracting lithium from brine water involves pumping the water into evaporation ponds, which evaporate the water leaving concentrated lithium behind. This process is less time consuming and requires less energy, hence it is more economical.