"Why do people protest coal mining and fracking, but not Lithium mining?"
Because it's not about the planet. It's about money and power.
The anti-coal/anti-fracking 'green' agenda is primarily a political weapon against right leaning industry. It's 'us versus them' and has very little (essentially nothing) to do with the environment.
If it was about the environment, they'd be as vehemently against lithium mining which damages the environment, electric cars (which depend on the electrical grid and coal and natural gas to power it) and the gas guzzling, pollution-dumping private jets they fly to their "save the planet" conferences.
Similarly, they would also be in support of 4th generation nuclear power, which no longer has the risks of melt-down, and uses its own waste for fuel, as opposed to polluting like old nuclear.
Never forget,
1) Everything in politics is about power and money, regardless of party. And,
2) 100% of politicians are lying, 100% of the time, regardless of party.
Remember those two things, you'll never be confused or manipulated by politics again, while others are manipulated to no end.