It is often claimed that 8 million people died in the mines of Potosí, though this is generally regarded as an exaggeration. The historian David Stannard has also claimed that the average life expectancy of workers in Potosí or similar mines was three to four months. I was wondering if anyone has any more information on the conditions of these mines or could assess the accuracy of these claims?
/u/anthropology_nerd has an answer about working conditions in colonial silver mines from an AMA about slavery
Link to recent iteration of a broader answer about indigenous slavery in the Americas.