The underlying problem is an excess of manual labor in Africa, caused by excessive birth rates. Take fertility rates down to sub-replacement like they are in the rest of the world, and mining will just be automated.
Never mind the perpetual political destabilization of that region because our oligarch owned nations want the natural treasures buried beneath that African soil for cheap. It's their own fault for having babies. Djeez.
As long as the poor guy can choose to work something better wages and working conditions will reflect this (or the mine will shut down). See Europe after the black death.
In what fucking world holy shit. Good lord, seriously. Labor IS PEOPLE. There is no such thing as an excess person.
The underlying problem is an economic system that allows/depends on the exploitation of vulnerable and precarious labor. If you're going to justify this then grow a spine and do it, don't deflect it back on the people being hurt the most saying they should cull themselves for our moral convenience.
Just that there might not be enough resources to meet the needs of population. Such as food and water. Thus purchasers of labour will get away by providing minimum. If there weren't such big excess supply they would need to provide more or provide better conditions.