Short answers, pulled from the story.
Mining is the extraction of geological materials and minerals from the surface of the Earth. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. In a wider sense, mining also covers non-renewable resources such as petroleum, natural gas, and even water.
The oldest known mine in the archaeological record is the Ngwenya Mine in Eswatini, which radiocarbon dating indicates is about 41,000 to 43,000 years old. At that site, Paleolithic humans mined hematite to make the red pigment ochre.
The Romans developed large-scale methods using water brought to the minehead by aqueducts. They used hushing to wash away overburden, fire-setting to crack rock, and sluicing for alluvial gold, as at Las Medulas in Spain where seven long aqueducts tapped local rivers. At Rio Tinto a sequence of 16 reverse overshot water-wheels lifted water about 24 meters.
Surface mining removes vegetation, dirt, and bedrock to reach buried deposits and includes open-pit mining, quarrying, strip mining, and mountaintop removal. Underground or subsurface mining digs tunnels or shafts to reach deeper ore, using methods such as drift, slope, shaft, and room and pillar mining. Modern surface mining produces 85 percent of minerals in the United States and 98 percent of metallic ores.
The Courrieres mine disaster killed 1,099 miners in Northern France on the 10th of March 1906, making it Europe's worst mining accident. It was surpassed only by the Benxihu Colliery accident in China on the 26th of April 1942, which killed 1,549 miners.
Cobalt mining in the Democratic Republic of Congo has been linked to child labor, hazardous conditions, and wages of about two dollars a day. Researcher Siddharth Kara has documented wall collapses, clinics without antibiotics or x-ray machines, and displaced families forced to send children to dig. In December 2019-14 Congolese families filed a lawsuit against the mining company Glencore.
Ore mills generate large amounts of waste called tailings. About 99 tons of waste is generated per ton of copper, and because only 5.3 grams of gold are extracted per ton of ore, a ton of gold produces 200,000 tons of tailings. These tailings can be toxic and are most commonly dumped into ponds secured by impoundments.