Mineral formation and Mining methods Flashcards
Valuable substances are concentrated within an igneous body (crystal fractionation, partial melting, and crystal settling)
Magmatic ore deposits
Concentration by hot aqueous
Hydrothermal ore deposits
Substances are concentrated by chemical precipitation from lake or sea water.
Sedimentary ore deposists
2 types of sedimentary deposits?
Evaporite deposits and iron formation
Concentration through gravity seperation
Placer ore deposits
Concentrated by chemical weathering
residual ore deposits
Evaporation of lake water or sea water results in the loss of water
Evaporite deposits
Iron rich and other iron bearing minerals deposited in basins with continental crust.
iron formation
Aided by flowing surface waters either in streams or along coastlines
Placer ore deposits
draining by rainwater percolation.
Leaching
During the process, the volume of the original rock is greatly reduced by leaching.
Placer ore deposits
extract ore minerals that are close to Earth’s surface
Surface mining
deep under the Earth’s surface
Underground mining
Addition of chemicals like cyanide or acid to dissolve the non-useful rock
Heap leaching
Addition of substance that produces air bubbles and attach to the valuable minerals to make them float.
Floatation
Heating the ore at very high temperature, causing the rock to separate into layer and extract the mineral.
Smelting
If the metal or mineral is magnetic, the crushed ore is separated from the waste materials using a powerful magnet
Magnetic seperation
Rocks that lie on top of the ore is blasted and loaded on trucks or carts.
Surface mining
Miners blast and dig tunnels and shafts into the rocks to reach the ore. Expensive and risky at the same time.
Underground
Used for low-grade gold ore where the crushed rock is placed on a “leach pile” where cyanide solution is sprayed or dripped on top of the pile.
Heap leaching
