Mining Flashcards
What material is mined?
Metals - copper, iron, gold
Industrial minerals - salt, sulphur, phosphate
Construction materials - sand, gravel, gypsum
Energy minerals - coal, oil
What types of mines are there?
Opencast/strip mining
Open pit
Mountain top removal
underground
What is rock waste called?
Tailings
How are tailings produced and stored?
As a slurry in a pond secured by an impoundment
How is submarine tailings disposed of?
Into lakes, rivers, oceans
What is strip mining?
Mining a seam of mineral by first removing a long strip of overlying soil and rock. Most used for coal mining. Best when near surface
What is open pit mining?
Surface mining that extracts minerals from veins that are deepers
Mountain top removal mining?
Coal mining that explodes an “overburden” off the mountain. Mining waste is dumped into fulls in nearby valley
Mass restructuring of the earth to reach seams as deep as 120m
Underground Mining
Overlying rock is left in place and mineral is removed through shafts or tunnels
More expensive and dangerous than surface mining
Less overburden removed, fewer tailings result
Situ mining
Steam used to liquefy bitumen and pump it to the surface (95% of oil sands)
Environmental problems from mining
Habitat destruction
geomorphological impacts
pollution
water use
Habitat Destruction
Stripping of vegetation, soil overburden
Disposal of waste rock and tailings
Removes mountain ecosystem - waste dumped in valleys affects water systems
Geomorphological impacts
Slopes failures from steep cuts, removing strong rock to expose weak, blasting causes fractures, groundwater changes leading to pressure
Pollution
Heavy metals from tailings and smeltings - arsenic, lead, mercury, zinc
Acid mine drainage from sulphides that form sulphuric acid
How many tons of tailings are dumped in water systems each year?
180 million
