Bulk resources Flashcards
1
Q
Ball Clay Geology
A
- Devonian and Carboniferous marine sandstones and mudstones.
- Altered to slates etc. during Variscan orogeny
- Carboniferous granites intruded during Variscan orogeny
- deep weathering of slates and granite during the tertiary
2
Q
Ball Clay Formation
A
- deep tropical weathering of:
- clays in the slates (illite and chlorite to disordered kaolinite)
- feldspars in the granite
3
Q
Ball Clay processing
A
- clay is shredded to homogenise
- 220,000 tons exported annually
- clay can be processed
- deflocculant added
- large particles removed by screening
- mixed with carbonaceous clay
- fired to produce sanitary ware
4
Q
Ball Clay products
A
- bathroom ceramics
- sink, toilet, shower
5
Q
Brick Clay
A
- plastic mixed with water
- have enough tensile strength so keeps shape
- clay particles must fuse together
- Illite and Kaolinite (both non-expanding)
6
Q
sands and Gravels
A
- essential in concrete production
- snads used in mortar and small amounts in brick production
- river Kennet valley gravels (mostly flints eroded from the chalk)
7
Q
Cement
A
- basic ingredient of concrete
- limestone, shells, chalk and marl (calcium carbonate rich mud)
- mixed with shale, clay, blast furnace slag, sand
- crushed rock and other ingredients heater in a kiln to 1500oC
- forms marble sized balls
- crushed to a fine powder
8
Q
Environmental impacts
A
- dust, gases and noise in quarries (risk ot workers, silicosis etc.)
- cement is very caustic
- local resistance to new extractive activities
- remediation of old quarry and pits (landfill, recreation - marinas, rowing lakes, fishing etc., wildlife reserve)
9
Q
Greenhouse Gas Emissions
A
- Cement Production = CO2 emissions
- decarbonation of limestone
- kiln fuel combustion
- vehicles in quarries, cement plants and distribution
- 5% of global CO2 emissions
- 17% of landfill worldwide is concrete by product.
10
Q
ball clay formation
A
Ball clays are sedimentary in origin.
Ancient rivers and streams washed kaolinite (formed from decomposed granite) from its parent rock.
As the streams flowed from upland area they mixed with other clay minerals, sands, gravels and vegetation before settling in low-lying basins to form overlaying seams of ball clay.
