Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content, and, since the 1880s, has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa, a coal mine and its structures are a colliery, a coal mine a pit, and the above-ground structures the pit head. In Australia, `colliery` generally refers to an underground coal mine. In the United States, `colliery` has been used to describe a coal mine operation but nowadays the word is not commonly used.
圖片編號:
128301544
拍攝者:
Sutowo
點數下載
授權類型 | 尺寸 | 像素 | 格式 | 點數 | |
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標準授權 | XS | 360 x 480 | JPG | 13 | |
標準授權 | S | 600 x 800 | JPG | 15 | |
標準授權 | M | 1499 x 2000 | JPG | 18 | |
標準授權 | L | 1936 x 2582 | JPG | 20 | |
標準授權 | XL | 2449 x 3266 | JPG | 22 | |
標準授權 | MAX | 5000 x 6667 | JPG | 23 | |
標準授權 | ADD | Vector | AI | 38 | |
標準授權 | TIFF | 7071 x 9429 | TIF | 39 | |
進階授權 | WEL | 5000 x 6667 | JPG | 88 | |
進階授權 | PEL | 5000 x 6667 | JPG | 88 | |
進階授權 | UEL | 5000 x 6667 | JPG | 88 |
XS
S
M
L
XL
MAX
ADD
TIFF
WEL
PEL
UEL
標準授權 | 360 x 480 px | JPG | 13 點 |
標準授權 | 600 x 800 px | JPG | 15 點 |
標準授權 | 1499 x 2000 px | JPG | 18 點 |
標準授權 | 1936 x 2582 px | JPG | 20 點 |
標準授權 | 2449 x 3266 px | JPG | 22 點 |
標準授權 | 5000 x 6667 px | JPG | 23 點 |
標準授權 | Vector px | AI | 38 點 |
標準授權 | 7071 x 9429 px | TIF | 39 點 |
進階授權 | 5000 x 6667 px | JPG | 88 點 |
進階授權 | 5000 x 6667 px | JPG | 88 點 |
進階授權 | 5000 x 6667 px | JPG | 88 點 |