一個名字，幾個品種并非所有的煤都是一樣的。事實上，煤是由這樣一種復雜的混合物組成的，它可能在不同的礦床中有很大的不同。一些被稱為冶金煤或煉焦煤的煤炭礦床是煉鋼所必需的。其他被稱為熱煤或蒸汽煤的沉積物被用來發(fā)電和制造水泥。煤炭礦床的差異來自形成礦床的原始植物材料和產生煤炭的過程的差異。不同植被類型和礦物含量的變化影響煤的組成。更高的壓力和溫度也影響了礦床的質量，以及形成時間的長短。碳含量越高，排名越高在北美，煤是按等級分類的。等級較高的煤含有更多的碳，產生更多的能源。無煙煤*是排名最高的煤，因為它的含碳量最高，因此它的熱值最高。無煙煤也是所有煤中最堅硬的。盡管目前加拿大還沒有開采無煙煤，但在不列顛哥倫比亞省西北部的偏遠地區(qū)已經發(fā)現(xiàn)了無煙煤礦床。煙煤是無煙煤的一種。它的碳含量高，通常含水量低，并且含有少量的氫和氧。這種成分使煙煤成為冶金和熱力方面的理想材料。2001年，煙煤占加拿大煤炭總產量的48%以上。其中84%用于冶金用途。加拿大不列顛哥倫比亞省、阿爾伯塔省和大西洋省有煙煤礦床，育空省、西北地區(qū)和努納武特省有少量煙煤礦床。次煙煤*煤的等級較低，比煙煤更軟，含水率較高。它非常適合用于火力發(fā)電廠。2001年，亞煙煤的產量占加拿大總產量的35%。褐煤*是所有煤中排名最低的。與其他煤相比，褐煤比較軟。它的顏色從深黑色到各種深淺不一的棕色。位于薩斯喀徹溫省南部和阿爾伯塔省東南部的褐煤為薩斯喀徹溫省提供了65%的電力。

ONE NAME, SEVERAL VARIETIES 

All coal is not created equal. In fact, coal is composed of such a complex mixture of materials, it can be quite different from one deposit to another. Some deposits of coal, called metallurgical* or coking coal, are essential for use in steelmaking. Other deposits, called thermal* or steam coal, are used to generate electrical power and make cement.
Differences in coal deposits came from variations in the original plant materials that formed the deposit and in the process that creates coal. Different kinds of vegetation and variations in the amount of minerals influenced the composition of coal. Higher pressures and temperatures also affected the coal deposit’s quality, as did the length of time it spent being formed.

THE HIGHER THE CARBON CONTENT, THE HIGHER THE RANK 

In North America, coal is classified by rank. Higher ranked coal contains more carbon and produces more energy.
ANTHRACITE* is the top-ranked coal because it has the highest carbon content and, therefore, the most heat value.  Anthracite is also the hardest of all coals.  Although it is not currently being mined in Canada, anthracite deposits have been found in remote areas of northwestern British Columbia.
BITUMINOUS* coal is a step down from anthracite. It has a high carbon content, is generally low in moisture and has small amounts of hydrogen and oxygen. This composition makes bituminous coal ideal for both metallurgical and thermal uses. In 2001, bituminous coal accounted for over 48 per cent of Canada’s total coal production. Of that, 84 per cent was mined for metallurgical use. There are bituminous coal deposits in British Columbia,  Alberta and Atlantic Canada and minor amounts in Yukon, Northwest Territories and Nunavut.
SUB-BITUMINOUS* coal is lower ranked and softer than bituminous coal and tends to have high moisture content. It is well suited for use in thermal electric power generation plants. Mined in Alberta, sub-bituminous coal accounted for 35 per cent of Canada’s production in 2001.
LIGNITE* is the lowest ranked of all the coals. In comparison to other coals, lignite is quite soft. Its colour can range from a dark black to various shades of brown. Found in southern Saskatchewan and southeastern Alberta, lignite generates 65 per cent of Saskatchewan’s electric power.