Canadian coals

The remainder of this paper can be restricted to coals of North America, since this is the area for which we have data and in any case other contributors to this collection will deal with the coals of their own areas. The first statement above needs qualification we ourselves have no liquefaction data on Canadian coals, but Ignasiak et al. (48) present some in this collection.Relying, as in the earlier part of this paper, on geological information, we can say that the strata of the North Great Plains and Rocky Mountain provinces continue north into Canada, as does the Pacific province. Nova Scotia contains some Carboniferous coals related to those in the Eastern province. 

Figure 7. Dependence of yields of hydrogenation products on the atomic hydro-gen-to-carbon ratio (a) Australian coals—noncatalytic conditions (10) (b) Canadian coals—catalytic conditions.

Studies on Noncatalytic Liquefaction of Western Canadian Coals... 

The great bulk of Canadian coal is concentrated in the three Western provinces (Saskatchewan, Alberta and British Columbia). 

A notable feature of the Western Canadian coals is their low sulphur content (usually <0.5%) which tends, however, to be partly offset by higher mineral matter contents than are associated with the Eastern coals. As well, bituminous coals in the mountain belts are typically deficient in vitrinite, which often represents less than 50% of the coal "substance" and only occasionally reaches 70-75%, but this is compensated by the fact that their micrinites and semifusinites tend to be "reactive" constituents when the coals are carbonized. Notwithstanding their low fluidity (rarely >1000 dd/min), Western mvb coals therefore make excellent metallurgical cokes when carbonized in suitably proportioned blends. 

Harris, J. O., Electrostatic beneficiation of eastern Canadian coals using a fluidized bed M. S. thesis, pp. 74-76, Univ. Western Ontario, London, Ont., Canada (1973)... 

Leeder, W.R. Gransden, J.R. Price, J.T. Botham, J.C. Prediction of Coke Quality with Special Reference to Canadian Coals, Proc. Ironmaking Conference (AIME), 1979, 38, 385. 

Even if current (per million btu) price differentials between coal and gas (or oil) do not widen much further, such direct substitution of coal for other hydrocarbon fuels is certain to become increasingly attractive - and may, indeed, prove imperative in the national interest. But in the long run equally important is that technological advances, coupled with the abundance and projected cost of Western Canadian coal, now make it possible to contemplate large-scale conversion of coal into gaseous and/or... 

Studies of fresh ash produced by coal combustion have shown that many trace elements (As, B, Bi, Cd, Cr, Cu, Ge, Hg, Mo, Pb, Ni, Se, Sr, Tl, V, W, Zn) are enriched in the fly ash compared to the bottom ash (Hansen Fisher 1980 Eary et al. 1990 Mukhopadhyay et al. 1996 Karayigit et al. 2001). For example, Mukhopadhyay et al. (1996) reported 10-20 times enrichment of most trace elements in the fly ash compared to the feed coal and association of As with crystalline Fe-0 and Fe-S phases in the bottom ash from a power plant in Nova Scotia fed by eastern Canadian coal. Elements enriched in fly ash are typically those more easily volatilized. Because fly ash particles also have smaller sizes and therefore greater reactivity than bottom ash, the probability of metal leaching is correspondingly greater. Ainsworth Rai (1987) and Rai et al. (1988) found that most of the Cu, Mo, Se, Sr, and V in fly ash was readily soluble. 

For a recent investigation into the nature of the sulphur in Canadian coal and coke, see Nioolls, Canada Dept. Mines Fuel Invest., 1926, 34. 

Goodarzi, F. and Swaine, D.J. (1993) Chalcophile elements in western Canadian coals. International Journal of Coal Geology, 24(1-4), 281-92. 

Goodarzi, F. (2006) Characteristics and composition of fly ash from Canadian coal-fired power plants. Fuel, 85(10-11), 1418-27. 

The high sulphur content of Eastern Canadian coals, as much as 8 , has led to studies aimed at reducing these sulphur levels (1). In general about two thirds of the sulphur is pyritic, often occuring as small inclusions, and therefore difficult to remove by conventional means. One method which holds promise is pyrolysis followed by magnetic separation. 

Research Reports on Eastern Canadian Coals (1979-1980), publ. 1981. 

Neither rates were influenced by the reaction locale, that is, by whether the reaction took place in the luminous discharge zone or some short distance from it (Fig. 12). However, unlike the HCN production rate, the CN rate generally tended to attain constant value after 1 h. In consequence, the (CN)2/HCN yield ratio increased slowly as reaction progressed. For a Canadian coal (88.3% C, 5.1% H) this ratio changed with temperature of the reactor, steadily decreasing up to 460 K and thereafter rising again (Fig. 13). The inset in Fig. 13 shows the manner in which... 

Fig. 13. Variation of (CN)2/HCN yield ratio with temperature for Canadian coal, as determined for 30 min reaction period. Shaded points for reaction in the luminous discharge zone open points downstream from the luminous zone. Inset shows variation of cumulative 2-h yields and (CN)2/HCN yield ratio with rank of Canadian coal. (Redrawn from Nishida, S., Berkowitz, N. Fuel 52, 262 (1973), by permission of Dr. Berkowitz and the publishers, IPC Business Press Ltd.)...

Goodarzi, F. D. J. Swaine, 1994. The influence of geological factors on the concentration of boron in Australian and Canadian coals. Chem. Geol. 118 301-318. 

FIGURE 24 Probable error Ep vs mean size of the treated coal for dense-media baths (DMB), dense-media cyclones (DMC), jigs, concentrating tables, and water-only cyclones (WOC). [After Mikhail, M. W, Picard, J. L., and Humeniuk, O. E. (1982). Performance evaluation of gravity separators in Canadian washeries. Paper presented at 2nd Technical Conference on Western Canadian Coals, Edmonton, June 3-5.]. 

Of the three maceral groups, vitrinite is more familiar as the brilliant black bands of coal. Vitrinite macerals are derived from the cell wall material (woody tissue) of plants, which are chemically composed of the polymers, cellulose and lignin. The vitrinite group is the most abundant group and typically makes up 50%-90% of most North American coals. However, most Gondwanaland coals and some western Canadian coals are vitrinite poor —the inertinite macerals dominate in these coals. 

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