Ballast coals

Because water and ash contents lower the overall value of a coal, the sum of these components has been referred to as ballast. For bituminous and anthracite 

ar as received, FO fixed carbon, HHV h her heating value, IL Illinois, KY Kentucky, NfD North Dakota, PA Pennsylvania, VM volatile matter, waf water and ash free, wf water free, WV West Virginia, W water/moisture, WY Wyoming. 

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The moving-bed gasifiers were the first systems available on industrial scale for pressurized gas generation from coal. Its robust and forgiving operation behavior as well as the acceptance of a broad fuel spectrum ranging from ballast coals (ash and moisture-rich) to caking coals of nearly all ranks. The development of a... 

The quick success of the technology mainly had two reasons (1) It was the first process to offer coal gas at pressures of 20-25 bar on industrial scale and (2) the economic utihzation of low-grade, ballast coals (see Section 3.S.5.2) was feasible for the first time. Hence, the Lurgi FBDB process remains the standard solution for gasification of ash-rich coals [189]. By the middle of the 1960s, around 100 units using the FBDB process have been installed worldwide. 

The zinc silicate, epoxy and coal tar/epoxy coatings are still used. Coal tar epoxies are used for crude oil tanks, sometimes on all the interior surfaces but more often for a) the bottom of the tank and about 2 m up the sides, b) the top of the tank and about 2 m down the sides, and (c) other horizontal surfaces where seawater ballast may lie. These partly coated tanks are frequently also fitted with cathodic protection to prevent corrosion of the uncoated areas when seawater ballast is carried. The pure epoxy or coal tar epoxy coatings applied in bulk cargo tanks used for the carriage of grain must be approved by the North of England Industrial Health Service, or by similar independent authorities in other countries. 

Molten ash is one of the products of combustion of coal in certain liigli-capacity boiler furnaces. It is also called slag. In some plants, the ash is removed from the furnace in this fluid form. Such furnaces are known as slag tap furnaces. Slag has some commercial value as ballast, coarse aggregate for concrete, road metal, etc. 

The world-wide knowledge in design, construction and operation of hydraulic pipeline systems based on experimental investigation and operational experiences as well as on theoretical calculations has shown the efficiency and prospect of the pipeline transport of coal in comparison with other kinds of transport. However, at a level of technical projects a series of weaknesses and/or imperfections in contemporary used systems of the coal pipelining with water used as a carrier liquid have been detected. One of them is a rather difficult, energy consuming and expensive process of dehydration of coal slurry before combustion. Besides, transport of a great quantity of ballast - the carrier water - also requires considerable power inputs and usually also expensive water treatment before reutilization or... 

A variety of human activities and products may contaminate estuaries with arsenic, including wood preservatives, pesticides, fertilizer manufacturing, mine drainage and wastes, coal utilization, runoff from slags used as road ballast, and arsenical paints from ships (Landrum, 1994 Davis, De Cumou and Eary, 1997), 370 (Pirrie et al., 2002 Mirlean et al., 2003). In some cases, specific arsenic sources cannot be identified (O Reilly Wiese, Bubb and Lester, 1995). Nevertheless, the cycling of arsenic between water and sediments in contaminated estuaries is often similar to cycles in pristine estuaries, open marine environments, and lakes. 

Use Building stone, metallurgy (flux), manufacture of lime, source of carbon dioxide, agriculture, road ballast, cement (Portland and natural), alkali manufacture, removal of sulfur dioxide from stack gases and sulfur from coal. 

Coal tar pitches are less readily available than they used to be their content of polynuclear aromatic hydrocarbons makes their safe use suspect. They have been replaced to some extent by the less effective petroleum bitumens whose mechanical properties are improved by combination with poly(vinyl chloride) and other chlorinated polymers as one-pack, nonconvertible coatings, or by combination with epoxy or polyurethanes in high-performance two-pack convertible coatings. Similar materials are preferred for coating ballast spaces and double bottoms in vessels, where economical systems are required that do not have to be attended throughout the lifetime of the vessel (15-25 years). Multiple coats with a total thickness of 250-400 pm are usually employed. 

Table 6.20 provides pilot plant data given by Cargill et al. [169], which served a basis of design for the Pinon Pine plant. The used fuel is a Southern Utah bituminous coal (SUT). The influence of the air dominates the gas composition. For example, the temperature-moderating effect of the nitrogen ballast can be... 

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