Swelling number

Eor the free swelling index which is also known as the cmcible swelling number (ASTM D720), a coal sample is rapidly heated to 820°C in a covered cmcible. Then the profile of the resulting char is compared to a series of standard numbered profiles (18). Eor the Roga index weighed amounts of coal and standard anthracite are mixed and carbonized, and the product coke is tested in a Roga dmm for its resistance to abrasion (89). 

The high-volatile Liddell bituminous coal (Figure 2 (E)) shows little indication of thermally-activated molecular mobility below 500 K. There is some fusion between 500 and 600 K followed by a major fusion transition above 600 K which appears very similar to the high temperature transition of the Amberley coal. This Liddell coal, however, has only 6% liptinite, has a crucible swelling number of 6.5 and exhibits considerable Gieseler fluidity. We therefore attribute this high temperature fusion event to the aromatic-rich macerals of the coal and associate it with the thermoplastic phenomenon. This implies that a stage has been reached in the coalification processes at which aromatic-rich material becomes fusible. 

Free-Swelling Index (Crucible Swelling Number) Roga Index Dilatometer Gray- King... 

The classes of coal are subdivided into groups according to their coking properties, as reflected in the behavior of coals when heated rapidly. A broad correlation exists between the crucible swelling number and the Roga index (ISO methods), and either of these may be used to determine the group number of a coal. 

The marketing challenges, posed in the 70 s, will require additional shifts of emphasis (see Figure 2). The many established products that will appear will face a swelling number of complexities. Higher quality analyses and evaluations in the early program stages and more effective and intense sales development efforts will be required. 

The swelling number represents the ratio between the volume of 5 g of bentonite powder and the volume occupied by 5 g of bentonite left in 100 ml water for 24 hours. Various forms of bentonite behave differently (Table 10.7) and swelling is also affected by the type of water, especially in the case of sodium bentonite (Maujean, 1993). The and Mg + cations in tap water take the place of the smaller Na" and K+ cations in the bentonites, thus increasing the swelling number. This phenomenon is not observed in calcium bentonite, where, on the contrary, the swelling volume decreases. 

The only small-scale methods that have stood the test of time and have been accepted as standard plasticity tests are the crucible swelling number, Gray-King coke type, dilatation characteristics, Gieseler plasticity, and, in some countries, the Rogas index. All of these are essentially empirical in nature and many are subjective, at least to some degree. 

The FSI or crucible swelling number (CSN), which is a measure of the ino-ease in volume of the coal when it is heated in the absence of air. This test is also used to characterize coals for combustion. The FSI is at least in part a rank-dependent parameter but also depends on the maceral composition of the coal, the vitrinite maceral group being the main contributor to the swelling properties. 

BSI. 2011. EN-analysis and testing of coal and coke. Part 107 Caking and swelling properties of coal. Section 107.1 Determination of crucible swelling number (BSI BS 1016-107.1). British Standards Institution, London, U.K. 

ISO. 2011b. Coal—Determination of Crucible Swelling Number (ISO 501). International Standards Organization, Geneva, Switzerland. 

A mixed Pt-Rh cluster of corpulent proportions [Pt4Rhjg(CO)35] - has been reported by Fumagalli et aJ . The same groups is responsible for some Re-Ir clusters via addition of tIr(CO)4l" to fRe2(p-H)2(CO)g], and new Mi-Bi clusters . Adams has contributed to the swelling numbers of mixed-metal cluster compounds with RugPt 2 (CO) 23(11 -11)2 and other Ru-Pt clusters . A number of osmium-Group VI metal cluster compounds have also been prepared . 

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