Swell index

Free-swelling tests are commonly used to measure a coal s caking characteristics. A sample of coal is packed in a cmcible or tube, without compaction, and heated at a fixed rate to about 800°C. Infusible coals distill without changing appearance or state of agglomeration. The fusible coals soften, fuse, and usually sweU. The profile of the resultant coke is compared to a series of reference profiles so that a swelling index can be assigned. The profiles represent indexes between 0 and 9. The best cokes come from coals having indexes between 4 and 9. 

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). 

Physical Properties The free-swelling index (FSl) measures the tendency of a coal to swell when burned or gasified in fixed or fluidized beds. Coals with a high FSl (greater than 4) can usually be expected to cause difficulties in such beds. Detads of the test are given by the ASTM D 720 (American Society for Testing and Materials, op. cit.) and U.S. Bureau of Mines Report of Investigations 3989. 

The gel content (toluene insoluble per cent) of the rubber and the swelling index of the gel (the ratio of the volume of a swollen gel to its unswollen volume). The former is a measure of the amount of cross-linked material and the second a measure of the intensity of cross-linking. It has been found that a sample of medium gel content (5-20%) and a medium swelling index (10-20) gives the best impact strength in the blend. 

PVA has also been extensively used for immobilization of biocatalysts in a membranous form. As compared to PAAm, PVA is more hydrophilic and having adhesive property with better tensile strength in dry conditions. But it has high swelling index and dissolves readily in water when not cross-linked. PVA can be cross-linked using a variety of reagents including... 

Swell Index and Percent Solubles Measurements. Polymer films were cast on polyester film at 25X solids with various post additives. The films were air dried (16-48 h) then cured for 3 and 10 min at 150 C In a converted oven. Small samples (50-100 mg) of film were weighed, soaked In dimethylformamide (DHF) for 1 h, briefly pat-dried and reweighed In an A1 weighing pan. The samples were then redried at 150 C (20 torr) or 170 C, 1 atm for 30 min. 

Table I shows a comparison of free film swell Index results as a function of crosslinker at a constant comonomer level (0.3 moles/kg of polymer). ABDA and AEP gave crosslinking performance Identical to a conventional crosslinker, BNMA. However, derivatives which cannot cycllze, either because the amide has an additional substituent, as In 13, or the chain connecting the amide to the blocked aldehyde Is too short, as In 14, did not exhibit efficient crosslinking. They also showed significant discoloration, presumably due to Increased aldol condensation relative to 1, 2, or BNMA.

Butyl acrylate/0.3 moles/kg crosslinker copolymers In toluene. See Experimental for a definition of swell Index. 

Performance vs Crosslinker Level. Table IV presents tensile and swell Index results on a series of approximately 0 C Tg VAE emulsion copolymers. ABDA containing copolymers had fair swell Index values which deteriorated rapidly as ABDA levels declined, but showed slow declines In wet tensile performance with reduced levels. Possible reasons for this are discussed below. 

CrossUnker CrossUnker Moles oer kq Polvmer Tenslles Wet Drv (Pl1) PCE Swell Index... 

DILATATION AND FREE SWELLING INDEX RESULTS FOR ORIGINAL AND HYDROGENATED PHALEN SEAM COAL... 

Softening temperature Maximum contraction Maximum dilatation Free Swelling Index... 

Mixa no. CR (%) XNBR (%) Organoclay loading (phr) Swelling index Crosslinking density0 (mmol/100 g)... 

The free swelling index (FSI) was determined on each of the size fractions for the top samples the values ranged from 5% to 9, whereas the bottom size fractions ranged from 6% to 9 (see Table I). In each case the lowest values occur in the intermediate size fractions—namely, those ranging from 2X1% inch to % X Vfe inch. These show a rough relationship with the increase in fusinite and semifusinite and the decrease in vitrinite in these... 

In ordar to determine the effect of coal rank (at established by reflectance measurement of vitrinite in coal) on the reactions of coal as related to carbonization, gasification, combustion, and other processes, a wide range of bituminous coals were studied. The results show that reflectance measurements can be used effectively (1) to determine accurately yields of coal carbonization products such as coke, tar, gas, light oil, and liquor from pilot and commercial coke oven (2) to obtain the heating value and specific gravity properties of gases from these processes (3) to determine the free swelling index and B.t.u. content of coals ... 

In this paper, we demonstrate how mean maximum reflectance of vitrinite in oil (hereafter referred to as R ) can be used in place of conventional chemical-rank parameters (volatile matter and fixed carbon) to estimate the relative yields of carbonization products, specific properties of gas produced by carbonization, and chemical properties of coal such as calorific value and free swelling index (FS1). Further, we illustrate that measured R can be used to detect coal oxidation, to categorize coals for certain combustion uses, and to help classify coals by rank. 

Figure 3. Relationship between reflectance and free swelling index...

Other important chemical and physical tests performed to characterize coal include (I) Heating value (Btu content) (2) sulfur forms (31 ash fusibility temperatures (4) ash analysis (5) trace elements (6) free swelling index and (7) hardgrove grindability. 

Diene substrate latices were prepared by seeding techniques following the scheme shown in Figure 1. Persulfate anion was the initiator, and an alkyl aryl sulfonate was the emulsifier. Reaction time varied between 13 and 33 hours. Since all the substrates were prepared by similar techniques, the volumetric swell index and gel gravimetric data (toluene) varied little with particle size. Small differences in swell and gel characteristics should not be a variable in this study because of the polarity of the grafting monomer mixture and rapidity of the graft reactions. 

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

An approximate idea of the degree of swelling (the swelling index) experienced by a coal on carbonization may be obtained from the coke button left after the determination of volatile matter, but in many cases this measure of the swelling power is not sufficiently discriminating, principally because this is not the main function of the test. 

ASTM D-720. Standard Test Method for Free-Swelling Index of Coal. 

Free swelling index Measure of the increase in volume when a coal is heated without restriction... 

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