Determination volatile matter

For synthetic rubbers, the mill homogenization is generally omitted, although it is specified as an alternative where the appropriate evaluation procedure requires it before measuring Mooney viscosity. Different conditions are given for specific polymers. The mill method of ISO 248 for determining volatile matter is specified but the oven method may be substituted if the material sticks to the mill rolls. Regardless of which volatile matter method is used, the mill procedure is required to dry samples for any chemical tests needed - unless this is not possible. To the uninitiated at least, this is not a model of clarity. Vulcanization characteristics are determined for synthetic rubbers, but not plasticity retention index. 

Determination of the volatile matter content of coal (ASTM D-3175 ISO 562) is an important determination because volatile matter data are an integral part of coal classification systems (Chapter 1) and form the basis of evaluating coals for their suitability for combustion and carbonization. The methods for determining volatile matter content are based on the same principle and consist of heating a weighed sample of coal (usually about 1 g) in a covered crucible to a... 

Analysis. The proximate analysis is based on determinations of volatile matter, moisture, and ash for a coal sample. Fixed carbon is then calculated by difference. Volatile matter is determined empirically by measuring the weight loss when coal is heated in a covered cmcible at either 950°C (ASTM D3175 or D5142) or 900°C (BS). 

Simkins J. Squire, The Rapid Determination of Volatile Matter by the Mytron FAB-1 Moisture Meter , Explosive Research Development Establishment TN 82 (1973) 56) Anon, Ex-... 

Table 3 shows some physicochemical properties used as international GA quality parameters, for example moisture, total ash content, volatile matter and internal energy, with reference to gums taken from Acacia Senegal species in Sudan (FAO, 1990, Larson Bromley, 1991). The physicochemical properties of GA may vary depending on the origin and age of trees, the exudation time, the storage type, and climate. The moisture content facilitates the solubility of GA carbohydrate hydrophilic and hydrophobic proteins. The total ash content is used to determine the critical levels of foreign matter, insoluble matter in... 

The composition of coal is conveyed by representing its proximate and ultimate analysis. The former implies determination of contents of moisture, volatile matter, fixed carbon, and ash, while the latter implies total carbon, hydrogen, oxygen, nitrogen, sulfur and ash. Here, an account will be provided of the constituents of coal, moisture, volatile matter, ash, fixed carbon, and some miscellaneous components. 

The raw data in the more comprehensive study (61) were conversions, determined in duplicate, when each of 104 coals selected from three geological provinces was heated with tetralin under standard conditions, together with the results of 14 commonly made analytical determinations for each coal. An early observation in this study was that when data for all 104 samples were plotted against volatile matter, a steady decrease of conversion with decreasing volatile matter was apparent. But there was a great deal of scatter (r=0.85). In any case, the formal requirements that make possible the employment of valid statistical analyses were not met by the data matrix, as evidenced by skewed and bimodal relationships between the variables the sample set was heterogeneous. ... 

The chemical and petrographic properties of the twenty coals used in the hydrogenation experiments are shown in Tables II and III. Mineral matter was determined directly using a radio frequency low temperature plasma asher at medium power rating for approximately 48 h per coal. The volatile matter was corrected for the effects of the mineral matter by applying the equation used by Given et al (5). 

The characteristics of coals that determine classification and suitability for given applications are the proportions of volatile matter, fixed carbon, moisture, sulfur, and ash. 

Methods have been described for the determination of total fatty acids in raw sewage sludge. These methods [30-32] require a concentration steps such as simple distillation, steam distillation, evaporation, or extraction [33-35] which resulted in great losses of the volatile matter [36, 37],... 

In the United Kingdom, standard quality testing before using gunpowder includes a determination of the volatile matter (which is mainly moisture) by oven drying under controlled conditions. As a general guide, the moisture level determined in this way would be expected to fall between 0.5 and 1.4% for an acceptable powder. 

Coal is a rich source of carbon and has been a valuable source of fuel for centuries. It is classified by both coal type and coal rank. Coal type is determined by the nature of the original biomass that led to the formation of the coal. Coal rank signifies the degree of maturation or chemical change in coal and usually determines coal quality. The calorific value, moisture content, elemental analysis, volatile matter, ash, and fixed carbon content are important qualities of coal. 

Graphite is frequently, although incorrectly, analyzed by the proximate method used for coal in which the volatile material is determined by strongly heating the sample in a covered or luted cmcible. Some oxidation of the graphite always occurs so that the value obtained for volatile matter is high and thus the "fixed carbon" is too low. The method lacks both accuracy and precision. 

This acid should respond to the tests for non-volatile matter, hydrochloric acid, sulphuric, acid, heavy metals, and quantitative determinations, as described under Acid Acetic 00.5 per cent. Its strength, however, is loss. The following tost also applies. 

It is, however, known that the fa values from Equation 1 must be regarded as being too low because not only the aliphatic part but also small aromatic systems are split off during determination of the volatile matter (II). Furthermore, these fa values make sense only as long as the %V is not too high. This method is, therefore, limited to the vitrinite (/- = 0.75) and micrinite (fa = 0.87). 

The magnitude of expansion also depends on particle size as shown in Figure 14. Expansion decreases with decreasing particle size, varying in extent with coal rank. This effect is to be expected because it is determined not by the gas released per unit time, but only by the magnitude of the internal pressure in the sample briquet, which is lower for a small initial particle size than it is for a coarse sample. This in turn indicates that contrary to what the micrograph shows, the inter-particle bond cannot be without voids absolutely after contraction has occurred since this would mean that the dilatation depends on particle size. Figure 15 shows the relationship between rank and particle-size dependence in the dilatometer carbonizations the volatile matter is represented on the abscissa. 

Measurement of Volatile Matter Release Rates. Volatile matter release rates from anthracite were determined by using the apparatus shown diagram-matically in Figure 1. The power input to the 1-kw., 20-volt Hoskins tube furnace and transformer was controlled by means of a Leeds Northrup durationadjusting type program controller which permitted linear heating rates up to 20°C. per min. to be selected with varying soak times and temperatures. A maximum temperature of 1000°C. was used since this was the maximum temperature at which the furnace could be operated continuously. The temperature of the furnace was measured by a chromel-alumel thermocouple inside a... 

These coke samples were studied by chemical, x-ray diffraction, and microscopic techniques. Chemical data include total carbon, volatile matter, ash, and sulfur determinations. 

Proximate Analysis. This includes (he determination of total moisture, volatile matter, and ash and the calculation of fixed carbon for coals and cokes. The term Proximate" should not be confused with Ihe word approximate." since all Proximate Analysis tests are performed according lo rigid specifications and tolerances. Proximate Analysis results may be used lo establish the rank of coals to show the ratio of combuslible lo incombustible constituents, lo provide the basis for buying and selling coal, and to evaluate for beneliciation, or other purposes. 

There appears really to be no method by which true external moisture may be determined, that is, no method by which only the surface moisture is removed in such fashion that the residual solvent in the powder is found to be the same both before and after the powder has been allowed to take up moisture. Samples of powder were taken and residual solvent was determined by the several methods indicated in the next table. The samples were exposed 2 weeks to an atmosphere practically saturated with water vapor, and residual solvent was again determined as before. The surprising result was secured in every case, as indicated, that the amount of residual solvent was less after the powder had been exposed to the moist atmosphere than it was before it had been exposed. Yet the powder had taken up large quantities of moisture during the exposure. It is clear that the exposure to the moist atmosphere had made the volatile matter of the interior of the grains more accessible to desiccating influ-... 

Proximate analysis Determination of the approximate overall composition (i.e., moisture, volatile matter, ash, and fixed carbon content)... 

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