Total moisture determination

The water in coal is bound in different forms to its constituents. It can be divided into three types (1) Free moisture, also referred to as external moisture, superficial moisture, or the primary moisture fraction, which is present in large cracks and capillaries. Water bound in this way retains its normal physical properties. (2) Inherent moisture, also referred to as internal moisture or the secondary moisture fraction, whose vapor pressure is lower, since it is absorbed within the pore structure of the coal. (3) Water of constitution, which is mainly combined with mineral matter normally present in coal. This water is generally driven off only at temperatures higher than those normally used for the determination of moisture content. Standard methods do not make use of these terms and define (1) the total moisture content of a coal and (2) the moisture content of the coal analysis sample. Total moisture determination must be made over the sample as received in the laboratory, in an air-proof recipient. The determination consists in drying in an oven at 105 °C till constant weight. Its value is of huge interest both in international and domestic coal trade (ISO 589, ASTM D3173). 

The best indirect, but seldom used, method is to determine the total moisture separately in a Penfteld tube, determine the loss on ignition in air at 825—875°C, and report graphitic carbon as percent loss on ignition (100 — %moisture — %ash). It is desirable to use a platinum dish for ignition loss and it... 

Moisture Holding Capacity. The bed or equihbrium moisture is the amount of moisture retained after equihbration at 96—97% rh at 30°C (D1412) (18). Total moisture is determined by air drying, cmshing to smaller particle sizes and heating at 107°C to constant weight (D3302). 

Total moisture content is determined on a separate 100 to 200g sample by distilling it in a 500ml flask with 200ml of dry CCU... 

Solution For lincomycin, we observe —20.7 pg more H20 than expected, independent of the sample size. Excess HzO comes from the atmosphere when the port is opened to add solid. To determine moisture in unknowns, subtract this blank from the total moisture titrated. This procedure can generate very reproducible data. 

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. 

Moisture in coal takes three forms (l)free or adherent moisture, essentially surface water (2) physically bound or inherent moisture (thai moisture held by vapor pressure and other physical processes) and (3) chemically bound water (water of hydration or combined" water). The ASTM defines total moisture as a loss in weight in an air atmosphere under rigidly controlled conditions of temperature, time, and air flow. Total moisture represents a measurement of all water not chemically combined. Total moisture is determined by a two-slep procedure, involving air-drying for removal of surface moisture from the gross sample, division and reduction of Ihc gross sample, and determination of residual moisture in the prepared sample. An algebraic calculation is used to obtain the total moisture value. 

Determine the total moisture content of the initial sample (unit au) in order to calculate the moisture retained, which is the total initial moisture minus the expressible moisture. 

Total moisture of coal Ultimate analysis of coal Ultimate analysis of coke Chlorine in coal and coke Phosphorus in coal and coke Arsenic in coal and coke Analysis of coal ash and coke ash Determination of moisture-holding capacity of hard coal General introduction and methods for reporting results Determination of total moisture of coke Proximate analysis, determination of moisture content of the general analysis test sample... 

The total moisture in coal is the determination of the moisture (in all forms except water of crystallization of the mineral matter) that resides within the coal matrix. In fact, moisture (or water) is the most elusive constituent of coal to be measured in the laboratory. The moisture in coal ranges from 2 to 15% by weight in bituminous coal to nearly 45% by weight in lignite. 

The role of water in coal and the quantitative measurement of water are complicated because water is present within the coal matrix in more than one form (Allardice and Evans, 1978). Thus, the total moisture includes both the surface moisture and the residual moisture remaining in the sample after determining the air-dry loss (ASTM D-3302). Thus,... 

To determine the total moisture, either an analysis sample can be prepared from the moisture sample, or the regular analysis sample can be used for this purpose, provided that the moisture analysis is performed on the analysis sample within a prescribed time after the air-dry sample is prepared. When separate analysis samples are used for moisture and for the other determinations that are... 

Methods for determination of the total moisture in coal have been placed into the following categories (1) thermal methods that often include distillation methods (2) a desiccator method (3) distillation methods, which often include extraction and/or solution methods (5) chemical methods and (6) electrical methods. 

Inherent or equilibrium moisture is used for calculating moist, mineral-matter-free calorific values for the rank classification of high-volatile bituminous coals. It is also used for estimating free or surface moisture, since total moisture is equal to the sum of the inherent moisture and the free moisture and is considered the inherent moisture of the coal as it occurs in the unexposed seam, where the relative humidity is probably near 100%. However, due to physical limitations, equilibrium moisture determinations are made at 96 to 97% relative humidity and used as inherent moisture values. 

Moisture total moisture content of a sample customarily determined by adding the moisture loss obtained when air drying the sample and the measured moisture content of the dried sample. Moisture does not represent all of the water present in coal, as water of decomposition (combined water) and hydration are not given off under standardized test conditions. 

Total moisture all of the moisture in and on a consignment or sample of coal commonly determined by quantitatively air drying a sample and then assaying residual moisture in the air-dried sample thus, total moisture is the sum of the air-dry loss and the residual moisture adjusted to an as-received basis (ASTM D-2961 ASTM D-3302). 

Some of the traditional methods used for the characterization of bar soaps are moisture, free acid or free alkalinity, total soap, and chloride (salt). Moisture determinations are typically run by Karl Fischer titration. However, under certain circumstances, moisture can be measured gravimetric ally. The measure of free fatty acid or free alkalinity is typically done via a simple pH titration using phenophtha-lein or potentiometric end point. Total soap is generally done using an extraction/ gravimetric procedure the soap sample is acidified in an ethanol-water mixture, the fatty acids are extracted into a hydrocarbon solvent, and the amount of extracted... 

Fifteen grams of fi-esh fermented soya oil eake from each layer is dried during 48 h at 105 °C until a stable weight is obtained. Moisture content is determined by the difference between the fresh matter and the dried mater. Then, the percentage of the ratio moisture content/fresh matter of the fermented soya oil cake during the process is determined by layer. Each test is done in triplicate. To determine the total moisture content of the fermented soya oil cake during each experiment, moisture contents of the fours layers are added, and the average value is evaluated. The variation between tests values are less than 8.0%. 

Low-latitude planktonic foraminiferal d O records are good proxies for tropical sea surface temperatures. Tropical temperatures are an important component of the climate system because they influence evaporation, and hence, total moisture in the atmosphere. Planktonic and benthic foraminiferal comparison allows one to assess equator-to-pole as well as vertical temperature gradients during the Cenozoic, and thus, to determine planetary temperature changes. Finally, much of the climatic change in the last 65 million years has been ascribed... 

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