Mineral impurity

In addition to the main acidulation reaction, other reactions also occur. Free calcium carbonate in the rock reacts with the acid to produce additional by-product calcium compounds and CO2 gas which causes foaming. Other mineral impurities, eg, Fe, Al, Mg, U, and organic matter, dissolve, the result being that the wet-process acid is highly impure. 

In addition to carbon, all coals contains many noncombustible mineral impurities. The residue from these minerals after coal has been burned is called ash. Average ash content of the entire thickness of a coal seam typically ranges from 2 to 3 percent, even for very pure bituminous coals, and 10 percent or... 

Conductivity, the electrical conductivity of the water measured in microSiemen/cm is the traditional indicator for mineral impurities. Resistivity, the reciprocal of conductivity, measured in Megohm-cm. It is used in some industries instead of conductivity particularly for ultra-pure water. 

Almost all larger FT and HP boiler plants employ some form of external capital equipment for MU water and FW treatment. The rationale for installing capital equipment is to eliminate (or at least minimize) the level of mineral impurities, process contaminants, and noncondensable gases entering the boiler via the FW system to reduce the potential for the development of waterside deposition, corrosion, steam contamination, and other waterside problems. 

Summation of the results of the determinations of water, organic solvents, mineral impurities and the organic components amounts to loo %. The results of methods employed to analyze the substance other than these given above are not used for the calibration of the assigned value but are reported to support the results obtained by the defining methods. For most reference substances intended as assay standards the assigned content is normally expressed as is so that it is essential (when establishing the CRS) to determine the content of water and residual solvents for a non-specific assay and also, for a selective assay, to determine the content of impurities. 

XPD [18]. Similarly, mineral impurities in talc were analyzed by polarizing light microscopy, differential thermal analysis, and XPD [19]. It must be recognized, however, that small amounts of crystalline impurities (usually <0.5% w/w) may not be detected by XPD. In case of noncrystalline impurities, mrch higher concentrations may be nondetectable. 

Raask, E., Mineral Impurities In Coal Combustion, Hemisphere Publishing Corp., New York 1985. 

Consult your owner s manual to ensure that any air eliminators are used properly. Generally, the procedure is to close tightly all drain openings, pour in engine coolant concentrate, then fill with water of good quality to the proper level. Also, fill the coolant recovery system reservoir to the proper level with properly diluted engine coolant (see Fig. 6). (Avoid use of water containing excessive amounts of minerals, impurities, or suspended matter.)... 

Minerals such as euxenite, fergusonite, samarskite, polycrase and loparite are highly refractory and complex in nature. These minerals may be opened up by treatment with hydrofluoric acid. While metals such as niobium, tantalum and titanium form soluble fluorides, rare earth elements form an insoluble residue of their fluorides. Such insoluble fluorides are filtered out of solution and digested with hot concentrated sulfuric acid. The rare earth sulfates formed are dissolved in cold water and thus separated from the insoluble mineral impurities. Rare earth elements in the aqueous solution are then separated by displacement ion exchange techniques outlined above. 

The columns are usually made from glass which is silanized to remove polar silanol Si-OH groups from its surface that can contribute to the peak tailing of the peaks of polar analytes. These columns have internal diameters of 2-5 mm. The columns are packed with particles of a solid support which are coated with the liquid stationary phase. The most commonly used support is diatomaceous earth (mainly calcium silicate). This material is usually acid washed to remove mineral impurities and then silanized as shown in Figure 11.4 to remove the polar Si-OH groups on the surface of the support, which can lead to tailing of the analyte peak. 

Mineral impurities may be detested by incinerating a portion of the sample in a platinum capsule. Pure quinin leaves no residue. Or a portion of the suspected quinin may bo treated with alcohol at a gantlc heat. Quinin dissolves, whilst any mineral matter which may be present, as well os gum, starch, stearin, will romain untouched. If a portion is burned upon platinum foil, sugar and margario acid may be detected by their peculiar smoke and small... 

By submitting various metallic sulphides, e.g. those of bismuth, silver, cadmium or zinc, to the action of a solution of sulphur chloride in benzene or toluene, a greenish-blue precipitate of sulphur is obtainable, but the product invariably contains several units per cent, of mineral impurity.2 The suggestion that Ultramarine owes its colour to the presence of a blue variety of sulphur appeal s to have little probability, especially in view of the stability of this substance towards heat,4 and indeed the true nature of the blue- or green-coloured precipitates of sulphur, obtained by any of the afore-mentioned methods, requires much more experimental investigation before the existence of a blue or green modification of sulphur can be accepted. 

Purifying coal prior to combustion usually involves pulverizing the coal and mixing it with detergents and water, as is demonstrated in Figure 19.7. The density of coal is lower than the density of any of its mineral impurities. A proper adjustment of the solutions density therefore allows the coal to float to the surface,... 

The pink or brick diatomite has been crushed, blended and pressed into bricks, which are calcined (burned) at temperatures greater than 900°C. During the process the mineral impurities form complex oxides and/or silicates. 

Deactivation of all diatomite supports is necessary for most applications since the surface contains mineral impurities which can cause decomposition of the sample or stationary phase. These impurities can be removed by thoroughly washing the support with hydrochloric acid and then washing to neutrality. Most commercial supports are available in an acid-washed grade. 

The chemical components of beeswax are alkyl esters of monocarboxylic adds (71-72%), choiesteryi esters (0.6-0.8%), coloring matter (0.3%), lactone (0.6%), free alcohols (1 — 1-1%), free wax acids (13.5-14.5%), hydrocarbons (10.5-11.5%), moisture and mineral impurities (0.9-2%). Myricyl palmitate (C46H92O2) is the principal constituent of the simple alkyl esters (49—53%) the simple esters include alkyl esters of unsaturated fatty acids. The complex esters include hydroxylated esters the chief component of which is believed to be ceryl hydroxypalmitate, CudlmOj. The principal free wax acid component is ceiotic acid (C26H52O2). The principal hydrocarbon is hentriacontane (C3iHm). 

The white dextrins are the least soluble in cold water, the insoluble part consisting of soluble starch and of more or less marked proportions of organic (cellulose, gluten, etc.) or mineral impurities (sand). 

Coal washability determination of the theoretical limits for the removal of mineral impurities from coal by beneficiation processes that rely on specific gravity separation (ASTM D-4371). 

Primary clay, known as kaolin, is found in the same place as the parent rock. Kaolin is formed by the weathering of feldspar. Kaolins are coarse in particle size and therefore nonplastic compared to most sedimentary clays. Kaolins are relatively free of mineral impurities such as iron. 

Stricktly speaking, kerogens are always inhomogeneous and always contain impurities" such as graphite particles, carbon-black carbonaceous particles at various degrees of metamorphic alteration and mineral impurities. An electron microscope is a particularily suitable tool for studying these phases present in kerogens, since particles less than 1 pm can be examined (Oberlin et al., 1980) 19). 

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