Carbonaceous matter

Generally, cmde sulfur contains small percentages of carbonaceous matter. The amount of this impurity is usually determined by combustion, which requires an exacting technique. The carbonaceous matter is oxidized to carbon dioxide and water the carbon dioxide is subsequently absorbed (18). Automated, on-stream determination of impurities in molten sulfur has been accompHshed by infrared spectrophotometry (35). 

Several common acid treatments for sample decomposition include the use of concentrated nitric acid, aqua regia, nitric—sulfuric acids, and nitric perchloric acids. Perchloric acid is an effective oxidant, but its use is ha2ardous and requkes great care. Addition of potassium chlorate with nitric acid also assists in dissolving any carbonaceous matter. 

The color of pure diatomite is white, or near white, but impurities such as carbonaceous matter, clay, iron oxide, volcanic ash, etc, may darken it. The refractive index ranges from 1.41 to 1.48, almost that of opaline siUca. Diatomite is optically isotropic. 

Solid carbon, however produced, presents a hazard. It may be burnt off at low temperatures, with free access to air, without harm to the crucible, but it should never be ignited strongly. Precipitates in filter paper should be treated in a similar manner strong ignition is only permissible after all the carbon has been removed. Ashing in the presence of carbonaceous matter should not be conducted in a platinum crucible, since metallic elements which may be present will attack the platinum under reducing conditions. 

Note. If the wet precipitate is heated directly, caking occurs which renders the complete oxidation of the carbonaceous matter very slow. If alkali metals were originally present, the ignited oxide must be washed with hot water, filtered, and re-ignited to constant weight. 

The veins are composed mostly of quartz and a small amount of sulfide minerals (pyrite, pyrrhotite, arsenopyrite, chalcopyrite, sphalerite, and galena), carbonate minerals (calcite, dolomite) and gold, and include breccias of the host rocks with carbonaceous matters. Layering by carbonaceous matters has been occasionally observed in the veins. Banding structure, wall rock alteration and an evidence of boiling of fluids that are commonly observed in epithermal veins have not been usually found. 

There are two possibilities here to explain this correlation. One is that isotopically heavy sulfide sulfur derived from seawater sulfate was fixed in shale because reducing agency of shale with carbonaceous matters is thought to be stronger than that of sandstone. The ore fluids extracted this sulfur. Gold of low NAg precipitated in shale like the Kuryu deposit under more reducing environment than in sandstone like the Saigane deposit. 

Ores which are associated with carbonaceous matter which reabsorbs dissolved gold. 

Schmitz, P. A. Duyvesteyn, S. Johnson, W. P. Enloe, L. McMullen, J. Ammoniacal thiosulfate and sodium cyanide leaching of preg-robbing Goldstrike ore carbonaceous matter. Hydrometallurgy 2001, 60, 25 40. 

Alien-King R, Grathwohl P, Ball W (2002) New modeling paradigms for the sorption of hydrophobic organic chemicals to heterogeneous carbonaceous matter in soils, sediments, and rocks. Adv Water Resour 25 985-1016... 

In the step-feed system used for nitrification and denitrification the feed is introduced along the length of the basins into anoxic ones formed at these entry points (Figure 4). This system has the advantage that a large portion of the mixed liquor is retained in the first number of sections, which allows the breakdown of adsorbed carbonaceous matter and ensures that the nitrifiers are not washed out of the system. However, since a portion of the influent organic carbon and ammonia enters near the end of the tank, some will wash... 

Carbon dioxide is found throughout nature. Its concentration in the air is 0.036% by volume. It is the primary component of exhaled air of all animals. It also is the product of oxidation of all carbonaceous matter and an end product of complete combustion. It also is found dissolved in natural waters. It occurs in the earth s crust and in volcanic eruptions. 

Carbon monoxide is found in varying concentrations in unventilated and confined spaces resulting from partial oxidation of carbonaceous matter. Burning wood, paper, kerosene, or other organic materials in inadequate air can produce this gas. It also is found in automobile exhaust and tobacco smoke emissions. 

Reaction with sodium hydroxide in the presence of carbonaceous matter and lime produces sodium chlorite. 

M.-E. Chevreul, near the beginning of his surprisingly long career, studied Hatchett s papers and prepared some of the tannin. Hatchett had found that pit coal which contained no resinous substance was dissolved completely by nitric acid and converted into the artificial tannin, whereas any resinous matter remained undissolved. When Chevreul treated pit coal with nitric acid, however, evaporated the solution, and poured it into water, a yellow matter separated, which was much more abundant than what remained in solution, and had no property that rendered it similar to resins. . . yet I do not allow myself, said Chevreul, the least reflection on the labours of that celebrated English chemist, as I am too fully aware that different modes of operating and the different varieties of the bodies examined. . . may produce a variation in the results.. . Chevreul found that the water-soluble substance which precipitated gelatine copiously was a compound of nitric acid and carbonaceous matter. . (22). These artificial tannins... 

Ash, Shall not exceed 0.01 %. For this test, a 50g sample is weighed on a triplebeam balance into a dish, previously tared on an analytical balance, and heated over a free flame until the vapors continue 00 bum after removing the frame. (During the operation the sample should be protected from drafts). When the combustion dies out, ignite the residue at low red heat (or in a muffle fumace at 800°) until the carbonaceous matter is consumed, then cool in a desiccator weigh... 

Ignite the crucible and contents in a muffle furnace until all carbonaceous matter has been burned off, cool in a desiccator and weigh. Calculate the loss In weight of the crucihle to... 

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