Coal fluorine

Treatment of coal with chlorine or bromine results in addition and substitution reactions. At temperatures up to 600°C chlorinolysis produces carbon tetrachloride, phosgene, and thionyl chloride (73). Treatment with fluorine or chlorine trifluoride at atmospheric pressure and 300°C can produce large yields of Hquid products. 

When carbon is in the impure form of soot or coal, it combusts in contact with fluorine and then can detonate spontaneously. If the carbon is very pure, the ignition is delayed. 

Gonska H, Griepink B, Colombo A, Muntau H (1984) The Certification of the Contents of Arsenic, Cadmium, Chromium, Cobalt, Fluorine, Manganese, Mercury, Nickel, Lead and Zinc in a Coal BCR No. 40. European Commission Report EUR 9473 EN, Community Bureau of Reference, Brussels,... 

Under atmospheric conditions, a low rank coal (0.5-1 mm particle size) from Spain was burned in a fluidized bed reactor at seven different temperatures (50 °C increments), beginning at 650 °C. The combustion experiment was also conducted at different amounts of excess oxygen (5 to 40%) and different flow rates (700 to 1,100 L/h). At 20% excess oxygen and a flow rate of 860 L/h, the amount of fluorine emitted ranged from 850.7 ng/kg at 950 °C to 3,632.8 ng/kg at 750 °C. The greatest amount of PAHs emitted were observed at 750 °C (Mastral et al., 1999). 

Determination of Mercury, Fluorine, Boron, and Selenium. The Determination of Mercury. A coal sample is decomposed by igniting a combustion bomb containing a dilute nitric acid solution under 24 atm of oxygen. After combustion, the bomb washings are diluted to a known volume, and mercury is determined by atomic absorption spectrophotometry using a flameless cold vapor technique. 

Table X. Fluorine in Coal from the Lower Kittanning Coalbed, Centre County, Penn.

Specific Gravity Fraction % Coal in Fraction Fluorine Concentration (w/g)... 

Table XI. Fluorine in Coal from an Uncorrelated Coalbed, Mahoska County, Iowa...

Fluorine. Tables X, XI, and XII show the results obtained for fluorine in the coal-washing study with coals from Pennsylvania, Iowa, and West Virginia. In all three coals, the fluorine appears to be associated with the mineral matter in the coal. Therefore, removal of the higher specific gravity fractions would lower the fluoride content of the remaining coal. 

Clearly the oil is a much cleaner fuel than the original coal, from the point of view either of the environmentalist or of the plant engineer concerned with fouling of steam and superheater tubes. The sulfur contents of the oils are 0.1-0.2%, which is acceptable, but the nitrogen contents are about 0.6%, which may cause undesired NOx emissions. Some of the more toxic elements, (mercury, selenium, fluorine, and cadmium) have not yet been determined in oil. It is not clear what will be done with the solid residue whether it will be disposed of as waste or whether its small carbon content, typically 20-50% depending on the... 

Hydrofluoric acids - [ALUMINUMAND ALUMINUM ALLOYS] (Vol 2) - [ALUMINUMCOMPOUNDS - INTRODUCTION] (Vol2) - [FINECHEMICALS - STANDARDS] (Vol 10) -effect on glass [GLASS] (Vol 12) -magnesium reaction [MAGNESIUM AND MAGNESIUM ALLOYS] (Vol 15) -reaction with fluorine [FLUORINE] (Vol 11) - [COAL] (Vol 6)... 

Goldhaber, M.B., Hatch, J.R., Pashin, J.C. et al. (1997) Anomalous arsenic and fluorine concentrations in Carboniferous coal, Black Warrior Basin, Alabama evidence for fluid expulsion during Alleghanian thrusting Abstracts with Programs. The Geological Society of America, 29(6), 51. 

The narrow fluorine resonance of "Ci BF " is quite in contrast to the fluorine absorption found for the product of Illinois 6 coal with BF3. At room temperature, we observe a 0.25 mT (=2.5 G) wide, dipolar-broadened, spectrum not indicative of translation freedom. In contrast to the weakly bound complexes of BF3 with aromatic hydrocarbons, we anticipate BF3 to react strongly with oxygen functionality in the coal, through hydration with water, hydrolysis with acids (13), and ether complex formation (14), to give fluorine absorption lines which are in the rigid lattice condition. 

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