Flammable mine gases

Diborane(6), B2H. This spontaneously flammable gas is consumed primarily by the electronics industry as a dopant in the production of siHcon wafers for use in semiconductors. It is also used to produce amine boranes and the higher boron hydrides. Gallery Chemical Co., a division of Mine Safety AppHances Co., and Voltaix, Inc., are the main U.S. producers of this substance. Several hundred thousand pounds were manufactured worldwide in 1990. 

Heterogeneous Mixtures (Zabetakis, Flammability Characteristics of Combustible Gases and Vapors, Bulletin 627, Bureau of Mines, 1965.) Heterogeneous (poorly mixed) gas phase mixtures can lead to fires that normally would be totally unexpec ted. It is important... 

Among common areas where explosion can occur are coal mines, petrochemical plants, chemical plants, paint shops, grain handling industry, etc. Explosive limits for gases and vapors are expressed as percentages (% ), and may be defined as minimum and maximum concentrations of a flammable gas or vapor between which ignition occur. Concentrations below the lower explosive limit (LEL) are too lean to burn, while those above the upper explosive limit (UEL) are too rich. Table 7.8 lists explosive limits for some common gases. 

R. W. VanDolah et al, US Bur Mines RI No 7195 (1968) CA 70, 13126 (1969). Development of Slurry Explosives for Use in Potentially Flammable Gas Atmospheres, In this rept expts with 23AN-based slurry expls showed that it is possible to have them cap-sensitive and relatively nonincendive. All slurries that used flaked Al were sensitive to No 6 EBC (electric blasting cap) except one contg AN 47.2, NaCl 10, water 30, Al (particle size... 

Dimethy la mine and Derivatives Dimethylamine, (H3C)2NH, mw 45.08, N 31.07%. col gas at RT and liq at below 7°, sp gr 0.680 at 0°/4, fr p —92.2° extremely flammable and hazardous causes bums sol in w, ale eth. Can be prepd by passing a mixture of ammonia with vapors of methanol over a catalyst, such as silica gel. Has been used in agricultural herbicides and fungicides, synthetic textiles, fiber solvents, rubber vulcanizing accelerators and in missile fuels (Refs 1, 2, 4)... 

Fig. 3.2. Limits of flammability of various methane-inert gas-air mixtures at 25°C and atmospheric pressure, courtesy Bureau of Mines)...

Organo-silica compounds are widely used in a range of industries such as printing, oil production, and mining as lubricants and polishing compounds. They also find domestic use in silicon rubber and aerosol sprays because of their special physical properties, such as viscosity and dielectric constant. These compounds are also recognized as poisons/inhibitors in different catalytic processes, such as in atmospheric scrubbers, automobile exhausts, flammable gas... 

G. W. Jones, R. E. Kennedy, and I. Spolan, Effect of High Pressures on the Flammability of Natural Gas-Air-Nitrogen Mixtures, Bureau of Mines, U.S. Department of the Interior, Report of Investigations 4557, Pittsburgh, Pa., 1949, 16 pp. 

---