Silicon dust

The finely powdered silicide is a significant dust explosion hazard [1]. The lower explosion limit for a calcium-silicon dust cloud of mean particle size 9.7 pm was measured as 79 g/m3, in good agreement with a calculated value [2], Other dust cloud parameters are presented and related to predictions [3],... 

Finely powdered silicon can give significant dust explosion hazards. Relationships of sensitivity to spark ignition and of explosibility to particle size are studied [1]. Maximum explosion pressures of 6.4 bar, with maximum rate of rise of 884 bar/s have been determined [2], Silicon dust is likely to result from processes using silanes in the gas phase [3],... 

Little information is available on the toxicology of pure elemental silicon, which is an inert material that appears to lack the property of causing fibrosis in lung tissue. Silicon dust gave an inert response on intraperitoneal injection into guinea pigs and rats. Another study, however, reported minimal pulmonary lesions in rabbits after the intratracheal injection of silicon dust at a high level of 25 mg. ... 

The finely powdered silicide is a significant dust explosion hazard [1]. The lower explosion limit for a calcium—silicon dust cloud of mean particle size 9.7 pm was... 

It is suggested that the thermite reaction betwen silicon dust and copper oxide (the abstract does not state which) is a potential processing danger. Other thermite reactions of silicon are known and sometimes used. 

Another prominent application of FBCVD is in the manufacture of high purity silicon. Silicon seed particles are fluidized in a bed, in which a mixture of silane and hydrogen is introduced. Decomposition of silane on the silicon particles results in the formation of a pure silicon film. It is of importance to control the process in order to minimize homogeneous nucleation of silicon dust by appropriately designing gas distribution system and controlling process parameters.7,8... 

A possible source of Sb, Cd, and V is the exhaust of the vehicles driving on the road. That silicon was among these elements was somewhat surprising, but suggested that some of die ultrafine dust was from the Earth s crust. This finding suggests that road dust may be ground by continuous heavy vehicular traffic to contain ultrafine silicon dust particles on which Sb, Cd, and V condense on the particle surface. The smallest diameter fiaction of the particles was likely to have been resuspended. 

The chemistry of the process is complex. Heterogeneous decomposition results in particle size growth by direct deposition of silicon onto the particles as the silane decomposes. Homogenous decomposition occurs as the silane decomposes in the bubble or gas stream and results in silicon dust ranging from submicron size to 10 micron. These dust particles are elutriated from the reactor and represent an economic... 

Example 1 10.0 g of silicon dust, Si, is exploded with 100.0 g of oxygen, Oz, forming silicon dioxide, SIO2. How many grams of SiO are formed and how many grams of 0 remain uncombined ... 

---