A method for producing purified chlorosilanes includes bringing crude chlorosilanes, such as crude trichlorosilane and crude silicon tetrachloride, which contain a boron compound and/or a phosphorus compound, into contact with chlorine (preferably 1 ppm mole to 3000 ppm mole with respect to 1 mole of crude chlorosilanes) in presence of alkylphenol such as 2-methylphenol, and then distilling the crude chlorosilanes.

When producing chlorosilanes by a reaction between metallic silicon and hydrogen chloride, as the above metallic silicon, a metallic silicon powder having an oil adhering amount of 5 ppmw or less is subjected to the reaction as the metallic silicon.

The invention relates to a process for the preparation of trichlorosilane (HSiCl3) which comprises the reaction of tetrachlorosilane (SiCU) with hydridosilanes in the presence of a catalyst.

Realized is a solid substance concentration managing method which allows quick detection of an abnormality in a chemical reactor. The present invention is an invention of a solid substance concentration managing method of managing a concentration of a solid substance which is contained in a residue that is discharged in a reaction product gas processing step included in a trichlorosilane producing method, the solid substance concentration managing method including a concentration measuring step of measuring the concentration of the solid substance which is contained in an after-crystallization residue that is obtained by crystallizing part of aluminum chloride.

Chlorosilanes of the general formula H.sub.nSiCl.sub.4-n and/or H.sub.mCl.sub.6-mSi.sub.2, where n=1-4 and m=0-4, are produced in a fluidized bed reactor by reaction of a hydrogen chloride-containing reaction gas with a silicon contact mass granulation mixture composed of a coarse grain fraction and a fine grain fraction, wherein the average particle size of the fine grain fraction d.sub.50,fine is smaller than the average particle size of the coarse grain fraction d.sub.50,coarse.

A silicon granule, in particular, for the preparation of trichlorosilane, having a size of between 10 and 500 microns, and comprising: dopants in a weight fraction of less than 5 ppm; at least one co-catalyst selected from copper, iron, aluminum and calcium, in a weight fraction of between 1 and 2500 ppm; and metallic impurities, with exclusion of the at least one co-catalyst, in a weight fraction of less than 50 ppm.

To prevent solidified aluminum chloride from adhering to and accumulating on a pipe and also prevent stress-corrosion cracking in the pipe, a method for producing trichlorosilane includes a cooling step of cooling a discharge gas that is discharged from a fluidized-bed reactor and that contains the trichlorosilane, the cooling step involving causing a fluid to flow through a space (4) inside a side wall (3) of a pipe (10), the pipe being a pipe for discharging the discharge gas from the fluidized-bed reactor, in such a manner that the side wall (3) has a surface (1a) having a temperature of not lower than 110 C.

A production method is a method for producing trichlorosilane, the method including opening and closing, with use of a non-sliding valve (b1 to b4), an entry channel (f1), an exit channel (f2), a discharge channel (f31), and a discharge channel (f32) through each of which metallurgical grade silicon powder flows in a system for producing the trichlorosilane, the non-sliding valve including a valve body capable of being rotated without coming into contact with a valve seat.

To provide (i) a new internal member capable of accelerating reaction between a gas and a solid, (ii) a fluidized-bed reactor in which such an internal member is placed, and (iii) a method for producing trichlorosilane with use of such a fluidized-bed reactor, an internal member in accordance with an embodiment of the present invention is an internal member for use in a fluidized-bed reactor, the internal member including at least one resistive element having an upper surface having a conical or pyramid-shaped portion.

Chlorosilanes are produced in exalted yield in a fluidized bed process when the reactor hydraulic diameter, Sauter particle diameter, and superficial gas velocity are used to define a parameter space as a function of Reynolds number and Archimedes number.