What is "direct process"

Direct \Di*rect"\, a. [L. directus, p. p. of dirigere to direct: cf. F. direct. See Dress, and cf. Dirge.]

1. Straight; not crooked, oblique, or circuitous; leading by the short or shortest way to a point or end; as, a direct line; direct means.

   What is direct to, what slides by, the question.
   --Locke.

2. Straightforward; not of crooked ways, or swerving from truth and openness; sincere; outspoken.

   Be even and direct with me.
   --Shak.

3. Immediate; express; plain; unambiguous.

   He nowhere, that I know, says it in direct words.
   --Locke.

   A direct and avowed interference with elections.
   --Hallam.

4. In the line of descent; not collateral; as, a descendant in the direct line.

5. (Astron.) In the direction of the general planetary motion, or from west to east; in the order of the signs; not retrograde; -- said of the motion of a celestial body.

6. (Political Science) Pertaining to, or effected immediately by, action of the people through their votes instead of through one or more representatives or delegates; as, direct nomination, direct legislation. Direct action.

   1. (Mach.) See Direct-acting.

   2. (Trade unions) See Syndicalism, below. [Webster 1913 Suppl.]

      Direct discourse (Gram.), the language of any one quoted without change in its form; as, he said ``I can not come;'' -- correlative to indirect discourse, in which there is change of form; as, he said that he could not come. They are often called respectively by their Latin names, oratio directa, and oratio obliqua.

      Direct evidence (Law), evidence which is positive or not inferential; -- opposed to circumstantial evidence, or indirect evidence. -- This distinction, however, is merely formal, since there is no direct evidence that is not circumstantial, or dependent on circumstances for its credibility.
      --Wharton.

      Direct examination (Law), the first examination of a witness in the orderly course, upon the merits.
      --Abbott.

      Direct fire (Mil.), fire, the direction of which is perpendicular to the line of troops or to the parapet aimed at.

      Direct process (Metal.), one which yields metal in working condition by a single process from the ore.
      --Knight.

      Direct tax, a tax assessed directly on lands, etc., and polls, distinguished from taxes on merchandise, or customs, and from excise.

The Direct Process, also called the Direct Synthesis, Rochow Process, and Müller-Rochow Process is the most common technology for preparing organosilicon compounds on an industrial scale. It was first reported independently by Eugene G. Rochow and Richard Müller in the 1940s. The reaction involves a copper-catalyzed reaction of alkyl halides with silicon metal, which takes place in a fluidized bed reactor. Although theoretically possible with any type of alkyl halide, the best results in terms of selectivity and yield occur with methyl chloride. Typical conditions are 300 °C and 2-5 bar. These conditions allow for 90-98% conversion for silicon and 30-90% for chloromethane. Approximately 1.4 Mton of dimethyldichlorosilane (MeSiCl) is produced annually using this process.

Few companies actually carry out the Rochow process, because of the complicated process technology and high capital requirements. Since the silicon is crushed prior to reaction in a fluidized bed, the companies practicing this technology are referred to as “silicon crushers”.