Method for preparation of perfectly spherical particles of silicagel with controlled size and controlled pore dimensions

A method of preparing perfectly spherical particles of silicagel with controlled particle size and with controlled pore dimensions comprising the following steps:

• A. preparation of a hydrogel by:
• (1) acidifying a solution of an alkali metal silicate by an organic acid miscible with water;
• (2) emulsifying said solution in a combination of organic liquids which is selected from the group consisting of chloroform-hexane, tetrachloromethane-hexane, tetrachloromethane-cyclohexane, and tetrachloromethane-petroleum fraction;
• said fraction having a distillation range of 60.degree. - 80.degree. C. in the presence of octadecylamine;
• (3) agitating the emulsion until a silica hydrogel is formed;
• B. preliminary hardening of said hydrogel by heating above 100.degree. C. a suspension of the hydrogel in a liquid boiling above 100.degree. C., said liquid being selected from the group consisting of amyl acetate, dibutyl sebacate, glycol, glycerol, and phosphoric acid;
• C. hydrothermal processing of the hardened hydrogel by heating same with water in an autoclave at 150.degree. C. to 300.degree. C. at a pressure corresponding to the vapor pressure of water at the temperature used;
• and
• D. final hardening of the gel by:
• (1) heating of the gel at 300.degree. - 900.degree. C.;
• (2) boiling the gel in water;
• and
• (3) repeating steps D(1) and (2) three times.