Method for preventing the undesirable condensation of aluminum chloride in a fractional distillation column
AssigneeAluminum Company of America
InventorsRoger C. Johnson, Donald L. Stewart, Jr., Utah Tsao, David A. Wohleber
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Abstract
A method is disclosed for preventing the condensation of aluminum chloride (AlCl.sub.3) in a fractional distillation column which is operated to separate a fraction which does not include AlCl.sub.3 from a mixture containing AlCl.sub.3 and other metal chlorides and which is operated at temperatures which include the sublimation or melting points of AlCl.sub.3 at the operating pressure of the column. According to this method, titanium tetrachloride (TiCl.sub.4) is maintained in the column in an amount at least as great, by weight, as the amount of AlCl.sub.3 contained in the mixture.
Claims18
A method for preventing the solidification of AlCl.sub.3 in a fractional distillation column which is operated to separate a fraction which does not include AlCl.sub.3 from a mixture containing AlCl.sub.3 and other metal chlorides, comprising maintaining in the column an amount of TiCl.sub.4 at least as great, by weight, as the amount of AlCl.sub.3 contained in the mixture said amount of TiCl.sub.4 being sufficient to prevent said solidification.
A process for the separation and recovery of AlCl.sub.3 from a mixture containing metal chlorides including AlCl.sub.3, FeCl.sub.3, SiCl.sub.4 and TiCl.sub.4 comprising:
- (a) introducing the mixture into a first distillation column operated at temperatures and pressures sufficient to separate SiCl.sub.4 by distillation from the mixture;
- (b) introducing the undistilled chlorides from the first column into a second distillation column operated at temperatures and pressures sufficient to separate TiCl.sub.4 by distillation from the remainder of the chlorides;
- (c) adding liquid TiCl.sub.4 to the first column in an amount, at least as great, by weight, as the amount of AlCl.sub.3 contained in the mixture sufficient to prevent solidification of AlCl.sub.3 in the first column;
- (d) introducing the undistilled chlorides from the second column into a third column to distill AlCl.sub.3 from the remaining chlorides;
- and
- (e) recovering purified AlCl.sub.3 by condensing the AlCl.sub.3 vapors distilled from the third column.
A process for the separation and recovery of AlCl.sub.3 from a mixture containing metal chlorides including AlCl.sub.3, FeCl.sub.3, SiCl.sub.4 and TiCl.sub.4 comprising:
- (a) introducing the mixture into a first distillation column operated at temperatures and pressures sufficient to separate a fraction containing SiCl.sub.4 and TiCl.sub.4 by distillation from the mixture;
- (b) introducing at least a portion of the fraction separated from the first column into a second distillation column operated at temperatures and pressures sufficient to separate SiCl.sub.4 by distillation from the fraction obtained from the first column;
- (c) adding sufficient liquid TiCl.sub.4, in an amount at least as great as the amount, by weight, of the AlCl.sub.3 contained in the mixture, to the first column to prevent solidification of AlCl.sub.3 in the first column;
- (d) introducing the undistilled chlorides from the first column into a third column to distill AlCl.sub.3 from the undistilled chlorides obtained from the first column;
- and
- (e) recovering purified AlCl.sub.3 by condensing the AlCl.sub.3 vapors distilled from the third column.
Dependencies are inferred from the claim text.