Trihalosilane refining method

A trihalosilane refining method, comprising:

• supplying a feed containing a trihalosilane into a divided wall distillation column;
• and
• introducing an effluent flowing out from the divided wall distillation column into a first distillation column,
• wherein the divided wall distillation column has an upper column region, a preliminary separation region, a main separation region and a lower column region formed therein, and comprises:
• an inlet port installed to introduce a feed containing a trihalosilane into the preliminary separation region;
• a first outlet port installed to enable outflow of a component in the upper column region;
• a second outlet port installed to enable outflow of a component in the main separation region;
• and
• a third outlet port installed to enable outflow of a component in the lower column region,
• wherein operating conditions of the divided wall distillation column are adjusted to satisfy the following Expressions 2 and 3,
• wherein the component flowing out through the second outlet port is introduced into the first distillation column, and
• wherein the first distillation column is maintained at an operating pressure of −0.6 Kg/sqcmG to 9.0 Kg/sqcmG and an operating temperature of 37° C. to 145° C.:
• 0.0139P3−0.6467P2+12.692P+27.716≦Tt≦0.0139P3−0.6467P2+12.692P+37.716 Expression 2
• 0.016P3−0.7386P2+14.3P+78.759≦Tb≦0.016P3−0.7386P2+14.3P+88.759 Expression 3
• wherein Tt represents a temperature of the first outlet port or the component flowing out through the first outlet port, Tb represents a temperature of the third outlet port or the component flowing out through the third outlet port, and P represents an operating pressure of the upper column region of the divided wall distillation column.