Method for purifying chlorosilanes

摘要

This method for purifying chlorosilanes comprises at least three steps among a hydrogenation step (101) and/or a chlorination step (102), an impurity conversion step (103), and a purification step (104). In the impurity conversion step (103), an aldehyde compound represented by general formula Ar-R-CHO (Ar is a substituted or unsubstituted aryl group, and R is an organic group having at least two carbon atoms) is added, and donor impurities and acceptor impurities contained in a chlorosilane distillate are converted into high boilers. The chlorosilane distillate after the donor impurities and acceptor impurities have been converted into high boilers is sent to the purification step (104). In the purification step (104), using distillation columns or the like, high purity chlorosilanes are recovered outside of the system from the top of the column to obtain high purity chlorosilanes from which donor impurities and acceptor impurities have been thoroughly removed. Thus, the content of the donor impurities and acceptor impurities in the chlorosilane distillate is reduced.