The invention discloses a process and device for treating
tail gas and / or residual liquid in
polycrystalline silicon production. According to the process, firstly, the
tail gas and / or the residual liquid are fed into an
elution column, weak-
acid water with the
mass concentration being 2-5% is used for carrying out spraying and washing at a countercurrent state, washed gas enters a liquid sealing tank to be purified through
clean water, the finally released gas is discharged into air, and washed liquid serves as weak-
acid water to carry out circular spraying; after the weak-
acid water for circular spraying in the first step exceeds the limited concentration, part of waste acid water is drained, water is added to dilute the weak-acid water until the needed concentration is achieved, then, the weak-acid water continues to be used,
lime emulsion is added into the exhausted waste acid water to neutralize the exhaust waste acid water, then, a pressure filter is used for carrying out filtering, part of filtrate is reused, and other filtrate and filter residues are discharged. The process and the device ensure that the treated
tail gas reaches the standard and then is discharged; blockage of a spray head, a pipeline and equipment is avoided, and operation is safe and easy; part of the filtrate is reused, the
chemical engineering waste
acetylene sludge emulsion is recovered and used, the
water consumption is reduced, and the treating cost for tail and / or residual liquid is saved.