Abstract: In a gold refinery， the pregnant solution purification process uses a chamber filter press with non-woven filter cloth. Problems such as poor purification effect， short filter cloth service life， and low gold mud grade exist. By adding a layer of filter aid material ("pulp hanging") on the surface of the non-woven filter cloth of the chamber filter press and removing the original series secondary purification filter press， the purification effect of the pregnant solution can be effectively improved， the turbidity of the pregnant solution can be reduced， the gold mud grade can be increased， and the service life of the filter cloth can be extended by more than 60 %， with significant economic benefits.