In view of the permanent increase of the municipal solid waste incineration (MSWI) residues amount,
the numerous attempts to find a way of their recovery have been undertaken. In this paper the idea of the
recovery of the MSWI residues in Kłodawa salt mine is presented. The idea is to fill the waste in underground
workings, close and/or backfill the underground excavations with self-solidifying mixture prepared
on the basis of MSWI grained solid residues. Two techniques are proposed: 1) hydraulic backfill technique
(HBT) where the mixture is prepared in the surface installation and pumped down into the underground
workings through shaft and the pipelines and 2) dry waste technique (DWT), where dry grained waste is
dropped into the mine by pneumatic pipeline transport, then supplied to the underground mixture-preparing-
installation and pumped as a thin liquid or paste into the selected workings. The description of the
technology is preceded by general characteristic of the hardening backfill in underground mines and by
characteristic of MSWI residues, drafted on the basis of the literature review.