Abstract: An automatically-regulated, self-flushing method of filtering a liquid suspension includes passing the suspension through a granular filter material. The flow of suspension is halted to relieve the pressure in the system, so facilitating the settling of the removed particles down the filter. Further settling of the particles may be achieved by passing an airstream through the filter material. A reverse flow of the filtrate then effects a backwashing action on the filter material so that further settling of the particles is encouraged. The filter material may be contained in a drain passage which follows a generally sinuous path. The drain passage may serve a waste landfill site in which toxic, hazardous or domestic waste is disposed.

Abstract: A grouting material which is self-dispersing when brought into contact with a volume of water containing liquor or slurry and is settable to a solid mass after such dispersion, the material being in the form of self-dispersing granules or pellets and comprising a blend of component (A): a cementive constituent forming from 10 per cent to 95 per cent by weight of the composition; component (B): a dispersing constituent forming from 2 per cent to 75 per cent by weight of the composition; optional component (C): a swelling constituent which forms from 0 per cent to 50 per cent by weight of the composition; and component (D): a binder constituent which forms from 0.1 per cent to 10 per cent by weight of the composition; the percentages of components A, B, C and D adding to 100 per cent.