This paper considers three aspects of cemented fill practice and research in Mount Isa. Firstly, an account is given of the use of Portland cemented hydraulic fill, considering mainly the role and specifications of the fill used but including- brief description of fill preparation and placement._x000D_
Data resulting from a Portland cemented hydraulic fill sampling, curing and testing campaign covering about 18 months of operating practice are presented, analysed and discussed. These yield information indicating the mode of operation of a fully-automated fill preparation station, as well as a means of comparing field and laboratory strength results. A technique with potential for use as a fill quality control without actual strength testing is also described._x000D_
Results of a fill research program conducted by the author in Mount Isa since early 1968 are presented, involving both Portland cemented hydraulic fill and alternative, cheaper, additives for cementing hydraulic fill.