Abstract. The extraction and use of mineral resources are critical to modern societies. New technologies and practices have ensured the development of the mining industry. Currently, the industry is striving to become more efficient and more environmentally-friendly. This paper reports on continuing research at La Trobe University on the behaviour of cemented paste obtained from fine, sulphide-rich gold tailings from the local Fosterville Mine. The effects of cementitious binders and the age of the hardened cemented paste on the mechanical properties are presented. The findings to date show that there is potential to replace the current backfill material with cemented paste backfill to increase mine productivity and ore profitability.

The influence of some physical properties of cassava tubers on the mechanical compressive cracking force of TMS 30572 and TMS 4(2)1425 cassava varieties were investigated. 1200 tubers were freshly harvested from the Teaching and Research Farm of the Obafemi Awolowo University, Ile-Ife, Nigeria. Each of the cassava cultivars was about 1.5 years old. The tubers were cleaned and sliced into different lengths ranging from 25 -150 mm in steps of 25 mm. Slices of a particular length were sorted into 8 diameter groups: 21 -30, 31 -40, 41 -50, 51 -60, 61 -70, 71 -80, 81 -90, and 91 -100 mm, for each variety. The compressive cracking force of the sliced tubers was determined using an adapted Tensometer. The mechanical compressive cracking force required to break the tubers of the two cassava varieties (TMS 30572 and TMS 4(2)1425) increases with increase in length and peel thickness of tubers while it decreases with increase in diameter of tubers. Thus, these physical properties must be given a serious attention in the design and development of cassava peeling machine.