Iron oxide bearing wastes (IOBS) are produced at every part of processing stage of sinter, molten iron and steel production. They are hard to handle and in many cases are stockpiled only to be a source of environmental pollution. However, they can be balled into pellets. Pellets characterized by...

Iron oxide bearing wastes in form of dust and sludges are hard to handle because of their micron size particles and moisture content in case of sludge. More often they are stockpiled in large quantities that can occupy large area of real and agricultural estates and cause pollution. Balling or palettization, an agglomeration process was used to process the wastes in order to address the problem of micron size particles and to make them fit for recycling back into metallic iron production route like blast furnace. Balling or green pelletization is the process of forming nearly spherical shaped granules by tumbling moistened particulates with or without binders in balling drums or discs disc. For a pellet to be effective either for being transported or for being recycled in blast furnace to produce metallic iron without disintegrating to dust its balling characteristics should measure up to required standard. Most outstanding of those balling characteristics include Drop Number, Green or Wet Compression Strength, Dry Compression Strength, Abrasion and Tumbler Indices. In this work iron oxide bearing wastes was mixed with iron ore concentrates in various proportions. These mixes were taken through balling or wet pelletization process using Radicon Balling Disc. The balls formed balls were taken through Drop number tests adopting the Free Fall method, where balls are made to fall freely from a height of 50 mm on steel surface, Green compression and Dry compression tests using a 5 kN Universal Testing Machine (INSTRON Corp., model 1011 UK) System while Abrasion and Tumbler indices tests were conducted using Tumbler Index cylinder or drum and adopting ASTM method. It was found that Drop number as high as 7.8 times, Green compression strength and Dry compression strength up to 11.7 N/pellet and 25.99 N/pellet respectively were attained by some of the pellets. The Tumbler and Abrasion indices recorded were up to above 95% and 5% respectively. These values are higher than the minimum recommended.

Automobile is an essential means of transporting people, goods and services which has impacted significantly on economic development of any nation. Maintainability and reliability in vehicles are design considerations that has the capacity to influence user's choice of owned vehicle for both private and commercial uses. Beyond the rigorous methods of evaluation maintainability of technological systems popular experience based opinion of operators of different makes of automobiles have proved to provide acceptable qualitative approach on critical decision making safe and moistenable vehicle. To demonstrate the application of participatory approach in maintainability structured questionnaires were developed and administered to operators (drivers and auto-mechanics) of selected vehicles (1997 models of Nissan Primera, Toyota Camry and Honda Accord) commonly used for private purposes in the study area. Prevailing system faults and the time to repair were determined and analysis were carried out to ascertain the significance of the result obtained which were also used to simulate some maintainability criteria of the steering system. From the result, Nissan Primera 1997 has the least Mean Time to Repair (MTTR) and Maximum Maintenance Time (M_max) of 30.4 and 52.6 minutes respectively, followed by Toyota Camry 1997 with MTTR and M_max of 39.9 and 128.9 minutes while Honda Accord 1997 has the highest MTTR and M_max of 93.2 and 143.4 minutes respectively. This work has demonstrated the evaluation of maintainability based on popular opinion of operators the system from the consideration of maintainability of steering system.