Date and place of thesis defense:
21.12.2005, Faculty of Mechanical Engineering
mr. sc. Ifet Šišić
prof. dr. Jovan Sredojević
Contribution to the development of methodology for evaluation and selection of machines for chopping non-metalic mineral raw materials
Machines for crumbling and grinding (chopping) of mineral raw materials, crumblers and grinders take significant place within technologies for preparation of mineral raw materials and for recycling of solid waste. A number of factors influences this selection as consequence of machine characteristics related to characteristics of raw materials, chopped products and technological conditions of the process. Manufacturers of non-metallic mineral raw materials in Bosnia and Herzegovina and wider, face numerous problems and dilemmas, and the most important are: providing quality of chopped products (civil engineering fractions and mixtures), providing continuous manufacturing process, increased working and maintenance expenses, making appropriate decision about purchasing or replacement of the machine, etc.
Taking in consideration these problems and intentions of manufacturers or investors about investments into projects for creating new manufacturing plants or introduction of new technological solutions in existing manufactures, there is a real need to find the new methodological analysis for evaluation and selection of chopping machines, which are the most important part of mineral raw material plants. Worldwide offer of grinders and crumblers is characterised by widely various types, kinds and models of these machines, which use various constructions, from conventional to modern designs, for chopping all kinds of mineral raw materials.
Available technical-technological, constructive and energetic material performances give the possibility of "freedom in choice" during evaluation of working capabilities and process position. Nevertheless, methodological research enclose obliged test period for new machine or through simulation of real conditions in exploitation which give confirmation of the selection, including periodical observation of machine performance during exploitation.
Existing or planned process requirements for manufacturing mineral raw materials, constructive-technological-energetic characteristics of grinders and crumblers, characteristics of raw materials with restraints and performance conditions, make this research more complex. Therefore, this fact gave the direction and basis for the research of new or innovated, modified or improved methodology for evaluation and selection. That had adequate research model as a result, with criterion functions established.
Key words :
mineral materials, methodology, selection, evaluation