A Qualitative Dynamic Model of an Autogenously Mill

conference paper

English

Autogenously or semi-autogenously grinding is difficult to characterize by conven-tional modelling methods, because performance is dependent upon the quality and quantity of the rocks in the feed. These normally vary continuously and a detailed modelling exercise will only describe a limited range of conditions. This type of grinding is therefore an ideal application of qualitative modelling. Real valued variables are replaced with qualitative variables which can adopt only three values +, 0 and -. Dynamic behaviours are described in terms of changes in the qualitative values of state variables and their first and second derivatives. There are two types of milling knowledge, equation based and equation less knowledge items. Conventional quantitative models (usually sets of differential equations) can be degraded to these values are related by means of qualitative differential equations. Commonsense heuristics, experience, observations, qualitatively degraded on-line measurements are used to create equation less (sub) models. Both types of knowledge can be integrated and solved as one model. A realistic model is presented (eleven variables, three equations and 15 equations less relation is used to generate all possible milling scenarios.

Qualitative Model, Dynamic Model, Autogenously Mill

Krejčí, A. - Dohnal, M. - Dohnalová, J. - Rada, V.

25. 8. 2002

Česká společnost chemického inženýrství

Praha

80-86059-33-2

CHISA 2002

212

230

19