Variability in process feed poses a process control problem. Processes usin
g natural material as their feed are particulary prone to feed type variabi
lity. Usually, the process operators are responsible for dealing with these
problems. Operators would benefit from an expert system showing the curren
t feed type and its proper treatment Unfortunately: on-line detection of th
e feed type is difficult because explicit on-line measurements of the feed
type seldom exist. This paper presents a method for creating such informati
on based on the data from standard on-line measurements. Finding the correc
t combination of measurements is crucial The method described in this paper
shows how off-line information such as on-site laboratory analysis results
, can be used in this task. The paper is based on experiences acquired from
the concentrator of the Outokumpu Hitura mine. (C) 2000 Elsevier Science L
td All rights reserved.