On-line determination of the concentrator feed type at Outokumpu Hitura mine

Variability in process feed poses a process control problem. Processes using natural material as their feed are particularly prone to feed type variability. Usually, the process operators are responsible for dealing with these problems. Operators would benefit from an expert system showing the current feed type and its proper treatment. Unfortunately, on-line detection of the feed type is difficult because explicit on-line measurements of the feed type seldom exist. This paper presents a method for creating such information based on the data from standard on-line measurements. Finding the correct 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.