RECONCILIATION OF MINERAL PROCESSING DATA CONTAINING CORRELATED MEASUREMENT ERRORS

Steady-state values of stream properties (species flowrates) of a mine ral processing circuit are usually estimated by averaging values sampl ed during a given time interval. A major source of data inaccuracy is the integration error, i.e. the error generated by the dynamic variati ons of the stream properties around their steady-state values. The pap er shows that these sampling errors are significantly reduced by appro priate reconciliation methods based on material conservation equations . The optimal error compensation is obtained by minimizing a quadratic function where the weighting factors take into account the integratio n error covariance from stream to stream and species to species. The m ethod is illustrated for a flotation circuit modelled by a state-space representation. The data variance reduction is compared for different weighting strategies of a quadratic reconciliation criterion. For the studied system, it seems that ignoring measurement error correlation, using a standard weighted least-squares criterion instead of the opti mal quadratic function, does not degrade too much the ability of the r econciliation procedure to reduce the data variance. (C) 1998 Elsevier Science B.V. All rights reserved.