Chemical and Metallurgical Institute named after Zh. Abishev (Republic of Kazakhstan):

Malyshev V. P., Head of Laboratory, Doctor of Engineering

Turdukozhayeva А. М., Chief Researcher, Doctor of Engineering

E-mail (common): eia_hmi@mail.ru

Karaganda State University named after E. A. Buketov (Republic of Kazakhstan):

Kaykenov D. А., Researcher

A probabilistic model of grinding, developed by the authors, is based on similarity with the theory of molecular mutual collisions with regard to irreversible consecutive reactions with unlimited number of stages in respect of ball mills, operating in locked cycle with classifier, permit ting to propose an iterative calculation model for sands circulation computation. It is shown, that return of sands does not immediately bring mill in stationary regime, as size fraction composition changes gradually from the start of grinding process to onset of such regime, when disturbance, caused by sands fraction in starting composition of ore charge, stops changing general size fraction composition of product, dis charged from mill. In mathematical respect, this situation is described by iterative procedures, reduced to stagewise taking account of disturbance effect on resulting function, which has an effect on itself over correction on starting conditions. In the case in question the result ing function is size fraction composition of mill discharge product, and starting conditions are gradually changing size fraction composition of ore and sands mix at mill input, until onset of stationary regime. It has been established, that stationary regime is achieved in 15–20 cycles, depending on time of material retention in mill, feed ore size fraction composition, conditions of product separation into overflow and sands, and regime of mill's operation, taking about one hour. The proposed calculating scheme has no limitations in number of grinding stages, taking and not taking account of operation with classifier, and permits search variation of classification conditions, which may be used at devel opment stage of new materials grinding technology or in improvement of existing operations.

1. Malyshev V. P. Obogashchenie Rud, 1995, No. 4–5, pp. 4–14.

2. Malyshev V. P., Turdukozhayeva A. M., Kaykenov D. A. Obogashchenie Rud, 2012, No. 4, pp. 29–35.