National Mineral Resources University — University of Mines, Saint-Petersburg, Russia:
N. V. Nikolaeva, Assistant Professor, Candidate of Engineering Sciences, nadegdaspb@mail.ru
V. A. Taranov, Postgraduate student
A. V. Afanasova, Postgraduate student

Planning and operation of efficient ore pretreatment cycle requires a detailed analysis of strength properties and characteristics of ore. There are many procedures available to estimate ore grindability. The choice of a procedure is conditioned by the type of a grinding circuit and by the method and approach to the circuit design. Currently, one of the world’s most popular methods for laboratory investigation of the strength properties of ore are the Bond strength test and the JK Drop Weight Test developed at JKMRC, Australia. Combinations of circuits of crushing, autogenous and semiautogenous grinding, classification and secondary milling are modeled. Energy input of crushing is estimated based on the Drop Weight Test data, while autogenous and semiautogenous grinding energy consumption is assessed based on the modeling results. Modeling is also of use in planning new circuits for testing various configurations of a circuit and to improve the equipment selection. In order to analyze and reveal mathematical relations between the drop weight parameters and Bond work indexes, a data base on laboratory testing of various type ore grindability has been collected. The data base was used for statistical analyzes, plotting and for deriving mathematical relations, which showed good convergence of characteristics of impact strength (A·b), wear capacity (t_a) and ball mill work index. The research findings allow passing between the results of different tests without additional studies, which considerably shortens the period of analysis of ore characteristics. Furthermore, the research has shown feasibility of having the detailed and extensive knowledge on strength characteristics of ore as early as the stage of planning of ore pretreatment, which enables improvement of reliability and efficiency of design solutions within the entire system of ore processing.
The study was carried out for the project part of state assignment in the field of science, No. 5.1284.2014/K as of July 11, 2014.
The authors appreciate participation of T. N. Aleksandrova, Head of Mineral Processing Department, National Mineral Resources University—University of Mines, Doctor of Engineering Sciences, in the given study.

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