The development of the proposed milling circuit for the Nkomati main concentrator plant

The Nkomati ore body, situated in the Mpumalanga Province, in South Africa, is an extensive Nickel/Copper reserve being investigated by the Nkomati Jo int Venture. The extraction route for the Main Mineralised Zone of the ore body is currently being investigated. This paper describes the milling circ uit selection procedure for the Main Plant concentrator. The selection of the Nkomati Main Plant concentrator milling circuit follow ed a rigorous procedure. A key aspect in the circuit selection process was the close interaction between the relevant disciplines : Geology, Mineralog y, Mining and Metallurgical. The comprehensive circuit selection procedure based on a milling rate of 30 0 000 tons per month will be described, from the complete set of pilot and bench-scale results, the design criteria, the mineralogical factors and the Nkomati project philosophies, through to the final decisions on the circui t configuration and mill sizings. The proposed circuit for the 300 000 tpm Nkomati Main plant would be one of the largest milling installations in the world. The proposed circuit incor porates one of the largest primary FAG mills, and the largest secondary peb ble mill. A critical aspect in the circuit selection procedure was the vari ous means employed to reduce the very real risks associated with an operati on of this size. (C) 1998 Published by Elsevier Science Ltd. All rights res erved.