Mineral Processing
Gh. A. Parsapour; S. DarvishTafvisi; E. Arghavani; M. J. Rajabi; A. Akbari; S. Banisi
Abstract
The new copper processing plant of the Sarcheshmeh copper complex consists of two parallel circuits. After a primary crushing, the ore is sent to a SAG mill, and the product is further ground in a ball mill. The overflow of the hydrocyclones is fed to a flotation circuit that contains 8 rougher tank ...
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The new copper processing plant of the Sarcheshmeh copper complex consists of two parallel circuits. After a primary crushing, the ore is sent to a SAG mill, and the product is further ground in a ball mill. The overflow of the hydrocyclones is fed to a flotation circuit that contains 8 rougher tank cells (RCS130), 3 cleaner cells (RCS50), 5 scavenger cells (RCS50), and a flotation column (as recleaner). The circuit was initially designed to process a feed containing 0.8% Cu but due to a change in the ore type, the feed grade decreased to 0.6% Cu. This resulted in a reduction in the final concentrate grade and the recovery from 28% and 85.5% to 24% and 84.4%, respectively. Based on the original design, the copper and silica recovery in the cleaner cells should be 69% and 55%, respectively, but these values increased to 85% and 75% due to a higher retention time. The rather high silica recovery was found to be the main source of the lower final concentrate grade. In order to reduce the retention time of particles in the cleaner cell from 13.7 to 6.9 min, the rougher concentrates of two parallel circuits were fed to only one cleaner-scavenger and regrind circuit. This modification increased the cleaner and final concentrate grade from 15.1% and 24.5% to 17% and 26%, respectively. The overall outcome of the circuit modification was evaluated to be a 10% reduction in the energy consumption without any loss in the overall copper recovery.
Mineral Processing
M. Maleki Moghaddam; A. R. Hasankhoei; E. Arghavani; A. Haji-Zadeh; M. Yahyaei; S. Banisi
Abstract
Liner design is becoming an increasingly more important tool for the AG/SAG mill performance optimization. The Gol-E-Gohar iron ore concentration plant uses three 9 m × 2.05 m autogenous mills (AG) in parallel in a dry operation. Due to large variations in feed characteristics and inadequate ...
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Liner design is becoming an increasingly more important tool for the AG/SAG mill performance optimization. The Gol-E-Gohar iron ore concentration plant uses three 9 m × 2.05 m autogenous mills (AG) in parallel in a dry operation. Due to large variations in feed characteristics and inadequate blending, the performance of AG mills has been lower than the target value. In order to increase the circuit throughput while maintaining the desired product size, based upon physical and numerical simulations, it was proposed to convert the AG mills to SAG mills. Simulation of the charge trajectory indicated that increasing the liner lifter face angle from 7 to 30° could provide an appropriate charge trajectory in the SAG mode. Installation of the new liners and conversion of AG mill No. 2 to SAG mill, by adding 5% (v/v) balls, resulted in an overall increase of 31% in throughput (from 419 to 548 t/h). Measurement of the wear profiles of shell liners indicated that the wear along the liner length was not uniform. In order to arrive at a uniform wear profile, a new liner design was proposed. Installing the second liner design in AG mill No. 1 and converting it to SAG mill increased the mill throughput by 18% (from 413 to 489 t/h), while the liner life showed a 7% increase. Measurement of the wear profiles of the second liner set indicate that the maximum wear occurs in the centre of the mill. A new liner design was then designed by increasing the width of the lifter top from 12.5 to 15 cm and increasing the lifter height from 16 to 26 cm to enhance the liner life.
