Valery, Valle, Roberto, Duffy, Holtham, Tabosa, Plasencia
Presented at Procemin-GEOMET 2020
ABSTRACT
At a time when the industry is faced with declining head grades, increasing operating costs, and problems associated with water and energy supply, pre-concentration offers hope. Pre-concentration can improve resource efficiency by removing gangue early in the process before energy intensive and expensive comminution and beneficiation processes. It should be implemented as close as possible to the mining face or draw points to exploit the natural heterogeneity of the deposit and maximise benefits. However, there are numerous options for pre-concentration and the performance and benefits of these are very case specific and dependant on the physical and chemical characteristics of ores.
Many pre-concentration processes will also require significant ancillary equipment for feed preparation, materials handling, and separation. Incorrect estimation of their costs can have a significant impact on the project. A proper evaluation of pre-concentration needs to consider orebody suitability, technology capability and economic viability. The in-situ grade variability of a deposit and how it is influenced by mining methods and the liberation size of gangue are key factors which are generally not well understood.
Geostatistical methods can provide an insight into orebody variability, and the overall selection of any pre-concentration solution must be an integrated approach between geology, mining and processing. Ore body knowledge, characterisation and mathematical modelling are essential to calculate mass flows and grades as required for a reliable estimate of capital and operating costs. These will facilitate economic analysis to compare options and determine the best opportunities and technologies for the specific ore and operation. Case study examples showing evaluation of pre-concentration options are presented in this paper. These include assessments of in-situ variability using geostatistics, process modelling of pre-concentration options, preliminary layouts, cost estimates, and economic evaluations.
AUTHORS
W. Valery1, R. Valle2*, K. Duffy3, P. Holtham4, E. Tabosa5, and Plasencia6
1. Mining and Minerals Processing, Hatch, Australia. Global Director Consulting and Technology
2. Mining and Minerals Processing, Hatch, Peru. Director Process Improvement
3. Mining and Minerals Processing, Hatch, Australia. Senior Process Engineer
4. Mining and Minerals Processing, Hatch, Australia. Senior Process Consultant
5. Mining and Minerals Processing, Hatch, Australia. Senior Process Engineer
6. Mining and Minerals Processing, Hatch, Peru.Junior Process Engineer
Principal author email