An essential tool for the optimization of mining-metallurgical processes

By Solange Vera, Research Engineer at SMI-ICE-Chile

Mining has evolved exponentially during the last decades, with the implementation of new tools and technologies which have allowed for the adaptation of current operational requirements, as well as comply with existing environmental regulations and with the demands of all stakeholders.

Among the tools used by the industry, simulation software tools have gained great relevance in decision-making processes. These tools are used by process engineers, mine planners, metallurgists, among other due to the various applications that can predict the behaviour of a process or system through mathematical modelling. In other words, simulation software can anticipate real processes and obtain the best performance indicators, thus becoming a powerful tool for the evaluation and analysis of new and current systems.

Specifically in the mining industry, simulation software is used to evaluate the performance of mining-metallurgical processes in light of operational changes, like variation of feed tonnage, percent solids in streams or particle size, as well as changes in configuration such as design parameter modifications or the order and/or quantity of equipment. This helps the engineer or operator to consider the “what if” scenario, based on virtually reproducing processes and studying their behaviour under different scenarios, making the decision process easier.

Experts at the Sustainable Minerals Institute (SMI) work on simulation and modelling of metallurgical processes and they are involved in a great number of projects related to the continuous improvement of processes. Experts at the SMI work in projects aiming to increase energy and water efficiency and the reduction of operational variability, using one of the most used software for project development, the metallurgical simulator JKSimMet developed by JKTech. This software was designed based on 40 years of research on comminution and classification processes at the Julius Kruttschnitt Mineral Research Centre (JKMRC) from The University of Queensland, Australia.

Graphics from JKSimMet software

JKSimMet is a metallurgical simulation software that provides engineers with the capacity to design and simulate comminution circuits, one of the most critical processes of concentrator plants due to their heightened energy inefficiency. Among the distinctive features of the software is its ease of use, which allows for it to be used both by professionals who are experts in process modelling, as well as by any professional who understands the empirical aspects of comminution. Its primary application is to carry out process analysis and existing circuit optimizations to evaluate plant performance, as well as being extremely useful to carry out conceptual designs, with the purpose of evaluating the suitability of different flow diagrams to achieve performance objectives.

SMI’s International Centre of Excellence in Chile, SMI-ICE-Chile, was part of a project to increase energy efficiency for a comminution circuit of a national concentrator plant. This circuit is comprised of a closed ball mill circuit with hydrocyclones arranged in direct configuration, which was modelled using JKSimMet to evaluate the different alternatives that allow for the reduction of specific energy consumption of the circuit. As a result of the project, small operational changes in the classification process were detected, such as changes to the opening of apex/vortex of the cyclones, which had a positive impact on the circuit’s energy efficiency. Additionally, the project concluded that, by implementing an additional classification stage with screens prior to the ball mill, the energy efficiency of the circuit is favoured by avoiding over-grinding of fine particles. These particles being sent directly to the discharge sump of the mill. The results of this work were published at the Procemin-Geomet 2020 conference.

Aside from evaluating alternatives that mitigate intrinsic inefficiencies in the comminution process, simulation also allows to tend to other recurring issues in this area: mineral variability. This translates to changes in the mineralogical characteristics of the rock which directly affect the performance of the process. In this context, SMI-ICE-Chile has carried out various projects using the JKSimMet software to evaluate the impact of rock characteristics, like variations in the parameters of fracture resistance of the mineral feed (SPI, Axb and Wi), in operational performance. This type of work allows the team to generate a group of recommendations for mine sites to adopt different planning strategies based on geometallurgical studies using geological data for making decisions at a mine and plant level, thus further promoting the integration of all areas involved in the mining cycle.

Visit to pellet plant in Huasco, August 2019, Energy Efficiency Project for CAP Minería, Chile. From left to right: José Ojeda (SMI-ICE); Luis Diaz (CAP); Gustavo Ceballos (AMTC); Norelys Aguila (AMTC); Romke Kuyvenhoven (SMI-ICE); Solange Vera (SMI-ICE); Marcin Ziemski (SMI-JMRC); Rodrigo Martinez (CAP)

This and other projects demonstrate how process simulation is an essential tool for everything pertaining to circuit analysis, optimization, design and simulation; since it eases problem solving difficulties faced by mining today, such as mineral variability and its impact on product quality, added to the efficient use of natural resources such as water or energy.

This software requires training for optimal use. In Chile and other countries in Latin America, Hexagon is the only company certified by JKTech to train and issue software licenses.

 

Contact Solange Vera for further information on this topic s.vera@smiicechile.cl

Reference

Vera, S., Kuyvenhoven, R., Sepúlveda, J., Ziemski, M. 2020. Improved energy efficiency in the grinding and classification circuit of a magnetite concentration plant, 16th International Mineral Processing Conference and 7th International Conference on Geometallurgy, Procemin-Geomet 2020, Santiago, Chile, https://www.gecaminpublications.com/procemin-geomet2020/