In a world of increasing energy costs and the treatment of harder, lower grade ores, the need to optimise grinding circuit performance and maximise project economics has never been greater. With years of experience in the optimisation of projects across the globe, CCS is here to assist.
It has been shown that the comminution process accounts for a large portion of operating costs and is the main consumer of energy for most mining and mineral processing operations. In addition to this the throughput of the comminution circuit is a major driver for overall project economics and cash flow generation. Optimisation projects associated with the comminution circuit are consequently essential for improving the overall profitability of mining operations. To harness this potential, a systematic approach and methodology is required. Throughput benefits in the order of 10% to 40% and energy savings of up to 10% to 20% can be achieved, often with minimal capital outlay.
The selection of an appropriate mill configuration depends on ore characteristics. As CCS has comprehensive know-‐how of concentration technologies and process as a whole, we can offer a perfect solution for your needs. Consultation, redesign of mill wear components and supply of the best milling components (linings, grates, lifters etc.) for your SAG/AG and Ball Mills.
Optimisation is a critical process for maximising the profitability of all metallurgical facilities within the constraints of the project. Comminution is generally the most power intensive process and generally consumes in excess of 50% of total site power. In the US mining industry, 40% of all energy consumption is estimated to be attributed to grinding, inclusive of mining (drilling, blasting, hauling) and processing. Grinding power alone can account for around 20% of direct operating costs in a typical gold plant, inclusive of salaries, wages, fuel, reagents, wear parts, and maintenance. These percentages can be higher for ore types requiring high power input during comminution.
The impact of comminution on project economics is also increasing with the observed quantum shift in the minerals industry to low grade disseminated ore reserves. CCS work closely with our clients to set optimisation goals; not only tonnage and grind size but improved project economics and or cash flow. The priority of these two aspects is not always the same and this difference is often not well understood by operators focussed on the process plant. Although optimisation is project specific, cash flow for the existing asset is typically targeted first, particularly in tough financial times, and project economics are targeted second, as the latter is often more capital intensive. Optimising the throughput of the grinding circuit can have economic benefits well beyond the processing plant allowing optimisation of key project features such as cut off grade in mining which significantly alters project economics.
Optimisation typically involves four principal criteria; a knowledge of the process, a methodology by which to apply this knowledge to the objective of optimisation, a baseline by which to judge the outcome of optimisation studies, and a view to constantly improve performance.
Methodology
- Desktop Audit -‐ a review is done of the client supplied data and goals are outlined.
- Mill Optimisation Program -‐ a site visit is conducted with data collection and process evaluation done in situ.
Computer modelling is performed with our proprietary in-‐house modelling software coupled with proven best practice comminution science. Live laboratory testing of client supplied ore samples amy also be conducted at this point.
- Recommendation and Redesign -‐ redesign for site proposal and/or material specific recommendations provided.
New lifter and mill liner design and supply. Performance testing.
- Continued improvement review process -‐ inline with best practice we set a review schedule for continuous improvement.
We offer our clients a range of comminution services over the full project lifecycle and design and delivery including:
- sample selection, metallurgical test work program design, management and results interpretation
- consulting:
- process modelling and simulation
- independent review of process designs
- review of existing operations and performance enhancement
- energy efficiency assessments
- trade-‐off options, optimisation and circuit/technology selection studies:
- SAG/AG
- HPGR
- Grate discharge Ball Mill options
- Ball Mill
- scoping, prefeasibility and feasibility studies
- basic and detailed design
- commissioning assistance
- mill specific energy calculation
- regrind mill evaluation.
CCS offers a complete package of comminution circuit testing, lining design, fabrication, supply and execution skills. We take test work data and design and install circuits that we guarantee will achieve specified throughput. We commission and provide operations support for our clients to enable them to achieve optimised performance.
Key Benefits
- Improvements in mill throughput
- Access to performance optimisation strategies.
- Reduction in grinding and milling operating costs Improvements in grinding and milling circuit design. Even slight modifications can sometimes lead to substantial increases in throughput and/or efficiency. In some cases, improvements can be achieved simply by changing the equipment operating philosophy or improving control strategies. More substantial changes such as grate and lifter design modification, pump upgrades, or the addition of a secondary crushing circuit may necessitate higher capital expenditures. In these cases it is generally recommended that the changes are simulated in order to quantify the potential benefits and rank options according to their merit.
- Mining processes require heavy capital investments and generates high operational costs which are mainly due to high energy consumptions. Of all the mining processes, grinding circuits are the most energy intensive component consuming up to 10 times more than crushing and 100 times more than blasting.
- On top of energy demands, there are environmental and safety costs considerations. The introduction of CO2 Cap and Trade policies in some of the developed countries is likely to be adopted by many others in the next years. Health and Safety is of increasing concern for extractive companies who have been meeting this challenge by heavy investment in training, procedures and safe equipment. Taking all these factors into consideration, the circuit configuration and selection of the equipment represents a critical cost saving by maximizes production, minimizes the footprint and achieves optimum energy efficiency.
- Increasing energy prices have highlighted the importance of energy-‐efficient solutions. The mining industry alone consumes approximately 4% of the world’s energy, half of this results from crushing and grinding operations. CCS solutions enable the processing of harder ores types with the potential for gains in energy efficiency.