
When to invest in process mineralogy
September 13, 2013
Mining: A Knowledge Cluster in Cornwall – 100 years of the Cornish Institute of Engineers
October 14, 2013Over the last few months, MinAssist has progressively launched a series of “Operational Health Checks” that have been developed as suite of off-the-shelf process mineralogy studies targeted at giving rapid performance gains for a minimum of fuss. Each of these fit in to a Suite of programs that are focused on bringing cost savings, recovery improvements and general risk reduction through improved understanding of ore types.
Key points within the processing circuit have been identified, and a mineralogical testwork program developed to:
– target the typical challenges encountered
– indicate overall circuit efficiency
– identify possible areas for improvement
The sample points have been pre-determined, the analytical testwork process developed, and the critical information to examine identified. This removes much of the hassle for a busy plant metallurgist looking to undertake a process mineralogical study. It also reduces the overall time-to-result: providing a concise, metallurgically focussed report of the mineralogy in a meaningful time frame.
The Health Check suite is ideal to for:
– the busy process metallurgist looking to get the best from a circuit
– taking a quick look at the health of a circuit to make sure things are running as they should be
– as a prelude to a more in-depth study based on the findings of the health check
A Health Check can be run as a one-off study, or on a routine basis to build up a complete picture over time.
There are currently three Health Checks in the Suite to chose from:
1) Grinding Health Check Fact Sheet or Related Artilce
2) Flotation Health Check Fact Sheet or Related Article
3) Tailings Health Check Fact Sheet or Related Article
More information on each of these is offered below, or you can simply follow the links to the related fact sheet or article. A complete summary of the MinAssist Health Check Suite and other services can be found on the MinAssist Website
Grinding Health Check
The grinding circuit in any operation is a major contributor to overall operating costs and should be a major focus of ongoing process optimisation and improvement programs. The grinding circuit can account for up to 40% of energy costs within a process circuit. Understanding the behaviour of material through the grinding circuit is a significant step on the right path for reducing costs, minimising energy use for sustainable practice and ultimately improving recoveries in down stream circuits.
– Mill Discharge Study – Identification of the key ore and gangue minerals, and analysis of liberation and locking of target ore minerals, or;
– Mill Feed Study – Identification of the key ore and gangue minerals, indication of target grain size and key ore mineral association characteristics, or;
– Complete Mill Study – Including both the above studies, as well as identification of possible over- or under- grinding and subsequent insights into overall circuit efficiency
Flotation Health Check
The texture of particles within a flotation cell play a pivotal role in both mineral recovery, and the grade, in the flotation concentrate. Theoretical curves can be generated based on particle mineralogy and texture to indicate the maximum grade-recovery possible for a given feed ore. Comparing this ‘theoretical’ curve to actual grade recovery will provide insight in to the efficiency of the flotation circuit. Inevitably the ‘actual’ curve will plot below the ‘theoretical’; the question is how far below and can that gap be reduced?
– Flotation Feed Study – Examine the theoretical grade-recovery for each size fraction, and compare with the ‘actual’ grade-recovery;
– Flotation Concentrate Study – Investigate the type and cause of dilution in the conc;
– Flotation Circuit Study – Combining the above two studies to give an overall snapshot of the circuit
Tailings Health Check
Lost material going out to the tailings is a hard reality – however are all the losses unavoidable without a major change to the flowsheet or the economics of an operation… or is there material that could still be recovered? A process mineralogical study of the tailings stream can provide a valuable insight in to the proportion of recoverable vs non-recoverable losses; and may pinpoint some material that can be recovered without major operational changes.
– Tailings Study – Various options based on grade, examining the characteristics of the losses including iberation and locking characteristics by size fraction, and an indication of recoverable vs non-recoverable material