Download - Indonesian " plant optimisation" Workshop
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7/28/2019 Indonesian " plant optimisation" Workshop
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Module 1: THE NEED FOR PLANT OPTIMISATION
Need for optimising a mining plant which has been operating successfully? Falling metal prices
Falling metal
price, in the
wake of
global
recession
Falling feed grades Rising labour cost Escalating power cost Rising metal stockpiles
Rising metal stockpile
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Maximising cash flow Political uncertainty
A copper mine, ignominiously shut
down by an African government in
2010
More stringent environmental measures
Acid mist in a
copper refinery
Module 2: CONVERTING A RESOURCE TO FINISHED PRODUCT
Prospecting for a metal Planning a mine
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Computerised planning of a mine, faster and cheaper than traditional methods
Testing to design a processing plant Running financial model Metal pricing in a financial model Thorough sensitivity analysis, this will be used as the benchmark to judge the new plant Corporate social responsibility, appeasing the locals
Corporate social responsibility, preserving the ecology of the area and livelihood of the people is
a prerequisite of responsible mining
Inaugurating the new mine. Pomp and pageantryModule 3: PLANT COMMISSIONING
Recruiting the right workers Demography of the work force, the community must be rewarded A form of aptitude testing
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Safety induction Training Commissioning
Inside a SAG mill, pre-commissioning checks
Reaching commercial production Setting up a metallurgical accounting system
Module 4: CONTINUOUS IMPROVEMENT
Fixed and variable costs Achieving higher throughput above nameplate design, profitable tonnage, Frontiers example
and the use of microphones. Profitable tonnage
Achieving higher recovery above test work design, variable cost, getting more metal out of theore. Use of reagent synergy
Continuous measures for cost reduction, product substitution, cheaper source, better quality,buying in bulk, First Quantums example on mill balls
Production bonus tied to cost savings
Attitudinal metamorphosis to accepting product substitution
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Substituted slurry pump spare from China at the cost of the OEMs
Suggestion schemes, Luanshyas example with rubber screens Measures of guaranteeing and sustaining the achievements, productivity bonus scheme Publicising the achievements using electronic boards
Module 5: PLANT OPTIMISATION TOOLS
The performance of a processing plant comprises equipment, labour and miningchemicals used
Improving equipment functionality, cost and reliability, Frontiers example Improving labours competence, knowledge transfer, Guelbs example Testing newer and better mining chemicals, reagent synergy, Balubas example Enhancing concentrate grade, this has the effect of reducing transportation cost and
improving downstream processing recovery. In the event or recovery suffering, is there a trade
off? Will it negate the gain discussed in Module 4?
Improving weightometers accuracy. Discussing the 21 possible sources of errors, many ofwhich are often overlooked, Konkolas example
Conveyor belt weightometer scale
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Running plant simulation programs to assess the theoretical capability, Grasbergs example. JKSimMet and HSC7
Module 6: ONGOING CHALLENGES, MAXIMISING THE AVAILABLE RESOURCES
Is high grade waste stockpiled separately from low grade waste
Processing waste rock low grade resource to make metal
Such waste can become a valuable resource if: Metal price improves Plant capacity outstrips mine production Technology improves A spreadsheet on a laptop computer can dictate the tonnage and grade
of waste to be treated
Module 7: PLANT OPTIMISATION IN THE GRINDING CIRCUIT
Choice of right grinding media. Every so often, a commercial decision is made to buy thecheapest grinding medium. Depending on the geographic location, grinding media can
represent 10% of a mines operating cost? Such a short sighted move could end up being
detrimental to the mine throughput
Quality forged mill balls, endeavouring to reduce operating cost
False economy, more money is spent on grinding media
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OVERY(%)
GRADE % Cu
WASTE ROCK TREATMENT
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Reduced throughput, poor quality balls occupy space in the grinding mill but do not do usefulwork
Accidents can arise from excessive handling and charging of mill balls Sulphide plant recovery is depressed with excessive iron in the pulp Gold plant recovery is depressed with excessive iron in the pulp This module examines the benefits derived in optimising a grinding circuit by using competent
grinding media
A case study of First Quantum Minerals is used to illustrate this pertinent factModule 8: CONCENTRATE GRADE vs. PLANT RECOVERY OPTIMISATION
Vary often; we look at the short term gains rather than observing the larger picture.Concentrate grade enhancement is a classical example
Immediately, because plant recovery at the mine drops, the idea is shunned, and inevitablyshelved
Grade/Recovery relationship,
striking the optimum
However, there are several benefits to be derived. If the economics are worked out, plantoperators could find that it is prudent to go for the concentrate enhancement route. This
module examines those options in details
Good froth Bad froth.... in concentrate enhancement
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%C
opperRecovery
Concentrate Grade (% Cu)
Grade vs Recovery
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Immediate benefits are: Lower transport cost to the port Enhanced downstream processing recovery A quality concentrate that is in demand Often, less flotation reagent is used to obtain a higher concentrate grade, hence the
concomitant savings
A lower volume of concentrate to filter, so savings in filtration cost A smaller volume of concentrate to handle in the filter plant so less spillage is created.
Apart from posing a housekeeping nuisance, spillage on the floor can be a safety
hazard due to slippage potential. Cash is tied up in the wrong place with spillage.
Morale declines with a dirty plant
A real life exercise of a copper plant is studied at depthModule 9: ENERGY UTILISATION AND IMPROVED USAGE
It is vogue today to minimise ones carbon footprint, energy conservation is an integral part ofthis
Energy is a major cost component; many mines generate their own power. Utilisation must bemaximised, wastage minimised and measures for continuous reduction implemented
Steady feed to SAG mills, eliminating peaks and troughs Regulating the granulometry of the feed to the SAG mill. Often there is segregation of rock on
the coarse ore stockpile. By installing a particle sizer on the feed belt, the feeders at the
bottom of the stockpile can be adjusted to meet the required size, Guelbs example
Feed segregation on a coarse ore stockpile
Supplementing plant feed with low grade resource Power factor correction
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Power factor correction, minimising energy wastage
Controlling peak demand, shutting down less important equipment to control peaks Making full use of surge capacities to achieve this, Frontiers example Making full use of plant automation to achieve this, San Christobal in Bolivia It is cheaper to crush than to mill ore
A gyratory crusher, crushing is cheaper
than milling the ore
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Copper/Gold/Silver mine in a fragile environment
Unique ecosystem that can
be destroyed by
irresponsible mining
THIS COURSE WILL
ADDRESS THESE
PERTINENT ISSUES