Indonesian " plant optimisation" Workshop

7/28/2019 Indonesian " plant optimisation" Workshop

1/10

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


2/10

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


3/10

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


4/10

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


5/10

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


6/10

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

66.0

71.0

76.0

81.0

86.0

91.0

0.14 0.24 0.34 0.44 0.54REC

OVERY(%)

GRADE % Cu

WASTE ROCK TREATMENT


7/10

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

91.5

92.0

92.5

93.0

93.5

94.0

22.0 23.0 24.0 25.0 26.0 27.0 28.0

%C

opperRecovery

Concentrate Grade (% Cu)

Grade vs Recovery


8/10

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


9/10

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


10/10

Copper/Gold/Silver mine in a fragile environment

Unique ecosystem that can

be destroyed by

irresponsible mining

THIS COURSE WILL

ADDRESS THESE

PERTINENT ISSUES

Documents

Indonesian " plant optimisation" Workshop