business improvement in the mining t and metals industrythe improvement process, integrated with...

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Business strategy

As a price-taker in a commodity industry, eachmining and metals business is seeking tosustainably reduce unit costs and maximisetonnage from its capital assets. Businesssuccess is based on accessing the best resourcebase, and then utilising this resource at thelowest cost. This paper focuses on increasingproduction and reducing unit costs (Figure 1),through using the optimum technology in themost effective manner.

Mining and metals operations are capitalintensive (high capital invested per unit ofrevenue), with a comparatively slow techno-logical obsolescence. A measured approach toreplacement of fixed assets is essential. Mostsectors have relatively open access totechnology through a common platform ofequipment and technology suppliers.

Maximizing production, either throughequipment selection or improved operationalperformance, is a significant component ofbusiness improvement initiatives. Sustainablereduction in unit costs, by eliminatingactivities that do not contribute to safe andreliable production, is also critical to businesssuccess.

These contributions to shareholder valueare built on two alternative approaches:

➤ Continuous improvement (CI) throughelimination of the multiple forms ofwaste that exist in every operation.Examples are: accidents; recovery losses;excess inventory; multiple handling ofmaterials; rework and scrap; waitingtime

➤ Investing in the Enhanced Technology tomaximize: throughput; conversionefficiencies; and human productivity.

A case study

To illustrate the principles underpinning thetwo improvement methodologies, a case studywill outline relevant examples. It is based onthe improvement journey to extend theproductive life of an aluminium smelter. Theprinciples can equally be applied to otherbusiness decisions such as: fleet upgrade in anopen pit mine; increasing tonnage andrecovery in a gold plant; changing the mineralprocessing circuit; reducing the unit costs of apgm operation; or improving safety in anunderground mining operation.

In aluminium smelting, the productionparadigm is set by the cell technology in thereduction lines. As the highest capital cost, thehundreds of reduction cells form the bottleneckof the plant. Technology development over thepast century, has progressively expanded theelectrode dimensions of the cells. Hence, at thetypical current density, the production capacityof each new generation of technology has beenenhanced. The dimensions of the hundreds ofreduction cells, and their associated supportinfrastructure, are essentially fixed for the lifeof the plant.

Business improvement in the miningand metals industryby A.O. Filmer*

Synopsis

In the mining and metals industry, business strategy demands thatleaders extract more from any set of capital assets. Thisimprovement is achieved through a combination of continuousimprovement and upgrading of the assets.

Continuous Improvement involves a series of incrementalchanges in the workplace to stabilize the process, remove waste,and test the limits of process capability.

Enhanced Technology involves the replacement of an existingasset with a different process or equipment, to achieve a similarfunction in a more efficient and effective manner.

The paper compares and contrasts the two methodologies andoutlines the key business considerations which dictate how andwhen to select one or other improvement method. The paper alsoaddresses the implications for these two improvement methods forthose undertaking R&D in support of the mining and metalsbusiness.

* Filmer Consulting, [email protected].© The Southern African Institute of Mining and

Metallurgy, 2009. SA ISSN 0038–223X/3.00 +0.00. Paper received Jul. 2009; revised paperreceived Sep. 2009.

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Business improvement in the mining and metals industry

Consider an ageing 85 kA aluminium smelterapproaching the end of its long term power contract. Optionswere closure in several years at the end of the power contract,or to negotiate a new power arrangement together with: anew reduction line utilizing established 300 kA technology;retrofitting a prototype technology to enhance the reductionefficiency; or squeezing the most from the existing assets.

The initial decision was to redevelop the smelter with alarger cell using the best proven technology. However, afterdifficulties in reaching an appropriate power arrangement thedecision evolved to closure. The rate of improvementachieved over these last few years was substantial. The gainsduring this capital starved environment, together withrejuvenated power discussions, caused a reassessment of thedecision to close. The smelter is currently still in operationfifteen years later, now using a 50 year old technology base,and with most of the critical operational efficiencies matchingthe best available technology of today.

As one method to quantify the gains, 70 ktpa additionalcapacity has been created from essentially the same assets.Equivalent greenfield capacity would cost around US$350million.

The improvement process, integrated with changes in theflexibility of work practices, broke many strongly held mythsabout what is possible with old equipment.

The continuous improvement journey

CI utilizes multiple small changes to processes andequipment, to remove waste and enhance throughput from anexisting asset system. Many of the CI concepts had theirgenesis in the manufacturing industry. LeanManufacturing1,2 and Six -Sigma3 are structured method-ologies used to support the CI journey.

CI mobilizes the skills and experience of the hands onoperational team to improve and sustain their own area ofaccountability. These teams can also be bolstered with theappropriate technical skills to help select, scope andimplement the best CI projects.

CI relies on removal of variation, utilizing the rightmeasures, and eliminating waste in its many forms. The CIcycle requires three steps to reach a sustainable improvement(Figure 2).

Step 1—Standardize and stabilize

An unstable process cannot be improved. Hence, standard-ization and stabilization are initially more important thanprocess optimization.

The starting point is to establish a single best way ofperforming each routine task. This current best practice isidentified, documented and aligned amongst the workteam(s), creating an opportunity for all employees tocontribute in their own work area.

Current best practices were developed for routineproduction, maintenance and administrative tasks. Each bestpractice described the purpose, how to perform the task safelyand effectively, the scheduling, and the physical and chemicaloutput targets. This sharing of ideas across shifts, oftenhighlighted simpler and safer work procedures that haddeveloped in isolation by specific crews or individuals.

In order to embed these best work practices, a jobobservation technique was introduced. Each crew memberwould observe others undertaking the tasks and discuss withthem the safety, procedures and outcomes. These interactionswithin and between crews embedded the more consistentperformance.

As one measure, the lost time injury rates in thestandardized and stabilized operations have fallen to around10% of historical levels.

Once work routines are standardized, causes of variation(e.g. breakdowns in equipment) are more readily identified.The root causes can be systematically addressed to stabilizethe materials and work flows. Elimination of the root cause,rather than compensatory controls (no band aids), reducesthe complexity of the operation; decreases the total workrequired (do it right the first time), and enables all the majormeasures such as variation, cost, safety, throughput, etc - toimprove in unison (no tradeoffs).

Hence, the preferred hierarchy for stabilization declinesfrom eliminating the cause to better managing theimplications:

➤ Eliminate the cause (e.g. eliminate peak stresses whichdamage equipment)

➤ Manage the cause (e.g. use components which increasethe mean time between failure)

➤ Intervene before failure (e.g. inspect and replacecomponents before failure)

➤ Manage the consequence (e.g. reduce downtime bysystemizing the repair)

➤ Insure against failure (e.g. add resources to address thevariation when it occurs).

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622 OCTOBER 2009 VOLUME 109 REFEREED PAPER The Journal of The Southern African Institute of Mining and Metallurgy

Figure 1—Asset effectiveness can be improved through continuousimprovement or enhanced technology

Figure 2—The continuous improvement cycle

3) Integrateand optimize

1) Standardizeand stabilize

2) Measureand control


Where necessary, the current best practice is upgraded toaccommodate the new opportunities. Documentation, trainingand follow up with workplace observations are all essential tostandardize and sustain the each improvement.

As each special cause of variation is addressed, theproduction system as a whole is stabilized. Emergenciesbecome rarer, and work is undertaken to plan. Start/stopoperation of equipment is eliminated thereby reducing thestress on each component of the system. Each work team canrely on a consistent feed from its internal supplier and canproduce a more consistent product for its internal customer.The more predictable work pattern allows scheduled time forpreventative maintenance (hence further increasing stability),and people can be freed up for improvement teams, thusfurther reinforcing the virtuous cycle of improvement.

The overhead cranes in the reduction lines werenotoriously unreliable, but capital was tight. Since many ofthe daily tasks of tending the more than 500 reduction cellsrequire the use of these cranes, work flows were frequentlydisrupted both within the reduction area and with flow oneffects up and down stream of reduction. These disruptionsalso led to variation in cell condition as the time betweenanode setting and tapping events was often variable.

Scheduled maintenance and more systematic recording ofhistory enabled effective root cause analysis. The resultantimprovements involved replacement of worn crane rails; andair conditioning and modernizing the cranes’ electricalcircuits. These changes considerably improved the reliabilityof reduction line operations, creating a virtuous cycle ofimprovement in the upstream anode rodding anddownstream casting areas of the smelter.

Implementing CI in an isolated part of a production chainis not sustainable. Waves of variation will flow through,overwhelming the stabilisation in any particular work area.The root cause of a particular variation may be locatedoutside the particular work area, requiring improvementteams which overlap the relevant areas. This builds theunderstanding of the impact of each area of an operation onits internal suppliers and customers.

Step 2—Measure and control

If a process is not measured, it cannot be controlled.Materials and information must flow from area to area of

accountability. The production chain is a set of suppliers andcustomers, with measures which integrate each link of thesequential process. The mapping and structuring of thesemeasures across the manufacturing flow is often termedSIPOC (Supplier, Input, Process, Output, and Customerillustrated in Figure 3)

Good control demands a manageable number of agreedmeasures between work areas, focused on the importantspecifications.

Starting with the customer, important measures areidentified, each with a clear business consequence, if theprocess is outside the specification limits. The measuresprovide the basis for developing a process control plan, whichin turn dictates a set of preferred inputs from its internalsupplier. And so, the development of measures and controlplans can be progressed back up the supply chain. As processsuboptimization can occur where costs or quality have beenoptimized, independently of the impact on customers andsuppliers, the discussion of comparative costs and benefitsbetween the teams allows adaptation to maximize the overallbusiness value.

Commencing SIPOC at the customer end of the chainencourages the removal of variation at the input of anyprocess, rather than building the additional cost andcomplexity of compensatory controls. In this way, the naturalvariability of the orebody is addressed as early as possible inthe production chain.

Visibility of the measures in the workplace is important toenable team leaders and members to rapidly absorb thestatus of a process. Control limits dictate when to (and whennot to) intervene in a process. Measures also enable rootcauses of variation. (e.g. by using the statistical analysistools to link cause and effect) to be identified.

Variability in time and materials flow requires specialattention. The natural inclination is to maximize output in agiven period as time is a resource which cannot be replaced.However, overproduction in an isolated section simply buildsinventory, an expensive form of capital. These inventorieshide the root causes of unreliable equipment, and add costsdue to the associated multiple handling.

This control of (not maximizing) production rates is afruitful area for improvement for front line leaders.Manufacturing plants use the central conveyor to regulate thedrum beat of their process, but the mining and metalsindustry has set up a discontinuous batch process with themaximum production flow set by the process bottleneck.There is no ready means of enforcing the harmony in theupstream and downstream production processes. For aninterdependent sequential process it is often faster to goslower.

During tapping, the metal was occasionally contaminatedwith bath, which accumulated in the transport crucibles. Thecleaning of each crucible was condition based, and carriedout in another part of the plant. The bath accumulationresults from entrainment, particularly in the latter part of the

Business improvement in the mining and metals industryTransaction

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Figure 3—SIPOC-Process measures and utilized to optimize workflows across areas of accountability



tapping cycle where the metal bath interface is close to theheight of the tapping pipe. Visually displaying the data onbath accumulation allowed each tapping crew to slow theirrate of tapping. With lesser accumulation of bath, thecleaning crew was able to reduce the average volume of bathcontamination in each crucible. The volume gains weresufficient that an extra cell of metal could be tapped into eachcrucible. This in turn freed up sufficient time to slow thetapping process even further.

The timeliness of a measure enables an intervention tothe actual process, not what was happening when sampled afew hours ago. Online measurement has enabled much betterprocess control and inputs to automation.

However, ready access to data can also encourageinterventions where a process is operating within normalvariation, thereby potentially creating additional variation.Until the purpose of each measure is understood, the controland specification limits are established with a standardisedresponse plan, the full benefits of online measures will bedifficult to capture.

The operational measures used to control the processcascade upwards to business performance measures. Thisintegration between the process measures (what is importantfor maintaining material and work flows), and the verticalmeasures (what is important for the business on a monthlyor yearly basis) provides the context for a person’s role in thesuccess of the enterprise. Sub optimization to meet a singledimensional goal can be avoided, and people in differentareas can work as a part of a larger harmonized team.

Step 3—Integrate and optimize

Waste can be eliminated from a stable system.Some waste is eliminated automatically in a stable system

(e.g. accidents) but other forms (e.g. double handling, scrap,waiting time, insurance resources) must be consciouslyremoved to sustain the improvement. As an example, excessstockpiles or crew sizes simply hide the root causes ofequipment breakdown and encourage ongoing inefficiencies.This progressive removal of waste uncovers the next set ofopportunities to improve the materials and work flow.

The linkage of process and business measures, highlightsbusiness leverage areas for improvements. Examples ofspecific business leverage points are: the bottleneck of anintegrated production system; the efficiency of a high costprocess; the performance of a hazardous task; the on timedelivery of quality product; and the reduction of hazardousemissions. These leverage areas need to be specially targetedfor improvement, as too many parallel efforts to changeprocess capability can actually take the overall systembackwards, as each individual change will cause variationelsewhere.

As the variation is reduced, the leverage process can bemoved closer to the preferred output without breaching theupper specification limit (Figure 4). Therefores, processthroughput (or any other beneficial dimension) can beincreased.

As the capability is increased, the operational managermust establish whether the upper specification limit is real, orsimply someone’s comfort zone expressed as a limit. Simplypushing existing assets their operating capability exposes a

risk of catastrophic failure, but some ‘well known constraints’turn out to be mythical. The Six Sigma methodology3

provides guidance on the design of experiments to test thesecritical specification limits.

Every cell in a reduction line operates at the same currentand the maximum amperage reflects the condition of theworst cells. Reducing the variability enabled improved currentefficiency and cell life at fixed amperage, but the impact ofincreasing current density above the industry norm wasuncertain. A booster rectifier was introduced to the end ofone reduction line to trial increased current in a small cohortof cells, without risk of losing control of the whole line. Asthe current was increased, changes to operating proceduresand equipment design were required to stabilize the operationin the trial cell cohort. Once developed, the amperage on theremainder of the line could be converted to the newprocedures. Then the cycle of establishing stable operation onthe main lines, and trialing a higher amperage would beginagain. This approach has enabled increases in current densityto almost double metal production in 15 years. Cell life,current efficiency and power efficiency have all improved.

The capital intensity of the mining and metals industrymeans asset throughput is critical. The three components ofOverall equipment effectiveness (OEE) of the bottleneckprocess; yield, utilisation, and throughput rate, must all bemaximized (the OEE of a non bottleneck process cannot beincreased except by removal of assets). Examination of thecauses of variation in each of the factors contributing to OEE,provides focus on where and how to improve overall plantproductivity.

The increase in metal production from the smelter meantthat casting capacity was becoming a potential bottleneck inthe overall system. Instantaneous casting rate was limited bythe heat extraction from the mould, and yield was alreadyapproaching 100%. The downtime required for maintenancewas commensurate with the tasks required, and so the initialresponse was to consider an additional casting station at acost of around US$50m. However, examination of OEEillustrated a production gap after shift change when thecasting crew was waiting for metal delivery to prepare thealloy in the furnace. In reduction, the tapping crew wasgetting into their production rhythm at the start of shift. Thisvariation was easily resolved by offsetting shift patterns, sothat casting could be maintained throughout the day usingthe existing metal deliveries and furnaces.

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Figure 4—As variation is reduced the process mean can be increased


The capability of a critical process can be increased untilthe equipment or process reaches a true technical limit. Thislimit is characterized by an increase in variation that morethan offsets the advantages of increased throughput. Thetechnology of the equipment or process then needs to beaddressed to continue the improvement journey.

The CI methodology appears straight forward, and hastransformed the manufacturing industry. Most miningcompanies have engaged in at least part of the CI journey,but many have foundered in the journey due to decisions thatseem counterintuitive to the traditional approaches to miningand metals. A few examples are:

➤ Standardized work is more important than heroicperformance

➤ CI is not sustainable in isolated parts of the productionchain such as business leverage points

➤ Critical measures should be visible in the workplace notin computer systems

➤ Optimising ‘individual measures’ is often to thedetriment of the overall system

➤ Equipment throughput should be stabilized beforebeing accelerated

➤ Capital should be the last alternative to increasecapacity

➤ The variability of the orebody must be activelymanaged, early

➤ Waste comes in different forms:– ‘Just in case’ inventory– Isolated periods of record production – Adjusting processes that are ‘in control’.

The enhanced technology journey

Ultimately, enhancement of technology underpins all theindustry improvements in efficiency, and results in the longterm price declines of commodities.

The initial design of any integrated system of assets setsthe paradigm for its operating life. Decisions during initialdesign and construction are taken with limited knowledge ofthe resource, or the future technological advancements inequipment, or the future evolution of the market.Opportunities to improve on the initial design are expected.

Unlike CI, improvements through enhanced technologyare best made through a focused and well structured designand implementation team, working outside but in closeconsultation with the operating team. This team structureenables the specialist skills and systems required inequipment definition, procurement, construction andcommissioning

Where equipment has a finite life (e.g. haul trucks) orrapid technological obsolescence (e.g. personal computers),every replacement cycle provides an opportunity to evaluatenew technology. Also, when the fixed equipment is limitingthe efficiency or throughput of an overall production system,new technology needs to be explored.

The resulting investment may be:

➤ like for like replacement to increase asset reliability ➤ improved measurement and control systems to utilize

the asset more effectively ➤ updated or larger technology to enhance process

capability

➤ alternative chemistry or physics to achieve the functionin an alternative process e.g. resin in pulp for uraniumrecovery, or use of high pressure grinding rolls.

Reduction line off gas has a fluoride content which mustbe captured to protect both the working and ambientenvironment. Better hooding practices improved theworkplace environment, but the ducted off gas of the smelterwas being treated with an older wet scrubbing technology.Despite numerous efforts to improve the contact efficiency ofthe wet scrubbers, emission levels to the ambientenvironment remained well above those achievable with dryscrubbing (adsorption onto the alumina feed to the smelter).Investment in state of the art dry scrubbing technology cutthe smelter emissions to world class levels, reduced thesmelter’s aluminium fluoride consumption, and reduced thetotal power consumed in scrubbing, allowing extra power formetal production.

Whilst new technology always holds out the promise ofsuperior performance, there are some complications to bemanaged.

The new equipment must operate within the overallproduction system, and the system adapted to the newtechnology. This mutual accommodation is often a factor inreaching the full capability promised by the new technology.The capacity of the new technology may be also be limited byconstraints elsewhere in the system. Examples abound wherenew equipment is justified on additional tonnage, only to findthat the bottleneck moves to the next point in the chain withonly a small increase in overall production. Ideally, the newequipment will have adequate capacity for future productioncreep, but be operable initially to maintain a stable materialsflow. This eliminates start-stop operations, and allows futureincreases without significant changes in work practices.

Once constructed and commissioned, the operationalenhancement becomes part of the overall system of assets, tobe further stabilized and continuously improved.

The hierarchy of improvement

CI and Enhanced Technology are indeed complementaryimprovement methods (Figure 5).

In the long-term, failure to invest in enhanced technologywill mean lost competitiveness. In the short-term capital mustalways be rationed to provide an acceptable return toshareholders. When should the lower risk, but potentiallyslower, CI route be followed, and when should scarceresources be refocused to introduce enhanced technology?

To standardize, stabilize, measure and control, andremove the waste associated with excessive variability, isessential for both CI and to successfully scope, design, andcommission enhanced technology. Any mining and metalsbusiness which does not have a structured approach to CI ismissing a substantial business opportunity.

However, as the business critical processes approach theirupper specification limits, the choice of resource allocationbecomes more difficult. If the choice is to enhancetechnology, there is an integration risk into the existingsystem? If the equipment is pushed beyond its specificationlimits, there is a possibility of process disruption.

The choice requires a calculated view on the financialrewards and associated risks (Figure 6).


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Financial measures (NPV and IRR) are well established.However, the validity of the underlying assumptions and theoption value of a strong competitive position requireattention. Indeed, the financial evaluation between CI andenhanced technology faces two difficult questions.

Firstly, will the promise of new technology actually beachieved? The benefit is the enhanced capability of the wholeasset system, not the independent capability of the newequipment. Thus, to evaluate the NPV, the next capabilityconstraint in the overall asset system must be known. Forexample, if the principal financial benefit is through increasedproduction, the next bottleneck in the system will set thecapacity. Even in a stable system, these secondaryconstraints are difficult to identify and quantify.

Secondly, how far and how fast can the existing assetperformance be improved? The constraint to progress must beunderstood—e.g. project leadership and resourcing, or projectscope, or a technical limit. Benchmarking provides someguidance. Stable operational periods identify the availableheadroom. The rate of draw down of inventory during a‘good run’ is another guide to ultimate capability of aparticular section of a plant. External benchmarking providesinformation on the performance achievable by othercomparable operations. Such benchmarking also promotesthe identification of an improvement pathway.

Risks are less readily quantified, albeit that a number ofrisk management processes have been established in theindustry: stagegate processes; change control procedures; andexpert teams to develop risk ranking and management plans.

The cash flow (large up-front capital expenditure) and thelack of operating experience, mean the downside risks ofenhanced technology are usually greater. To compensate, theanticipated financial returns should be higher. This focusesenhanced technology application towards the businessleverage areas—i.e. it must achieve significant benefit to oneor more of business continuity, revenue enhancement, andcost reduction.

Given the interdependence of CI and enhancedtechnology, and the necessity to manage both competi-tiveness and risk, there is a natural hierarchy to guideimprovement efforts.

For all operational and administrative activities,implement the ongoing CI cycle:

➤ Standardize and stabilize each area of the operations➤ Implement SIPOC to link areas of accountability➤ Eliminate the waste exposed by the more stable

process.

Then identify and focus efforts on processes andequipment that offer business leverage

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Figure 5—CI and enhanced technology are mutually reliant

Figure 6—Changing capability requires assessment of risk and reward

Standardizeand stabilize

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➤ Upgrade measurement and control procedures tofurther reduce variability

➤ Move the process incrementally closer to the knownspecification limits

➤ Understand, benchmark, and challenge theconstraining specification limits.

Then, for those assets that are approaching theirtechnical limit:

➤ Evaluate enhanced technology to address thebottleneck/leverage process

➤ Design and implement the project in the context of theexisting system.

Research and development of new technology

In parallel to managing today’s operations, businesses mustcreate their next generation of competitive advantage.Research and development (R&D) to support effective CI andthe development of Enhanced Technology are fundamentallydifferent in nature.

CI is based on access to data to eliminate variation(measurement, data management, control, and automation)and to test existing specification limits (process modeling)

Development of measurement and control systems hasunderpinned much of the recent industry improvement.Online measurement enables timely and consistentoperational decisionmaking. Automation provides aconsistent response to a given input, something that humansare not naturally adept at doing. Extensive data managementsystems facilitate root cause analysis, underpinningcontinuous improvement through techniques like Six Sigma.The exponential development of computing power has alsoopened opportunities for condition based processinterventions to reduce the probability of catastrophic failure,with its consequential impact on the whole productionsystem.

The number of individual reduction cells necessarilylimits the measurement and control equipment installed oneach cell. However, the high frequency voltage noise for eachcell is readily accessible and offers an online indication of thecell condition. Cells operating outside of the expected level ofnoise were flagged to target diagnosis and intervention by aspecialist operator. This simple control system to treatexceptions, combined with more regular and consistentperformance of routine work, underpinned the virtualelimination of anode effects (starvation of alumina content atthe cathode), increased current efficiency, and provided abasis to increase current density without adverse effect onthe cell.

As the sophistication of the data analysis has increased,additional information has been inferred from the voltagesignal, further enhancing the diagnostic capability. Despitebeing 50 year old technology, the cells now run atcomparable current efficiencies and only marginally lowerpower efficiencies than modern cells. Their current density is50% higher than most of their modern counterparttechnologies, making up in part for their small physical size.

Ongoing opportunities for superior measurement, controland automation are substantial, particularly throughseparating people from damaging energy, and automatingrepetitive tasks which require limited human discretion.

Effective scoping of R&D to support CI can greatlyenhance its effectiveness

➤ Is the business leverage sufficient to justify the R&Dproject

➤ Does improved control require more consistent, timely,or precise measurement

➤ Are the cause and effect of process variationunderstood

➤ Are the specification limits of the production systemunderstood?

The use of R&D to replace existing equipment orprocesses with enhanced technology is a more open field. Theslow rate of technological obsolescence in the industryreflects the challenges.

To successfully develop any new process or equipment,the accumulated benefits must justify the investment inconcept development, design, construction and earlyoperations. The cost of the R&D may be modest but thetechnology gains are uncertain and business calculations areindicative at best. The implementation cost is increased bythe bespoke engineering design. And finally, the investmentmust carry a margin to compensate for the risks. It isinsufficient for the innovative new process or equipment tobe better than the status quo. It must offer very significantadvantages, and be available at the right time for a specificapplication, and be sufficiently developed to manage theinterface issues that arise during its initial application.

The cathode of aluminium reduction cells is a metal poolof variable height, which circulates in response to the currentand magnetic fields present in the cell. Molten aluminium istapped every 24 or 36 hours.

Titanium diboride is wetted by aluminium, and for manyyears a composite cathode containing titanium diboride andcovered with a thin layer of aluminium has been underdevelopment. A slight inclination in such a cathode allowsthe freshly produced aluminium to drain into a sump at theend of the cell, enabling a narrow anode current distance,with a 15 to 20% reduction in power consumption. At thetime of the smelter redevelopment, several full scaleprototype drained cathode cells had been demonstrated,albeit with less than acceptable cell life. Despite the financialand environmental attraction of such energy improvements,the R&D to convert this promising concept into a robust andcommercially viable design is still underway 15 years later.The complexity of the system, cathode wear, heat balance,cell management practices, makes retrofitting into existingsmelters difficult. The investment in such a novel technologyin a new smelter would be a high risk option.

R&D to create new technology can benefit from attentionto project scope.

➤ Do the anticipated gains (relative to commerciallyproven alternatives) justify the combined cost of theR&D and the consequent capital expenditure

➤ Does the R&D fully enable industrial application of theconcept

➤ How can the risks of the initial application beminimized (modeling/piloting etc)

➤ Where is there an application which urgently requiresthe enhanced technology?


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It is evident that whilst new technology underpins longterm progress in the industry, it requires adventurous ideasoffering step improvements, and considerable strategicsupport.

Conclusions

Leaders in the mining and metals business are faced with anongoing dilemma: namely, to continuously improve theexisting asset base, or to seek more rapid progress throughapplication of enhanced technology.

Standardizing and stabilizing, reduction of variation, andremoval of waste from existing equipment and processes, is aprerequisite to success with either improvement pathway. Thetools to achieve this continuous improvement are wellestablished, but frequently require a counterintuitiveapproach to those typical in the mining and metals industry.

To further enhance business leverage requires aconscious risk/reward tradeoff to either operate equipmentbeyond its existing specification limits, or replace it with aninherently superior technology.

The effectiveness of R&D can be significantly enhancedby improved project scoping, to support both forms ofbusiness improvement.

References

1. WOMACK, J.P. and JONES, D.I. Lean Thinking - Banish Waste and CreateWealth in Your Corporation. New York, Simon & Schuster, 1996.

2. LIKER, J. The Toyota Way. New York, McGraw Hill, 2003.

3. PANDE, P.S., NEUMAN, R.P., and CAVANAGH, R.R. The Six Sigma Way: HowGE, Motorola, and Other Top Companies are Honing Their Performance.New York, McGraw Hill, 2000. ◆

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