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By T G. Vizcarra, T J. Napier-Munn, A T. Karbowiak, M G. Hart

Squeezing extra performance from existing equipment (‘sweating the assets’) is key to continuous improvement initiatives, particularly during times of cost cutting where the option of spending additional capital to facilitate circuit upgrades can be severely constrained. A common challenge, however, is identifying the best combination of settings for different process variables, as their effects can be camouflaged by interactions with other process variables and, of course, noise in historical data.This paper describes a recent investigation at Boyne Smelters Limited to identify strategies to coarsen the product of its dry, fixed-speed, open-circuit AG mill, without the need for installing pre-screens prior to the mill. The product is used as insulation material for the reduction of alumina to aluminium, and an excessively fine product was inhibiting the ability of the cover material to dissipate heat from the underlying anodes. The approach was to undertake a series of experiments, designed according to statistical criteria, to elucidate the effect of key process variables (feed blend and power draw) upon the product sizing. The results provided clarity about what strategies would encourage the production of a more desirable mill product (with some surprises). The study is a good example of how properly designed experiments can identify hidden potential in processing circuits, thereby mitigating the need for capital-intensive upgrades.CITATION:Vizcarra, T G, Hart, M G, Karbowiak, A T and Napier-Munn, T J, 2018. Getting the most from existing processes: using cleverly designed experiments to optimise the line 3 AG mill at Boyne Smelters Limited, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 207–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R. A. Winters

At the operations level, productivity is a principle key to profitability. If you are competing with other mines that are paying roughly the same wage rate and the same prices for capital, materials, and energy, the only way your profit can be greater is by producing more output per unit of input. Mines with higher productivity have higher profit margins. Higher profit margins lead to greater operating cash flow, and cash flow is what distinguishes a dog from a cash cow. The turnaround in U.S. metals during the 1980s was in large part due to incredible improvements in productivity. According to statistics compiled by Kaufmann, 1991, labor productivity, measured as tonnes of primary production/manhour, increased 64% in steel, 94% in copper, 75% in lead, 143% in zinc, 132% in molybdenum, and 75% in gold. These improvements were hard won. However, with most modernization programs now complete, measuring and monitoring productivity becomes even more important as producers strive to maintain the gains they have achieved.

Jan 1, 1993

Percussion drilling with tungsten carbide insert button bits ranks among the most significant advances in both underground and surface drilling in medium and hard rock formations. Getting top performance and life from these upfront components is not particularly difficult if one pays attention to the basics in operation and maintenance. For some reason, a few of the essential operating and maintenance steps for getting the most from these tools seem to have gotten turned around; instead of operating at the near optimum levels, some miners, in following myths or misunderstandings about them, are shortchanging their optimal utilization. Let's examine the two most harmful ones.

Jan 8, 1978

By K Sommerville, J Parkinson

"Open pit mines today have more technology and data available. The challenge is to effectively use resources to analyse and identify mine productivity improvements. AMC Consultants Pty Ltd (AMC) has completed more than 100 benchmarking studies worldwide. In the process of gathering cost and productivity data, insights have been gained on how mines are using data to drive productivity. This paper aims to share good practice on using data, what benchmarks operations should be aiming for, where mines are currently sitting, high value areas to target, and how to best prioritise improvement to meet operational goals.A key purpose of data is to assist in managing and improving operations. Key information is used to drive meetings, decisions, budget estimates and reports. Safety, equipment productivity, available stocks, grade and spatial reconciliation are examples of where data is important for management systems. The key is to keep reporting simple whilst maintaining access to source data for troubleshooting and analysis.Some operations still have paper-based reporting systems. Some operations collect data directly off machines and instruments, use cameras and have off-site control centres. The level of technology is a fit-for-purpose choice.Comparisons of productivity assumptions commonly used in feasibility studies with good practice productivity numbers sourced from AMC’s benchmarking database will be shared in this paper. A typical activity mining cost breakdown will highlight where the high value areas for productivity improvement sit.In addition to examining the productivity of each mining step it is also important to examine the impact on the mine plan. Equipment numbers, strip ratio, grade and material hardness can impact the results of bottleneck analysis. A bottleneck example case study will highlight how productivity and other factors can be used to identify and prioritise improvement opportunities.Keep it simple. Use only the critical data for meetings, decision-making, reports and plans. Knowing and communicating the key performance indicators (KPIs) you are striving for aligns the operation and prioritises improvement plans.Citation:Parkinson, J and Sommerville, K, 2016. Getting the Most Out of Technology to Drive Mine Productivity Improvements, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 84–93 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By J. W. Leonard

Introduction Gravity-based coal/mineral preparation plants must be operated to yield products of a quality satisfactory to existing markets. However, because of historic control problems, recovery is frequently sacrificed to achieve quality, resulting in losses of valuable product. Plant control has ranged from intuitive in-plant spot quality judgments made by various operators to gross methods involving such devices as density gauges, floats, grabsample on-the-spot sink/float tests, etc. Millions of tons of quality coal/minerals are lost to refuse each year, because of the historic lack of a continuous and dependable control system. The result is serious economic, as well as environmental, losses. While the economic losses are obvious, the less obvious environmental ones, in the case of coal, result from the misplacement of more ignitable quality fuel to refuse banks. Until recently, a control system capable of supplying a market-grade coal/mineral product, while continuously minimizing product losses to refuse, has been technologically unavailable. Coal/Mineral Washing Tracer System Performance Monitor (CMWTSPM) The first Coal/Mineral Washing Tracer System Performance Monitor (CMWTSPM) originated in the late 1970s as an innovative idea and ultimately resulted in Leonard Patent No. 4,345,994 issued on August 24, 1982. In a classic example of successful university basic research, the patent was followed by two US Department of Energy (DOE) merit awards for fundamental optimization research at the University of Kentucky, a number of publications, a successful applied research program (underwritten by SENTREX at Irvine, CA) and field tests at the Rochester and Pittsburgh Coal Company Keystone Mine near Indiana, PA. The system is now operational and is marketed by SENTREX as the SENTREX Performance Monitor. A diagram of the system is shown in Fig. 1. This system relies on metal detection as the basic tracing medium. Since it is capable of tracing particles as fine as 0.19-in., the system is ideal for coarse coal/ mineral cleaning processes. Basically, the CMWTSPM records the distribution of synthetic coal/mineral particles, of known size and specific gravity, between product and refuse output streams of coal/mineral washing, gravity-concentrating processes. For any given particle size, surface area and shape are constant. The particles are [ ] designed to find their way into the center of their respective inprocess specific gravity/size streamlines. The system will yield a complete partition curve to show the percentage of misplacement for any selected size/specific-gravity particle fraction, thereby providing a point-to-point insight into process failure. When used to evaluate operational processes, this full partition curve is far more diagnostic than the simplifying, derivative, single index number known as the Ep value. The Ep value is commonly used for convenience to represent symmetrical partition curves, but, if the actual partition curve is non-symmetrical, use of the Ep value can result in serious diagnostic error. While the Ep is useful in design and for rapid performance evaluation and process adjustment, the full partition curve is by far the more diagnostic. It will provide insight into the behavior of particulate flow, through non-symmetry, as a means to highlight potential systemic failures. Performance of the process is measured and improved by determining the extent of particle misplacement and by making timely adjustments to the unit to reduce the misplacement. Used in this manner, the CMWTSPM is not only a long needed processing control monitor, but it is also a very powerful diagnostic tool which, in the hands of skilled operators, has

Jan 1, 1993

By J. W. Leonard

Gravity based coal/mineral preparation plants must be operated to yield products of a quality satisfactory to existing markets; but, because of historic control problems, recovery is frequently sacrificed to achieve quality resulting in losses of valuable product. Plant control has ranged from intuitive in-plant spot quality judgments made by various operators to gross methods involving such devices as density gauges, floats, grab-sample on-the-spot sink-float tests, etc. Millions of tons of quality coal/minerals are lost to refuse each year, because of the historic lack of a continuous and dependable control system. The result is both serious economic as well as environmental losses. While the economic losses are obvious, less obvious environmental losses, in the case of coal, result from the misplacement of more ignitable quality fuel to refuse banks. A control system capable of supplying a market-grade coal/mineral product, while continuously minimizing product losses to refuse, has until recently escaped technology.

Jan 1, 1991

By W. W. Edgerton

Construction projects may be delivered under one contract package or multiple packages divided by discipline, geographic location, or other characteristics. Dividing the construction into contract bid packages is called contract packaging, and is a vital and strategic aspect of effectively delivering tunneling projects. The process of contract packaging considers many factors, including the type of project, location, and owner?s priorities. This paper describes the key facets of the contract packaging process used recently on several tunnel projects, reports, where possible, on the success of the process, and concludes with recommendations for applying this process to achieve the right contract package.

Jan 1, 2008

By Mel Torrie

1 Want access to low level vehicle data so 3rd party apps can be applied as desired 2 Hardware Agnostic (COTS plug and play) 3 Common/Open protocols that facilitate integration and the coexistence of a variety of applications on a variety of equipment 4 Minimum computer hardware footprint 5 Technology Independence (including comm. backbone)

May 1, 2013

By J Player, P Evans, G Sweby

Achieving quick underground access after the completion of an open pit mine can be critical to maintaining project value and ensuring regular ore feed to the mill. This paper outlines the design and construction for two portals in an active open pit to commence underground development quickly whilst installing appropriate ground control to maintain long term access in an uncertain setting. Implementation of the portal designs was complicated by the change in underground design from hangingwall access to footwall access late in the life of the open pit due to preferable ground conditions. The portal locations did not have easy access for ground support installation integrated into the pit design due to the timing of the underground design changes. Practical implementation of the ground support systems subsequently became a key part of the project. Intact rock strength, rock mass characteristics, gradational weathering / alteration profile and structural information were modelled against pit displacement monitoring as the basis from which the portals were located and ground support schemes designed. Conditions around one of the portals necessitated numerical modelling to estimate the appropriate level of ground control for long term stability. The design was completed whilst the open pit was actively on-going and the portal areas not entirely exposed. The rock mass assessment and analysis for the two portals indicated different ground support scheme capacities would be required. The expected level of control for one of the portals also necessitated the use of monitoring with extensometers and load cells to ensure the rock mass response and ground support scheme performed as planned. Construction of the portals demonstrates the benefit of a considered design process, a plan which allows practical installation of ground support schemes where access is limited, the benefit of ongoing monitoring to ensure performance remains within design limits and the challenges involved working within an active pit with limited floor space.

Mar 15, 2021

New knowledge has no economic value unless it can be applied, or æcapturedÆ, as the R&D jargon has it. Australia probably spends more than $500 m per year on mineral industry R&D, distributed amongst the mining companies (IR&D Board, 1997), CSIRO, the universities and others. The investors in this research (industry, and the community via government) will expect some sort of return from their investment. The return will be poor unless the know-how developed in R&D programs can be exploited. This paper explores some of the issues involved in capturing the outcomes of mineral industry R&D in a form which can be exploited for economic benefit, and suggests ways in which it might be done better. It is based on the experience of the JKMRC in conducting applied research in mining and mineral processing and delivering it to the industry. It may seem presumptuous for a research contractor to be telling its clients how to do their job. However, the process of developing, acquiring and implementing R&D outcomes has to be a partnership between provider and receiver, in order for this process to work efficiently. This applies whether the two parties operate within a single corporation (a corporate laboratory and a business unit, for example) or are two entirely independent organisations (eg a mining company and a university). Both partners have a role to play, and the best examples of realising the benefits of R&D almost always involve the open-hearted and skilful handling of this synergy.

Jan 1, 1998

By J D. Tolley

The shift towards clean energy technologies is having a significant impact on the mining industry, with the demand for minerals such as copper, nickel, cobalt, lithium, manganese, and graphite increasing exponentially. To meet the goals of the Paris Agreement, mineral requirements for clean energy technologies would need to quadruple by 2040, and to achieve net-zero globally by 2050, mineral inputs in 2040 would need to be six times more than today. The most significant driver of mineral demand is electric vehicles (EVs) and battery storage, with lithium seeing the fastest growth, and copper demand doubling over the same period due to the expansion of electricity networks globally. The demand for these minerals is expected to rise significantly as investments in clean energy technologies continue to grow in the future. As the world moves towards a decarbonised economy, the minerals industry is under increasing pressure to reduce its environmental and social impacts and meet the increased demand for minerals. Mining companies are facing additional challenges due to the depletion of near-surface mineral deposits globally, with more mines transitioning from open pits to underground. The transition to underground mining requires the right strategy to economically access deeper mineable inventories and to keep up with future clean energy technology demands to achieve net-zero globally by 2050. One key way to achieve this is through decarbonisation using ‘green’ mining technologies such as replacing current primary diesel mining fleets with battery electric vehicles (BEVs). However, these measures through electrification overlook the bigger opportunity to maximise the socio-economic returns from the mine while also reducing the overall carbon footprint. Corporate cut-off grade policy is one of the most significant influencers on the total environmental and social impacts of the mining industry. The purpose of a corporate cut-off grade policy is to implement strategies aligned with achieving all the mining companies’ corporate goals, with decarbonisation targets becoming a primary driver for mining companies. Table 1 shows the evolution of cut-off theory with the increasing number of dimensions and driving inputs per iteration.

Aug 2, 2023

By E. H. Rose

From the more distant members and some not so distant, the plaint is often heard that they cannot justify the expense and time required to attend the AIME Annual Meeting. Almost invariably, the reason given takes this form: "I just don't see that I would get enough out of it." Often the would-be clincher is added: "Besides, the meat of it all comes out in print anyway." Not long ago, a group of us who have seldom missed a meeting in recent years fell to discussing this phenomenon, and found ourselves in emphatic agreement that anyone holding such a belief indicates by his first remark that he does not know how to attend a convention, and by his second, proves it. He is, by and large, the man who has never been there, and of him, there are many.

Jan 1, 1949

By Kendall Y. Keuhey

The Mercur Mine, developed and operated by Getty Mining Company, is designed to process 3,000 tons/day of gold ore from the historical Mercur Hill mining district. The mill process involves crushing, grinding, and cyanide carbon in leach for recovery of gold ores ranging from 0.08 to 0.10 oz/ton. During the mining of normal grade ore, a substantial tonnage of material containing 0.02 to 0.05 oz/ton is mined and would be available for heap leaching. Also, Getty Mining is developing methods to test and prepare lower grade material for heap leaching by rejecting a course rock fraction from the grinding circuit SAG mill. This lower grade fraction is suitable for heap leaching, and its removal will upgrade the regular mill feed. Other test methods are directed toward leaching techniques on some 4.0 million tons of tailings that resulted from roasting and/or cyanide leaching Mercur ores in the early 1900s. The natural carbons associated with the Mercur deposits require special treatment to reduce their gold adsorption effects when leached with cyanide.

Jan 1, 1983

By Henry Antwi

The decade of the 1990s promises to be one of increasing internationalization for domestic minerals producers as they scramble to enhance relative positions in highly competitive, international minerals markets. This "international mining rush" is fueled by developing countries seeking international investment capital to explore for, develop and exploit sizable mineral endowments in an attempt to support the increasingly popular, but expensive, wave of democracy and selfdetermination sweeping the world. This "fuel" typically takes the form of revised mining codes and, often, lucrative investment incentives. These incentives include favorable tax rates, royalty provisions, relaxation of import/ export constraints, depreciation schedules, profit repatriation and other variables that can positively impact mineral investment decision making. Concomitantly, in their attempts to address real and perceived short- and long-term woes associated with enhancing competitive positions internationally, many domestic explorers and producers are attracted to the prospect of finding high-grade deposits in relatively virgin areas. Combined with the investment incentives provided by foreign governments, these high-grade deposits promise lucrative potential returns from projects having short payback periods. Classic examples of this mutual desire to intensify international mining efforts by domestic producers are illustrated by activity levels in countries like Chile, Bolivia and Venezuela in Latin America and, more recently, in Eastern Europe and select locations in the former Soviet Union. As US corporations scurry to send fact-finding, technical, evaluation and financial teams to these presently popular locations, one area of the world has received little attention - Subsaharan Africa. Specifically, the country of Ghana (formerly the Gold Coast) deserves more attention than it appears to be receiving from North American mining companies.

Jan 1, 1992

By K. Grubaugh

Ghana’s physiographic and geologic features are the basis for its long mining history. The Gold Coast colony has been a significant producer of gold. The gold of the Akan forest (Ghana) was a terminus for caravans that plied Saharan trade routes. Now it also produces significant quantities of manganese, bauxite, and diamonds In addition, the country produces kaolinite, silica for glass, salt, and both aggregate and dimensioned stone. Most secondary minerals are consumed locally but some amounts do find international markets. Ghana revised the mining laws and regulations in 1986. These revised laws dramatically increased gold production and improved the country’s economy. The success of these laws spawned imitators in other African states such as Cote d’Ivoire, Mali, and Burkina Faso. Representatives of these countries claim Ghana was their model. Environmental regulations exist but an intensive adversarial atmosphere is lacking. Ghana has also offered the mining industry incentives like accelerated depreciation rates and exemption from import duties on related supplies and capital equipment. The country has also pursued an aggressive policy to restore the nation’s business infrastructure.

Jan 1, 2001

By A. H. Burns

"Regenerative and recuperative burner systems require advanced combustion techniques to minimize NOx emissions. Various methods of pollutant minimization and furnace design considerations are described. Cited examples are a large high temperature furnace and a small Zinc vaporizing furnace. The concept of total carbon footprint is introduced. The application of Biomass combustion as an effective method of cost and green-house gas (GHG) reduction is discussed. Practical considerations of scale, location and process limitations are discussed. Two examples of biomass fired equipment are cited. Ideal sites have large biomass resources available locally. Processed biomass fuels will be an important substitute for fossil fuel. INTRODUCTIONIn 1992, I presented a paper entitled Combustion Strategies In The Modern Industrial Environment (1992). At that time an abundant supply of cheap fossil fuel made many of the measures I talked about difficult to justify for anything but new equipment.Since 1992 we, as a society, have demonstrated an ability to accelerate the pace of industrial and societal change. The term industrial revolution applied to this age of incessant change is completely meaningless, implying a discrete moment in historical time. What our society has built is a system capable of unfettered, continuous and accelerating technological change. With this change comes an increasing demand for energy and materials.This year is the anniversary of the Titanic disaster, a moment in time when technological certainty met the caprice of nature and gave us a brutal reminder of what can happen to us if we underestimate that power (Mowbray, 1912). In the intervening interval we have regained the technological arrogance that was lost in 1912 bringing us back to the problems of climate change and the need for sustainable industrial activities.We use advanced mathematics to describe many complex systems, sometimes with disastrous results. For example there has been a recent attempt to model the global economy as a completely deterministic system. This premise is flawed at its foundation as human nature and emotion are indeterminate constants in the equations, yielding probabilistic solutions at best. As engineers we are all familiar with stiff problems. The solution to such a problem is meaningless and we have all had the misfortune to live through and rue the effects of that miscalculation over the last few years."

Jan 1, 2012

By Y. Béliveau

Emission of perfluorocarbon gases, CF4 and C2F6, produced during anode effects from aluminum electrolytic cells are a significant part of the total equivalent CO2 emitted by aluminum plants. With the current concerns about global warming, the reduction of these PFC gases is a key issue in reducing greenhouse gases for a smelter and achieving GHG emission agreement goals. This paper will present the approach taken by the Alcoa vertical-stud Soderberg plant in Baie-Comeau to reduce GHG emissions generated during anode effects and close emission gaps with other Alcoa Soderberg plants. The approach has been to adapt the existing technology in place at the Baie-Comeau Soderberg plant. PFC emissions were lowered by reducing both the anode effect duration and frequency through different methods. Examples of change include: implementing skimming practices and wider side crust break area for better alumina dissolution in bath, increasing the ratio between reacted and pure alumina, reducing the time to declare anode effects in the potrooms, implementing best work practices and finally educating the workforce on the importance of reducing PFC emissions.

Jan 1, 2007

"Here, we statistically proved that giant earthquakes occur at lunar phases specific to each subduction zone. Enough attention during the lunar period, especially when seismicity is occurring, will significantly reduce damage from giant earthquakes. Two case studies in which giant earthquakes occurred after seismicity in dangerous lunar phases were discussed, and the mechanisms underlying why giant earthquakes occur around neap tide at some subduction zones were explained by prohibition of giant earthquake occurrences due to high strain rates at spring tides at N–S subduction zones. The prohibition was statistically proven for uniaxial creep tests on Inada granite with slight stress disturbances. INTRODUCTIONIn previous studies, we showed that from 1900 to present, giant earthquakes (MW ??8) have occurred at lunar phases specific to each subduction zone (Fujii & Ozaki, 2012; Ozaki & Fujii, 2012). Although we later proposed a possible reason for these occurrences, the study lacked statistical analyses (Fujii et al., 2013). Therefore, this paper shows the results of such statistical testing and presents case studies for the Tohoku 2011 and Chile 2014 events, thereby providing updated data on giant earthquakes through July 2014."

Jan 1, 2015

By D. M. Xue, T. B. Li

"With the increase of human engineering activities, global climate change and active plate tectonics movement, the giant landslide frequently occurred in southwest China, which caused huge property and human losses. Besides, the potential landslides pose severely threaten to the construction and operation of airports, railways, highways and power stations etc. In order to provide accurate guidance for the landslide investigation, stability analysis and mitigation, the giant landslide is redefined according to landslide volume, depth of slip surface, complexity of landslide mechanisms, and degree of landslide mitigation difficulty, and classified with the typological classification approach based on the twofold attributes of landslide behavior including formation mechanisms and reactivation features. Finally, the threefold particularity of the giant landslide is also summarized, which enables a more effective landslide mitigation design.INTRODUCTIONWith the increase of anthropogenic activities, global climate change and active plate tectonics movement such as continual uplifting of Qinghai-Tibet plateau and strong earthquakes, the occurrence of giant landslides was in ascending trend in southwest China (Huang, 2009), which caused serious destruction, and greatly endangers such engineering construction from safety, time and economic aspects as airports, railways, highways, power stations, etc. Giant landslides have huge scale, complex formation/reactivation mechanisms and mechanical behavior. They may not be identified during the hazard investigation, but may be firstly initiated or reactivated due to the following engineering activities, heavy rainfall or strong earthquakes. Consequently, the landslide mitigation is inevitable and costly. However, it is difficult to control the deformation of giant landslide with lack of a correct understanding of genetic mechanisms (Marui, 2012; Zhang, 2000) and the excessive large sliding forces of the slide blocks calculated by the conventional limit equilibrium method. For instance, the failure of anchored pile wall for the No.102 giant ancient landslide (Zhu et al., 2012) and stabilization measures for the Sidi Rached viaduct landslide(Guemache et al., 2011); four rows of piles had not prevented the occurrence of the No.12 landslide in a high fill slope in the Panzhihua airport (Li et al., 2012)."

Jan 1, 2015

By A. E. Clark

Rare earth compounds are widely known as possessing many extraordinary magnetic properties. In this paper, we focus on the huge magnetically induced displacements (magnetostrictions) which characterize the compounds of terbium with iron (Terfenol). Materials prepared commercially by both free-standing-zone (FSZ) and modified Bridgman (MB) techniques have now become available in large sizes and shapes. Prior to the development of the Terfenol alloys, it was possible to achieve giant magnetostrictions only at cryogenic temperatures. In the cubic Laves phase TbFe2 compound, saturation strains exceed 3000 x 10-6 at room temperature and above. Large magnetization 'jumps' can occur, causing huge spontaneous magnetostrictions with small triggering magnetic fields.

Jan 1, 1992