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By A Chadwick, J de Ross, C Adams

Imagine a æshinyÆ new mine, $1 B in the bank and record commodity prices. So how does a company and its management team create enough tension to maximise profit and to establish a culture that can weather the good and bad times?That was exactly the situation the team at OZ MineralsÆ world class Prominent Hill mine in South Australia faced in 2009.Three years later, the harder times have come - lower though still healthy commodity prices, rising industry costs, fierce competition for talent, geological and technical issues (common to developing mines). However, the company was able to maximise profit during the good times and equip the culture to deal with the tougher times with minimal turnover.Through the combination of simple systems and processes, people development, application of commercial technical acumen and a combination of yin and yang leadership, OZ Minerals has achieved something quite rare - sustainable continuous improvement.The journey started with a vision. The EGM Operations created the æsparkÆ. The dream was to create a æfranchise mineÆ that could be rolled out to new mines and acquisitions as the company grew. However, the real leadership came from his lieutenants who provided the important yin and yang. The GM commercial provided the tools, processes, systems and the bottom line focus. The GM operations focused on culture, leadership, training and sustainability. This powerful combination (along with some good old persistence) was able to create the critical mass required to make continuous improvement go æviralÆ.This paper explores this unique case to uncover the essential ingredients that were created and mixed together. It will touch on the key human, technical and system elements that helped achieve significant improvements in plant recoveries, mine throughput and operational efficiencies, while overcoming human capacity, geotechnical and contractual challenges.CITATION:de Ross, J, Chadwick, A and Adams, C, 2012. How to create a perfect storm, in Proceedings International Mine Management 2012, pp 239-250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By D Kilkenny

This paper discusses the use of a mechanised shaft sinking machine Herrenknecht Vertical Shaft Sinking Machine (VSM) – to conduct the 93 m presink for the Wira Hoisting Shaft at the Prominent Hill Mine in South Australia. This technology has been widely used in the global construction industry, however, this was the first time it had been used in Australia and the second time in a mining application. The non-entry shaft sinking system eliminates risks associated with a traditional manual method and allows all shaft construction operation to take place from surface. The geology in the upper 100 m at the Prominent Hill mine is conducive to mechanical excavation, with expected rock strengths below 130 MPa. This enabled an alternative shaft construction methodology to be considered. The Herrenknecht VSM system was selected due to its extensive work history and demonstrated performance in similar ground conditions. In collaboration with the operations and design team, the shaft collar and surface configuration were modified to suit the requirements of the VSM, additional equipment, and loading jacks that support the pre-cast lining. Dedicated concrete moulds were designed in Germany and built in Italy. The concrete segments were cast in Adelaide and road freighted to site. This paper outlines each stage of the presink – refurbishment, transportation, logistics, establishment, operation and demobilisation. Selecting this shaft presink excavation methodology, delivered through positive collaboration and communication despite some challenges, shows the benefit to the mining industry of applying new technology and innovation to improve safety and productivity.

Mar 29, 2023

Over the last 15 years working in the mining, construction and extractive industries, one of the areas that has always concerned and at the same time drawn the author to it is the application of drilling and blasting in the underground development mining and civil construction tunnelling fields. In that time, the author has come across many drives and tunnels that are larger than design or badly damaged in the perimeter or both. When the question is asked as to why this is the case, the reply is generally æthatÆs the way it is and always has beenÆ. Sometimes it is blamed on bad ground, bad drilling, bad explosives, bad initiation or just plain bad. Most operators build a dilution factor into development and tunneling costs as an acceptance of overbreak and similarly pattern bolt everything to overcome excessive perimeter damage. This paper will attempt to unravel some of the mysteries behind perimeter drilling and blasting in underground drives and tunnels and discuss methods to reduce overbreak and therefore reduce costly dilution and to minimise perimeter damage which in turn will allow more cost-effective ground support. It should not be assumed that better drilling and blasting alone would automatically allow an operation to reduce ground support. The operator must still æreadÆ the ground and its characteristics in order to ensure sufficient ground support is placed to allow the operation to progress safely. This paper will not go into the intricacies of bolting, meshing, shotcreting, concreting and other ground support, but it will use indicative costs for the primary areas of drilling, explosives, excavation and labor to show the magnitude of cost-efficiencies which can be obtained through improved drilling and blasting applications. Drill and blast remains the most flexible and cost-effective method of underground excavation as long as it is applied safely and effectively.

Jan 1, 1999

By E Bouchard March, F Lavoie, B Legare, K Bourassa

Quebec Iron Ore (QIO), a subsidiary of Champion Iron Limited (Champion), completed the restart of the Bloom Lake iron ore mine located in the heart of the Labrador Trough region of Northern Quebec, Canada in February 2018. Prior to its restart, the concentrator flow sheet underwent major upgrades which brought the iron recovery to the highest of all Labrador Trough operations. After two profitable years of production, QIO, supported by Soutex, started to look at technologies to improve its current performance and integrate into its expansion project flow sheet. From the lessons learned while optimising Phase 1, the addition of a scavenger-cleaner processing stage was identified as an improvement opportunity to increase recovery, produce a higher-grade product, and further improve the stability of concentrate quality. In 2019, the NI-43101 feasibility study for the Phase 2 expansion, aiming to double the production of high-grade iron ore concentrate, was published. Based on the metallurgical test work, the hydraulic classifier was selected to perform the scavenger-cleaning duty for its well-established performance and known behaviour at the cleaning step in the Phase 1 plant. To validate laboratory results, a pilot scavenger-cleaning hydraulic classifier was installed in Phase 1. Although the hydraulic classifier was selected for the feasibility study, metallurgical test work performed with the REFLUX® classifier showed interesting potential. It was thus decided to also install a pilot RC300 Reflux classifier at the scavenger-cleaning stage in Phase 1. Despite their apparent great similarities, the metallurgical performance was significantly different, and many dozens of sampling campaigns highlighted the different performance of both pieces of equipment considering the feed material particle size. This article presents the pilot plant results in terms of recovery, selectivity and stability for both the Reflux classifier and the hydraulic classifier operated in a scavenger-cleaner stage at the Bloom Lake iron ore concentrator.

Nov 8, 2021

By A S. Lund

Optimisation of the underground mining production process benefits from informed decision making during the process of explosive rock fragmentation. Selection of the most appropriate bulk explosive products for underground production blasting is an area of endeavour that offers significant economic upside if correctly and thoroughly undertaken. The explosive selection process is facilitated by a clear understanding of:the physical and detonic properties of the alternative explosive options available; the response of different rock masses to these different explosive options; and the importance of maintaining a clear focus on desirable blast outcomes in order to enhance value creation aspects of the mining production process. The level of understanding of these issues is raised through the application of measurement and modelling technology, quantifying the effects of blast design (and implementation) on process outcomes. Homestake Darlot and DynoConsult applied a range of dynamic blast measurement and outcome modelling techniques in order to explore the relationship between rock properties, explosive properties and mining process efficiencies. A campaign of vibration and explosive Velocity of Detonation (VoD) measurement produced feed data for use in vibration and fragmentation modelling during the extraction of one of the major stoping blocks at Darlot Gold Mine. The paper describes the use of these tools and discusses the understanding gained concerning the limitations and capabilities of, and the reconciliation between, a selection of analysis and modelling approaches.

Jan 1, 2001

By H Dehghan Jan Abadi, K Shahriar

The iron ore district of Gol-e-Gohar (GEG) is located 60 km south-west of the city of Sirjan, in the Kerman Province of the Islamic Republic of Iran. Six exploration targets have been identified and iron ore has been mined from one area with dry and wet concentrate products sold. Prior to mining commencing in 1999, the proven reserves were estimated at 265 million tonnes (Mt) in 2004 and 40 Mt of 100 Mt overburden has since been mined. Of the six exploration targets, the largest anomaly in the GEG district is Deposit No 3. This paper discusses economic considerations focusing on mine extraction and construction of a concentration and pelletising plant to process ore from Deposit No 3 of GEG. Planned capacity of 10 Mt product (concentrate and pellet) per year is targeted to commence in 2011, and nominal capacity by 2014. The economical evaluation and analysis is one of the most important stages in the feasibility study of mine development. Financial calculations including the provision of financial resources, operation period revenue, loss and profit statement, cash flow, net cash flow, internal rate of return and net present value have been undertaken as part of the feasibility study. The feasibility study operating plan assumes a large open pit mine containing proven reserves of approximately 250 Mt. The feasibility study assumed an economic return of $80 per tonne iron pellet. The economic study determined that Deposit No 3 of GEG can be economically developed by open pit mining followed by magnetite separation and flotation to generate iron concentrate and pellets.

Jan 1, 2007

By Liu Wenyong, Huang Yucheng, Yang Ba

High-water rapid-solidifying material, called æhigh-water materialÆ, is a new material developed by the authors over many years. The material can solidify nine times its volume of water into solid. The material is a fine kind of binder with special properties. The solidifying body of high-water material with water has quite a high early strength. The compressive strength of the material within three days can reach the same strength as conventional Portland in 28 days. One ton of the material can replace three tons of conventional Portland cement as binder. Some important achievements have been made in application of high-water material. In metal mines, based on the material, a new full-tailing cemented backfill technology has been developed. The characteristic of the new technology is that high-water material is used as binder and full tailing or alluvial sand is used as backfill aggregate. Because of the application of the new technology, major technical problems in backfill technology such as classifying of tailing, dewatering, transportation of pulp, low strength of backfill body, environmental contamination and so on, have been solved.

Jan 1, 1998

By M Nagarajan

Orica Mining Services (Orica) in partnership with Coal and Allied’s Hunter Valley Operations (HVO) has developed a risk management process to maximise mining efficiency whilst controlling vibration and maintaining critical electricity continuity to New South Wales (NSW) electricity grid in the Riverview Pit. The issue is a high tension tower which supplies electricity located within 40 m of mining and blasting activities. The process involved developing an understanding of the relationship between vibration, explosives, geology and the location of the blasting in the geological horizon. From this an optimum methodology for blasting in each region was developed.

Nov 8, 2011

By F M. Weir, M Fowler

The design of excavations in rock must, implicitly or explicitly take into consideration the influence of small- and large-scale geological structures. For most sites the complexity of a fractured rock mass is best captured using a 3D fracture system model based on field data. A discrete fracture network (DFN) approach involves stochastic modelling of the ‘smaller scale’, nondeterministic structures. For slope stability or tunnelling projects DFN modelling provides a valuable geotechnical tool for characterisation of a rock mass and identification of likely failure mechanisms.This paper presents a suite of the DFN modelling undertaken for the design of a large open pit in Australia. The proposed pit is to encounter a 160?m thick, high strength, sheared shale unit, which overlies a crystalline basement. DFN modelling was undertaken separately for both the shale and basement units. While the model inputs and development for each unit are briefly presented, the focus of this paper is on the various applications of the DFN modelling.A key advantage of the DFN approach for design studies is its probabilistic application to structural analyses and results. Multiple realisations of the same model were generated for both the shale and basement units, with the stability analysis carried out on each iteration. The generation of a large number of DFN models and analyses allow assessment of wedge volume, factor of safety and proportion of unstable slope for a range of conditions. The DFN modelling at the case study site was also utilised for a number of other purposes. For example, investigation of likely fault lengths in the shale unit and combined rock mass and defect failure. The development of this tool has been influential in improving our understanding of fracture networks for excavation design.CITATION:Weir, F M and Fowler, M, 2014. Rock mass characterisation and analysis for excavation design – a discrete fracture network approach, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 445–456 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By M Gerards, M Steinberg, T Graham

The quality and quantity of Australia’s secondary deposits, which include tailings streams and tailings dams, are higher than most countries’ primary deposits. In addition, these secondary deposits have already been mined and processed, meaning that the recovery of high-grade product requires low capital and operating costs.The most widely used process for the recovery of these valuable fine and ultra-fine hematite iron particles is the wet high-intensity magnetic separation technique, originally developed by Dr Jones over 55 years ago. Many of the original machines are still working today.The aim of this paper is to demonstrate the capabilities in terms of grade and yield of using sophisticated magnetic separation modules. All results and figures are obtained from test work and design and engineering work with material from the Pilbara. In addition, consideration is given to dewatering of iron ore product and tailings.Two types of tailings have been identified for processing. Firstly, tailings that have already been deposited in a tailings storage facility, and secondly, live tailings streams from an existing wet iron ore beneficiation plant. In both cases, the technical and practical results are shown along with relevant flow sheets and plant layouts. Finally, this paper highlights the total predicted power and water consumption, capital requirements and projected operating expenses.The results show that the operating costs are significantly lower than the mining and processing operations that are required for an equivalent amount of iron ore. The recovery of iron depends on various factors but is within the 30–50 per cent range at an equivalent grade to the mainstream product. Another significant benefit is that the magnetic separation process is water positive, meaning that water is released rather than added in the process.The processing of the Pilbara’s secondary deposits will therefore result in an overall reduction in operating costs, an increase in product yield from a plant, extend the life-of-mine and offer environmental benefits by reducing the tailings footprint and water usage.The quality and quantity of Australia’s secondary iron ore deposits and tailings are such that many other countries would judge these as equivalent to primary deposits. Furthermore, these tailings are already mined, available and liberated to such an extent that the recovery of a valuable product is highly economical in terms of capital expenses and operating expenses.CITATION:Steinberg, M, Graham, T and Gerards, M, 2015. Recovery of iron ore fines and ultrafines from tailings by using wet high-intensity magnetic separation – JONES WHIMS, in Proceedings Iron Ore 2015, pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By D Michaelsen, S Miller

The Grasberg Mine is a copper and gold open pit mine operated by PT Freeport Indonesia (PTFI) and located in the high equatorial mountains of the Indonesian province of Papua. The climate is alpine/subalpine with little seasonal variation in temperature or rainfall. The daily average temperature ranges from about 2¦C to 14¦C and the annual rainfall in the vicinity of the mine and overburden stockpiles is about 4000 mm to 5000 mm. Mining of the Grasberg open pit will continue until 2014 at which time approximately 2750 Mt of overburden will have been produced. Current overburden production rates are 200 Mt per annum. The current mill rate is 230 000 t/day from the Grasberg pit (190 000 t/day) and the underground operations (40 000 t/day). The acid rock drainage (ARD) issues associated with overburden from the Grasberg operations were identified early in the mining operation. Almost all overburden placed to date has been Potentially Acid Forming (PAF). Laboratory testing has identified four main overburden types: limestone and non-acid forming (Green waste), PAF low capacity (Blue waste) and PAF high capacity (Red waste), and Heavy Sulfide Zone (HSZ), which contains greater than 20 per cent pyrite. Waste type block modelling indicates that at least 30 per cent of the overburden production from 2003 to the end of Grasberg pit operations will be limestone. Strategies are being developed to maximise the beneficial use of limestone through strategic blending and placement for ARD mitigation and control.

Jan 1, 2003

By C DahnTr-Lindqvist

The Kiruna mine produced about 19 Mt processed iron ore in 1999 using sublevel caving. General failure in the hangingwall has been widely studied and its mechanism is rather well understood. Failure in the footwall is more recent and not perfectly explained. Plane shear failure and Hoek and BrayÆs circular failure charts were successfully used to match the first surveyed failure surfaces. The footwall is not free yet but covered by a caved waste rock abutment whose exact behaviour is poorly known. Based on new field data and numerical models (FLAC), the following paper presents recent improvements in understanding the Kiruna mineÆs footwall failure process.

Jan 1, 2000

By P G. Doig

Recent drops in commodity prices and economic uncertainty have seen many businesses re-evaluate their operational expenditure to ensure mine profitability. The high capital and operational cost of truck and digger fleets has resulted in loading and hauling of material being a significant proportion of a mine’s expenses (Nel, Kizil and Knights, 2011), thus it is often one of the first areas to be considered for cost reduction. If an operation requires additional trucks to maintain or improve productivity, a robust justification is crucial due to the expenditure involved.Mining schedules form the basis of productivity and cost estimations for mining operations and therefore must have a significant level of confidence with regards to achievable quantities and rates. Traditionally, a mining schedule is produced without detailed consideration of the trucking capacity or requirements. Although some mine planning software incorporates haulage predictions into schedules, most cannot model the dynamic nature of dumping and haulage. Previous studies have shown that it is necessary to have detailed haulage analysis instead of the traditional mining block centroid to dump block centroid methods for more realistic mining schedules and cost estimation (Doig and Kizil, 2013).Recent developments in software have allowed the dynamic integration of haulage analysis with mining schedules. Engineers can now create mining schedules in conjunction with dumping schedules, allowing mining schedules to reflect the restrictions created by the number of available trucks, combined with dynamic consideration of available in-pit and out-of-pit dumping locations.A study has been completed producing a mining schedule in conjunction with a dumping schedule and haulage analysis. Multiple schedules were run with various haulage strategies (including minimising rehabilitation liability) and truck availability to identify the impacts on coal production, and hence revenue. A financial analysis was then completed where a net present value (NPV) was calculated for each scenario. The study showed that trucking shortfalls can significantly impact mining schedules and cost estimations, both in terms of cost as well as revenue lost when trucks cannot maintain forecast production rates, thus dumping schedules and haulage analysis should be completed simultaneously. If dumping and haulage is not considered when planning the mining schedule, a mining business is ignorant to the impacts trucking has on the mine production, closure risk and profitability.CITATION:Doig, P G, 2014. Value impacts of truck limited scheduling, in Proceedings Life-of-Mine 2014 , pp 513–524 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By T J. Sullivan, H Pinkster, G Swarbrick

From 2002 to 2006, longwall mining was undertaken directly beneath the Cataract Tunnel, which is a 100-year-old, heritage-listed tunnel in Hawkesbury Sandstone responsible for delivering 20 per cent of Sydney’s annual water supply. At one location, undermining resulted in movement of at least 350 mm along a known fault that transects the tunnel. During this movement, the continued operation of the tunnel was ensured through a careful system of planning, monitoring and management.Of key importance to the success of the operation was the use of advanced numerical modelling to guide operations at all levels, including feasibility assessment, pre-mine mitigation works, monitoring design, operation performance and post-mining condition. This allowed many aspects of the potential impacts to be explored, including joint movements, rock mass deformations and changes in permeability. A key challenge was to successfully model near-field influences on adverse geological structure due to very far-field effects. This paper explains the model’s conceptual development, calibration, performance and limitations.Modelling provided the confidence to manage the impacts of large mining-induced movement on key infrastructure and ultimately predicted fault movement accurately. The fault movement remains one of the highest ever recorded due to mine subsidence.CITATION:Swarbrick, G, Sullivan, T J and Pinkster, H, 2014. Longwall mining beneath critical infrastructure – prediction versus performance of the Cataract Tunnel, New South Wales, Australia, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 157–166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By P Myers, T Elkington, S Wonday

Sierra Rutile LimitedÆs (SRL) heavy mineral sand mining operation in Sierra Leone, West Africa, is embarking on a new phase of its life. After confronting many challenges during the 1990s and 2000s, SRL is embarking on a strategy of growth to recover maximum value from the mine over the rest of its life. Sophisticated linear programming techniques have been used to develop an optimum strategy for extracting SRLÆs many known deposits of economic grade, while considering options for expansion and for a variety of mining and processing methods and combinations. CITATION:Myers, P, Elkington, T and Wonday, S, 2012. Strategic optimisation at Sierra Rutile - A case study in maximising project value, in Proceedings Project Evaluation 2012 , pp 59-66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

The underground storage of LPG and other hydrocarbons is in current commercial use in Northern Hemisphere countries in Europe, Asia and the USA.Elgas Pty Ltd, a 50 per cent joint venture between AGL and BOC, embarked on a worldwide feasibility investigation in 1989 to establish the viability of constructing an underground LPG storage facility in Sydney, Australia, the first of its kind in the country. Elgas recognised that with the limited 19 000 tonnes of storage capacity at Port Botany and the limitations imposed by use of small coastal ships (up to 10 000 tonnes capacity), a larger storage facility was required to utilise higher capacity ships from more remote sources such as the North West shelf and overseas. This would achieve security of supply in high demand periods and economies of scale. The underground option also provides improvements to safety and environmental standards.

Jan 1, 1999

By R Yong, A McEwan, D G. Miljak, D Milinkovic, A Curtain, P J. Coghill, R Stefulj, B Lovric, G Roberts

The CSIRO has pioneered the development and use of certain classes of magnetic resonance (MR) for mining applications. The MR technique is a radio frequency-based spectroscopy that provides highly quantitative measurement of selected ore minerals. MR has many inherent advantages for bulk sensing in mining applications, including deep sensing penetration into most bulk ores with the use of non-contact sensors that are robust and tolerant of demanding mine conditions. The highly discriminating nature of the technique also provides the very desirable attribute of robust and simple calibration, that can often be performed prior to sensor installation. Rapid sensing (within seconds) at very low grade (few hundred ppm Cu) has been demonstrated, as well as sensing at high tonnage rate. Besides sorting applications, MR may also be applied to preconcentration applications involving very large volume sensing including: (i) haul truck sensing using portal arrangements, where truck destination assignment may be dynamically determined based on the truck grade, (ii) in-pit gantries used for loading trucks that may similarly be equipped with sensors for truck assignment and (iii) deep mine bench sensing, recently progressed through a CRC ORE project, where local bench grade is determined at the few-metre lateral scale and at depth prior to blasting, to aid selective blasting and ore extraction. MR sensor prototypes have been developed for each of these applications and have been tested in laboratory or limited field conditions. To inform the value proposition for truck or bench sensing, initial analysis of truck assignment improvement based on an analysis of in-situ mine bench grade has been performed for a porphyry style deposit. The prototype sensors, preliminary results and future technology development and objectives will be described.

Nov 10, 2020

By D Wimpenny

The Bogong Power Development Project in Victoria, Australia involved the construction of a 15 m long mass concrete plug up to 9 m in diameter within the head race tunnel. The plug is critical to theperformance of the scheme as it permanently seals the head race tunnel under approximately 300 m head of water.The location of the plug in the headrace tunnel was determined by a programme of in situ rock stress testing using both hydrofracturing and over coring stress testing methods.In recognition of the importance of the plug, the Head Contract specification requires that its temperature during hydration be controlled using an embedded cooling system. In addition, contact grouting and curtain grouting around the plug cannot commence until thermal contraction was substantially complete.This paper describes the use of bespoke fi nite element software to model the temperature rise in the plug and design mitigation measures to control temperature rise in the plug. These measures include restricting the concrete placing temperature to 10°C, incorporating 39 per cent fly ash in the concrete and installing embedded cooling circuits.Site trials were undertaken to calibrate the model for the proposed concrete mix. The cooling system comprised 25 mm ID pipes forming twelve separate circuits that fed 7°C water from a single chiller unit. The cooling system reduced the peak temperature in the plug to approximately 30°C and the associated risk of early-cracking. The time before contact grouting could commence was shortened to less than two weeks from casting.

Mar 8, 2011

By S Ravn

Under platform exhaust (UPE) systems are often designed into metro stations as a means of removing heat generated by trains as they come to a halt in the platform. These systems are designed to extract heat from the brakes and brake resistors directly at the source in order to capture as much heat as possible before it can enter the public areas of the station, or contribute to the temperature build-up in the tunnels. Due to space requirements for the associated duct and air handling units, the UPE plays a significant role in the geometric design of the platform and station as a whole.In recent years questions have arisen as to the effectiveness of UPE systems. However, very little data is available for designers to use when making important decisions on the station designs for new metro systems. This is important as significant savings could be achieved by omitting or re-designing these systems for new build stations; not only due to the capital costs of space provision for the duct itself but also due to the associated operation and maintenance cost of the UPE system.This paper will present recent measurements of the UPE system of the Copenhagen metro together with one-dimensional (1D) simulations, looking at typical dispersion of heat into the station plenum box and air exchange through draught relief shafts as the train enters the station in order to evaluate the effectiveness of the UPE system. The aim of this paper is to disseminate the results of measurements and analysis to increase awareness of the issue and to provide discussion relevant to designers in their evaluation of heat removal systems in new build station designs.

Mar 8, 2011

By Skinner A. J, Thoman B. C

The general structure of microprocessors and their method of use is described, and de- tails given of their application in two parti- cular examples of instrumentation for mineral concentrators. One is in a pulp density gauge, and using this example, the way in which a microprocessor-based unit can be made to be self-calibrating is described. The other is in an on-stream analysis detector for uranium in solvent, where a microprocessor is used to re- place a mini-computer.

Jan 1, 1977