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By J. A. Cole

The mill project at Lone Tree was commissioned in October, 1993, followed by the commissioning of the autoclave pressure oxidation circuit in February, 1994. Discussion of the first year of milling operations at Lone Tree is presented. The mill is currently operating above the design rate of 2,267 mt/d (2,500 st/d). Both phases of the start-up were essentially trouble free. The few problems that were encountered and the respective solutions are addressed.

Jan 1, 1995

By Francis Vanbellen

In Union Minière's Hoboken smelter and refinery for complex non-ferrous materials, the treatment of recycling products, containing precious metals, occupies a dominant place. For all feed materials, the first step, prior to their treatment, is to classify them in order toselect an accurate and economical procedure for sampling as well as to dispatch them to the optimal process scheme. More than 150 different procedures for sampling are commonly used. The most important ones are briefly discussed in the paper. Precious metals bearing recycling materials vary widely with respect to their physical aspect, their chemical composition and the value of their precious metal content. All these parameters are taken into consideration to select the most appropriate process among the multiple possibilities of Union Minière's flexible integrated flow-sheet. Different stages of the operations as well as the main flow-sheets are described.

Jan 1, 1995

By Richard P. Killmeyer, Carl P. Maronde, W. W. Wen, Peter J. Suardini

Under a cost-shared Department of Energy contract, awarded as part of the Coal Preparation Program&apos;s High Efficiency Preparation subprogram, Custom Coals International will be installing and testing a 227 kglhr micronized-magnetite cycloning circuit in PETC&apos;s Coal Preparation Process Research Facility. The project includes the design, construction, testing, and decommissioning of a fully integrated circuit complete with feed coal classification to remove the minus-30-micron material, dense-medium cycloning of the 300 by 30 micron feed coal using micronized magnetite (<10 microns), and medium recovery via drain & rinse screening and various stages and types of magnetic separation. This paper will describe the micronized-magnetite beneficiation technology and the scope of work for this project including an update on the status of the project, the circuit, and the proposed test plan.

Jan 1, 1995

By B. Nyman

A lot of work is in progress to improve copper recovery by leaching-solvent extraction-electrowinning (L-SX-EW). At Outokumpu the focus of attention is on SX equipment development as a result of which a new mixing-settling technology, the Vertical Smooth Flow (VSF) has been introduced. Using helical stirrers in the VSF mixers a more gentle and uniform contacting can be obtained than in the mixing compartments of the low-profile design. The benefits of Outokumpu&apos;s new approach are an essential decrease in organic losses and in aqueous in organic entrainments. Separate pumping using a smoothly pre-contacting "Dispersion Overflow Pump" (DOP) is a key feature of the VSF design. The scale-up of this pump as well as the VSF mixers are shown to follow simple mathematical relationships which also have been confirmed by full scale experiments.

Jan 1, 1995

The pile inspector is a critical element in the quality control process necessary for a successful pile installation project. This guide is intended to provide the inspector with a basic understanding of only one of the many components of this process - the pile driving hammer. Pile driving hammers are used to install both bearing piles for structure foundations and sheet piles (and soldier piles) as used in retaining structures. In a single document, this guide offers a general presentation of the operation of the more common types of hammers the inspector is likely to encounter. It should make the information in the contractor&apos;s hammer submittal for the project more understandable. It should also provide an appreciation for the importance of a properly operating pile hammer. Prior to the start of most pile driving operations, the contractor will normally furnish a submittal to the engineer giving the specific pile driving equipment that he intends to use on the job. This submittal should include the make, model, and type of the intended pile driving hammer or hammers and their operating characteristics such as ram weight, rated energy, operating speed, external power requirements and, other pertinent information. Frequently, the operating characteristics are provided in the form of the manufacturer&apos;s specification sheet. The engineer will review this information and when he is satisfied, approve it and pass it on to the inspector. The driving criteria will have been determined by the engineer or others (the geotechnical engineer, consulting engineer, contractor, etc.) from the results of static analysis (for minimum penetration), driving during a test pile installation, Wave Equation analysis, dynamic formula, pile instrumentation during driving, static load test, or a combination of these or other appropriate analyses. The driving criteria can be a minimum penetration of driven pile length (embedded length), or a minimum (or maximum) blow count per unit of penetration. The pile inspector should become familiar with this information prior to the start of the job and should understand or seek help to comprehend the terminology and intent of each specification.

Jan 1, 1995

Optimal drill and blast design is a process often neglected by many underground hard rock mines. This is even more important to the new mine where ring designs need to be implemented and refined in a short period of time. In today&apos;s environment where more and more mining is being carried out by contract specialists it is the co-operation between a principal and contractor, who are working towards a common goal, that achieves the highest quality end result. The development of drill and blast designs that cause minimal damage to the mine infrastructure is particularly important to Northparke&apos;s E26 Block Cave Mine, as it consists of a single extraction level which must survive intact for the life of the mine. The advanced undercut mining method implemented at Northparkes is fired in a sequence which protects the mine development from potentially damaging abutment stress. This paper details how blast designs will be optimised and sequenced to satisfy the conflicting objectives of maximum rock breakage inside the drill pattern and minimum rock damage outside the pattern.

Jan 1, 1995

By S. B. Patton, T. Novak

To fully utilize a ventilation simulator as a planning and production tool, the network database must keep pace with mining progress. By using AutoCAD&apos;s™ attribute-definition function, the branch data and node coordinates can be stored as part of the branch-diagram file and updated with the drawing. Attributes are drawing entities that contain text which can he extracted in a standard spreadsheet format or as an ASCII text file. The data can be subsequently loaded into a ventilation simulator. This paper presents the methodology for using AutoCAD&apos;s™ attribute feature in a ventilation simulation format.

Jan 1, 1995

By Jacek Paraszczak, Stefan Planeta

"RésuméDans la première partie de cet article on discute Ie contexte technico-économique de l&apos;usage des foreuses à l&apos;eau sur béquille dans des mines sud-africaines. Par la suite on présente les résultats d&apos;une étude comparative du forage avec les foreuses à l&apos;huile et à l&apos;eau par rapport aux foreuses pneumatiques. La performance des foreuses est discutée sous les deux aspects: l&apos;aspect technique concernant Ie taux de pénetration et la quantité d&apos;eau rejetee dans les galeries et l&apos;aspect de fa santé et sécurité au travail, et plus particuliérement, les niveaux de bruit et de vibrations ainsi que Ie brouillard de l&apos;huile. On conclut par l&apos;évaluation du potentiel de forage à I&apos;aide des foreuses hydrauliques dans Ie contexte canadien.AbstractIn the first part of this paper the technical and economical aspects of water-powered drilling are discussed. This technology, originally employed in South Africa, received some interest from Canadian mine operators. In this context a comparative experimental study of pneumatic and hydraulic (oil- and water-powered) jackleg drills has been realized. The performance of the drills is compared and the results reviewed with regards to technical aspects (penetration rate, amount of water spilled) as well as health and safety considerations (noise and vibration level, presence of oil mist). The potential for application of hydraulic jackleg drill is discussed."

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today&apos;s competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

The title of my presentation is `Nursing One&apos;s Resources&apos;, words that fit a young organisation like Ross Mining and words we had to apply to reach our current level as a company. To get to where we are, we had to nurse, foster and treat carefully all our available resources in the widest sense of the word, namely: ò a stock or supply that can be drawn upon (funds, mineral resources, human resources); ò the means available to achieve an end; ò skills in devising expedients; and ò practical ingenuity. I do not claim that Ross Mining is now the perfect mining company. However, we have become a profitable, dividend- paying, gold mining and exploration company which is to our knowledge, currently the cheapest gold producer on the Australian continent. Nursing our resources got us where we are and will guide us in our future development. The words `nursing one&apos;s resources&apos; are I feel particularly applicable to mining-as I like to argue that the extractive mining industry has a social responsibility to optimise the metal output and value from each orebody which is being exploited, and preferably leave no metal behind. Likewise, a modem company cannot survive into the future without maximising and optimising its human resource potential. In this presentation I would like to present a number of actual examples of nursing one&apos;s physical and human resources. Before I do that, I will give a brief background to Ross Mining. Ross Mining NL is a young Queensland-based company that gained its stock exchange listing in September 1987 and that poured its first gold in 1989 from its own developed Belyando Mine, located in Central Queensland. We have now reached the stage of a medium-size gold producer, producing approximately 70 000 ounces of gold per year, mainly from the Yandan Gold Mine, also in Central Queensland. Our production is set to increase to over 100 000 ounces in the near future. Recent increases in our resource base have secured us a future of ten to 15 years. As a young, newly listed company, we faced all the dangers that most new small floats do as a new entrant into an established industry. However, one advantage of being young and perhaps naive, is summed up by the following Zen Buddist saying: In the beginner&apos;s mind there are many possibilities, in the expert&apos;s mind there are few. A mining company&apos;s main assets are the sum of its resource base and the skills and talents of its people. Attempting to optimise both the physical and human resources within the company has been to-date the key to our success. The first example I would like to present is linked to the exploitation of the Belyando Gold Mine in Central Queensland.

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today&apos;s competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By Samuel A. Rasmussen

Lead anodes are used in commercial copper electrowinning operations, yet there is no method to calculate anode life. To be discussed in this paper are operating characteristics of rolled plate (Pb,Sn,Ca) alloy anodes at Morenci&apos;s electrowinning tankhouse along with fundamental operating conditions and how the anode reacts to these conditions. These include anode maintenance, electrolyte temperature and viscosity, cobalt concentration, and manganese concentration. Also to be discussed are anode substrate characteristics under normal operating conditions and how the corrosion rate is affected by changes in operating conditions.

Jan 1, 1995

By Gilbert A. Bonforte, Hugh P. Caspe, Tracy K. Lundin

The Narragansett Bay Commission (NBC) Combined Sewer Overflow Abatement Program is a major effort to address and mitigate discharges from combined sewer overflows in the Providence, Rhode Island area. The proposed system consists of three deep rock tunnel segments totaling 17.8 km (11.1 miles) in length that will provide 860,000 cu m (227 million gal) of storage at depths up to 99m (325 ft). This paper discusses 13.5 km (8.4 miles) of 6.64m (21.8 ft) finished diameter tunnel, four construction shafts, 19 dropshafts and one large diameter pump station shaft tapered from 1 5.2m (50 ft) at the surface to 27.4m (90 ft) at depth. All facilities are in preliminary design.

Jan 1, 1995

By Terrence Chatwin, Michael Sweeney, Steve Accardo

Sutter Gold Venture excavated an exploration decline into a mineralized zone in the Sutter Creek gold mining district. Delays in obtaining the conditional-use permit resulted in 7 to 10 million gallons of water accumulation in the decline containing elevated dissolved arsenic. Sutter received a permit to land apply the water after reducing the arsenic concentration to 0.05 mg/L. Initially the water was treated by co- precipitation arsenic with ferric hydroxide. Operational difficulties of this treatment system resulted in Sutter pursuing alternative treatment methods. The activated alumina adsorpting was selected due to its flexibility and ease of operation. Operating and maintenance data and costs will be presented.

Jan 1, 1995

By K. R. Weller

In recent years, a variety of new or substantially modified grinding machines have been offered to the mining industry with claims of improved performance relative to standard grinding machines especially rod and ball mills. The incentive for developing such new machines is high, because costs associated with grinding are a very substantial part of the total costs of processing run-of-mine ore, and gold ores are no exception in this regard. The incentive is also high because of the very low conversion of input energy to comminution energy in most tumbling mills. If the most energy-efficient means of mechanical size reduction is slow compression of single particles, then this energy amounts to only about 3% of that used in tumbling mills. It would seem, therefore, that there is a huge potential to do better. This paper examines three types of grinding machine for which claims of higher energy utilisation ( amongst other beneficial claims) have been made, namely the high pressure grinding rolls, the vibrating drum mill and various styles of stirred mill. It presents evidence concerning the claims, examines the range of particle size and particle size reduction over which benefits might reasonably be expected to accrue, discusses the major issues in contention and briefly describes the research the CSIRO Division of Minerals has in progress, both independently and collaboratively, the latter mainly with the Julius Kruttschnitt Mineral Research Centre (JKMRC) via the Cooperative Research Centre for Mining Technology and Equipment (CMTE) and the Australian Mineral Industries Research Association (AMIRA). There are many criteria which may be chosen to assess relative performance of grinding machines. Those used below are:

Jan 1, 1995

By John Batty, Rennie Stallknecht, Dave Dew, Rennie Marais

GENCOR was contracted by Lonrho Plc of London to design a treatment plant for the benificiation of ores from the Amantaytau Goldfields in Uzbekistan (CIS). The testwork required for determining the design parameters was conducted at GENCOR Process Research in Randburg South Africa, on large bulk samples of ore shipped from the CIS. The initial milling and flotation testwork was designed to both optimise the conditions for maximum gold recovery, and to provide flotation concentrate for subsequent testwork. The concentrate produced was fed to a pilot scale BIOX® plant, and at the client's request a portion was shipped to specialists in roasting and pressure oxidation technology for comparison. Besides the testwork conducted at the GENCOR Process Research Laboratories in South Africa, the client also requested that the testwork be repeated at the Ingichki Research centre in Uzbekistan to demonstrate to their CIS joint venture partners that the results obtained in South Africa are reproducible and to demonstrate the ease of operation of a BIOX® plant. Pilot scale equipment was air freighted to Ingichki where the results of the testwork obtained in South Africa were successfully duplicated. BIOX® technology was shown to achieve higher gold recoveries than either roasting, whole ore roasting or pressure oxidation.

Jan 1, 1995

By David Martin Menne

In a small tank, slurry is passed through the high shear impeller zone with small time intervals, and a large proportion is regularly exposed to air at the surface, and at relatively high shear rates. This accounts for significant differences in the performance of large and small tanks. It is preferable to derive data where possible directly from an operating plant rather than applying data generated in small tanks where allowances must be estimated for the above differences [and where slurry aging and often substantial cooling compared to hot freshly milled ore further distorts results]. Various measurements have shown that many gold slurries can suffer extreme variability, as streamers of bypassing material or boules of hold-up periodically condstitute the instantaneous discharge from a tank - the relatively high Yield stress of slurries [around 1 to 10 Pa] causes very incomplete homogenization of slurry in any tank, the worse the larger the tank and the more viscous the slurry. To provide a background for this subject, this monograph presents leach and adsorption models based on the fundamental physics and chemistry of these processes, and includes quantitative discussions of factors which can lead to deviations on scale-up. The Throughflow model which avoids the need for such alowances is then presented, as well as a Computer Programme applying this model, and which allows direct calculation of the effects of:

Jan 1, 1995

By A. J. Lewis, P. J. Hutcheson, M. E. Robertson, P. A. Moir, K. M. Barfoot

With the content of gold and platinum in the vast majority of ore deposits typically averaging 6 parts per million and less, the accurate and precise measurement of these metals in samples of ore and mining process streams has proven very difficult to achieve by modem spectroscopic analytical techniques. Largely because no other technique has proven suitable, the basic fire assay process has become the accepted international standard for these metals. Fire assay, however, suffers a number of disadvan­tages in the modem, competitive, high technology, and increas­ingly environmentally aware world. It is a labour intensive technique that is difficult to automate, and requires high levels of skill to ensure accuracy and consistency of results. Potentially hazardous chemical reagents are employed, of which, lead, in particular, can be a serious source of contamination to both personnel and the environment if not effectively controlled. Other dangerous elements, such as mercury and arsenic, liberated in high energy furnace operations, are further sources of possible health and pollution hazards. n contrast, the energy dispersive K X-ray fluorescence (K­XRF) technique devised by K X Technology Ltd overcomes many of the technical constraints of conventional low energy X­ray analysis, and has the potential to revolutionise assay opera­tions in precious metal mining. The technology is simply automated, requires basic operator skills, uses no chemicals, consumes less than 20kW, and is capable of detecting gold and platinum to an accuracy of O .1 parts per million by mass. The new third generation design of AZTEC laboratory instrument, released in 1994, is the result of significant technical development. Capable of analysing over 1200 samples per day, and developed primarily for grade control sampling, its applica­tions have spread to gold ore accounting from on-line conveyor belt sampling; screening of exploration samples; measurement of gold in carbon granules for Carbon-in-Pulp process control; and for conducting rapid checks to support key managemen decisions. The economic, rapid, and non destructive analysis ofup to 80g of ore for large numbers of samples, reduces sampling and sub-sampling errors, and provides improved grade estimates for ore bodies. When interfaced to a LIMS, laboratory automation and cost-savings can be further enhanced. The AZTEC design is also being modified for the analysis of platinum. The GOLDSTREAM on-line analysis system is an important new application of K-XRF to the continuous monitoring of process streams in gold ( or platinum) plants and mills. Integrat­ing the technologies of K-XRF to measure total gold, and dissolved gold spectroscopy to measure gold in solution, the insoluble fraction of gold can be deduced, and the effectiveness of the extraction process determined. Slurries are sampled automatically from selected points of the plant and pumped to the system for analysis. The information produced forms the basis for plant control and optimisation.

Jan 1, 1995

By P. J. Hyde

Cyanide is a significant contributor to the cost of producing gold. Any reduction in consumption that can be achieved through more reliable measurement and/or more efficient management of dosing rates can have a significant financial impact. An automated analyser, by its mechanical nature, is not prone to the variations of human operators, particularly notice­able from shift to shift. Reducing the standard deviation of the measurement (ie, reducing noise ), the automated measurement will give the metallurgist a truer picture of the underlying patterns of usage. The combination of automated analysis with on-line operation and a control loop provides timely information that is efficiently utilised in the management of the plant. Until the release of the Chemtronics On-Line Cyanide Analyser (OTA3000) about 12 months ago, the Australian experience with automated analysers (especially on-line) had been substantially negative. Since its release, the Chemtronics instrument has outperformed both manual titrations and other automated instruments, gaining an enviable reputation for accuracy and reliability in the process. The instrument is built around the technique ofpotentiomet­ric titrations, in which the potential of an indicator electrode is measured as a function of the volume oftitrant that is added to the sample. As the cyanide in the sample is depleted, the potential on the indicator electrode changes rapidly, producing a typical sigmoidal curve. The OTA3000 takes the first differ­ential of the curve, identifies the apex of the peak as the endpoint and reports the result in parts per million of sodium cyanide. The OTA3000 accepts the peak as valid only if it exceeds a certain minimum height. That minimum height is a programma­ble parameter and is used to optimise the relationship between sensitivity and the rejection of spurious peaks. The instrument will track cyanide trends through both positive and negative slopes of any magnitude, but it will provide a warning if it the slope becomes excessive, not because it affects the instrument but because it means that something unusual is occurring in the tanks. There are a limited number of conditions under which the instrument will produce a result of zero. In these cases the OTA3000 holds any output lines at the last valid result while it repeats the titration. This feature was incorporated for reasons of stability in a feedback loop.

Jan 1, 1995

By P. B. Hearse, R. L. Flood

TQM is a term of which most metallurgists have heard and a system of which some have had first hand experience. This paper is designed to encourage further thinking on TQM and how it can effect your organisation. Consideration of organisational culture and objectives are a prime pre-requisite when planning for the implementation of TQM. It is argued that there is no "brand" of quality culture of TQM which can be applied en masse to the mining industry. Definitions ofTQM are proposed, and the essence ofTQM as being about increasing customer service, improving the quality of goods and services, and involving people in their work is discussed, in conjunction with the concept of Customer as applied to the metallurgical industry and TQM. The integration of TQM into Quality Accreditation Stan­dards is then discussed. Finally, examples of the benefits that may be achieved with Implementation ofTQM into metallurgical and operations groups is presented, along with an analysis of the difficulties of implementation into our businesses and operations.

Jan 1, 1995