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By D Reid, J Vinod, M Rahman, A Fourie, T Vo, J Ayala, A Russell

This paper reports on an industry and Australian Research Council funded research project, TAILLIQ, that is a joint initiative between four Australian Universities. The paper discusses the accuracy with which the critical void ratio can be determined for a given tailings; it does this by presenting the results from a ‘round robin’ study in which 18 geotechnical laboratories around the world participated, testing the same tailings (sampled from a gold mine in Western Australia). The results were variable, although a reasonable number were very similar, as described in the paper. The paper provides additional test data for sandy silt gold tailings recovered from a sponsor’s site in Australia, including preliminary calibration chamber test data, results from direct simple shear tests and characterisation tests to determine unsaturated geotechnical properties.

Jul 1, 2021

By H. W. Hitzrot

THE new 4800-ton fine-grinding plant at the Hollinger Consolidated Gold Mines property at Timmins, in the Porcupine district of northern Ontario, went into operation in November 1937, and represents the culmination of an experimental program. The plant is a moderately low rectangular building of hollow tile on a steel frame, large enough to house four 7 by 15-ft. ball mills, with a 12 by 27-ft. classifier beside each mill. At one end is space for the addi-tion of another mill and classifier or a mill and classifier for the regrinding of table concentrates. This regrinding is now done in the old grinding department of the main mill building. Also within the new building are the four 6-in. sand pumps for lifting the product from the low-dis-charge ball mills up to the classifier feed launders and the containers and appurtenances of a complete dust-collecting system. Together with the usual overhead crane, these constitute the major units of equipment within the new plant. The location is at the lower end of the main mill buildings toward the old tailings pond, now so neatly leveled off and sodded to rival the very best of our own W.P.A. projects. Close by the new grinding plant is a large dome-shaped structure-the new fine-ore bin designed and built by Mr. Longmore and the Hollinger milling and engineering staffs. There are four separate automatically loaded inclined belt conveyors leading up from the bottom of the bin to the grinding plant. Each belt is equipped with a recording weightometer, in the grinding building. The whole structure and the machinery within it give the impression of permanence and a carefully integrated design with close attention to details, giving the operators every advantage for consistently good work.

Jan 1, 1939

By H. W. Hitzrot

THE new 4800-ton fine-grinding plant at the Hollinger Consolidated Gold Mines property at Timmins, in the Porcupine district of northern Ontario, went into operation in November 1937, and represents the culmination of an experimental program. The plant is a moderately low rectangular building of hollow tile on a steel frame, large enough to house four 7 by 15-ft. ball mills, with a 12 by 27-ft. classifier beside each mill. At one end is space for the addition of another mill and classifier or a mill and classifier for the regrinding of table concentrates. This regrinding is now done in the old grinding department of the main mill building. Also within the new building are the four 6-in. sand pumps for lifting the product from the low-dis- charge ball mills up to the classifier feed launders and the containers and appurtenances of a complete dust-collecting system. Together with the usual overhead crane, these constitute the major units of equipment within the new plant. The location is at the lower end of the main mill buildings toward the old tailings pond, now so neatly leveled off and sodded to rival the very best of our own W.P.A. projects. Close by the new grinding plant is a large dome-shaped structure-the new fine-ore bin designed arid built by Mr. Longmore and the Hollinger milling and engineering staffs. There are four separate automatically loaded inclined belt conveyors leading up from the bottom of the bin to the grinding plant. Each belt is equipped with a recording weightometer, in the grinding building. The whole structure and the machinery within it give the impression of permanence and a carefully integrated design with close attention to details, giving the operators every advantage for consistently good work. The many ideas and opinions behind this achievement were all ably organized and executed by the Hollinger milling and engineering staffs, anti not a few were directly initiated by them. Excellent cooperation was afforded by the Hollinger staff to the engineers helping to conduct the grinding and classification test program. It was the author's privilege

Jan 1, 1939

By M Bird, B Oats, M Sganzerla

Mining operations are continually aiming to reduce operating costs to improve plant profitability. One way in which the Cannington operation sought to achieve this was by increasing the wear life and reducing the energy consumption of their flotation mechanisms. This was made possible using Outotec’s FloatForce mechanism. The FloatForce mechanism has been developed by Outotec over a six year period involving both CFD modelling and rigorous site testing. FloatForce delivers improved air dispersion and cell agitation efficiency; as such it can be operated at lower rotor tip speeds when compared to Outotec’s previous mechanism.Cannington trialled three FloatForce mechanisms in a train of ten OK38 zinc roughers. The mechanisms’ rotational speed was reduced by 10% compared to the previously installed MultiMix mechanisms. The purpose of the trial was to quantify the energy saving and assess whether there was any reduction in plant metallurgical performance.The trial was successful with FloatForce delivering a 17% reduction in power, an improvement in wear and improved recovery. Analysis of pre and post-installation metallurgical accounting data showed the following:The FloatForce installation resulted in a recovery increase of zinc to zinc final concentrate of 0.4 – 4.0%*The FloatForce installation resulted in a recovery increase of lead to zinc final concentrate of 0.0 – 0.3%*There was no statistically significant change in silver recovery to zinc final concentrate that can be attributed to FloatForce**95% confidence interval (CI) using multiple linear regression models.The Cannington operation is now in the process of further optimizing its power consumption and wear savings by changing the remaining OK38 zinc and lead rougher float cells to FloatForce mechanisms.CITATION:Bird, M, Oats, B and Sganzerla, M, 2015. Improvements in flotation cell maintenance, power consumption and operation at South32 Cannington, in Proceedings MetPlant 2015, pp 230–245 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By J. L. Arola

Since start-up of fluxed pellet production in August: 1987, the Minorca Mine has made a number of process changes to improve pellet quality and productivity. Quality improvements include: 1. Installation of a contraction t:ester. 2. Installation of on-line calcium and silica analyzers. 3. Process autocation changes. Productivity improvements include: 1. A second fluxstone storage bin and feeder. 2. A new vacuum pump and disc filter. 3. A filter aid addition system. 4. Enclosing the filter cake reclaim feeder. 5. A new grate bar cleaner.

Jan 1, 1989

By Allen W. Hatheway, John A. Albritton, Lloyd B. Underwood

Missouri River Division (FORD), U.S. Army Corps of Engineers (COE), has completed (October 1982) a study for the U.S. Air Force Ballistic Missile Office, in which desireable and needed changes in contracting methods for underground construction were identified. Due to the importance of geotechnical considerations in such construction, a good number of the resulting recommendations relate to geotechnical considerations. Corps contracts have traditionally served as models for contract documentation by public agencies and in private enterprise. Several standard features of present-day contracting methods were Corps innovations. Corps officials are generally in agreement with the recommendations of the Better Contracting reports published by the U.S. National Research Council (NAS/NRC), through its U.S. National Committee on Tunneling Technology (USNCTT). However, the findings of the 1982 MRD study indicate that additional changes are warranted for underground construction contracting methods; changes that deal specifically with site geological conditions, both known and to be reasonably anticipated, as well as with their associated impacts on construction. The 1982 MRD report identifies the need for nine specific improvements in geotechnical aspects of contracting; improvements based on recognition of geological conditions.

Jan 1, 1983

By Linda Duncan, Trevor Yeomans, Chris Potorieko, Michael Fullam

"NVI Mining’s Myra Falls Operation is a 4,000 mtpd copper/zinc flotation circuit with by product gold of ~28,000 ounces per year. Gold recovery has historically averaged 40-55%, however, a portion of this was recovered in the zinc concentrate and received poor payment. Two Knelson CD-30 Concentrators have been operating in the grinding circuit since 1992, with gravity recovery averaging about 2-5% over that time period.The Myra Falls gravity circuit was one of the very first hard rock mining installations operating in the world with automated Knelsons. The mine has employed a unique and unusual upgrading method for the Knelson concentrate that had never been evaluated as to its efficiency. Recent Gravity Recoverable Gold Testing by McGill University, and mathematical modelling of the Gravity Circuit by Knelson Gravity Solutions indicated the gravity circuit was not living up to its potential. Myra Falls Personnel changed the upgrade system-operating regime, and a complete gravity audit of the grinding circuit was carried out, with the results confirming the initial suspicions. Gravity recovery increased from 5% to 15%, with overall gold recovery improving by 5%.INTRODUCTIONNVI Mining operates a 4000 tpd mine and mill complex on Vancouver Island. The milling circuit consists of open circuit rod milling, closed circuit ball milling, gravity recovery, copper flotation, zinc flotation, and tails disposal. There are two milling circuits, “A” circuit, and “B” circuit."

Jan 1, 2006

By Cosmin Carpinisan, Erich J. Hofmann, Stephen J. Hall

"Since presenting a technical paper regarding their unique capabilities in Forged Steel Mill Gearing at the SAG-2006 Conference, Australian heavy engineering company Hofmann Engineering has pioneered a number of new manufacturing processes and design concepts for components of large comminution equipment. These include: 1. Novel design improvements for HPGR Rolls with forged steel tyres and a unique patented tungsten carbide insert designed to improve wear life, enhance autogenous layer build-up, and to reduce breakage & chipping under load. 2. Development of forged fabricated Mill Heads using rolled & welded high-tensile steel plate as alternatives to cast conical mill heads. 3. Insitu Girth Gear measurements for profile and wear via portable 6-axis CMM. 4. Gear and Pinion designs to AGMA-6114 for SAG mills of 38’-40’ diameter to 24MW and for Ball Mills of 26’ diameter to 18MW. The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering, combined with news of their new gear manufacturing and gearbox overhaul facility in Canada."

Jan 1, 2012

By C. S. Davis

In being asked to present this paper on the improvements in loading and hauling equipment and the effect on unit costs, Mr. Van De Water, your program chairman, stated that his reason for coming to a contractor was due to the wide experience of, and I quote: "a large contracting firm using a variety of equipment on varying types of earth moving jobs." We people in Utah Construction Company are flattered that Mr. Van De Water singled out our Company for this assignment. Utah Construction Company's participation in open pit mine stripping antedates the 1920's, when overburden was being removed from copper ore in Bingham Canyon, Utah. Our first stripping con¬tract for the Copper Company was finished in 1912. Since that early beginning, Utah has, as a contractor, been engaged to strip and mine iron ore properties, coal properties, copper properties, uranium properties, phosphate,-gypsum, limestone and dolomite properties. And, as you know, the Company has become a major producer of iron ore from Company-owned open pit mines. Utah Construction Company has been instrumental in the evolution of open pit mining tools. Some of the first tools were the old wood and coal fired stream shovels which had to be fired hours before a shift started to insure a full head of steam, providing power to excavate with the then large 1-1/2 cubic yard buckets. Today, Utah's strip mining is done, with 18 cubic yard and 10 cubic yard crawler shovels. Yesterday's horse and mule drawn, iron wheeled wagons, with 1 and 2 cubic yard capacity, which were hand dumped by removing the false bottom, one 2 x 4 at a time, have been replaced by today's- 50-ton capacity, hydraulic, rear dump trucks and giant 40-ton coal haulers. Utah Construction Company used the early fresnes and wheeled scrapers which were horse and mule drawn. Often, an operator holding too tightly to a handle was thrown into his horses when a hard spot turned the scraper, a contrast with today's 20 and 25 cubic yard, self-powered diesel and diesel electric Gargantuan rigs; with power controls that relieve the operator of practically all physical work. This Company has pioneered many of today's advances in equipment with shop made prototypes, features of which were adopted and elaborated upon by equipment manufacturers.

Jan 1, 1959

By Tom Meikle

Long tendon support systems provide several challenges when used in-cycle as part of the secondary or primary support cycle. A two-component pumpable resin, Carbothix, has been in development for use with self-drilling rock bolts, but many of the attributes of this new resin system make it ideal for grouting long tendon support systems. While neat Portland cement grouts or polyester resin capsules have been used with long tendon support systems for many years, two-component pumpable resin systems overcome many of the shortcomings in these systems. The two-component systems dramatically improve the set-time to enable mining face advance with fewer delays, enable longer pumping distances, improve quality control, and enhance load transfer mechanisms. This paper describes the key benefits associated with a new pumpable resin and details the Australian Department of Mines and Petroleum department atmospheric testing results and cable load testing completed by Minova personnel to date. It also details the results of the Australian mine site trials and the introduction of these systems into production use.

Jan 1, 2012

By George Mandarakas, Johan van Zyl, Karl-Heinz Becker

The world’s climate today has changed compared to 10 or 20 years ago. Many countries face water shortages; water sourcing for mining activities has become harder to secure. ESG’s focus on the industry has made us more aware of the need to preserve and responsibly use the water needed for wet processing in our milling and sorting activities. In a recent greenfield project in South Australia, 10 Gigalitres per annum would be required to process 5Mtpa of magnetite [1]. Published information indicates that the mining industry consumes approximately 12 EJ per year—or 3.5% of total global final energy consumption globally [2] or 3.33 trillion kilowatt hrs. This energy consumption is significant, considering the critical role mining plays in extracting and processing essential minerals for economic development and human progress. The perception of the mining industry is that not only does it consume significant power, but it also consumes a lot of the freshwater in the world. In fact, it consumes approximately 5% [3] of the total freshwater demand. According to the Intergovernmental Panel on Climate Change (IPCC), by 2050, 60% of the world’s population will be living in countries that are classed as water-stressed [3]. As more and more emphasis is placed on renewable energy sources, the amount of water used in mineral processing will increase because more and more raw materials require a water-intensive process. This increases the pressure on the mining industry to try and find water-saving initiatives. As part of this review, recent advancements in magnets have enabled magnetite processing facilities to achieve between 30 to 40% dry gangue material rejection before the wet beneficiation process (grinding and sorting). This reduction in energy consumption allows the reduction of energy consumption. Secondly, there is less material ground in the mills, which requires less water for mineral downstream processing.

Feb 1, 2025

By THOMAS J. CLIFFORD

IN 1926, finer grinding began to be a feature of the milling practice of the Southeast Missouri lead district. Nothing since the adoption of flotation has caused greater changes and greater improvement in results. The trend toward finer grinding, with the consequent discarding of tailing at finer sizes, and consequent lower assays in lead, continued to progress until 1931, when the abnormally low price of lead brought a halt: that is, the better metallurgical results obtained would not offset the increased costs due to higher power and necessary maintenance. Since 1931 a slight tendency toward the discard of coarser tailing has taken place. , In 1926, larger rod mills i.12 ft. 1 in. by 6 ft. 6 in.) than any previously used in the district were installed in cue plant, and a new primary crushing plant, of greater capacity was built. This combination demonstrated immediately the better metallurgical results obtainable by finer grinding and all the mills now running have adopted the practice.

Jan 1, 1934

By Corby G. Anderson

Since 1985, the Sunshine Mining Company has used a patented nitric-sulfuric acid pressure leaching system for production of silver and copper from a refractory sulfide ore body. To better understand this novel process, a program of lab scale testing was undertaken to quantify the effect of system variables on silver recovery. Some of the factors studied include temperature, agitation, acidity, vessel pressure, particle size, percent solids and oxidizer amount. In turn, this knowledge will be applied in actual plant practice to upgrade reaction time, increase concentrate throughput, raise silver recovery and lower reagent costs. A discussion of plant process changes resulting from lab scale testing is included.

Jan 1, 1991

By B Dunstan, F Wirfiyata

PT Newmont Nusa Tenggara (PTNNT) operates the Batu Hijau copper and gold mine and process plant on the island of Sumbawa, Nusa Tenggara (Barat)  NTB, Indonesia. The plant consists of a nominal capacity 120 000 t/d conventional semi-autogenous ball milling crushing (SABC) circuit followed by sulfide flotation to produce a bulk copper concentrate for sale. Process control is effected by a plant wide distributed control system that overlays an extensive integrated programable logic controller (PLC) framework. The system is enhanced by a supervisory expert control system.Since plant commissioning in September 1999, over US$4 million has been expended as part of a systematic continuous improvement approach to optimise plant control performance. Works completed to date include: redesign and upgrade of architecture of the control system to ensure long-term system reliability, security and upgradeability and to provide a suitable platform for advanced control; integration of supervisory and advanced control tools, techniques and instrumentation; and implementation of sound network communication and plant data reporting tools. This paper outlines the evolution of process control and associated systems and tools that contribute to successful operation and ongoing performance optimisation at Batu Hijau.

Jan 1, 2009

By P Cotton, N Cox

The Brisbane City Council has implemented a program of continual improvement at its Mount Coottha Quarry in the heart of Brisbane, Australia. The program has been underway for the past 6 years, and has resulted in very significant improvements in terms of both the cost effectiveness of its operation, and in terms of its environmental impact on nearby residents. The work has included a focus, amongst other things, on blasting efficiency and has challenged conventional thinking in terms of the size of blasts fired, the frequency of firing, the diameter of blastholes, and the use of bulk emulsion or slurry explosives.

Jan 1, 1996

By J. F. T. Agapito

Significant increases in extraction ratio on the order of six to eight percent, equivalent to as much as 142 t/m of panel advance, have occurred at the Big Island Mine during the last five years with the help of a practical rock mechanics program. This increase in resource recovery also has contributed to improvements in productivity. Both conventional and continuous machine mining have been used to mine two flat-laying trona beds at depths of 250 to 260 m in the Green River Formation in south-western Wyoming.

Jan 1, 1988

By James E. York

THE honor so fairly earned and so incompletely and tardily paid to Henry Cort, the inventor of the puddling-furnace and the, rolling-mill, has been fully set forth by Mr. Charles H. Morgan,1 and needs no further emphasis here. In view of the importance of the rolling-mill in the treatment of iron and steel, the paucity of information concerning it is surprising. With the exception of a hook, written about 35 years ago, by Peter Bitter von Tunner, an Honorary Member of this Institute, and of desultory articles on simple sections, which have appeared in technical journals, I know of no pub¬lication attempting to treat this subject, although volumes have been written on the scientific theory and technical manipulations involved in other branches of the iron- and steel-industry. This strange anomaly may be due to the fact that roll-turning cannot be called a scientific business. It does not ordinarily come within the range of an educated engineer; yet it cannot be performed by an ordinary mechanic. It demands some of the qualifications of an engineer, in designing, and those of a mechanic, in execution. The men who have followed this trade have controlled the training of their successors. In many cases the technical knowledge required bas been handed down from father to son, and there has been a motive of private interest to prevent its public dissemination. Moreover, the statement of the various principles involved in the process would require, besides manual experience, a degree of scientific knowledge which roll-turners do not usually possess; and, finally, any book on the subject, in order to possess real, practical value, would have to be so fully illustrated as to make it very costly to publish. Regarding my own experience, I may say that I served a six-

May 1, 1906

By Will B. Jamison

The most serious safety problems encountered in U. S. underground coal mines today are related to the roof bolting operation. Also, roof bolting is usually the operation which limits coal production of the section. The purpose of my paper is to review some of the research, developments, and new ideas related to roof bolting. Many of these ideas have originated at. coal mines or with manufacturers. Most of the research on fundamental improvements has been funded by, and is a part of, the excellent and broad plans of the Bureau of Mines.

Jan 1, 1977

By Adrian Dance

Newmont Ghana Gold Limited?s Ahafo operation have been working with Metso Process Technology & Innovation (PTI) since early 2009 to increase mill throughput from a combination of controlled blasting practices and optimised primary crusher and grinding circuit conditions. For such Mineto- Mill projects, PTI?s methodology is termed Process Integration & Optimisation (PIO). Ahafo operate a SAG mill, ball mill and pebble crusher (SABC) circuit that processes a range of primary ore of varying hardness from different pits which is blended with soft oxide material. The PTI study focussed on ball mill limited material from the Apensu open pit. Following a benchmarking study of all blasting, crushing and grinding practices in January 2009, PTI recommended changes in both blasting and crushing conditions in order to generate a finer feed size to the SAG mill. Additional operating changes in the grinding circuit were recommended. A series of trials were conducted in November 2009 where three blasts were fired using a different blast design (hole diameter and explosive type) in the same area of the Apensu pit as the benchmarked material in January 2009. Top and bottom benches (or flitches) from each blast were sent exclusively to the grinding circuit and the material was tracked using PTI?s SmartTag? system. The results from the six trials showed a significant increase in primary ore throughput at a reduced blend of oxide material. Ahafo have since standardised on these modified blasting conditions for all Apensu ore zones and have been able to sustain higher throughput compared to historical performance on similar material. This paper summarises the phases of the PIO project, the changes made in operating practices and the outcomes of the blasting trials that validated the predicted increase in mill throughput.

Jan 1, 2012

By I Elias, E Moya, S Chaffer

This paper is based on a case study from a mine site that operates two gyratory primary crushers. These crushers were encountering problems, which included inconsistent P80, reduced liner life tonnage and, on some occasions, catastrophic failure of the liners.As part of an evaluation process, both crushers were ‘mapped’ using a technology for condition monitoring and modelling of the crusher’s wear components. The technology provides comprehensive coverage of the crusher’s concaves and mantle at 100 mm intervals. It also automatically assesses wear rate between inspections and determines the highest wear areas. Outcomes include projected optimum reline dates at target replacement thicknesses, the identification of asymmetrical wear patterns, and the accurate measurement of open and closed (OSS/CSS) side settings.A comprehensive study was performed to optimise the performance of both these crushers at site. Over a period of seven liner service lives, the strategies to improved performance included liner analysis (concaves and mantle profile analysis), tonnes per day (t/d) and tonnes per hour (t/h) analysis, mantle reutilisation, detection and control of loose concaves, and detection and control of uneven wear and hot spots.These strategies resulted in the improved mechanical and operational performance of both crushers through concave and mantle redesign, OSS/CSS control, accurate wear forecasting plus other initiatives.As a result of these initiatives, the site now experiences benefits which include consistent product size, increased tonnes per hour (t/h) for both crushers and the liner life tonnage has doubled. Additionally, further benefits include less downtime for crusher liner maintenance and the reduced cost of inventories by mantle reutilisation.CITATION:Elias, I, Chaffer, S and Moya, E, 2015. Improvements in service life and cost reduction for gyratory primary crushers through mantle and concaves optimisation – a case study, in Proceedings Iron Ore 2015, pp 115–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015