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Ok Tedi Mining Limited has recently completed the first phase of a trial to compare the performance of D26B Krebs cyclones in different configurations to the new Warman 650 mm CAVEX cyclones. From 1992, rougher flotation feed size has increased from the target d80 grind size of 150 ¦m with increasing SAG mill throughput. At high SAG mill throughput, operators have difficulty maintaining the target cyclone feed pressure and must increase the cyclone feed density, thus resulting in a coarsening of the cyclone split. Warman International have developed the CAVEX high capacity cyclone. The new CAVEX cyclones, when compared to the Krebs units appear to:produce a measurable increase in volumetric flow for the same pressure drop; maintain or decrease the proportion of coarse particles reporting to overflow; and lower the overflow density. In all plant trials to-date, the CAVEX cyclones appear to be superior to the standard Ok Tedi Krebs cyclones. Further testwork is planned to evaluate modified Krebs cyclones (with recent design improvements) against the CAVEX cyclones.

Jan 1, 2000

By B. D. Hansen

Newmont has been on a focused path of improving operations for many years. After the merger of Newmont and Santa Fe Pacific Gold, Newmont created significant synergies of over $50million per year in Nevada, primarily through optimal ore movements and consolidation of various functions. During the current period of low gold and copper prices, Newmont has refocused its efforts on efficient operations worldwide. This paper will describe the methods and programs that continue to be implemented at Newmont's many mine facilities in Nevada. Newmont has used a combination of computer technology, optimal use of infrastructures, procurement strategies, functional consolidation, enhanced mine planning and a variety of available metallurgical processing options to decrease the cost of operations and increase profitability.

Jan 1, 1999

By B. D. Hansen

Newmont has been on a focused path of improving operations for many years. After the merger of Newmont and Santa Fe Pacific Gold, Newmont created significant synergies of over $50 million per year in Nevada, primarily through optimal ore movements and consolidation of various functions. During the current period of low gold and copper prices, Newmont has refocused its efforts on efficient operations worldwide. This paper will describe the methods and programs that continue to be implemented at Newmont's many mine facilities in Nevada. Newmont has used a combination of computer technology, optimal use of infrastructures, procurement strategies, functional consolidation, enhanced mine planning and a variety of available metallurgical processing options to decrease the cost of operations and increase profitability.

Jan 1, 1999

By AIME AIME

COMMITTEE No. 2 of the Iron and Steel Institute b f Great. Britain has presented its first report, of 27 printed pages, on blast-furnace plant and practice. This report outlines the various features of modern blast-furnace practice with brief comments thereon, and with references to some of the more recent methods devised for applying the principles and attaining the purposes aimed at' under these headings.. In general, the trend in the United States is in the direction of larger and larger furnaces with ever increasing capacity from which, with improved details in methods and equipment, and attention to details of management, considerable progress in. economy of production has been attained, in fuel consumption and in other items of production cost.

Jan 1, 1929

By W. K. Tolley

The U.S. Bureau of Mines (USBM) is currently investigating the electrochemistry of mineral flotation. A significant need in this area is greater reliability of sensors. The USBM is testing electrolytic methods to clean and condition redox-sensing electrodes to improve the reliability and extend the service life of these instruments in the harsh physical and chemical environment of mineral processing slurries. A novel method for removing scale from fouled electrodes has been developed that includes anodic polarization to 1.2 V versus the Ag/AgCl reference potential, followed by brief potentiodynamic conditioning. Laboratory results show that this technique removes calcarious deposits from gold sensing electrodes and returns the electrode to useful service within approximately 10 min. Mechanical abrasion to remove the scale is thereby avoided.

Jan 1, 1994

By Paul Richardson

This paper discusses the drilling techniques and equipment used by Loffland Brothers Company to drill the AEC's UC-3 large diameter shaft in Nevada. Included are pictures and illustrations of the drilling-mud circulating system, the surface and downhole drill-string and the special heavy-duty mast and hoisting equipment required to do the job. The purpose and method of lining the large diameter holes along with the technique and materials used to backfill the lining to hole annulus are discussed briefly. Areas requiring improvement in both equipment design and technology for large diameter shaft drilling are discussed briefly. Shafts as large as 140 inches in diameter to depths of 5,000 feet can be drilled with existing equipment and technology.

Jan 1, 1969

By Ian G. H. du Preez

It is illustrated how differences in the basic chemistry of individual metal ions can be exploited to develop new or improved separating agents. Factors like coordination number preferred by the specific metal ion, the degree of coordinate saturation reached by the metal ion and its relation to the phase transferability of the complex species, kinetic factors as opposed to thermodynamic factors controlling the success of the separation, the nature and type of the donor atom employed in a separating agent in relation to the preferences of the metal ion, the significance of stereochemical factors and the hydrophobicity of the media are some of the important factors which are discussed and applied for the development of pa1ladiwn(TI) and nickel(TI) specific separating agents, respectively.

Jan 1, 1999

By Esther Carrera Martinez

Caraiba Metals is the sole brazilian copper custom smelter. The sulfur present in the various concentrates processed is recovered as sulfuric acid and oleum ,which are sold in the local market For quality assurance purposes, a study was carried out in order to determine how to control the arsenic content in the acid, allowing the continuous processing of concentrates with high levels impurity, The study was based on the process parameters of the washing towers and mist precipitators, Others process variables were investigated and their effects were used in support to confirm the results, After many analyses performed some interventions to improve the quality of the acid were implemented in the plant, which proved to be successful even by using a conventional purification system,

Jan 1, 1996

By P Rubie, J Russell

This paper looks at the past, present and not too distant future of grinding mill relining.Since the adoption of autogenous grinding (AG) mills and semi-autogenous grinding (SAG) mills as the primary ore reducing devices in the comminution circuit, plant shutdown frequency and duration has largely been driven by the liner maintenance requirements of these mills.The past 30 years have seen the introduction of many technologies to reduce relining times and frequencies. Advanced relining systems have been developed which include single and twin Mill Relining Machines, capable of placing large (up to 8000 kg) liners, high energy recoilless THUNDERBOLT Hammers, and high capacity Feed Chute Transporters. Despite these advances, today many of the hazards associated with mill relining remain and reline times still vary considerably between mine sites. A sophisticated discrete event simulation program, designed to analyse the mill relining process, has revealed the dominant influences on reline times of crew performance and of the need for safe access to larger segments of the mill.A new generation of advanced and semi-automated technologies is currently being tested that will address these remaining challenges. These technologies remove people from the hazardous environment inside the mill and will allow techniques used in modern advanced manufacturing to provide a near-future step change in mill relining safety and performance.CITATION:Rubie, P and Russell, J, 2018. 21st century relining – the path to greater mine site profitability, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 621–640 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Shawn McWilliams, Aini Sun, Mike Lichte, Greg Colzani

The Allegheny County Sanitary Authority (ALCOSAN) adopted its Clean Water Plan (CWP) in May 2020, as part of a federal consent decree to comply with the USEPA’s Combined Sewer Overflow (CSO) Control Policy. Planned improvements include constructing a new regional storage/conveyance tunnel system, promoting green infrastructure/ source control, and expanding the treatment plant. Preliminary planning for the tunnel system was completed in October 2020. The Ohio River Tunnel (ORT) project is the first of three tunnel projects that make up the regional tunnel system. The ORT project began final design in 2021. This paper discusses the advancements made to the ORT preliminary planning concepts considering property availability, alignment optimization, tunnel boring machine evaluation, contract packaging and delivery schedules.

Jun 13, 2023

By J. H. Crary

This report summarizes the results of a one-year agreement for research on the electromagnetic environment in coal mines, which was conceived as the beginning of a long term cooperative program between ITS and the Bureau of Mines. The concepts on which it was originally based are a result of the report on mine rescue and survival by the Committee on Mine Rescue and Survival Techniques of the National Academy of Engineering, dated March 1970. This report drew particular attention to the need for improved communications during and following mine disasters. In particular, the outstanding problems identified were the location of, and communication with, trapped miners. Some tentative solutions, generally involving long-wave electromagnetic signals, were offered. Consideration of the problems of disaster location and communication soon leads to consideration of the communications techniques (or lack of them) for use under normal mining conditions. In particular, if a disaster communication and/or location system is to be readily available and operable under disaster conditions, it should also be usable during mining operations. In this way operators can become familiar enough with the system to operate it during disaster conditions, as well as provide a mechanism for regular testing.

Jan 1, 1972

By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

By M. Hao, L. Wang, Y. Yin, B. Yang

This study established a coupled fluid-electromagnetic numerical model to systematically analyzse the effects of molten steel flow, inclusion transport, and temperature gradients on refractory erosion behaviour within an induction-heated tundish. The results demonstrate that increased induction heating power significantly exacerbates both flow-induced erosion and magneto-thermal corrosion of the refractory lining in the channel region. The erosion rate exhibits a linear increase with power, while the wear coefficient follows a power-law relationship. Concurrently, a higher power level intensifies the inclusion collision source term by a factor of ten, substantially promoting inclusion collision, growth, and removal (increasing the removal rate by 14.86%). However, this also leads to a 51.3% reduction in the outlet inclusion particle size. This research provides a quantitative basis for balancing metallurgical benefits (temperature control and improved steel cleanliness) with the longevity-oriented design of refractory linings.

May 8, 2026

By Zay Jeffries

HOSTILITIES in Europe, Asia, and northern Africa were responsible for dislocations in rare-metal supplies during 1940. Although the consumption of some of the rare metals is small the dislocations may be relatively large. In some cases these are advantageous to North America and in others they are disadvantageous. Specific instances will be cited later. Barium T HIN films of barium metal on special steel balls greatly improve the life and reduce the friction of rotating anodes in highly evacuated small X-ray tubes and make possible the operation of these anodes at relatively high temperatures. These remarkable results are described in an article by Atlee, Wilson, and Filmer in the Journal of Applied Physics for September, 1940. Oil could not be used because of the high temperatures on the one hand and its volatility on the other. Fig. 3 shows diagramatically the rotating anode and the method of coating the steel balls with barium. The letters K.I.C. refer to "Kemet Iron Clad." The K.I.C. wire was mounted so that the barium could be evaporated by direct passage of the electric current. At high temperatures the barium dif-

Jan 1, 1941

By L. A. Baker

The presence of goethite in a hematite ore has been shown to strongly affect the time of heating to the firing temperature. The investigation of spalling of single pellets and of packed beds has enabled free water and goethite spalling to be identified as separate phenomena. In addition, it has been shown that even for an 18 inch deep bed of green balls the free water and goethite drying periods can be considered separately. Based on this observation, a method of predicting production rate and hood temperature profile is presented. The method required knowledge of the ore goethite content, ore grind and the green pellet bulk density. Laboratory results were found to be in good agreement with actual plant practice and have led to improved process performance.

Jan 1, 1972

By R Norris, M Dunne

Mining and mineral processing is expected by society and obliged by law to operate in an environmentally friendly fashion, minimising the impact on and avoiding damage to the environment. Substantial efforts by the industry, as well as by process and equipment designers have resulted in many innovative developments, which show that operating in an environmentally responsible manner can be achieved in a cost-effective way. This paper showcases five emerging equipment best practices in industry including installation examples. Flip-flow screening machines are proven worldwide in the dry classification of coal and other minerals, reducing the size of beneficiation plants whilst reducing energy, water demand and media consumption. They also allow the screening of wet/sticky materials not able to be sized using conventional screens. The belt press filter is a small fraction of the operating and capital cost of alternative dry tailings technologies. This gives operators who must dry their tailings a competitive advantage and makes such ægreenÆ operations much more sustainable. The filtercake is disposed with other plant rejects, eliminating the need for tailings dams to be constructed and thus also often increasing mine reserves. Mining applications include coal tailings, sand tailings, sinter plant waste and power station fly ash. Screen-scroll and vibrating centrifuges are widely used in the coal, potash and salt industries to dewater the product to low surface moistures. Inclined plate Lamella separators are used for toxic water clarification and/or sludge thickening in many downstream metal industries with the underflow often dewatered in a belt filter press. Such low cost, high capacity thickeners could also be used instead of conventional thickeners at smaller mines. The simple and reliable continuous washing upward flow (CWUF) sand filters have been used for treatment of waste water from coal preparation plants and steel works as well as in the worldwide production of potable water. The filtered waste water from mining processes can then either be reused or discharged from site. Other installations include cleaning mine water to prevent the blocking of dust suppression spray nozzles.

Jan 1, 2006

I once read an æarticleÆ in FHM Magazine entitled æThe Coolest Jobs There Ever WasÆ. It was about a group of guys who were pursuing careers that any person on the planet would just kill for. I distinctly remember drooling over the pages, thinking how much I would love to be Michael SchumacherÆs Chief Engineer at Ferrari, or the Principal Designer and Tester for one of the big Dutch rollercoaster companies. From that moment on, I decided that I wanted a career that was cool enough to make it into the pages of that article. Throughout my time at university, I always had that article in the back of my mind. As a result I constantly wondered about what sort of job I could end up with once I left university. More importantly, I wondered if FHM would be banging down my door to put me in the magazine! After a long and stressful job hunting process (in between completing a thesis and studying for exams) I finally managed to land myself a job with Orica Mining Services. I can honestly say I didnÆt know what to expect when I first joined Orica. Most of my friends ended up working for big mining companies, while I was offered a position with one of the biggest suppliers to these mining companies. However, I had a feeling when I was discussing the role with my future supervisor during the interview process that the job was going to be awesome. I have now spent a year working for Orica and I absolutely love it! While I feel that my job is worthy of being in that FHM article, unfortunately, I donÆt think I am going to get my opportunity to be in the magazine. Apparently I donÆt look too good in a bikini! However, I would love to have the opportunity to discuss the journey that I have taken so far û from my time as an environmental science graduate, then moving on to mining engineering, to now, being part of the Orica Mining Services Graduate Program. My suggestion is to use this paper as a resource. I have learnt during my time at university, as well as my time in the workforce, that the best people you can learn from are your peers. Take what you feel is relevant from the paper; hopefully it will help guide you in shaping your own career.

Jan 1, 2005

By A. J. Lynch

Mineral processing models have been discussed for many years but it was not until digital computers became available about 1960 that serious attempts at circuit simulation could be carried out. Even then the work was primarily academic until PCs could be used by engineers in plants and design offices in the mid-1980s. Since then simulation has moved quickly and it is now at the point that most processes can be simulated reasonably accurately for purposes of design and optimization. There are still some significant deficiencies, notably in dry grinding and separation, and in the chemical interactions in flotation. Future work will involve: ?improvements of existing models ?dynamic simulation for automatic control and, in particular ,for training which is a weak link ?using advanced simulation models to predict liberation and separation from data acquired from SEM-based liberation analysers. Eventually mineral processes models will be part of total simulation systems which will incorporate mining and downstream processes including all environmental impacts.

Jan 1, 1999

By K. Adham

For use in many existing and emerging applications, the purification of natural graphite is required to achieve +99.9% carbon content with minimum metallic impurities. Currently, the hydrofluoric acid process is used, which carries certain environmental and workplace health and safety impacts. While thermal purification of graphite at temperatures over 2500 °C is a known alternative, such high-temperature furnaces are expensive to build and operate. Using chlorine at lower temperatures to purify graphite is also known and patented, but is currently limited to treating solid synthetic graphite shapes in small-scale batch furnaces. Chlorine treatment of natural flake graphite resources can be used commercially, if certain drawbacks are addressed through process improvements that can be helped with the use of fluidized bed reactor technology.

By J. R. Kastler

It becomes my pleasant duty to call the meeting to order. This is our fiftieth regular meeting. And the session we are opening today, I am sure: will be as interesting and informative as those in the past. These gatherings present a fruitful opportunity for an exchange of experiences and ideas that will aid all of us in our work in the various segments within the coal industry. Walter Johnson and his Program Committee have arranged a wonderful program for us; Walter, due to his standing in the industry and his large acquaintanceship with the leaders of the industry, has really gone to town in bringing outstanding speakers and personalities to deliberate with us in our proceedings. A lot of things have happened since we last met; in the operating end, and in safety we have made marvellous headway, but we have slipped badly in the marketing end. However, I am sure the messages and discussion you will hear will point out ways and means of overcoming at least some of our difficulties. Before we get on with the program, I want to thank our hard working Secretary, Fred Whiteside, who, by the way, is a charter member of the Institute and has attended every one of the fifty meetings we have held; and the various committees who have been meeting for the past several months and who have arranged this fine program you are to hear. I hope all of you enjoy the convention; the business as well as the social sessions.

Jan 1, 1954