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NIOSH research has focused on the monitoring and the control of methane levels in active mine workings. Response times for instrumentation using catalytic heat-of-combustion sensor technology were evaluated. NIOSH research has modelled the flow of methane gas onto long-wall faces and gobs, developed engineering controls to limit methane levels during mining, and designed coalbed and gob degasification systems. Available methane control systems have been challenged by recent developments in longwall and room-and-pillar mining systems. This includes increased face advance rates leading to increased productivities, increased longwall panel sizes, and the generally deeper workings of U.S. coal mines. The potentially violent nature of any underground explosion or ignition requires the measurement, control, and reduction of methane emissions into the mine environment for continued worker safety.

Jan 1, 2008

By B. Samanta

This paper investigates the performance of the neural network technique in a placer deposit situated at the Nome district in Alaska. Initially a single neural network model was constructed to estimate the gold grade. However, at a later stage, an ensemble model consisting of multiple networks was also constructed via the Adaboost algorithm. The reason behind the use of the ensemble model of the Adaboost algorithm was to examine if the ensemble model provided superior performance to the single neural network. As indicated by other studies, Adaboost did not have a better performance than a single neural network in this specific application. This may be due to the high noise inherent in the gold data used in this project. Consequently R2 values of gold prediction are also poor for both the single and multiple networks.

Jan 1, 2005

By H. A. Schnell

"The Phase I Mill at Cluff Lake in northern Saskatchewan was designed to accommodate a very specific high grade uranium ore. As this high grade ore was depleted, construction was undertaken on a new mill circuit (Phase 2) to process a more conventional lower grade ore deposit.The Phase 2 Mill expanded the ore throughput to 800 tonnes per day. The new process employs crushing, grinding, leaching, counter—current decantation, solvent extraction and magnesia yellowcake precipitation and drying to produce a yellowcake concentrate.This paper discusses the process decisions required for this expansion and outlines the new mill circuit. Included is a review of the start up in August, 1984.1.,INTRODUCTION The Cluff Lake Uranium deposit is located 720 kilometers north of Saskatoon in northern Saskatchewan. A high grade deposit was discovered in 1970 with the first production taking place in 1980 after lengthy hearings. The original mill (or Phase 1 Mill) was specifically designed to accommodate this very high grade ore for a very limited plant life.Pilot plant work was carried out in 1981 on the other lower grade ores found in the immediate Cluff Lake area. Feasibility and process selection studies were then undertaken as the Phase 1 mill was nearing its end of life. These studies were completed in March 1983 when approval was given to construct the new Phase 2 mill."

Jan 1, 1985

By M. A. Jensen, J. J. Bettencourt

SYNOPSIS An analysis was made of records of accidents involving Bantu mineworkers and which resulted in either minor injuries or hospitalizations to determine patterns in underground accidents from which to formulate priorities in accident prevention in gold mines. The results showed that: (i) specific labour categories, such as inexperienced men, are exposed to certain types of hazards the extent of which warrant the separate design of safety programmes to meet their specific needs; (ii) the systematic study of minor accidents provides a dependable source of. information of which safety departments could make greater use in their efforts to control and prevent mining accidents.

By N Weerasekara, M Powell, P Toor

The effect of liner wear on SAG mill performance has gained much attention in recent years. It is commonly observed that the three key performance criteria of SAG milling; throughput, power and product size all improve as the liner wears.The increase in throughput is generally ascribed to the increase in the grate apertures and the increase in mill volume due to the wear of these components. Whilst the decrease in product size is attributed to the reduction in lifter height and angle, resulting in more breakage by means of attrition and abrasion.Though it is widely acknowledged that the wearing of liner components such as Lifters, Plates and Grates have a significant impact on mill performance, their individual contribution to changes in mill performance has been unclear, and resultantly lead to questions like; what percentage of the throughput increase can be attributed to the increase in mill volume (plate wear)? and how much can be attributed to the increase in grate aperture (grate wear)?It has been found that through the use of grinding surveys, analysis of production data and JKSimMet it was possible to separate the effects of changing liner profile, increasing mill diameter and increasing grate aperture on the mill performance allowing for the quantification of each.The outlined methodology allows for both troubleshooting of problem liner components which reduce milling efficiency in their wear life as well as providing a basis for a more quantitative approach to liner design and reline scheduling.CITATION:Toor, P, Powell, M, Hilden, M and Weerasekara, N, 2015. Understanding the effects of liner wear on semi-autogenous grinding mill performance, in Proceedings MetPlant 2015, pp 150–161 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Jacques B. Wertz

Both the San Andreas fault complex and the Murray fracture zone are apparently found to be contemporaneous with the Laramide mineralization period. Their compounding effects certainly have disturbed the Texas lineament belt and its components with serious lateral offsets and most probably have been instrumental in allowing intrusives to be emplaced as well as mineralization to accompany these intrusions at some of the fracture intersections. While the main fracture centers can be almost accepted as being structurally linked together, the Texas lineament trend definitely predominates, exerting a prevailing direction to graben (Silver Bell) and to elongated depressions (Bisbee). That this lineament belt also influenced the concomitant mineralization seems a logical inference. The orebodies are generally found at intersections near the most centrally-located intrusive with a distance varying from contiguity to one or two miles. The Southeast Arizona copper province owes its existence primarily to a particularly favorable structural setting of broad semi-continental scope. Thus, various regional structural elements are to be considered as possibly direct or remote cause for the widespread mineralization, although the one or the ones really responsible may never be singled out. There arc three basic regional elements: (1) The north-northwest-trending anticlinorium that diagonally crosses Arizona is quite obvious because many mountain ranges follow this direction. This anti- clinorium, which merges northward into the Wasatch-Jerome Belt, marks a broad zone of weakness where tension seems to prevail. Mineralized trends such as Jerome-San Manuel-Bisbee may give some weight to the economic value of this structural element. (2) Northeast-trending fractures, parallel to the Colorado Mineral Belt (Landwehr, 1967), appear troincident with mineralization as evidenced by the Questa-Grants-Morenci and the Lordsburg- Tyrone-Santa Rita alignments. This structural direction is accepted as one of the most economically significant in the Southwestern United States. (3) The Texas Lineament.

Jan 1, 1970

By Andre L. De Vegt, Cees J. N. Buisman

"For the past eight years Paques has been engaged in the development and installation of treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. Metal and sulfate can be removed from mine waters using two biological steps:1. Sulfate reducing bacteria convert sulfate to hydrogen sulfide (H2S). The H2S reacts with the dissolved metals to form insoluble metal sulfide precipitates.2. Sulfide oxidizing bacteria convert excess H2S to elemental sulfur.Paques has designed and installed a groundwater treatment system for the Budelco zinc refinery in the Netherlands to remove metals and sulfate as described above. The system has been operating since May 1992 treating a flow of 5000 m3/d. A test program, utilizing a large scale pilot plant, will commence in November 1995 at a copper mine in the U.S.A. to remediate groundwater contaminated with sulfate and heavy metals. Biological reactor performance and selective metal recovery will be studied. Sulfur dioxide (S02) can be removed from fluegas using a combination of scrubber technology and the two biological steps. The end product is elemental sulfur. A commercial size biological desulfurization plant has been in operation since July 1994 treating 50,000 Nm3/h of fluegas. Sulfide can be removed from mining waters or anaerobic wetlands using a THIOPAQ® Sulfide Oxidizing reactor.lntroductionSulfur can be present in various water and gaseous streams in a mining operation. In many cases the sulfur compounds have to be removed because of toxicity, corrosive properties and contribution to acid rain. Mine waters can contain dissolved heavy metals. An efficient way to remove dissolved metals removal is the precipitation as metal sulfides. Paques has developed and installed treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. These treatment systems biologically convert sulfate to hydrogen sulfide (H2S) which can be used in heavy metal precipitation. Excess H2S is biologically converted to elemental sulfur. This paper provides an overview of these newly developed biotechnological treatment systems."

Jan 1, 1997

By Axel Preusse

Mining subsidence plays an increasing important role in the Chinese hard coal mining. Reasons for this are a substantial rise of production during the last decade, a dense settlement in many mining regions, the increasing emergence of private residential property as well as a grown environmental awareness. German companies and research institutions hold an over more than 150 years existing know-how in all subjects of mining subsidence engineering. Due to partially comparable preconditions regarding mining depth, mining methods and geological conditions, a close co-operation between German and Chinese mining subsidence engineering experts has been in existence for some years. This German-chinese co-operation is introduced in this paper.

Jan 1, 2007

The Pogo Mine, near Delta Junction, Alaska is a new 2500 STPD gold operation. The control system of the mine and milling operations are a hybrid of DCS (Distributed Control System) control and PLC (Programming Logic Controller) control. A DeltaV DCS system serves as the main control and operation platform while the PLCs operate a multitude of vendor specific packages. The communication backbone of the DCS system is a hybrid of star and ring fiber optic topology, which provides reliability and flexibility. The communication between the DCS and PLCs is typically facilitated by serial communication. This communication insures the integrity of the whole control system.

Jan 1, 2008

By James M. Link

Slurry transport of industrial minerals has proven to be practical, economical, and efficient. Industrial minerals currently being pumped for long distances include cement, clay, phosphate, sand, and various waste product from industrial mineral processing operations. This paper will touch upon the basic theory of hydraulic transport of solids and then consider the economic and engineering considerations upon which construction and operation of such a line would be based. Where possible, actual cost data will be presented.

Jan 1, 1974

By D P. Yang, Yang R. G

The laws of throwing and heaping of engineering blast are important for making use of throwing and heaping of thrown body to form certain shape, such as building dams by directional blast. The article is to apply Ballistic theory of single thrown body to take the throwing course of thrown body as the movement of particle system, and then delimit the total of thrown body into units of thrown bodies, and regard the heaping shape of single thrown body as a perfect triangle, and found a quantitative relation between macro-geometry parameters of perfect triangle and designed parameters of explosives. The theory has been adopted in blast practice and gotten good effects.

Jan 1, 1999

By Charles Pretorius

Electronic Delay Detonators (EDDs) with remote wireless programming and initiation capabilities have been successfully used for almost two years now. This system has been used in blasts mainly in South Africa, but also in South America and other countries in Africa. Initially the industry was slow to accept the idea of remote programming and blasting. The advantages were not fully understood and there were some safety concerns. With close to 200 successful blasts as a reference, a much better understanding exists. The advantage of such a system becomes even more significant when the programming of the detonators is digitally integrated with the blast design software as used by the Blast Engineer. It is now possible to import a survey file into the blast design software, to do the blast design using actual hole positions and to then export the designed firing times directly to the detonators down the hole via remote wireless communication. Mines that have been exposed to this technology favour it to the extent that wireless centralised programming is becoming the norm against which other electronic delay detonator technologies are measured.

Jan 1, 2005

By R. Benito

This paper describes the development of a life of mine schedule (LOM) for one of the world?s largest known sedimentary Copper-Cobalt districts located in the Katanga Province, Democratic Republic of Congo (DRC). A particular feature of the Tenke Fungurume LOM schedule is the considerable number of pits/phases for scheduling, each competing to provide the best ore available to a capacity constrained process facility. This paper discusses the main scheduling objectives and constraints, data pre-processing as a scheduling aid, the mine scheduling approach, and results and conclusions.

Jan 1, 2011

Rutile – Zircon Mining on East Coast Surfing Beaches – Rutile-Zirconium Producing Companies in Australia

Jan 10, 1964

By J Young, S Yu, P Moyo, M Powell, A Musunuri, B Bonfils, S Kanchibotla, P Yaroshak, V Jokovic

The appropriate design of liners continues to be an issue on many mills worldwide. Loss of milling capacity especially at liner change, uneven wear lives along the mill, substantial scrap on worn liners, excess mill down-time, undesirably short and unreliable wear lives are all common issues. This paper presents a designed approach to liner optimisation that follows a logical path of initial design and step-wise improvements based on liner wear monitoring. The target is to have a good liner design from start-up, then tune the profiles, heights and thicknesses based on wear monitoring. This is conducted as a team of liner specialist, site personnel and liner supplier. The application to the Pustynnoye SAG mill of JSC Altynalmas in Kazakhstan is presented. The increase in liner life by around 50% along with increased mill throughput of over 20% illustrate the huge benefit of the cooperative triumvirate approach through the gains that can be made in productivity and reduced liner costs.CITATION:Powell, M, Kanchibotla, S, Jokovic, V, Hilden, M, Bonfils, B, Musunuri, A, Moyo, P, Yu, S, Young, J, Yaroshak, P, Yalcin, E and Gorain, B, 2018. Advanced mine to mill application at the Barrick Cortez mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 177–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By M. Tanaka, K. Aoki, T. Mori, H. Morioka, K. Iwano, T. Kanagawa

To estimate the detailed characteristics of the rock around the cavern during excavation, new monitoring technique for dynamic properties of the rock has been applied. In this paper, micro-seismic monitoring and AE monitoring technique are applied to the excavation of large underground rock cavern and the result was discussed to clarify the acutal behavior of EDZ around the cavern. Zur Einschätzung der Gesteinseigenschaften um die Ausschachtung herum haben die Autoren eine Technik eingesetzt, mit der die physikalischen und dynamischen Änderungen im Gestein um den Schacht während der Ausschachtung beobachtet werden. In der vorliegenden Studie wurde zur mikroseismischen Überwachung ein AE Überwachungsverfahren eingesetzt und die Autoren berichten über die Veränderungen in den Gesteinseigenschaften um die Ausschachtung herum. Dans le but d'évaluer en détail les propriétés des roches qui forment les parois des cavernes creusées, les auteurs ont utilisé une technique de mesure permettant d’observer les modifications physico-dynamiques des roches aux alentours de la caverne pendant son excavation. Dans le cadre de cet article, une technique de surveillance de l’agitation et du bruit microséismiques a été mise en œuvre et les auteurs font état de la modification des propriétés de la roche environnante.

Jan 1, 2003

By A. More, J. M. Míguez, J. Bullón

In 2000 Ferroatlantica started a project with the aim to develop a new casting machine for silicon and other ferroalloys. Until now, it has been cast more than 25.000 tons of silicon for the chemical and metallurgical market. This system has improved the process yield, productivity and product quality which place?s Ferroatlantica at the top of technology development in this field. After the first presentation of the Ferroatlantica?s casting machine at Infacon X, we would like to show the improvements in the control which have permitted us to increase the lifetime of the copper and to obtain, at the end of the machine, the right product size for the customer avoiding the current necessity of crushing and sizing the lumpy metal. Furthermore, we have improved the system in relation to the obtaining of smaller granulometries at the end of casting machine. Not only is this kind of machine cost competitive for special silicon applications but also for other normal ferroalloys with different specifications of size and thickness.

Jan 1, 2007

By B. K. Mishra

In order to maintain higher grinding efficiency in tumbling mills the mill interior and dynamics must be known. For this purpose, several different types of non-intrusive methods have been proposed and are being tried in the industry. We have made an effort to develop a diagnostic tool based on vibration signal. Here we discus results of our experiments pertaining to ball as well as SAG mill. In each case, a triaxial accelerometer was used to capture mechanical vibration generated due to the tumbling action of the charge. The vibration signal was transmitted to a remotely placed computer and the signals were analyzed by standard signal processing technique. In case of a ball mill (5m diameter), qualitative mill information could be obtained by correlating the vibration signal to feed rate and mill filling. An effort was also made to identify different motion characteristic of the charge by analyzing its vibration signal. In case of the SAG mill (10m diameter), liner wear was estimated by comparing the vibration signal emitting out of a freshly lined mill with that of a worn out mill.

Jan 1, 2011

By V Cullinan, D Buchanan

The Brunswick plant is located in Costerfield, approximately 40km east of Bendigo in central Victoria. Crushing, grinding, gravity gold concentration and flotation methods are used to produce a saleable gold concentrate and an antimony-gold flotation concentrate. This paper discusses the improvements made within the processing plant which have resulted in a 99% increase in throughput over nameplate capacity of 6 250 average tonnes per month to 12 445 average tonnes per month and increases of 12% gold (from 2007 average of 78% to 2014 average of 90%) and 16% antimony recovery (from 2007 average of 79% to 2015 average of 95%). This combined effort has resulted in an increase of equivalent gold ounces (AuEq oz) produced from 2010-2014 of 15 872 to 82 574 – a 66 702 increase.AuEq oz= Au oz +Sb t × Sb (US$/t)Au (US$/oz)CITATION:Buchanan, D and Cullinan, V, 2015. Improvements in bi-metal production at the Brunswick Plant, Costerfield, in Proceedings MetPlant 2015, pp 267–272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Earl Sweet

This overview of economic and financial market prospects examines the current and future state of the global and Canadian economies with a focus on commodities. Housing prices and global conflicts all have effects on the overall economy and metal prices and mining developments in particular. This presentation outlines where we are today and where the author and BMO see the economy moving over the next few years.

Jan 1, 2016