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By Andrew N. Peterson

US mine operators frequently fail to investigate more cost effective and productive bulk material handling systems because surface mines seem to lend themselves to truck ore haulage. In this country, as a result, use of conveyors to move heavy loads from mine to process facilities has been minimized, if not actually neglected. In contrast, there are more than 50 conveyorized surface mines in successful operation around the world. These mine operators have learned that properly applied conveyorized systems can offer major savings in capital and operating costs, which contribute to improved profits when combined with other proven mining technologies. Growing acceptance and application of conveyorized bulk material handling in surface mines also points up how unique each mine is and how careful planning contributes to maximum mine effectiveness. Because of these differences, mining executives and technical and operating staffs need to develop an understanding of three factors in applying conveyorized bulk material handling in surface mines: • Why each mine will benefit from the type of automation permitted by conveyorized operation, •What kind of equipment is available, and • What applications most effectively demonstrate the first two factors in action - hauling either ore or waste. The conveyorized systems considered in this presentation have production rates from 0.5-2.7 kt/h (500-3,000 stph). Worldwide, these systems have been operating since the early 1960s. Advantages of Conveyors Why do you want conveyorized bulk material handling? First, it almost always provides lower operating and maintenance costs. Second, it frequently requires lower initial capital costs and almost always requires lower capital costs over the life of the surface mine. Third, it provides comparable operating availability, and finally, it frequently gives comparable operating flexibility - depending on the mine plan. Cost avoidance can be accomplished with modern production methods. These, in turn, permit increased productivity and reduced operating costs such as those for energy, maintenance, and manpower. It has been demonstrated in European surface mines and elsewhere, that conveyor systems frequently require lower initial costs than does truck haulage. Almost always such operations require lower capital costs over the mine life. Those costs include the continual addition of haulage trucks to both accommodate the increasingly difficult haulage routes and fulfill replacement requirements when trucks wear out. Conveyor systems handling ore in numerous large crushing and port facilities, which have operated since the early 1950s, have clearly demonstrated a useful conveyor life of more than 25 years. In contrast, off-highway trucks have life spans of six to eight years. The following examples illustrate comparative capital costs to purchase conveyor systems and comparable truck haulage units. Example 1 The ore haulage route from point A to point B is level and 610m (2,000 ft) long. The material weighs 1.8 t/m3 (110 lbs per cu ft) and must be transported at a rate of 1.8 kt/h (2,000 stph). The installed capital costs to provide a properly designed conveyor that will transport the described material from point A to B is about $450,000. The capital cost to purchase three 77-t (85-st) off-highway trucks and one spare truck - which would provide equivalent capacity - would be about $1.2 million. The truck cost estimate is based on a 6 min. or 771 kt/h (850 stph) truck cycle time. Truck efficiency is estimated at 0.8. Each 77-t (85-st) truck would have an actual haulage rate of 617 kt/h (680 stph). Therefore, three trucks would be necessary to transport the designated tonnage of 1.8 kt/h (2,000 stph). A movable crushing plant would be located at point A for the conveyors and a permanent crushing plant at point B for the truck haulage system. Capital costs for these primary crushing plants were not included in the calculations for either system because the capital costs are frequently comparable. Example 2 The transport route from point A to point B is 610 m (2,000 ft) horizontally and 122 m (400 ft) vertically - on a 20% grade (Fig. 1). The material weighs 1.8 t/m3 (110 lbs per cu ft) and must be moved at a rate of 1.8 kt/h (2,000 stph).

Jan 6, 1983

By C. Ford, R. E. Salas Rojas, J. P. Contreras Rodriquez, S. A. Pierce

Heightened environmental consciousness has resulted in the development of various international accords dealing with natural resource management. This international awareness is now being translated into regional and local initiatives that proactively implement collaborative environmental management programs. One such program was recently initiated in northern Chile in recognition of the interconnection of Andean salars. Cooperative efforts between industry, governmental agencies and academic professionals have resulted in the implementation of simultaneous environmental monitoring of flora and fauna in the salars of northern Chile. This coordinated effort is leading to an improved understanding of the migratory patterns of South American fauna, as well as improved access to an expanded database for the multiple user groups associated with the Andean salars. The El Abra Mine is actively participating in these coordinated monitoring efforts.

Jan 1, 1999

By G. M. Thain

Ancient Mining - The following three contributions were received for publication in addition to the preceding papers. 1. Ancient gold-mining sites in the Transvaal G. M. THAIN* Pre-European gold mining and working in South Africa is a tantalizing field for conjecture. Well over thousand sites have been identified in Rhodesia, but here we have had to reach double figures, judging by published accounts. Geologically, the Transvaal is less amenable primitive exploitation, but it difficult to reject the idea that the knowledge gained to the north did not have its influence south of the Limpopo.

Jan 1, 1974

By Joseph Jensen

THE history of the normal oil field is supposed to show an oil graph stalting high in flush production, descending more or less steeply into the curve of settled production and dropping gradually to the vanishing point of economical operation. Together with this at somewhere in the early history of the field, there appears from a vanishing point a graph showing the production of water. During the period of settled production this graph rises higher and, toward the close, unless extensive work is done in the line of correction, rises far above the oil graph to where the cost of operation terminates profitable pumping. Fields that start out with a high relative content of water are generally very short lived. Fields that never develop a water problem are exceedingly rare.

Jan 1, 1930

By V. H. Gottschalk, John Grodd, R. S. Dean

"Elemantary ConsiderationsAlthough magnetiem was first discovered in and derives its name from an oxide of iron found in magnesia and called lodestone its pracical uses date from the discoveries of Faraday concerning its relation to the electric current. We may therefore start our discussion of magnetic properties with Faraday's law for relation between induced electromotive force and the change in a magnetic where e is the electromotive force induced in an electric circuit by a unit rate of change of magnetic flux N, H is the intensity of the magnetic field, S is the area enclosed by the circuit, and i an angle between H and the normal to dS. In the simplest case we could use this law to measure the strength of a magnetic field by passing it at a measured rate through a coil of copper wire and determining the,electromotive force. As a matter of practical convenience, it will be simpler to nee the total quantity of electricity produced by a change of magnetic field. For this purpose we may let i denote the strength of the electric current induced by the change of magnetic field in time in a circuit of area a and resistance R. Then the total electric quantity. Q is given. by"

Mar 1, 1934

By O. C. Baptist

This report presents results of an investigation undertaken by the Bureau of Mines to determine the clay content of typical petroleum reservoir sands in Wyoming and the effect of clay content on the permeability behavior of the sands. These results should have significance in determining the feasibility of injecting water into the sands for secondary recovery and in estimating the probable damage incurred by these sands if invaded with filtrates from water-base drilling muds. The results of air-, brine-, and water-permeability determinations are given for reservoir sands in three Wyoming fields. The amounts of materials of "fine silt and clay size" (Wentworth scale) in the sands and the types of clay minerals present, as identified by X-ray diffraction methods, are also presented and discussed.

Jan 1, 1955

By Jie Deng, Wenliang Xiong, Binyan Chen

"With falling rare earth metal prices, low cost beneficiation of rare earth minerals is essential. The “Flotation-Agglomeration-Magnetic” (FAM) separation process is a newly developed technology by IMUMR to economically recover rare earth elements from different types of deposits. The theory of FAM process is to selectively agglomerate rare earth particles and separate from gangue minerals by bubble flotation process. The flotation product is further upgraded by magnetic separation. The FAM process has been successfully applied in industrial production on the Dalucao rare earth ore, Sichuan, China. The average REO grade of rare earth concentrate is 65% in the latest 12 month production run, with an average recovery of 55%.INTRODUCTIONRare earth elements (REEs) include fifteen lanthanide elements coupled with two chemically similar elements (yttrium and scandium). These elements are split into two sub-groups, La to Sm are classified as light rare earth elements (LREEs) and the remaining elements including yttrium are heavy rare earth elements (HREEs) (Kumari & Panda, 2015). The demand of rare earth elements surged in recent years due to their increasing usage in diverse industrial aspects including high strength magnets, phosphors, clean energy, polishing compounds and catalysts (Goley &Scott, 2014).More than 250 REE-bearing minerals have been discovered, but many minerals are with very low concentrations of REEs, varying from 10-300 ppm (Adam &Ping, 2013). The most common rare earth minerals mined are bastnaesite, monazite, xenotime and ion-adoption REE (Chelgani & Rudolph, 2015; Kanazawa & Kamitani, 2006). Before the 1960s, most rare earth resources were extracted from monazite in the beach placer, with the exploiting of Mountain Pass in the United States and Bayan Obo mine in China, bastnaesite became the chief mineral source of rare earth resources (Klinger, 2015). These minerals are commonly separated with gangue minerals by froth flotation, gravity concentration, magnetic separation, or any combination thereof based on their specific physical characteristics (Zhou & Wang, 2014; Adam & Richard, 2014; Yang & Satur, 2015; Xia & Brian, 2015a,b)."

Jan 1, 2016

By Hugo Medina Medina

El presente trabajo refiere el proceso de mineralización de fluorita en la mina Pasto Bueno, Ancash, el cual por sus características mineralógicas y estructurales es considerado como potencialidad geoeconómica en tungsteno. El estudio de la evolución geo-técnica del yacimiento comprende la estratigrafía, geología económica y los rasgos de la evolución geo-técnica del yacimiento Pasto Bueno a través de un esquema vinculado al desarrollo geosinclinal andino mesozoico y los conceptos de la Neo-técnica global. Una vez realizado estos estudios, se busca una mejor exploración y desarrollo minero del tungsteno-fluorita en el territorio nacional a fin de autoabastecerse de la fluorita en el campo de la siderúrgica.

Nov 20, 1978

By G. P. Wong

"In the Inco matte separation process, a slow-cooled converter matte is separated into three main discrete mineral phases: chalcocite (Cc), heazlewoodite (Hz) and a Cu-Ni-Fe alloy. After magnetic removal of the alloy, Cc and Hz are separated by flotation at pH>12 with diphenyl guanidine (DPG) as both collector and frother. High selectivity is achieved in rougher flotation. However, in later flotation stages such as in the middlings circuit, as oxidation takes place, Hz becomes highly floatable, resulting in a very poor separation between Cc and Hz.Starch and dextrin as Hz depressants were evaluated on the middlings circuit feed and showed no positive impact on Cc/Hz separation selectivity. Ethylene diamine tetra-acetic acid (EDTA) extraction showed the existence of abundant surface Cu and Ni ions. The use of triethylene triamine (TETA) or EDTA in flotation did not improve Cc/Hz separation selectivity. Microflotation tests were carried out on pure synthetic Cc and Hz minerals. It was found that Hz did not float in the presence of DPG. However, Hz conditioned with either copper sulfate solution or in contact with Cc floated readily in the presence of DPG. It is concluded that the major reason for Hz flotation in the middlings circuit is due to Cc oxidation releasing Cu ions that adsorb on the Hz surface making it reactive with DPG thus rendering the Hz floatable."

Jan 1, 2003

By Antonio Chávarry C.

El planeamiento minero desarrolla una función importante en la producción minera peruana. En esta perspectiva, el texto describe el programa de plan de minado actual en la Empresa minera de Hierro, Ica como parte del planeamiento a mediano y largo plazo de alcance de dicha compañía. Entre los objetivos del plan está la determinación del volumen de crudos por mineral y de otros materiales, la determinación de minas que deben ser operadas para cumplir los fines requeridos y la estimación de los diferentes insumos para el nivel de producción planeado, así como la disponibilidad de equipos para la operación de minado.

Oct 14, 1980

By Paul J. Axtell

The design-build delivery system is being used to erect the landmark Christopher Bond Bridge as part of the kcICON project. The cable-stayed bridge is currently under construction and will span the Missouri River on I-29/35 in Kansas City, Missouri. The design-build process for the foundation work on this project has been successfully implemented as a result of cooperative efforts between the foundation designers and the constructors to develop a constructible design.

Jan 1, 2009

By Alejandro Trujillo Cabanillas

El presente texto señala las características del yacimiento geológico Cerro Lindo determinándolo como parte del tipo sulfuros masivos volcanogénicos (VMS) y propone un modelo genético de su formación genética. El yacimiento minero Cerro Lindo se ubica en Ica, Perú y es depósito de sulfuros masivos volcanogénicos donde dichos sulfuros bandeados de baritina y Zn se depositaron por precipitación de los fluidos hidrotermales calientes en contacto con el agua de mar. A medida que la temperatura ascendía en las celdas hidrotermales, se desarrollan los sulfuros piritosos con los fluídos cupríferos, de forma que las fallas sin volcánicas sirvieron para que la ocurrencia de bajos estructurales donde se desarrollaron cuerpos de gran potencia, determinen los altos estructurales que preservaron sulfuros masivos de alta ley de zinc.

Sep 9, 2007

By F. Rudloff, C. Karageorgos, J. Moyo, I. Boadi, M. Struble, B. Lumsden

Over it’s more than 100-year history, the Kennecott operation has often been at the forefront of innovation; driven by the demands of the lower grade ore-body and the higher costs of operating in the US where wages are generally higher and regulation more restrictive. One way of reducing operating costs in c/lb is to increase the lbs produced at minimal cost. Despite the relatively coarse grind at Kennecott - about 30% >150μm, approximately 20% of the Cu lost to tail is liberated chalcopyrite in the <20μm fraction, and about 30%-40% in the <37μm fraction. In 2020 Kennecott undertook a detailed plant scale test of the magnetic aggregation technology to increase copper recovery by reducing fine copper losses. A paired statistical plant test of magnetic conditioning on one rougher line showed a 1.12% increase in Cu recovery to 97% statistical confidence. The next challenge, unforeseen at the start of the project, was the fabrication and transportation to site of the equipment for the three remaining rougher rows, during the severe supply-chain constraints of the Covid pandemic in 2021. This resulted in delays and unforeseen costs as world-wide transportation became chaotic, particularly transportation via west coast USA. Nevertheless, the project was completed and commissioned, with only minor delays and cost increases, due to a flexible approach to overcoming the hurdles encountered.

Feb 1, 2023

By C. A. Holley

The generation of coal fines is a growing problem which has serious environmental and resource recovery Impact. Several methods of agglomeration are studied including the production of briquettes for the consumer market. Simplified process flow diagrams, "order of magnitude" plant capital cost and operating costs are presented.

Jan 1, 1986

By G. Kumar

Water for domestic consumption is an essential right of society, which must be over secured. Water reclamation and reuse provides a unique and viable opportunity to augment traditional water supplies. As a multi-discipline and important element of water resource development and management, water reuse can help to close the loop between water supply and wastewater disposal. Effective water reuse requires integration of water and reclaimed water supply functions. During the coal mining activities, large quantities of water get contaminated and loses its potability characteristics. On an average, in coal mine operation, each coal mine discharges effluents at a rate of nearly 0.5 MGD and thereby wastage of nearly 50 MGD of water takes place per day from the famous Jharia Coal Field of the Dhanbad District. In this paper, attempt has been made to control the extremely high turbidity of mine waste water by using different coagulants and it is observed that ferrous sulphate is the most effective coagulants followed by alum, ferric sulphate and lime. Also combinations of coagulants are used for getting the optimal results. Further steps were also discussed to make this water potable and a scheme of low cost water supply system of mine waste water has been suggested under the Water Management Strategies. Keywords: potability, turbidity, coagulants, water management strategies

Sep 1, 2012

By Eleazar Salinas R., Miguel Perez L., J. Cesar Juarez T., Martin Reyes P., Eduardo Cerecedo S., Isauro Rivera L., Francisco Patino C., Juan Hernández A.

"A complete characterization of burrows from Mining district of Pachuca - Real del Monte, in Hidalgo state Mexico, was done. These kind of residues had not been formally characterized, founding an average chemical composition of 70.43 % wt. of Si02, 7.032 % wt. of Ah03, 2.69 % wt. of Fe20 3, 0.70 % wt. of Mn, 3.98 % wt. ofK20, 3.34 % wt. of CaO, 2.50 % wt. ofNa20, 1.01 % wt. of MgO, 0.26 % wt. of Ti02, 0.04 % wt. of Zn, 0.026 % wt. of Pb, 56 g/ton of Ag and 0.6 g/ton of Au; In the same way, the residues present as majority mineralogical phases the following: Quartz, Berlinite, Orthoclase, Feldspar, Anorthoclase and Calcite. By the other hand, joint with the big volume that present these residues and the chemical and mineralogical characteristics, these materials or sub - products can be used for production of ceramics, into mixes forming some materials for architecture (bricks, blocks, and tiles), refractory bricks, in the production of cement and to get some metallic values such as gold and silver involved in these residues.IntroductionActually the mining residues in Hidalgo State, Mexico are the result of more tan 500 years of mining, leading so a great volume of deposits, which we can classify in different types, among the most communes we have: Acid Mining Waters, Waters of solid transport and elements in the form of radicals, deposits of abandoned minerals without processing, and mining wastes of processed minerals known as burrows or dumps, being these the most abundant in the Hidalgo State [1-4].Form the metallurgical point of view, it is known that a characterization study if fundamental to find the viability of reuse of these kind of residues, leading so an additional use and the opportunity of get an alternative use into several industrial processes, due to its contents of oxides of silicon, iron, aluminum, calcium, sodium and potassium, principally, besides of its mineralogy and distribution of chemical elements into its primary and secondary phases [ 1-2, 5- 6]."

Jan 1, 2011

By Carson Rife, Michael L. Clark

INTRODUCTION Zortman Mining Inc. is a wholly owned subsidiary of Pegasus Gold Corporation of Spokane, Washington. Pegasus has been producing gold and silver from the Zortman and Landusky mines since 1979. The Zortman and Landusky mines are two distinct open pit mines located approximately 6 kilometers apart in the Little Rockies Mining District of north central Montana. The two mines use large-tonnage, low- grade heap leaching techniques to efficiently process the gold and silver ore. PROJECT DESCRIPTION The Little Rockies rise abruptly 914 metres from the surrounding plains to about 1829 metres above sea level. The topography is quite steep, making efficient leach pad construction a major challenge. The climate is semi-arid with moderate summers and occasionally severe winters. Freezing temperatures usually arrive in late October or early November, influencing the effectiveness of leaching operations. GEOLOGY AND MINERALOGY The geology of the Little Rocky Mountains consists of steeply dipping sedimentary ridges forming an elliptical dome surrounding a core of intruding syenite porphyry. Within the syenite porphyry are well fractured and mineralized shear zones where the existing reserves and open pits are located. The ore is presently divided into oxidized, mixed, and sulfide. Only the oxides and mixed zones that are of ore grade are placed on the leach pads. The syenite porphyry host rock enables effective leaching of gold and silver to depths of 61 metres, having a major impact on leach pad construction costs. MINING All mining since 1979 has been by contractor. This enabled initial mining to commence without capital investment in equipment. Through competitive negotiations, Pegasus has been able to keep contract mining costs at levels very close to what would be experienced if Pegasus had purchased equipment initially. Contracts are negotiated yearly and are based on a unit price and haul distance for ore and waste. Haul distances have ranged from as little as 457 metres to as much as 3,050 metres. At present, Pegasus is developing a 27,000,000-tonne leach pad at the Landusky project that is adjacent to the minine area. This design feature will reduce the mining cost by 20 percent over the life of the mine. In 1987, over 5,900,000 tonnes of ore and 3,200,000 tonnes of waste will be mined at the Landusky project. Through 1986, 13,763,000 tonnes of ore have been mined at a waste-to-ore strip ratio of 0.60:l at the Zortman project, and 13,005,000 tonnes of ore at a waste-to-ore strip ratio of 0.79:l have been mined at the Landusky project. Current mining reserves are 32,769,000 tonnes of ore at a waste- to-ore strip ratio of 0.59:l. Through efficiencies of large-scale heap leaching, Pegasus has been able to lower the mining cutoff from 0.34 grams per tonne gold to 0.27 grams per tonne gold. This has reduced the mining cost per tonne of ore h percent through a reduction in strip ratio of 14 percent. Beginning in 1984, all pits were designed based on computer-generated "floating cone" pits. The geologic models were developed by Pegasus staff with a series of economic models evaluated. The resulting computer-generated pits were used as a guideline in designing the mine plans, including haul roads for final calculation of tons and grade. Input to the floating cone models consisted of mining cost, processing cost, cutoff grade (0.34 grams gold per tonne), recovery (67 percent) and gold price. Due to the gold being deposited primarily on the fractures of the syenite host rock, no crushing of ore is needed prior to leaching. This characteristic of the ore is a key in being able to profitably mine and process gold ore at an average grade of 0.69 grams of gold per tonne. Strict blasting control is also a key in success of the leaching operation. A system of splitting ore and waste in blast patterns has been devised to reduce dilution. Also, drill hole spacings are varied from 3m x 3m in breccia ore to 4m x 4m in syenite ore to 5m x 5m in waste. Drill holes

Jan 1, 1987

By A. Supomo, H. Resendiz, C. Burbidge

"Freeport-McMoRan Inc. (FMI) commissioned the expansion of the Morenci Metcalf concentrator in 2014. The concentrator included many design and equipment innovations, including the first-of-its-kind Metso Hydraulic Roll Crusher (HRC), variable speed ball mills and variable speed crushers. In addition to the innovative design, FMI commissioned the Metso APC team to design a realistic process simulator and the plant APC. The process simulator was utilized to train operators before commissioning, which led to a smoother plant start up. The plant APC utilized the concept of dynamic constraint control, which controls the feed to the primary ball mills by “pulling” the tons from crushed rock storage bins, which then automatically are filled by the upstream HRC and secondary crushing circuits. The primary ball-mill control also adjusts the water addition to the cyclone clusters to avoid overload and achieve sufficient grind size. The constraints include in-circuit constraints for feeder capacity, screen-deck capacity, ball mill power, cyclone mass flow, pump capacity and pump motor capacity. The APC system was implemented shortly after the start of commissioning and immediately demonstrated increased throughput and an ability to highlight and quantify process constraints and bottlenecks. The following paper outlines the control strategy, discusses system implementation, results and challenges.INTRODUCTION The FMI Metcalf Concentrator is located in Morenci Arizona on the site of the old original Concentrator. The new Metcalf concentrator started operation in May of 2014. This plant was designed for an average of 63,500 tpd (70,000 stpd), increasing the total Morenci concentrator complex production to a nominal 113,400 tpd (125,000 stpd). The process flow diagram is shown below in Figure 1.The process consists of primary crushing feeding a coarse ore stockpile followed by secondary crushing operating in closed circuit with vibrating screen decks. The screen undersize feeds the first of its kind Metso hydraulic roll crusher (HRC) operating in a closed circuit with vibrating screens. The primary crusher is a Metso 60x110 gyratory crusher. Secondary crushers are Metso MP1250 Crushers with variable speed drives. Secondary crusher discharge is recycled to the dry screen feed bin and screened with oversize returning to secondary crushing and undersize feeding the Metso HRC3000. The product from the 3.0 meter X 2.0 meter roll crusher is wet screened with the undersize feeding the grinding circuit, which is comprised of two each 24-foot diameter by 40- foot-long variable speed ball mills running in parallel with each in closed circuit with a cyclone bank of 12 cyclones. The wet screen oversize is recycled to the HRC feed bin."

Jan 1, 2019

By N. C. Joughin

Progress during the last two years in the Chamber of Mines programme for the development of mechanized stoping methods is reviewed, and advances in the basic technology are outlined. Specifically. advances in the understanding of rock fracture around stope faces. in rockbreaking techniques, in rockhandling techniques, and in engineering are described. The state of development reached with mining systems based on cutting, impacting. and blasting is also described.

Jan 1, 1978

By Gang C, Changyi S, Liangde G

Geophysical and geochemical methods and techniques for gold exploration and their applications in China are summarised in the paper. Some case histories are also presented. The effect of prospecting for gold deposits using these methods is well illustrated through these examples.

Jan 1, 1997