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By V. Bruned, K. Mohamed, A. Michaut

Orano Mining Somaïr uranium treatment plant (Niger) uses a pugging-curing process to leach uranium. Sulfuric acid, nitrates and water are added to the finely grinded ore in a rotary drum to leach uranium bearing minerals and solubilize uranyl sulfate ions. Reagents, sulfuric acid and nitrates, are the main OpEx of this process step. The economical optimization of their addition requires a thorough knowledge of the ore behavior in solution with these reagents. Orano Mining technical direction and Somaïr laboratories developed a model to predict the curing process uranium recovery surface with a limited number of parameters. Experimental laboratory work to fit the model needs to be done for each type of ore which can require a lot of metallurgical tests and would be time consuming. In order to optimize the required number of tests, an innovative experience plan was designed in parallel to the development of this model reducing the required number of tests to only eight. Once the parameters of the models are correctly fit, the comparison between the estimated values and the actual values for the uranium recovery is excellent (less than 0.5% error in average). Associated with an updated cost model of the curing process, this new recovery model helps the plant operator find the best set of reagents to maximize curing process profitability in the Somaïr plant day after day.

Jan 1, 2020

By Gerhard Kircbner, Boen Tan

"IntroductionThe Key Lake uranium-nickel ore deposits are located in the Athabasca Basin of northern Saskatchewan, Canada (Fig. 1). Many papers have been published on Key Lake in the past (Dahlkarnp and Tan, 1977; Kirchner and Tan, 1977; Kirchner et al., 1980). Immediately after its incorporation in 1968, Uranerzbergbau GmbH, a German holding company, set up exploration subsidiaries in Australia, the United States and Canada. This account reviews those exciting years starting with the concept to explore the rim of the Athabasca Basin in Saskatchewan, and leading up to the discovery of the deposits in 1975 and 1976.A few summary statements can be made:• The discovery of Key Lake resulted from a very systematic exploration approach and the persistence of Uranerz, the operator. • Cluff Lake and Rabbit Lake had been discovered some seven years before, but it was the discovery of the Key Lake deposits which brought Saskatchewan to the forefront to become Canada's foremost uranium producing province.• The experiences gained at Key Lake, which were subsequently published, triggered the discovery of many other deposits of similar, or even larger, size than Key Lake. The spatial relationship of those deposits to graphitic conductors and hydrothermal alteration zones are presently the most effective indicators for locating new deposits - indicators which were first recognized at Key Lake.• Key Lake is, and will remain for some years to come, the largest producing high-grade uranium mine in the world."

Jan 1, 1994

By J. J. Ferreira, M. L. Thurston, I. L. Chinn, D. M. Rose

"Concerns about using microdiamonds for resource estimation have been raised by workers because multiple diamond populations exist in many parts of the mantle source region, small diamonds in kimberlite could be exposed to proportionately greater levels of resorption and modification, and euhedral microdiamonds could crystallize immediately prior to kimberlite eruption. This paper addresses these concerns; discusses the geology of the mantle, the principal diamond host rocks, and the impact of mantle processes; compares micro- and macrodiamond properties and features; and outlines steps to identify and mitigate the risk of diamond resorption and its impact on the diamond grade-size relationship.RÉSUMÉ Des travailleurs se sont interrogés sur l’utilisation de microdiamants pour estimer la ressource; en effet, de multiples populations de diamants existent dans plusieurs secteurs de la région source dans le manteau. Des petits diamants dans la kimberlite pourraient être exposés à des niveaux proportionnellement supérieurs de résorption et de modification; de plus, des diamants idiomorphes pourraient cristalliser immédiatement avant l’éruption de la kimberlite. Le présent article traite de ces questions, discute de la géologie du manteau, des principales roches-mères des diamants et de l’impact des processus dans le manteau, compare les propriétés et les caractéristiques des micro- et des macrodiamants et définit les étapes pour identifier et mitiger le risque de résorption des diamants et son impact sur la relation entre la taille et la qualité des diamants."

Jan 1, 2016

By Paul Ransom

Sullivan Production and Present Value ? Mined 150 million tonnes ? 6.0% Pb, 5.5% Zn, 2 opt Ag, + Sn, Cd, In ? May 2006 Value + US$43 Billion ? 50% of metal from first 37% (55MT) of tons ? True original size ~ 110-120 Mt @ 17%Pb+Zn ? 30MT unconsolidated fill + HW cave

May 1, 2006

By A. Mellek, M. Pischtschan, M. Perrucci

ABB has received an order for one of the most challenging mill drive projects in its history. With one SAG mill and one ball mill to be added at an iron ore mine in Sweden, the customer’s plant managers wanted to have the most efficient solution for driving their mills but had the budget limitations typically faced by the majority of mining companies during periods of market downturn. To find the best balance between cost of acquisition and highest performance throughout the lifetime of the plant, ABB was selected to deploy a synchronized bypass solution, in which only one drive system is used for two different mills in series. However, being one of the first grinding mills in the world with such a solution was not the only challenge the ABB team faced: The inclusion of some mill application functions - e.g., frozen charge protection, automatic positioning and creeping mode - brought the demands on the engineers to another level. With only one frequency converter and one mill application controller available, the configuration logic and interlocks had to be meticulously designed and thoroughly tested to ensure a smooth and safe startup. The solution offers a footprint reduction and more operator flexibility at a reduced investment as each mill can be run in both directions, and wear on the mechanical components can be greatly reduced due to ABB’s premium ring-geared mill drive (RMD). This paper will describe the details of the project, the configuration developed and the tests performed to guarantee correct software functionality. Mill startup is scheduled for January 2016.

Jan 1, 2016

By Fulchand Shende

Around the world many potash mines experience brine inflow problems. The presence of brine in underground excavations may induce structural and stability problems. A study has been carried out to simulate the effect of brine on the performance of pillar support. The testing program consisted of loading potash specimens in a creep frame, and simulating inflows by continuously pumping brine into an experimental cell. Brine temperatures and load conditions were varied to simulate several mining and inflow conditions. Specimens were fitted with acoustic emission transducers to monitor energy emissions during an eight-hour test duration. Samples of brine were also collected to provide K+ and Na+ concentration data necessary for an accurate assessment of the dissolution process. Test results indicated that dissolution rates are highly dependent on brine temperature and load conditions. Loads approaching 50% UCS tend to generate very high rates of energy emissions, often leading to the failure of the simulated pillars. This study demonstrated that acoustic emission could be effectively used for predicting the performance of pillars when exposed to inflow brine.

May 1, 2001

By Thomas J. Ferree

"There has been a major evolution of mineral processing technology in the past decade. The evolution has been driven by recognition of broad environmental changes which have impacted various areas of the world. Numerous government regulations have required many mining and mineral processing organizations to introduce changes to reduce the undesirable effects on the environment; many mining companies have voluntarily introduced new technologies and practices which surpass the limits imposed by the regulations. Surprisingly, some of the 'new' technologies are modifications of concepts developed decades earlier. Gravity separation technology is in this category.Mineral Deposits Limited, an Australian company, has been a world leader in the development of mining concepts, reclamation practices and equipment technology that is environmentally suited to today's requirements. This paper relates to equipment used for gravity concentration and electrostatic separation systems, including Reichert cones, spirals, and electrostatic separators. The basic devices and technologies were developed more than forty-five years ago, but use of the systems was quite limited until environmental and conservation practices were recognized and introduced. Spiral concentrators, for example, were patented in the mid-l940s by I.B. Humphreys in Denver , Colorado. The two types of spirals marketed (the Model 24A for minerals and the Model 24C for coal) remained essentially unchanged until expiration of the patents. During this early period most spirals were used in iron-ore wash plants on the Mesabi Range to recover fine iron which previously had been discarded. About the same time sand mining plants in Florida incorporated spirals to recover titanium minerals and zircon from lowgrade beach sands. The Labrador Trough opened new opportunities for spirals when hard-rock iron-ore deposits were developed; approximately 10 000 Model 24A Humphreys spirals were installed between 1958 and 1966. About 5000 spirals of this model are still operating in the same capacity, in spite of the fact that extensive improvements have since been made in gravity separation technology."

Jan 1, 1993

By G. M. Ritcey, V. M. McNamara

"In the processing of gold ores by the cyanidation route, effluents which are discharged to the tailings areas can contain up to several hundred parts per million of cyanide in complex combination with similar quantities of heavy metals. Complicating this obvious problem of waste control are concentrations of thiosalts and thiocyanates which are roughly equivalent to the amounts of cyanide species. Although most gold mills are located in thinly populated areas, such contaminants can represent a potential environmental problem due to the various limitations exhibited by on-property ponding.The former Extraction Metallurgy Division of CANMET recognized the problem and, in early 1974, invited representatives of the gold mills to Ottawa to discuss the situation. At that meeting members of the Division presented a ""state of the art"" literature survey of cyanide abatement technology for waste solutions, together with preliminary cost estimate data(1). Shortly thereafter, Environment Canada, together with Environment Ontario, decided upon a guideline of 0.1 ppm (0.1 mg/l) total cyanide content as tolerable for an effluent stream which is discharged, in any manner, to the watershed."

Jan 1, 1978

From 1999 to 2008 rock related accidents accounted for 75 fatalities, nearly 6,000 injuries and almost 14,000 incidents (Pappas and Mark, 2011). Clearly this shows that rock related safety on coal mines remains a serious issue and more effort is needed to address this hazard. This paper reviews support design considerations and monitoring needed to improve rock related safety in room and pillar coal mines in the USA. From the present study design considerations continue to evolve and improvements in technology and a better understanding of failure mechanisms and methods to prevent these failures from occurring are in place. At first glance, the design of safe and efficient underground openings appears simple until the designer begins to realize the complexities and variability of geometries, geology, loading and stress influences, support designs and other factors such as corrosion and economics. Ultimately the goal of all designs is to ensure that it can be completed safely, last for the duration of the design life and it is economically feasible.

Aug 1, 2013

By A. B. Isaeva, A. Yu. Lein, A. A. Karpenko, V. V. Serova, A. P. Lisitzin, V. Yu. Rusakov, V. N. Lukashin

Abstract - The flux of sediment matter was determined using sediment traps near a black smoker ("Saracen’s Head," Broken Spur hydrothermal field) and the mineral and chemical compositions of the settled matter were examined. The metallic minerals are represented by Fe sulfides (pyrite and pyrrhotite), and Cu and Zn sulfides are also found in small and equal quantities. The hydrothermal suspended matter contains abiogenic calcite in amounts comparable to that in Ca sulfates. The content of silica and, specifically, of amorphous Si is unusually low. Such correlations between chemical elements and minerals, together with the isotopic compositions of S and C, are characteristic of a relatively young and active stage in the evolution of a hydrothermal system. Sediment traps within and under neutrally buoyant hydrothermal plumes collected biogenic material in addition to hydrothermal components. Microbial chemosynthetic production of organic carbon near the hydrothermal vent is comparable to primary production in the euphotic layer. Fe, Zn, Ca, Si, Ba and P are enriched in particulate matter in comparison to the background. A vast compound plume containing the discharge of multiple hydrothermal vents was found to the south of the Broken Spur hydrothermal field.

Jan 1, 1999

By Greg Collins

BUCKO EXPLORATION HISTORY ??1964-Discovery ??1970?s -114 holes totaling 34,000 metres drilled -vertical shaft excavated to a depth of 300 metres (1000 Level) plus 800 metres of underground development -Exploration program cancelled due to Falconbridge economic issues ??1990?S-19 holes drilled totaling 9,600 metres ??2000 -13 hole 4,600 metre exploration program by Nuinsco Res.

May 1, 2006

By Rene Klymowsky, Norbert Patzelt, Egbert Burchardt, Johann Knecht

"The challenge of ""ore bodies getting steadily harder and lower in grade"" was brought to light during the first oil crisis in the 70's. Shortly afterwards, HPGRs appeared on the scene with the promise of saving energy. This combined with developments in wear protection for the rolls ushered in a period of trade-off studies that considered the HPGR as an option to improve project economics or to even make projects feasible at all.Since then, applications of HPGRs at Cerro Verde (Freeport), PTFI Grasberg (Freeport), Mogalakwena (Anglo Platinum), Tarkwa (Goldfields), Boddington (Newmont), Penasquito (Goldcorp), and others have contributed to the creation of a formidable basket of operating experience. Collected through years of successful operation, this information has been used to validate design criteria, scale-up factors and establishing a clearer picture of what ""to do"" and what ""not to do"".This paper compares results from various mining operations using HPGRs in their processing plants. Some of the lessons learnt in different operating environments are reviewed in order to support proper implementation and operation of HPGR's. Some of the development programs that have been initiated to improve wear life of the tyres and to reduce overall operating costs are reviewed. It is timely to summarize today’s experience and analyse its implications for existing and new operations"

Jan 1, 2012

By George R. White

"The Phalen Colliery, the Cape Breton Development Corporation's flagship, is now producing thermal and metallurgical grade coal in Eastern Canada's Sydney Coal Field. The colliery is a drift mine operating under the waters of the Atlantic Ocean. Improved mechanization, including a 2200 tonne per hour cable conveyor, and the introduction of modern retreat longwall mining methods as part of the Phalen concept are now paying off in better productivity and low operating costs. Geological conditions within the coal field are consistent with plans for ever greater outputs in the 1990s. Although much of the current production improvement is related to uprated machine capacity and simplified mines planning there is potential for even further development in the areas of maintenance, process control and engineering. Human resource development will also be a key factor. These programs are now well under way and Phalen Colliery is poised for top results in the 1990s. Comparison of the CBDC's top producer with similar operations elsewhere in the world, quantifies that potential.IntroductionAn exciting new mining project which has recently started production on Canada's East Coast has been conceived and designed to be one of the most modern and productive coal mining operations in North America.As with all mining operations, the business is basically that of material transportation. Daily, the product is transported many kilometres from the underground face to the surface and then to washing facilities. Men, materials and equipment are transported to and from the surface and the operating faces and services, such as electrical power, ventilating air, fresh water, discharge water, communications and compressed air are supplied throughout the operation to cover operating requirements. On all accounts the operation has been designed to take advantage of the latest proven technology."

Jan 1, 1990

By K. L. Ford, D. R. Lentz, J. H. Rickard, R. P. Taylor

Abstract - Coupled gamma-ray spectrometric and lithogeochemical studies throughout the Heath Steele Mines area, Bathurst Camp, New Brunswick, indicate that primary and secondary geochemical differences exist between the stratigraphic footwall and hangingwall crystal tuff units which host the massive sulfide deposits. Of particular interest is Th, and to a lesser extent, Zr and Y, which are more concentrated in the hangingwall than the footwall crystal tuffs, whereas the opposite is true for TiO2. This expands on earlier lithogeochemical-chemostratigraphic results concentrated in the eastern part of the Heath Steele belt that led to revision of the local stratigraphy, and necessitated a structural re-interpretation of the area with implications for exploration. Although K depletion (decreased K and K/Th) is typical of chloritized footwall zones of chloritization, these features were not fully apparent here due to the recessive nature of these altered zones. In situ radiometric analysis using a portable gamma-ray spectrometer is a rapid, inexpensive analytical technique for chemostratigraphic characterization of rock units within volcanogenic massive sulfide deposit settings, provided there is a contrast in the distribution of natural radioelements, particularly Th and K.

Jan 1, 1998

By Claude Bazin, François Robichaud

The control of the operation of a semi autogenous grinding mill is mainly based on power and bearing pressure measurements. Image based sensors can provide on-line measurements of the size distribution of the ore feeding a SAG mill allowing the control of this variable that impacts the operation of this equipment. This paper investigates the potential of using the information from such type of sensor to maintain a SAG mill feed target size distribution by manipulating the speed of the ore extractors below an ore stockpile. A PID and adaptive predictive controller for the size distribution are studied using a simulator for a stockpile and the equipments used for ore withdrawing from the pile. The proposed controller is found to give a good performance while remaining easy to tune.

Jan 1, 2014

By X. Cao, X. -G. Chen, K. Liu

As is well known, the standard Al-Cu 206 cast alloys have extremely low iron contents, usually less than 0.15 wt. %. Recently it is found that the iron contents of the 206 cast alloys can be extended up to 0.5 wt. % through the precise control of the iron-rich intermetallic phases. In the present work, the tensile fracture surfaces of the 206 cast alloys with various iron contents are systematically analyzed to understand the failure mechanisms. Results show that higher iron contents can reduce the tensile properties (especially the ductility) of the alloys mainly due to the increasing volume percent and size of the iron-rich intermetallics. Tensile failure mainly occurs at the iron-rich intermetallics/matrix interfaces for the platelet ß-Fe, but by the self-disassociation for the Chinese script a-Fe and Alm(FeMn). Cracking is easier to initiate and propagate along the longitudinal axis of the platelet intermetallics, but it can be deflected along the branches/arms of the Chinese script iron-rich phases, making the alloy more resistant to the propagation of the cracks, and thus the Chinese script iron-rich intermetallics are less harmful than platelet ß-Fe. In addition, it was also found that the Chinese script a-Fe has even a less damaging effect compared to the Chinese script Alm(FeMn) due to the relatively small size and compact morphology.

Jan 1, 2014

By Masashige Makifuchi, Hiroki Kumakura, Kota Nagai, Takahiro Kikuchi

"A large amount of platinum group metals (PGM) are used in automobile catalyst. It is important to recover the metals from wasted catalyst. Nomura and Kageyama (2013) suggested recovery process that PGM oxides were absorbed to perovskite-type oxide based on LaScO3. In their process, the PGM in wasted catalyst as absorbed to the perovskite-type oxide as PGM oxide. It has potential to each element in the process if the perovskite-type oxide is selected properly. In this study, the PGM oxide absorption properties of various perovskite-type oxides are investigated to develop a new recovery and separation process. The various perovskite-type oxide were synthesized with metallic platinum, palladium, rhodium at high temperature in air atmosphere. And the PGM contents in the perovskite-type oxide after the experiment are determined by chemical analysis. Some of them have the properties to absorb specific PGM oxide selectively. In addition, in order to increase the amount of absorption of PGM oxide and composition of the perovskite-type oxide experimental temperature was investigated. Then it is also found that doping another specific element to the perovskite-type oxide is effective to increase the amount of absorption of PGM oxide. Then a new recovery process of PGM from wasted automobile catalyst, in which PGM can be separate to each element, was designed.INTRODUCTIONA large amount of Platinum (Pt), Palladium (Pd), and Rhodium (Rh) are used in automobile catalysis (Figure 1) (Platinum, 2013). Natural supplies for these metals are limited and PGM mining can detrimental environmental impact. Therefore, the recycling of PGMs from wasted automobile catalysis is very important. The Rose process (Figure 2) was developed as a process to recover PGM from wasted automobile catalysis. In this process, the automobile catalysis is first crushed mechanically, and then extracting agent, copper (Cu), and flux are melted at high temperature. The mixture separates into a metal phase, (Cu alloy containing PGM) and slag. The PGM is enriched by oxidizing. Cu to Cu oxide. The PGM are then recovered and separated to each element in a wet process. However, it is hard to dissolve the PGM with acid because they are chemically stable and strong oxidation agent such as aqua regia is used. Moreover, to separate the PGM to each individual element, a solvent extraction process is required."

Jan 1, 2016

By Louis R. Bernier

Most systematic studies carried out on passive treatment systems incorporating the use of limestone drains, under aerobic or anaerobic conditions, essentially deal with the treatment of effluents from mines in the USA. A limestone drain typically comprises a trench filled with crushed limestone rocks surrounded by impervious materials. In the case of anoxic drains, the trench is generally isolated under a geomembrane liner covered with soil. Contaminated mine effluents flow by gravity towards these limestone drains where the passive treatment consists in bringing the carbonates into solution, thus increasing the pH and alkalinity. Factors to be considered in the design are: chemistry of the contaminated mining effluent ([metals, [Al], [sulfates], dissolved oxygen, acidity, pH), desired residence time, nature of the rock, grain size, density, void ratio and mass of the limestone rock used, alkalinity, life span and hydraulic behaviour of the drain. Certain secondary effects (saturation by sulfates, co-precipitation, adsorption) may either be beneficial (lowering the sulphate and metal load) or harmful (armoring the limestone rock and clogging of the drain). This paper gives a brief status report on the available knowledge on the use of limestone drains for passive treatment of mining effluents heavily loaded with metals. Examples given include the old Lorraine mine (Ni-Cu), Témiscamingue, where limestone and dolomite rock drains were installed in 1998 when a cover with capillary barrier effects was placed over the tailings site.

Nov 1, 2002

By Paul Clayton

Case Study ? Site: BMA Saragi Coal Mine Queensland Australia ? Model: Marion 8050 ? YOM: Mid 1970s ? Boom: 97M ? Bucket: Original capacity of 100 Tonnes upgraded to 125 tonnes at time of filtration upgrade. ? Apps: Swing, Hoist & Drag Gearboxes ? Oil: Oil Castrol Alpha TT1200 Viscosity of 1208 cSt @ 40° C (104° F) 720ltr Oil Volume Trial and Installation Justifications ? To reduce gearbox overhauls. Typical schedule being 5 years. ? Bucket upgrade from 100 tonnes to 125 tonnes. Increased gearbox demand and stress. ? Increase of overhauls out to 10 years + ? Saving per Dragline estimated to be US$8-10M in downtime and maintenance if successful. ? In compliance with BHPBilliton Global Maintenance FLAC program ? Fuels, Lubricants, Air and Coolants ? Cost Justification ? Downtime: 4 days ? Lost production: $420,000 ? Cost of parts: $162,000 ? Labour and misc: $41,000 Gearbox failure cost $623,000

May 1, 2008

By Marc Tardif

"The way alarm information is provided to an operator can make a huge difference in the minutes following an upset. Process alarms are often looked at as a way to help avoid catastrophic failure and serious accidents. But knowing that mineral processing is so energy consuming and that raw material is not consistent, all small upsets should also be seen as a catastrophe because they can have significant impact on product cost and quality.This paper will demonstrate how it is possible to use data from process alarms to provide operators with real time, value added information that will help them take the right decision at the right time and in turn, reduce unplanned downtime by 20 to 80% and incidents by up to 50% (number and cost),and optimize energy and capacity usage.In the era of Big Data, living in a world where we are submerged with information, one of the biggest challenges is to find the right information at the right time.Alarm rationalization projects will often focus on alarm quantity, but alarm quality is also very important. It is possible, by following a simple 6-step process to turn “alarms” into truly valuable information for operators. Based on known standards (ANSI/ISA 18.2 and EEMUA 191), this process will capture the knowledge of the best and most experienced operators and process engineers, and make it readily available to everyone, right on time, when it matters the most.INTRODUCTIONWhen spending some time in a modern control room, it is easy to notice the huge quantity of information that is available to the operator. Modern operation stations feature multiple screens with HD capability. These screens display information like process display, history trends, alarms and events list, maps with geo-located information, images from live cameras, etc. However, it is harder to assess whether all this information is really helping operators: Is all the information relevant? Are process screens overcrowded? Is the information easy to understand? Does the operator know what to do with all the information? Are there too many alarms?"

Jan 1, 2016