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By S. C. Langvik

The presentation named 'Dewatering of fines by Rotary Vacuum Disc Filters' has an opening why the filtration process is important to the Iron Ore Industry. It goes on to describe the various types of dewatering machines which have been used in this industry in the last 30-40 years, and where the vacuum disc filters now dominates. It presents also the most important design changes which have been made during this period to enhance performance. Further are discussed the principles of filtration and the factors and parameters which influence performance and operating costs. As a closing is presented today's ideas and thoughts about what can be foreseen of design modifications and improvements in disc filter design in the coming ten years.

Jan 1, 2001

By Antti J. Perala, Teemu J. Yli-Kovero

"Efficient use of land is constantly requiring more underground construction. Minimized execution time and disturbance to surroundings and nearby structures are essential benefits for all construction techniques. To meet the demands of a modern construction project, suppliers have to be able to provide high-quality and tailor-made products just on time. RD pile wall is a retaining wall based on drilled steel pipe piles which are connected to each other with special interlocking profiles. RD pile wall is a solution which enables penetration of overburden soil, dense fill layers including stones and boulders, and embedding into the bedrock in one single operation. Several test installations and laboratory tests have been made to develop the system and to test and improve the water tightness of the wall. Beside these tests, RD pile wall has also proven its reliability in almost 70 projects. Largest project so far has been Pasila Tripla project in Helsinki, Finland. A permanent retaining wall with surface area of 18,000 m2 (193,750 ft2), excavation depth of 21 m (68 ft) and over 17 m (56 ft) of water pressure was made with 711 mm (28”) and 406.4 mm (16”) pile sizes. Piles were delivered to site in one piece with lengths up to 33.5 m (110 ft).INTRODUCTIONExcavations in cramped city centers and in between of existing buildings and other structures are facing more and more challenges. Installation of sheet pile walls is often problematic or even impossible due to obstacles in ground from old structures and due to demand to extend the excavations to even deeper and harder soil layers. Also installations of secant pile walls are facing difficulties due to cramped construction sites and constantly tightening execution times.On the other hand, an efficient and reliable piling technique suitable for the demanding soil conditions described above, percussion drilling, has been developed since the 1960’s, and especially from the mid- 1990’s, when the concentric drilling method with the ring bit and pilot was introduced. A new retaining wall application, the RD pile wall, was developed by combining that drilling method with the widely used retaining wall solution based on steel pipe piles and welded interlocks (a pipe pile wall normally installed with vibratory or impact hammers).PRINCIPLE AND MAIN BENEFITS OF THE METHODRD pile walls can be used in all soil conditions. Most beneficial the system is in extremely demanding soil conditions where the installation of traditional retaining walls is challenging or even impossible. The RD pile wall is a combination of drilled steel pipe piles and interlocking sections as shown in Fig. 1.Individual RD piles are connected to each other with interlocks welded to the piles on the automated welding line at the workshop. The matching dimensions of the drilling system and interlocking sections allow the installation of RD piles through stones and boulders and even into the bedrock, if necessary, in a single operation. Installation is done by a down-the-hole (DTH) hammer using the centric drilling system and oversized ring bits or a drilling system consisting of a pilot bit and reamer wings shown in Fig. 2."

Jan 1, 2017

By C. Cornejo, C. Schuffeneger, J. Rosas

"At the end of 2010 the AMSA Esperanza Concentrator started commissioning. Located in the Atacama Desert this project is the first of several large size concentrators developed recently to operate in Northern Chile. In addition to the new operations to be implemented in the short term, many existing installations are planning expansions. The use of large size equipment is one of the common characteristics of the new concentrators, but also new technologies are being considered and innovation is present in most cases. Sea water or desalinated water will be required to process large tonnages of sulphide copper ores as well as gold bearing ores, since process water supply from the Andes will no longer be available. The high cost of sea water or desalinated water supply and the high cost of energy are not a limitation as the current metal market scenario allows obtaining an attractive NPV even from installations designed to process relatively low grade ores. A review of the current concentrators being developed in Chile is presented, including a description of the main design issues related to technology and innovation. An analysis of the Chilean mining industry is also presented, detailing mine and plant capacities as well as expected final products.INTRODUCTION The mining sector in Chile has become a reference when analysing the large concentrator plants projected or currently in operation all over the world. At present and as a consequence of the high price of metal commodities, most South American countries have an active mining sector. Chile is known as a major producer of metals. First records of copper production exported to Spain are dated to the early XVII century. Since then Chile has produced over 13% of the total copper ever produced in the world. After 1990 Chilean mining and the associated cluster of activities has substantially grown to levels never reached before, especially in the production of copper, gold and other non-metallic minerals. This dramatic increase is the result of an economic policy based on delivering comparative advantages and incentives for the admission of foreign capital to offset the weak domestic investment in previous decades. Massive mining of its huge mineral resources has allowed Chile to be a world leader in the production of copper and other base metals and mineral products."

Jan 1, 2012

By A. J. Geldenhuys

This paper will focus on two topics, namely (1) an innovative process for the neutralization and partial sulphate removal of acid streams produced during coal mining and processing and (2)optimization of this integrated neutralization process by adding small amounts of synthetic organic polymers. The integrated lime and limestone process has been developed to neutralize acid mine water and to remove sulphate (to less than1 200 mg/l), magnesium and metals. Limestone and lime treatment is the most cost-effective technology for neutralization and partial sulphate removal of acidic/sulphate-rich water to sulphate levels of less than 1 500 mg/l due to precipitation of magnesium and removal of the associated sulphate fraction (through gypsum crystallization). Neutralized mine water of this quality may be suitable for irrigation. The process consists of the following stages: 1. Limestone (CaCO3) neutralization to raise the pH to 7 and CO2-production. 2. Lime (Ca(OH)2) treatment to pH 12 for Mg(OH)2precipi-tation and gypsum (CaSO4.2H2O) crystallization. 3. pH adjustment with CO2recovered from stage 1 and CaCO3 precipitation. Retention times of 1 hour, 4 hours and 1/2an hour were required by stages 1, 2, and 3 respectively. The sulphate level was reduced to 1 094 mg/l, which is less than the original aim of 1 200mg/l. Chemical costs associated with neutralization, using limestone instead of lime, are reduced by 69% in the integrated limestone/lime process. The overflow water from the clarifier of each of the above stages generally contains a wide variety of colloidal impurities that may cause the water to appear turbid or may impart colour. This results in very slow sludge settling rates that cause overflow water with a high degree of turbidity and colour. There are a number of successive or simultaneous stages involved in the agglomeration of particles. To get optimum neutralisation of the acid water and partial sulphate removal to below the saturation level of gypsum (i.e. 1 500mg/l), maximum sludge recovery is needed. The higher the concentration of seed crystals, the larger the surface area. Therefore, effective removal of suspended and colloidal matter from the overflow of each stage is required and can be achieved by coagulation and flocculation. The polymers PAC6 and 3095 were effectively used as coagulant and flocculant respectively. The addition of these polymers resulted in a clear overflow in each of the above stages with a very low turbidity.

Jan 1, 2003

By J. Kendall Hales

Jan 1, 2005

By G. G. le Roux

The purpose of the investigation was to assess various options for increasing the efficiency of the conveyor belt transporting system used at 4 Belt Shaft at Lonmin?s Marikana operations. The reason for the investigation was to prevent the occurrence of a ?bottleneck? at the main ore passes delivering ore to the conveyor belt system, thus creating more fluent operational conditions. The options assessed for increasing the efficiency of the conveyor belt transporting system were: ?Variation of the conveyor speed ?Concurrent tipping from two ore passes on the belt ?Increase the available drive unit power ?Increasing the feed rate from vibratory feeders ?Change in belt width/belt specifications The report shows that the most preferable option to the current situation at 4 Belt, Lonmin, would be the option of concurrent tipping from two ore passes to the belt.

Jan 1, 2008

By D. Schreuder

Conditions in the South African market relating to atmospheric emission control has changed dramatically over the last 10 years. Companies have become more responsible, environmentally aware, and have to comply to more stringent environmental limits set by legislation. This paper describes briefly the current best available atmospheric pollution abatement technologies relating to particulates, acid gases, NOx, acid mists, aerosols, mercury, dioxins and furans. Mention is also made as to the best practices for product work-up and waste product disposal.

Jan 1, 2006

G. R. Compton (Gold Mines of Kalgoorlie (Australia) Ltd., Fimiston, W. A.) : In congratulating Mr. Hooker upon his resume of Mr Parry's paper I have in mind the fact that he carried out the research into pipe pressures. Hydraulic filling as practised in Kalgoorlie has created world wide interest, with these pressures and percolation being vital points.Early in the 1950s, representatives of the Kolar field were conduGted over the local mines where stopes at depths below 2,000 ft were being filled. The problems of pipe pressures were their main consideration since depths of up to 10,000 ft were envisaged.Mr Krishnaiah and Mr Murthy from the same field are with us today and perhaps we may hear of their experiences with depths of 6,000 ft and long lateral lines.J. Holly (Lake View and Star Ltd., Fimiston, W.A.): There is one phase, which I would like to mention myself, that has been very evident in Kalgoorlie operations. That is, we do not get the percolation properties that are obtained on many other fields in the world, and our tendency here has been to assess the quality of our fill more by its settling rate, i.e. the rate at which we can draw off clear water at the surface of the filling levels, rather than the rate that this water percolates down through the fill before it consolidates.We are tending now to measure the quality of our fill as a settling rate rather than as a percolation rate.Americans talk about percolation rates being the important property: If anyone has any experience on operating with fills with different percolation rates, I think their views would be very interesting to the meeting art this stage. Mr ...

Jan 1, 1965

By K. Webb, M. Hohn

"This paper reviews the evolving Ontario mining regime for mining industry-Aboriginal engagement and its apparent alignment with court decisions, domestic law, emerging international norms, mining industry rules, and mining firm-Aboriginal agreements, drawing on publicly available commentary from government officials, the private sector, and Indigenous communities. This paper provides a preliminary analysis of the potential implications of the new regime, especially for the mining industry and Aboriginal communities and, on that basis, discusses possible future developments.RÉSUMÉ Le présent article analyse le régime minier de l’Ontario pour l’engagement entre l’industrie minière et les Autochtones et son harmonisation avec les décisions des tribunaux, le droit interne, les nouvelles normes internationales, les règles de l’industrie minière et les ententes compagnies minières- Autochtones en se basant sur des commentaires, disponibles publiquement, d’officiels gouvernementaux, du secteur privé et des communautés autochtones. Cet article fournit une analyse préliminaire des implications potentielles du nouveau régime, surtout pour l’industrie minière et les communautés autochtones et, en s’appuyant sur ces données, il traite des futurs développements possibles."

Jan 1, 2016

Refractory gold ores have been the subject of intensive metallurgical study in order to achieve more efficient recovery of contained values and at the same time to minimise environmental impact. Considerable innovative gold processing technology was introduced in New Zealand last century, the most notable being the first successful commercialisation of the cyanidation process by the Crown Mines Company at Karangahake in 1889. The Karangahake gold-silver deposit was second only +to the Waihi Martha mine in total bullion production from the region with active mining from 1882 until about 1920 and sporadic production between 1930 and 1944. Reevaluation at Karangahake with associated metallurgical testing has continued since that time becoming particularly active in the last decade as a result of increasing gold prices. Gold processing technology is reviewed and results of some recent test work are presented and discussed in the context of Karangahake history and future development possibilities. This work confirms the variability and complexity of the Karangahake deposit both mineralogically and metallurgically and suggests flotation followed by new and innovative smelting is the most appropriate processing route for the recovery of gold from the high grade ore which could be produced from the Karangahake workings in moderate tonnages.

Jan 1, 1993

A systematic study of groundwater conditions at eight underground mine sites exhibiting a wide range of groundwater qualities throughout Australia has been completed at the WA School of Mines. This has resulted in a new corrosivity classification for groundwater driven corrosion processes for cement grouted cable strand used in the Australian underground mining industry. The new corrosivity classification is simple to use and corrosion rates may be predicted from readily obtained in situ measurements of groundwater dissolved oxygen.

Jan 1, 2008

By W. F. Van Impe

The design of piles and of pile groups has remarkably progressed over the past two decades. The in­creasing complexity of the building concept implements a more rational approach of the deep foundation capacity and its interaction with the structure. Moreover, the understanding of the soil characteristics relevant to deep foundation behaviour, is continuously in progress because soil parameters are always more accurately determined; which also contributed a lot to the recent developments in pile capacity design. At last, due to the increasing sensitivity of buildings to deformations, continuous attention must be also paid to pile group settlements. The aim of this report is to discuss some of the mentioned more important pile design developments.

Jan 1, 1994

"Editor’s note: Each year, Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals and Aggregates Division technical committee chair and vice chairs, and to the authors of the individual commodity profiles.Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor.Vishal Gupta, member SME, of EP Minerals LLC, is chair of the Industrial Minerals &Aggregates Division’s Technical Committee.The technical committee vice chairs include:• Vishal Gupta, member SME, of EP Minerals LLC, Agricultural Materials.• Joe Garska, member SME, of Imerys, ceramics and refractory materials.• Stanley Krukowski, member SME, of the Oklahoma Geological Survey, chemical raw materials.• Russell Winn, member SME, of R.E. Janes Gravel Co., chemical raw materials.• Justin Zdunczyk, member SME, of Pike Industries, construction aggregates.• Jerry Gauntt, member SME, of Golder Associates, fillers and pigments.• Ebrhaim K. Tarshizi, member SME, of the Michigan Tech, sorbents, filters and process aids.• Daniel T. Eyde, member SME, of St. Cloud Mining, specialty minerals.Their help makes possible this July industrial minerals issue. On behalf of ME readers, the editors thank them.Virta, R.L. U.S. Geological Survey, National Minerals Information CenterFour companies - H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co., and Unimin Corp. - mined ball clay in four states in 2013. On the basis of preliminary data, production was 1 Mt (1.1 million st) with an estimated value of $47 million. Production increased by 3 percent in tonnage from 973 kt (1.1 million st) with a value of $45.1 million in 2012. Tennessee was the leading producer state accounting for 64 percent of domestic production, followed by Texas, Mississippi and Kentucky. About 67 percent of total ball clay production was airfloat, 22 percent was crude or shredded and 11 percent was water-slurried.ConsumptionIn 2013, domestic ball clay producers sold clays to the following markets: ceramic floor and wall tile (44 percent); exports (21 percent); sanitaryware (18 percent); miscellaneous ceramics (9 percent); fillers, extenders, and binders, and unspecified uses (4 percent each), based on 2012 end use patterns and current markets. Other markets accounted for less than 1 percent of the remaining ball clay sales or use. Sales reported for the manufacture of fiberglass or most filler, extender, and binder applications were likely to have been mainly kaolin mined or purchased by the ball clay producers.PricesThe average value of domestically produced ball clay was approximately $47/t ($43/st) in 2013 compared with $46/t ($42/st) in 2012, on the basis of a preliminary survey of domestic ball clay producers. The unit values of exported and imported ball clay were $126/t ($114/ st) and $373/t ($338/st), respectively, in 2013, compared with $62/t ($56/st) and $314/t ($285/st), respectively, in 2012. Unit values for most large export shipments increased in 2013, and a larger number of low-tonnage, high-value export shipments were shipped in 2013 than in 2012, resulting in a doubling of the average export value. Two low-tonnage, high-value shipments in 2013 accounted for the increased value of imports."

Jan 1, 2014

By James D. Noll, Jon A. Hummer, Shawn E. Vanderslice, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health designed and conducted a study in an underground metal mine to assess the effects of selected diesel emissions control technologies on the concentrations of diesel particulate matter and gases in underground mine air. The control technologies studied included diesel particulate filter (DPF) systems, filtration system with disposable filter elements, diesel oxidation catalytic converter, and biodiesel blends. Each technology was tested on a mining vehicle operated in an isolated area of an underground mine supplied with fresh air. These isolated zone tests allowed for the operation of vehicles under conditions and over duty cycles that closely mimic actual duty cycles of production equipment. The DPF systems reduced the elemental carbon (EC) concentrations in mine air between 88% and 99%. The same systems reduced total particulate matter (TPM) concentrations in mine air by approximately 75%. The biodiesel blends B20 and B50 caused a reduction in the EC concentrations of 26% and 48%, respectively. Those blends also reduced TPM concentrations by 9% and 24%, respectively. The use of #1 diesel fuel reduced EC concentration by 13% compared to #2 diesel fuel. An increase in nitrogen dioxide concentration of up to two times was seen when platinum-catalyzed DPF systems were tested.

Jan 5, 2006

By R. A. Cattell

A technologic group such as the Petroleum and Natural Gas Division of the Bureau of Mines, which conducts research on many of the complicated and frequently interrelated problems of extracting crude oil and natural gas from the ground, transporting them to market or to places for subsequent treatment, and manufacturing products, should report progress from time to time. Engineers and others who apply the results obtained by this division are closely associated with its personnel, because may of the problems are attached cooperatively with groups in industry. Some of this cooperation is formal, as exemplified by work now in progress under cooperative agreements with the States of Oklahoma, Kansas, and others, but much of it is informal, prompted by the desire to be mutually helpful in the public interest. Furthermore, the published reports of the Bureau on subjects pertaining to petroleum and natural-gas technology come to the direct attention of a relatively large number of persons, whose interest in results and appreciation of the value of this type of work have caused them to be kept currently informed regarding available data.

Jan 1, 1940

The prospect of utilisation of phosphate ores which contain high P2O5 values associated with Al and Fe has produced a great deal of interest over many years. Processing options have generally been based on the utilisation of by-products which were required to offset the processing costs.   This paper presents a range of processing options which have been investigated at laboratory or technical scale on phosphate ores which predominantly consist of crandallite, CaAl3(PO4)2(OH)5.3H2O and millisite, Ca(NaK)Al6(PO4)4(OH)9.3H2O. Christmas Island (Indian Ocean) and Mt Weld (Western Australia) phosphate ores are good examples of such feedstocks. It is expected that these processes may also be applicable to such phosphate ores from other locations.

Jan 1, 1990

By R. A. Cattell

A technologic group such as the Petroleum and Natural Gas Division of the Bureau f Mines, which conducts research on many of the complicated and frequently interrelated problems f extracting crude oil and natural gas from the ground, transporting them to market or to daces for subsequent treatment, and manufacturing products, should report progress from time to time. Engineers and others who apply the results obtained by this division are closely associated with its personnel, because many of the problems are attached cooperatively with groups in industry. Some of this cooperation is formal, as exemplified by work now in progress under cooperative agreements with the States of Oklahoma, Kansas, and others, but much of it is informal, prompted by the desire to be mutually helpful in the public interest. Furthermore, the published reports of the Bureau on subjects pertaining to petroleum and natural-gas technology come to the direct attention of a relatively large number of persons, whose interest in results and appreciation of the value of this type of work have caused them to be kept currently informed regarding available data.

Jan 1, 1940

By D. E. Wolfson

As part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report.2/ The suitability of coal for metallurgical use depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, as well as the available reserves, are considered in selecting coals for carbonization tests. According to the estimate of reserves by Dowd,3/ the recoverable coal in Raleigh County in beds 28 inches or more thick, in thousand tons, is: [ ]

Jan 1, 1957

By Frank G. Wickert

One key to maintaining successful mining operations in today?s global economy is in having the ability to access real-time machine operating data ([1] G. Brown, B. Ebacher, W. Koellner,2000)([2] Brochure of Siemens E&A, Order Number 141000-1). With recent and ongoing advances in mining equipment systems it is imperative that mine managers have full knowledge of the status of their equipment at any given point in time. This knowledge is critical to ensuring that the productivity of each and every machine is maximized. Knowledge of machine status is only the first step, however, in controlling and optimizing a piece of mining equipment. Computer based diagnostic systems, traditionally offered on mining equipment, have provided a link for collecting data and trouble-shooting problems as they occur. One problem existed, though, that those systems stopped short of providing full drive systems access. A maintenance technician could see the data but to make critical adjustments or make repairs the technician needed to be on the machine. In extreme cases the machine would be down until OEM assistance could reach the mine site. The key then to reducing down-time and maximizing machine productivity was creating a system that could not only monitor drive systems but also provide remote access to those systems. Essentially a link needed to be created through which a technician could gain drive access remotely then make adjustments or repairs without being on the piece of equipment. This paper will introduce AccessDirectTM, a new remote diagnostic system for Bucyrus mining shovels and draglines. AccessDirectTM combines all three important elements of remote diagnostics: ? Vital Signs and Production Monitoring (SiRAS-M) ? Automatic analysis (SiRAS-A) of faults, and tracking of trends for preventive and reliability centered maintenance , and ? Fast, direct Intervention (SiRAS ? I) for troubleshooting support, repairs, and system optimization.

May 1, 2002

By G. Bartolacci, G. Couture, Levasseur. B., A. Lockhart, D. Nathan

"Pulp and froth zone characterization in a flotation circuit to improve transport of valuable minerals remains a challenge. Even though some significant breakthroughs have been made in the development of collectors in terms of selectivity, the control of gangue drainage is still the main bottleneck to achieve the production of a clean concentrate.Over the last decade, COREM’s team has been working on technologies to improve the selectivity of flotation circuits by tuning their hydrodynamic conditions using online instruments such as the bubble viewer, Jg sensor and gas hold-up. As part of its research program, COREM also developed the half-life column that establishes the relationship between the collection zone (bubble-particle attachment) and the cleaning zone (foam) of a flotation machine. In recent years, COREM has continued the development of the prototypes to make them more robust and improve the accuracy of their measurements.Recently, these hydrodynamic instruments were installed in an industrial process at Raglan Mine in order to diagnose and control the impact of hydrodynamic parameters versus the recovery and the quality of the Ni concentrate produced. Sampling campaigns of hydrodynamic parameters demonstrated that froth height could be optimized in order to increase recovery and quality of the concentrate at the same time. The specific effect of the froth height impacts both the pulp and the froth zones. Along with the impact on the drainage of the concentrate, it was observed that froth height also contributes to enhance the collection of particles in the pulp leading to an increase in metallic units.IntroductionOnce the particles of the minerals of interest are attached to the air bubbles injected in the pulp, the flotation process is driven by air dispersion parameters and froth properties. The pulp is usually responsible for the collision between air bubbles and hydrophobic particles of interest while the froth zone aims to upgrade the selectivity of the particles floated through drainage of the unwanted hydrophilic particles. Over the last four decades, flotation hydrodynamics has been extensively studied. Superficial gas velocity (Jg), gas hold-up (eg), Sauter mean bubble diameter measurements (d32) and bubble surface area flux (Sb) are among the most assessed parameters in flotation plants worldwide either to quantify the gas dispersion parameters or to optimize them (Fournier et al., 2015). McGill University has developed several sensors able to measure these parameters at industrial scale (Tavera et al., 1996; Finch et al., 1999; Chen et al. 2001)."

Jan 1, 2017