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By L. R. Plitt, A. A. Turak, B. C. Flintoff

"Since the publication of empirical cyclone models by Lynch and Rao in 1975 and by Plitt in 1976, the technical literature on this subject has consisted primarily of reports of applications, with only a few articles discussing basic modifications or enhancements in model form. In fact, most of the modelling eff ort in this period has been concerned with theoretical models based on the hydrodynamics of multiphase flow. (Preliminary resutls have been encouraging, however, it will be some time before this approach reaches the practical application stage.) This paper presents a review of empirical cyclone modelling technology, with an emphasis on developments since the mid 1970s. The topics addressed include homogeneous and heterogeneous ores, parameter estimation techniques, parameter confidence intervals, and the introduction of a new conceptual model of cyclone operation.IntroductionSince their first reported application in the mineral industry by Driessen (1939), cyclones have become a common unit operation in all of the process industries. The widespread use of the cyclone stems from its relative low cost and its versatility. It can be employed to carry out liquid-liquid, solid-liquid and solid-solid separations. It is the area of solid-solid separation which is of greatest interest to a mineral processing engineer. Historically, this area was divided into two application categories: (I) Separation according to density, the cyclone washer, and, (2) Classification according to particle size, the cyclone ciassifier. (When water is the carrier fluid, the cyclone is more often called the hydrocyclone. For the purposes of this paper the two names are used interchangeably). Classification is the principal application in mineral processing circuit s. Within this category, the cyclone is most commonly employed to provide some positive control over the size distribution of product from a grinding circuit. Other uses include sand-slime separation prior to froth flotation and mill tailings treatment, either for dam construction or in backfill preparation."

Jan 1, 1987

By E. S. Shedd

Amenability studies were conducted by the Federal Bureau of Mines on an electrooxidation technique for the extraction of mercury from cinnabar ores, particularly those that are too low in grade to be furnaced or retorted economically. Oxidation was accomplished by electrolysis of the ore while slurried with brine. Mercury was dissolved through the formation of the soluble tetrachloro mercury complex, HgC142-. Mercury extractions ranged from 90 to 98 percent in 4 to 6 hours of processing time when tests were made on eight different types of cinnabar ores containing from 0.7 to 18 pounds mercury per ton ore. Salt concentration was varied from 4 to 10 weight-percent depending on whether Pb02 anodes and iron cathodes were used or whether graphite was used for both electrodes. Power consumption ranged from 17 to 64 kilowatt-hours per ton of ore treated. Ninety-nine percent of the mercury was recovered from pregnant solutions by precipitation on an active metal such as zinc, followed by distillation of the resulting amalgam at 600° C.

Jan 1, 1975

By William J. Neely

Augercast piles are formed by drilling a continuous-flight auger into the ground and, on reaching the required depth, sand-cement grout or concrete is pumped down the hollow stem as the auger is withdrawn. The sides of the hole are supported at all times by the soil-filled auger, eliminating the need for temporary casing or bentonite slurry. The augercast piling method is fast and economical; there is no vibration, very little noise and, if executed properly, no ground displacements during installation. The method is well suited to sands which are easy to drill and are readily transported up the auger. Relatively little attention has been given to augercast piles in the literature which might be part of the reason for the considerable variations in local practice, building code requirements and design methods. The purpose of this paper is to discuss some of the features of augercast pile installation that are known to influence both the structural and geotechnical capacity of the pile, to evaluate several empirical design methods and to look at some important aspects of quality control of augercast pile installation.

Jan 1, 1990

Experimental results are presented that test the hypothesis that the descaling behaviour of stainless steel slabs following reheating is controlled by interfacial roughening at the scale-steel interface. In this investigation, two stainless steels were considered: type 304 (austenitic, with 18% Cr and 8% Ni) and type 412 (ferritic/martensitic, with 11.6% Cr). It was found that the entanglement that arises at the scale-steel interface was in fact effective in maintaining scale-steel adhesion, under the mechanical descaling conditions used. In the case of type 304, descaling proceeded by fracture along chromite layers, which formed (by internal oxidation) on the austenite grain boundaries; for this steel, the extent of descaling depends most strongly on austenite grain structure, and not primarily on the conditions in the reheating furnace. In contrast, type 412 samples descaled only at the edge of the entangled zone, and showed a greater sensitivity to the reheating conditions; specifically, higher free oxygen in the reheating gas and longer reheating times were found to increase the residual scale thickness. Key words: stainless steel, reheating, scale, entanglement, descaling, fayalite, internal oxidation, grain structure, free oxygen.

Jan 1, 2003

By Salvador Gómez, Rodolfo Espinosa, Jaime Bravo, Leopoldo Gallas

"Compañia Fresnillo, S.A. de C.V. - Proaño Mine, is owned by Industrias Peñoles S.A. de C.V. (Peñoles). The Proaño Mine, is one of the richest silver underground mines in the World, and for this reason, production capacity has always being expanded, based on generated reserves. Reserve generation has not being an easy task as this is a vein type deposit.This paper presents the growing stages at the Concentrator, for about the last twenty years; which can be listed as follows:1.,Increase in capacity from 1,000 to 4,500 tonnes per day, at several stages; on the same infrastructure, and without production interruptions.2.,Addition of a new flotation circuit to recover a zinc concentrate with a high silver content.3.,Installation of a semi-autogenous (SAG) mill, to replace a conventional crushing circuit. 4.,Modernization. Installation of an on stream analyser, an automatic reagent dosification system, 4500 ft3 unit cells, pressure filtration, a closed circuit video system to help process monitoring, an automatic ball addition system for SAG and ball mills, and on-line particle size analysers.5.,Silver recovery from old tailings, installing a 2,350 tonne per day treatment plant.INTRODUCTIONIndustrias Peñoles, S.A. de C.V. (Peñoles)Peñoles’ mission is to add sustainable value to non-renewable natural resources. Peñoles seeks to: build long-term shareholder value; provide customers with the highest quality product services; maintain productive long-term relationship with suppliers; develop and promote the capabilities of their personnel; foster mutually beneficial relationship with the communities in which operates; protect and preserve the environment."

Jan 1, 2002

By M. Moseki

Paper written on project work carried out in partial fulfilment of B.Sc. (Eng.) (Metallurgy of Materials) degree This paper presents the research into melting of scrap for job creation purposes in rural areas. The research was done on behalf of Mine Recycling Services (MRS), the company that will implement the project. The project involves the research into available cost effective and easy to operate technology. The paper covers the experimental and theoretical work that was conducted. The results were used to determine the best equipment and method for melting and casting brass scrap.

Jan 1, 2002

A subsurface study of the Maria Lode and associated hydrothermal alteration of andesites within the Karangahake epithermal gold-silver deposit defined the local evolutionary sequence in the once active geothermal system.   Some implications for mining of epithermal deposits arise as a result.

Jan 1, 1984

By J. G. Haymes

This report by the Bureau of Mines is the first of two proposed papers on evaluation of spectrophotometric, spectrographic, polarographic, and other analytical methods for quantitatively determining impurities in high-purity tungsten. Some of the methods described are standard methods that have been successfully applied to determine low-level impurities, several are modifications of known methods, and some procedures are entirely original. The Bureau of Mines is actively engaged in tungsten research because tungsten has an extremely high melting point, in fact the highest of any known metal. The metallurgist must know the content of impurities in tungsten because of the marked effects even micro amounts of impurity elements have on its physical properties. The Bureau procured a number of analyzed samples of above-average purity from research laboratories of companies engaged in production and fabrication of tungsten. These samples were investigated by the analytical procedures of those companies for several metallic impurities. Subsequent analytical laboratory determination of impurities in these samples agreed with the analyses as reported. With this assurance that analytical methods were basically accurate for metallic impurities, procedures for the determination of several of these elements were modified to lower the limits of detection and increase the sensitivity of methods. Carbon and the gases hydrogen, nitrogen, and oxygen were determined by standard instrumental methods, modified to provide greater sensitivity for reliable determinations when content of these elements was low. After the reliability of the modified procedures was affirmed, they were used as a product evaluation guide in the development of a vapor-plating technique for the production of high-purity tungsten. The following list of elements can be determined by one or more of these methods: AI, B, Be, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, S1, Sn, Ti, V, and Zn. In addition, a vacuum-fusion method for the determination of H, N, and 0, and a conductometric method for carbon are described. Lower limits of determination and detection for each element listed are given.

Jan 1, 1962

By Steve Colbum

LTl’s MapStar LPS (laser positioning system) utilize both tripod mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environment characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, interactive software program, which can be run on any standard PC. Win Prof, the Windows-based analytical software package is used to reduce the data for generating bench face profiles, surfaces, volumes, estimating true burdens and mining ratio calculations. In addition, the software has many other built-in routines to calculate powder factors, toe shear, to map structural contacts and to predict the flyrock potential based on the Burden to Energy ratios. An extensive, built-in library of explosive’s data facilitates these calculations. It will also conform automatically to user-specified minimum and/or maximum burden in relation to the explosive energy, hole diameter and bench geometry - for both vertical and inclined holes. Numerical data can be represented in 2D or 3D to emphasize the hole-burden-face relationships.In this workshop, the MapStar LPS instruments and Win Prof analytical software will be thoroughly demonstrated. Demonstrations include equipment configuration, typical field setups and several effective survey procedures, including processing of some sample data.

Jan 1, 2000

By Ozgul Keles, Dila Sivlin

Lithium ion batteries are potential energy source of next generation electric vehicles (EVs). However, some problems such as safety, durability, low capacity, cycle life etc. restrict their use in EVs. These problems mostly related with cathode materials, an improvement in cathode materials may cause significant changes in battery performance. In this work, to overcome cycle life problem Al2O3 coating on LiNi0.5Mn0.3Co0.2O2 cathode material produced by sol-gel method. The surface modification of LiNi0.5Mn0.3Co0,2O2 was started by adding LiNi0.5Mn0.3Co0.2O2 powders into alumina sol. Then, sonication was started and two different sonication powers were tested (45, 100%). After the second gel is obtained, last heat treatment for Al2O3 crystallization was done at 600 °C for 4 h. X-ray diffraction (XRD) measurements showed that the material had a well-ordered layered structure and Al was not in the LiNi0.5Mn0.3Co0.2O2. Al2O3 coated materials show better cycling performance compared to the pristine material. It is believed that, this improvement is caused by the fact that Al2O3 layer prevents direct contact between active material and electrolyte and reducing decomposition reactions.

Mar 1, 2018

By Dominic Orf, Gregory Poole

On December 12, 2018 at 4:14 AM EST, an earthquake registering a 4.4 magnitude on the Richter Scale occurred in central Tennessee. According to a survey posted on the USGS website, this earthquake was felt throughout the southeast and even as far away as Arnold Nebraska. That’s over 900 miles (1,448 kilometers) from the epicenter. We recorded the vibrations from this earthquake on 44 different seismographs that were set up with remote access to continuously monitor vibrations from blasting activities. Having this data gave us an opportunity to compare the vibrations caused by earthquakes and blasting. A simple observation of the amplitudes, frequencies, and durations is enough to notice that vibrations from earthquakes are very different than vibrations caused by blasting in mining and construction. We were also able to observe the dissipation of the vibrations from the earthquake and see if the low frequencies, that are typical of earthquakes, dissipate at a consistent rate. Regression calculations were performed in order to see if there was a good data fit and if a specific vibration prediction could be made based on the magnitude of an earthquake. “How does quarry/mining/construction blasting compare to the Richter Scale?” This is a very common question that we get from homeowners when discussing vibrations due to blasting activities. This paper is intended to provide some simple answers for such a complicated question. Both the Richter and Mercalli scales are compared to the particle velocities as they were recorded from this earthquake.

By M Pepper, C R. Roche, G M. Mudd

"The Australian mining industries approach to life-of-mine planning has improved considerably in recent decades. It now needs to be matched by, and embedded in, mining governance systems that utilise a comprehensive whole-of-mine-life approach within a jurisdictional, industry and regional regime rather than just focusing on specific impacts in isolation. The need for a more comprehensive approach is supported by the many mining legacies, from historic, recent and some operating mine sites around Australia. There are sites that are leaving enduring environmental, community and public health impacts that are yet to be accurately assessed. While a number of these sites in Australia are estimated to be more than 50 000, this is probably an underestimation, with a lack of data and different state-based approaches complicating attempts to quantify mining legacies as a national issue. Qualitative assessments about the extent and nature of mining legacy impacts on nature and communities across Australia are also required if we are to understand and avoid ongoing and future mining legacies.This paper commences with an exploration of mining legacies as an umbrella term for previously mined, abandoned, orphan, derelict or neglected sites. This is followed by a discussion of the current status of mining legacies as an Australia-wide issue, contrasting the Australian response with overseas examples. Common themes from past workshops are explored recognising that mining legacies are a growing public policy issue and identifying key ingredients for a successful response. Supporting this, and based on national data which re-enforces the need for action, is the changing scale and intensity of mining in Australia that, while lowering costs for mine operators, increases the liability that may eventually fall to the state if mine sites are not rehabilitated effectively. Though a national issue, mining is a state and territory responsibility, so the current approach to mining legacies is then examined state-by-state. Given the widespread application and recent changes to bonds and levies in Western Australia (WA) and the Northern Territory (NT) the merits of both are examined with reference to specific case studies. Despite the current division of responsibility and diversity of approaches, however, mining legacies remain a significant and growing problem with a recognised need and repeated call for cooperation and coordination at a national and international level. Future action is addressed in the final section with reference to liability, responsibility, industry reputation, regulation and leadership.CITATION:Pepper, M, Roche, C R and Mudd, G M, 2014. Mining legacies – understanding life-of-mine across time and space, in Proceedings Life-of-Mine 2014 , pp 449–466 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By G. C. McLachlan

Two papers dealing with Noranda's milling operations have already been presented. The first1 of these covered the initial metallurgical problems connected with the treatment of the ore, while the second2 described the development of the mill from a 500-ton unit in 1928 to one with a daily capacity of 3000 tons less than six years later. At the time the second paper was written the equipment whirh had been installed to bring the mill capacity up to 3000 tons was being tuned into production and for this reason, though each step had previously been tested by a large-scale pilot operation, it was thought advisable to withhold metallurgical data until any starting-up difficulties had been overcome and anticipated requirements fulfilled. These requirements called for an improvement in gold recovery without any lowering of the previous ratio of concentration, and the pages that follow deal with the methods by which this result was obtained. An idea of the character of Noranda concentrating ore will be gained from an inspection of the following mineralogical analysis of the ore treated by the mill during 1933: MineRal Content Mineral ConteNt Chalcopyrite, per cent..... 6.8 Silica and silicates, per cent............ 18.3 Pyrite, per cent........... 22.1 Gold, native and as telluride, oz. per ton 0.15 Pyrrhotite, per cent....... 51.5 Silver, probably as argentite, oz. per tou 0.35 Magnetite, per cent....... 0.5 Thesr figures, which are typical, show that over 73 per cent of the ore treated consists of pyrite and pyrrhotite. Determirnation of the proportion of unrecovered gold associated with each of these minerals was therefore of primary importance in developing a suitable method for improving gold recovery. As pyrrhotite is magnetic, this information was obtained by making magnetic sorting tests on samples of the mill tailing and screening the material thus segregated. This showed that the magnebtic material finer

Jan 1, 1935

By Robert Keyes, Charle Knowles, Glenn Kendall, Gary Fletcher

"The metal mining industry in Canada has been dramatically affected by the changes that have occurred in the world mineral market place. World economic restructuring in the post ""oil shock"" period of the mid-1970s, greatly increased competition from suppliers in the developing countries, and commodity price and currency pressures have all combined to severely test Canadian competitiveness. In the new mining world, the rate of growth of demand for metals has declined due to product downsizing, materials substitution, and a relatively slower growth of over-all world economic activity.The interplay of market and political factors is complex. Canadian metal mining companies must compete in world markets against low-cost producers in developing nations whose priorities often appear to be centred on maximizing foreign exchange earnings to foster development goals and debt repayment. Many of these countries have high levels of government intervention in their mining industries. The result is a greatly in-creased number of suppliers all vying for a share of a world demand growing at a relatively slower rate than in the past. To be able to compete under these circumstances, Canadian companies have had to undertake 'survival mode' measures and look to new ways of doing things. In order to identify the effects that the recent market and economic trends have had on the Canadian metal mining industry, a study was undertaken by Canada Employment and Immigration to assess these changes and their implications for the metal mining workforce.The Canadian Occupational Projection System (COPS)—Sector Study Group with the cooperation of the Mining Association of Canada, undertook a human resource survey to gather current employment and occupation information. This formed an important part of the Canadian Occupational Projection System Metal Mining Sector Study. This article addresses the with survey results, a C.E.I.C. worker mobility study, and trends and issues that are changing the mix of jobs and the way they are being done.Figure 1 shows metal mining employment for the period from 1974 to 1984. It provides a clear picture of the employment swings that the industry has experienced especially during the recession period of 1981 to 1983. From 1981 to 1983, employment dropped by 14 000, from 68 000 to 54 764, and then dropped to its lowest point in 1984 of 52 783. We feel that employment in the medium term will be flat with growth in gold mines being largely offset by continued workforce rationalizing in other sectors.Perhaps the key point is that equivalent levels of output have been achieved in the recent period (1981-1984) with a workforce that is 25% smaller than it was in 1974. This also raises the questions which the COPS/MAC survey and COPS mobility study sought to clarify, namely, what jobs have been cut and where have these people gone? Equally important are the questions of occupational skill level changes, and what types of jobs are declining and which ones are becoming increasingly important, as economic and technological changes have altered the mining work place."

Jan 1, 1987

By G. S. Crawford

Forecasts prepared by the B.C. Research Council for the National Harbours Board suggest that mineral shipments through B.C. Lower Mainland port facilities will increase more than four-fold, from 6 to about 25 million tons, during the decade 1965 to 1975. The longer term outlook is for a six-fold increase to about 35 million tons by 1985. In 1967, minerais accounted for more than one-third of the total deep-sea traffic tonnage, nearly as much as grain. By 1975, the minerals' share will be about half the total. The principal items are exports of potash from Saskatchewan, and of coal and sulphur from Alberta and British Columbia. Additional exports include copper and other mineral concentrates and propane. Imports are chiefly salt and phosphate rock. Coastal traffic in such items as cement, sand and grave!, and limestone totalled 3.3 mil-lion tons in 1967. They will continue to be of major importance, but do not have the spectacular growth potential of the deep-sea traffic.

Jan 1, 1968

By William H. Bassett

RECENTLY it has become the custom of retiring presidents to talk of the relations of the Institute to its membership and its constituency- and it seems a good precedent to follow. Past-president Smith reviewed our relations to materials and to society in general. Mr. Bradley spoke of the value and use of our publications and of our educational duties. My message will be in regard to the coordination of our various groups of member interests and of service to industry. This Institute has, within its organization, four divisions and fourteen technical committees--each interested in a separate put very definite subject, and each covering a phase of mining engineering interest. These vary from geology and the geophysical methods of prospecting, to the physics of the structure of metals, truly "from the mine to the consumer"-from the preparation for mining to the final use of that which has been mined.

Jan 1, 1931

By Dan A. Brown

The New Mississippi River Bridge (MRB) employed conventional design-bid-build procurement, but the bidding process included the opportunity for pre-qualified bidders to develop and propose confidential Alternative Technical Concepts (ATC?s) for evaluation and approval in advance of bidding. The ATC process provides a mechanism for value-engineering prior to bid, with incentives and opportunities for both the owner and the bidding contractor. The contract described in this paper is for the river bridge composed of a cable-stayed crossing with two pylons and the anchor piers on each side of the river. The Massman-Traylor-Alberici (MTA) team developed a re-designed foundation system for the main pylon and anchor foundations which utilizes their equipment and experience along with field load test measurements to optimize the foundations. The paper describes the experience with the use of the pre-bid ATC process on the project from the perspective of the bidder, and outlines some of the benefits and limitations of this concept with respect to foundation design and construction. Some keys for success are identified and impediments to the effective implementation of the process are described.

Jan 1, 2011

By Peter N. Calder, J. L. Workman

There are many opportunities for computers to assist in dragline mine planning. Three important areas particularly lend themselves to computer assisted study. These are overall mine design and planning, the computation and display of range diagrams and the calculation of production and production variability. The computation of range diagrams is of particular interest because of the importance of matching the dragline and site geometries. This paper examines the uses of range diagrams in dragline mining and illustrates the application of computer techniques to the computation using one such program as an example. The use of computer generated range diagrams for machine selection, pit design and in parameter analysis is discussed. Directions for further development are also provided. There is a great deal that can be done to additionally enhance the ability to provide accurate designs for the dragline operation. One area that needs special attention is the dumping of overburden around access ramps into the pit. This situation is one of the most difficult dumping sequences and affects machine selection and pit operation. It is also suggested that programs that simulate the production schedule of the drag-line would be useful. It is concluded that large overall mine planning programs are very important in dragline mining. However, smaller programs designed for a specific, task are also important tools in many cases. These are easy to learn and use, well adapted to the PC environment and provide useful information, both for design and for daily planning.

Jan 1, 1989

Magnetic anomalies in the Southern Coalfields have been subdivided into two characteristic types. Each type is attributed to a separate cause, one being basement structure, and the other near-surface igneous intrusions.Detailed geological mapping of the area and the ability to sample throughout the coalmines greatly assisted in this subdivision.The Triassic sequence contributes no magnetic effect of its own except to diminish the effect of sources within the underlying formations by raising the level of observation.Detecting the presence of igneous intrusions ahead of colliery working faces by magnetic observations within the coal mines may be of value in preventing accidents caused by gas outbursts and in planning the workings so as to avoid loss of production time.

Jan 1, 1967

By Ivan Carrasco, Benjamin Cebrian

Mining companies have traditionally organized their structure around a scheme easy to manage: Mining Department and Mill Department. In a challenging landscape for mining, with decreasing grades, increasing rock hardness and more expensive energy, this way to organize departments has resulted in internal disputes and often contradictory targets between both mine and mill. These compete for individual, separated budgets whose Key Performance Indexes often damage each other’s output. The results are increased total production costs and reduction of profits. Some companies have completed the first step in eliminating these inefficiencies by creating Fragmentation Engineers and Fragmentation Superintendents. With all the knowledge available on the overall fragmentation process and costs, in this document an overhaul of the traditional management structure is proposed. Is a step further Mine-to-mill and mine-to-leach programs. Since comminution is the most expensive step of the mineral exploitation, it should be taken as a whole, not divided into competing departments. Thus, mining departments should be re-grouped into: transportation, fragmentation and flotation.

Jan 1, 2014