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By L. Donovan Clark

The term "powder factor" is almost universally accepted as the measure of the efficiency of a blasting program. It represents the economics of blasting since it designates quantity of explosive (thereby providing quality control in rock fragmentation) in terms of the associated volume broken. It is the wide use of this concept that explains the interest shown in an approach to rock blasting preferred by A. W. and Z. W. Daw* in a treatise on 3 blasting (1) substantiating its use in the form, Q = CVW3 for single shot hole, where Q = quantity of explosive lb Cv = blasting coefficient W3 = unit volume of rock It is obvious that the term Cv could also be called the apparent powder factor should the equation be written in the form, Cv = Q/W3 (lb per cubic unit). However, while the approach was ingenious** and the practical applications straightforward, their original, rather limited experimental work, along with certain assumptions, was questioned.

Jan 1, 1970

By H. R. Butler, J. F. Church, A. T. MacGibbon

Introduction Inco is the major North American nickel producer. Initially based in Sudbury, Ontario, its past exploration activity was directed toward finding new nickel deposits. New nickel sulfide discoveries outside Sudbury have included Thompson, Manitoba; Shebandowan, Ontario; and Widgiemooltha in Western Australia as well as a host of nickel laterite deposits. The company is currently diversifying into other commodities, including gold. Inco's exploration department participated in uranium discoveries in Saskatchewan and chromite discoveries at Tiebaghi in New Caledonia. In addition, it found new gold deposits at Lupin, Northwest Territories; Crixas, Brazil; Hoyle Township, Ontario; and Casa Berardi in Quebec. Crixas and Casa Berardi are currently being evaluated by underground exploration. Figure 1 shows some Canadian Shield gold locations where Inco is or was an active participant. Base metal developments Base metal exploration in shield areas has been greatly eased by applying scientific studies. Archean nickel sulfide deposits have been found using komatiitic-flow models (Fardon, 1971). Volcanogenic massive sulfide model has been applied to copper-zinc deposits (Sangster and Scott, 1976). Such deposits were subsequently seen developing on the sea floor through black smokers (Spiess, MacDonald, and Atwater, 1980). Sedimentary processes were recognized early as important in ore formation, particularly in the southern hemisphere (King, 1976). And many ore deposits are now regarded as a simple part of the geological column (Stanton, 1960 and 1972). Petrographic work on alteration patterns in and around ore bodies was used to develop standard porphyry copper models (Lowell and Guilbert, 1970). Epithermal models for precious metals followed. Stratigraphic zonation patterns have been formulated for base metal deposits, including keel facies, ore facies, and cap or distal facies. Gold developments The work on base metal deposits naturally spilled over into precious metal exploration when the gold price was allowed to float on world money markets. Early work on elements associated with gold deposits, especially arsenic, tellurium, selenium, and mercury, pioneered more detailed geochemical work (Bagby and Berger, 1985; and Groves, Ho, and Houstoun, 1984). Geochemical patterns have been recognized around microfine gold deposits. And the study of gold precipitation patterns in modern geothermal systems has helped understand gold deposition. In the late 1960s and early 1970s, it was noticed that numerous Archean banded iron formations contained anomalous gold values. From this and other observations, the syngenetic exhalite gold model has developed. Gold deposits also occur along shears in some plutons such as the Belmoral mine in Quebec. This indicates the importance of epigenetic processes in ore formation. Shield ore settings Initial studies recognized that the major gold camps in the Canadian Shield were mostly in greenstone belts and found along "breaks," especially zones of faulting and sedimentation. Gill (1948) wrote, "Only recently, as a result of detailed mapping, has the importance of major schist zones such as the Larder Lake, Cadillac, Porcupine Creek, and Destor Breaks been recognized. These zones of persistent adjustment mark broad belts favorable for ore occurrence." The importance of shearing in ore location and regional greenstone stratigraphic position close to late sedimentary packages was clearly understood. And structural models have been further developed for some Canadian ore deposits (Hubert, Trudel, and Gelinas, 1984). In the Beardmore-Geraldton camp of northwest Ontario, the importance was soon recognized of fold noses in banded iron formation, as localizers for gold ore. This importance had also been recognized in Western Australia,

Jan 2, 1987

By B. Alegria

The depressing effects of different inorganic chemicals on the flotation of pyrite have been investigated in this study. The results of the flotation tests indicate that pyrite can be depressed by oxidizing as well as reducing agents under controlled conditions of pH and reagent dosage. Oxidizing reagents such as potassium chromate and potassium dichromate were found to cause complete depression of pyrite in the acidic pH range. These effects are similar to those obtained in the pyrite-cyanide system. A less stable oxidant, potassium permanganate, inhibited the flotation of pyrite at a concentration as low as 0.1 mol/L at all pH values, Addition of reducing chemicals such as ferrous chloride or manganous sulphate to the flotation of pyrite were found to produce depressing effects depending on the additive concentration and pH of the solution.

Jan 1, 1982

By Y. Lahaye, O. Martinsson, B. I. Palsson

"Four main and three minor rare-earth-element (REE)-bearing minerals were identified and quantified in the Kiirunavaara apatite iron ore tailings using optical microscopy, an electron probe microanalyzer (EPMA) and a mineral liberation analyzer, and their chemical compositions were analyzed by the EPMA and laser ablation inductively coupled plasmamass spectrometry. REEs are shown to be contained in the minerals apatite, monazite, allanite, titanite, zircon, thorite and synchysite. In zircon, thorite and synchysite, they occurred in only trace amounts and contributed limited amounts to the total REE budget, and these are consequently of minor importance. Monazite occurred as inclusions in apatite and as free particles, 90 percent liberated. Allanite occurred to some degree in mixed grains with magnetite but also as free particles. Monazite mainly reported to the apatite concentrate, while allanite and titanite largely went to the tailings, the latter preferably to those fractions smaller than 38 µm. The amount of titanite in the finest tailings fraction was 2.3 weight percent, containing close to 1 percent REEs, with heavy rare earth elements (HREEs) making up 28 percent of the total REEs. However, a texturally distinct group of titanite grains showed an HREE/REE ratio of up to 67 percent. Furthermore, titanum dioxide analyses indicate that titanite is preferentially released into the tailings from the secondary magnetic separation step in the concentrator. Our data therefore suggest that titanite, occasionally enriched in HREEs, can be extracted from the processing stream and might thus be considered a new source for REEs at Kiirunavaara and similar deposits.IntroductionDeposits of apatite iron ores are the major source for iron in the European Union and are exploited by Luossavaara-Kiirunavaara AB (LKAB) in several mines in the Kiruna-Malmberget area in northern Sweden. Kiirunavaara is the largest of the apatite iron orebodies in Sweden, comprising more than 2 Gt of iron ore with 60 to 68 percent iron (Fe). At the end of 2015, the total accumulated production of crude ore from openpit and underground mining since the start of mining was 1,566 Mt, with ore reserves of 644 Mt grading 46.3 percent Fe (LKAB, 2016). The deposit defines a steeply dipping tabular body, approximately 6 km long and up to 180 m thick, extending at least 1,500 m below the surface. It is situated in the middle part of the Palaeoproterozoic Kiirunavaara Group of volcanic rocks and follows the contact between a thick pile of trachyandesitic lava and overlying pyroclastics (Martinsson, 2004)."

Jan 1, 2017

By Harry D. Lewis

Gilsonite is a lustrous black material that can be easily crushed into a chocolate-colored powder. It is a solid but relatively soft, lightweight hydrocarbon that visually resembles the volcanic glass obsidian. It was once thought to be a type of coal, but because it is thermoplastic it melts rather than bums. Gilsonite is found in commercial quantities only in the Uinta Basin of eastern Utah and western Colorado, where it forms vertical, nearly parallel veins of varying depth, width, and length. Gilsonite from different veins has different properties, most notably variations in softening point and solubility. These differences result in its use in a variety of industrial applications. Gilsonite's earliest commercial uses were in varnishes, buggy paints, and beer vat linings. Eventually it came to be used in more than 160 products ranging from inks to explosives. It is exported from the United States to most industrialized countries throughout the world. Today, due to competition from synthetics and other hydrocarbon products, its use has narrowed to several specific industries. Although sold mostly as a commodity, current research is focused on applications for gilsonite as a value added product. Historical Overview The discovery of gold in California and the dawn of the mining era in Nevada, Colorado, and Utah around 1850 brought a wave of prospectors to the western United States. One of those pioneers, Samuel H. Gilson, is generally credited with a major role in the discovery of gilsonite. The material now known as gilsonite was discovered several times from the late 1860s through the mid-1880s. It was William P. Blake who, after receiving samples of the material, wrote a paper in 1885 describing "a new variety of asphaltum from the Uinta Mountains." He termed the material uintaite. Although Sam Gilson was not the first to discover the mineral, he was an-inventor who used gilsonite in products that he patented. It was his conviction that the substance was of great value, which caused some to refer to it as gilsonite. The term Gilsonite became the registered trademark of the American Gilsonite Co., and it continues to be in use today. When the first company was formed to mine this substance in 1886 it was named the Gilsonite Manufacturing Co. This firm acquired many gilsonite mining claims and marketed a varnish made from the material. It was the unusual properties of gilsonite varnish that attracted the attention of Adolphus Busch of the Anheuser-Busch Brewing Co. In 1889 Anheuser-Busch bought out Gilson's interests and formed the Gilson Asphaltum Co. Busch had been importing asphalt from Sicily for use in lining beer barrels and saw gilsonite as being more readily available and cheaper. Although gilsonite did not work well in this application, Busch did acquire a large number of mining claims in the Uinta Basin. In 1903 the parent firm of Gilson Asphaltum financed the building of an 85-km railroad from near Grand Junction, CO, to Dragon, UT, to haul gilsonite ore to market. Underground mining was initially centered near Dragon and then later at Bonanza, UT, as different veins were mined. The railway was abandoned in 1937 in favor of truck transportation. In 1938 Gilson Asphaltum changed its name to Barber Asphalt Co., the predecessor of Barber Oil Corp. In 1946 Barber Oil teamed with Standard Oil of California to form a partnership, American Gilsonite Co., which today has its operational headquarters at Bonanza, UT. Barber Oil investigated many new uses for gilsonite, including the making of petroleum derivatives such as gasoline. This work led to the construction of a 116-km pipeline to carry slurried gilsonite to a refinery in Colorado for the production of gasoline, fuel oil, and coke. Pipeline operations began in 1957 but stopped when the economics of competing with petroleum became unfavorable, and the refinery was sold in 1973. In 1981 Standard Oil (later Chevron) became the sole owner of American Gilsonite and remained so until 1991, when it sold its interest to Stratford Enterprises Co. of Tulsa, OK. The companies have since been merged and now operate under the name American Gilsonite Co. with headquarters in Salt Lake City, UT. American Gilsonite continues to be the world's largest miner and supplier of the mineral. The American Asphalt Association was formed in 1902 by former stockholders in Gilson Asphaltum. This company mined various gilsonite claims until it was dissolved in 1953 and its properties were sold to American Gilsonite and Gordon S. Ziegler and Associates. The Utah Gilsonite Co. was established in 1920 and mined several claims until 1952, when its holdings were sold to Gordon Ziegler. Several other gilsonite mining ventures have been pursued in Utah, although they were significantly smaller in scale than those described above. There are currently three companies which mine gilsonite resin in Utah. They are American Gilsonite Co., Ziegler Chemical & Mineral Corp., and Lexco.

Jan 1, 1994

By Justin Jensen, Luis Moya, Jose Carlos Durazo, William Szolga, Tyler McCallum, Tim Doubleday

Sulfuric acid mist is an undesired by-product of the copper electrowinning process, caused by oxygen evolution at the anode which entrains droplets of the acidic copper electrolyte solution. As the oxygen moves to the surface of the cell, these droplets become aerosolized resulting in acid mist. The addition of chemical anti-misting agents to the copper electrolyte is a common mitigation technique. This paper details Syensqo’s laboratory development of a new environmentally friendly acid mist suppressant, ACORGA® EW98. The product exhibits excellent acid mist suppression and it is fully compatible with the adjacent solvent extraction process. Lab and pilot test results are reviewed ahead of future planned industrial trial testing.

Feb 1, 2025

By Bryan Ulrich

Knight Piésold and Co. hosted its annual roundtable discussion on March 17, 2011 at the Stockman Hotel and Casino in Elko, NV. The theme for Roundtable 2011 was, ?High density tailings, paste, and filtered tailings,? although the topic may well have been subtitled, ?Don?t prematurely rule out any technologies before they are given their day in court.? Bryan Ulrich, Knight Piésold?s local representative, as well as Tom Kerr from Knight Piésold?s office in Denver, CO, were on hand to help facilitate the discussion. Ulrich and Kerr are senior vice president and president of Knight Piésold?s U.S. practice, respectively. The event played host to more than 30 attendees from several western states. Attendees included personnel from a dozen mining properties and various corporate offices. There were also attendees from manufacturing and specialist consulting firms who have been providing services to various high-density tailings, paste and filtered tailings operations worldwide. It may be noted that the term ?filtered tailings? is used in this discussion. Alternative terms, such as ?dry stack? or ?dewatered tailings,? should be avoided whenever possible, as such terms tend to give a false sense about the nature of the material since these materials typically still retain a significant amount of moisture.

Jan 1, 2011

By J. A. Marts, R. C. Gilmore, Jr. Bogin, S. A. Saki, J. F. Brune, J. W. Grubb

"Colorado School of MinesResearchers at Colorado School of Mines (CSM) have developed computational fluid dynamic (CFD) models to study gas distributions and explosion and fire hazards in longwall gobs. In underground coal mines, methane continuously emitted from surrounding strata mixes with air from active mine workings and may form explosive gas zones (EGZs). Some western United States coal mines are also prone to spontaneous combustion (spon com). Insight into oxygen concentrations within the gob is crucial for assessing spon com hazards and mitigation strategies. Nitrogen injection used in conjunction with progressive gob sealing can reduce EGZs and spon com hazards by forming a dynamic seal that separates the methane in the gob from the air that ingresses from the face. This paper describes CFD modeling simulations studying the formation of such dynamic seals by optimizing the nitrogen injection locations. The impact of nitrogen on oxygen ingress and formation of EGZs is discussed. Optimum nitrogen injection quantities and injection locations were determined. Dynamic seal formation is most effective if the headgate nitrogen injection locations are split between the first crosscut inby the face and a second location about 300 m (1,000 ft) further inby. INTRODUCTION Underground longwall coal mine ventilation systems are designed to dilute hazardous gases and to provide breathable air to miners working in the area. Methane gas is liberated as the mining process extracts the coal and disturbs the surrounding strata. Methane mixes with the ventilation air and often produces explosive gas zones (EGZs) within longwall gobs (Brune 2013). Past CFD modeling research of underground coal mine ventilation systems has shown the effects of face air quantity on EGZs (Worrall 2012) and nitrogen injection to control spon com (Balusu et al. 2005; Ren et al. 2012; Ren et al. 2011; Smith and Yuan, 2008; Yuan and Smith, 2014). Other modeling approaches include network ventilation models of oxygen ingress (Dziurzynski and Wasilewski, 2012), and coupled Linear Network CFD algorithms (Wedding 2014). In a project sponsored by the National Institute for Occupational Safety and Health (NIOSH), CSM researchers are using Fluent®, a CFD software package by ANSYS, Inc., to model gas compositions and flows in underground longwall gobs. Figure 1 shows a progressively sealed gob with a U-type ventilation system in a three entry development. As the longwall advances, seals are constructed along the headgate in the crosscuts between the center entry and the gob. Additional gob isolation seals are built to block off the headgate entries inby the face. Nitrogen is injected through the seals in the first two crosscuts on the headgate side and at the first crosscut inby the face on the tailgate side, as shown in Figure 1."

Jan 1, 2015

By D. Scott Scovira, Karl Dufresne

Blasting in geothermally high temperature ground and/or extremely reactive ground is an increasing common challenge for surface and underground mines. Many current PETN based non-electric and electronic detonators have manufacturer published in-hole temperature limits ranging from 55°C to 65°C (131°F to 150°F). When confronting blasthole temperatures above the manufacturer published limits, operations may request site-specific guidance and qualification for use. The advised safe loading window for in-hole PETN based detonators is often too short to be practicable for production blasting. To overcome limitations of PETN based initiation systems, surface mines with high temperature ground and/or reactive ground are known to load blastholes with a qualified high temperature bulk emulsion that are top primed with a cartridge of temperature qualified detonator sensitive emulsion plus an RDX detonating cord downline. As there is no in-hole delay detonator in this system, blasthole timing is accomplished with surface delays. Although this system is safe, top priming and surface delaying does influence floor quality and top size fragmentation, and safe loading windows times reduce blast block size and increase blasting frequency. A mining company with a site characterized by geothermally high temperature ground plus highly reactive ground employed a blasting system like the one described above. The site desires to improve blasting performance by moving to an in-hole delay initiation system that can withstand the site ground conditions. At the request of the mining house, DynaEnergetics developed an electronic initiation system for application in geothermally high temperature ground and/or extremely reactive ground conditions. The DynaEnergetics IGNEO high temperature electronic initiation system is rated for in-hole use in ground up to 150°C (302°F) for 48 hours. The detonator consists of a high strength detonator with an HMX base charge and thermally resistant downline. To make up a primer, the detonator is inserted into a booster charge assembly that is fitted with a small HMX shape charge. This high energy primer is designed to be compatible and reliable for firing bulk emulsions, including those with high percentages of urea inhibition to combat reactive ground. Up to 1000 detonators may be programmed in 1 ms increments up to 1500 ms. The system is controlled by a digital firing panel that can be used with either a wired or wireless trigger. The system enables high temperature and/or reactive ground sites to utilize in-hole delay initiation and realize the associated performance benefits.

Feb 1, 2024

By M. J. Gilbey

London Underground is the oldest and one of the deepest Metros in the world. The temperature of the Underground has been increasing over the last 100 years, mainly as a consequence of increases in train service. Further increases in train service are planned in the coming years to meet the predicted growth in passenger demand. Unabated, the additional service will increase temperatures on the Underground. London Underground Limited (LUL) has therefore set up the Cooling the Tube Programme (CTP) to tackle the issues of thermal conditions on the Underground. Some of LUL?s studies and cooling methods have borrowed experience and techniques from the mining industry; some of methods used or proposed may in turn be of interest to the mining community. This paper presents a background into the sources of heat on the Underground network, the manner in which the heat is presently dissipated, the analysis of future temperatures and criterion and a number of means and methods being used or proposed to cool the network in an environmentally sensitive manner.

Jan 1, 2009

By M. Deul

For the first half of the 21st Century the USA will rely on the same mix of fuels as for the past 50 years: Petroleum will cost more and availability will decline as developing nations modernize. Increased use of natural gas for electric power generation will result in severe stress on gas supply. Coal will be the fuel of last resort. More than half the petroleum used is imported, about the same amount as used for transportation. Only coal can provide relief by fueling railroads through electrification while encouraging ‘piggy-back’ trailer haulage, co-generation for manufacturing and expanded passenger service.

Jan 1, 2002

By J. H. Gasper

A cost analysis for two alternative contour mining methods is performed to compare their results. The methods evaluated are: 1) Front-End Loader/Truck Haulback and 2) Scraper Haulback. Before performing these analyses, output requirements and equipment needs are found based on integrating geometric limitations with material properties. The final geometric design establishes limits on clearances, congestion problems and grades (with associated running surface materials). All calculations are kept practical, with assumptions clearly stated. The cost analysis is a unique, easily utilized compilation of several different approaches incorporating cost engineering principles. The strengths of each are welded into a cohesive entity once again aimed at practical application. The results are presented in tabular form.

Jan 1, 1992

By D. Wenstrup, K. Perry, J. Hatfield, P. Sainato, B. Lusk

Concrete-infused cloth is used in several civil and mining surface applications whose circumstances are similar to some of those in underground mining. A feature of this material is that it cannot be overhydrated. In underground conditions, however, the excess supply of water to the cloth for hydration could lead to muddy and potentially unsafe working conditions, as well as resource wastage by supplying more water to the construction site than is needed. The objective of this study is to verify the water-to-cloth ratio and study the effect of hydration level on the strength of the Concrete Cloth product. We found that the strength increases with increased hydration up to a 1:2 water-to-cloth ratio by weight, after which the strength holds steady regardless of additional hydration. This confirms the 1:2 water-tocloth ratio by weight for hydration and confirms that strength is retained even if the cloth is excessively hydrated.

Jan 1, 2014

By George E. Valadão, Iván A. Reyes, Mizraim U. Flores, Armando C. Araujo, Rubén H. Olcay

Dewatering tailings to higher grades than paste produces a stable deposit that typically does not require retention dams and is called a “dry stack.” A proposal of different dewatering techniques applied in the fine tailings produced after final desliming phase, obtained from the treating of phosphatic ores, is the main objective of this work. The dewatering techniques evaluated were column thickener, deep cone classifier, and hyperbaric filtration. Calcite and dolomite were the main mineral contained in the phosphate tailings and these have a very fine granulometry; the tailings presented different behaviours related to the dewatering technique applied. The test column thickener and deep cone classifier with the best operational parameters found to obtain a maximum percentage of solids in mass were ~ 71% and ~ 67%, with values of yield stress ~ 200 Pa and ~ 100 Pa, respectively. In the hyperbaric filtration, a cake with ~ 10% moisture was obtained. This indicates that the transportation conditions are not the same. The overflow turbidity levels obtained from column thickener and deep cone classifier test did not exceed the value 100 NTU, whilst for the filtrate of the hyperbaric filter obtained values ~ 800 NTU. It was possible to preliminary estimate the recovery direct of water, considering each dewatering technique for final disposal of the tailings. The best dewatering techniques obtained were in the following order for the disposal in phosphate fine tailings dams; the hyperbaric filter showed an excellent dewatering capacity with productions rates around 160 kg h− 1 m− 2 for moisture cake of 10%, followed by the column thickener and deep cone classifier with paste ~ 71% of solids (W/W) and high-density slurry ~ 67% of solids (W/W), respectively.

Dec 23, 2023

An important problem in mine operations is the classification of material as waste, low-grade stockpile, and ore. This classification must often be made with blasthole data that are widely spaced and that have sampling errors. Geo-statistical simulation techniques combined with basic economic principles allows a procedure for classification that maximizes expected profit. Geostatistical simulation methods (Gaussian, indicator, or annealing-based) allow the integration of hard and soft data in the creation of alternative, equally-probable, realizations of the mineral grade(s). At each location, for each realization, we calculate the "profit" if the block were to be classified as ore or waste The optimal classification is the one that maximizes expected profit (a Maximum Profit Se-lection (MPS) procedure). We discuss the theoretical justification of the method and implementation details. The use of blasthole data from different types of mineral deposits, that is, different levels of continuity, is considered. We also show the efficacy of the procedure with different levels of sampling error. The increased revenue due to the MPS procedure and improved sampling is shown. We show the geostatistical simulation procedure and the uncertainty in block grades that result from incomplete and imperfect sampling. The optimal classification is presented. Optimal block classifications are transferred to realizable dig-limits by hand-drawing polygonal boundaries. We compare the results of the proposed method to classification based on kriging. Limitations and areas of future work are identified.

Jan 1, 1999

By C. Hendricks

This paper is based upon field studies conducted in a western Canadian open pit coal mine. This work has involved the adaptation of microprocessor-based instrumentation to monitor various operating parameters on-board blasthole drills and mining shovels. A review of instrumentation and monitoring methodology will first be presented. Based upon experience from field-based studies, the paper will subsequently focus on the application of monitoring technology within the framework of an integrated Equipment Monitoring System. Such a system will permit the real-time performance evaluation of key equipment involved in surface mille production.

Jan 1, 1991

By S. A. Sanderson

The last two decades have witnessed the resurgence in popularity of a century old tool for shaping laws and public policy – the ballot initiative. In recent years, anti-mining special interests have used the initiative process to secure voter approval of measures to ban modern surface mining for gold and silver. In November 1998, voters in Montana approved such a measure1 – the effects of which have been devastating to the mining industry in that state. In November 1999, anti-mining groups sought to place a nearly identical provision on the general election ballot in Colorado. They did not succeed, but the battle over mining’s future continues in the most important forum of all – the court of public opinion. The Colorado measure failed, in large part, because its proponents failed to convey a positive environmental theme. The mining industry also exercised early-on the rights available under state law for administrative and judicial review of the initiative, instead of relying upon the limited relief that would have been available had it waited until after the secretary of state approved the measure for the November election ballot. This article will summarize the ballot initiative process in Colorado and the proceedings that took place over Initiative No. 215.

Jan 1, 2001

By Nicolin Govender, Pramod Kumar, Raj Rajamani

Mill power models have been used in a variety of ways in industrial practice since power directly equates to throughput and fineness of ground product. We first start with Hogg-Fuerstenau Power Model and show how this model successfully predicted the power draw of many grinding mills in several mining operations. Then, we show how this model was on the verge of being able to predict the influence of lifter design on power draw. Next, we describe the discrete element model and how it overcame the issues faced by the previous power model. Using a DEM software known as Millsoft, we show the influence of lifter design geometry on power draw and analyze the power draw of rubber lifters versus the steel lifters via several case studies. As years passed, the two-dimensional discrete element model imbedded in Millsoft is superseded by three-dimensional discrete element method. Due to the gigantic computational power of graphic processing units, new computational codes that can do the tumbling motion along the entire length of the mill has come about. Here, we show the predictive capability of Blaze-DEM for ball and SAG mills.

By ANDREW HOBERT, Maoming Fan

Low-cost and environment-friendly green froth flotation modifiers of plant origin, such as guar gum, carboxymethyl cellulose (CMC), and starch, have been used in flotation of some sulfide and non-sulfide minerals. Certain green modifiers may be used as dispersants, flocculants, depressants, or activators. The functions of green modifiers in froth flotation highly depend on their molecular composition, flotation slurry chemistry, hydrodynamic conditions, etc. This paper will discuss the fundamentals, current applications, and potential new applications of guar gum, CMC, and corn starch in valuable minerals (phosphate, potash, and iron ores) and the unwanted gangue minerals (silica and clay minerals) flotation. In this study, improved flotation performance was achieved using some green modifiers in flotation columns with the more plug-flow environments than in conventional flotation cells approaching perfectly mixed conditions. This is because the hydrodynamic cavitation-generated ultrafine bubbles could help bridge ultrafine particles to form aggregates, promote the formation of flocs, and increase the stability of flocs.

Jan 6, 2022

Collaboration between education providers is the key to long-term sustainability and improved quality in mining education. The mining industry is now, more than ever, an industry doing business on a global basis. Staff are recruited by global mining companies in many different countries and can find themselves deployed anywhere in the world. The mining engineer of tomorrow must be willing to take on this international challenge, and must be educated to a level where he or she has a comprehensive grounding in technical aspects of mining engineering, but also a well-founded appreciation of management, social, environmental and cultural issues that may be encountered around the world. In order to deliver such an education, academic providers must collaborate at both a national and international level. This paper provides an overview of progress that has been made in Australia through the national joint venture ? Min¬ing Education Australia (MEA). Supported by the mining industry in Australia, through the Minerals Council of Australia (MCA), MEA has been operational since 2007 and is seeing the development of a range of innovative courses and delivery methods, together with a high level of staff cooperation across the country. MEA has also commenced some international teaching initiatives that are seen as a catalyst for a far greater degree of international collaboration in the future. Such activity is not only to the benefit of the students who are taught by experts from around the world, but it also ensures that individual univer¬sity programs remain viable in terms of staffing numbers and financial performance. The paper also presents some statistics on recent upward trends in mining engineering student numbers from around the world, in response to the global shortage of mining engineers.

Jan 2, 2010