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By Ed Sullivan

"Australia is one of the richest continents when it comes to mineral extraction, ranging from exotic projects like the Olympic Dam — a copper, silver and uranium mine believed to have the world’s largest uranium resource — to the extensive iron ore, nickel, coal and gemstone formations that provide many of the country’s most rewarding exports.Among the challenges to succeed in this industry is the ability to provide efficient “pitto- port” infrastructure performance, which essentially means ensuring that minerals move seamlessly from the point of extraction to the facilities that can then move them to international market destinations.To provide such efficiencies, avoid human error and facilitate automated mining functions, producers are increasingly turning to fiber optic cable suppliers for “end-to-end” communications and control solutions. Many such solutions include ruggedized cable and connectors that ensure the survival of fiber-based DCS/PLC automation/ control architectures for various types of mining operations, even in the harshest environments.Integrating the solutionAs industrial Ethernet and fiber optic cable emerges as the medium of choice in many industrial arenas, communication and control integration using the most appropriate products for a specific application is increasingly important.“This whole ‘pit-to-port’ performance concept is focused on control and process automation,” says Boyd McDonald, Founder and Managing Director at Datalek Systems & Electrical, Rockhampton Area, Australia. “It also means bringing reliability to networks and providing the needed bandwidth. An appropriate plug-and-play solution is also important because it takes human error out of the equation.”Datalek Systems & Electrical, is responsible for the design, installation and maintenance of numerous fiber optic communications systems including those that involve automation, security, access control an CCTV systems for open-pit and underground mining operations as well as LNG and coal seam gas facilities."

Jan 1, 2015

By Yang Zhao, Wanping Wang, Siqing Liu, Shuming Wen

"In China, most reserves of rich iron ores have now been depleted and sustainable development of low-grade iron ores has become a critical discussion topic in the mining industry today. The aim of this study was to evaluate the applicability of beneficiating a low-grade, hematite-magnetite ore (assaying 18.64% Fe) for subsequent utilization. In this study, process mineralogy and beneficiation of the ore were carried out in the laboratory. First, mineralogical investigation shows that the main metal minerals are hematite, magnetite and a little octahedrite that cannot be used at present, and the main gangue minerals include albite, quartz and ankerite. Based on the above, a combined process of magnetic separation and gravity concentration has been developed by using laboratory low- and high- intensity magnetic separators and a slimes shaking table, respectively. Factors affecting these separation methods are discussed, including process mineralogy on the tailings of the high-intensity separator, where the iron minerals were found to be finely disseminated in the gangue as inclusions. By applying a two-stage grinding step and a magnetic separation stage together with gravity concentration, a marketable iron concentrate assaying 60.79% Fe at a recovery of 60.23% can be obtained, when the feed assays 18.75%Fe, which provides some useful information for the sustainable use of low-grade iron ore.IntroductionIron is the world’s most commonly used metal. Steel, of which iron ore is the key ingredient, represents almost 95% of all metal used per year, primarily in structural engineering applications and for maritime purposes, automobiles and general industrial applications. By the end of 2009, the iron and steel production in China ranked the first in the world, and reached 0.567 and 0.537 billion tons, respectively. The domestic supply of iron ore was 0.88 billion tons and about 0.628 billion tons of iron ore were imported in 2009."

Jan 1, 2015

By Richard E. Hucko

The Coal Preparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three coals--an Upper Freeport bed coal, a Lower Kittanning bed coal, and a Pittsburgh bed coal--to establish grade- recovery relationships characteristic of both processes. Representative portions of each coal sample were crushed to two top sizes--nominal minus 35 mesh (0.5 mm) and nominal minus 100 mesh (0.149 mm)--and subjected to conventional froth flotation. The froth product was then beneficiated by coal-pyrite flotation or HCMS to provide a direct technical comparison of the two processes. At minus 35 mesh (0.5 mm), the size normally employed for coal flotation, both coal-pyrite flotation and HGMS effectively separated pyrite from coal, and the performance of the two processes was essentially the same. At a size of minus 100 mesh (0.149 mm) , however, the performance of HGMS exceeded that of coal- pyrite flotation. The separations effected by HGMS were more efficient at minus 100 mesh (0.149 mm) than at minus 35 mesh (0.5 mm). On the other hand, it was concluded that either the effectiveness of coal-pyrite flotation decreases with diminishing top size, or the process has not been optimized to treat material finer than 35 mesh (0.5 mm).

Jan 1, 1981

By Miguel Reyes, Chenming Zhou, MATTHEW GIRMAN

This paper is aimed at helping the mining industry to better understand the challenges posed by electromagnetic interference (EMI) and to promote electromagnetic compatibility (EMC) in underground coal mines. The paper begins with a review of EMI standards in other industries, then presents some representative examples of EMI instances that have occurred in the mining industry, followed by a literature review of published EMI research in mining and, finally, a discussion on mitigation strategies and practical considerations related to EMI in mining.

This paper presents the results of an experimental study undertaken to demonstrate the feasibility of using silica sand as a grinding media in stirred ball mills for ultra-fine coal grinding. Laboratory batch as well as bench scale continuous tests indicate that the use of silica sand can reduce the energy consumption by 50% and more over its steel media counter-part. Moreover, this approach has been found to eliminate the disadvantages observed with grinding using steel media such as high replacement cost, contamination of coal through media wear, greater degree of coal oxidation due to higher slurry temperature and greater level of noise dissipation. Additionally, coal-sand attrition system reduces the manpower time required which is often spent towards cleaning and storing of steel media in inert atmosphere to avoid rust and corrosion problems.

Jan 1, 1991

By W. J. Miles

Oil based drilling fluids utilize a number of industrial mineral products to accomplish oil and gas drilling in several environments where water based drilling fluids are less effective or inappropriate. These industrial minerals include: organically modified bentonite, organically modified lignite, barite, hematite, mica, calcium chloride and other salts. A variety of organic products are also utilized in oil based drilling fluid formulations. Oil based drilling fluids are preferred in several drilling situations because: they can be used to drill through water sensitive formations; they produce holes that are very close to the drill bit gauge; they exhibit high temperature stability; they are more environmentally acceptable; they minimize producing formation damage; they provide faster drilling rates when used with new polycrystalline diamond drill bits; they minimize pipe sticking and lost rig time.

Jan 1, 1986

By Heinz Petry

In deep strip mines the job of moving overburden may be so much bigger, and more costly than the removal of coal or ore that the operation is often called dirt mining. Constant improvement in stripping machines and techniques of using them is needed to offset rising costs and to increase production in mines that are now operating, and to make it economically possible to work deeper or thinner deposits.

Jan 1, 1962

By Pradip

Bastnaesite, a rare-earth fluocarbonate, was separated from associated calcite and barite gangue minerals in the Mountain Pass, CA rare-earth ore beneficiation plant by froth flotation using fatty acids (tall oil) collector, lignin sulfonate depressant and soda ash modifier after high-temperature (steam) conditioning with reagents. Starting with a feed grade of 7.6% REO, concentrates having a grade of 65% REO can be produced at a recovery of around 80%. A detailed investigation consisting of Hallimond tube microflotation experiments, bench-scale tests with a laboratory Denver flotation cell, and predesigned plant campaigns was made to delineate the underlying surface chemistry involved in this separation and to develop an alternate reagent scheme to enhance the selectivity of separation for this ore. Our results clearly demonstrate the superiority of alkyl hydroxamates to the conventional fatty acid collectors that were being used in the plant. Our study also indicates the possibility of achieving the desired selectivity with alkyl hydroxamates even at room temperature, thus obviating the need for steam conditioning. A critical review of the literature on rare-earth mineral flotation suggests the possibility of designing a more selective reagent combination for the beneficiation of Mountain Pass rare-earth ore, using a methodology based on ab initio molecular modeling computations.

By Yuexin Han, Mu. Yufan, Yanjun Li, Peng Gao, Yongsheng Sun

"The objective of this study was to evaluate the effect of reduction temperature, reduction time and binary basicity on the size of metallic iron particles in coal-based reduction products of an oolitic iron ore. The particle size distribution behavior (i.e., cumulative passing percentage and mean size of metallic iron particles) during reduction was investigated in detail. Results showed that the particle size distribution of metallic iron particles was strongly influenced by reduction temperature, reduction time and binary basicity. The cumulative passing percentage and mean size significantly increased with reduction temperature and time in the entire range of the experiments. All curves of cumulative passing percentage versus particle size under different conditions demonstrated a similar trend (continuous increase). The size distribution parameters and mean size slightly increased with increasing binary basicity and significantly decreased when the binary basicity exceeded 1.0. The size of metallic iron particles could be controlled by adjusting the reduction conditions during coal-based reduction.IntroductionThe increasing demand for iron ore coupled with diminishing high-grade iron ore reserves has resulted in the urgent need for innovative technologies in order to use refractory iron ores. Oolitic iron ore is a typical refractory iron ore with tremendous abundance globally. Based on published literature, oolitic iron ore reserves are approximately 140 million tons in Europe, 10 billion tons in China and 66 million tons in Pakistan (Kazmi and Abbas, 2001; Wu et al., 2011; Yu and Qi, 2011; Sun et al., 2013a). Therefore, the efficient exploration and use of oolitic iron ore resources can play a significant role in easing the mineral resource crisis in the iron and steel industry. However, oolitic iron ore cannot be effectively upgraded by traditional beneficiation methods due to its mineralogical characteristics (e.g., low grade of iron, poor liberation of iron minerals and high phosphorus content) (Li et al., 2011b; Sun et al., 2013b).Researchers recently proposed coal-based reduction followed by magnetic separation to recover iron from refractory iron ores (especially oolitic iron ore) and a certain degree of breakthrough was achieved in both theory and practice. In this technology, iron minerals in the ore are directly reduced by coal to metallic iron, which grows into particles of different sizes. After comminution and liberation, metallic iron is concentrated by magnetic separation (Srivastava and Kawatra, 2009; Sun et al., 2013a; Li et al., 2011b; Sun et al., 2013b; Li et al., 2011c; Gao et al., 2013). Sun et al. and Gao et al. used this technology to examine the recovery of iron from oolitic and Bayan Obo iron ores, respectively (Sun et al., 2013a; Li et al., 2011b; Li et al., 2011c). Metallic iron powder with more than 90% iron content was obtained as the final product, which could be used directly in steel production."

Jan 1, 2015

By William J. Robinson

What is the cummulative rate of recovery of copper from a sulfide leach dump? This is one of the most frequently asked questions today. We, in the industry, ask it of each other when we meet; however, the technical answers may vary from "I don't know" to 'quite good" from people within the same company. Management also poses this question because it plays a vital role in our planning for future production. The answer is difficult because of the many variables between different operations such as physical construction of the dump, topography of the original site, characteristics of dump material, mineralization, water application, etc. Each has a bearing on the rate of recovery. OPERATIONAL DATA Our method of water distribution is unique in that each dump is drilled to allow physical injection of water into the dump. The in¬jection holes are drilled vertically, on 251 centers, from the surface of the dump. Normally, the holes are drilled 40' deep and cased with 4" PVC perforated pipe.. The pipe is perforated at one-foot intervals with four V diameter holes at 901 spacing on the pipe circumference. We formerly alternated shallow holes (20'-40') with deep holes (80'-l80') in an effort to cover the entire dump and hasten oxidation. The shallow hole depth varied according to the compaction thickness. The deep hole depth varied according to the height of the dump and the original ground profile, We prefer to have the deep holes end 20'-30' above the original ground level. This generally allows us to penetrate the coarse material at the bottom of the dump. We had to discontinue the deep holes_ in order to cover more dump area in a shorter period of time to meet increased production requirements.

Jan 1, 1972

By Matthew Burdick, Andrew Rule, Erica Bailey

The Second Narrows Water Supply Tunnel, Burrard Inlet Crossing project for the Greater Vancouver Water District entails deep shaft construction, subway sized pressurized face tunneling through highly variable ground conditions, installation of three permanent steel water mains and construction of elaborate valve chambers adjacent to either shaft. The paper discusses key elements of the planning and implementation of 6.69 m Ø slurry mixshield tunnel boring machine (TBM) assembly in a small diameter deep shaft including incorporation of a fully pressurized launch lock, preparations for saturation diving, surface support infrastructure and initial mining sequence.

Jun 13, 2021

By Douglas B. Silver

Study Parameters (Status as of February 1993) Time Period: 1989 -1991 151 North American Public Metal Mining Companies Fiscal not calendar year basis 85+% of Canadian and U.S. Metal Production Au, Ag, Cu, Pb, Zn, Mo, Ni, W Results are Preliminary and Research Continues Chicken Little is Alive and Well

Jan 1, 1993

By Robert W. Gordon

The art of excavating tunnels with continuous, full-face boring machines began almost 90 years ago, in the early 1880's. At this time, Colonel Beaumont designed and manufactured a seven-foot diameter tunneler for boring under the English Channel, Despite the absence of modern materials and manufacturing techniques, Beaumont's tunneler, powered by compressed air piped in from the surface, was quite successful. During its short, but impressive existence, this machine set a record of advancing in chalk 50 feet per day for 53 days - which is impressive even by today's standards. Despite the apparent success of this early tunneler, almost 80 years passed before any further significant development was accomplished in this field. Demands from the construction and mining industry and society itself have motivated the development of the modern tunneling machine. Our rapidly growing civilization needs faster, less expensive and safer means of excavating tunnels. Space age technology and materials have played a major role in making hardrock tunneling machines possible.

Jan 1, 1970

By Glenn A. Squibb

An example of market development is described. The market in rail-lake movement of coal is vital to a rail carrier because of its location. This market is threatened by nuclear and other competing fuel sources and by depressed all-rail unit train rates, The first step to develop the rail-lake transportation market consists of rate adjustments and tariff changes to force tighter scheduling of mines, railroad, port and boats, and thus reduce cost. The second step provides a surge pile at the port to eliminate most of the seasonal disadvantage of rail-lake movement and reduce car detention at the port to almost zero.

Jan 1, 1966

By W. C. Meyer

The concept of using powdered coal-in-oil-mixtures (COM) as a composite fuel to conserve oil resources and relieve import supply problems is being vigorously promoted by the Department of Energy via the sponsoring of various demonstration units (1). The idea of COM as a useful alternative fuel has been explored on and off for over 100 years (2). The approach must be capable of grinding, mixing, storing, and combusting COM with presumably only minor equipment changes on oil-fired boilers. DOE estimates that 56 000 m3 of oil (350 000 barrels) could be spared daily if a 50-50 COM was used to generate electricity. Of course, the ability of COM suppliers to prepare and deliver a stable suspension of COM at reasonable economic costs must be achieved if the concept is to be successful. This report reviews the various methods used to attain stable coal-oil mixtures. Various physical-chemical principles associated with each method of stabilization are also discussed.

Jan 1, 1981

The 86th Annual Meeting of the SME Minnesota section/74th Annual University of Minnesota Mining Symposium partnered with the Canadian Institute of Mining Metallurgy and Petroleum (CIM)?s Iron Ore Symposium for a historic joint conference, held this year in Duluth, MN, April 15- 17. One of a flurry of recent collaborations between SME and CIM, the joint conference was a natural fit for the conference held in the heart of the Iron Range. As CIM National President Terence Bowles said in his joint keynote with SME President Jessica Kogel, ?The U.S. imports $51 billion from Canada and Canada imports $38 billion the U.S.; that?s 50 percent of Canada?s exports and 51 percent of its imports.? The two countries? economies are linked, and nowhere more closely than in their iron ore mining activities. Kogel opened the conference with a plenary speech identifying the top 10 issues facing mining and how these issues present opportunities for mining companies. She said that it is important that the mining industry stay flexible and adapt to changing conditions, or it will go the way of the dinosaur. However, she said that these challenges can lead to new opportunities. For example, one of the major challenges facing mining is the current state of risk aversion among investors, which makes for ?less money in the pipeline.? However, this situation creates a better climate for mergers and acquisitions, which is another, less risky way to get funding. Likewise, another challenge globally is geopolitical risk; this challenge is likely to drive growth toward stable countries, which was good news for an audience composed mostly of Minnesota and Canadian mining industry personnel. One of the highlights of Kogel?s address was a triangle illustrating the interdependent nature of sustainable development and corporate social responsibility (Fig. 1). This triangle consists of four equal components: the social environment, transparency, local and global impact and future generations. The most important takeaway, Kogel said, was that sustainable development and environmental and social responsibility, while they do add to the cost of doing business, are no longer optional.

Aug 1, 2013

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

"Researchers at the Colorado School of Mines have studied the influence of headgate side ventilation controls near the longwall start-up room on the formation of explosive gas zones (EGZs) in underground coal longwall bleeder ventilated gobs. In a project funded by the National Institute for Occupational Safety and Health (NIOSH) researchers developed a Computational Fluid Dynamics (CFD) model to study the formation of methane-air mixtures in the gob, start-up room, and bleeder entries. The relative change in size and location of EGZs are examined in response to ventilation controls in the headgate side bleeder entries near the start-up room. Modeling suggests that adjustments to the ventilation controls can be made to minimize the size of the EGZ. However the EGZ may form in or around active working areas regardless of the ventilation control settings. Research found regulators on the crosscuts into start-up room and first entry inby can force air into to crosscuts outby the start-up room causing more air to flow through the gob. INTRODUCTION Underground longwall mine ventilation systems may operate with either a bleeder ventilated gob or a progressively sealed gob. Bleeder ventilated gobs must meet the standards for safe operation of the bleeder system by examining bleeder system effectiveness. As defined in the United States Mine Safety and Health Administration (MSHA) Program Policy Letter (PPL) No. P13-V-12 (MSHA 2013), the pillared area or gob is “any area where a reduction in pillar size has occurred during retreat mining” and includes the “caved and broken material, the interstices within the caved material, and the open spaces surrounding the caved material.” The PPL further states that the intended purpose of ventilating the gob is “to protect active workings from the hazards of methane accumulations …” The requirements for operating a bleeder system as stated in The United States Code of Federal Regulations (CFR 2013) Title 30 §75.334(b) is to pass ventilation air though the gob “and to continuously dilute and move methane-air mixtures [from the gob] away from active workings and into a return air course …” where the concentration cannot exceed 2 percent methane (CFR 30 § 75.323). Further clarification of the bleeder system as described in the PPL states the following: “A bleeder system includes the area from which pillars are wholly or partially recovered, bleeder entries, bleeder connectors, and all associated ventilation control devices that control the air movement through the area. Bleeder entries are air courses designed and maintained as part of the bleeder system.”"

Jan 1, 2015

By M. A. Giralico

A new generation of hydraulic efficient pumper and auxiliary impeller designs is the result of an extensive research program focused on improving the overall performance of optimized SX/EW plants. Combined with the proper scale-up, these optimized designs will greatly reduce aqueous and organic entrainment losses, reduce or eliminate air entrainment and crud formation, enhance mass-transfer and maximize the overall copper yield. Currently, these new pumper and auxiliary impellers are installed full-scale in numerous plants ranging in flow rates from 90 to 15000 G.P.M. and developed heads up to 51 inches. Operational results reported by the independent metallurgist at each processing plant are reporting the lowest entrainment results in the industry. Further R&D has just been completed on a new mixing configuration that separates the systems mixing and pumping requirements. Results from the system pilot test document further improvements in reduction of both chemical entrainment and crud formation, while keeping mass transfer stage efficiencies.

Jan 1, 1998

By J. Stachurski

Flotation tests were carried out on 6 coal samples of different rank as well as their oxidized samples. A mixture of diesel oil and alcohols was used in these tests. Surface oxidation caused a distinct decrease of the flotation recovery with some improvement in the grade The reduction in the recovery increased with increasing the concentration of the oxidizing agent. The floatability of low rank coals was affected by oxidation to a higher degree than medium and high rank coals. The recovery size curves of oxidized samples mere similar in shape to that of non-oxidized coals.

Jan 1, 1990

By Thomas L. Mell

Continuous processing plants handling liquids have achieved a high degree of centralized automatic control. Many chemical plants are operated from one room, with automatic control of the various process flow rates. These plants know from experience that automatic control can produce higher through-put, better uniformity of product, decreased operating costs and reduction of storage capacity, Plants which process materials in the form of bulk solids have not been able to use control to as great an extent, primarily due to the lack of measuring equipment capable of providing the same types of continuous automatic control available with liquid flow meters. This paper will describe a scale for measuring flows of bulk materials on conveyor belts which is particularly adaptable to remote centralized instrumentation and automatic control, and will also describe some typical control applications. Fig. 1 illustrates the basic method of measurement of this scale. A conveyor belt idler is supported on a rigid carriage which in turn is mounted in two anti- friction bearings on the conveyor stringers. The pivoted carriage is prevented from rotating about the pivot shaft by an electric strain gauge load cell connected between the carriage and a cross support. Increasing load on the conveyor belt increases the moment of the carriage frame about the pivot shaft, and proportionally increases the tension in the load cell. The belt speed is measured by a conventional d. c. tachometer generator driven from a pulley, usually on the return belt. The speed signal from the tachometer generator and the load signal from the load cell are combined to produce a signal proportional to the flow rate of material in tons per hour, or lbs. per foot, or equivalent units, It will be important to remember, in considering various control applications, that the flow rate of material on the belt is composed of these two component signals, namely the weight of material and the speed at which it is moving. The feed rate is then indicated and recorded by a self-balancing potentiometer of the type used for measuring temperature by means of thermocouples. These instruments may also be equipped with integrating mechanisms reading the totalized tonnage over a period of time.

Jan 1, 1958