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By J. S. Chung

As part of ongoing deep-ocean mining research, hydraulic transport systems as well as status of deep-ocean mining systems are reviewed in the aspects of manganese nodules and crusts from 800-6,000-m depth. The emphasis of the investigation of hydraulic transport is placed on the shape effect of particles on the pressure gradients and flowrates. Series of tests are being conducted to study the lift characteristics of a 2-phase vertically upward hydraulic transport of 2 types of small solid particles in a PVC pipe of 1-in (2.54 cm) diameter: irregular-shaped silica sands and equivalent spherical glass beads. Pressure drops and mass as well as volumetric flow rates were measured by electromagnetic (EM) flowmeter and mass flowmeter. The particle sizes used are 8-10 mesh. The results in turbulent flow range of 104 < Re < 105 show that pressure gradients or friction factors are smaller for the spherical beads than the sands. The larger the concentration of the particles are, the larger the pressure gradients become. The larger the particle concentration is, the less the effect of particle shape on pressure gradients becomes. The shape effect is greater for the minimum particle transport velocities than for the settling velocities.

Jan 1, 1999

By T. A. Farr, I. A. Gibbs, F. Guevara, S. R. Simms, G. Nojima

This paper describes an installation of a medium-voltage adjustable frequency motor drive (AFD) on a high starting torque regrinding mill. This type of application is typically found in the mineral industry dealing with hard ore. The AFD electrical architecture is introduced from line to load. The type of closed loop encoder feedback motor control algorithm is briefly described. The results of the AFD motor identification auto-tuning are compared against the manufacturer’s supplied data. The motor drive performance results are shown for pre-ramp DC fluxing, high starting torque with overload current, excessive load torque stall condition, and blocked rotor. The instrumentation and arrangement for the two watt-meter method to capture low frequency data are presented. The data shown is from the input power quality meter, the AFD computer tool, the output motor protection relay, an oscilloscope, and load shaft connected strain gauge (rotating telemetry for torque assessment). These types of high starting torque constant torque loads are found in mining and process industry applications employing AC adjustable frequency drives. Using field results should help demystify the use of voltage matching output transformers in AFD applications including constant torque loads

Mar 2, 2022

By K. E. Burgher

Since World War II, the need for the use of explosives in construction, mining, and quarrying near congested urban areas has increased dramatically. Often times a coal mine, once isolated from a city, finds itself surrounded by residential and commercial structures. The United States Bureau of Mines and others have researched blast design to a point where ground vibration and airblast damage can be avoided. A problem still exists, however. It is the fact that people often react to only the loud noise associated with a blast although it may not cause damage. Most often it is the concussion of a blast, less than 20 hertz and inaudible, that produces damage. Public fear from the "startle" and "fright" of loud blast noise greater than 20 hertz leads to the complaints which are generally unfounded. See Thackray, Touchstone, and Baily (1975) for a further discussion of the startle effects of loud sudden noises. When blasts are designed in accordance with U.S.B.M. specifications, management generally has little to worry about with respect to damage claims. Complaints, however, still arise when the noise is accentuated from the blast. It is meteorological conditions which dictate how the sound levels will propagate. Some mines use small pilot test shots (generally one-two lbs) to determine when atmospheric conditions favor sound travel.

Jan 1, 1987

By Bruce A. Kuyper

Routine core drilling at the Cove deposit failed to confirm gold-silver grades and length of intercepts observed in reverse circulation drilling. A drilling program was designed to ascertain whether the disparity was due to problems with reverse circulation drilling techniques, core drilling techniques, or the erratic nature of the gold-silver mineralization. Special sampling devices and core drilling methods were employed. Data obtained from core-reverse circulation twins showed that down-hole contamination during reverse circulation drilling accounted for much of the variation between reverse circulation and core drill results. Down-hole contamination occurred as a result of high ground-water inflows eroding friable vein material from hole walls.

Jan 1, 1991

By Richard L. Bullock

Believe it or not, mine evaluation and feasibility studies are as old as the industry itself. In the first recorded writing on mining by Agricola (1556), he gave several clues as what to look for in evaluating a mine, to determine if it was economically feasible. Below is the guidance from Agricola, with my interpretation of what he would include today. Now a miner, before he begins to mine the orebodies must consider seven things, namely: ? The situation (the geography/topography). ? The conditions (the geologic/mineralogic and mining conditions). ? The water (availability, hydrology and ownership). ? The roads (plus the railroads, power lines, all other infrastructure). ? The climate (the weather-rainfall/environment). ? The right of ownership (the land and legal entitlement). ? The neighbors (the social environmental concerns of the area). It is amazing how much of his guidance has not changed in 455 years. Yet Agricola gives no guidance on determining the correct cost, or determining the correct commodity pricing. But he does give a few words of caution on the related ethics involved on buying mineral properties: ?A prudent owner, before he buys shares, ought to go to the mine and carefully examine the nature of the vein, for it is very important that he should be on his guard lest fraudulent sellers of shares should deceive him.? Three hundred years later (1866), to further amplify this point, in the most famous thing that Mark Twain never said, as an introduction to a lecturer to an audience of gold-miners at Red Dog, CA, the famed author/humorist allegedly described a mine as ?a hole in the ground owned by a liar? (Farrar & Rinehart, 1935). So, one might conclude that between these two dates, the mining industry did little to improve its reputation. Unfortunately, since Mark Twain allegedly made those remarks, we have not done near enough to gain accountability for the mineral industry.

Jan 1, 2011

By Rahul Singh, Sunil Kumar, Erich Dohm, Maoming Fan

The rapid increase of P2O5 use for food, biofuels, and LiFePO4 batteries etc. accelerates the depletion rate of phosphate reserves. In the phosphate industry, a significant amount of ultrafine phosphate has been discarded as slime tailing due to processing difficulties. The major problems associated with ultrafine particle flotation are low probability of bubble-particle collision and adhesion, and high probability of unwanted gangue particles entrainment. This paper investigates the enhanced ultrafine phosphate particle flotation probability by Eriez’ CavTube generated fine/ ultrafine bubbles and the improved flotation selectivity by wash water etc. Ultrafine phosphates with various gangue minerals of quartz/muscovite, calcite/dolomite, and iron/ silica were studied. Microscopic observations show that the entrained ultrafine gangue minerals can be minimized by using wash water in column flotation. A three-factor threelevel central composite experimental design was conducted for ultrafine phosphate flotation. For comparison, both benchtop mechanical cell and laboratory column flotation tests were performed at their optimal respective flotation conditions. Using Eriez CavTube column flotation technology for Industries Chimiques du Senegal (ICS) ultrafine slime tailings, a concentrate grade of 36.0% P2O5, was achieved at 89.4% P2O5 recovery. Improved flotation performance was achieved using column flotation as compared to benchtop mechanical cell flotation. The benefits of Eriez’ column flotation technology realized from this study include the high P2O5 grade and recovery.

Feb 1, 2024

By Marcel F. DeGuire

Pilot plant operations are described for the treatment of manganiferous zinc concentrates from the Gamsberg ore deposit in South Africa via conventional electrolytic zinc processing. Two methods were employed for the control of excess manganese ions in the pilot plant electrolyte involving (1) chemical oxidation and (2) anodic oxidation. The chemical oxidation method for manganese control was very successful. It also was found that the addition of manganese dioxide ore was not required for oxidation of ferrous iron during the neutral leach or jarosite precipitation steps. A new method (JAR process) for iron removal also was tested in the pilot plant.

Jan 1, 1978

By Vishnu S. Gupta

A modular computer program APEX (AMAX Process Evaluation Executive), has been developed at AMAX Extractive R&D, Golden, Colorado to facilitate rapid simulation of steady state material and energy balances of existing and/or proposed metallurgical process flowsheets. Currently, APEX is being used for the design, analysis, and evaluation of several of AMAX?s Nickel, Molybdenumand Tungsten processes. A unique feature of APEX is that it allows specifications of flow rates and compositions for different solid size fractions in addition to aqueous organic and gaseous phases. Thus, a metallurgical process which may involve crushing, grinding, flotation, leaching, washing, solvent extraction, precitation and refining operations can be simulated in a single computer run using APEX. APEX requires two input data files. The first is a process data file which includes physical and thermodynamic properties of the various chemical components of interest. This data file is unique to the process under study and does not require changes for alterations in the process flowsheet. The second data file is specific to a simulation case and includes descriptions of the flowsheet, various feed streams and the process equipment&apos;s operating conditions. In addition to temperature, pressure and percent solids, calculated information for each stream includes weight and volumetric flow rates, chemical compositions, specific gravities and enthalpies of solid, liquid and gas phases. For each process equipment in the flowsheet, APEX prints its operating conditions and detailed information about the streams that enter and leave the unit. Models of several general unit operations are preprogrammed in APEX. Also, the modular design of APEX permits quick and easy additions of simulation models which are specific to new and/or unique process operations. To study process stability and optimization, APEX permits several cases of a flow-sheet to be run together. Three simulations of the Moa Bay Nickel process have been excluded to illustrate the ease and flexibility of using the APEX system.

Jan 1, 1980

By Y. C. Lo

This paper presents the development of ultrasonic grinding technology for material and mineral processing. The principles underlying this new technology, as well as their implementation in two laboratory scale devices are described in detail. Ultrasonic grinding experiment results are discussed with respect to operating variables and the achieved product sizes. Special attention has been given to the electrical energy consumption of the grinder, and an attempt to compare its efficiency with tumbling mills has been made. A mechanical system capable of measuring the specific grinding energy is also described.

Jan 1, 1991

By Gerald H. Luttrell, Seyed Hassan Amini, Aaron Noble

One of the most important processing engineering tools for designing mineral processing facilities is linear circuit analysis. This technique, originally conceived and developed by Meloy, Williams, and Fuerstenau nearly four decades ago, provides fundamental insights regarding how unit operations interact and respond when arranged in multi-stage processing circuits. Researchers have successfully utilized this tool to improve the operating performance of industrial processing circuits incorporating coal spirals, magnetic separators, mineral spirals, and eddy current separators. More recently, advanced versions of this tool have also been developed to provide a standardized framework for circuit mass balance calculations, to output exact analytical solutions to mass yield and value-based efficiency expressions, and to estimate uncertainty propagation in separation circuits. This article reviews the historical development of linear circuit analysis, describes how the technique has evolved to address more complex circuit design problems, and presents industrial case studies that highlight the importance of this process engineering tool.

By Steven W. Hunt, Glen R. Frank

Assessment of abrasivity and cutter life are necessary to properly manage risks when tunneling in mixed face ground which includes ground with cobbles and boulders. Maximizing cutter life requires: (1) abrasivity and strength parameters for soil matrix and rock clasts, (2) methods of combining both, (3) proper selection of cutters and (4) modified TBM operation including use of boulder detection methods from the TBM to help make operation decisions. This paper presents approaches for addressing these factors sufficiently to improve tunneling success in mixed-face and cobbly-bouldery ground. Current laboratory abrasivity testing will be assessed along with equivalent quartz content correlations to soil matrix and rock clast abrasivity. New approaches to combining abrasivity testing of both the soil matrix and rock clasts for various cobble and boulder volume ratios will be suggested to estimate cutter life and intervention intervals. Methods for detecting boulders and using detection data to modify TBM operations to minimize boulder impacts are provided.

Jun 13, 2021

By R. D. Wunder

The Chino Mines Company, a Kennecott-Mitsubishi partnership, located in Hurley, New Mexico, recently completed a $405 million modernization of its mine, concentrator, and smelter facilities. The mine/ concentrator modernization commenced in 1980 and the smelter modernization began during 1982. Modernization of the mine and concentrator facilities involved increasing the mining rate from 98 kt/d (108,000 stpd) to 152.2 kt/d (167,800 stpd). Ore mining was designed to increase production from 20.2 kt/d (22,300 stpd) to 34.0 kt/d (37,500 stpd). A new concentrator was constructed near the mine using semi-autogenous grinding. The new smelter uses the INCO flash smelting process, increasing capacity by 40.8 kt/a (45,000 stpy) to 99.8 kt/a (110,000 stpy) of salable copper.

Jan 1, 1985

By Ross W. Smith

In recent years there has been a considerable amount of research work done relative to the effect of pretreatment and aging in water on the surface properties of both simple metal oxides and more complex oxides such as the silicate minerals 1-6. Of particular interest is the work of Somasundaran6 who states that after preparing minerals by size reduction and washing with dilute acids "... it is essential to treat it (the mineral) with water in order to remove any effects of leaching itself." Somasundaran also states, "... it is advisable to use a solution close to the point of zero charge for conditioning purposes." Parksl notes that, "Dehydration, dehydroxylation, and increased crystallinity can be expected to decrease the PZC. The presence of anionic impurities or of pH-independent potential determining ions will decrease the PZC. Cationic species will increase the PZC." Healy and Jellett4 believe that in the Zn0-water system "the surface charge of Zn0 in water and each pH is determined by the concentration and adsorption of each hydrolyzed (charged and uncharged) Zn(II) species." Finally, according to Parks 2, "The PZC of an unaltered com¬plex oxide in a system devoid of specific electrolytes is approximately the average of the PZC&apos;s of its component oxides... Equilibration with water results in loss of mono and divalent cations by exchange with H+, thus a loss of influence on the PZC by those cations, i.e., a shift in the PZC with time in the direction of that remaining oxide. The present paper investigates the change of point of zero charge (PZC) of a number of simple oxides and several complex oxides as a function of aging time in water. In some cases acid pretreatment of minerals was performed. However, in most cases the minerals were not acid pretreated. In several systems pH change as a function of aging time in water was monitored.

Jan 1, 1972

A new analytical approach for characterizing and improving the performance of ball milling is presented. Individual ball mill circuit design and operating variables can be related to overall circuit performance through two distinct parameters for classification and breakage. The ball mill circuit functional performance equation is presented. Applications in the industrial plant and in the research field are discussed.

Jan 1, 1990

The National Mining Hall of Fame and Museum (NMHF&M) will induct the 2013 National Mining Hall of Fame class on Sept. 14, 2013. The ceremony will take place at the Brown Palace Hotel in Denver, CO. Representing the domestic and worldwide metal production, education, and health and safety sectors of the industry, this year?s five inductees cover a diverse cross-section of the mining industry. The inductees are: Charles F. Barber, Donald W. Gentry, Patrick H. O?Neill, Milton H. Ward and David A. Zegeer. They will join 218 other mining industry pioneers when they are formally inducted into the National Mining Hall of Fame at the 26th Annual Induction Banquet and Ceremony. They were selected for being visionaries, leaders and ambassadors, both within their own sectors and across the industry at large. Barber was a top executive at leading U.S. metals producer Asarco from 1956 to 1982. During his tenure, Asarco responded successfully to the demanding requirements of new environmental legislation in the United States and to changing concepts of foreign investment in mining, especially in Latin America. Gentry?s career took him from being a working mining engineer, to renowned mining educator, to president and chief executive officer of a mining company. As an educator, he had a positive impact upon hundreds, if not thousands, of new mining engineers and many others who took his short courses in mine economics. During his years in South America, O?Neill did everything from supervising operations of 15-bucket ladder gold dredges to becoming president of International Mining Corp. As an executive, he emphasized provision of education and training to local people working at mine sites for which he had responsibility. Ward?s experience covered the world and spectrum of metals, minerals and ores, ranging from A to Z (antimony to zinc and Australia to Zambia). He was president, chairman and chief executive officer of Cyprus Amax Minerals from 1992 to 1999, and he was president and chief operating officer of Freeport-McMoRan from 1983 to 1992, during which time he was instrumental in developing Freeport?s world-class Indonesian operations. Zegeer dedicated his mining career to protecting the health and safety of miners as a corporate executive, head of the U.S. Mine Safety and Health Administration (MSHA) and community leader. His tenure at MSHA coincided with a period of remarkable progress in U.S. mining safety .NMHF&M Board of Directors Chairman Paul C. Jones said: ?The five outstanding gentlemen being honored this year as inductees into the National Mining Hall of Fame are classic examples of the leadership and work ethic that has made America?s mining industry the world leader in technically sound, environmentally and socially correct, and economical mineral production that sets the standards for mining worldwide. We are very proud to add these five legendary gentlemen, who have demonstrated their sound technical and management skills to advance society on a worldwide basis, to our current list of 218 inductees being honored by the National Mining Hall of Fame.? 2013 Prazen Award winner ? The Nevada Mining Association is the recipient of the 2013 Prazen Living Legend of Mining Award

Aug 1, 2013

By John R. Marks

Introduction An engineer is a builder and a problem solver. He uses knowledge of the properties of matter and energy to furnish the needs of society. Engineers form the bridge between scientific researchers and the general public, most of whom are technologically illiterate. Mining, metallurgical, and petroleum engineers extract minerals from the ground and process them into usable forms. Then, other engineers further process them into society&apos;s needs. Minerals engineers deal with more uncertainty than other engineers. Each ore deposit has its own personality and each ore is metallurgically unique. Minerals engineers, therefore, must be flexible, often applying larger safety factors and contingencies than other engineers, and frequently functioning as a jack of all trades. A minerals engineer can work in coal, oil, oil shale, base metals, ferrous metals, precious metals, industrial minerals, strategic minerals, or in exploration. Other mining jobs include banking and financing, education and research, marketing and sales, and government. As a minerals engineer, you may be among the first to work on the ocean floor or the moon. College Preparation A difference between college and industry is the type of problems to be solved. A typical college problem has an exact answer derived from given information. An industry problem is more apt to have a solution chosen from a number of alternatives. Information required for the solution is not given. It must be measured, calculated, looked-up, estimated, or otherwise derived. Solutions involve trade-offs, economics, and human factors, as well as application of physical laws and theory. When a college problem is answered, you move on to the next one. In industry, however, the headaches may just be starting with the implementation of the solution. Students often complain that they see little use for the theory they are learning. This is valid. A good professor will link theory and practice. Another difference between college and industry is the price of failure. In college, you can make a half-hearted effort in an assignment and take your C or D. On the job, however, poor engineering results in potentially effective projects being rejected and unsound projects being undertaken. Poor performance results in cost overruns, schedule holdups, oversights, disgruntled employees, irate bosses, unsafe structures, and unreliable systems. The costs are time, money, and possibly lives. The student pays the university for his work - not the other way around. So the rewards for good schoolwork often seem nebulous. But education must be viewed as an investment. Working for good grades will help you think better, learn more, receive better job offers, and perform more effectively on the job. There is no substitute for hard work. Avoid taking the easiest electives. If you desire a more liberal education or dislike rigorous physical sciences, mathematics, or engineering courses, change majors. Remember, you are training to be an engineer, not a computer programmer or market analyst. At least one summer of industry employment is necessary for minerals engineering students. The sooner you gain actual experience, the sooner you will know whether to change majors. Most large companies hire students during summer. It is best to send out applications around Christmas break. First and second year students usually work as laborers. Upper-classmen may work as engineering technicians. Students must sometimes choose between returning to a company at a higher position or trying a different company at a lower position, for more varied experience. Both alternatives have advantages. Do your best on these summer jobs. The company is watching. If you do well, the chances are good you will get a job offer when you graduate. Good references are important when you begin job hunting. Interviewing occurs near the end of your school career. The standard procedure is to send your resume with a cover letter to each company you are interested in. The resume for a graduating engineer with little experience need not exceed one page. The cover letter must be written for the individual company.

Jan 2, 1985

By J. Drelich

The wetting behavior of liquid polymers at solid surfaces and the adhesion forces involved at polymer-filler interfaces should always be considered in the fabrication of high quality polymer composites, including those made with mineral fillers. Spontaneous polymer spreading over the filler surface is a basic condition in the fabrication of the polymer-mineral composites. In this regard, the wetting and adhesion characteristics of polymer-mineral systems are reviewed in this contribution. It appears that several aspects of wetting phenomena at mineral filler surfaces are not well described in the literature and require further systematic study. Specifically, it is clear from this review that efforts should be made to determine the effects of mineral surface contamination (including surface hydration) on wetting and adhesion phenomena, and to determine the wetting characteristics of molten polymers at mineral filler surfaces. It is expected that any improved fundamental understanding of wetting and adhesion phenomena for the polymer-mineral composites will provide the basis for further technological development.

Jan 1, 1995

By Basak Anameric

This study reports preliminary feasibility investigations for utilization of the selective carbothermic reduction and smelting (SCRS) processing scheme to beneficiate low-grade iron-manganese (Fe-Mn) mineral deposits from MN, USA. The study includes laboratory-scale demonstrations using an induction furnace and production of various products by manipulation of operational parameters. The products include alternative iron (Alt Fe), high carbon ferromanganese (HC FeMn), alternative silicomanganese (Alt SiMn), and upgraded manganese concentrate (Mn conc). All of these products have commercial value and can be used in various applications as raw materials.

Nov 23, 2020

By J. A. M. Cano

An extensive research work was developed by Samarco Mineracao S/A to study the quality characteristics of blast furnace pellets produced with high content of MgO. Comparative blast furnace simulation tests were conducted both in Samarco and foreign laboratories. The objective was to evaluate the behavior of high MgO and normal Samarco pellets in the blast furnace operation. Additives such as dolomitic hydrated lime, dunite and magnesite were used for increasing pellet MgO content. The test results showed that pellets produced with high MgO content are similar in quality to normal Samarco Pellets.

Jan 1, 1991

By Todd Grounds, William R. Reed, VASU GANGRADE, Michael Shahan, Garron Ross, Kunal Singh

Roof bolter canopy air curtains (CACs) are gaining acceptance as a respirable dust control device that can provide roof bolter operators with protection from overexposure to respirable coal mine dust. Both lab and field studies on the effectiveness of roof bolter CACs have been published. Field studies have shown the effectiveness to be variable. However, in all previous field studies, none has been conducted when the roof bolting machine operates downwind of the continuous miner (CM)—a scenario for which the CAC was designed to provide respirable dust control. This study, performed by researchers from the National Institute for Occupational Safety and Health (NIOSH), was conducted to test a CAC on a roof bolter machine operating downwind of the CM. The results of testing demonstrated that the roof bolter CAC can effectively provide respirable dust protection for roof bolter operators with dust control efficiencies ranging from 11 to 40%.

Oct 14, 2020