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By J. F. Shea, O. F. Tangel

Battelle Memorial Institute participated in a program for the General Services Administration aimed at developing a nickel-cobalt separation process that could be integrated in the Nicaro nickel plant. At the time the programwas being carried out, the Nicaro process was a straight-through operation, in which the ore was reduced and leached, after which the pregnant solution was boiled to produce a so-called "bulk precipitate" which contained virtually all of the nickel and cobalt which had been dissolved in the leaching step. The weight ratio of nickel to cobalt in Nicaro ore is approximately 15 to 20:l. The weight ratio of nickel to cobalt in the finished product had to be 100:l or higher to meet specifications. Because the Nicaro process embodied no nickel-cobalt separation step, the only way that a bulk precipitate of the specified nicke1:cobalt ratio could be produced was to so adjust roasting and leaching conditions that nickel would be selectively leached and most of the cobalt would be rejected with the tailings. The required selectivity, however, was achieved at the expense of nickel recovery, which was 5 or more per cent less than might have been obtained with the existing equipment, utilities, man power, etc., had selectivity been no object. The over-all purpose of the program was to develop a separation step that could be fitted into or onto the Nicaro facilities and which would permit the manufacture of a product that would meet the desired specifications and still permit the recovery of a maximum amount of nickel. Battelle suggested that this might be accomplished by reprocessing off-specification bulk precipitate and specifically suggested the process based on ammonium sulphate leaching followed by hydrogen reduction of the leach solution according to techniques developed commercially by Sherritt Gordon Mines Limited. Such a process would not only satisfy the objectives of the research but would present two additional advantages. (1) It would produce a separate cobalt product which could be further processed into metal, alloys, oxides, or salts. (2) It would yield nickel in metallic form which might be more generally marketable and command a slightly higher price per unit of nickel than the Nicaro oxide product. DESCRIPTION OF THE PROCESS Figure 1 is a flowsheet of the process. The essential features are: (1) Extraction of about 97 per cent of the nickel and about 85 per cent of the cobalt from bulk precipitate by a principal leach with ainmonium sulphate solution (Step A). Extraction of virtually all of

Jan 1, 1961

By Arthur F. TQggQrt

THE approximate status of education in ore dressing in 1871 is reflected by Rossiter W. Raymond in an article written at that time presenting the curricula and descriptions of the laboratories at the various mining schools in the United States. For the most part, the curricula in which ore dressing was taught were for mining engineering. They comprised courses in geology, mining, and pyrometallurgy about equal in point or credit weights; a short course in ore dressing, and a somewhat longer course in assaying; and courses in surveying, hydraulics, power, and strength of materials-all superimposed on a broad foundation of physics, chemistry, and mathematics. Some curricula contained a fair content of the humanities. Then, as now, the emphasis on fundamentals was greater in the older colleges and universities. The report on the Columbia School of Mines, then relatively young, emphasized that a large percentage of its students were college graduates. As technical and scientific knowledge grew, first metallurgy and then geology were set up as separate curricula. So far as curriculum designation is con-

Jan 1, 1947

By Sanjiv Dhanjal

"Often mineralogy dictates the physical properties of a material rather than chemistry. This in turn affects how that material behaves in a process plant, and whether optimum conditions for refining one mineral are different to those for refining another. For example how does refining copper from chalcopyrite differ to refining copper from bornite?Minerals are naturally occurring inorganic solids that have a definite chemical composition and an ordered atomic (crystalline) structure. X-ray diffraction is a common and highly developed method to identify and quantify minerals. X-rays are fired onto a material and the mineral is identified by the angles where the diffracted X-rays are in phase.Most X-ray analyzers are laboratory based. A sample is prepared and analyzed by a detector that travels in an arc to collect the diffraction pattern. COSMA has a curved detector which picks up the complete x-ray pattern instantaneously. Therefore, material is collected and transported through the machine where is it is analyzed continuously.COSMA measures about 0.5 tons of material per day, while laboratory analyzers measure a few grams at a time. Real time data trends are produced allowing for improved process evaluation and automatic control. The COSMA on-line system has taken X-ray diffraction out of the laboratory into the field.There are a number of systems in operation in cement production. It is recognized that on-line mineral analysis has a role in many other processes. This paper presents the technology and invites further discussion should the technology be beneficial to members of the audience.INTRODUCTIONThis article describes COSMA, a system that provides direct and continuous on-line mineral analysis using X-ray diffraction in the field. While X-ray diffraction is a common technique used in mineral analysis, the time from sampling to analysis can be hours and plant operators typically do not get the data in time to control a process or respond to an upset. COSMA provides rapid measurement, analysis and feedback of data, in real time. This provides powerful information that can be used to optimize operation, thereby reducing costs and increasing quality."

Jan 1, 2009

By Lawrence Williamson, Randall J. Essex, David P. Field

As part of a $2.2 Billion bridge project that will link Indiana and Kentucky, an interchange project northeast of Louisville will require the mining of a 6-lane tunnel system about 2,000 ft long in order to cross beneath the historic Drumanard Estate. This paper will discuss preliminary engineering that has been undertaken to compare two-bore and three-bore layouts, the planning of an exploratory tunnel facility, and the potential for including a test chamber to investigate the ability of high capacity roadheaders to mine the 22,000 psi limestones.

Jan 1, 2005

By T. J. Serenko

The epithermal deposit is hosted by Tertiary volcanic rocks that lie between mid-Miocene normal faults of the Northern Nevada Rift. Petrographic, laser-ablation and metallurgical observations suggested that the gold occurs in two principal forms: native (and electrum) and disseminated in arsenopyrite. It was proposed that gold is distributed between two parageneses with distinct mineralogical associations. Detailed downhole geochemical study supported the observations. Concentrations of Au, Ag, As, Sb and Se were determined from drill core and reverse-circulation cutting composites and contoured on cross-sections. Gold was indeed shown to have a bimodal distribution with the two parts separated spatially and perhaps temporally, implying that two separate genetic processes acted to concentrate gold at Mule Canyon

Aug 1, 1995

By G. Duncan, K. Winther, R. Ericsson

Distinct trends in grinding mill technology have emerged in recent years. In an effort to optimize overall mill performance for the needs of the End User, broad measures of logistical speed, process flexibility, operational risk, and overall costs now exert greater influence on the specification of grinding equipment. As a result, innovative alternatives to conventional grinding mill structures, supports, drives, feed, and discharge configurations are now being offered and selected with greater frequency. This paper investigates these trends in grinding mill technology, utilizing optimization and decision-theory techniques. In particular, the paper considers how specific advances in process design, product engineering, manufacturing techniques, and mining operations continue to relax technological constraints, enabling further mill innovation. In this context, a methodology is presented, illustrating how proper selection and specification of grinding mill components and configuration can target an optimization of the four End-User performance measures listed above.

Jan 1, 1999

By F. E. Joyce

This paper describes the development of a process for producing manganese and iron pellet concentrates from low-grade manganiferous iron ores of the Cuyuna range by a two-stage sulfatization-reduction roast. First, the manganese minerals (7.5 percent manganese) were converted to water-soluble manganese sulfate by roasting in sulfur oxide gases at 700° C, then, the hematitic iron minerals (31 percent iron) in the hot sulfatized are were reduced to magnetite with simulated reformed natural gas in the temperature range of 350° to 425° C. Batch tests were made in a 3-inch-ID by 6-inch-long, gas-heated, stainless steel retort, and continuous countercurrent experiments were performed in a 2-inch-ID by 10-foot-long, electrically heated shaft furnace. Manganese sulfate was removed from the roasted product by leaching with water, and over 90 percent of the manganese was recovered in an oxide product (65 percent manganese) obtained by precipitation, drying, and thelmal decomposition of the sulfate. An iron oxide concentrate (60 percent iron) with an iron recovery of 75 percent was obtained from the water-insoluble residue by magnetic separation.

Jan 1, 1973

By L. A. Eros

The U.S. Bureau of Mines and Western Fuels Utah, Inc. entered into an agreement to plan, install, and evaluate a micro-computer based monitoring and control system at Deserado Mine, an underground coal mine. The U.S. Bureau of Hines contracted the Colorado School of Mines (CSN) to independently evaluate the project. CSM evaluated and documented costs, benefits, problems, and management and labor perceptions in this report. Recommendations are provided for mine operators and monitoring system vendors considering future installations.

Jan 1, 1986

Wastewaters from Mining Projects both gold mining and coal mining generally have minerals in solution or very fine material which does not settle out quickly. These waters in the past have been discharged into the nearest water course and caused extensive pollution.

Jan 1, 1986

By R. P. Mohring

The South African Coal Industry had its beginnings in the Eastern Cape in 1859 when coal was mined to satisfy the fledgling settlements in the Eastern Cape. The growth in the industry was relatively slow up to the early 1970s when, firstly, the export business was expanded coupled with a major increase in the quantity of coal converted to liquid fuels and utilized for power generation. To meet this increased demand the industry developed many new operations employing the latest mining technology and systems. Coal production in South Africa reached 204 million tons in 1996 and revenue from exports reached R8 billion making it the second-largest foreign exchange earner after gold. In his address Rick P. Mohring describes the role coal plays in the international energy scene and outlines South Africa?s position as a producer and consumer of coal, and the challenges facing the industry. A wide range of steam-coals are produced to satisfy both the local market (power generation, coal conversion and the metallurgical industry) and the export steam-coal market. South Africa is in a unique position regarding the export market as it is still a relatively low-cost producer and is geographically well-placed to play in both the European and Far East markets. There are, however, a number of challenges facing the industry. To retain our competitiveness in the international market, ways of minimizing the cost pressures caused by high-cost inflation, increased environmental protection obligations and a decreasing quality resource base need to be sought. Locally the coal mining industry has a major role to play in Eskom?s goal of reducing the real cost of electricity by 15% in the next three years. Safety and health, productivity and the adaptation of the latest technology are issues being addressed by the industry to maintain its dominant position within the South African economy.

Jan 1, 1997

By D M. Hunter, S M. Iveson, K P. Galvin

For low density materials such as coal, density-based fractionation of particles via the sink-float method is relatively simple due to the availability of liquids of suitable density; however, for high density minerals, suitable heavy liquids are less available and those that are available are expensive and pose significant hazards. At best, sink-float separation can be performed up to densities of 4400 kg/m3 with the use of Clerici’s solution at elevated temperatures. Hence the direct measurement of grade-recovery and density-partition curves is problematic. Therefore, in most cases, beneficiation plants must rely on methods such as QEMSCAN, density tracer particles or very limited information to guide them in the design and optimisation of their plants.This paper describes a density-fractionation method utilising laminar flow through a system of parallel inclined channels to generate a series of overflow fractions at different flow velocities. Here the particles are subject to precise hydrodynamic forces with minimal dispersion or mixing. The size distribution of each overflow fraction at a given flow velocity is obtained using a laser particle size analyser, and combined with a laminar flow model to deduce the corresponding density distribution. The paper describes the application of the method to measure the separation achieved using a REFLUX Classifier to obtain the corresponding feed, product and reject ‘washability curves’, and in turn the full partition surface. Approaches used to corroborate the findings are discussed.CITATION:Hunter, D M, Iveson, S M and Galvin, K P, 2017. A batch elutriation technique for the density-based fractionation of iron ore, in Proceedings Iron Ore 2017, pp 195–104 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By B Harvey

Achieving community and stakeholder endorsement during life-of-mine planning and implementation requires a business-connected approach, as opposed to charitable giving, disconnected offsets and environmental adventurism.CITATION:Harvey, B, 2014. Extractive companies, development and environmental agendas, in Proceedings Life-of-Mine 2014 , pp 19–22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By S F. Simmons

The Ohaaki Rhyolite and the Rautiwiri Breccia are two volcanic units occurring in the shallow and deep parts of the Broadlands-Ohaaki geothermal system. Alteration of these units by chloride waters results in distinct mineral assemblages that also have distinct whole rock compositions. The Ohaaki rhyolite is altered to an assemblage dominated by quartz, adularia, illite and pyrite as a consequence of silica, potassium and sulfur metasomatism. Locally, these rocks contain up to 0.5 ppm Au. The Rautiwiri Breccia by contrast is altered to an assemblage dominated by albite, adularia, quartz, illite, chlorite and pyrite in association with modest sodium metasomatism. Whole rock oxygen isotope compositions of altered rocks range between 3.3 and 7.5 ë, and are generally lower compared to their fresh rock equivalents having values of 9.5 to 10.6 ë; the result is broad pattern of lower values with increasing alteration intensity.

Jan 1, 2002

Lower greenschist quartzo-feldspathic schists within the N-S trending Earnslaw Synform of the Upper Wakatipu area are pervaded by late-stage quartz filled extensional and extensional shear fractures, with quartz-scheelite lodes infilling normal faults. Exposed veins/lodes mapped over at least 1000 km2 define a paleoflow system developed during late metamorphic exhumation of the schist. Both veins and lodes have consistent angular relationships to the schist foliation independent of their location on the Earnslaw synform. Unfolding the synform leads to a regional subhorizontal foliation and a systematic set of subvertical quartz veins striking NNW extending over a depth interval >5 km, striking parallel to a set of normal faults hosting the quartz-scheelite lodes. The structures define an extensional regime with s1 sub-vertical, s3 oriented WSW-ENE, a low differential stress, and suprahydrostatic fluid pressures.   The quartz-scheelite lodes (<2 m thick) occupy faults which cross-cut the quartz veins, and are traceable for a few hundred metres, at most. The lodes consist of laminated and/or massive quartz, slivers of crushed and folded schist, random and discontinuous lenses of scheelite with clay selvages separating the lode from relatively undisturbed wallrock schist. Textural evidence suggests that slip developed incrementally with total displacement on faults during lode formation on the order of a few ten's of metres.   The distribution of Glenorchy veins demonstrates broad scale hydrothermal flow through low-permeability schist, channelled within dilatant mesh style structures comprising interconnected shear and extension fractures. Flow through the lodes was likely derived from the greater surrounding area via the interlinked network of fractures and focused into the low displacement shears. Available evidence suggests the system developed together in a uniform extensional stress regime toward the bottom half of the seismogenic regime.

Jan 1, 2001

By Ahmad Ghahreman, Lin Li

Silver and cupric ions have been proven to play the roles of catalysts to promote the oxidation kinetics of chalcopyrite in acid solution. In this study, the interaction between silver ions and cupric ions during ferric leaching of chalcopyrite in sulfuric acid solution has been investigated. The electrochemical study by Tafel analysis showed a significant boost of dissolution rate for chalcopyrite dissolution in Fe3+- Cu2+ containing sulfuric acid solution after Ag+ was added in the solution. For 10 ppm Ag addition, the dissolution rate of chalcopyrite increased to 7.94 ×10-6 A/cm2 from 3.2 ×10-7 A/cm2, when Ag+ was absent. On the other hand, the effect of Cu2+ on the dissolution of chalcopyrite in Fe3+-Ag+ containing sulfuric acid solution was not obvious from electrochemical measurements. The chalcopyrite leaching tests in different acid solutions showed that silver addition had an obvious catalytic effect on promoting chalcopyrite dissolution. Comparing the leaching rates of chalcopyrite leached in Fe3+ containing, Fe3+-Ag+ containing, Fe3+-Cu2+ containing and Fe3+-Cu2+-Ag+ containing sulfuric acid solutions, it was found in Ag+-Fe3+-Cu2+ containing sulfuric acid solution, the leaching rate was highest among all the aqueous acid systems. Further leaching tests suggested that with increase of the Ag+ concentration from 0 to 20 ppm, the leaching rate of chalcopyrite in Ag+-Fe3+-Cu2+ containing sulfuric acid solution also increased and reached 57.62% with 20 ppm Ag+ addition after 24 h. INTRODUCTION Chalcopyrite is the most important copper mineral in copper hydrometallurgy and it accounts for nearly 80% of the universal copper resource (Olvera, Rebolledo, Mora, Dixon, & Asselin, 2018). The hydrometallurgy of chalcopyrite has been intensively studied with emphasis on solving the slow dissolution kinetics of chalcopyrite in acid environment. A variety of aqueous systems, such as sulfate (Hiroyoshi, Miki, Hirajima, & Tsunekawa, 2001), chlorides (Liu, Chen, & Yang, 2017), and ammonia (Hua et al., 2018) have been studied to improve copper leaching. From another perspective, chalcopyrite leaching studies have indicated that the mechanism of chalcopyrite dissolution in acid solution is essentially electrochemical (Li, Kawashima, Li, Chandra, & Gerson, 2013). Therefore, extensive studies have recently been carried out to explain the dissolution kinetics of chalcopyrite in different media by various electrochemical techniques.

Jan 1, 2019

The 1965 Lignite Symposium, the Louth in a series and the third sponsored by the University of North Dakota and the Bureau of Mines, was held at Bismarck, N. Dak., on April 29-30, 1963. These symposia provide a forum for those interested in the technology and utilization of solid fuels, especially lignitic coals. As part of the meeting, a 200-mile field trip was taken including; inspection of (1) the 200-megawatt, pulverized lignit-fired Leland Olds plant of Basin Electric Power Cooperative, under construction near Stanton, N. Dak.; (2) the site of the Glunharold mine of the Truax-Traer Coal Co., Division of Consolidation Coal Co., where a wheel excavator was being assembled; (3) the operating Beulah mine of Knife River Coal Mining Co., subsidiary of Montana-Dakota Utilities Co., near Beulah, N. Dak.; and (4) the 400-megawatt, hydroelectric Garrison Dam powerplant, near Garrison, N. Dak.

Jan 1, 1966

By Wm. Mark Hart

High horizontal stresses and shear failure have been considered the major reasons that cause entry roof failure and falls for underground mining. Therefore, reorientation of the current mining systems or layouts or using angular crosscuts in mains or gate entries becomes more popular if a greater than normal horizontal stress is measured. However, reorientation of the current mining systems or layouts is always expensive and use of the angular crosscuts may weaken the pillar structure at corners. Therefore, cautions must be taken before any decision related to reorientation of the current mining systems or layouts or use of angular crosscuts is going to be made. In order to prevent entry roof failure and falls, the following two issues must be carefully examined and fully understood: 1. Which one, shear stress or tensile stress, is going to be blamed for entry roof failure? 2. Which one, horizontal stress, vertical stress, or local geological weakness plays a major role in entry roof failure and falls? This paper analyzes the mechanisms of entry roof failure and falls for underground mining in general examines the roof fall history at Springvale Colliery, and proposes the means of preventing roof failure and controlling roof falls for Spingvale Colliery in particular.

Jan 1, 1996

By P. W. Godbehere

"INTRODUCTIONMagnetic mill linings have been developed from an invention by Mr. Bertil Brandt, the originator of the Skega rubber lining. The OREBED magnetic mill lining is a concept in which rubber covered strontium ferrite permanent magnets are arranged on the inside wall of a mill shell so that they attract magnetically susceptible material be it ore, media or tramp, to form a protective layer over the magnets and to serve as an operating surface with indefinite life.Noranda Mines Ltd. through its associate Norcast Division of Noranda Metal Industries formed a joint venture with the inventors to market magnetic mill linings in North America. For the past twelve months trials have been undertaken in conjunction with Orebed Inc. to test and develop these linings for grinding mill applications at the Horne Concentrator. Two independent milling circuits are currently being operated, one treating a siliceous gold ore and the other a copper slag.This paper presents the results of the magnetic lining test programme to date."

Jan 1, 1983

By Fernando Romero Lage

"Crushing and screening theory and application has remained fairly consistent in the last 50 years. The application of such equipment is guided by varied formulaic conventions and rules that due to the entropic nature of the process, remains more an art than a science. The variability of conditions creates an environment in which trial and error becomes the principal means of process balance and control. This paper illustrates some of the theories behind the process, plus other assumptions, postulates, myths and misconceptions that exist within the crushing and screening industry.INTRODUCTIONContinuous material balance calculations are habitually performed in the design of new comminution circuits as well as in the valuation of existing circuits. A continuous material balance calculation is one in which the input rate of material is equal to the output rate for each unit functioning in the circuit. At continuous analysis, there is no accumulation or losses of material within the system, as it is when performing a discrete event analysis.In order to produce viable and manageable mine-to-mill material, whether it is ready to leach or ready to mill, we must reduce the material in a series of stages. The power demand increases as the material size decreases, as it is when folding a piece of paper successively. As with the paper, there is a crushing size limitation that is a consequence of the mineral properties such as work index, moisture, viscoelasticity, etc. Comprehensive knowledge of crushing plants in both the aggregate and the mining industries show that, after three stages of crushing, a particle size distribution originating from a blasted deposit can be reduced from an nominal maximum size of 500 mm to a nominal maximum size of 12 mm. if the last stage of crushing is set in closed circuit, the screen openings will be able to yield a smaller top size.Achieving steady and continuous material balance poses major difficulties as crusher lose their settings, screens blind or peg, and material characteristics change geographically or seasonally. Overloading conditions in crushers and screens are nothing but counterproductive, and the net losses of an unbalanced circuit can be overlooked when mining operators are paying a lot more attention to the evermore complex systems downstream.It is not simply the crushing of the mineral but achieving the right size for the downstream milling process that will yield the maximum amount of energy savings."

Jan 1, 2010

By Z Li, A Fleming, S Webster, L Snyman

Northparkes Mines is developing the E26 Lift 1 North block cave mine, which is adjoined to the existing E26 cave. This paper presents the challenges and methods used to design the ground support system during the feasibility study. Calibrated numerical simulations were conducted to forecast the levels of rock mass damage and to assist the ground support design. Generally, low to moderate rock mass damage is forecast on the extraction and undercut levels. However, poor ground conditions are expected in sheared and preconditioned zones adjacent the existing E26 cave. This will result in difficult ground conditions during development, undercutting and drawbell establishment. Empirical assessments were conducted to make sure the ground support system is able to handle both the static and dynamic load demand, and to accommodate the deformation values. A safety factor of 1.5 was used for the designs to cover the unknown rock mass conditions and potential for larger seismic events. Learnings from the E26 Lift 1 and SLC, also mining against the E26 cave, are incorporated into the design. Fibrecrete, mesh and resin bolts / mechanical anchors are the primary ground support system used, and cable bolts for intersections with a span of more than 6 m. Following undercutting and during the operating life of the mine, secondary ground support and rehabilitation will be required.

Mar 15, 2021