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By R. Burkhard

Recovery of metals from complex mixed wastes is a challenging task of modem material and waste management strategies. Thermal methods are an important tool in this respect. Plasma turned out to be particularly useful for treatment of complex or toxic wastes and residuals. In order to study plasma processes at reasonable costs, a pilot plasma plant has been used and wastes like ~pent Raney-Nickel catalysts, copper and ah.:lminum drosses, and. other metal containing wastes were investigated. The paper summarizes the most significant findings

Jan 1, 1995

By W. K. Kleysteuber

This report covers the design and testing of a novel bulk materials conveying device by the Bureau of Mines. The transport concept of the device is to create a traveling wave with a steep front so that the bulk material slides and cascades down the front of the wave with some horizontal motion. Ideally, the front should act like a continuous chute. The concept of moving bulk materials along a belt without any forward movement of the belt itself was demonstrated. The conclusions reached were that the mechanism as designed could not overcome the inherent major disadvantages that would make the undulatory conveyor suitable for practical applications.

Jan 1, 1974

By K Hortin

Kidd Creek mine in north western Ontario is developing phase 1 of the deep mine project for mining between 2100 m and 3100 m below surface. Heat problems were experienced during the 2003 summer in working places about 2300 m below surface. At the time the mine had a æcold stopeÆ for cooling the air supplied to the mine below 1500 m from surface. The æcold stopeÆ is where during winter, ice is created in both the open pit and its connecting airways to the mine and used to cool air in summer. The operation and limitations of the existing cold stope were evaluated and led to the requirement for additional mechanical cooling to be available for the summer of 2004. The first stage of a surface refrigeration plant providing 7.5 MWR of cooling was approved, the compressor set was ordered in early January 2004 and the plant commissioned six months later in early July 2004. Based on the current modifications to the mining plan, further plant expansions are required in 2006 and 2009 leading to a total of 19 MWR of mechanical refrigeration and 8.5 MWR equivalent from the extended cold stope. The refrigeration system is described with emphasis on the specific adaptations necessary to suit Canadian conditions. Additional investigations were; using the refrigeration compressors in winter for heating and, extending the performance of either cold stopes or alternative ice storage systems. The winter use of refrigeration involve removing heat from the mine exhaust air to provide a cooling load and to use the hot water in the condensing circuit to heat the intake air and reduce reliance on mine air heating with natural gas. This paper follows on from an earlier one presented at the Seventh International Mine Ventilation Congress where the background and planning of the mine ventilation and cooling requirements were described for extending the mine at depth to 3100 m.

Jan 1, 2005

By Marsh A. Cooper

THE THEME of my remarks provides a great deal of latitude. I shall therefore take advantage of the scope it offers to look at our industry across a broad spectrum. My observations reflect a Canadian mining man's varied career as a geologist, mine operator, geological consult ant and company executive in Canada and overseas ... under differing cultures, business environments and political jurisdictions. I was fortunate to come into this industry in the mid-1930's when it was characterized by great enthusiasm, drive and resourcefulness. It was the beginning of a burgeoning era of some 30 years' duration in which the individualist, the entrepreneur and the builder found ample room for expression. As I contemplate the environment in which we now have to operate and try to perceive what lies ahead, I find myself deeply disturbed. Something serious has happened to this industry along the way. It appears that our very success has been the source of our undoing. I believe it is useful to summarize our industry's basic strength at home as a take-off point f or assessing its position in world terms. I hope that I can focus on some of the things that, in my view, must be done for this industry and by this industry to restore Canada's historic role in the world mining community. The Canadian mineral industry provides 140,000 jobs. It pays the second -highest average weekly wages and salaries among the country's major industries. The output per employee in the mining industry is estimated at about three times that for the economy as a whole.

Jan 1, 1977

By H. N. Maleki

Tension-torque relationships were investigated *n a coal mine for bath standard 5/8 in. (16 mm) bolts and a vibrating wire instrumented bolt, using conventional and controlled installation techniques. The instrumented bolts differed from the standard bolts by their head size and hole preparation procedures. The controlled installation technique developed by the U. S. Bureau of Nines (USBN) involved using hardened washers and lubrication in the bolt assembly, and maintaining a minimum thrust level during bolt installations. The object of this study was to determine the tension to torque ratio (lb/ft-lbs; for standard bolts and instrumented bolts for both conventional and controlled installation techniques, and to modify the bolt assembly so that the ratios would be equal for the instrumented and standard bolts for both installation techniques. It was shown that the instrumented bolts installed in faced holes had a similar tension torque ratio td that of standard 5/8 in. (16 mm) bolts installed in unfaced holes for each installation technique, and thus they were representative of other uninstrumentea bolts. This was achieved by evaluating the influence of several factors oh the relationship, including: facing the hale surface, introducing washers and lubrication in the bolt assembly, and applying different levels of thrust at installation due to bolter operator practice. The tension to torque ratio fur conventional bolts was only 21 (lb/ft-lb) for the coal mine, resulting in an installation tension of 4000 lbs (17.8 kg) with the typical installation torque of 150 to 400 ft-lb. This tension level was approximately 50 percent of the required bolt tension, and thus, it was concluded that torque standards are not sufficient to assure adequate bolt tension. .he low tension levels were due to the particular wait hardware in use, operator practice, and bolt fencing.

Jan 1, 1984

By Dave D. Ferris

Today the coal industry is beginning to use some very fundamental economic evaluations to determine the most economical circuit to produce a specified saleable product. The fundamental economic methods used are standard return on investment and net present value calculations. By utilizing these economical evaluations, one can justify a larger capital expenditure and realize more return for an investment over the life of a coal property.

Jan 1, 1983

By E. Miller, J. M. Eldridge, K. L. Komarek

The liquidus curve of the Mg-Pb system was accurately redetermined. The compound Mg2Pb decomposes peritectically at 538.2° ± 0.3°C to liquid and to a compound p' which melts congruently at 35.0 at. pct Pb and 549.0° ± 0.3°C. The solidus curve of ß' was determined. X-ray diffraction studies indicate that 4' has an orthorhombic structure. Activity values of magnesium calculated from the phase diagram agree with those published in the literature. EXPERIMENTAL thermodynamic properties of binary metallic systems have to be consistent with values calculated from the phase diagram. In systems forming intermetallic compounds the shape of the liquidus curve near a compound is determined by the thermodynamic properties of the coexisting solid and liquid phases. Hauffe and Wagner' neglected the temperature dependence of the chemical potentials and obtained the potential differences of the components of the liquid alloys, relative to stoichiometric liquid. Their calculations were based on the liquidus curve and on the heat of fusion of the compound, and were only valid near the congruent melting point. Steiner, Miller, and Komarek2 developed equations which account for the temperature dependence and obtained the chemical potentials of liquid Mg-Sn alloys over the entire phase diagram from the liquidus and solidus curves and from enthalpy values with the pure components as the standard states. The Mg-Pb phase diagram has been studied by several investigators whose results have been compiled and critically evaluated by Hansen.3 Although the liquidus curve was poorly defined, the general features of the diagram, i.e., one congruent melting compound, Mg2Pb, of essentially stoichiometric composition, two eutectics, and limited terminal solid solubilities, seemed to be suitable for a similar thermodynamic analysis. A careful redeter-mination of the liquidus by thermal analysis revealed, however, the existence of another compound. The liquidus curve between the two eutectics was precisely delineated and the structure and solidus curve of the new compound were investigated. The revised phase diagram was thermodynamic ally analyzed to evaluate the activity of magnesium in the liquid alloys. EXPERIMENTAL PROCEDURE The magnesium metal (Dominion Magnesium Ltd., Toronto, Canada) had a purity of 99.99+ pct; lead (American Smelting and Refining Co.) contained 99.999 pct Pb. Most experiments were carried out in graphite crucibles. Several experiments were made in high-purity alumina (Triangle R.R., Mor-ganite, Inc.) and in Armco iron crucibles to test the inertness of the graphite crucibles. Chemical analysis of magnesium and detailed description of the procedure for thermal analysis have been given previously. For the determination of the solidus curve of the compounds, specimens of initial composition Mg2Pb were equilibrated in a closed isothermal system with magnesium vapor. The source of the magnesium vapor was an alloy which had a gross composition lying in the 0' + L field at the temperature of equilibration. As equilibrium was approached, the specimens lost magnesium to the two-phase reservoir thereby lowering the activity of magnesium in the specimens until activity and composition equaled that of the ß'/ß' + L boundary. Crucibles (1.9 cm ID by 2.2 cm OD by 4.1 cm high) and tightly fitting lids were machined from a molybdenum rod; small, shallow trays were fashioned from thin (0.005 in.) molybdenum sheet, and all the molybdenum components were degreased in hot carbon tetrachloride and then dried. The pieces were then degassed in vacuum at 950°C for about 6 hr. The two-phase alloy was placed at the bottom of the crucible and small specimens of the Mg2Pb compound, weighed on an analytical balance, were placed in two molybdenum trays above the two-phase alloy. The crucible was closed by forcing its lid on and then inserted in a titanium crucible. This crucible was evacuated, flushed twice with argon, and welded under argon. The specimens were equilibrated for about 1 week in a resistance furnace regulated by a Celectray controller, and the runs were terminated by water quenching. The specimens were again weighed and the equilibrium compositions were calculated on the basis that the weight losses were solely due to a loss of magnesium to the two-phase alloy. The structure of the B' phase was investigated by the Debye-Scherrer X-ray diffraction technique. Selected ingots from thermal-analysis experiments containing about 35 at. pct Pb were re-melted, slowly cooled, and crushed in an argon-filled glovebox until the entire ingot passed through a 50-mesh sieve. The powder was thoroughly

Jan 1, 1965

By Eric Reale

The New York City Department of Environmental Protection (DEP) is currently building City Water Tunnel #3 beneath the city. The purpose of this tunnel is to improve water distribution to the city and to allow the DEP to inspect the older tunnels and make the necessary repairs. These older tunnels have been in continuous operation since the early 1900's. Construction on the Third Tunnel is planned in four stages. The Nelson Street Shaft, which is the focus of this paper, is part of the second stage.

Jan 1, 1989

By Klaus M. Hahn, Kurt Aasly, Jutta Lennartz, Hermann Wotruba, Ben Snook, Przemyslaw B. Kowalczuk, Rolf Arne Kleiv

"Seafloor massive sulphide (SMS) deposits have been identified as important marine metal resources for the future. However, literature on mineral processing of SMS is currently limited, and to date, no research has been published on processing of SMS from either active or inactive hydrothermal vent fields on the Arctic Mid-Ocean Ridge. In this paper, individual SMS rock samples from the Loki’s Castle area were tested. Chalcopyrite, isocubanite and sphalerite represented the main copper and zinc bearing minerals in the SMS samples, whereas the gangue consisted of barite and silica. Based on the X-ray transmission response (XRT), i.e. differences in the atomic number of elements in tested samples, and using portable XRF (PXRF) values of elemental composition, individual particles were classified as a either product (low barium / high to low silicon / high copper and zinc) or waste (high barium / high silicon / low copper and zinc). The classification was based on the elemental composition of the samples with the cut-off grade equal to 0.5% for copper. It was shown that the XRT discrimination analysis correlated well with elemental (PXRF) data classification. The results clearly indicate that X-ray transmission sensor-based sorting can be used a useful technique for preconcentration of SMS rock samples. INTRODUCTION Due to different compositions of investigated samples, sensor-based sorting is a useful technique for preconcentration of different materials. The aim of using sensor-based sorting is to upgrade an ore by reducing the quantity of overall waste material reporting to the next processing stage. This can be achieved by eliminating (reducing) the waste fraction. By applying sensor-based sorting, the energy consumption for particle comminution as well as the required process water and reagents can be decreased. The total volume of the waste rejection leads to a proportional reduction in the total energy costs (Lessard et al., 2014, 2016)."

Jan 1, 2018

By R. Dell Davidson

This report contains the results of the work performed by Dayton T. Brown. Inc., Testing Laboratories, Bohemia, New York, under the Department of Interior, Bureau of Mines, Contract J0166089 entitled "Performance Testing of Air-Line Linking Components." The objectives of the program consisted of the following: 1. To conduct engineering tests that will provide data to recommend the performance criteria for air hose and piping connections. 2. To determine the requirements for restraining devices which are used to comply with MESA Health and Safety Standards 55, 56, 57,13-21.

Jan 1, 1978

By Ross D. Lawrence

"IntroductionOne of the methods used when applying the Market Approach to the valuation of a mineral exploration property is known as the Joint Venture Terms Method. The method is particularly useful for the valuation of early-stage exploration properties. Unfortunately, valuators are sometimes imprecise in distinguishing between joint ventures and other types of transactions.At VALMIN '94, Bob Appleyard1 proposed that, if one ignores the time value of money and the probability that the expenditure commitment would be completed, the formula to calculate the value ($V) of a property owned by Party B at the time of the deal would be:$V =$Ex (100-1%)/1% (Formula I)Where $V is the value of the property2Where $E is the expenditure commitment by Party A, andWhere 1% is the percentage property interest to be earned by party A.At PACRIM '99, Mike Lawrence and Graham Dewar3 referred to this method and suggested that there was an ambiguity in the formula proposed by Appleyard in 1994. Mike Lawrence referred to this problem again at VALMIN '014•Lawrence & Dewar suggested that the formulashould be:$V100% =($Ell%) x 100 (Formula 2)Where $V 100% is the value of the entire property,Where $E is the expenditure commitment by Party B, andWhere 1% is the percentage property interest to be earned by Party B.Subsequently, there has been considerable discussion in the AuslMM Bulletin5. In my view, this discussion has touched on a number of useful points, but generally has overlooked one essential element needed for an understanding of the correct application of the N Terms method. That essential element is to understand that there is a material difference between (1) entering into a joint venture arrangement and (2) the purchase of an interest in a property."

Jan 1, 2003

By Donald B. Gillies

PROBABLY the most critical and difficult period in an engineer's career is that between the completion of his college work and his attainment of professional recognition and accepted status in the industrial world. Upon leaving school the young graduate breaks his immediate ties with his educational institution and in a sense finds himself adrift. At this time in his life a society like our Institute has both the responsibility and the privilege of meeting a vitally important need in his professional life. Some of these young men are Student Associates, in the year after graduation, and some are Junior Members, but all need advice and assistance. In some respects this situation will be accentuated by the war. Not only will thousands of young engineers be mustered out of military service but the process we describe generally as industrial reconversion will make necessary many readjustments in personnel. About two years ago the Institute recognized the opportunity of helping the younger member to help himself by appointing a new standing committee to be known as the Committee on Professional Development of Junior Engineers. Herbert Hoover is Honorary Chairman and it is my privilege to serve as Chairman. The name of the Committee is not entirely satisfactory but it expresses the general objective. The present article is in the nature of a progress report of the work of this Committee.

Jan 1, 1945

By M Danišík

Two drill core samples of haematite/goethite from the Robe River (Western Australia) channel iron ore deposits (CID) were dated using (U-Th)/He methods in order to constrain the timing of iron oxide formation and thereby provide a temporal context for CID genesis. (U-Th)/He ages (He ages) from these samples range from the late Oligocene to Late Miocene and despite a high degree of scatter, they corroborate relationships expected from the internal ooidal stratigraphy: For individual ooids, the ages from haematitic core are older than or indistinguishable from the ages of the surrounding goethitic cortex. The goethitic cortices are, in turn, older than the ferruginised wood fragments recovered from the cementing goethitic matrix.The data suggest the following succession of ore formation phases:• Haematitic cores in ooids of both samples formed in the Early to Middle Miocene.• Goethitic cortices of both samples formed in the late Middle to early Late Miocene. This appears to be the age of goethite cortex formation regardless of depth in the core, which does not support the top-down infill model, genetic model proposed by Heim et al (2006).• Wood fragments form a prominent component of the matrix and were ferruginised during the Late Miocene. Thus the data suggest that the unique environmental conditions for the CID formation existed during the Miocene.A methodological implication of this study is that the temperature utilised for He-extraction from iron oxides has a critical impact on the mobility of parent nuclides. The typical ~1100°C laser heating used for crystalline minerals like apatite or zircon induces loss of U and Th and results in erroneously old ages.

Jul 11, 2011

In todayÆs evolving and globalised world, mining companies are being pressured to move beyond compliance towards long-term sustainability and sustainable development. Companies are expected to æengageÆ communities and measure the success of these engagements without a clear understanding of æhowÆ to do this. This move, away from compliance, develops more of a focus on sustainability and æcommunityÆ social responsibility rather than corporate social responsibility. This shift leads to the development of world-class projects that provide sustainable development for people, reduce the incidence of costly delays, and promote good global citizenship for companies. The process of æengagingÆ communities in mining project design and development leads to sustainable development, a stronger license to operate, and a reduction in social and political risk. To create this mutually beneficial relationship between communities and companies, communities must be æengagedÆ in the project development and risk assessment processes as early as possible, preferably during the exploration or the concept phases. How to create this æengagementÆ and manage this risk will be discussed.

Jan 1, 2007

By S. A. Davis

In July of 1996, the Kroll process began production again at TIMET's Henderson, NV, manufacturing facility. This, after being shut down for several years due to low market demand for titanium. Faced with limited pond capacity and increasing costs for water and wastewater disposal and storage; process changes were made to recycle water used to wash Kroll titanium sponge back into the sponge leaching process. This idea was revisited from 1992-93, when three consecutive attempts to recycle water for this application were unsuccessful due to early pump failure. Since it was uncertain why previous attempts failed, a complete understanding of the existing system was first sought. This included reviewing piping and flow diagrams; taking field measurements for all the piping, valves, and fittings; analyzing the wastewater composition; and modeling the fluid dynamics and control of the system. The fluid dynamics of the system were modeled by breaking the piping network up into nodes and applying the Bernoulli equation to each segment. The fluid flowrate control valves were modeled for this purpose also and the models were used to help specify the required processing equipment and control ranges and tolerances. Once the project was completed, an operating procedure was prepared for operation, startup, and shutdown of the washer water recycle system.

Jan 1, 1999

By C. H. Grant

The Dew Chemical Company has been engaged in explosives research since 1953. The incentive for this research was based on the desire to find additional markets and uses for magnesium metal of which Dow is a heavy producer. The thermodynamic calculations for explosives incorporating light metals indicate energies approximately twice that of non-metallized explosives currently being used. Early in 1960, we acquired additional patent rights from independent inventors and decided to set up a development station at Virginia, Minnesota, to conduct a commercial testing and market evaluation program with this new product. The actual manufacturing of the explosive was to take place in the bore holes. Due to the complexities involved in controlling the manufacture of the explosive in the bore hole, performance was sometimes in doubt. Furthermore, our experience indicated that the metallized explosive systems could not be evaluated by the standard laboratory methods then being used, and it was necessary for us to look for more suitable research methods. Tests were conducted on several known methods for explosive evaluation. The most promising were the Navy underwater method for energy evaluation, and a modified Livingston crater method intended to compare explosive performance in rock. After shooting over two thousand charges of eight to 60 pounds under water and in taconites and granites with many types of explosives, we have developed a metallized explosive which is now being manufactured at a pilot plant in Virginia, Minnesota, and is being evaluated commercially.

Jan 1, 1963

By Z. F. Lodhi, J. H. W. De Wit, H. A. Terry

Zinc and its alloys have been extensively used as replacements for Cadmium coatings in aeronautical and automobile industries. Zn alloys with low Co or Fe have been highly investigated but coatings with higher amount of Co are very difficult to achieve due to anomalism associated with these coatings. Anomalous Zn-Co-Fe alloy is a relatively recent addition to the family of Zn alloys. It is found that the addition of Fe in the electrolyte assist in overcoming the anomalism. In this research Zn-Co-Fe alloys especially with higher amount of Co (>15%) and Fe (~1%) are investigated, after overcoming the anomalism associated with its deposition, and the corrosion resistance is compared with pure Zn and Cd. It is found that an increase in Co to higher than 25 % accounts for a shift in the OCP to a level near Cd yet keeps it electronegative to steel. The coating shows superior corrosion resistance, in terms of its sacrificial and barrier properties in 3.5% NaC1 as compared to Zn and Cd.

Jan 1, 2006

By Ian Sherrell, Christian Cardoso, Henri Vepsäläinen, Guillermo Bermudez

Performance of mixing mechanisms in flotation cells is paramount, as inefficiencies can lead to financial losses through valuable minerals lost to tailings. Technological advancements have been implemented in flotation cells to optimize performance, but regardless of the efficacy of these developments, room for improvement may persist. Since its launch in 2005, FloatForce® has set a high industry standard for flotation mixing mechanisms. However, current mining trends call for sustainability-driven developments while improving metallurgical performance. Metso has recently introduced FloatForce®+, the latest iteration of FloatForce, developed through extensive laboratory, pilot, and industrial testing, aligning with mining sustainability trends. It has been designed to maximize recovery, reduce power draw and optimize manufacturing materials. This development stems from a redesigned rotor profile paired with a harmonizing stator configuration. This paper presents the development journey of Metso’s latest patented flotation mixing mechanism, an advancement to improve metallurgical performance at a high sustainable standard in flotation cells. The theory, CFD modeling and test work are discussed in detail.

Feb 1, 2025

By B. D. Rayment, J. D. Wilson, G. R. Davis

Wheal Jane, situated between Truro and the Carnmenellis granite, is under development by Consolidated Gold Fields, Ltd., as a tin producer. The main or B lode comprises a complex cassiterite-sulphide ore located in shear zones along the footwall of the lowest of a series of porphyry dykes (elvans) which strike ENE and dip 35° north. Minor mineralisation follows other elvan contacts and sets of later steeply dipping fractures. The localisation and overall geometry of the deposit is explained in terms of the complex structural geology of the Lower Palaeozoic metasediments and the shape and manner of emplacement of the invading Hercynian granite of Cornwall. Variations in the thickness and grade of the orebody, and in the nature of the mineralisation, are shown to be structurally controlled by undulations of the footwall contact of the B elvan. Wallrock sericitisation is present and is applied in exploration for ore

Dec 1, 1971

By S. Banisi, Seyyed Omid Mousavi, Alireza Ghasemi

Discrete Element Method (DEM) is extensively used to simulate the behaviour of particles in various processing units. This method is based on modelling the forces acting between particles in any contact and consequently calculating the new position of particles. The high number of elements and numerous equations needed have made the required computation time very long even using computers with very fast processors. The required computation time mainly depends on the time step. If the time step is chosen very short, the computation time will significantly increase. On the other hand, if the time step is chosen very long, the simulation will be in error due to not fully observing the contacts. In DEM calculations, the time step is chosen as a fraction of the collision time. In this research, a relationship was proposed between the contact time fraction and the error of simulation. In other words, to select the time step in addition to physical parameters, the accuracy of the simulation was also accommodated in the frequently-used relationships. The simulation error was defined as the relative difference between the initial restitution coefficient and the restitution coefficient obtained after simulation. The required time steps to arrive at the simulation error of 5% were calculated for two common contact force models namely, Hertz-Mindlin and linear spring-dashpot. The simulation was performed for two particles with radius of 3 cm, elasticity modulus of 210 GPa, Poisson's ratio of 0.3 and relative velocity of 0.5 m/s. The required time steps were found to be 2.3 and 0.19 µs for the Hertz-Mindlin and the linear spring-dashpot contact force models, respectively. Results showed that with a scaling-down the modulus from 210 GPa to 2.1 MPa, the required time steps for the Hertz-Mindlin and the linear spring-dashpot contact force models, with an equal simulation error, increased by 100 and 316 times, respectively.

Jan 1, 2014