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By M. S. Moats

The treatment of oxidized residues of zinc with high iron content continues to present a technical challenge in both the steel and zinc industries. Two main problems are commonly identified and include high treatment costs and environmental concerns about contaminated, iron-bearing residuals. A new approach to this problem is described in which selective separation of the iron and zinc into salable products may be potentially feasible. The waste material is first leached to give a solution having an approximate concentration of 110 g/l Zn, 15 g/1 Fe and 40 g/1 H2SO4 and other impurities such as Pb, Cd, Cu and Sb. A suitable organic, such as D2EHPA, is used to load the majority of the iron. The aqueous phase is then acceptable for zinc electrowinning after standard solution purification. The novel step in the flow sheet is the efficient recovery of the ferric iron from the organic solvent using a solid metal to reduce the iron to the ferrous state. The Fe+2 is easily stripped into an aqueous phase in a relatively pure form, suitable for use in water treatment. Process parameters and possible flow sheet designs are described and discussed.

Jan 1, 1995

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

T. L. Joseph (University of Minnesota, Minneapolis, Minn.)—Mr. Killian is to be commended for his inquiry as to why a decrease of 15.3 pct in coke consumption was accompanied by a decrease of only 1.9 pct in the CO/CO, ratio of the top gas. Although I encouraged him in his efforts to find a more significant and meaningful carbon-gas ratio, the method, calculations, and conclusions originated entirely with the author. Whether we agree entirely with the assumptions underlying his corrected ratio, I think we can all agree that a better ratio is needed, and that he deserves credit for recognizing the need and for doing something about it. To be most useful, the CO/CO, ratio for the top gas should reflect the way in which the carbon is gasified in the furnace, particularly the degree of oxidation and the extent of heat release. The effect of CO, from the decomposition of the limestone and the effect of the reaction of CO and water vapor in the upper part of the furnace on the quality of top gas should be isolated from the effect of more basic reactions such as ore reduction and solution loss. The reduction of sufficient iron oxide to produce a ton of pig iron and the accompanying changes in the proportions of the carbon gases can be expressed on a mol basis as follows: 16.5FeA + 16.5CO - 33FeO + 16.5CO, [1] 33FeO + 33.0CO = 33Fe + 33CO. [2] The CO, from eq 1 normally escapes from the furnace because it does not react with coke at the temperature of its release. However, as much as 50 pct of the CO, from eq 2 may react with coke because it is released at temperatures above 1000°C: 16.5CO. + 16.5CO2 = 33CO [3] Thus we see that the gasification of 16.5 mols or about 200 lb of C in solution loss will regenerate as much CO as is required for the last stage of reduction. The pronounced effect of reaction 3 on the final proportions of CO and CO, in the gas stream is obvious. It also follows that reaction 3 materially alters the heat release but it cannot be entirely eliminated in Lake ore practice. A previous study indicates that 100 lb of solution loss may be necessary to maintain the reducing power of the gas. A reduction of 100 lb from the normal level of 200 lb would mean that over 1,-000,000 additional Btu are released in the process. The 100 lb of additional carbon which will be burned at the tuyeres will release 437,000 Btu and the absorption of 583,000 Btu by eq 3 would be prevented. One of the chief objectives of sized ore burdens and more uniform distribution of the gas stream is to minimize solution loss by completing reduction higher in the furnace and in turn to release the maximum amount of heat from the carbon charged. It was odd, indeed, to find that the use of sized ore and sinter in the careful tests reported by Dobscha had changed the CO/CO2 ratio very little. The author has stressed the close correlation between his corrected CO/CO, ratio and production. A correlation of fuel consumption and the CO/CO, might be more logical. Fuel consumption on the prepared ore burden decreased 15.3 pct whereas the corrected CO/CO2 ratio decreased 19.0 pct. Although this agreement between the reduction in fuel and the reduction in corrected CO/CO2 ratio is not as close as the correlation with tonnage, it indicates the corrected ratio is superior to the normal ratio which decreased less than 4 pct. Some adjustment should be made for the reaction: CO + H2O = CO2 + H2 —700Btu [41 because there is evidence to indicate that about one half of the hydrogen is formed in the upper 21 ft of

Jan 1, 1953

By W. L. Jiang

Reverse-flotation technology is often applied in iron ore dressing plant, in order to enhance the quality of iron concentrate from magnetic separation. However, this technology has disadvantages in operating cost, energy consumption, and environmental protection. Developing innovative equipment to process magnetite ore more-effectively is a way to get rid of these disadvantages of reverse flotation and improve the quality of iron concentrate. This paper describes the development of Complex Flashing-Field Magnetic Cleaner, a new kind of equipment based on the principle of combination of separation in magnetic field and separation in gravity field. This innovative equipment possesses a tailor-made magnetic system and has the characteristics of a magnetic field, which can strengthen the formation of magnetic agglomerations and the dispersion of gangue minerals, improving the quality of separation. The automatic control system developed specifically for this equipment can further increase the accuracy of separation and stabilize the process. Test results showed that this equipment is reliable in operation, economically beneficial, and has large potential of application.

Jan 1, 2014

By P. Kim Carroll, D. Nick Tiffany, Doyl M. Fritz

Thunder Basin Coal Company received the 1987 Wyoming Excellence in Surface Mining Award for construction of the State's first major sediment control reservoir to be designed using the new settleable sol ids standard. Use of this standard resulted in construction cost savings of more than $250,000; reduced water quality monitoring; enhanced downstream channel stability because of more natural sediment loading; allowed simultaneous establishment of permanent waterfowl and fisheries habitat; and provided a quality recreational site. This article will address factors associated with the design and construction of that sediment reservoir and the benefits that were realized. (Note: This paper was originally published in the proceedings for the 1988 National Symposium on Mining, Hydro1ogy, Sedimentology and Reclamation held in Reno, Nevada, December 5-9, 1988.)

Jan 1, 1989

Caterpillar unveiled a new dozer, the new Cat D10T2 dozer, that builds on the success the company has had with its D10T model. The newest version of the dozer includes refinements to its power train, automated controls and structures. The result, the company said, is high productivity with superior fuel efficiency, reliable operation with long-lived structures, as well as enhanced access for service technicians and operators. The D10T2 uses the latest load-sensing hydraulics technology combined with Cat advanced engine controls to maximize the amount of material moved for every drop of fuel burned. Improved filtration protects the fuel system, hydraulic system and power train oil system to help ensure high reliability and minimal machine downtime. Refined large structures, such as redesigned track roller frames, deliver longer service before rebuilds. Improved access and egress features enhance safety and productivity of technicians and operators, and optional powered access systems and platforms enable configuring the D10T2 for the site. Caterpillar offers the D10T2 with two variations of the Cat C27 engine with ACERT Technology. One version is U.S. Environmental Protection Agency (EPA) Tier 4 Final certified, and the other is capable of achieving emission levels equivalent to EPA Tier 2 standards. Both engine configurations produce net power of 447 kW (600 hp) in forward gears and 538 kW (722 hp) in reverse gears. The engine controller automatically adjusts power output based on the direction of travel. With the new system, the D10T2 has about 20 percent more power in reverse compared to its predecessor model. The result is faster cycle times and greater productivity in certain applications. The D10T2 is suited for a variety of applications including mining, heavy construction and bulk materials handling.

Mar 1, 2014

By Claudia Castillo, Katja Freitag, Jan Cilliers, Diana Drinkwater, Robert Seitz

The talent gap in mining is not a new challenge. Mining companies continue to seek innovative ways to attract, develop and retain talent, and younger workers are looking for opportunities to develop their professional careers. Training provides a key value proposition for both employees and employers as it helps build a talent pipeline while offering opportunities for learning and growth and value creation. In 2020, Metcelerate launched its 20-month program for early career mineral processing engineers. The program helps develop critical technical skills in the workplace and is a tool to identify motivated engineers and change culture within teams. Learners cap their skills development by executing a technical investigation. This generates immediate value—a win-win outcome for learner and company.

Feb 1, 2025

By C. Turek, R. Henderson

Mine planning is the foundation of value for a mining company. Good mine planning requires solid understanding of the ore body, rigorous standards and processes, robust and useful information technology and skilled people. Life of mine planning is key to identifying strategic direction for any mine and short range mine planning is key to delivering forecast and budget expectations. Mine planning at Kinross has been identified as a critical success factor and initiatives are being prepared to improve the quality of our plans and to build bench strength in our teams. The Kinross Way for Mine Planning (KWMP) has been developed and implemented to establish the standards to ensure a strong business foundation. This paper briefly describes the process used to develop the KWMP and presents a selection of mine planning best practice initiatives at Kinross mines.

Jan 1, 2011

By K. R. Nichol

The author points out that corrosion works 24 hours a day, every day. It is an economic reality that the cost of corrosion is inevitable and that its cost should be incurred in the least expensive way. An economic evaluation technique to properly assess its relative impact is the Discounted Cash Flow Method. Various remedial and corrosion control measures are available and these, when coupled with a planned corrosion control program, help reduce the cost of corrosion.

Jan 1, 1973

By T. W. White

One of the objectives of today's mine superintendent is to increase his equipment availability. To this end we have seen improved scheduling procedures, preventive maintenance programs and extensive drive training and operating procedures. However, until recently, one area that has changed little in the past twenty years is the method of refueling and servicing mine equipment. In looking at mines across the country continually one encounters the hazardous oil soaked ground, the hand held fuel nozzle and the maze of hoses of the "traditional" fuel stop. By adapting technology developed in the construction and aircraft industry, current fueling and servicing practices can be easily improved. The result will be less nonproductive time, less downtime from engine failures and increased security from major refueling fires. The time saved almost amounts to having another truck in the fleet! One feature of the improved servicing practice is the implementation of high flow fueling. For trucks now on the market, a flow rate between 120 and 150 gam is feasible, about 90 gam greater than current practice. This flow rate could be increased even further as larger trucks come into use. A second idea borrowed from the aircraft industry is the use of positive lock type connection nozzles that automatically shut off when flow stops. These may be used for fuel, water, oil and hydraulic systems to eliminate spillage and assure that clean fuel, oils, and water are delivered to the vehicles. The reduction of fuel spillage lessens the threat of major fires resulting: in equipment damage and loss. Eliminating fire hazards will become even more important as the turbine engine with its lighter, more volatile fuels come into common use.

Jan 1, 1972

By H. C. LIVINGSTON

At the Hanna No. 4-A mine of The Union Pacific Coal Co. a new system of trackless mining is being utilized to extract a 26-ft coal seam. By using shuttle cars and a conveyor belt for haulage in the rooms and panel entries instead of pit cars and panel hoist a saving of 12 cents per ton is expected. Mining is conducted in a 26-ft coal seam laid down on a synclinal structure with active workings on a pitch of approximately ten to twelve degrees. The coal seam is interbedded between a shale bottom and sand- stone top. The coal is friable, high in moisture, and subject to spontaneous combustion. The mine is rated gassy by the State Coal Mine Inspection Department. Mining is conducted at the present time by unbalanced rope haulage an main slopes spaced on approximate 4300-ft centers with the three-entry system driven to boundary lines, strike entries being turned on approximate 1300-ft centers. Panels are driven to the rise between entries at approximately 750-ft intervals with panel rooms driven on the strike 500 to 600 ft long, leaving 150 ft of barrier pillar between each block of panel rooms.

Jan 1, 1949

By George H. Found

During recent years considerable interest has been focused on the energy-absorption characteristics of metal when it is cyclically stressed in vibration. The most familiar manifestation of this phenomenon, which is called the "damping capacity" or "internal friction" 06 a material, is involved in the dissipation of mechanical energy of vibration, which otherwise would build up to stress levels where the problems of noise and fatigue are involved. In addition to its engineering importance in structures, the damping behavior of metals, particularly at low stress amplitudes, has also been used as a unique metallurgical research tool with which to provide sensitive means for indicating certain structural changes within metals. Important contributions toward understanding the energy-dissipating -mecha-nisms that are responsible for internal friction in metals have been made in the last few years. The information is not yet sufficiently extensive, however, to provide a useful metallurgical concept describing exactly how the structure affects the internal friction, or to encourage more general use of this technique among metallurgists. Three fundamental mechanisms have been proposed, as a result of recent experi- mental investigations, to account for the internal friction in nonferrous metals in low-stress amplitude tests. These include damping due to internal thermal currents that are created and flow in metal because of differential vibratory stress effects,' damping due to localized inelastic stress relaxation at inhomogeneities within the meta1,2,3 and damping related to plastic flow of a localized type for which an explanation has been sought in terms of the dislocation theory.' How each of these mechanisms functions as a result of structural changes in the metal is, in general, not well understood because of insufficient experimental data for which the controlling variables ham been segregated and because of uncertainties in regard to the nature of the structural changes themselves. In several investigations the effects of cold-working on the internal friction of polycrystalline brass and aluminum have been described. As reported by Köster and Rosenthal,5 and by Förster and Breitfield,6 there is an initial large increase in the damping when the metal is worked. The initial high value is not stable, but declines rapidly, at first, in a hyperbolic manner. About Ioo hr. after straining, a stable value is reached of magnitude proportional to the amount of strain.' In Fig. I is shown the relationship found by Zener and his collaborators between the internal friction due to cold-working of alpha brass and the amount of cold-working.8 Several investigators have made internal-friction measurements on worked poly-

Jan 1, 1945

By J. H. Zietsman, M. W. Erwee, Q. G. Reynolds

Pyrometallurgical furnaces, essential for metal extraction, operate at temperatures exceeding 1600°C and represent complex multiphase systems that challenge direct industrial research. Multiphysics models play a key role in shedding light on their intricate behaviours, supporting the refinement of design and operational strategies. Integral to the operation are the tap-holes, which facilitate the removal of molten products and are routinely opened by lancing, a process comparable to the use of a cutting torch, where high temperatures result from oxygen reacting with an iron lance. When the lance pierces the clay, oxygen gas enters the furnace, which could influence the behaviour of the molten material inside. In this work, a multiphase fluid flow model was used to investigate bulk flow dynamics, with a focus on the effects of the lancing process on the inside of the furnace, immediately behind the tap-hole. Incompressible and compressible multiphase fluid solvers were used and compared with respect their performance – the intention was to assess whether using a compressible solver would yield a different solution to the incompressible one. It was concluded that there are negligible disparities in bulk fluid flow behaviour between the solvers for the case studies examined, indicating that solver selection might be less consequential for certain aspects of oxygen lancing.

Apr 16, 2024

By A. Mosqueda Martinez, L. C. Trytten, R. P. Kofluk, J. J. Budac

The Corefco ammonia leach nickel refinery treats Ni-Co mixed sulphides from the high-pressure acid leaching of Moa Bay nickel laterite. Due to the low iron content of the feed, the ammonia leach process generates a leach residue with ~10% Ni+Co. Since commissioning a leach residue pressure filtration circuit in 2002, this residue has been stockpiled, dried, and sold commercially. For several years, the residue was sold to nickel smelters overseas. In 2014, re-processing of the residue in the high-pressure acid leach was tested. Lab test work was completed showing excellent extraction of the contained nickel and cobalt, and additional beneficial effects in the high-pressure acid leach circuit. A plant test in Moa confirmed the results, and preparation for shipment of the valuable leach residue for re-processing has begun. This paper outlines the test work and results, and some commercial considerations.

Jan 1, 2015

By F. Ansheng

Though it becomes increasingly important with the valuable minerals in their deposits tending to be fine and poor, the solid and liquid separation remains difficult especially when the particles are of micrometer size and of low density. Almost of all conventional thickeners result in that fine particles lose into overflows which often costitutes a loss of potentially valuable resources as well as an environmental hazard. The addition of flocculations may improve the settling of solids but may also not work well for the final removal of fine particles from the overflows (Ref.1).

Jan 1, 1990

The present study is devoted to improvement of the leaching efficiency during phosphorous removal from high phosphorous gravity-magnetic concentrate. Before leaching the concentrate has been subjected to roasting with the addition of either Ca(OH)2 or CaO. The oolitic iron ore is roasted at 900°C for one hour. This reflects in reaction between alkaline earth additive and quartz, aluminosilicates, phosphorus, and some other minor components of the gangue minerals. The application of leaching, physical separation, and wash out of salts has resulted in the decrease of phosphorus from 0.7 to 0.15 % and it is established that the major influencing factor is the concentration of acid and to a less extent duration of the leaching process. About two third of the phosphorus can be removed by roasting with 3 % CaO to hematite, coarse grinding to d50 0.3 mm, dry high intensity magnetic separation and leaching of the magnetic fraction with hydro-chloric or nitric acid.

Sep 1, 2012

Reaction between xanthate ions in solution and oxidized compounds present on the surface of galena to form lead xanthate is considered to be a side reaction not contributing to flotation, although accounting for some consumption of reagent. The direct reaction of lead sulphide with xanthate and oxygen to form lead xanthate is the most significant to flotation. Coadsorntion of dixanthogen is also involved. Previous work has shown lead recovery in lead rougher flotation to be a function of m [H+] where: m = concentration of xanthate in solution rHl = hydrogen ion concentration. A plausible explanation for this relationship is suggest-ed. Likewise, the experimental findings that the amount of xanthate adsorbed under certain conditions is a function of m'[H+] are explained in terms of reaction between xanthate ions and soluble basic lead salts such as PbO.PbS04? It is also shown that m[H+] should have a constant value in lead cleaners operating at a higher pH than the roughers. This conclusion is confirmed by plant data, and the value of the constant agrees well with the calculated value. The finding is useful in mill control.

Jan 1, 1965

By M J. Thurley, L Lindqvist, D Degerfeldt, J Nyström, R Nordenskjöld

Rock breakage is a major component of all mining and mineral processing operations with the particle size distribution linked to productivity through the comminution chain. Optimisation and automatic control of comminution, material handling, and agglomeration processes is a complex task with large potential for gains in productivity, and energy efficiency. A key factor in realising these gains is the requirement for fully-automated online particle size distribution measurement to provide the necessary feedback and input for control. Moreover, to enable automatic control system it is necessary to provide a consistent, reliable size distribution measurement that avoids the significant errors resulting from under-sizing overlapped particles and over-sizing clusters of fine particles. Published literature and observation of commercial systems indicate a body of predominantly 2D photographic based particle size measurement systems that suffer from a number of significant errors except in the simplest case of a monolayer of particles under good illumination with limited colour variation in the material. In order to overcome these limitations a university and industry collaboration developed three-dimensional particle measurement (3DPM) between 2006 and 2012, based on 3D surface profile measurement of the visible material on conveyor. 3DPM avoids particle delineation errors due to variation in material colour and shadows, detects overlapping versus non-overlapping particles, and identifies areas of fine particles as fines and not large rocks. 3DPM measures: the visible material and calculates its particle size distribution, bulk volume, detects boulders, and conveyor belt fill factor in an automated consistent manner. Furthermore, 3DPM’s advanced algorithms allow observation of particle variation that would otherwise be undetected without the capacity to identify visible areas-of-fines and overlapped particles. Boliden Mines has installed 3DPM at three operations for measurement between the stockpile silo and grinding mill, and measurement after the primary crusher. Fragmentation measurements across multiple years of measurement are presented with some observations of plant behaviour. In the future 3DPM results will be incorporated into automatic control strategies for plant optimisation. 3DPM is used across a wide range of material types and applications that also includes; limestone aggregate for quality control in manufacturing, agglomerates for closed-loop automatic control in chemical production, and measurement of coke for size-based blending feed control to the blast furnace in steel production. CITATION:Thurley, M J, Degerfeldt, D, Nyström, J, Nordenskjöld, R and Lindqvist, L, 2018. Automated, online measurement of bulk material size distribution on conveyor using 3D profile imaging at Boliden Mines, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 641–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R Crosbie, K C. Runge, E Tabosa, J K. McMaster

Flotation feed density is an operating parameter which is currently not well understood. Most models of flotation only incorporate its effect on particle residence time, but it is likely to have additional effects within both the pulp and froth phases of the machine. Test work was performed in MetsoÆs 3 m3 RCS test rig to investigate the effect of flotation feed density on metallurgical performance. The rig was operated at Rio TintoÆs Northparkes operation using flotation feed and scavenger tail. For each feed, tests were performed at different feed densities, and measurements were performed to estimate the pulp and froth recovery as well as other key flotation parameters (eg bubble size, turbulence and froth stability). Results of this test work have shown that the pulp density does affect key parameters of the flotation process in both the pulp and froth phases. Pulp phase kinetic rates decrease at high density and this is attributed to a reduction in the turbulence within the cell. Froth phase recovery, however, improves presumably because of a stabilising effect due to a greater loading of solids on bubble surfaces.There is a need for more research to be done to better understand these interactions so that metallurgists can determine the optimum flotation feed density to use at a particular operation, or within a section of a flotation circuit.CITATION:Runge, K C, Tabosa, E, Crosbie, R and McMaster, J K, 2012. Effect of flotation feed density on the operation of a flotation cell, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 171-178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By D Kent, R Paine

"Automated mining systems are increasingly being seen as a key requirement for a productive mining operation in the future. The importance of an integrated communication network infrastructure to support such systems is growing.This paper outlines the introduction of automated mining systems in large conventional mines as well as their growing role in block cave mines currently operating or being developed. The paper will then focus on a case study of how the communication infrastructure is fundamental to the operation of such systems and explain why the resultant communication networks require much more than just increased bandwidth (data capacity) to properly support the automation system within the overall mine operation.Mining operations already embarking down this road are discovering that the required network must be based on a true enterprise level architecture to not only enable the mine’s current plans for remote and automated mining, but also provide a scalable and integrated platform for future developments and requirements. The emerging issues for the communication network to truly support automation systems include: increased complexities of operating and maintaining multiple networks integration issues with disparate systems problems with reporting particularly as demands for corporate reporting and compatibility with enterprise systems become the norm ongoing management challenges, which will only increase with the proliferation of new technologies.The paper will explore how certain mining operations are addressing this by adopting a long-term strategy for automation deployment, which includes laying the necessary foundation architecture to meet their current requirements, while supporting their future visions for the fully automated mine.CITATION:Paine, R and Kent, D, 2014. Developing the foundation communication infrastructure to support remote and automated mining initiatives in underground mines, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 151–158 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014