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By R. P. Zahn

The need for quantitative mineralogical data to characterize ore types before they are processed is becoming increasingly necessary. Mineralogical data (modal abundances, grain size, liberation/locking characteristics, mineral textures and associations) can provide invaluable information to facilitate the identification of metallurgical issues that may arise during processing of a particular ore. This paper will discuss the use of QEMSCAN analysis in conjunction with bench scale flotation test work to determine metallurgical characteristics for several ore types that will be fed to the Morenci concentrator upon commencement.

Jan 1, 2007

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed.The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grade, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the final cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure I."

Jan 1, 1995

By M. Narita, S. Nakayama, M. Fujihara

Hibi Kyodo Smelting Co., Ltd. was founded in 1968 and celebrated its 50th anniversary in 2018. In 1972, we started producing copper cathode with a production capacity of 84 KTPY. Since the company founding, we have undertaken seven expansion projects, and our current copper-cathode production capacity is 290 KTPY. To increase our production efficiency, two tank houses were converted from Conventional process to ISA process in 2006 and 2014. In another investment, we equipped a continuous glue dosing system, which allowed for strict additive-concentration control, yielded quality improvements and reduced the power-consumption rate. Along with an increase in the production of copper cathode, the amount of impurities eluted from the anode increases. To solve this problem, the chelate-resin purification process that was introduced in 1983 was renovated, and impurities could be recovered more efficiently. In this paper, we report various improvements that have been implemented at the refinery since 2000. INTRODUCTION Tamano Smelter and Refinery of Hibi Kyodo Smelting Co., Ltd., founded in 1968, celebrated the 50th anniversary of its founding in 2018. The Tamano Smelter opened its No. 1 tankhouse in 1972, and began operating No. 2 tankhouse in 1984. Thereafter, with continuous production increases and technical improvements, electrolytic copper production was increased from 84 KTPY to 290 KTPY as shown in Figure 1. Table 1 shows the major operating facilities and operation data in 2017.In this paper, details of equipment introduced to continuously dissolve and add glue, various improvements made to the chelate resin process, enhancements made to the crude Ni sulfate process, and another vibrating screen introduced to the copper slime processing flow in accordance with the expansion of copper production capacity since 2000 are reported.

Jan 1, 2019

By M. Ataka

Magnesium alloys are not easy to plastically deform at room temperature and may suffer from edge cracking at high reductions, especially during sheet rolling. In this study, the authors attempted to improve the rollability by the low-temperature hot rolling method, in which the rolling temperature range is lower than that of hot rolling, and also by the edge-heating method, which locally heats sheet edges.

Jan 1, 2006

By Seong-Ho Ha, Shae K. Kim, Young-Ok Yoon

In the this study, surface segregation of Mg and Ca with Mg addition range from 5 to 10wt% in Al-Mg alloys with Mg+Al2Ca master alloy and its effect on the oxidation resistance were investigated. The addition of Mg+Al2Ca master alloy as the Mg alloying element led to the surface enrichment of Mg and Ca during high temperature oxidation. As a result of the oxidation test by TGA, the oxidation resistance of all the examined alloys was significantly improved with increasing Al2Ca content. The weight change of Al2Ca added Al-5Mg and Al-7.5Mg alloys indicated the complete oxidation resistance during the whole oxidation test time, while a slight weight increase was shown in the case of Al-Mg alloys even with Al2Ca addition. The improvement of the oxidation resistance in Al2Ca added alloys may be attributed to the formation of the protective oxide layer mixed with CaO and MgO on the surface.

Jan 1, 2015

By M. H. Govett, G. J. S. Govett

"The current American ""energy crisis"", occurring in the midst of a global debate on the adequacy of mineral supplies to support present and projected levels of world consumption, has focused attention on Canada as a major world producer of minerals. Exports of minerals account for approximately one-third of Canadian foreign earnings; more than half of these exports are to the United States. Although the United States is a net importer of most industrially important metals, with the exception of nickel and zinc, only a small part of American mineral imports are from Canada; these imports are minerals for which geographical proximity and strategic considerations are important. In the short-term, Canada is more dependent on her exports to the U.S. than America is on imports from Canada. It is argued that Canada, far from indulging in economic nationalism to preserve her resources, should expand her exports while the markets are available."

Jan 1, 1973

By S. Banisi, M. Pourkani, A. R. Laplante, A. Partoazar

"Canadian experience in industrial modeling of grinding, classification, and flotation kinetics was applied at the Sarcheshmeh copper mine, which processes 40,000 t/d of ore at 0.9 % Cu, in an effort to improve capacity and metallurgical performance. Mcivor's functional performance analysis was applied to ball mill cyclone circuits to maximize circuit capacity. Plitt's cyclone model was applied to predict how apex wear would affect classification performance, as part of a predictive maintenance program whereby the optimum wear period is determined for cast iron apexes. The flotation flowsheet was improved using Agar's optimization criteria. The impact of these technologies has been nothing short of spectacular, with an improved capacity of 1 S to 20""/o, and increased recoveries.1-IntroductionThe Sarcheshmeh copper ore body, which may rank as third or fourth largest in the world, contains 1 billion tonnes averaging 0.90 % copper and 0.03 % molybdenum. It is located southeast of Iran and has been processing 40,000 t/d of ore since 1982. The mine produces 100,000 tonnes of copper and 2,200 tonnes of molybdenum concentrate per year. After three stages of crushing, the ore with a Fso of 12. 7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70""/o finer than 7 S microns. The concentrate of the first stage of flotation is reground and the tailings constitute the main component of the plant final tailings. A concentrate with an average grade of 31 % Cu is obtained after cleaning and re-cleaning stages. Total recovery of the plant varies between 83 and 87 % depending on the operating conditions and ore type.To improve the overall performance of the plant, it was first decided to evaluate the performance of grinding, classification and flotation. Measures were then taken to improve performance using the following criteria: (i) The improvements should be of the types that have resulted in significant improvements in other plants (e.g. Shannon et al, 1993); and (ii) The proposed improvements must be achievable with the manual operation presently used at Sarcheshmeh. The outcome of this study could also help in making decisions on the implementation of automatic control systems in the Sarcheshmeh copper mine."

Jan 1, 1998

By S. Banisi, M. Maleki-Moghaddam

Direct observation of charge shape and its motion in industrial mills is not possible; therefore, a combination of analytical and physical studies is used to determine charge trajectory. Software packages, which predict charge motion consider only the outermost layer of charge (single ball) and ignore the charge and the interactions of grinding elements. In the new version of the GMT (Grinding Media Trajectory) software, the effect of liners specification and bulk load on charge shape and trajectory are considered. The charge trajectory was measured in a laboratory mill with the diameter of 100 cm and length of 21.5 cm with the transparent end and compared with that of the old version of GMT. Four types of polyurethane rings were accurately machined to scale down the liners arrangements at two industrial mills. The model mill was operated at 55, 70 and 85% of the critical speed for five levels of mill filling (10, 15, 20, 25% and 30% by volume). The experiments indicated that the end walls effect was negligible for the model mill with the length of 10.8 cm and beyond. The proposed relationships to correct the trajectory and charge shape were validated by using the new liner of the Gol-E-Gohar iron ore company AG mill. The positions of shoulder, toe, toe departure and impact points were predicted with the relative errors of 5, 0.7, 2 and 0.2%, respectively. The GMT software was updated with the new relationships. The results of GMT simulation indicated that when the lifter face angle increased from 7 to 30°, the distance between the charge impact point and the toe decreased from 40.1 to 11.2° for 30% filling. The change in the position of the impact point meant increasing the probability of charge impacting the toe, not the liner which favored more efficient comminution practice.

Jan 1, 2016

"In developing a backfill system handling tailings feed to and from the storage silo, it is necessary to establish a slurry laboratory to develop the technology and silo design criteria. This paper presents the principles involved in such development and the importance of testing principles for optimizing the slurry system. Evaluation procedure based on experiments is applicable to a wide range of materials and allows silo design by scaling up the data gained from model tests. Silo simulation has been successful to design and operation, so becomes an effective approach to backfill applications. IntroductionThe silo is a device comprising specialized equipment and operating with related procedures for storing and handling the mill rejects as backfill slurry. It provides a steady supply of the solids slurry, prepared at desired pulp density under the continuous feed conditions. Because the silo system is designed to accomplish specific objectives when dealing with a particular mill tailings slurry, it is necessary to characterize certain slurry properties, behaviour of the solids slurry and understand the silo performance to establish design criteria. Bench-scale, pilot-scale and dewafull- scale experiments were employed in developing the load-storage-discharge system, and routine procedures are now available for pre-design testing. Silo model experiments and full-scale tests were conducted to define the design parameters and evaluate the silo performance. A silo can be designed by scaling up the silo model geometry and data obtained during tests.Since the early 1960s, silo backfill systems have been widely established. The shape and size of the silo and the operation procedure, as practised, all appear to be relevant to successful operation. Understanding the basic material properties and behaviour of solids slurry retained in the silo will help perfect the silo design, operation procedure and, consequently, improve the silo performance."

Jan 1, 1997

Vast quantities of cosmic material, ranging in size from fine dust to large meteorites and planetoids, have been colliding with and accumulating on the earth since its origin 4.5 billion years ago. There are less than twenty well preserved meteorite craters and Jess than thirty fossil craters or astroblemes on the present face of the earth. On the moon, there are approximately 200,000 craters on the visible face alone -the largest crater being 132 miles in diameter and attaining a depth of 16,000 feet. Making allowances for the different physical conditions on the moon and assuming that these lunar features are of impact origin, the indifference is that, since primeval time, large numbers of celestial objects have also encountered the earth, but that both the topographic expression of the impact and the objects themselves have been destroyed by weathering and erosion. It may be reasonable to suggest that additions of cos-mic bodies have materially altered the chemistry of the earth's crust from place to place and that the impact of large meteorites and asteroids has created zones of weak-ness in the crust that could be the center of magmatic intrusion and mineralization.

Jan 1, 1965

By M. Mirnezami, J. A. Finch, M. S. Hashemi A.

This study examined the effects of pH and sulphate concentration on the surface charge and stability of alumina and pyrite dispersions. The relationship between these properties was investigated using measurements of electrophoretic mobility and settling velocity. The maximum aggregation for both minerals was observed near the iso-electric point (iep) where the force of repulsion is at a minimum. Aggregation decreased at pH values away from the iep, where an increased surface charge causes electrostatic repulsion between particles. Zeta potential data revealed that sulphate ions were adsorbed only on positively charged surfaces for both minerals. Adsorption of sulphates on the alumina surface increased aggregation by reducing the surface charge from >+25 mV to close to zero. These results indicate an electrostatic bonding of sulphate ions to alumina surface. Preliminary results on the interaction of pyrite and sulphate ions indicate a similar response.

Jan 1, 2004

By Chris G. Dobson

Introduction The Britannia mine is at Britannia Beach, on Howe sound, approximately thirty miles from Vancouver. The first claims were staked in 1898, and a local company was formed at that time to develop them. In 1904, Mr. Grant B. Schley became actively interested in the property and in the following year the Britannia Mining and Smelting Company, Limited, was incorporated to operate it. This Company was taken over a few years later by the Howe Sound Company, Limited. The mine comprises five more or less separate ore-bodies, which have produced approximately 20,000,000 tons of ore to date. The East Bluff ore-body, with which the present paper deals, is well suited to large-scale mining by means of carefully placed powder blasts. It covers approximately an acre and lies in the slate footwall, in a bay produced by a fault. The hanging-wall side, on the west, forms the face of the Bluff glory-hole, which extends to the 1,200 level. A portion of this ore was available for breaking into this old glory-hole, below which four bulldoze chambers could quickly be built. Mining of this block is complicated by a very soft footwall, which 'runs' badly when broken. In stoping, care is taken to guard against the hazard of dilution by deliberately leaving a small portion of ore on the footwall. Some of this will undoubtedly be lost, but it is hoped to recover a fair amount of it after the major drawing is completed. The deposit occurs in a greenstone which has been highly silicified following brecciation. The chief minerals are chalcopyrite, sphalerite, and pyrite. Concentrates of copper, zinc, and pyrite are made at the mill. The average grade of ore runs 0.7 per cent copper, 1.5 per cent zinc, and 0.03 oz. gold per ton. The rock, which is practically a chert, is extremely hard, but shatters well. Both in stoping and drifting, holes must be closely spaced and powder used generously. Development When development work started in the East Bluff, there were no raises and only one drift on each level in this section of the mine. After blocking out the ore by thorough diamond drilling, a production of two thousand tons per day was set as a goal. To obtain this tonnage from so small an area required a great deal of carefully planned and well timed development work.

Jan 1, 1935

By Clemens Kuhnert

"Nickelhütte Aue GmbH is specialized in the recycling of waste materials containing non-ferrous metals. We treat nickel, copper, cobalt, vanadium, molybdenum and precious metal containing materials like spent catalysts, ashes, dusts, grindings, liquids, slurries and sludge's as long as they contain one or a combination of the above mentioned metals. In our pyrometallurgical works we produce non-ferrous metal concentrates suitable for further treatment in our hydrometallurgical plant where we refine Ni-, Cu-, Co- and V-chemicals. Our production is based on synergy effects due to the combination of pyro- and hydro-metallurgy. As an example we can mention our heat recovery system and internal recycling of by-products. Furthermore, the use of alternative fuels instead of fossil fuels contributes to the economic and environ-mentally friendly treatment system.INTRODUCTION Nickelhütte Aue GmbH (NHA) can look back on nearly 400 years of tradition as a pyrometallurgical works and recycling company. The existence since its foundation in 1635 as a blue dye works shows responsible and successful action in the past. Therefore, we see highest customer service, minimization of interferences with nature by closing material cycles and maximized health and occupational safety protection by avoiding injuries and diseases, still as our future duties. These duties are evaluated and monitored by an integrated management system that meets the standards of DIN EN ISO 9001, 14001, 50001 and BS OHSAS 18001. We commit ourselves to the observance of all juridical and customized demands. The management and the department managers perceive their model function. We require responsible action from all employees. To protect the continuity of our enterprise, we will also perform in future continuous improvement of products and their quality, as well as steady progress in the areas of environment protection, health protection and industrial safety. Equally the effectiveness and propriety of the management system is checked and developed regularly. In order to obtain the objectives resulting from this policy, our company determines activities and measures by involving all employees."

Jan 1, 2017

By D. K. Storer, W. Lee, S. Tkach

"A microcomputer-controlled multi-probe K-40 monitoring system was developed internally for the Phase II mill at the Lanigan potash mine. The K-40 probes were mounted in a variety of positions in several process streams, ranging from dry ore on a conveyor belt to brines and slurries. A description will be presented of the objectives, the equipment and the difficulties encountered in correlating results.IntroductionThe successful control and optimization of most metallurgical processes involves monitoring not only physical parameters such as flow rate and temperature, but also the chemical compositions of critical streams. Composition has proven difficult to measure on -line in industrial scale processes. However, in potash processing there is a convenient chemical parameter that has long been utilized to measure in situ the concentration of potassium chloride (KCl). Potassium has a long-lived isotope which is slightly radioactive. K40 decays by beta elimination to Ca40, ultimately radiating a characteristic gamma-ray photon. This gamma emission when detected by scintillation counter can be used to estimate the concentration of potassium in a process stream."

Jan 1, 1990

By Chris Twigge-Molecey

"Over the last 50 years there has been a dramatic evolution in the metallurgical engineering field in Canada. In the 60s the field was dominated by large American and UK groups, often selling major process and equipment packages. The local content was limited to wrap around facilities and the civil and structural work. The mining and metallurgical companies had strong internal teams to lead these projects. Over the decades and business down cycles the large foreign contractors disappeared or re-structured and the mining companies largely shed their engineering and project management groups. The resulting gap was filled by a cadre of local specialist engineering companies, some of whom have grown to be world leaders in the field. The paper traces this evolution and examines the underlying causes and consequences."

Jan 1, 2015

By Anthony McDonald, Dominic Verhelst

"Hudson Bay Mining and Smelting Co. Ltd. (HBM&S) started up a zinc plant and smelter in late 1930, employing technology of that period. The zinc plant has since converted from a roast/leach operation to a two stage pressure leach operation to eliminate sulphur dioxide emissioms. The smelter, however, is still continuing with much of the original roaster/reverberatory furnace technology. This paper reviews the process flow of the copper smelter, with some comments on past and recent changes.Smelter FlowsheetPrior to July 1993, the HBM&S smelter operation consisted of seven areas, namely feed preparation, roasters, reverberatory furnace, converters, anode casting, fuming plant, and dust collection. A simplified smelter flowsheet is shown in Figure 1. The data for tonnage of materials moving through the circuit are presented in Tables I to 4, and are representative of the time period from July 1992 to June 1993. A change in the zinc plant technology in 1993 resulted in the elimination of a zinc-bearing sulphide leach residue from the smelter feed blend, thereby greatly reducing the zinc content of slag produced in the smelter. Consequently the fuming plant and ancillary equipment, such as the drying plant, were shut down. These areas will, however, be described. With the closure of the zinc fuming furnaces all the slag from the reverberatory furnace is now discarded to stockpile.The over-all smelter metal recoveries are 96% for Cu and rn.5010 for Au and Ag. Figures 2 and 4 indicate historical production numbers of copper, silver and gold, respectively. A review of the minor element distribution in the smelter can be found elsewhere."

Jan 1, 1994

By K. Sakai, M. Miyaue, T. Aoki, T. Tani, S. Tanaka, N. Kudo

In the planning stage of a tunnel, due to limited technology in the geological survey and the financial restriction, tunnel supports are often designed from unsatisfactory information, and the tunnel construction is started. Therefore, "Information-oriented construction" is carried out in the construction stage, in which the design is rationally verified and modified by observations/measurements. Moreover, the ground conditions ahead of a tunnel face must be predicted for efficient and safe tunnel construction. The authors have examined effective prediction methods to the ground conditions ahead of a tunnel face under construction of mountain tunnels (Aoki et al., 2010) in view of the established method (Schubert et al., 1995). Though the prediction method of Schubert requires the displacement in the direction of tunnel axis, it is difficult to obtain its accurate data by the electronic distance meter. Then, we have proposed a method that uses tilt sensors installed at the tunnel crown near the face to obtain the slight tilting information. To measure inclination of the tunnel crown, this inclinometer was originally developed as a daily control measurement, such that the geological condition and its possible change behind the face could be detected early, and a steady advance and construction safety could be ensured. This paper describes the method of forward prediction mechanism and advantages of this suggested method. It then presents the typical results of a field verification test at a tunnel under construction and an example of evaluation of the ground conditions ahead of the face based on the 3D numerical analysis in three types of condition changes of ground deformation moduli.

Jan 1, 2015

By Chas. L. Emery

"The laws of rock mechanics apply equally well to all rock structures, and open pits are not exceptions. The concepts and some arguments about the emphasis to be placed on various aspects of open-pit design are discussed in this article.RocksROCK can be described as a granular material consisting of grains and glue. The grains may be fragments of other rocks or polycrystalline aggregates. The glue may be ferruginous, calcareous, argillaceous, siliceous or other material connecting the grains. In a crystal intergrowth, the outer layers of the crystals in contact with each other may be considered to act as a glue. Water may be a glue in clay or a grain in a crystal structure. Air and other fluids or gases are grains if they occupy spaces in a granular mass. Such grains are functional either chemically or mechanically or both."

Jan 1, 1966

By William James Kempson

This paper discusses ore handling systems in shafts. These are considered from the loading facility at shaft bottom all the way through to the discharge mechanism in the headframe. These systems will be discussed from the following perspective: i. Intrinsic safety of the systems ii. The efficacy of the systems to perform consistently iii. The maintainability of the systems iv. Overall system cycle times Particular emphasis is placed on the following specific areas: 1. The Shaft Bottom Loading Facilities The various shaft loading systems currently in use are discussed, the selection parameters surrounding these are quantified and the specific selection criteria are outlined. 2. The Various Skip Configurations In this section the various skip configurations in use around the world will be described and the specific design details associated with these will be highlighted. The advantages and disadvantages of these systems will be compared and the overall efficacy of these will be discussed. 3. The effect of the loading and skip configurations on the Load Cycle Times. The overall cycle time which can be achieved by a shaft system is strongly dependant by the speed and efficiency with which the ore can be loaded and transported out of the mine. The potential of the various systems to be optimized will be discussed. The emphasis of this paper is to highlight the lessons which have been learned with respect to ore transport system design and provide a common basis against which these can be compared in future applications.

May 1, 2013

By K. Bowes, M. D. Maley, R. J. Ring

The Honeymoon Uranium Project is an acid In-Situ Recovery (ISR) mine in South Australia. It was previously operated for approximately 18 months before being placed on care and maintenance in 2014, it was then acquired by Boss Resources in 2015. Boss has been performing a number of studies to plan for reopening of the mine, including a successful field leach trial (FLT) in 2017. The current configuration for uranium precipitation at Honeymoon is a batch process. Whilst this achieves effective uranium recovery, the precipitates produced are often very fine, with poor settling and solid/liquid separation characteristics. Continuous precipitation, involving recycling of solids, has reportedly been successfully utilised in other operations to increase the particle size and density of the product, leading to solids that can be more readily dewatered, dried and drummed, with less fines and dust generation. However, no operational data are available from such operations.

Jan 1, 2020