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By David F. Machuca-Mory

Modelling the geometry of a vein is a crucial step in resources estimation. The resulting models are used as mineralization domain boundaries and have a direct impact on the tonnage of estimated resources. Deterministic models are often built using time consuming wireframing techniques usually based on hand interpretation of the drillhole intercepts. Another approach consists in coding the drillhole samples by a function of their distance to the veins contacts. The coding is subsequently used for modelling the vein contacts away from drillholes. This is a more efficient approach and is able to provide a measure of tonnage uncertainty. The use of location-dependent variograms improves the modelling by incorporating local changes in the anisotropy of the vein structure. This combined approach results in more realistic vein models, particularly when the geometry of the vein has been are altered by folding, shearing and other structural processes. The approach is illustrated on a realistic case study.

Oct 1, 2009

By E. Brzychczy

Artificial intelligence techniques are ever more frequently implemented in the modern world. One of their numerous uses is supporting enterprise management. Intelligent techniques and intelligent information technology (IT) systems can be implemented in mining-related issues as well. The author of this article concentrates on supporting the process of planning mining operations by intelligent systems and techniques. The author also underlines the importance of knowledge accumulation in a mining enterprise (especially tacit knowledge) as well as its efficient storing and using. Additionally, the author provides a short description of characteristics of intelligent IT systems and indicates their capabilities in planning mining operations. She presents two solutions, namely: an advisory system which supports the process of planning preliminary works and exploitation works in hard coal mines, and a method of modeling and optimizing mining operations. Finally, the author indicates a few possible future development trends of intelligent systems - the intelligent systems of decision support.

Aug 1, 2013

By Yongqiang Liu

Background For refractory gold ores with high carbonate contents ! Acid pressure oxidation ! High acid consumption (if low sulfur content) ! Low oxidation efficiency due to CO2 in autoclave ! Problems with slimy precipitates (gypsum, etc.) ! Alkaline pressure oxidation ! Difficulty in fixing arsenic ! Low gold dissolution due to iron hydroxides/oxides coating ! High reagent costs Summary ! Carbonate and sulfide minerals had similar floatability across the pH range tested (5 - 12) using sodium oleate as a collector; ! Thioglycollic acid or citric acid depressed the flotation of pyrite but could not depress chalcopyrite when used alone; ! Combination of thioglycollic acid and citric acid had a much stronger depressive effect, and the mixture depressed chalcopyrite as well as pyrite between pH 8 and 11 without affecting the flotation of calcite and dolomite; ! Calcite could be separated from chalcopyrite and pyrite; dolomite could be separated from pyrite but not from chalcopyrite under the tested conditions.

Apr 1, 2005

By R. R. Bassermann

THE property of Howey Gold Mines, Limited is situated at Red Lake, Ontario, one hundred and seventy-five miles east of Winnipeg and eighty miles north of the Canadian National Railway line. The mine has been a continuous producer since April, 1930, and at present is hoisting 1,350 tons of ore per day. The shaft consists of three compartments (see Figure 1, sketch B). Hoisting is done by two skips in balance, one of which is interchangeable with a cage. Sinking had been carried out at three different periods. From the surface to the 550-foot level, the sets had been spaced at seven-foot intervals, from the 550-to the 1,060-foot level at six feet, and from the 1,060-to the 1,500-foot level at five feet. During the five years of operation, the shaft had become so badly worn, due to spill from the tipples and, to a certain extent, from the loading pockets, that re-timbering was considered necessary. It should be explained that no crushing is done underground because of the ad verse effect this would have on the efficiency of the sorting. The grizzly rail clearance above the ore pockets is fourteen inches and consequently the ore hoisted is extremely coarse. More than average spill from the loading pockets and tipples under such conditions is inevitable, and it is debatable whether underground crushing with consequent increased sorting costs would not be justified. The cost of complete re-timbering according to standard practice would have been prohibitive both directly and indirectly: A lengthy shut-down of the shaft, with the consequent disorganization of the staff and workmen, could not be considered. Accordingly, it became necessary to devise some method of repair that could be carried to completion in a very limited period of time. The shaft timber for the first 250 feet was not in need of repair. From the 250-foot to the 1,060-foot level the wall plates, posts, and blocking were in good condition. These had been protected by a one-inch plank lining put in at various periods during the past three years without interfering with hoisting operations. The end plates and dividers, however, could not be protected in this manner because of the lack of skip clearance. It was decided that, if the dividers in this section could be replaced, the shaft would be as satisfactory as if completely re-timbered. Several factors had to be taken into consideration in deciding on a suit-able method of repair. In the first place, the tipple plates had to be re-designed. To complete the job in a reasonable time, not only had work to be done on the tipple, but simultaneously from several points in the shaft itself. Since all power cables, pipe lines, etc., were in the manway compartment of the shaft, this compartment had to be left undisturbed.

Jan 1, 1935

By Aleksandar N. Nikoloski, Tendekayi Tapera, Glen P. O’Malley

Chalcopyrite (CuFeS2) and enargite (Cu3AsS4) are among the most important copper sulfides. At present, many known deposits of these minerals are uneconomic to process because they are of too low grade, insufficient size or too remote to be cost effectively treated with conventional technologies that can deal with their refractory nature. Therefore, developing an effective, low cost extraction process for recovery of copper from them is important. The research presented in this paper will deal with potentially cost effective strategies involving catalysed processing, studied under conditions relevant to recycle heap leach conditions. The present account summarises some of the main findings from the research program carried out at Murdoch University between 2014 and 2018 that has investigated the effects of the common leaching parameters, major and minor species present in the leach system and additives on the rate and extent of copper extraction from low-grade ores, in which primary copper sulfide minerals such as chalcopyrite and enargite were the dominant copper minerals. The study involved batch leaching tests, detailed structural and mineralogical characterisation and thermochemical modelling under conditions relevant to heap leaching. The results have demonstrated that silver in particular has a strong catalysing effect on the extraction of copper from ore under the leach recycle conditions and, at an adequate dosage, can effectively overcome surface passivation, enabling almost complete extraction of copper from chalcopyrite as well as enargite. The aim of this paper is to present the effect of the studied additives and to briefly elaborate on the mechanism of the silver catalysed leaching process. In addition, the presence of certain secondary agents was shown to lower the critical dosage of silver and promote extraction. The data from the study allowed the development of a theory for the silver catalysed reaction mechanism, which enables further optimisation and cost-effective application of this strategy in practice. INTRODUCTION Researching the extraction of copper from chalcopyrite is important as it is the most abundant copper mineral in the earth’s crust. The majority of ores containing this mineral are processed by flotation to produce a concentrate, followed by smelting and electrorefining. However, most reserves available nowadays are of low grade or limited in size, and therefore not suitable for this conventional approach. Hydrometallurgical processing via heap leaching with or without the aid of bacteria has been shown to be potentially economical. Chalcopyrite is refractory though and suffers from slow leaching kinetics and poor overall extraction, so understanding the mechanism of how it leaches has received significant attention by researchers working in this field over the past 50 years. The refractoriness, which is the main issue with the hydrometallurgical approach, is generally described as passivation of the chalcopyrite surface whereby a surface coating is formed that blocks the reaction interface or wetting of the chalcopyrite, limiting the copper extraction. Exactly what this layer is made of or how the issue could be overcome has been the subject of intense study and debate for many years. One of the limitations of the work to date is that much of the research focus has been on typical initial leaching conditions, while there has been relatively little research into how the leaching is affected under recycle solution conditions where certain metal ions (Fe, Mg, Al) have often accumulated in the liquor. This occurs because the leach solution exiting a heap contains many species from the dissolution of gangue minerals and typically this solution is returned to irrigate the heap, once the copper has been removed, leading to an accumulation of these species.

Jan 1, 2019

By Richard W. Hutchinson, Christopher Osterman

The Selebi-Phikwe deposits are hosted by amphibolite to granulite facies gneisses of the Limpopo belt. The sulfide orebodies are generally stratiform and conformable to the foliation of the wallrock gneiss. Sulfide remobilization has occurred during metamorphism and has produced discordant sulfide veins, called piercement structures, which project into the hanging wall and footwall gneisses. These piercement structures are compositionally similar to the stratiform sulfides, consisting mainly of pyrrhotite, pentlandite and chalcopyrite. However, texturally the piercement sulfides are coarse grained and inclusion-free, whereas the stratiform sulfides are fIne grained and packed with tectonically produced wallrock inclusions. The piercement structure sulfides and adjacent stratabound sulfides were sampled and analyzed for major base metals and PGE's for comparative purposes. Most of the piercement structures were enriched in Cu, Ag and Au, whereas they were generally depleted in Ni, Co, Fe and PGE's. Changing elemental associations were observed from the stratabound sulfides and along the length of the piercement structures. This and the degree of depletion or enrichment of various major and minor elements in the sulfide piercement structures may reflect the relative mobilities of metals under metamorphic conditions. The similarities between sulfIde piercement structures and the footwall Cu-PGE veins in some Sudbury deposits are reviewed.

Jan 1, 1994

By Melanie Grob

Two commonly estimated fractal dimensions, called b and D values, represent statistical characteristics in the distribution of magnitude sizes (b) and spatial hypocenter locations (D) of microseismic events, respectively. We postulate that the values of b and D are related to specific stress regimes. Through different case studies of fluid injection into an oil/gas reservoir or geothermal field, we infer that the measured temporal variation in fractal dimension b is most likely due to significant changes in the local stress regime. The fracture dimension D indicates the spatial clustering of events. The distribution of these events can vary with time because of stress perturbations that (re)activate fractures whose direction favours their movement under a specific stress regime. Thus a combined statistical study of these two dimensions can help infer the variations of local stresses in a reservoir.

Jun 1, 2012

By T. G. Phillips

"This paper gives an inside look at a bulk terminal and describes the preparations that must be made by a company in developing such a terminal and its position in today's traffic pattern. The following headings cover the subject material: (a) Traffic pressures, their detection and measurement, (b) position in the traffic flow -selection of site, (c) transportation connections -present and possible future routes, (d) engineering studies and costs, (e) contracts, the basic material for insured traffic, (f) financing, (g) budgetary control, (h) development of new techniques, (i) growth into new cargoes or cargo-handling methods and (j) consolidation."

Jan 1, 1968

By R. T. Elworthy

Canada ranks second in the list of world consumers of natural gas. In 1923 our production was nearly fifteen million thousand cubic feet valued at $5,800,000. Our output, however, appears very small compared with that of the United States, which in 1923 totalled over one thousand and eight million cubic feet, valued at $240,000,000. Natural gas is found in commercial quantities in three? provinces in Canada. New Brunswick: Natural gas in New Brunswick has been utilized commercially only since 1912,although the investigation of oil and gas possibilities of the province commenced as early as 1859. The annual production is a little more than one-twentieth of the total Canadian production and remains fairly constant from year to year. Ontario: In Ontario the earliest gas wells were drilled in Essex and Welland counties between the years 1885 and 1890. On account of the small demand in Canada the cities of Detroit and Buffalo were supplied with large quantities of gas from these wells, but this export was curtailed in 1898 and finally ceased in 1900. The production of natural gas in Ontario, mainly from fields in Lambton, Kent, Essex, Norfolk, Haldimand and Welland counties, increased rapidly from 1900 until the peak was reached in 1917, when over nineteen million thousand cubic feet valued at $3,641,587 was consumed.

Jan 1, 1925

By T. Takayama Filho

Votorantim Metais Zinco is a smelting facility which produces SHG zinc, zinc alloys, sulfuric acid, liquid SO2, copper sulfate, cadmium metal and silver concentrate. It is located at Juiz de Fora, Minas Gerais State, Brazil. This facility has been operating since 1980 and its current capacity is 95,000 tonnes of zinc per year, using mostly imported sulfide concentrates.The plant uses the conventional roast-leach electrowinning (RLE) process, in which iron is removed from the circuit as jarosite. The residues generated by the RLE process, which amount to about 200 t/day (dry weight), were until 10 years ago, deposited in tailing ponds having no impervious lining. More recently, jarosite and other wastes have been deposited in a properly built reservoir, but this is reaching its maximum capacity. In order to decommission these disposal operations and to reclaim the sites in an environmentally acceptable manner, Votorantim Metais concluded in 2004 a rehabilitation project for the old tailings pond and prepared detailed plans for managing the current and future disposal of jarosite-bearing residues. This paper describes the procedure for removing iron from the hydrometallurgical circuit and discusses the past and current status of the residue disposal sites, as well as the future challenges related to the environmentally acceptable handling of iron residues.

Jan 1, 2006

By Katherine (Kate) Bruce

Aurora College ? Yellowknife Campus, in partnership with the Northwest Territories Mine Training Society and industry partners, has developed a 6 ? week program on Underground Mining for delivery in Northern communities. The goal of the program is to inform and connect Northern residents to the career potential at existing and future mining operations throughout the Northwest Territories. The program content includes an introduction to the mine life cycle, basic underground mining methods, the use of technology in training via desktop simulators for underground mining equipment, safety in the workplace, and essential skills training (Ready to Work - North) and assessment. Students completing the short program may then choose to continue into a long (12-week) program to be offered at the Yellowknife Campus. This program expands upon the initial introduction and includes modules on NWT geology, environmental studies, underground mining processes and underground mining equipment operation using the larger enclosed cab simulator for a variety of equipment being used at northern mining operations. Success of both programs will depend upon a variety of factors, many of which are outside of the control of the developers of the training modules. These will be investigated throughout the presentation. Connecting northern employers with northern employees is a major concern. It is hoped that through the development and implementation of a program such as this, that the connection can be made and sustained allowing continued employment for the life of northern mining operations.

May 1, 2008

By F G. Cooke

"This paper describes a medium-sized copper mine's results in making innovations and changing operational practices to combat increasing expenditures due to higher labour and supply costs, extended workings, scarcity of experienced manpower and problems created by deteriorating ground conditions.OPEMISKA COPPER MINES (QUEBEC) LIMITED is located at Chapais in the Chibougamau area, in central eastern Quebec, approximately 300 miles north of Montreal and 150 miles north west of Lake St. John. The latter area, developed by lumbering and farming, has supplied the majority of the employees, who, with training and experience and a desire to work and improve themselves, have become the backbone of the Company's 600 personnel.Opemiska began production in 1954 at a rate of 400 tons per day, using diesel power and road transportation. The rate was progressively increased and, by 1959, with hydro-electric power and rail transportation, the mine had reached its present production rate of 2,000 tons per day. It has produced concentrates containing over 430 million lbs of copper."

Jan 1, 1968

By M. Massinaei

Recently constructed circuits have included multiple stages of columns in a variety of applications, from roughing to cleaning. The Miduk copper concentrator (in south-eastern Iran) is one of the unique mineral processing plants which use column flotation cells as rougher. As the bulk of final concentrate is produced by rougher columns, optimized metallurgical performance of these cells is crucial. This paper will present the study and optimization of, a froth washing system of columns. For this purpose, the cross-sectional area of orifices was increased and their orientation altered. Concentrate assay for copper and silica, in addition to bias rate were found to be the assessment criteria. Modification of the wash water system resulted in increasing the purity of rougher and final concentrate. Negative bias and short-circuiting of wash water into the concentrate launder were the main causes of improper froth zone washing in the former system.

Jan 1, 2007

TSUG Presentation Overview What/Who we are? Objectives & Mandate How to become a member (who qualifies)? Meeting Agenda?s & Frequency Q & A SMART is an association of mining companies that meet regularly to coordinate the technology development needed by the mining industry. Since 1995, the member companies and institutions have directed research and influenced the manufacturers and suppliers to improve surface mining technology and services. SMART actively supports learning seminars, collaborative research projects, and user groups. Members of SMART include some of the major surface mining companies in North America and Australia. These companies have recognized the value that collaboration can bring to the needs of individual organizations as well as the global mining industry.

May 1, 2008

By C. A. Godden, T. N. Atkinson

Metallographic techniques developed from studies of corrosion films and electroplated coatings on aluminum alloys, are discussed. These methods, the result of work at the Naval Research Establishment, give extremely flat fields at the interface despite the large difference in hardness, in cases where electrolytic polishing could not be used. Techniques to overcome the similarity in refractive index of immersion oil, aluminum ox1d~, and mounting plastic are also considered, as are methods for improving visual and photographic contrast in areas of interest. A device for marking specimens is also de-scribed. ELE•CTROLYTIC polishing is inapplicable in the study of surface films on aluminum, whether corrosion films or electrodeposits. Mechanical procedures must there-fore be followed. Sample flatness and edge retention are of paramount importance. Special measures are required in the study of oxide films, because of the close proximity of the refractive indices of aluminum oxide, mounting plastic, and immersion oil.

Jan 1, 1962

By E. Herrera, L. Mariscal

"Ilo Copper Smelter operates since 2007 with an ISASMELTTM furnace as a single smelting unit (1,200,000 tpy) associated with two Rotary Holding Furnaces for separation of matte and slag, and which directly produces a discard slag. Southern Peru continually has been improving the slag chemistry of its ISASMELTTM furnace in order to reduce copper losses, given its big economic impact due to large slag mass generation. The present paper describes the influence of the CaO, Al2O3 and magnetite content in the slag of the ISASMELTTM furnace correlated with the SiO2/Fe ratio and its liquidus slag. Also it defines the best slag chemistry and operating practice in order to reduce the copper losses without compromise the bricks life of the furnace.INTRODUCTIONIlo Copper Smelter of Southern Peru (Grupo Mexico) is located on the southern coast of Peru, and treats mainly copper concentrates produced in its own mines (Toquepala and Cuajone).The modernized smelter was commissioned in 2007 and operates with an ISASMELT™ furnace as a single smelting unit (1,200,000 tpy), which is associated with two Rotary Holding Furnaces (RHF) for separation of matte and slag. This slag is directly sent to the dump. Figure 1 shows the smelter flow diagram.The ISASMELT™ process is a bath-smelting process using a single lance. The lance tip is immersed into a molten slag bath contained within the stationary, vertical, refractory-lined ISASMELT™ furnace. The injection of oxygen-enriched air, through the lance into the slag results in a highly turbulent molten bath. Feed material falling into the turbulent bath from above reacts rapidly, resulting in extremely high productivity for a relatively small bath volume."

Jan 1, 2012

By S. J. Cook

The subject of capital and the Canadian mining industry is so broad as to be impossible of comprehensive treatment in brief form. The purpose of the present paper therefore will be only to outline in a meagre and somewhat sketchy way the nature and extent of the mineral industry in Canada and to point out those features which are likely to be of general public interest. Canada's mineral industry has a long and creditable production record. The? value of the output per capita rose from $2.23 in 1886 to a maximum of $26.40 in 1920 and the value of the products from ten million dollars in the former year to almost two hundred and twenty-eight million dollars in 1920. Compared with other primary industries and on the basis of the value of production, mining held third place in Canada in 1920, the premier position going to agriculture and the value of forestry production placing that industry second in the list. In the mineral industry, between six and seven thousand properties are operated annually giving employment to up- wards of sixty thousand employees to whom about seventy-five million dollars is paid in salaries and wages. During 1923, seventeen mineral products reached a production value of one million dollars or over in Canada and in order of the values assigned these were: coal, gold, nickel, cement, cop-per, silver, clay products, lead, asbestos, natural gas, stone, zinc, lime, cobalt, sand and gravel, gypsum and salt.

Jan 1, 1924

By P. Mattar

The geotechnical importance of studying fluid flow through porous media and soils in particular, becomes evident when dealing with groundwater movement in surficial geomaterials that can be initiated by hydraulic gradients that develop during construction activity, groundwater extraction, impounding of reservoirs and groundwater recharge during adverse climatic events. In a geotechnical context, rocks are regarded as virtually impermeable materials, with comparatively greater resistance to flow of water through their pore structure. The importance of the permeability of rocks comes to the forefront when deep geologic formations are used in geoenvironmental activities for disposal of hazardous and toxic materials. The permeability of the rocks encountered is of critical importance to these geoenvironmental activities since the movement or transport of the hazardous materials during their eventual release will be largely governed by the permeability characteristics of the geologic formation. The estimation of the permeability characteristic of geologic formations is a non-trivial exercise since the measure of permeability can be influenced by the scale at which the measurement is made. Regional-scale and borehole-scale estimates of the permeability can be greatly influenced by the inhomogeneities, including fractures, fissures, solution channels and other anomalies that are present in naturally occurring geologic media. These anomalies are considered to be site specific and can only be determined in a reliable fashion by either conducting tests at the appropriate scale or in the regional-scale through inverse analysis of tracer movement patterns in rock masses. The estimation of the permeability of intact units of a geologic medium has important geoenvironmental applications in connection with storage of wastes since the units in which repositories will be located should be sparsely fractured and the sealing of the fractures and fissures are a prerequisite to developing an efficient solution for storage. The intact permeability of geomaterials is therefore regarded as an important property that influences efficiency and reliability of geoenvironmental solutions for deep geologic disposal. The permeability of geomaterials such as concrete and cementitious grouts are also important to many geoenvironmental and infrastructure applications where durability of structural materials in general and cements used for sealing deep boreholes and other access shafts employed in waste management endeavours is influenced by the permeability characteristics of these materials

May 1, 2009

By A. Todd Davis

"Introduction“CAN YQUR Company afford not to train?"" This question was asked by Jack Taylor in the Factory Management Magazine for June, 1950. Mr. Taylor went on to say, ""No, it can't; no Company can"". It's true that many training programmes have not done the job they were designed to do because of a number of factors such as parts of management resenting training, management failing to understand the abstract values of training, and management giving impossible assignments or picking the wrong trainers. However, Mr. Taylor summarizes his article by saying that a properly-designed and •conducted training programme brings a company or a corporation to the point where the question is: ""Can my Company afford not to train?""About two years ago, in July, 1952, Nevada Mines Division of the Kennecott Copper Corporation embarked on a training programme, the same type of programme that had been inaugurated earlier at the •Utah Copper Division at Bingham, Magna, and Garfield, Utah. President Charles Cox of Kennecott, in •a speech made •before the Utah Bankers Association in June of 1951, stated that, ""I think that our programme of employee training is one of the most important phases of our entire operation"". That statement might be said to be one of the guiding principles of training at Nevada Mines Division. Training is supported by top managements and down the line to Division managements. As the years go by, the Company expects to receive many benefits from training."

Jan 1, 1954

By Zoë Mullard

Just as a mine has a lifecycle, employees working within the mining sector also make several transitions throughout their career, from initial recruitment to retirement from the industry. Throughout the employment lifecycle, employees bring skills and knowledge that significantly contribute to the global economy. These skills are developed through education, professional training, coaching and through hands-on experience. Despite the current economic conditions and the demand for minerals, the mining industry is facing a substantial skills shortage due to the disparity between the number of new workers entering the mining industry and a largely ?graying workforce?. Although educational programs continue to evolve to attract people with a wide range of skills, the diversity of jobs and the strains of working in remote mining operations continue to present challenges for recruitment and retention of employees. This gap also presents challenges around knowledge transfer at a corporate and mine-site level; employers will require cultural and techno-sociological approaches to ease through these transitions. At the same time, there has been an explosion of social media tools that facilitate information sharing, cross-organizational collaboration, distance learning and knowledge capture. These tools have become increasingly popular in the last few years and their applications vary widely. The mining sector has started to adopt these tools for a number of purposes, including opportunities to harness social media to enhance human resources interactions, outreach and oversight. This paper will outline several case studies that explore leading practices for how the application of new media can assist organizations and individuals as they progress through their careers. This paper will illustrate how new social media communication technologies can be used to increase employee engagement and build organizational capacity in the mining industry. The paper will also include strategies for how to implement social media to enhance human resources applications and will cover ideas for monitoring and evaluation.

Aug 1, 2013