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By Samuel B. Rombeger

The behavior of gold in hydrothermal systems is evaluated as a function of pH and oxygen and sulphur activities at temperatures to 250°C. Under conditions of stability of pyrite and argillic alteration as emblages, gold will be transported as bisulphide complexes. In systems containing significant amounts of arsenic, thioarsenide complexes may be important. Oxidation, dilution and reduction in sulphur activity would cause gold deposition from saturated solutions under these conditions. Gold chloride complexes will predominate under oxidized conditions where hematite or other oxides are stable and depo ition would result from increase in pH and/or reduction . Absorption and coprecipitation are po sible mechanisms of deposition for gold in certain low grade depo it . Low concentrations of gold in the transporting solution combined with the ignificant solubility of gold as bisulphide complexes, sugge t hydrothermal solutions rarely may be saturated with gold and coprecipitation with sulphides may be an important initial depositional process. Recrystallization of the sulphides in the presence of the hydrothermal solution would be re ponsible for release of gold to more table ite . Thi mechani m i supported by the close association of gold with pyrite in many hydrothermal gold deposits.

Jan 1, 1986

By K. Hambrice, E. Fauveau

"When it comes to measuring the level of bulk solids, liquids, and everything in between, guided-wave radar technology now offers more level-detection capabilities than ever before. For an ever-widening range of previously hard-tomeasure products such as molten sulphur, liquid ammonia and petrochemicals, guided-wave radar transmitters provide accurate level measurements even under harsh chemical environments, wide variations in operating temperatures and pressures, and low dielectric constants.Great strides have been achieved in making these units easier to configure to a variety of process applications coupled with the simplicity of integrating these devices with most digital communication protocols. These improvements come as welcome relief to process engineers within an expanded range of level applications across several different industries that seek solutions to measuring the contents of tanks, silos, hoppers, bins, mixing basins, and vessels.Because radar transmitters have no moving parts, radar has already established a dominant niche in level measuring that quickly distances itself from mechanical means, which do not hold up as well in dirty service. Radar achieves its nonmechanical level detection capability by measuring the time of flight of the transmitted signal.Known more accurately as time domain reflectometry (TDR), the process involves sending microwave energy down into a vessel. When the pulse of radar energy reaches the product (indicated by a change in impedance), part of the pulse is reflected back toward the transmitter.A receiver measures the exact duration of time between the transmitted and reflected signal — the “time of flight.” The device analyzes this time and ultimately displays the level of the product as a distance in feet, metres, or other engineering units."

Jan 1, 2003

By A. Khan, C. Ciriello

The purpose of this paper is to demonstrate the value of constraint modelling in optimization of mineral processing systems. This will be achieved by first understanding the overall concept of variation and constraints present in any system. Next, the value of using a Constraint Model in optimization is demonstrated through comparison of business cases. The benefit of understanding the severity of constraints and movement of the bottleneck within a mineral processing system will be understood through the use of a case study. Paper will conclude with a summary of all optimization benefits that utilization of a constraint model can bring.

Jan 1, 2015

By Ramsey Hart

MiningWatch Canada is the only national independent civil society organization with an exclusive focus on mining in Canada and Canadian mining companies operations internationally. In 2005, MiningWatch Canada collaborated with other NGOs to develop the Framework for Responsible Mining: A Guide to Evolving Standards. The project was the result of a perceived need by NGOs and retailers, particularly from the jewellery sector, for a framework that would set out environmental, social, and governance standards for the minerals sector ?providing recommendations for retailers and others seeking to source or invest responsibly, as well as regulate and encourage responsible mining practices?. This paper is a reflection on the Framework that examines key areas of concern and notes where the industry norms and expectations of civil society have evolved. The paper focuses on developments in social issues related to the UN Guiding Principles on Business and Human Rights, new initiatives associated with financial transparency, the UN Declaration on the Rights of Indigenous Peoples. The environmental components of the Framework that are revisited are waste management, biodiversity, energy and climate change, environmental assessment, mine closure, mercury and seabed mining.

Aug 1, 2013

By C. A. Young, H-H. Huang, L. G. Twidwell

Equilibrium calculational software programs can be effectively utilized to model important parameters in aqueous and aqueous/solid systems, e.g., activity or concentration, solubility, temperature, solution pH, solution potential, and ligand complexation. In this regard, the calculational program ST ABCAL will be demonstrated. Illustrative examples for the creation of diagrams such as potential-pH, and activity or concentration-pH will be presented to demonstrate the fundamentals in real hydrometallurgical systems. Speciation, titration and mixing will be used to simulate or predict operational processes. Berkeley Pit water from a flooded abandoned copper open-pit mine will be used to illustrate the modeling process. According to analytical results the water contains about 20 important constituents. In addition to measured potential and dissolved oxygen, there are two distinctive oxidation/reduction couples. Concentration and other experimental parameters are seldom matched to each other and 12 different conditions have been identified. Water for each condition must be speciated in order to find the best-fit model. The STABCAL program will be used for the modeling calculations and the implication of the water chemistry to defining treatment opportunities will be discussed.

Jan 1, 2005

By Dong-Hyeun Koh, Yun-Soo Lee, Min-Seok Kim, Hyoung-Wook Kim

High strength AA7068 (Al - 7.88 wt.% Zn - 2.68 wt.% Mg - 2.07 wt.% Cu) aluminum alloy strip was successfully fabricated by horizontal-type twin roll casting. A simulation technique was used to obtain the range of casting conditions for fabricating strip without defects. The cast strip with thickness of about 5 mm was hot rolled, intermediate annealed, cold rolled to final thickness and subsequently annealed at various temperatures. Tensile properties of annealed and the aged specimens were evaluated at ambient temperature. Tensile strength and elongation of the annealed sheet are about 365 MPa and 28%, respectively. Also, the tensile and yield strength after the aging at paint baking condition (180 °C x 0.5 h) are 586 MPa and 551 MPa, respectively. Therefore, it is expected to show good formability prior to press or stamping and also provide high dent resistance after paint baking treatment.

Jan 1, 2015

By G. P. Kundargi

India is one of the fastest growing economies in the world. The role of the Iron & Steel industry is very important for the development of the country. Iron and steel are among the most important components required for the infrastructure development of the country. This is one of the fastest growing sectors. The demand drivers for the Indian Iron & Steel industry are increase in the activities of the manufacturing industry and infrastructure development. Indian Iron & Steel industry with its strong forward and backward linkages contributes significantly to overall growth and development of the economy. The industry today directly contributes 2% of India?s Gross Domestic Product and its weightage in the official Index of Industrial Production (IIP) is 6.2%. Manganese is a main ingredient for production of steel. Almost 90% manganese is being utilized by the steel industry worldwide. Globally, there is no substitute for manganese as on date. There is huge gap between demand and production of manganese ore in the country. To meet this demand gap and to support for growth of national economy, MOIL Limited (formerly Manganese Ore India Limited), a Government Enterprises, producing annually around 1.1 million tonnes (mt) of manganese ore and value added products, has geared up with various infrastructural activities to increase the present production capacity of 1.1?1.5 mt in 2016?2017 and 2.2 mt in 2020?2021. The paper deals with the technological improvements and infrastructural development activities of MOIL; this will help MOIL to become the market leader in manganese ore production globally in the coming years.

Aug 1, 2013

By C. S. Chen, Y. J. Luo, M. W. Gao, B. Li, Z. F. Zhang

"To obtain large-sized billets with fine grains and homogeneous elements distribution, uniform direct chill (UDC) casting process, based on annular electromagnetic stirring coupling with intercooling, was employed to produce 7055 alloy billets with a size of F584 mm in this study. The results indicated that there were the coupled effects of annular electromagnetic stirring and intercooling on grain refinement and element homogenization, and also the billets produced by the UDC casting process showed excellent hot workability in comparison to the normal direct chill casting process.INTRODUCTION The high solute 7055 aluminium alloy has a wonderful combination of high specific strength and hardness, good resistance to stress corrosion cracking and high fracture toughness, which is very useful in aerospace application (Yan et al., 2013; Mondal & Mukhopadhyay, 2005). The production of large-sized 7055 alloy billets with high quality is the basic condition for the subsequent application of 7055 alloy to the aircraft. Inhomogeneous microstructures and performances of 7055 billets result from the high alloying element content and the inhomogeneous cooling condition in different regions of billets during the conventional direct chill casting (Paramatmuni et al., 2004; Lalpoor et al., 2011), which will bring bad influence to processing property, functional performance and utilization rate of materials. To alleviate segregation and obtain fine and uniform grains, some effective treatment methods were proposed including electromagnetic stirring (EMS) (Vives, 1989), ultrasonic vibrating (Zhang et al., 2011) and melt conditioning (Fan et al., 2013), on the melt to obtain fine and uniform grains. However, these methods could not effectively decrease the large temperature difference between central and periphery parts of the billet, because the solidification mainly depends on outside cooling including mould cooling and water spraying cooling. To change the heat extraction pattern of the billet functioned solely from the outer surface, based on annular electromagnetic stirring (A-EMS) invented by Xu et al. (2010), Luo et al. (2017) proposed uniform direct chill (UDC) casting coupling A-EMS with intercooling in the direct chill (DC) casting process. An in-mold cooler was inserted to the melt sump, and thus the alloy melt temperature and concentration at solidification front become more uniform."

Jan 1, 2018

By M. Sommerfeld, U. Schwarz-Schampera, B. Friedrich, D. Friedmann

The steadily growing demand for metals and their price increase at metal exchanges make the mining and utilization of marine mineral resources like polymetallic nodules, manganese crusts or sulfide deposits in the near future a viable option to potentially increase the supply of base and precious metals. For a country with low potential to mine land-based resources like Germany, the industrial recovery of metals from marine mineral resources could lead to a decreased dependency on imports. In this study, seafloor massive sulfides from the German license area in the Indian Ocean (Kairei field, Southern Central Indian Ridge) are treated to recover copper and precious metals. The aim of the project is to demonstrate the transferability of existing metallurgical techniques to the raw material of deep-sea massive sulfides. As a starting point to process this unconventional resource, samples from the Indian Ocean are chemically analyzed and mineralogical characterized. A comparison is carried out between the samples and land-based copper resources, to highlight the potential which lies in mining the deep-sea floor. This paper will show the general possibility of applying a two-stage pyrometallurgical process, based on a concentrate smelting operation, followed by a converting operation in lab-scale to the provided samples of massive sulfides. Generated slag from the concentrate smelting and the converting operation are investigated by X-ray diffraction to determine the mineralogical composition. The two-stage pyrometallurgical process is investigated by the thermochemical modelling tool FactSageTM 7.2 to evaluate the phase distribution of relevant elements between the metal, matte, slag and gas phase. The thermochemical boundaries of the pyrometallurgical process are therefore set and the results of the thermochemical study can be used as an indicator for the efficiency of an up-scaled process and the generated amount of side-streams, which need to be further treated or circulated back into the process. INTRODUCTION Seafloor massive sulfides (SMS) are the third kind of discovered deep-sea minerals besides ferromanganese nodules and cobalt-rich ferromanganese crusts (Sharma, 2017). They occur in water depths around 250–4,000 m (Koschinsky et al., 2018). SMS are characterized by a high base metal and sulfide content. They were created by fluid circulation and hydrothermal convection over time (Han et al., 2018). Commonly, areas rich in SMS are associated with hydrothermal vent fields on the seafloor (Keith et al., 2018).

Jan 1, 2019

By C. J. Newman, D. J. Kemp, R. M. Sweetin

"The smelter is described by area; feed preparation, continuous furnace line, gas handling and auxiliary systems, blister refining, Hazelett casting of thin anodes, and scrap remelting. Early smelter campaign data is presented and compared to design. Some modifications to the basic design of the furnaces and gas trains are indicated, with their respective impacts on improving smelter performance.Plant compactness, the use of jumbo tanks, and a highly automated electrode handling system are featured in the refinery description, with brief coverage of the liberator and slimes leaching sections. Early experience in refining thin regular Hazelett anodes, and submersible pump recovery of raw slimes are relayed, together with automatic stripping from titanium blanks.Refinery tonnages and operating parameters are given showing the relatively trouble-free attainment of refinery design performance.IntroductionPrevious papers and articles ( 1), (2) ,(3 ) have described the metallurgical facilities serving the copper-zinc-silver Kidd Creek orebody located near Timmins, Ontario. For convenience a brief review of their mid-1983 operating status is presented.The concentrator, originally designed for 9,000 short tons, was commissioned in late 1966. It can now comfortably process over 13,000 metric tonnes per day largely as a result of the addition of a fourth circuit in 1978."

Jan 1, 1984

By Mario Gerards, Axel Wellendorf, Arulnesan Rajesh

"In times of increasing energy cost and global demand for improved machine technology, the optimization of industrial mineral processes in terms of efficiency and production cost is an important factor when choosing industrial equipment suppliers. Of course this applies for screening machines, feeders and distributers as well!Besides of the ability of a screening machine for being adjustable to changing requirements during the production process itself, it becomes more and more important to choose the correct screening machine type, peripheral equipment for arising screening tasks and to optimize the overall design of the screening machine starting at a very early stage.The different types of screening machines bring many advantages and disadvantages with them. The selection of the correct type of screening machine can improve the flow rate, energy, efficiency, yield, quality, output, availability and decrease the maintenance costs and structural steel work.The machine optimization has to be a consecutive process in which at any time results of simulation and “real-life measurement” are compared and the findings are implemented in machine development and design. As an example, it is possible to reduce machine weight and reinforce the steel structure of a screening machine at the same time, which enables the manufacturer to use smaller drives for the screen.This paper will present the methods ANSYS and 3D Solid Works used at RHEWUM GmbH for this way of optimizing machine design and construction and examples for results gained from this continuous improvement process."

Jan 1, 2016

By G. Kallfa P. Geo

Exploration at both Greenfields and Brownfields stages entails business risks of different nature and success rates. Greenfields exploration is exceedingly assumptive and the success rate of exploration or return on investment is low because exploration is an inherently risky business. Brownfields exploration on the other hand is less risky, as the geology is better understood, but generally speaking since the larger ore bodies close to surface have already been found the return is lower. In addition, most exploration at the Brownfields stage is generally more expensive due to extensive use of drilling. Surface geology mapping and expensive drilling have been key technical contributors to most exploration programs over the last two decades. However, as client expectations, logistics, target depths and complexity of exploration programs increase, there has been a growing emphasis on using geophysical techniques to complement other methods. Integration and optimization of various geoscientific disciplines is becoming more important in successful exploration programs of the future to reduce exploration risks, successful integrated exploration requires putting reliable geophysical parameters and correspondent petrophysical property contrasts into an assumed or conceptual geological model. This paper discusses a new multi-parameter geophysical methodology finalized in a unique conceptual geologic model which can be used either as a root model in grassroots exploration or as an efficient tool in Brownfields exploration to successfully find satellite orebodies of almost any size. The application of a new multi-parametric geophysical approach to Brownfields exploration is illustrated with examples from Manitoba, including a past producing nickel sulphide deposit in Lynn Lake and the Reed Copper deposit, currently in development.

May 1, 2013

By Joseph D. Martinez

"The benefits of modern technology can readily be identified with energy availability. A clear correlation has been established between per-capita energy consumption and the GNP for various nations. The United States is an outstanding example of a nation which has benefited from vast energy reserves. The nation is now challenged, how¬ever, by dwindling reserves and the need to develop new sources consistent with the preservation of environmental quality. The development of new, virtually inexhaustible and environmentally acceptable sources cannot be expected for several decades. Meanwhile, we will have to depend on coal, nuclear energy and/or rigorous conservation measures.The net effect of environmental considerations has been to delay and perhaps ultimately eliminate the nuclear energy option as a national energy alternative. This forces a more positive move toward coal as the next major source of electrical power. Our coal resources are large, but the use and production of coal is also a threat to the environment. Thus, we seem to be moving from one major accessible source to another due to environmental concern only to face the probability that the alternative is also environ¬mentally unacceptable.Controversies revolving about energy choices must be resolved by an analysis of the relative benefits and impacts of these two sources and others. The pattern of changing energy sources is not new. We have moved from wood to coal to oil and gas in the past and must learn to adapt in the future. Rational decisions must be made relative to the utilization of intermediate energy sources pending development of promising future approaches. A collapse of current levels of energy supply could threaten our technological society and the means to develop a new energy base."

Jan 1, 1976

By Hugh S. Spence

This paper deals with an occurrence of radium ore near Wilberforce, Haliburton county, Ontario, upon which development work has recently been undertaken and which seems more likely to prove of commercial grade than any other deposit' of radioactive minerals hitherto found in Canada. This occurrence is sometimes called the Richardson property, after Mr. W. M. Richardson, the discoverer, and will be so referred to in the present paper. Occurrences of radioactive minerals are not uncommon in eastern Canada, and a number are recorded in the literature. The earliest of such references is probably that in Geology of Canada, 1863, where is mentioned an occurrence of uraninite at Mamainse, on the east shore of lake Superior. The mineral was first described by J. L. Leconte, in 1847, under the name of coracite, and was said to occur in a two-inch vein at the contact of trap and syenite. Search for this locality in recent years has proved unsuccessful. Obalski, in 1894, mentions (1) the occurrence of uraninite at a mica mine near Murray Bay, Que. In 1903, Obalski records (2) tests made on this uraninite by Rutherford and the Curies and the determination in it of the then newly-discovered element radium. In 1901, he mentions (3) the occurrence of uraninite at the Villeneuve mica mine, on the Lievre river, and of samarskite at the Maisonneuve mica mine, in Berthier county.

Jan 1, 1930

By Graham Walker

A new Code of Practice for the brake performance of off -highway vehicles was established in Alberta in 1976. Vehicles loaded to gross vehicle weight must be capable of stopping with mechanical brakes five times in quick succession on a grade of 10 per cent from a speed of 28 miles per hour. Comparative trials of various brake systems have been carried out and some combinations capable of meeting the Code are identified. Some problem areas in truck braking are reviewed and potential developments indicated.

Jan 1, 1977

By S. G. Luckey, N. R. Harrison, F. Nadeau, U. Brüx

"The adoption of tailored-rolled or tailor-welded blanks (i.e. TRB/TWB) in the automotive industry has been known to offer great potential for the optimization of weight, function, cost and complexity. Vehicle light weighting can further be achieved by using high strength aluminum alloys like the 7xxx-series. 7xxx-series alloys are capable of delivering specific strengths equal to or greater than high strength steels. However, room temperature formability of this aluminum class is limited, so one approach to forming 7xxx-series alloys is by hot stamping. Hot stamping utilizes an elevated temperature blank and the high pressure stamping contact of the forming die to simultaneously quench and form the sheet. This paper explores the initial feasibility of tailored thickness material for body-in-white applications when processed under hot stamping conditions.INTRODUCTION Steel tailor-rolled blanks (TRB) or tailor-welded blanks (TWB) have been used within the automotive industry as a method of reducing weight, expanding material utilization, and decreasing overall part/assembly cost (Ganeasan et al., 2015; Merklein et al., 2014; Hirt et al., 2005; Kridli et al., 2000). The production of such tailored thickness materials has resulted in over $2.5 billion (2016) in combined industry sales (Mubea, 2018). As automakers begin to adopt the manufacturing practices traditionally reserved for steel such as tailor rolling/welding with greater enthusiasm for vehicle light weighting, there exist an opportunity to expand the material database to extend beyond the traditional aluminum alloys found in current production. High strength aluminum alloys, i.e. 7xxx-series, are ideal for structural automotive applications due to their high specific strength; however, they have limited room temperature formability. Hot stamping, another manufacturing practice used by the steel industry, can be used to form these high strength materials. The combination of tailoring the thickness of a sheet material and hot stamping provides an opportunity for significant weight saving within an existing manufacturing footprint. This paper explores the potential and challenges of this approach when applied to structural body-in-white components. The methods for tailor rolling, tailor welding and hot stamping are described and applied to the production of a 7075 aluminum alloy B-pillar. The results are discussed in terms of feasibility and weight savings."

Jan 1, 2018

Cominco began investigations about ten years ago relative to noise abatement in underground operations. As a result of intensive research, this study has advanced so that the practice now has wide application. Automotive mufflers are used on vane-type blasthole diamond drills. Exhaust hoses are attached to longhole percussion drills. Hand-held drills, such as airlegs and stopers, are equipped with mufflers which are either part of the drill, as received from the manufacturer, or are light rubber de-vices developed, fabricated and installed by Cominco. Ear defenders are in general use. The paper reviews details of practices employed, and assesses the success achieved. Noise is generally associated with some of the basic equipment used in mining. About ten years ago, in order to improve on this situation. The Consolidated Mining and Smelting Company of Canada Limited began investigations relative to noise abatement in its underground operations. As a result of intensive research, this study has advanced to the point

Jan 1, 1964

By J. E. Reeves, J H. Morgan

Certain non-metallic minerals are used widely as fillers in the manufacture of many Canadian products. The first part of this paper deals in a general way with deposits of such minerals and their mining, with the concentration and preparation of the minerals for market, with specifications of the consumers, and with methods of control of the products to meet the specifications. The second part of the paper de-scribes talc as a specific example of mineral filler. Its production and uses in Canada and the possibility of producing higher grades of talc are discussed. Some suggestions are made for meeting the needs for mineral fillers as Canada's industry expands. RELATIVELY few people are sufficiently aware of the vast and important role that is being played in our everyday lives by mineral fillers. Many kinds of paints, papers and plastics, to mention three major classes of industrial products, are literally loaded

Jan 1, 1961

By A Falter

Gyroscopic surveying instruments, which apply the physical law of a gyroscope, are being used for deter-mining the azimuth of lines with a high degree of ac-curacy. In the past ten years, gyro-theodolites have been introduced widely for underground orientation in the mining industry of Russia, Germany and South Africa. Gyroscorpic methods eliminate awkward procedures of conventional shaft plumbing, and provide more safety, excellent control and the highest precision at any point under-ground without interference with hoisting operations. The advantages of gyroscopic orientation in geodetic surveys become obvious in primary and secondary triangulation, in the determination of co-ordinates of single triangulation points, using the method of trigonometric re-section and intersection, and when traversing over long distances or in areas with obstructed view. Other fields of application are found in geophysical surveys and in the orientation of technical objects; e.g. radar stations, relay stations and ballistic missiles.

Jan 1, 1964

By Staff, G. M. Hogg

"The eastern portion of the Late Precambrian geosynclinal structure known as the Labrador Trough comprises a 16,000-square-mile sulphide-bearing belt of good potential as a base metal exploration area. Hollinger and Hanna mining interests have carried on exploration in the region since 1953, with encouraging results. This program has been considerable in terms of both effort and expenditure, and has resulted in an apparently successful primary evaluation of the entire belt.Much detailed work remains to be done in the area. Exploration to date has been largely of a reconnaissance nature, employing various methods in common use in Canada today. In the course of this work, several deposits of promise, containing near-economic quantities of copper, zinc, nickel and other metals, have been located. A broad classification of these deposits is proposed.Exploration in the sulphide belt was started on the basis of partial control of the area under mineral exploration concessions. This was necessary to justify operations in an area of difficult access and high operating costs. The results of this now-terminated arrangement are regarded as being of benefit to those directly concerned as well as to the mineral industry in general."

Jan 1, 1966