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By A. W. Jolliffe

DESPITE the widespread occurrence of scheelite in Canada, domestic production of this strategic mineral is still quite insufficient to meet wartime needs. Two difficulties have invariably arisen in prospecting for or developing scheelite deposits: scheelite is a difficult mineral to identify, and secondly, its distribution is commonly so erratic that the value of a deposit cannot be determined without arduous and expensive methods of sampling and wet assay. Scheelite's property of fluorescing under certain ultra-violet lamps overcomes the first difficulty and is the basis for a quantitative method developed to overcome the second. It is found that, by use of an ultra-violet lamp, the value of many scheelite deposits may be accurately and speedily determined. The method requires neither elaborate apparatus nor exceptional skill on the part of the operator, and is most applicable to those deposits where the bulk of the scheelite occurs in fairly pure aggregates that are at least one-tenth of an inch across. It has been used in grading some two hundred scheelite-bearing veins in the Yellow-knife-Beaulieu region, Northwest Territories, and various occurrences in the Porcupine district, Ontario. The method requires the measurement of the total area of scheelite exposed in any reasonably large measured cross-section of a deposit. From the areal percent of scheelite so obtained, the tungstic oxide (WO,) content of that part of the deposit may be calculated by means of equations of simple derivation.

Jan 1, 1942

By J. A. Hudson

"The paper begins with a brief summary of Professor Müller’s formation of the ISRM and the contents of the previous six Müller lectures with their emphases on rock fractures. The geological origin of fractures is described via a deformational spectrum diagram and a matrix characterising the consequences of a sequence of superimposed deformational events. The different fracture frequencies encountered along lines in all directions through a fractured rock mass are explained. The value of computer modelling and simulation is demonstrated through an example of the effects of fracture zones on the distribution of the in situ stress field. The need to establish the validity of computer programs, i.e., that the modelling/simulation, does actually represent the rock reality, is discussed with reference to the work of the DECOVALEX project. Finally, examples are given of the effects of rock fractures on engineering design and construction, from pre-split blasting to caverns.INTRODUCTIONIt is a great honour to have been chosen as the recipient of the ISRM 7th Müller Award and I am grateful to the representatives of the International Society for Rock Mechanics (ISRM) National Groups who voted for me. In addition, I am especially pleased because my working life in rock mechanics and rock engineering has been devoted to understanding the geometry and mechanical properties of rock fractures and rock masses—which were the key subjects that Professor Müller promoted. In the ISRM 50th Anniversary Commemorative Book, Hudson and Lamas (2012), Professor Charles Fairhurst notes that on 24 May 1962, i.e., the day before the constitutional meeting of the ISRM took place in Salzburg, a reporter asked Professor Müller, “Do we know the strength of rock?”, to which Professor Müller replied, “For rock tested in the laboratory, yes. For a rock mass, no. This is what we need to determine. This is why we need an International Society for Rock Mechanics”. Also, in his Opening Address at the 1st ISRM Congress in Lisbon, Professor Müller, as the then ISRM President stated,“Many experts agree with me that discontinuity and anisotropy are the most characteristic properties of the material rock and that the properties of jointed media depend much more upon the fabrics bond of the unit rock block system than upon the rock material. Therefore any theoretical investigation of that material has to go its own ways, in the same way as the construction material of soils years ago suggested to soil mechanics its own methods, which differ greatly from the way of thinking of technical mechanics”."

Jan 1, 2015

By Vahid Faghihi

SatraPM is a web-based software package, aiming to help project managers to easily handle their construction projects via internet. This software is capable of handling all projects of an organization, in which all projects can be defined in EPS the same as users in OBS. A 3D accessing module links EPS, OBS and inherent functions in order to provide a secure environment for the data to be processed throughout the system. This paper intends to take a deeper look at capabilities of SatraPM in helping project managers to keep track of and control their construction projects as well as its potential future features.

Aug 1, 2013

By Arthur Notman

In view of the alarm expressed in many quarters over the increased production of copper to come from Canada and Africa in the future, it is of interest to study the history of the principal producing districts of the world and to attempt to forecast the future part to be played by them. Tables 1 and 2 record the world production and that of the United States, together with their respective rates of increase, both in percentage and actual amounts. The important point in this record is the decline in rates of increase for both the world and the United States, but more particularly in that of the latter, since 1881. The increase for the United States in the last decade is less than that for any decade since 1881, and is only 20 per cent of that for the decade 1911-20. The increase for the world is less than that for the two preceding decades, and is only about 65 per cent of the war decade 1911-20. Referring to Table 1, the decade 1871to1880 showed an increase of 32.l per cent in the world's production, which was the low until the last decade, ending 1930, which shows an increase of only 24.5 per cent. These decades both represent periods of economic stress following wars. In the first case the recovery was very sharp, the percentage increase in 1881-90 reaching a high of 86.4 per cent. It would seem dangerous, however, to assume that a similar high will be reached in the next ten years, because of the severity of the depression brought about by the Great War and the probability of its influence extending well into the next decade.

Jan 1, 1931

By Ed Labelle, Terry Overton, Gary Bell

"LocationThe Miller Minerals lime and limestone production facility is located in the Temiskaming district of Ontario at Hailey bury on the west shore of Lake Temiskaming. Located less than 300 km from Sudbury, Timmins, Rouyn-Noranda and Val d'Or, the plant is very well situated to market products to the mining, pulp and paper, and environmental industries. Being located a few kilometres from the Trans-Canada Highway and the Ontario Northland Railway adds to transportation efficiencies.ProductsAt Miller Minerals, two principal products in various sizes are produced, which are limestone (CaC03) and quicklime (CaO).HistoryProduction of limestone products began in 1979 at this quarry site. During the 1980s, limestone products were marketed to a variety of applications for mining, forestry, environmental and agriculture applications. In 1990, the production of quicklime products began, following the commissioning of an Italian-designed vertical shaft calcining plant. During the 1990s, both quicklime and limestone products were produced to meet the customers' demands.From the quarry's conception until 1992, the operation was owned and operated by Dymond Clay Products. In 1992, it was purchased by Miller Paving Ltd. of Markham, Ontario, and became a key part of the company's industrial minerals sector of business. Other Miller interests include dolomite, cement, paving materials and waste management."

Jan 1, 2000

By S. Pauly, U. Kühn, J. Eckert, I. Kaban, G. Wiehl, F. Silze

In the present work, the effect of Ga on the wetting behavior of the Cu-rich braze filler CuGa10 (wt.%) on the steel 304L was investigated. For this, the macroscopic and microscopic effects governing the wetting of pure Ga, pure Cu and CuGa10 alloy (wt.%) on the austenitic steel were analyzed and compared. Contact angle and surface tension measurements were carried out by means of the sessile drop technique and, in addition, the phase formation at the interface was determined. Pure liquid Ga spreads on 304L, which supposedly is related to the formation of intermetallic Fe-Ga phases growing into the liquid Ga. Depending on the annealing time, FeGa3 and Fe14.5Ga12 were identified. In contrast, CuGa10 as well as pure Cu show secondary wetting on the steel surface. Especially, liquid Cu prefers to spread laterally and vertically along the grain boundaries of the steel substrate. In spite of rather similar mechanisms, CuGa10 wets 304L steel at lower rate than pure Cu above the liquidus temperature.

Jan 1, 2014

By B. Zhu

With the challenge of clearing steel production and increasing of the productivity of converter, the application of hot metal pretreatment technology in torpedo car become a key process in the steelmaking. In this article, the technologies, production and development trend of Al2O3-SiC-C bricks for torpedo cars in China are reviewed, the current application situation and main requirements for the Al2O3-SiC-C bricks are also addressed.

Jan 1, 2004

By Z. Y. Ma, H. Y. Yang

The process of microwave-ultrasound assisted leaching of valuable metals from copper anode slime was proposed in this paper. Design of experiments has been used to study the effect of the main leaching parameters, such as microwave power, ultrasound power and reaction time. The central composite design (CCD) was used to predict the maximum leaching efficiency of copper, tellurium and selenium. The experimental data obtained were fitted to a second-order polynomial equation, and they also were analyzed by analysis of variance (ANOVA). The 3-D response surface plots and the contour plots were applied to determine the optimal conditions. The optimum conditions of microwave-ultrasound assisted leaching process were: microwave power 834W, ultrasonic power 638W and reaction time 403s. Under these conditions, the experimental leaching efficiency of copper, tellurium and selenium were 98.88±0.56% 98.96±0.78% and 98.57±0.67%, respectively, which agreed well with the predicted values.

Jan 1, 2014

By G. Bonin, R. P. Preston

"This paper presents a series of case studies where spherical camera photographs were used to generate 3D shaft models using photogrammetric methods. The shaft models were, checked for accuracy by comparing them to overlapping laser scan data, provided survey data or idealized shaft models. Short lengths of model were found to more accurately reproduce the shaft surface, with a best observed accuracy of 8 mm. Longer models encountered errors with accumulated errors as exhibited by slight deviations from vertical or slightly conical model shape. At present, the models are considered acceptable for general documentation and gross change detection. INTRODUCTION Shaft inspections are required by mining regulations in many jurisdictions and are commonly completed by trained mine personnel via visual inspections. This can be time consuming and prone to errors due to lapses in attention and the rapid travel rate required to inspect an entire shaft in a reasonable amount of time. Similarly, because of the time requirements, there can be impacts on other aspects of mining as a result of occupying the shaft for inspections. Spherical cameras with supplemental light systems offer a modern addition or alternative to conventional inspections. These cameras can be lowered relatively quickly to collect high definition, fully illuminated videos of the shaft that can be reviewed in detail later while the shaft returns to service (Gillis et.al., 2019). The use of cameras offers a further opportunity for valuable survey data generation from the same original data stream. The video data can be processed into three-dimensional (3D) models using Structure-from-Motion (Westoby et al., 2012) based photogrammetric methods. Depending on the quality of the source video and availability of survey control (required for all photogrammetry models) these models can be very accurate. Shaft surveying can be conducted with traditional theodolite methods but such surveys are time consuming and limited in their data density. Similarly, scans can be completed using conventional terrestrial laser scanners, but this requires a significant number of distinct setups to provide sufficient overlap between scans. Work is being conducted both on the laser scanning (SLAM, Durrant-Whyte & Bailey, 2006) and photogrammetry fronts towards kinetic scanning (Benecke, 2017) systems. The major advancement which is permitting these kinetic systems is Inertial Measurement Units (IMUs) which can provide localization in GPS denied environments and reduce errors associated with the open traverse format associated with shaft scanning."

Jan 1, 2019

By A. Taylor

This paper considers mineral processing in zero gravity dry environments typical of asteroids or comets. The electro-dynamic separation technique using pneumatic flow systems is explored. Pneumatic delivery of solids is used because of extreme temperature changes and the possible scarcity of water. The present earth-based process and how it can be modified for these conditions is examined.

May 1, 2001

By A. A. Brant

Self-potential methods are based ?on measurements on the surface of voltage distributions caused by natural sub-surface oxidation phenomena. The attempt is made to. correlate voltage minima or maxima with the location of mineral materials or geological conditions which may give rise to such naturally produced spontaneous potentials. Any orebody undergoing oxidation is a source of electric current. Ground waters carrying free oxygen attack the upper surface of the body, rendering this the positive pole of a galvanic cell, with the lower portion of the body the negative pole and the surrounding weak acidic waters the electrolyte. Current flow is from positive to negative through the orebody and negative to positive through the electrolyte, i.e., through the surrounding rock. The upper end of a steeply dipping, tabular orebody is hence indicated as lying below the point on the surface where the largest negative potential is observed(l). From its basis, it is apparent that the self-potential method was developed primarily for ore exploration.

Jan 1, 1942

By H. P. Whaley

This paper introduces Wabush Mines, including its ownership, physical assets, capacity, goals and achievements. It is to be followed by four papers which will present the detailed story. Wabush Mines, the largest supplier of iron ore to the Canadian steel industry, was brought into production in 1965. The ore is mined and concentrated in Wabush, Labrador, Newfoundland and pelletized at Pte. Noire, Quebec. Annual capacity is over 6,000,000 tons of high-grade iron ore pellets.

Jan 1, 1969

By J. Paquin, P. Doiron, G. Proulx, P. Champoux

After nine years on a 36 hour schedule and two programs of creeping, the Alcoa Deschambault Potroom of faced the necessity of changing its organization for many reasons: the anodes butts were too small, the anode schedule was unbalanced, the iron content in the metal trends had increased, the metal tapping volume did not convene with crucible capacity and the liquid measurement task was delayed by tapping activities. A kaizen activity inspired the Potroom department to improve the organization. A team of 15 people including the process engineer, the process technician, team supervisors and Potroom operators developed a scenario, which would permit flexibility to creep pots if energy is available and an increase of added value production.This paper will describe the systematic approach, the communication method, the trials, the changes, and our success, along with the problems experienced by the team during the adaptation of Alcoa Deschambault Potroom organization over a 20 month period. Aluminium 2006 45th Annual Conference of Metallurgists ofCIM Montreal, Quebec, Canada Edited by

Jan 1, 2006

By A. Roy, T. LeBel, P. Coursol, P. Lind

At the early stage of a mining project, small amounts of concentrates are available for testwork. For gold concentrate or ores containing significant arsenic levels, batch bench scale roasting is often unreliable, leading to highly variable gold recoveries to be used in the project’s financial justifications. With an appropriate bench scale unit using continuous feeding and residence time control for solid and gas phases, reliable numbers can be obtained at small scale with only a few hundred grams per test condition. This paper describes the development of a pilot fluid bed roasting unit by Kingston Process Metallurgy Inc. (KPM) to perform representative trials on gold concentrates containing arsenopyrite, arsenian pyrite and carbonaceous components. Calcines produced under different conditions were characterised by chemical analysis and electron microprobe; the calcine microstructure obtained is described. The most important parameter affecting gold recovery is oxygen content in the roasting atmosphere, with the lowest controlled oxygen level giving the highest gold recoveries. Higher local temperatures in the bed may cause the formation of molten glassy phases which can also reduce the gold recoveries significantly. The impact of roasting conditions in the two inch fluid bed is compared with commercial results obtained in full scale operation.

Jan 1, 2014

By W. H. MacLean, S. Liaghat

The Key Tuffite is a thick (0.3 m to 6 m) and laterally extensive (-10 km) cherty, sulfide-bearing tuff unit in Archean greenstones in the Matagami mining district in northwestern Quebec. It lies at the contact of the Watson Lake Group and overlying Wabassee Group volcanic rocks, and is host to major Zn-Cu volcanogenic massive sulfide deposits. The tuff component is highly altered and its volcanic precursors are not identifiable by petrographic means. The tuff is mixed with a volcanic exhalative component comprising chert, carbonate and sulfides (pyrite, pyrrhotite, and minor sphalerite and chalcopyrite). The normative mineral composition of the Key Tuffite is 33% quartz, 28% sulfides, 16% sericite, 8070 carbonate, 6% chlorite and 9% other minerals. In the vicinity of the Bell Allard and Orchan mines, the precursor tuff components are identified using immobile major and trace elements, as Watson Lake tholeiitic rhyolite (Zr/Y = 1.5 to 3.5, LaN/ybN = 1.7 to 2.8, SiO2 = 72.5 ± 1.2 wt %, and Wabassee calc-alkaline andesite (Zr/Y = 9, LaN/YbN= 4 to 8, SiO2 = 56% to 65%). Immobile element computation techniques were used to calculate mass additions and losses in the conversion of the tuff to the Key Tuffite. Average net amounts of FeP3 (27% total iron), Si02 (14%), Cao (8%), S and K2 (+ 2%), were added, Nap was removed (-2.8%), and MgO was over-all unchanged. Total net mass change was +63%, which comprises mainly exhalative additions, but also includes changes owing to hydrothermal alteration of the tuff component.

Jan 1, 1992

By E. Thune, F. Stålesen, E. O. Stensholt, O. M. Dotterud, E. E. Henriksen, P. O. Ramsdal

"The development and commercial operation of the Falconbridge chlorine leach process have been described in papers in 1985 and 1987. Since this time, various process improvements have been implemented and the capacity of the Kristiansand refinery has been increased to 85 000 t/y Ni, 40 0000 t/y Cu and 4500 t/y Co. The focus has been on continuous improvements in productivity, the use of energy and other costs. Several environmental issues have also been eliminated or reduced since 1987. IntroductionThe first nickel refining operation in Kristiansand, Norway, started in 1910 based upon raw materials from Norwegian mines. In 1929, Falconbridge Nickel mines purchased the refinery to acquire information and the patent rights to the Hybinette refining process that was practised at the small Kristiansand refinery. Falconbridge ownership has now, for more than 70 years, provided a strong base regarding raw material supply, financial resources and technical support for further expansions and major technical improvements at the refinery.The main concepts of the new chlorine leach process were developed in the laboratories from 1966 to 1969 and the process was piloted from 1970 to 1972. The main stages in the commercial plant were started in the 1975 to 1981 period. After 1981, there have been a number of process modifications, plant expansions and improvements to operating practices. The developments up to 1988 have been described in previous publications (Stensholt et al., 1986, 1988).This paper presents an overview of the process and how it is practised at Falconbridge Nikkelverk AS (FNA) today and describes some of the main changes that have been implemented since 1988. During this time, the nickel capacity has been expanded from 54 000 t/y to 85 000 t/y and the cobalt capacity from 2000 t/y to 4500 t/y. The paper describes how these expansions were achieved together with continuous improvements in operating efficiency and also gives an overview of the main environmental concerns at the refinery."

Jan 1, 2001

By P. R. G. Brandão, E. E. Ferreira

The presence of metallic cations in solution will affect the aggregation or dispersion of the fine hematite particles, depending on the type of cation adsorption: either specific or non specific adsorption. In this work, the zeta potential measurements were carried out on a sample of pure hematite as a function of pH and metallic cations concentration (Ca2, Mg2+, Mn2+, K+, Na+ and Al3+). The objective of these studies was to clarify the effect of these metallic cations on the surface chemical properties of pure hematite. The cations K+ and Na+ adsorbed as non-specific species and caused only the reduction on the values of zeta potential (in terms of absolute value) over the entire range of pH values tested. For the Al3+ cation, in the acidic pH range it adsorbed as a specific species and increased the zeta potential values. The cations Ca2+, Mg2+ and Mn2+, adsorbed as a non specific species at pH levels less than 6.0 and caused the reduction of zeta potential due to the compression of the electrical double layer. However, for pH values greater than 6.0, these cations adsorbed as a specific species causing the zeta potential to increase and became more positive as the pH value increased (alkaline). This effect could be due to the adsorption of some hidroxy complex species of these cations, which contributed to the positive charge. The effect of metallic cations (Ca2+, Mg2+ and Al3+ concentration, at pH 4.0, 7.0 and 10, showed the following results: a) at pH 4.0, increasing the concentrations of Ca2+ and Mg2+ resulted in on a small reduction in the value of the zeta potential. At this pH, increasing the concentration of A131 cations caused the zeta potential to increase due to specific adsorption of a negatively charged Al3+ hydroxy complex b) at pH 7 and 10, increasing the concentrations of Ca2+ and Mg2+ caused the zeta potential to change its charge from negative to positive.

Jan 1, 2004

By Vishal Shukla, Prateek Singh, D. P. Chakraborty

"Continuous thickening by an operation called sedimentation is the separation of suspended solid particles from a liquid stream by gravity settling. The primary purpose of thickening is to increase the solids concentration of the feed stream. High rate thickeners are designed specifically to maximise the flocculation efficiency. A detailed investigation has been carried out to understand the influence of ore type and operating parameters such as bed level, bed mass, rake arm torque and flocculent concentration on thickening operation. Tata steel’s Noamundi plant data shows that variation in ore type, and operating parameters are major contributors to fluctuation in thickener performance. A lot of research has been done earlier on thickening operation but effect of ore type and operating variables by using plant data was never touched before.In this context, the performance of thickener was evaluated by daily data to study the influence of ore type and operating variables on thickener operation. Investigation shows that friable ore % in feed mix is proportional to slime density because friable ore is porous & brittle in nature. As a result, friable ore generates more fines/ultrafine during communition process in wash plant. Increase in flocculant concentration and bed mass is showing a positive change on high rate thickener performance Investigation shows that optimum bed mass and flocculant concentration is required to achieve desired pulp density in thickener underflow at different feed pulp density (g/cc).INTRODUCTIONOver the years, Iron Ore Beneficiation at Tata Steel, Noamundi has seen varied changes. Depletion of high grade iron and with increasing iron ore throughputs coupled with lowering of the hard ore a subsequent increase in slime generation, slime management and clear water requirement for wet Plant has thrown up myriad challenges. To overcome these challenges, many improvements initiatives were taken by Tata Steel in last decade. One of the major changes is the recent High Rate Thickener commissioning at Tata Steel Noamundi to cater the high iron ore throughput requirement. Slime reporting to Thickener has increased from 1.4 MTPA 2.5 MTPA over the last few decades. The above changes further aggravate the poor settling and dewatering characteristics of the slurry which is being feed to HRT. Considering the above mentioned constraints and stringent environmental implication proper water management has become a major challenge to reckon with. The thickener is used to increase the concentration of the suspension by sedimentation, accompanied by the formation of a clear liquid. In most cases the concentration of the suspension is high and hindered settling takes place."

Jan 1, 2016

By PAUL L. DEAN

Industrial mineral deposits are widespread in Newfoundland and Labrador and a variety of commodities are produced. The province has the only pyrophyllite mine in Canada and also produces asbestos, gypsum, silica, barite, limestone, gemstones, cement and other structural materials. Large reserves of these and other industrial minerals are known and several deposits are likely future producers. Most producers are wellestablished and have large tonnages of ore reserves.

Jan 1, 1984

By A. Valdivieso

Reducing accident rates keeps getting more and more complex as the usual tools enter a curve of diminishing results. Fortunately, nothing modifies behaviour in a stronger and wider way than having a robust safety culture. On the other hand, managing cultural change is difficult and the risk of back-fire is very high, especially if the workforce does not trust our intentions. A personalized approach of well chosen and targeted actions tends to be the only yet difficult option. We have found, via experience in the metallurgy and chemistry industries, a way of preparing the company and the workforce to accept these sorts of culture changing measures faster and easier. Using company-wide changes based on workplace perception, yields the most optimal acceptance. It is based in the principle that we all use clues in our environment as guides to choose our behaviour. So, controlling the perception that our workplace generates can affect behaviour and simplify our task before it even starts. It is a matter of using the tools that other disciplines such as marketing, social engineering and architecture bring to us and adapting them to a very defined objective: Having our installations “sell” safety so that our people unconsciously believe that they must adapt to safety values in order to “do well” in said environment. INTRODUCTION After decades of improvements in accident rates, we are understandably hitting a diminishing results curve: most actions that spectacularly reduced accidents in the past (e.g., Innovation in Personal Protection equipment, adapting international standards and legislation, and innovative safety programs; Figure 1) now hardly get us the exponential gains we saw years back, regardless of the investment we put on them. Furthermore, the improvements in safety of the last 3 decades have been creating new sets of issues that start to show their face such as: By reducing accidents we can create feelings of invulnerability as we lose view of the consequences. With innovative protection equipment we increase Risk Homeostasis, meaning that people behave in a more dangerous way in order to maintain a constant level of risk in their lives (Getting closer to fire after getting better fire-proof garments for example). Too much Legislation can create a feeling of disengagement from personal responsibility. And despite improvements, we haven’t really solved the production vs safety confrontation, it is now stigmatized and less visible, yet it tends to reappear in moments of weakness.

Jan 1, 2019