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We describe a new method of characterising the effect of dissolved materials on the rate of coalescence of bubbles in aqueous media. Single bubbles were allowed to rise to meet the surface of an aqueous solution, and the time of persistence between arrival and bursting of bubble was measured as a function of solute concentration. A laser beam was placed just above the surface of the liquid, with a detector in the light path, so that any disturbance at the surface could be seen as a break in the beam. The arrival of a bubble at the surface could be detected from the behaviour of the trace on an oscilloscope, and when the bubble broke, another significant change in the signal could easily be seen. The time between disruptions was reported as the persistence time. The effect of a homologous series of n-alcohols (C1 to C8) on the persistence time was measured, in aqueous solution. It was found that with increasing concentration of a particular solute, the persistence time increased up to a point, and then declined. However the magnitude of the persistence time was found to increase with increasing numbers of carbon atoms in the molecule. Bubbles of 1, 2 and 3 mm diameter were used. Persistence time increased with increasing bubble diameter, the maximum values observed being of order 100 secs. For a given solute, the persistence (drainage) time increased with increasing bubble diameter. The concentration Cmax at which the maximum persistence time was observed, was found to be independent of the bubble size. It decreased uniformly as the carbon number increased, and was well correlated by the function y1/2 (dy /dc) -2 I dc)-2 . There was no apparent correlation with the surface excess at maximum persistence time.

Jan 1, 2006

By Ernest Baafi

A simulation model RoadSIM using the ARENA modelling system has been developed to evaluate roadway development options for a given development panel configuration. The RoadSIM simulation system has provisions for variability/randomness in operations including cutting and loading at the face, tramming and discharge of coal to the boot end and availability of equipment. The modelling system provides a means for assessing the operational limitations of roadway development practices at a particular coalmine. It is a ?what if? tool that allows a range of equipment, configurations and operating practices to be assessed in terms of achievable advance rates and equipment utilisation. Output from the system is in the form of a dynamic visualisation as well as summary reports and detailed logs of operations over time.

Oct 1, 2009

By Dalton. J. L., H. P. Dibbs

An account is given of investigations into the application of two neutron methods to the on-line analysis of slurries. One deals with the application of the neutron moisture gauge principle to the determination of the water content of iron oxide slurries, and the other with the application of gamma radiation from thermal-neutron-capture to the determination of the composition of aqueous slurries of iron oxide, copper oxide, zinc oxide and sulphur. Linear relationships were found between the composition of the slurry and the neutron count-rate in the first study, and between the slurry composition and the prompt-gamma-ray count-rate in the second study. A mathematical relationship has also been developed which relates changes in the prompt-gamma-ray counts from hydrogen to changes in slurry composition.

Jan 1, 1973

By W. P. Campbell

Introduction OWING to the necessity of curtailing the length of this paper, nothing like an exhaustive treatment of the subject will be attempted. Instead, merely a few aspects will be considered, viz., water trouble in wells, sampling of waters, analysis, methods of reporting analysis, and the comparison of a few typical waters. The waters discussed will not be confined to those occurring in areas where oil or gas has already been found, but will include samples from areas in which drilling is being carried on in the hope that oil or gas may be found, i.e., from unproved fields. The Water Problem The problem of dealing with water encountered in oil and gas producing areas has engaged the attention of petroleum engineers from the early days of the industry. Water was not always considered a menace to oil sands; indeed, a certain amount of it was considered beneficial in some areas, but if such exist today they are very exceptional. In some fields, the problem is more acute than in others, and at times has baffled all attempts to solve it satisfactorily. Wells have been brought-in with promise of good production, but after a brief period have 'gone to water'. Whether ?it has always been a case of poor engineering in the form of unsuccessful water shut-off of 'top' or 'bottom' water, or because 'edge' water was present and water and oil were in such close contact it was impossible to remove the one without the other, is hard to say.

Jan 1, 1929

By Daniel D. M. Adams

Over the last 100 years industry in general has been trying to advance the ability to maintain systems through management processes. Mining has looked to utilize onboard data systems in our mobile mining fleets to compliment these processes. Combining the two concepts build the concept that Rio Tinto refers to as asset health. These programs can generate a cost shift between $20,000 and $100,000 per piece of equipment annually. Even with the documented savings many operations struggle to justify the systems, why?

May 1, 2011

By Camilo I. Morales

At present, many open pit mines are designed to operate and feed a processing plant with ore characteristics that were defined in the design of the mining business, which are not necessarily the same as those found during the operation. This is the case of Spence Mine, whose design was conceived considering the extraction of primary iron sulphides, however, with the extraction of such minerals, it was necessary to mine and process minerals with secondary enrichment. Then it is necessary to work with a greater selectivity degree in the operation, however the capacities of the mine and operational resources were not designed for this. Thus, the changes in the general conditions of the operation should be considered as a series of geometallurgical restrictions to achieve production schedules. The above facts impacts directly in the short-term planning, whose task is to achieve the goals proposed in productive long-term planning because the company does not have the tools necessary to plan with the degree of selectivity required, so it should be done by hand, discretizating and scheduling the production polygons. Naturally, this manual process in the short term planning deviate sharply from the areas in operation, opening new fronts and benches that result in a significant increase in costs and a loss of the value of the mineral resource to miss the exploitation sequence. The research presented in this paper is related to the development of a mathematical programming model to support the short-term planning, so as to integrate the challenge of selective mining with geometallurgy restrictions, to provide the planner a guide to construction of the polygon of exploitation, guiding the fines production to achieve the goals of the proposed production plan.

Oct 1, 2009

By T. R. Kostecki

"Instrumented rock bolts are effective tools for assessing the reinforcement and condition of immediate roofs; however, instrumentation can have relatively high costs, which can be justified by high reliability and repeatable and representative data measurements. The instrument’s durability and operational life are of great importance, along with accuracy, applicability, and usefulness. This paper develops reliability models for three instrumentation technologies used in slotted rebar, drawing data from studies at five underground coal mines. Three case studies demonstrate instrument applicability and usefulness. Finally, two types of instrumented rock bolts are used to determine the direction of bend and maximum bending strain. RÉSUMÉ Les boulons d’ancrage instrumentés sont des outils performants qui permettent d’évaluer la consolidation et la condition des toits immédiats. L’instrumentation peut cependant se révéler très onéreuse, des coûts qui se justifient par sa fiabilité élevée ainsi que par des mesures de données reproductibles et représentatives. La durabilité de l’instrument et sa durée de vie opérationnelle sont très importantes, de même que son exactitude, son applicabilité et son utilité. En s’appuyant sur des données issues d’études menées dans cinq mines de charbon souterraines, cet article développe des modèles de fiabilité pour trois technologies d’instrumentation utilisées pour des barres d’armature nervurées. Trois études de cas démontrent l’applicabilité de l’instrument et son utilité. Enfin, deux types de boulons d’ancrage instrumentés sont utilisés pour déterminer la direction de la flexion et la contrainte de flexion maximale.INTRODUCTION Using instrumented rock bolts to monitor strain changes in a rock bolt array allows engineers to understand the per-formance and effectiveness of the rock reinforcement system and the response of the rock mass to such support; however, instrumentation remains a niche solution for solving complex ground-control problems—particularly for underground coal mines, which is where they are needed most. From 2000 to 2016, fall-of-ground fatalities still accounted for an average of approximately 30% of the total annual underground coal mine fatalities in the United States alone (United States Department of Labor, 2018). These tools would also be useful for deep hard-rock mining conditions. The main reasons for the lack of widespread use are not only cost but also accuracy, applicability, implementation procedures, intrinsic permissibility, and reliability (Peng, 2015). As a result, measurements of coal mine roof behaviour using instrumented rock bolts are quite scarce, not widely published, or inadequately presented to provide a seamless understanding of a roof’s response to support."

Jan 1, 2018

By A. C. T. Bigg

"The mineral potential of the Nanisivik area was discovered as far back as 1910 when a prospector of the Geological Survey of Canada, on an expedition under Captain J. G.Bernier, recorded a deposit of pyrite with minor sphalerite and galena. An outcrop of the present orebody was discovered by Texas Gulf Company in 1957. Subsequent drilling outlined the orebody consisting of 6,000,000 tonnes of ore containing 13 % Zinc and 1.5 % Lead. The orebody appears to have been formed by the filling of a limestone cavern with sulphides. The sulphide minerals consist of pyrite, sphalerite and galena. The limestone bedrock is mostly dolomite with some calcite and magnesite. A cutoff grade of about 6% Zinc has been calculated.In 1972 Mineral Resources International Limited took an option on the property. Upon completion of the feasibility study by Watts, Griffiths and McOuat, the then new independent project management group of Strathcona Mineral Services Ltd. were engaged to develop the project through the financing, construction and operating phases. Strathcona Mineral Services still manage the project from their head office in Toronto and through the Mine Manager and Department Superintendents at the Mine site. The interest for the project is presently split five ways: Mineral Resources International Ltd. 53.5 %, Government of Canada 18 %, Metallgesellschaft A.G. of Germany 11.25 %, Billiton B. V. of Holland 11.25 % and Texas Gulf Co. 6 %."

Jan 1, 1980

By D. Kidby, A. Briggs

"Vitrokele ™ is a synthetic adsorbent, using chelating groups on large polystyrene beads, developed in Canada over 7 years ago, and first commercialised in 1985 to recover noxious metals from plating wastes.Pilot plant trials have been performed in Australia and Canada to demonstrate the recovery of cyanide and removal of metal cyanide complexes from gold plant effluent using Vitrokele1 M 912. The pilot plants comprise a simple adsorption train (similar to a CIP circuit) followed by complete elution facilities, so that loaded Vitrokele™ can be stripped and returned to the adsorption circuit.An account of these campaigns is provided, showing the reduction of total CN levels from over 200 ppm to less than 0.5 ppm and Cu levels from approximately 100 ppm to less than 0.3 ppm in treated tailings.Comparisons between pilot plant results and laboratory test data are given and probable future work on the process and its application to the gold mining industry is discussed.INTRODUCTIONThrough millions of years of evolution, life forms have developed specialised molecules with exceptionally high affinity and selectivity for various metals such as iron, cobalt, zinc and copper.In the early 80's professors at the Faculty of Medicine of McGill University engaged in research on the extremely efficient ways that living cells captured trace metals essential for life.As research progressed, it became evident that the special molecules used by biological systems to capture metals could be synthesized to capture selected metals with similar efficiency from water or other solutions.The technology was first commercialised in 1985 to recover noxious metals from plating wastes with compositions applying the special molecules (chelating groups) on vitreous particles (hence Vitrokele™). To date approximately three commercial Vitrokele™ plants have been installed for treating plating waters in Ontario and Quebec."

Jan 1, 1992

By D. B. Dreisinger, D. G. Dixon, G. Nazari

"The kinetics of chalcopyrite leaching in acidic ferric/ferrous sulfate media under atmospheric conditions in the presence of pyrite has been investigated. It has been found that pyrite samples from different sources affect the rate of chalcopyrite leaching differently. A strong correlation between the amount of silver associated with the pyrite and its effectiveness has been noted. In this study, improvement of the catalytic properties of pyrite such that all pyrite samples accelerate the rate of copper extraction regardless of their sources is demonstrated, and a detailed discussion of the mechanisms involved in the process of chalcopyrite leaching in the presence of silverenhanced pyrite is presented. INTRODUCTIONIt is well known that chalcopyrite resists leaching in sulfate media. It has been proved that pyrite facilitates the leaching of chalcopyrite (Berry et al., 1978; Dixon et al., 2008; Mehta and Murr, 1983; Muñoz et al., 2008; Nowak et al., 1984, Tshilombo, 2004). Considering the catalytic effects of pyrite on accelerating the kinetics of chalcopyrite leaching, Dixon and Tshilombo (2005) have developed a new process, known as Galvanox™, which has several advantages over other hydrometallurgical processes. Galvanox™ runs under atmospheric conditions, so it requires only low-cost leaching tanks. The sulfur yield at this temperature is high (>95%) which leads to low oxygen consumption and low sulfuric acid generation. The operating temperature is below the melting point of sulfur which eliminates the use of surfactants. This process also does not require fine grinding. Reaction 1 shows the overall leaching reaction in the Galvanox™ process.CuFeS2 + O2 + 2 H2SO4 = CuSO4 + FeSO4 + 2 S0 + 2 H2O (1)Complete copper recovery from the Galvanox™ process can be achieved at a considerably higher rate than other atmospheric ferric sulfate leaching processes (Dixon et al., 2008). Recycling pyrite and recovering copper from tailings with the Galvanox™ process have also been evaluated in continuous pilot leaching campaigns (Dixon et al., 2007)."

Jan 1, 2012

By J. W. Gregg, P. M. Dranchuk, D. L. Flock

"From preliminary investigations it has been observed that although evaporation losses may be estimated by comparing single values of certain physical properties of crude oils and their evaporation residues, such techniques possess little accuracy unless both the evaporation process and the variation of the property as a function of the process are completely known. The accuracy of estimation may be increased somewhat through the comparison of property mid-per-cent curves. Further increases in accuracy are possible if bottoms yield •curves rather than mid-percent curves are used. The use of both the mid-percent and bottoms yield curves however involves a prohibitive amount of effort in most cases. Examinations of distillation bottoms from Hempel type distillations carried to end points just short of the cracking point have indicated that these bottoms are not appreciably affected by the evaporation process. It was further observed that bottoms of identical API gravity, obtained from a crude oil and its evaporation residues behave as if they were pure components which were unaffected by evaporation. Based on these observations Hempel distillation bottoms of equal API gravity were obtained for a crude oil and its various evaporation residues from API gravity bottoms yield curves. The volume percent of these bottoms in the crude oil and its residues were used to calculate the evaporation losses suffered by the crude in order to yield the various residues. The results indicate that, although further refinements in technique are required, it is possible to calculate evaporation losses with an accept-able degree of accuracy through the use of this method."

Jan 1, 1960

By V. A. Ettel

Current practices in electrolytic winning and refining of copper , nickel and zinc are reviewed from the point of view of their respective energy requirements. The electrical energy requirements of these processes are broken down in to the individual components, which belong to two basic categories: (a) thermodynamic energy requirements (G of the desired reaction) : (b) energy losses (anode and cathode polarizations, ohmic drops in the electrolyte and in the cell hardware, energy losses due to unwanted side reactions and electrical shorts). The individual energy components are separately examined for each electrolytic process and the potential for energy saving in these processes is discussed. It is shown that many potential energy-saving measures are uneconomical at the present time, as they increase over-all operating costs. The discussion is focused on those approaches which hold most promise for the future.

Jan 1, 1977

By Mario E. Rossi

The full economic evaluation of a mining project requires a block model that provides an estimate of the tons and grades of available resources. The model must be representative of the mineralization to be found at the time of mining for specified extraction periods and within acceptable error margins. In an operating mine, there may be a reasonable understanding and estimates of actual dilution and ore loss. This paper discusses the issue from the perspective of a project at a feasibility or preproduction level of development. Three types of dilution are discussed. Internal dilution (or change of support) is function of the spatial distribution of the mineralization and its relation to the operation?s selectivity. Geologic contact dilution is the unavoidable mixture at contacts or boundaries of material with different geologic characteristics, grades, or metallurgical performance. Operational planned and unplanned dilution should also be considered, sometimes incorporated by factoring the resource model, but more accurately by mimicking the grade control process. The resource estimation process always carries uncertainty, which is sometimes significant, and usually caused by several factors. These include quantity and quality of drill hole information; quantity and quality of geologic data; grade estimation methodology; dilution and mining recovery factors applied; etc. A key decision is to whether estimate as accurately as possible the in-situ geologic resource or to estimate the tons and grade of the material to be fed to the processing plant. The geologic modeling and grade estimation methods used are conditioned by this decision.

May 1, 2009

By Norman R. Paterson

"Under certain conditions useful gravity information of a reconnaissance nature can be obtained with-out measuring elevations by spirit level surveys on the ground. Gravity surveys can become part of a practical exploration program where high cost and slow progress previously hindered their utility. The advantages of the new elevation procedures are realized mainly in remote areas, in areas where ground transportation is slow and difficult and on surveys where the station spacing is large in comparison with the distance of the average optimum level shot. To utilize the advantages, transportation by helicopter or light plane is usually necessary. Methods of obtaining elevation control without leveling include: barometric altimeter survey; photogram-metric -APR spot determinations; methods involving the measurement of gravity gradients. The accuracies of these methods have been tested and compared with the normal accuracy of level surveys. It is felt that each method has its place in reconnaissance gravity work, particularly in the open areas of Northern Canada."

Jan 1, 1960

By Cecilia Arrue, Dominic Fragomeni, N. O. Lotter

"A statistically designed benchmark mill survey was carried out in July 2005 at the Kidd Creek Concentrator, D Division circuit, which processes Ni/Cu ore from the Montcalm deposit. A structured statistical survey approach was followed, together with defined quality controls, which would assign a 95 percent level of confidence in the result.A set of six surveys were completed over a limited time; the corresponding stream samples of the surveys found acceptable were combined to obtain high confidence composite samples. The head grade of each survey is compared to two distributions to test its acceptability; surveys that fail to conform to these trials are rejected. The accepted set of surveys, which is a robust representation of the process, is prepared into a composite for QEM-SEM analysis and mass balance purposes.Where the above practice is a standard procedure in Falconbridge for QEM*SEM purposes, in this case each individual two-hour survey unit was measured and analysed for a mass and value balance. It is shown that none of the individual mass and value balances close as well as the composite set of accepted two-hour survey units. This founding is in keeping with the averaging properties of the Central Limit Theorem.INTRODUCTIONMontcalm OperationsNi/Cu bearing ore from the Montcalm deposit is being processed at the Falconbridge, Kidd Creek Concentrator in a modified D Division circuit. The circuit was commissioned in the fall of 2004. Ore is crushed at the minesite to –19 mm and trucked to Kidd for delivey into the 4 parallel fine ore bins.Ore is milled in a rod mill followed by cyclones and 2 parallel ball mills. The grinding circuit treats Montcalm ore at an average feed rate of 100 wet tonnes/hour (750,000 tonnes/annum) and produces a flotation feed particle size of 83% -53 um. A simple flowsheet including bulk Cu/Ni roughing and 2 bulk cleaning stages followed by Cu/Ni separation in 2 stages is practiced. Soda ash is used as a pH modifier in bulk flotation. SIBX is the collector. Lime and Dextrin are added into Cu/Ni separation for the depression of pentlandite."

Jan 1, 2007

By H. U. Ross

"INTRODUCTION Extensive studies have been carried on pure gold to determine the various factors that affect its dissolution in alkaline cyanide solutions. With the extension of milling to refractory ores more intensive investigations on the effect of impurities in the ore on the dissolution kinetics are needed. The present work describes experiments carried on refractory flotation tailings with the object to determine how the recovery of gold could be increased. The effect of arsenic and antimony in the ore and the excessive use of lime are discussed. Control of cyanide losses is also dealt with.MECHANISM OF THE GOLD DISSOLUTION REACTION In aqueous cyanide solutions, gold is believed to be dissolved by one of the following reactions:4Au + 8NaCN + O2 + 2H20 = 4NaAu (CN)2 + 4NaOH (1)2Au + 4NaCN + 2 + 2H20 = 2NaAu (CN)2 + 2NaOH + H202 (2)2Au + 4NaCN + H202 = 2NaAu (CN)2 + 2NaOH (3) The first of these, known as the Elsner Equation is supported by )4 3,2,1(several authors while others(5,6) support reactions 2 and 3 known as the Bodlander Equations. According to Habashi(7), the overall reaction for the dissolution process is as shown in equation 2. Most of the workers agree that hydrogen peroxide is produced in the course of the reaction."

Jan 1, 1973

By R. W. Lawrence

"In the past year, BioteQ Environmental Technologies Inc. have initiated design and construction of new plants to add to an existing list of plants that utilize the BioSulphide® and ChemSulphide™ process technologies for metal recovery and water treatment. In these plants, low cost biogenic sulfide or, in some cases, chemical sulfide reagent is used to selectively remove metals from contaminated water. The process produces high grade, marketable, metal sulfide products even from low grade feed solutions. The revenues generated from the sale of products can allow for water treatment at a profit in some cases, offset treatment costs in others, and generally reduce sludge disposal and management costs. The effluents produced from the process can meet stringent environmental standards. Current plants in operation and under construction range in sulphide demand from 50 kg/day to 3.7 tonnes/day, with the feasibility of larger plants with sulfide demands ranging from 6 to 43 tonnes/day under review.Biogenic sulfide reagent can also be considered for other applications in hydrometallurgy and mineral processing. Uses under consideration by a number of mining companies include: (1) replacement of sodium hydrosulphide in the SART process for cyanide regeneration and copper recovery in the processing of gold-copper ores, and (2) replacement of sodium hydrosulphide for use in the separation of copper and molybdenum in flotation. Biogenic sulphide, produced on demand at site, offers significant cost savings and provides the additional benefit of improved safety due to the elimination of the transportation, handling and storage required for chemical sulphide reagents.This paper reviews the applications of the BioSulphide® and ChemSulphide™ technologies for water treatment and metal recovery, and introduces projects where biogenic sulfide can be applied in hydrometallurgy and mineral processing."

Jan 1, 2007

By W. Tse, D. Wong

Dense medium separation (DMS) is one of several preconcentration methods used for early waste rejection from run of mine ores at relatively coarse particle sizes prior to additional milling and beneficiation. DMS has been used extensively in the coal, diamond and iron ore industries but lab scale and pilot test work has demonstrated successful separation and upgrading of other minerals such as lead, zinc, copper and lithium based ores using DMS. This paper reviews historical dense media systems, results from the pilot scale Condor DMS system as well as associated laboratory heavy liquid separation (HLS) test work.

Jan 1, 2014

By Bob Robinson

In 1990, the European Space Agency (ESA) initiated a technology transfer program to stimulate the wider use of technology developed by the European and Canadian space communities. This paper focuses on the method of technology transfer from the space industry to terrestrial industries, with a focus on the mining resource sector within a program called the Harsh Environments Initiative (HEI) created in 1997. Other resource sector applications include forestry and oil & gas. C-CORE in partnership with the Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO) supported by ESA, Canadian Space Agency (CSA) and European R&D organizations conduct projects to promote and demonstrate the transfer of innovative technologies from space to non-space industries. Space programs have and continue to develop new knowledge for extra-terrestrial application, e.g., satellite earth observation, manned missions and unmanned planetary exploration. Many of which hold the potential for application on land and ocean. Currently, space technologies of interest to the mine sector range from robotics and image analysis to sensors, software and advanced materials. The HEI works to identify and apply these types of technologies in the areas of automated/tele-controlled mine operations and mine monitoring.

May 1, 2001

By Robb. V. M., F. Walraven, L. J. Robb

"Abstract -The old Albert Silver Mine is a polymetallic deposit comprising concentrations of Cu­ Pb-Zn-Ag-U-F within a set of sub-parallel quartz-hematite veins which occur within the fine-grained apical phase of the 2050 Ma old A-type Bushveld granites. Mineralization occurs as an early pyrite­ chalcopyrite-arsenopyrite-galena-sphalerite-(argentiferous) tetrahedrite paragenesis followed by a later, more oxidized assemblage comprising chlorite-hematite-fluorite-pitchblende. Accumulation of metals appears to have taken place at the interface between a coarse-grained porphyritic granite and an overlying fine-grained phase: veins occur in the latter and represent leakage of magmatic fluids from the differentiated, water-saturated, subjacent granite.Mineralization processes in the Bushveld granites are believed to be related to long-lived circulation of dominantly magmatic fluids stimulated by the high heat productive capacity of the host rocks. Endo- and exogranitic tin-tungsten and base metal mineralization formed during an evolving hydrothermal system that lasted for several hundred million years, forming innumerable small- to medium­ scale polymetallic deposits. At the Albert Silver Mine, unroofing of the cover sequences at circa 1600 Mato 1700 Ma resulted in the incursion of lower-temperature, high-f02 meteoric fluids which remobilized the earlier sulfides and introduced the paragenetically late U-F mineralization ."

Jan 1, 1994