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By E. G. Joe

"This paper summarizes the main conclusions derived from twenty-two technical presentations made at the 1973 meeting of the Canadian Mineral Processors. Results of two surveys with response from over seventy mines were reported on Canadian milling practice for water re-use and on elimination of cyanide from mill effluents. Water and solution recycle in Canadian mills were detailed for copper, copper-zinc, lead-zinc-copper, nickel-copper, iron and gold mines. Cyanide elimination from mill effluents was reported under current practice and under requirements for further treatment by various other processes. Three recent process equipment entries into Canadian mills have been the on-stream particle analyzer, the new gravity concentration tables for recovery of fine tin and other heavy minerals, and solution-jet slurry equipment for reclaiming ground ore from storage. The principles of operation of this equipment were described along with the practical limitations that were found in their application to mineral processing. Capital costs and milling cost reductions were shown in some operations. Computer control of flotation mill processing was a major item on the program. Four major mining companies outlined their mill process control strategy, computer programs and on-stream analysis equipment. Some capital costs and personnel changes were presented, together with gains in concentrate grade and mill recovery. Recent development work has shown the effect of the type of grinding and of aeration on the recovery of sulphide minerals in flotation. One mining company reported a significant depressing effect on copper sulphide flotation while floating ore ground with mild-steel balls; also, pyrite appeared to be activated in the subsequent zinc flotation step. One company with extensive experience in the application of aeration to copper sulphide flotation showed significant improvement to copper recovery by pre-aeration. Both the effects of grinding and aeration were subject to the constraints of the chemical condition of the ore pulp. The metallurgy of silver recovery by combination grinding - gravity treatment and of gold recovery from a complex gold-sulphide ore were reviewed in two papers on precious metals. The latter paper further described the recovery of gold from the Cottrell collectors and the final disposal of arsenic from the dust collectors."

Jan 1, 1973

By D. Hu, L. Matzar, J. Hampton, M. Gutierrez

Nanodarcy permeability is common in many oil- and gas-bearing formations requiring unconventional stimulation technologies, such as hydraulic fracturing (HF), which can connect the isolated hydrocarbon-rich pores with a wellbore through induced fracture networks. Even though a dense induced fracture network is capable of accessing economic amounts of hydrocarbons, much of the rock between and very close to the fracture network is still un-accessed and contains extremely low permeability. Inducing fracture networks into brittle rock can create large amounts of micro failures in surrounding regions that are not connected to the wellbore, as can be seen in Fig. 1(a) from the very wide acoustic emissions (AEs) cloud associated with a narrow fracture generation. It is possible in certain types of rock to increase the effective matrix permeability in localized regions based on the damage associated with the surrounding hydraulic fractures and subsequent high stress concentrations along localized pre-existing potential failure zones. To study this problem, laboratory HF tests were performed at true-triaxial stress state in brittle crystalline rock while monitoring AEs. The AE associated with HF was analyzed for source parameters using the moment tensor inversion method called Simplified Green’s Functions for Moment Tensor Analysis (SiGMA). Using the moment tensor for each individual AE event, the mode of failure was determined. Crack slip directions and crack face normal directions were also found, along with the relative volume of individual micro failures as well as a damage parameter. The associated source parameters were used to classify differing regions of damage in the sample induced from HF and correlate these regions of differing damage to the effective drainage region. Shown in Fig. 1(b) is a near-wellbore (NWB) region that contained three times larger average relative volumetric deformation of individual tensile AE events than the average tensile AE event volume from the entire sample. Because of the large difference in micro fracture volumetric deformation for the NWB region compared to the entire sample, predictions of HF induced damage must be included in reservoir drainage predictions.

Jan 1, 2015

By G. Deschênes

"In 2013, as the prices of precious metals dropped, investors moved their positions to equity markets for higher returns. As a result, the price of gold dropped further to below US$1200 per ounce, prompting additional substantial outflows from gold investments. In response to lagging gold prices, major gold producers initiated large asset write-downs and cost-cutting programmes. In 2015, this trend continues and gold mining stocks are close to lows not seen since the global financial crisis (GFC) of 2008. In the current economic climate many projects have marginal economics, and the number of projects that have competitive development and production costs is declining. A competitive edge is particularly important with the decreasing grades of orebodies, increasing complexity of the mineralogy, and increasingly demanding environmental constraints. In addition, higher cost producers seek to optimize their process t o reduce operating costs.This paper presents some highlights of three case studies on optimization of gold leaching strategies that improved the economics of brownfield projects. Processing of sulphide-bearing ores was optimized by using the synergy between cyanide, lead nitrate, and oxygen. The outcomes were significant reduction of retention times while maintaining or increasing gold extraction and reducing cyanide addition and effluent treatment costs. A stirred tank reactor experimental programme led to direct implementation of reliable leaching strategies from laboratory scale to production. This approach resulted in savings of $2.2 million to $15.2 million on the three brownfield projects discussed in this paper."

Jan 1, 2016

By D. R. Rice

"The Smoky Valley Common Operation is managed and 50 percent owned by Echo Bay Mine' s Round Mountain Gold Corporation. The other partners with 25 percent each are Homestake Mining Company and Case Pomeroy. The operation in central Nevada includes an open pit, 3-stage open-circuit crushing train and heap leaching on asphalt pads. Presently, about 18,000 tons per day of 0.039 troy ounce gold per ton are transferred to the leach pads, and a similar tonnage of leach residue is transferred to a waste dump. One million tons of ore are being leached at any one time.Gold and silver cyanide are adsorbed from pregnant leach solution on activated coconut shell carbon granules. Pressure stripping desorbs values from loaded carbon to electrowinning solution.Three electrowinning cells are operated in parallel. Each contains six cathodes. Each cathode includes about 40 troy ounces (2.7 pounds) of Number 2 medium coarse steel wool. The wetted area of each cathode is about 24 by 30 inches. Solution flow is 2 to 3 gallons per minute per electrowinning cell. Average current flow is 25 amperes per cathode. The voltage is controlled in the range of 3 to 4 volts to maintain desired amperage.Twice a week two cathodes are pulled from each cell and drained. Each cathode is split into four portions. These are put in a steel pan coated with WD-40 and dried overnight.Each dried cathode portion is put into a paper sack. Each group of four sacks corresponding to a cathode is weighed together. The typical weight ratio of loaded cathode wool to new cathodes is 9 or 10 to 1. To each sack is added 35 troy ounces of silica, 45 troy ounces of anhydrous borax, 35 troy ounces of nitre, and 5 troy ounces of fluorspar. The sacks are taped shut."

Jan 1, 1986

In April, 1961, a large pillar was removed by blasthole mining methods at Inco's Murray mine. More than half a million pounds of explosives were used to break 2,120,000 tons of ore in a single underground blast. The 5, 10 2-inch boreholes, involving 435,815 feet of drilling, were loaded over a three-week period, using conventional explosives and short-period electric caps. From this blast, more than half a million tons of ore have been removed to date (April, 1962) through slusher trenches situated in the footwall of the ore body. T HE Ontario Division of The International Nickel Company of Canada, Limited, operates six underground mines and two open pits in the Sudbury district in the north-central part of the Province. This paper describes the removal of a large pillar at the Murray mine (Figure 1), where 2,120,000 tons of ore were broken in a single underground blast by the blasthole mining method. This is the largest underground blast achieved to date (April, 1962) at Inco mines.

Jan 1, 1963

By G. M. Behrend

"The mining and processing of mineral ores is a very old industry which is steeped in tradition. Rising demand for metals has recently forced the exploitation of lower-grade orebodies which require extensive beneficiation. The high capital expenditures involved, together with market pressures for high-quality concentrates and pellets, have forced the development of new process technologies which are heavily dependent on automatic process control. Development of suitable instrumentation has been rapid and it is being applied to mining processes today with a high degree of sophistication. The drive for higher efficiency and profitability goes on and has reached a level at which modern digital computers appear to be the only answer. However, the efficient application of a digital process computer is extremely complicated and is therefore approached by the mining industry with considerable hesitation.Some of the benefits promised by the digital computer can be obtained today by other means, which are more manageable and can provide immediate payoff. The result would be a building-block system which would utilize the digital process computer as its final component, to perform true plant optimization, free from routine chores."

Jan 1, 1971

By L. M. Wang, G. P. Jiang, Y. Jiang, Liao. W. S.

ABSTRACT The authors measured porosities and permeabilities for cores from a low-permeability sandstone uranium deposit in Inner Mongolia. Features studied included fine pore structure, mineral composition, cation exchange capacity, granule appearance, and cementing features. In general, grading of the grains was relatively poor, which decreased the radii of the pore channels. The pore throat distribution was significantly heterogeneous. Pore channels ranged from small to large, but the lack of large pore channels led to low permeability. Cementation by calcite and clays, including montmorillonite, chlorite, and kaolinite, resulted in pore channel narrowing, further decreasing the permeability of the formation.

Jan 1, 2014

By Lanny Pasternak

"This article is directed at plant production, engineering and maintenance personnel. Seldom does any industrial operation take the time to study the costs involved in the generation of what is probably their most expensive plant utility energy source.IntroductionIn the typical industrial plant in Canada, a 200 hp, 900 cfm, air compressor costs about $60,000* per year to operate (Fig. 1). In 1989 when BC Hydro embarked on their industrial energy management program Airflow Energy Ltd. were asked to spearhead the “Efficiency Compressed Air” portion of that program with a mandate to perform onsite overview surveys and physical hands-on testing of some 300 selected industrial plants throughout British Columbia for compressor efficiencies and wasteful air leaks (Fig. 2). The program duration lasted until 1995, during which time a tremendous amount of data were amassed relating to equipment types, clients’ operating habits, end-use applications and operating costs.During the past six years, Airflow Energy also performed somewhat similar surveys but on a smaller scale in Alberta, Ontario, the United States and the Republic of China. It was no surprise to find some inherent equipment concerns related to efficiency as well as neglected energy wasteful air leaks, so British Columbia was not alone and the problems appear somewhat universal."

Jan 1, 1996

By G. F. Flaherty

THE property of Tashota Goldfields, Limited, in the Lake Nipigon area, Ontario, is located about 4 miles west of Onaman lake and 16 miles by winter road south-southeast of Tashota station on the transcontinental line of the Canadian National railways. The mine, formerly developed to a limited extent under the name of Tashota Gold mine, has, since late in 1933, been under the management of Minefinders Limited, who, in 1935, brought it into production on a 60-ton per day basis. During the winter of 1934-35, the writer was geologist at the property. The geological structure in the immediate vicinity of the mine workings lends itself well to analysis on the basis of the mechanical principles of folding. Since structure is of prime importance in the localization of the ore-shoots and of the host shear-zones at the property, the correlation of all structural details and their mechanical interpretation forms a working hypothesis of structural control for the direction of exploration and development work. It is believed that the structural relations here set forth may be found applicable in part, or at least suggestive, in working out the relations of ore-shoots to structure in the Sturgeon River area to the south, and in the Little Long Lac area to the southeast (Figure 1).

Jan 1, 1936

By Malcolm Scoble

Process Technologies Suitable for Application Underground Design Criteria - coarse particle technologies - compact, robust, flexible - waste products suitable for use as backfill Process technologies identified: - Optical/conductivity sorting - Dense media separation - Coarse-particle flotation Process technologies supported by compact & efficient comminution stages Mineralogical evaluation to select process & estimate Performance Further Work U/G Plant Layout & Excavation Modelling Evaluate scenario at increasing depth Establish properties of waste as backfill Model impact of improved backfill quality Evaluate further case studies Evaluate further Environmental Health and Safety Issues Model impact of system development on inventory of national mineral reserves Conclusions Technologies exist for integrated underground mining and processing systems These technologies to be successfully integrated into underground mining system Positive economic and environmental benefits Technical issues to be resolved at depth System Development path identified

May 1, 2004

By S. S. Burns

"AbstractShovels of 18 cubic yard capacity and larger are described which incorporate advanced technology and techniques providing performance and operation tailored to meet the needs of open-pit mining.To achieve the goal s of increased production at lower cost with consideration of maximum availability, lower energy consumption per ton and low •impact on pit power, Harnischfeger Corporation developed a solid -state drive system (""Electrotorque"" - P&H trademark) and applied unique transmission methods.To date, more than 250,000 hours of experience in different parts of the world under varying operating and environmental conditions has proven that the ""Electrotorque"" shovel is the shovel of the future, today.This paper will discuss the electrical features and touch briefly on some mechanical features.Introduction to ""Electrotorque""THE hoist, crowd, propel and swing machinery of an electric mining shovel are driven by direct-current motors.A D.C. motor is used instead of an A.C. motor because the torque output per ampere input is at a maximum and the fact that it is doubly-fed (armature and field ) provides optimum flexibility in control.The power that is available in the pit is alternating current power. It is therefore necessary to change or convert this A.C. power to D.C. power so that the D.C. motors can be used."

Jan 1, 1977

By W. L. Dam

Grand Junction, Colorado’s legacy with uranium mining and milling serves as a model attracting international interest. Access to water and central location to carnotite ore containing uranium and vanadium resulted in the World War II military creating a site in Grand Junction for developing extraction techniques; subsequently, several commercial mill sites were built in the area. Uranium mills produced ore into the 1970’s as well as tonnes of radioactive waste tailings. Tailings contain radium that emits radon gas. Despite the radiation hazard, sandy tailings were added to concrete and became incorporated into roads, schools, businesses and homes. Clean up of sites containing tailings and mill sites began in the 1970’s involving city, state, and federal officials. The Climax mill site had become an auto junk yard mixed with mill tailings. A new disposal site was built out of town and away from the river in the 1990’s. After Climax mill tailings were removed to the disposal site, the land sat vacant for two decades until citizens and city officials developed a masterplan for the riverfront property. The Las Colonias river park is being built in stages including an amphitheater, gardens, businesses and parks. One of the biggest obstacles to site remediation and reuse was overcoming public outrage, fear, and lack of trust which made funding sources scarce.

Jan 1, 2020

By F. H. Edmunds

LLOYDMINSTER is the centre of a well developed agricultural area, lying on the Alberta-Saskatchewan interprovincial boundary in Township Fifty. The surrounding country is gently undulating, without any notable topographic features, but twenty-two miles to the north the North Saskatchewan river, and thirty miles to the south the Battle river, have cut deep valleys. In the spring of 1934, a wild-cat well (Lloydminster Gas Company's No. 1 well) was successful in striking a large flow of gas at a depth o 1,974 ? feet. The gas was piped into the town, a short distance south, and Lloyd-minster became the first Saskatchewan town to be served with natural gas. Following this discovery, other wells were sunk and, up to the present, thirteen wells have been drilled m what is here designated the Lloydminster area. Ten of these wells are in Saskatchewan and three in Alberta. Seven were successful in obtaining gas, three oil, and three have been unsuccessful. The area tested by this drilling is about eight thousand acres, six thousand of which can be considered as proved gas or oil land. To the south and west of Lloydminster, in the Province of Alberta, there are several areas in which oil and gas have been discovered. The Wainwright field lies nearly fifty miles to the southwest; Battleview, where recently gas has been discovered, is thirty miles west-southwest; and the Ribstone area is about thirty miles south and a little west. At Ribstone, a number of wells were drilled some years ago and there is a small production of oil. The data relating to the wells in the Lloydminster area that are recorded in this paper are taken from the records of the several companies operating in the field. The names of these companies are given on the map and on the type stratigraphic section (Figures 1 and 2). The author wishes to record his appreciation to Mr. R. H. Shaw and Mr. 0. C. Yates, both of Lloyd-minster, for much valuable information; also to Mr. E. Swain, of the Department of Natural Resources, Regina, with whom the writer has visited the field on several occasions, and who, by his enthusiasm and encouragement, has done much to forward the development of the area. The well samples were examined at Ottawa by officers of the Borings Division of the Geological Survey of Canada, who also made the interpretations of the logs. Frequent references will be made to the work of Dr. G. S. Hume, of the Geological Survey, and the writer would like to pay tribute here to his work.

Jan 1, 1940

By F. Habashi

Lead is an ancient metal, has been produced to-date from its ores exclusively by pyrometallurgical route. The process suffers from high operating cost and excessive pollution problems. Extensive research has been going on since the beginning of the twentieth century to find a non-polluting process for its production and a solution for its complex refining scheme. It has been assumed correctly that the hydrometallurgical route should be the most promising. Pilot plants have been constructed and operated for a reasonable periods, but no process has proved to be satisfactory. As a result, a number of smelters and refineries have been shut down. The present review analyses the situation and suggests that the best route to treat lead sulfide concentrates is by leaching with fluoroboric acid, HBF4, containing ferric fluoroborate, Fe(BF4)3, and electrolyzing the solution in a diaphragm cell - - a process recently invented by Italian metallurgists. In this process, any silver present in the concentrate remains in the residue together with elemental sulfur and can be recovered by known methods.

Jan 1, 2008

By G. Danko, C. Lu

"High temperature and humidity at the working negatively affect safety and health in deep and hot underground mines. It is necessary to predict during design the dynamic changes in temperature with heat and moisture emitted into the mine ventilation-thermal-humidity (VTH) system from various sources such as auto-compression, wall of strata, mining equipment and workers. Currently available mine ventilation and climate models are either furnished with a simplified, step-change-type (SCT) model for thermal solver (such as in Climsim, VnetPC, Minevent, MFire, etc), or with more advanced models to account for the “thermal history effect” (also known as thermal flywheel effect), such as in Ventsim and MULTIFLUX. The goal is to quantify the modelling error caused by the lack of variable thermal history component in the SCT model. Two models are compared: one with and one without the thermal history component in long, single airway examples with long-term climate simulations for 20 years assuming an input air temperature with daily variation. The examples illustrate the magnitude and the time-lag phase of the variation of the modelling errors with space, time and model conditions. Large errors are shown in the order of +14°C and –7°C errors, persistent for long time periods, up to 20 days in one example.INTRODUCTIONIt is important to predict the heat and humidity distributions during the design of hot and humid underground mines for the safety and health of the workers. The feasibility of extracting a rich deposit in great depth may depend on the extent of ventilation and mine climatization for maintaining an acceptable working environment. The cost of ventilation and cooling may be substantial, up to 40–50% of the total energy cost of mining (Clausen, 2017). The accuracy of model solution is important in view of the low profit margin in mine feasibility for deep and hot mines. Safety and health of the miners, the primary concerns, are therefore inherently connected to finding ever better solutions in simulation methods and ventilation control techniques."

Jan 1, 2019

By T. G. Joseph, E. Lampard

ABSTRACT: Surface mining operations must manage variability from within their operations as well as variability imposed upon them by external forces. A framework to manage both internal and external variability through the continuous review and adjustment of a mine plan during active mining lifetime operation is introduced, to minimize lost production and maintain operational safety. The observational approach of “observe, evaluate, interpret, predict, and adapt” is employed as the backbone of this approach. Although written with a surface mining operation in mind, the framework outlined in this paper would be equally applicable to any mining or processing operation.

Jan 1, 2011

By T. T. Wang, T. H. Huang, S. S. Zhan

"Fractures with diverse features dominate the hydraulic behavior of fractured rocks and are one of the major subjects for hydrogeological characterization of a site. This study investigates curve patterns obtained by packed tests, and as well the influence of fracture features based on 59 sets of in situ packer tests with different fracture combinations and fracture features. The result shows that, in the example of Heshe site, neat and tidy fractures usually provide stable channel for water flow during testing, and the hydraulic properties of fractures infilled with breccia and mud may change during testing because of leaching and/or washed out of infilling breccia and mud. Different combinations of fractures with diverse features in packed test sections lead to different curve patterns for in situ hydrogeological tests. For groundwater flowing predominately through neat and tidy fractures, the pressure-discharge curve of modified Lugeon tests are usually linear curve pattern, and the pressure decrease while the discharge increase in pressure-discharge-time curves of single-hole double packer tests, which benefit statistically determining the transmissivity of dominant fracture sets. INTRODUCTIONFractures interlaced in rock masses are major channels for groundwater flow and generally account for the anisotropic and heterogeneous characteristics of permeability for fracture rocks. To describe reasonably the permeability of a fracture rock, the Discrete Fracture Network (DFN) approach and others with similar ideals have been developed. Many methodologies and associate equipment, for instance, the televiewer and the in situ hydrogeological test, have been proposed to investigate the spatial distribution and the transmissivity for different fracture sets, which are two main parameters necessary for the DFN or similar model simulation (Pearson & Money, 1977; Barker & Black, 1983; Hsieh et al., 1985; Bernard et al., 2006; Quinn et al., 2012). However, diverse outlooks for the pressure-discharge curves and the temporal pressure and associate temporal discharge curves often confuse the investigation results by significant deviations on derived permeability (Houlsby, 1976; Zlotnik, 1994; Royle, 2009; Camilo, 2010).Aiming on technical development for in situ hydrogeological tests and fracture investigation, an experimental well site with 10 wells has been established in Heshe in central Taiwan since 2011 (Wang et al., 2011; Song, 2012; Zhan et al., 2013). Extensive geological survey and well-hole scanning by a televiewer provide spatial distributions and outlooks of fractures in detail. Additionally, a series of Lugeon tests, double packer injection tests and pumping tests have been performed to investigate the permeability of fracture rocks, and dominate fracture sets as well. Based on the results obtained from the Heshe site, this study classifies the curve patterns of hydraulic packer tests. The features of fractures involved in packed sections for packer tests are then inspected in detail. Relationship between the curve patterns of hydraulic packer tests and associated features of corresponding fractures in rock are discussed and addressed accordingly."

Jan 1, 2015

By R. H. Watson

A paper read by J. A. H. Church before the Northern Alberta Branch last February described a method of working thick inclined coal-seams from the dip upwards, with the view to preventing fire risk by using water for the stowage of waste workings, and extinguishing a conflagration should such break out, was favorably received; but there was some doubt as to the cost of such a method, as it involves a retreating system, which might prove too expensive for practical adoption. Let us consider a typical leasehold such as we are familiar with in the Rocky Mountains. The leasehold is crossed at one end by a mountain river, which is cut by the outcrop of a seam of coal, 30 feet in thickness, pitching as shown on the drawing herewith, which also shows the general line of the outcrop in elevation through the leasehold, which is two and a half miles long and contains 1,500 acres. The average lift is about 600 feet above river level and drilling has proved that the coalseam can be tapped at a depth of 1,500 feet, 2,000 feet down the pitch from the outcrop in the river, all as shown in the illustration, which is typical enough of our mountain conditions to serve the purposes of comparison of methods. We take up the leasehold and invest $30,000 to pay for drilling and prospecting; $30,000 more for the price of the lease to locator or holder, and say $100,000 to pay for a railway spur (it might cost twice this sum, but we are only comparing two methods in the same location) and "now we are ready to consider equipment and the cost of development.

Jan 1, 1924

By Unknown

With the present-day trend of rising labour costs and a lowering of production efficiency of workmen, it has become imperative that every effort be made to use manpower to the greatest advantage and to mechanize mining as much as possible. During the past few years this trend has gained much prominence in the Porcupine camp. In view of this, the executive of the Porcupine Branch considered that the Mechanical Movement of Muck would be a very timely subject for a Symposium. Accordingly a Committee was formed, with A. K. Douglass, Mine Superintendent for Delnite Mines, Ltd., as Chairman, and the Symposium was held in the Auditorium of the McIntyre Community Building, Schumacher, on March 25th last. Papers dealing with shovel loader and mechanical scraper operation at six of the larger mines of the camp were presented and discussed, and a tabulation was prepared giving data on the machines in operation at a total of eleven mines. The papers and tabulation, reproduced below, will doubtless be of considerable interest to operators of mines in all parts of Canada.

Jan 1, 1948

By L. B. Tsymbulov, N. A. Fedorova

The equilibrium of exchange reaction (Cu20)+[Ni]=(Ni0)+2[Cu] taking place in the course of interaction of metallic nickel-containing copper melts with different oxide melts (Cu20-NiO, Cu20-NiO-Si02, Cu20-NiO-FeO(Fe203)) in the area of their homogeneity has been studied. The studies, based on the known value of equilibrium constants and defined copper and nickel activity indices in metallic melts and equilibrium concentrations of Cu, Ni, Cu20 and NiO, determined the YNio/ycu2o ratios in the oxide melts of the above systems. For the equilibrium between nickel-containing copper and binary oxide melt Cu20-NiO, values of YNiO and Ycu2o were determined both by calculation and experimentally. Based of the data conclusions regarding oxide melts construction are presented.

Jan 1, 2007