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By T Salman

The construction and use of the B.E.T. (gas adsorption) apparatus is described. Examples are given for the determination of large and small surface areas using nitrogen and krypton. Introduction A NY study of the milling of ores from crushing to grinding, classification, and concentration and finally dewatering of the products involves solid particles which are either in contact with a gas or a liquid phase. The surface area of the solid and its characteristics constitute important parameters in all mineral dressing operations. The success of any particular operation is dependent on the interaction of the surface of the solid particles with the gas or the liquid phase. Particle size and specific surface (surface area per unit weight) continue to be important parameters in the flotation research associated with the adsorption of collector molecules or ions on mineral particles, as in the early years of mineral dressing research (1). In order to understand the mechanism of the flotation process, it is essential that the surface properties of the adsorbent be known.

Jan 1, 1965

By K. D. A. Whaley

Abstract -The Captain North Extension deposit consists of five sulfide lenses hosted in cherty and chloritic metasediment that is bounded by quartz-eye rhyolite and laminated rhyolite . Lens 2 consists of sphalerite and galena with silver-rich tetrahedrite in chert. Lens 3 contains massive pyrite, with chalcopyrite and minor gold, gradational to minor pyrite in a chloritic metasediment . The other lenses are unexplored. The sulfides occur as beds, fracture infills, and disseminated grains. Reserves are estimated at 207 555 tonnes grading 7.38% Zn, 2.76% Pb, and 91.81 g/t Ag. The deposit is isoclinally folded, dips steeply west, plunges 50 degrees south, and is faulted out to the north, where drag folding has reversed the plunge. Minor cross-faults contain talc and sericite. High sphalerite but low pyrite abundances result in poor responses to standard electromagnetic techniques. Lens 3, which contains more pyrite than Lens 2, responds better to induced polarization and allows detection. Geochemical anomalies are found in a nearby swamp and stream, but an impervious till cover inhibits the development of soil anomalies.

Jan 1, 1992

By Edgar L. Horner

"The objectives of the Wabush Mines tailings stabilization program are to control dust Ii/t-off and to rehabilitate the disposal area. The evolution of the program started with test plots in 1970, these being continued and expanded upon through 1974. In 1976, a 35-acre vegetation field trial was attempted and failed, part of the failure being attributed to lack of adequate equipment. Subsequently, equipment was purchased and during the summer of 1979-80 extensive areas were treated. The program was also expanded to include the evaluation of chemical and water spray stabilization versus vegetation in areas where shorter-term control is required. In addition, during the summers of 1979-80, spruce bog material was spread over about 100 acres and seeded.The approach to reclamation by vegetation at Wabush is one of soil building. Work to this point indicates that iron ore tailings can be converted to a soil capable of supporting plants. Plans for the Wabush tailings disposal area should make dust lift-off from inactive tailings areas negligible within the next few years."

Jan 1, 1981

By Paul J. Beck

The impact of mining development on the environment can be minimized through comp careful construction and accurate monitoring. Key to meeting these objectives is t information at all stages of design, development, operation and decommissioning. This paper will describe cost-effective means of gathering and managing reliable fiel groundwater flow and surface water regime within and surrounding the mine site, as localized contaminant plumes associated with mine operations, and monitoring ground quality. Recent research has led to the development of inexpensive, easy to install syst sampling/monitoring from different zones within a single borehole. Advances in elect developed small diameter probes and pumps for measuring water levels and taking wat continuous monitoring stations in remote areas can be colldeacttaeldo gaguetrosm aatnidc adlolwyn luosaidnegd from a central facility using telemetry systems powered by direct, battery or solar radio frequency, landline or cellular telephones, and satellite. Two case studies will illustrate the use of datalolgagregres sacnadl et eblaesmient rwyi dien mao nitoring sc and the use of multilevel samplers for managing a contaminant plume.

May 1, 2004

By C J. Coveney

This paper, after a brief introduction to the mineralization and structure in the mine area, outlines the methods now being employed for grade control at Bethlehem Copper Corporation. Sampling, subgrade drilling, blasting and the actual outlining of the ore are among the topics covered. The paper concludes with a summary of the results obtained, showing a reduction in dilution and an improvement in the grade of the copper ore going to the mill. Introduction T HE Bethlehem property is located in southern British Columbia in the Highland Valley about 30 miles southeast of the town of Ashcroft. The property is located within the Guichon batholith. The rock comprising the batholith is a massive, coarse-textured diorite, which, at Bethlehem, has been intruded by a younger quartz diorite, porphyries and breccia, referred to as the "Younger Complex." Mineralization, consisting of chalcopyrite and bornite with minor pyrite and molybdenite, occurs as disseminations, fracture fillings and coarse blebs. The ore zone lies close to the Guichon -Younger Complex contact where, prior to the development of the breccia, the rocks were shattered and jointed. Subsequent mineral

Jan 1, 1965

By K. D. A. Whaley

The Captain North Extension deposit consists of five sulfide lenses hosted in cherty and chloritic metasediment that is bounded by quartz-eye rhyolite and laminated rhyolite. Lens 2 consists of sphalerite and galena with silver-rich tetrahedrite in chert. Lens 3 contains massive pyrite, with chalcopyrite and minor gold, gradational to minor pyrite in a chloritic metasediment. The other lenses are unexplored. The sulfides occur as beds, fracture infills, and disseminated grains. Reserves are estimated at 207 555 tonnes grading 7.380/0 Zn, 2.76% Pb, and 91.81 g/t Ag. The deposit is isoclinally folded, dips steeply west, plunges 50 degrees south, and is faulted out to the north, where drag folding has reversed the plunge. Minor cross-faults contain talc and sericite. High sphalerite but low pyrite abundances result in poor responses to standard electromagnetic techniques. Lens 3, which contains more pyrite than Lens 2, responds better to induced polarization and allows detection. Geochemical anomalies are found in a nearby swamp and stream, but an impervious till cover inhibits the development of soil anomalies.

Jan 1, 1992

By J. Lu

The impact of acid treatment in agglomeration/acid curing on copper extraction and acid consumption was investigated with respect to acid dosage and moisture. Without the addition of water, no agglomeration occurred. At an acid dosage above 15 kg/t, the acid was not completely consumed during acid curing. With the addition of 6.2% water, the particles agglomerated together. Copper, iron, magnesium and manganese were dissolved as sulfates and enriched in the fine fraction of the ore. The copper extraction and net acid consumption increased with increasing acid dosage. The copper extraction for acid curing with the addition of 6.2% water was higher than that without the addition of water due to the improved permeability and the increase in the contact with acid-soluble copper. During acid curing, the reaction of sulfuric acid with muscovite, abite and nacrite mainly took place on the surface of the particles while the reaction of sulfuric acid with clinochlore occurred not only on the surface but also inside the particles.

Jan 1, 2007

By P. Latostenmaa, O. Forsén, M. Lundström, J. Aromaa

The history of electrolytic copper production in Finland is closely connected with the industrialization of Finland and events of the Second World War. Production of cathode copper by electrowinning from the processing of Outokumpu ore started in 1913 based on the Hybinette nickel process, however due to the poor performance of this process, the plant was closed in 1929. Outokumpu commenced copper smelting at Imatra in eastern Finland in 1936 producing blister copper for refining outside the country. Due to the threating military situation, a new electrolytic copper refinery was built in 1941 at Pori in western Finland to refine the anodes. This was the first electrolytic copper refinery in Finland. It was built with 108 cells having a capacity of 12,000 tonnes/y. In addition, the smelter was relocated to nearby Harjavalta in 1944–1945. To fulfill the war reparations included in the peace treaty with the Soviet Union, a doubling of the smelter capacity was realised, with the Pori refinery capacity increasing to 20,000 tonnes/y in 1946 by adding additional cells. The cornerstone of Finnish metallurgical technology — Outokumpu flash smelting — was invented with the new technology commissioned at Harjavalta in 1949 replacing the electric furnace and providing a further increase in copper output with subsequent enlargement of the refinery. By 1963, the plant consisted of 380 cells with a capacity of 48,000 tonnes/y of cathode copper. The Pori electrolytic copper refinery has operated continuously since 1941. Commencing in 2004 the Pori refinery has been part of the Boliden group of Sweden. The most recent plant upgrade was in 2007 with the installation of permanent cathode technology. In 2017, the production of the Pori refinery was 133,000 tonnes of copper cathode, 2,300 tonnes of nickel sulphate, along with 66 tonnes of silver and 4.6 tonnes of gold. This paper describes these outstanding achievements. INTRODUCTION In 1809 the Kingdom of Sweden was defeated by the Russian Empire in the Finnish War, and Finland was annexed by the Russian Empire as the autonomous Grand Duchy of Finland. Finland’s commercial and industrial interests were developed to serve the Empire’s needs. Finland had raw materials, but at the start of the 20th century Finnish industry was based on the use of wood as raw material and agricultural products. The mining industry was only a few percent of the country’s industrial production.

Jan 1, 2019

By C. Cristonffanini, S. Nazari

"In the past, simulation was considered to be an offline tool disconnected from plant operation. Advancements in the computation power combined with utilizing physics and chemistry sciences have allowed us to significantly improve the modeling and simulation technology for mining and mineral processing. This paper investigates the benefits of first principle models and simulation by connecting them to real time operation. Process data are connected to high fidelity models executed in parallel to the operation. In recent literature, this concept is known as Digital Twins. The Digital Twin is used for various purposes such as optimization, virtual instrumentation and condition monitoring. Using IDEAS™ simulation software we are able to construct a digital twin for different equipment inside a mineral processing plant. Two case studies for building a digital twin for the primary hydrocyclone feed pump and thickener underflow are presented. Using the pump’s model, a digital twin is developed and is installed in a gold extraction plant that is able to infer the slurry density in real time. Additionally, it is used for detecting sanding in the pipes and impeller condition monitoring.INTRODUCTION Since the eighties, thanks to advances in computation technologies, computer based simulation of processes using first principle models has become a well-known engineering tool for various industries. As our understanding of processes has increased, their representative models have become more realistic and more sophisticated. Due to this increase of accuracy, use of simulation is becoming more fundamental in process industries. The main goals to use accurate simulation is to decrease the engineering and construction cost, optimize the process design and improve the operation performance by decreasing operation cost and increasing efficiency. The term Digital Twin was first introduced in 2010 by NASA (Shafto et al., 2012) in aerospace industry. Subsequently, the concept quickly spread through other industries. As of today, no standard organization has provided an official and unique definition of Digital Twin for process industries. However, there are three important aspects that are common throughout various descriptions. When simulation is core functionality of the process (1) along the entire life cycle of the plant (2) with direct linkage to operation (3), it is called that process has a Digital Twin. According to Gartner, the concept of Digital Twin has elected as fourth most important disruptive technology for the year 2018 (https://www.gartner.com/, 2017)."

Jan 1, 2019

By E. Bratygin, G. Gazaleeva

"The article describes the analysis of methods and criteria of selectivity of optimal ore preparation schemes. Traditional criteria based on study of physical-mechanical properties of ores give the comparison of obtained figures with a reference standard or statistic data and the selection of the ore preparation scheme is made on a basis of a similar scheme from the existing production.Further on estimation is given to different criteria of the crushing selectivity, the new criterion is offered, the definition of which is done by results of an optical microscopy– the estimation of a valuable mineral release degree. The final estimation of the crushing process selectivity L? is performed by a calculation of a ratio of the valuable mineral free grains quantity in a desired size grade of a crushed material to the valuable mineral free grains quantity in a desired size grade of a raw product.Besides, optimality assessment of using the specific crushing unit is preliminary performed according to a maximum crushing degree of a material, however, the priority is given to the maximum selectivity criterion. The check of the proposed criterion was done when comparing the crushing of niobium bearing ores of the Vishnevogorskoye deposit in cone inertial and centrifugal impact crushers. Different operation modes of crushers were also checked. The comparison of the crushing selectivity criterion L? showed that the centrifugal impact crusher (CC) has the value of the selectivity criterion lower than the cone inertial crusher (CIC). For the crusher CC the criterion L? is 0.82 – 0.87 units, whereas for the crusher CIC – 1.43-1.755 units. The best crushing mode for the crusher CIC-300? is as follows: turning angle of debalance is 120°, peripheral speed of a cone rotation – 1,420 rpm, specific energy consumption – 6.99 kW?t/t.INTRODUCTIONIt has been shown that the most efficient techniques of mineral raw materials disintegration are selective crushing enabling to produce liberation of particles at maximum use of destruction techniques by borders of minerals cleavage. These days, such techniques are usually called special disintegration techniques (Jankovic & Valery, 2015), and they are used in 3–4 crushing stages. The selection of optimal crushing techniques is performed based on the following main parameters:- degrees of crushing, calculated based on granulometric features of raw and crushed products;- selectivity criterion defined according to useful mineral release and slime ability degree; and- traditional criteria (Gazaleeva et al., 2015) of choice based on study of physical-mechanicalproperties of ores gives the comparison of obtained figures with a reference standard or statistic data and the selection of the ore preparation scheme is made on a basis of a similar scheme from the existing production."

Jan 1, 2016

By T. J. Bruce, G. E. Agar, R. Stratton-Crawley

"A technique by which the design of a flotation circuit may be optimized is described and examples of the application of this methodology are given.Three interrelated criteria are defined and the application of these criteria to the selection of the optimum residence time for each stage of a flotation circuit is demonstrated. The criteria are:(1) Add no material to the concentrate that is lower in grade than the feed to that separation stage.(2) Maximize the difference in recovery between the desired mineral and the gangue.(3) Maximize the separation efficiency.Three independent systems were examined experimentally and it was shown that application of any of the criteria yielded similar results.It was demonstrated how the application of rate measurements (Criterion #2) could lead to the selection of a set of optimized times for several stages in a flotation circuit and that these could in turn be used to simulate the results of a locked cycle test. The predictions were checked against the experimental results from a locked cycle test and there was substantial agreement between the predicted and observed results."

Jan 1, 1980

By Andrew Bamber

The mining and beneficiation of minerals is the second largest end-use of electrical power on the planet, and comminution is by far the largest single contributor to this. Several jurisdictions, including British Columbia, have, in response to concerns about greenhouse gas emissions and climate change, adopted energy conservation legislation, including carbon taxes, carbon trading and conservation incentive schemes. Key to achieving conservation objectives is firstly an understanding of usage metrics across the various unit operations in the sector, and secondly an understanding of the conservation potential represented by available technologies and approaches in reducing end-use. This paper presents the results of a recent utility-funded study on energy use metrics and conservation potential at large open pit mines which are typical of the sector in BC.

Aug 1, 2013

By Michael Chender

Emerging Equity Sources ? Larger IPOs ? China Inc. ? Other sovereign wealth funds ? New funds and higher allocations ? Private equity

May 1, 2010

By Heather Budney

Objectives 1. Evaluate the effectiveness of ON?s EA processes using criteria from the EA and policy sciences literature. 2. Recommend improvements to the EA processes and draw lessons from the ON case for the consideration of other jurisdictions. Evaluation Process 1. Chose criteria ? 14 primary criteria (Wood 2003) ? Subcriteria from Wood (2003) and Lasswell (1971) 2. Gathered information ? 6 key informant interviews ? Published literature, policies, legislation 3. Assessed criteria and formed Recommendations

May 1, 2008

By Piotr Litwa

The paper focuses on actions aiming at improvement of work safety in mines, particularly in those extracting hard coal, taking into account the characteristics of natural hazards in Polish underground mining and the reasons of mining disasters connected with those hazards. It refers to conclusions addressed to scientific and research centres, drawn during last decade by Commissions appointed by the President of the State Mining Authority in order to investigate reasons and circumstances of incidents, which till now, could not have been accomplished because of financial reasons. Furthermore, the paper presents basic assumptions of the Strategic Research Project Improvement of work safety in mines, announced by the National Centre for Research and Development at State Mining Authority?s President request.

Aug 1, 2013

By Robert B. Parsons

"Effective January 1, 1990, mines in British Columbia are subject to a new provincial mining tax statute, the Mineral Tax Act. Under this Act, mines are subject to a two-tier tax system, with a minimum tax payable on ""net current proceeds"" and a higher tax paid on net income. For many mines, the present value of tax paid under the new rules should be comparable to the amount paid under the old rules. Earlier cash payments could pose difficulties, particularly for smaller mines, but existing producing mines could benefit in the short-term.IntroductionEffective January 1, 1990, British Columbia has replaced the provincial mining tax regime under the Mineral Resources Tax Act with a new system under the Mineral Tax Act. The new rules borrow some ideas from other provinces (New Brunswick's two-tier concept, and Saskatchewan's indexed costs) with a view to levying a tax that is fairer to both the producer and the province."

Jan 1, 1990

By Bruce Peberdy

Outline ?Building Systems ?Climatic Effects ?Thermal Effects ?Building Components ?Building Materials ?Structural Deterioration ?Maintenance Considerations

Nov 1, 2011

By Li. L.

Backfilling has become a popular solution in underground mines around the world. It reduces environmental impact of mining industry and improves ground stability. In most cases, backfill has a high water content so that it can be delivered by pipes from a backfill plant on ground surface to underground stopes. Upon deposition in the stope, the backfill tends to consolidate under its own weight, leading to a generation of excess pore-water pressure. To avoid excessive pressure and protect the backfill barricade installed at the base of the stope, the backfilling of the stopes is usually divided into two stages: plug pour and backfill body pour. The interruption of backfilling operation is undesirable as it slowdowns the mining productivity, and sometimes causes pipe clogging, leading to unexpected increase in manpower cost and further reduction in mining productivity. The backfilling interruption time may be reduced, even eliminated if the drainage of backfilled stopes is sufficiently improved. This paper presents an application of wick drains, a material commonly used in civil engineering, to mine backfilled stopes to help accelerating the drainage. A protocol is proposed for installing the wick drains in a mine stope to be backfilled. Numerical simulations were made, showing that the drainage of the backfill can significantly be improved by the introduction of wick drains. The application of wick drains in mine backfill can thus be considered as a promising technique and merits deeper and more detailed investigation.

Aug 1, 2013

By Robert B. Parsons

"In all likelihood, Canada's mining industry would be adversely affected by corporate tax reform proposals actively being considered by the Department of Finance in Ottawa. When the next set of proposals for lax reform is released later this year as promised by Finance, the mining industry had better be prepared 10 take a hard look.IntroductionTwo federal budgets ago, in May 1985, Finance Minister Wilson tabled budget papers that were more massive in terms of volume than most federal budgets. Buried in this mass of documentation is a discussion paper entitled ""The Corporate Income Tax System-A Direction For Change"". When the discussion paper was tabled over one year ago, reaction from the business sector was almost nonexistent. By and large, the paper was regarded as nothing more than one more federal publication of mild academic interest.But, recent events suggest that this discussion paper for corporate tax reform could be the cornerstone for a series of changes to the tax laws which would have more profound and widespread effects for all sectors of the economy than any reform since 1971 . No industry in Canada can afford to ignore the movement afoot in Ottawa for corporate tax reform."

Jan 1, 1986

By R. S. Boorman, L. J. Surges

"Ore reserves at Brunswick Mining and Smelting totalled 101(106) tonnes grading 97 grams tonne-1 silver at the end of 1981. Silver is recovered as a byproduct in the copper, lead and bulk concentrates and is lost to the zinc concentrate and plant tailings. Recovery of silver for the year 1981 was 58,5%. The loss of potential revenue is in excess of Cdn $50(106) year-1 at current silver prices and milling rates.Silver is known to occur in solid solution in galena and as tetrshedrite. Evidence indicating the identity and significance of a third silverbearing mineral assemblage is reviewed and the distribution of silver losses is detailed. Characteristics of each the carrier which may be responsible for observed distribution, including size, surface quality, liberation and composition are considered, and the third carrier is shown to have possible implications for improved silver recovery by other Canadian producers as well as by Brunswick Mining.Silver tetrahedrite tailings distributed tailings and losses occur as coarse, free and as very fine unliberated galena in losses of the third carrier are between the zinc concentrate and are concentrated in the finest size fractions. Process alternatives for enhanced silver recovery by physical and chemical means are reviewed."

Jan 1, 1983