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By J. A. Drozdiak, A. Bamber

In this paper we examine, through pilot-scale testing, the possibility of operating a circuit comprised of two stages of HPGR comminution, followed by grinding through a horizontal stirred mill. In order to assess whether the novel circuit design could achieve the reduced energy requirements indicated in the literature, two more-established circuits, a cone crusher / ball mill and an HPGR / ball mill, were examined using a combination of testing and flowsheet simulation. The results showed that, based solely on the specific energy requirements for comminution, the HPGR / stirred mill circuit achieved a reduction of 9.2% and 16.7% over the HPGR / ball mill and cone crusher / ball mill circuits, respectively.

Jan 1, 2012

By S. Y. Mostowy, P. W. M. Shibley

"When Texas Gulf Sulphur Company discovered the Kidd Creek ore body in 1964, a crash program began almost immediately for the design and construction of a modern concentrator. It was necessary to mill two distinct ore types; one containing copper and zinc, the other lead, silver and zinc minerals. The final concentrator design was to handle 9,000 tons of ore daily in three circuits. One circuit was to treat copper-zinc and another lead-zinc ore exclusively on a permanent basis. A central circuit was designed with adequate flexibility to treat either of the above ore types in accordance with planned mining schedules. Ecstall Mining Limited, a wholly owned subsidiary, now operates the mine and concentrator complexes for Texas Gulf. The mine is located 15 miles north of Timmins and the concentrator 15 miles to the north-east along Highway 101. The ore is hauled from the mine to the concentrator over a 17-mile railroad. Initial milling operations began in November, 1966.1 - ABSTRACTThis paper deals with bulk reagent handling at the Kidd Creek concentrator. The reagent section at Kidd Creek has operated excellently since milling began in 1966. The bulk handling techniques are satisfactory. They have contributed substantially to good working conditions, economical practices and metallurgical efficiencies. The bulk handling features described should be considered in existing and proposed concentrators."

Jan 1, 1970

In-Country Business Development Agenda ?Siting/Permitting/Operational Planning ?Securing, maintaining, enhancing social license to operate ?Biodiversity conservation and ecosystem services ?IFC Performance Standards ?Environmental, Social, Risk Governance (ESG) ?Climate change plan

Aug 1, 2013

By T. A. Postolski, A. J. Sinclair

"Abstract - Where block (selective mining unit) grade distributions can be determined, the effect of average random errors of block grade estimates on metal recovery can be evaluated quantitatively. That is, for a given estimation error and cutoff grade, it is possible to calculate the quantity of metal that is lost as a result of misclassifying ore blocks as waste, as well as the dilution that ensues from misclassifying waste blocks as ore. Example calculations using a computer program GAINLOSS and realistic block grade distribution parameters for both a porphyry-type deposit and an epithermal gold deposit illustrate some fundamental relations that are important in quality control of estimation and in reconciliations concerning a comparison of ore estimates with production.Where the cutoff grade is on the lower tail of the grade distribution, metal arising from dilution can be much less than metal lost through misclassifying ore as waste. Hence, average grade of milled material could possibly be higher than expected (estimated) and tonnes milled will be smaller than estimated.Where the cutoff grade is on the higher tail of the grade distribution, tonnes arising from dilution will be greater than tonnes lost by misclassifying ore as waste. Thus, tonnage mined will be greater than estimated and the average grade milled will be less than estimated.The software GAINLOSS permits rapid comparison of the tonnes and average grade for all blocks selected as ore for a variety of levels of block estimation errors. These comparisons can be incorporated in a financial analysis to evaluate whether or not it is worthwhile to improve a high, average block estimation error to some lower value."

Jan 1, 1998

By Robert J. McCarthy

Mining has a record of achievement in developing and adopting new technology to facilitate the extraction of increasingly challenging resources. Certainly larger, or more capable, mining equipment has allowed mining companies to mine mineral deposits at lower unit costs; however, there has also been the advent of computerized systems that aid in the management and tracking of mining operations. Unfortunately, the latter computerized systems have not always had the success anticipated with their implementation. This paper explores the view that increased transparency of the planning and operating cycle in a mine, as provided by certain computerized systems, can result in some resistance from those whose work becomes ?exposed?. Examples are drawn from industry-leading technologies for both mine management and reconciliation that illustrate the issues and challenges that result. The adoption of appropriate change management principles is suggested as a best practice in planning and mitigating the challenges in implementing technologies which increase transparency in the mining environment.

May 1, 2011

By Kadir Sariiz

Abstract - The Akçayir-Yürükakçayir Miocene-Pliocene basin in the Central Anatolia hosts ancient lacustrine sepiolite deposits. The succession in this basin consists of conglomerate (Yürükakçayir conglomerate), clayey and silty limestone, dolomitic marl, sepiolite beds and lenses, and dolomitic limestone (Kepeztepe formation). The main impurities within the sepiolite rock are dolomite, opal-CT, calcite, smectite and feldspar as sepiolite + dolomite and sepiolite + opal-CT are the main mineral assemblages. Smectite and feldspar are thought to be of detrital origin. Calcite is found as a secondary filling in root tubes and casts. Sepiolite samples studied display root-marks and root tubes, soapy and massive structure indicating direct precipitation. Sepiolite deposits probably formed at a pH of 8 to 9, and Mg+2 and SiO2 concentrations in moderately saline environments of internal facies of an alkaline lake.

Jan 1, 2000

By M. Leroux, S. R. Rao, J. A. Finch

"Poor Pb/Zn selectivity during Pb flotation in laboratory tests on a Mississippi Valley-type Pb/Zn ore was traced to a pH effect. In the pH range 9.5-11 sphalerite floated readily without copper activation. Compared to sphalerite flotation with copper activation this procedure gave equivalent selectivity but reduced flotation rate.Possible mechanisms of this sphalerite flotation without copper activation are discussed. Activation by Fe(OH) 2 is suggested, the Fe++ions being derived from superficial oxidation of pyrite in the ore.INTRODUCTIONGalena and sphalerite commonly occur together. The usual practice is to float galena first followed by the flotation of sphalerite after activation with copper (II) sulphate. If ores contain pyrite it is depressed by maintaining an alkaline pH (9- 10) and using NaCN as depressant.In flotation tests with a Pb/Zn ore from Polaris selective flotation of galena could not be achieved consistently as a considerable amount of sphalerite, even though unactivated, floated. A systematic study was carried out to determine the cause of this problem. This led to the unexpected finding that sphalerite floated in the alkaline pH range 9.5-11.0 without preactivation with Cuso 4 . This paper describes the results of this study and discusses a possible mechanism of the flotation of sphalerite."

Jan 1, 1987

By J. A. R. Faucher

"Autogenous grinding may be an efficient and economical solution to your ore comminution problem.An important potential economic advantage of autogenous mills results from the availability of very large capacity units.Autogenous grinding could be more economical in terms of both capital and operating costs.Satisfactory pilot plant testing and thorough economic evaluation are required for a sound decision in comminution plant selection.INTRODUCTIONMankind's first weapon was probably the wooden club, but men soon learned to shape, smooth and polish stone for tools and weapons by pounding and rubbing them with sand and water. It was only about four thousand years ago that rocks were first broken to concentrate, smelt and return the metals they contained. In spite of our recent great technological advances we still break rock in essentially the same manner that was used thousands of years ago - by pounding, rubbing and squeezing - and we still waste much energy and metal in the process"

Jan 1, 1969

By Pierre C. Vieillescazes

MIGA: Unique Multilateral Risk Mitigator ?A World Bank Group agency established in 1988 to promote and facilitate sustainable foreign direct investment in emerging coufacilitate countries ntries (north(north--south and southsouth south--south) ?Guarantees equity and debt and many other types of investments against non-commercial risk. ?Can cover the following type of risks: ?Expropriation ?Breach of Contract ?Currency Transfer and Inconvertibility ?War and Civil Disturbance ?Non-Honoring of Sovereign Financial Obligations

May 1, 2010

By Michael Fuller

Roadmap ? Examples of Partnership from UBC ?? Event Sponsorship ?? Recruitment & Connections ?? Opportunities ? National Recruitment Survey Results ? Conclusion with Key Points Event Sponsorship ? Annual Canadian Mining Games competition ?? 160 senior mining engineering students, from 10 universities ? Field Trips ?? 2nd year: Open pit ? Highland Valley Copper ?? 3rd year: Underground ? Myra Falls, Quinsam Coal ?? 4th year: Self-organized ? Chile, China, Poland, Brazil

May 1, 2008

By Carl Sonnen

Reading the newspapers, you will know that opposition to ratification on economic grounds always points to the view that action will result in major price increases for energy (to both industry and households) with consequent severe losses of energy production and a loss of competitiveness for energy-intensive producers (i.e., in your kinds of industries). You might think of this as the ?carbon tax? fear, and you should note that many of the initial policy development experiments included variations of this theme. Analysis reported in late 2000 and into early 2002 reported reductions in energy production in the long run of between 10% and 20%. At the upper end of that view, these were the kinds of numbers reported in the Industry Canada study ?leaked? to the Press last week. The consequences of this approach included significantly uneven negative effects for some provinces (e.g., Alberta, but also Saskatchewan and Newfoundland). It had been agreed by the First Ministers of Canada, however, that the policy should not yield those results so development in recent months has focused on eliminating sector and therefore provincial ?sore thumbs?. Although an emissions trading system, which represents this type of approach and directly impacts costs of production, continues to be featured in the new or current policy and is applied to the Minerals Industries among others, it is designed to be implemented in such fashion that the costs are more moderate than before. And because the industries covered by permits are almost all price takers, there is no device for moving an increased price signal forward to ?consumers?. What this does do is even out negative effects among sectors in the economy and for provinces, but at the expense of government financial results.

Nov 1, 2002

By Gordon. I. M., J. Blackshaw

"The wet part of the Hollinger mill is housed in two buildings, the grinding plant and the treatment plant. In the grinding plant there are four 7xl5 ball mills which grind the ore to 60 per cent through 200 mesh. There is also one 7xl5 ball mill which grinds table concentrate to 9 5 per cent through 200 mesh.The primary classifier overflow is pumped to the treatment plant where it passes over shaking tables, producing a concentrate and a tail. The concentrate pulp is pumped to the grinding plant for secondary grinding. The secondary classifier overflow is pumped back to the treatment plant where it is thickened in two 40xl 5 tray thickeners and agitated in four 20x24 mechanical agitators arranged in series of two (with 2 spares).The table tail pulp is thickened in nine primary 40xl5 tray thickeners (with 2 spares). The thickened table tail pulp and the concentrate agitator discharge pulp are mixed and pumped to four rows of 15x45 pachuca agitators, arranged in series of five tanks.The pachuca discharge pulp is divided. The smaller part goes to two rows of 3-step decantation using 40xl5 tray thickeners (with 2 spare rows). The larger part goes to six 14xl6 drum filters. The repulped primary filter cake and the thickened pulp discharged from the decantation rows are fed to eight 14xl6 drum filters. The secondary filter cake is mixed with water and pumped to the tailing line."

Jan 1, 1968

By George Carico

Research and related demonstration projects are being conducted in West Virginia on both existing and former coal surface mine lands to determine potential post-mine land re-use options that offer the greatest likelihood of future benefit and success. Examples of projects include renewable energy considerations that incorporate solar, wind, and/or biomass options, and contain components designed to educate business, government entities and the local community on renewable energy options and potential opportunities Multiple property re-use options are being researched and evaluated, based on site-specific conditions and characteristics, including infrastructure, local community needs and regional economic conditions. Re-use options being explored include innovative uses and needs, such as specialty housing, unique business and industrial needs, and an extensive variety of recreational and small business opportunities that best fit the specific needs of the local community and regional economic structure.

Aug 1, 2013

By C. W. Eggert

"The idea for this talk came to me last year when I was attending the Canadian Gold Metallurgists Meeting. I talked about it to a friend of mine who is an authority on mineral dressing, particularly the theoretical end of the business. He remarked that this was an excellent technical note, why don't you write it up. This is what I have for presentation this morning. I hope in presenting this type of idea in this way it is in keeping with the tradition of the Canadian Gold Metallurgists which was to function on a not too sophisticated level and where operators could get together and trade ideas in an informal way.My basic thesis is that it should be possible to evaluate screen analyses by the application of the standard statistical probability theory. In any statistical analysis the sample is the first consideration. If we look at existing methods of size evaluation we find it is usually based on the fact that a given particle will pass one square aperature and not another. One system of standardizing how these aperatures will be set up is based on Rittenger' s work with the ratio of hole sizes proportional to the square root of 2. Keeping in mind the limitation we have accepted this as our method of 11 sizing"" in attempting to apply standard statistical methods to screen analysis."

Jan 1, 1968

By C. Paulo, W. N. Wheeler, M. Kalin, M. P. Sudbury

Many researchers have tested the addition of various phosphatic materials, including Natural Phosphate Rock (NPR), to mining wastes. It was assumed that iron in the waste would form FePO4 precipitates, restricting oxygen access to pyrite surfaces and reducing oxidation. Phosphate additions were based on stoichiometry (phosphate mass to sulphide content of waste). Although some interesting, positive results were obtained with low dosages, these were considered accidental, not having followed the expected stoichiometry. In 1991, we began experimenting on tailings and waste rock with NPR, postulating that if chemo-lithotrophic microbes on the mineral surface accelerate oxidation, then heterotrophic (oxygen-consuming) microbes would reduce oxidation. All wastes with NPR produced effluents with elevated pH and low metal acidity. Later, microscopic investigations of the rocks found an organic layer on the mineral surface, which was confirmed by independent research organizations repeating experiments with very low NPR mass additions to sulphidic wastes. In 2013, heterotrophs were identified and quantified as they grew on German lignite with NPR. These data conclusively showed that the development of heterotrophic biofilms is a consequence of adding waste NPR leading to a reduction of sulphide oxidation and improved effluent from sulphidic mining wastes. We document our gradual understanding of the effects of NPR on the reduction of sulphide oxidation, covering 23 years of research.

Jan 1, 2014

By Md. Rashedul Islam

Magnetic data was collected from the Yeoju historical sites using the fluxgate gradiometer through six sites & several grids. We measured the vertical gradient by the FM256 Fluxgate gradiometer. The readings were logged every half meter. The obtained data were processed and treated to introduce a high quality magnetic image. The gradiometer results defined various positive and negative magnetic anomalies, which revealed the existence of several archaeological features of different shapes and sizes. The study of the process magnetic images give us a concept that the subsurface features are caved shape stone chamber tombs, burial mounds, deep room structure, Yeoju mausoleum, pagoda?s square foundation stones, walls etc. All these are superior work of early Goguryeo inheriting orthodox Silla style. So, the study area may have great archeological interest.

May 1, 2009

By Patrick Chabot

Ce document présente une méthode hybride de long trou favorisant une méthode de minage initiale par chambre-magasin et complétée par une méthode de minage long trou. Cette méthode a été adaptée suite à plusieurs facteurs tels qu?une géologie complexe, une rareté de mineur d?expérience et un haut taux de roulement de main d?oeuvre spécialisée. Cette méthode a permis d'excellents résultats par rapport à la dilution. De plus, la récupération de pilier à haute teneur par forage long trou sera expliquée. Cette méthode permet aussi de récupérer le minerai qui est resté accroché dans les chantiers chambre-magasins. Introduction : La mine Géant Dormant est une mine filonienne d?or située à environ 80km au nord de la ville d?Amos au Québec. Elle est en opération depuis 1988 et à la fin de 2007, elle a produit près de 885 000 onces d?or à partir d?environ 2 400 000 tonnes de minerai pour une teneur moyenne d?environ 11,5g /t Au. Cette mine est la propriété d?IAMGOLD Corporation depuis l?acquisition de Cambior par cette dernière au mois de novembre 2006. Elle emploie 151 employés permanents et environ 41 entrepreneurs.

Feb 1, 2008

By A. J. Williams, W. H. A. Timm

"Lake Dufault Mines, Limited, is located north of Noranda, Quebec, and is a producer of copper and zinc concentrates. Various papers have been given on the mill design, construction and operation. 1, 2This paper is intended to describe the application of computer control to the Lake Dufault milling process. A brief history and description of the plant flowsheet will be given, followed by the reasons for installing the computer and the development of the program up to its present use. The success attained to date, comments on economic justification and future plans will also be given.HISTORY AND FLOWSHEETThe Lake Dufault ore body was discovered in September, 1961, and the mill commenced production during August, 1964. The rated capacity of 1,300 tons per day was reached by October 1, 1964. In milling the Lake Dufault ore, many metallurgical problems have been encountered, mainly due to wide and rapid variations in mill heads and oxidation of the massive sulphide ore. However, flexibility in plant layout and the incorporation of up-to-date instrumentation have facilitated its processing."

Jan 1, 1969

By M. P. Amsden

"Ecstall Mining Limited, a subsidiary of Texasgulf, Inc., Operates the Kidd Creek Mine, Concentrator and Zinc Plant at Timmins, Ontario. Two different ore types are mined and milled to produce concentrates of copper, zinc, lead and tin. The ores are processed at the Concentrator in three separate individual milling circuits, each with the capacity to treat up to 3500 tons per day. Two circuits treat copper-zinc ore 1t an average combined rate of 6500 tons per day and the third circuit treats 3500 tons per day of silver-lead zinc ore. Conventional crushing, grinding and flotation procedures are followed. The purpose of this paper is to describe Ecstall's experience with rubber mill linings in the grinding circuits.CrushingBoth ores are crushed to minus 6 inches at the Mine and delivered by rail to the Concentrator where they are reduced by secondary and tertiary crushing to minus 5/8 inch.GrindingThe crushed ores are prepared for selective flotation by grinding with rod mills and two stages of ball milling. flotation circuit middling products are reground in regrind mills prior to further treatment. A typical flowsheet of one of the grinding circuits is shown in Figure 1.All the grinding units are Allis-Chalmers Mills. The rod mills are 10 1/2 feet diameter by 16 feet long. Both the primary and secondary ball mills are 12 feet diameter by 18 feet long and all regrind mills are 6 feet diameter by 12 feet long. The primary mills are charged with 1 13/16 inch forged balls. Secondary mills are charged with 1 1/2 inch forged balls and the regrind mills are charged with 1 inch forged balls. All cyclones are Kreb units. The primary cyclones are Dl5B hydrocyclones, the secondary cyclones are D6B hydrocyclones and all regrind cyclones are D6B hydrocyclones."

Jan 1, 1974

By Michael Davies

Mined Material Management Meeting or Missing the Mark? o you agree that we have the technology to consistently design robust M3 facilities? ?YES your experience do these M3 facilities perform as expected during operations? ?USUALLY hat can be done to improve performance, e.g. better communications between project and operating teams, discontinuity between design and operational input by designers, others? ?UNDERSTANDINGWHY THINGS GO WRONG an we identify the key characteristics of ?good M3 facilities?, i.e. ones that are performing well? Can we identify ?good M3 facilities?, i.e. ones that perform well and can be held up as examples? ?WITHOUT QUESTION?? your opinion, for what reason do they not perform as expected? ?NO SINGLE REASON??..

May 1, 2010