Search Documents

By J. D. Stinnette

Traditionally, airflow requirements for diesel equipment operating in underground environments such as mines and tunnels were determined by multiplying the vehicle power by a ventilation rate that was either mandated by regulations(s) or determined empirically from known quantities. In some cases, utilization factors were further used to adjust (reduce) the total airflow calculations for a diesel equipment fleet. However, in light of the drastic reductions to diesel equipment emissions mandated by the US EPA Tier IV and EURO Stage 4 regulations, there is currently a great deal of uncertainty in the underground mining industry among those responsible for the ventilation of planned new mines or the expansion of current mines. Tier IV engine standards mandate a reduction of DPM and NOx of approximately 95%, but can ventilation rates at mines with Tier IV equipment (or equivalent) really be reduced by a factor of twenty? This paper outlines some of the factors that affect the airflow required for the ventilation of modern diesel-powered equipment and examines how they can be applied in determining a reasonable ventilation rate for Tier IV compliant equipment operating in subterranean environments.

Aug 1, 2013

"ChairmanThis part of the discussion is intended as an exchange of information between those who have installed rubber liners in their mills and a means of others to get information that may help them decide if rubber liners would be applicable to their mills.To start the discussion and to relate it to the previous section of this symposium Mine Equipment Co. Ltd. have supplied some graphs that will give some idea of the noise suppression that may be expected from the u.se of rubber liners instead of steel. The figures used in preparing the graphs came from installations of rubber liners in Sweden.L. Strah - Mine Equipment Co.The graph, Figure 1, shows on the bottom the octave band range. The noise level generated by the steel liners is represented by the dotted line and lies within the shaded area where it is considered that hearing damage may result. The solid line represents the noise level generated by rubber liners in the same mill and you will see it is below the shaded area. Although it is not marked on the graph I think the decibel range is from 7 5 to 115. The next one, Figure 2 which shows the relative noise levels generated by steel balls and pebbles with both steel and rubber liners shows the decibel range."

Jan 1, 1968

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

By Chris M. Healey

"The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from underground workings returned extremely high values, up to 12851 g/t (375 oz/T) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.In the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/T) gave extremely good results. In the third case, however, indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results.The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this data base, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

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 Terry McNulty

"Previous papers (McNulty 1998 and 2004) have dealt with the causes of successful and less successful achievement of design production rate by new processing plants in the minerals industry. Examination of many case histories has allowed the construction of curves or profiles that represent projects with similar characteristics that equate to differing degrees of care exercised during the project development phase. Simplistically, decreasing care is reflected by increasing risk and a heightened likelihood of poor technical and/or financial performance.This contribution provides an update, including recent case histories, and presents a modified Series 1A curve that includes the best 23 case histories, out of a total of 81 examined, or 28%. This is done to show that some very carefully developed and executed projects can ramp-up quickly and that owners of new projects should avoid being too pessimistic in projecting early cash flow if they are certain that they have done their homework. The role of metallurgical process development in the reduction of project risk is discussed and several financial analyses are presented that express the potential monetary value of a well-designed and professionally executed metallurgical program."

Jan 1, 2014

By R. C. Snider

The Roy Lloyd Mine in northern Saskatchewan is a high-grade underground gold mine which is currently supplying ore to Golden Band Resources Inc. (Golden Band)?s Jolu mill. Prior to the operation of the mine, an underground exploration program was conducted intermittently at the site. During both the underground exploration phase and mining, Golden Band has implemented water recycling to reduce freshwater usage within the mine in order to address concerns over the potential for impacts associated with freshwater usage and to reduce the volume of effluent discharged from the site. Golden Band initiated an underground exploration program at the Roy Lloyd Mine site (formerly called the Bingo Project) in October 2007 to better delineate the mineralization of the Bingo gold deposit. The exploration program provided geological information required in order to improve the confidence level of the geological resource model and also provided information to aid in the mining of the deposit, such as the determination of groundwater inflow rates. Underground production mining started in March 2011. This paper provides an overview of the mine water recycling methods implemented at the site during both the exploration and initial mining phases of the project, and the success/drawbacks of these measures to date, including the potential cost savings in the form of reduced treatment and monitoring costs inherent in a reduction of the volume of effluent discharged from the site. The paper will also discuss options that are currently being evaluated in order to further assist Golden Band?s ability to recycle water and reduce the volume of effluent discharged to the environment, while ensuring effluent discharged from the site to the environment meets criteria.

Nov 1, 2011

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 Asfahani. Jamal, Randa Mohamad

"Abstract - Electrical and structural characteristics of formations favorable for sulfur occurrences in northeast Syria are described using geo-electrical prospecting methods. Simple (VES) and combined (CVES) Schlumberger vertical electrical soundings and geo-electrical profiling using a Wenner configuration were applied to the Teshreen structure. Six profiles (A, B, C, D, E, and F) at the borders of anticlines, where positive and negative structures are joined and salt formations have a tendency to disappear, were studied.Secondary structures, characterized by high apparent resistivity exceeding 3000 Ohm.m were located on each profile using a Wenner profiling configuration. These secondary structures are demonstrated to be favorable for sulfur prospecting by both drilled wells and vertical electrical soundings. Traditional interpretation of the 84 VES measurments is supported by data from 14 CVES measurments. The CVES technique is a powerful tool, due to its improved resolution of the electrical boundaries.Thicknesses and resistivities of the Lower Al-Fares, Al-Garibeh, and Al-Dibbaneh formations were determined through the interpretation of VES measurments. The same VES measurments were then interpreted using the Pichgin method, whereby all the subsurface tectonic features were determined for depth penetration corresponding to AB/2 = 1000 m. The integration of the first and second VES phases creates a clear picture of the subsurface, including tectonic, geometric, and geoelectrical information. In summary, the sulfur occurrences in the research area are controlled by tectonic paths that are well defined by geo-electrical methods. These diverse geo-electrical methods could be used successfully for sulfur prospecting in similar environments."

Jan 1, 2002

By Kimberly M. Curran

The path by which hydrogen supply is provided to any end use application will have a strong effect on the specific economics and price stability for the product supply and the flexibility with which it can be used. The objective of this paper is to present those variables which play a significant role in the selection of the hydrogen production technology, with a particular focus on several typical mining applications. The variables examined include gas requirements in terms of flow-rate and demand profile, overall volumetric consumption, level of interruption tolerable, gas pressure and quality needs. Also examined are the effects of geography in terms of primary energy supply available as well as existing hydrogen sources, developed or not. The role of these factors in the selection of an appropriate supply chain capable of supporting mining applications that use hydrogen as an energy carrier will be illustrated with a typical mining application scenario drawn upon in the form of a case study.

May 1, 2007

By K. Ski

Three series of membranes were prepared by blending polyvinylidene difluoride (PVDF) or poly(vinylidene difluoride-co-hexafluoropropylene) [P(VDF/HFP)] with sulfonated poly(ether ether ketone) (S-PEEK), sulfonated polysulfone (SPU), or sulfonated polystyrene, in order to develop novel PEM membranes suitable for melt processing. By means of incorporating fluorine-containing block copolymer into the blended system, acceptable proton conductivity and low water containing PEM materials were prepared. The effect of sulfonated poly([vinylidene difluoride-co¬hexafluoropropylene]-b-styrene) block copolymers as compatiblizers was investigated: conductivity was enhanced for S-PEEK/fluoropolymer blends. Microstructures for the blends were examined by transmission electron microscope (TEM) and scanning electron microscope (SEM).

Jan 1, 2005

By T. Navessin

Recent research activities in proton exchange membrane fuel cell (PEMFC) have significantly improved the performance per unit cost and its lifetime. These activities narrow the technology gaps, and thus, enable commercialization in some applications. One particular focus is in the development and understanding of proton conducting membrane materials. Many novel membranes are being developed which provide control and systematic understanding of complex relationships between chemical structure, morphology, physicochemical properties, and electrochemical kinetics. In this study, different classes of proton conducting membranes suitable for portable and automotive applications were evaluated in an operating PEMFC at the Institute for Fuel Cell Innovation, National Research Council. Analysis of these results may provide constructive feedbacks to the material researchers.

Jan 1, 2005

By P. W. A. Walker

"The Riviera tungsten occurrence in the Cape Province of South Africa was discovered in October 1979 as a result of stream-sediment panned concentrate sampling. The Cape age granite and late Precambrian Malmesbury Group carbonates and chlorite schists which it intrudes and which host the mineralization are covered by between 10 m and 30 m of Tertiary/Recent alluvium and clay. The scheelite/powellite and molybdenite mineralization occurs in a greisenized granite cupola with an overprint of porphyry-type alteration as well as in minor skarns. The ore reserve is estimated to be 46 million tonnes at an average grade of 0.216% W03 and 0.020070 Mo. The deposit is uneconomic at current tungsten prices. IntroductionDuring the 19705, Union Carbide Corporation was a major producer, processor and supplier of tungsten and derivative products to end-user manufacturing industries. The corporation owned and operated two tungsten mines in the United States, and one in Brazil, and operated a plant in the United States which produced ammonium paratungstate (APT) which is an intermediate product in the production of tungsten wire and tungsten carbide for cutting tool insets and hard facings. In 1975 the three mines were ageing with short-life reserves and high production costs. The world market for tungsten was buoyant and prices, in constant dollar terms, had risen steadily over the past 15 years (Fig. 1).It was against this background that a decision was made to explore for tungsten in North America, South Mrica, Australia and Brazil."

Jan 1, 1994

By Alan L. Sangster

Auriferous, bedding-parallel veins occur in zones of carbonaceous, argillaceous and sulfidic turbidites in the Lower to Middle Cambrian sandy flysch of the Goldenville Formation. The 0348 values for vein and wall-rock arsenopyrite and pyrrhotite, and for regional pyrite and pyrrhotite, are highly positive. The values are similar to those from Cambro-Ordovician sediment-hosted deposits of other types, and display trends that increase upward in the stratigraphic sequence. The similarity in composition of vein and wallrock sulfides indicates a seawater-sulfate sourCe for sulfur, derived from the enclosing rocks at the time of vein formation. The upward increase in ?34S values is consistent with closed system sulfate reduction in the anoxic portion of a stratified water-colurnn. Published ? 13C and ? 18() values for Meguma Group vein carbonates are unlike those of other gold-vein carbonates, but are similar to those of diagenetic-metamorphic carbonates from the Meguma Group and elsewhere. These data indicate that the source for the vein-related sulfides and carbonates may be the host strata; possibly the arsenic and gold were derived from the same source.

Jan 1, 1992

By Y. A. Grinin, M. A. Liamina, V. A. Shumskij, Y. I. Sannikov, M. V. Radashin

"A brief history of the development of the Kivcet flash smelting process is presented. The broad scope of the process with an ability to treat high grade lead sulphide concentrates, as well as oxidized lead-zinc residues, is emphasized. Fine coal in the charge serves two purposes, one as auxiliary fuel and the other as a pre-reductant for ferric iron in residues. Current Kivcet operations incorporate a layer of coke or “coke checker” at the surface of the slag in the reaction shaft that acts as a reducing agent for flame products or slag that flow through it. Details of this invention, are given. IntroductionFor many years, the sinter-blast furnace lead smelting process has been the main internationally accepted method used for the production of primary lead metal. In recent times, this process has been unable to meet legislated environmental restrictions and it became clear in the mid-1960s that a new and cleaner process would have to be developed. The present level of Kivcet performance was developed in three main stages:1. flash smelting natural sulphide lead raw materials with the attached electric furnace for production of lead bullion and crude zinc;2. natural raw material smelting with lead and zinc separation in a “coke filter” or “coke checker” at the surface of the slag in the reaction shaft to produce lead bullion and ZnO-bearing slag that can be fed to conventional slag fuming; and3. processing of oxidized lead-bearing raw materials, such as low grade zinc plant residues, with the production of lead bullion and ZnO-bearing slag periodically directed to slag fuming."

Jan 1, 1998

By Xuehui Xia

Abstract -There are a number of sedimentary exhalative massive sulfide (SEDEX) deposits in the Proterozoic Langshan-Zhaertai rift at the western segment of the northern margin of the North China platform in China, including more than ten large, medium and small deposits located in a belt of 300 km EW by 50 km to 100 km NS, with large Cu, Pb, Zn, Ag, and S reserves. In several representative SEDEX deposits in the rift, the mineralizing elements are prominently zoned, horizontally or vertically, with Cu decreasing but Pb increasing from west to east, Cu decreasing but Zn increasing from bottom to top, and Zn restricted to the bottom half. The ore-hosting rocks, characterized by a clear manganese halo, have developed a polymetallic mineralization in positive relation with their carbon contents. Their isotopic aspects are: ?34S has relatively large positive values, fluctuating between +5‰ and +35‰, compared with Pb isotopic compositions which are less variable, with a model age of 1600 Ma to 1800 Ma, showing that they are mantle-derived. The mineralizing materials were associated undoubtedly with the contemporaneously faulting events in the rift. The deposits owe their origin to seafloor exhalation, with sedimentary rocks as their hosts.

Jan 1, 1999

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 Marcel M. Djivre

The paper will outline the methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. Also for Canadian mines the paper will suggest proposed criteria to be used at MTL for the evaluation of ropes used in "ultra-deep" single-lift shafts. Most of the methods and test procedures currently used at MTL were adopted during the revision of the CSA Standard G4, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage to be published most likely in year 2001. In this latest or sixth edition of CSA Standard G4, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The existing fifth edition of CSA Standard CAN/CSA -G4-92, which is intended for the manufacturing of new ropes, includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish.

May 1, 2001

By Joe Price

Canada?s energy future will increasingly depend on a supply of light, sweet crude oil derived from the Athabasca oil sands deposit of North-eastern Alberta. Billions of dollars are being spent on the construction of new and expanded mine and bitumen extraction plants, in situ recovery facilities, pipelines, upgrading installations and all the infrastructure needed to support these projects. The success of the existing operators has also inspired new players, anxious for ?a piece of the action? to come forward with exciting project proposals of their own. None of this investment and spin-off economic activity would be taking place today if events had unfolded differently in this part of the world some one hundred million years ago. The accumulation of sand in rivers, estuaries and in the near-shore marine environment created the great reservoirs that host the enormous oil deposits these projects are designed to exploit. Mine operators of all stripes will likely agree that there are few good ?geological surprises?. With specific reference to oil sand deposits, the geological history determines the distribution of sand, silt and clay bodies, which in turn controls the ore grade. Important design factors including everything from stable pit slope angles to tailings properties reflects events that took place millions of years before. An understanding of the sequence of events that resulted in deposition and preservation of the sediment and oil are important to sound design for both mining and in situ facilities. A geological history of the region is described. Site-specific examples from Syncrude?s operating mines are used to illustrate some of the geological factors that can present design challenges.

May 1, 2003

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