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By Leslie McHattie

?Intelligent mine? conjures up a futuristic image of unmanned extractors and loaders working in harsh conditions in a remote lunar landscape. The promise of increasing mine fleet productivity and solving the problem labor shortages in mining regions can certainly be achieved today through remote controlled extraction and automated hauling. The technology is available and it doesn?t seem to be so much science fiction when Google?s self-driving cars hurtle down the freeway. ?Intelligent mining,? on the other hand, implies the application of information technology at every phase of the mining value chain, from exploration and geological modeling to equipment, operations and maintenance, and logistics and transportation. These are really industry-specific, enterprise-class software solutions focused on using information technology to support the business processes of mining and make them more efficient and effective. Overlaying the physical world with the digital or virtual world enables us to model and simulate our assets, giving us the ability to effectively design, build, and ultimately optimize the performance and reliability of our assets throughout the lifecycle. The digital asset, often a 3D model, is created initially during the engineering and construction phase, and is handed over to the operator before the mine goes into operation. Combined with geospatial or geographic information systems, the operator has a complete digital representation of the physical world, which forms the foundation for risk and performance management, along with compliance and regulatory reporting. Laser scanning and positioning technology can be used to create point clouds ? information models consisting of millions of data points ? which enable the visualization and representation of the ?as-operated? reality. But consider that once the mine is in operation, it throws off an endless stream of data in the form of performance and condition data from sensors and monitoring devices on fixed and mobile assets through networks, servers, and services. This ?big data? can be processed and analyzed to spot trends, help predict events, and formulate reliability strategies as early as the design stage (e.g., reliability-centered design). ?Intelligent mining? implies that massive amounts of data augment the reality of the physical mine, plant, and equipment. This embedded intelligence can be used to optimize operational efficiency, increase asset availability and utilization, improve safety and environmental integrity, and maximize return on investment. Lastly, the sweet spot for intelligent mining is seen in the convergence of consumerization and industrialization. The application of ?consumer? technologies that we use every day on our iPhones and Android devices, such as cameras, motion sensors, and positioning in an industrial context, are producing ?immersive? experiences. Overlaying the digital world on the physical world and connecting them accurately through intelligent positioning results in ?intelligent infrastructure,? which is safer and more sustainable. Bentley Systems works with many mining companies and engineering, procurement and construction companies involved in all aspects of mining infrastructure development. In fact, 10 of the top 20 mining companies ranked by market capitalization are users of Bentley software, including all of the top five. In addition, Bentley provides software solutions to the world?s leading engineering, procurement, and construction companies, as well as owner-operators, who design, build and operate the world?s infrastructure. Bentley?s solutions for mining and resource extraction industries help increase the efficiency of capital projects associated with the design, procurement, and construction of mines and processing plants, as well as the operation and maintenance of mining fleet and equipment.

Aug 1, 2013

"The outlook for Eastern Canada is decreasing coal production over the next few years; however, a reappraisal of the long-term requirements and increased prices of coal could lead to a revitalizing of the industry. The market for Western coal is expanding and is expected to exceed 50 million tons per year in the metallurgical and thermal power fields. Western coal reserves are currently estimated at 119 billion tons. Technical developments in Eastern Canada include a shearer and gate-end support system to mechanically cut the stall and brushing at the tail-end of a longwall. In Western Canada, the most modern equipment is used in mining, beneficiating and shipping coal. Results to date on the underground hydraulic experiments exceed expectations. The importance of reclamation is recognized and plans have been made to restore and re-vegetate disturbed areas and mine dumps. In Eastern Canada, experiments were started to determine the feasibility of coal reclamation from mine dumps, including one dump that is on fire. The Mining Research Centre, Mines Branch, continued to conduct research work oriented toward solving Canadian mining problems The Western office of the Centre, opened in 1970, was set up primarily to study problems associated with a resurgent coal industry."

Jan 1, 1971

By C. P. Moore, G. W. Taylor

Vertically dipping lenses of nickel-copper ore at Dumbarton Mines Limited are being mined by a modified blasthole stoping method. The principal access to the mine is provided by a 15-degree decline, which, in conjunction with the use of ramps and declines for secondary access, maximizes the accessibility and mobility of trackless mining equipment. Sublevels are driven in ore on 80-foot vertical intervals and subsequently the ore, ranging in thickness from 15 to 30 feet, is slashed to its limits by a procedure of face sampling and test holing. Two longhole drill jumbos are used to drill off 40-foot vertical slices above and below these levels. Following blasting, the ore falls by gravity to the 500-foot horizon, where it is removed from drawpoints by load-haul-dump units and transported by truck to the main orepass. The rock is crushed to minus 3-4 inches and conveyed to surface by a 30-inch-wide wire rope suspended conveyor. This is achieved in two flights, a lower one of 290 feet and a main flight of 2260 feet. All aspects of the mining operation are discussed in the paper, including ventilation, services and safety.

Jan 1, 1973

By J. S. Redpath

There appears to a definite trend toward the hoisting of greater tonnages from greater depths. There is every indication that this trend will continue and we feel that improvements in the design, fabrication and installation of mine guides will be of significant importance in the future. The present state of the art in mine-shaft guide systems is reviewed and the parameters required for improvement are derived in this paper. Finally, a proposal is made for a new steel guide system which meets the parameters and is economical to fabricate and install.

Jan 1, 1977

By A. M. A. Mohamed, F. H. Samuel, S. Valtierra, H. W. Doty, A. M. Samuel

"The influence of Fe, Mn, Cu and Mg alloying additions, Sr modification and grain refinement on the microstructure of as-cast and solution heat-treated Al-10.8% Si alloys was investigated using optical microscopy and EPMA techniques. The results showed that the modification effect of Sr diminished with increasing Cu and Mg additions, due to Sr-Cu-Mg interactions. Strontium caused segregation of AlzCu in areas away from eutectic Si regions, and altered the precipitation sequence of the a-Ah5(Fe,Mn)3Siz iron intermetallic from post-dendritic to pre-dendritic, with the phase observed within the a-Al dendrites. Depending upon the alloy Fe and Mn content, a coarser variation (""sludge"") of the a-Fe phase occurred, in the form of polyhedral shaped particles. The AhCu phase dissolved almost completely during solution heat treatment, while Al5Cu2Mg8Si6, sludge, and a-Aln(Fe,Mn)3Siz phases persisted in all alloys, particularly at high Mg and Fe levels. The f3-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, the dissolution becoming more pronounced after solution heat treatment."

Jan 1, 2006

By Douglas R. Piteau

"Assessing the stability of a slope cut in rock is basically a problem of engineering geology - geology, because it involves a sound understanding of the important aspects of geology, such as geological structure, ground water, weathering and other natural phenomena, which all relate to or exist in a geological environment, and engineering, in that quantitative evaluations and calculations are necessary, these being based on mechanics and relating to the strength of the geological materials and the forces causing instability of the slopes. The engineering geologist must make every attempt to. provide, in a quantitative way, information on those geological factors which are necessary for making calculations of the probable stability of the slope. These include numerical assessments of quantities relating to the characteristics of structural discontinuities, rock types, topography, hydrogeology, tectonic history and other environmental factors. Based on the development and extension of these general principles, both preliminary and final slope stability studies of some open pits in South Africa, Swaziland and Zambia have been conducted. Some of the basic concepts and techniques developed to carry these studies out are described."

Jan 1, 1972

By R. Loney, M. Militzer

There is a significant demand for new high strength steels with fine grain sizes for structural applications. One approach in this regard is to develop hot-rolled HSLA steels where refining the microstructure leads to increased strength levels, e.g. 700 MPa yield strength, that can be attained by suitable modifications of chemistry and processing. Here, an HSLA steel is investigated that contains 0.05wt%C-1.65wt%Mn-0.20wt%Mo¬0.07wt%Nb-0.02wt%Ti and approaches the above strength class. The ability to control and predict the mechanical properties of hot rolled steel depends strongly on the thermomechanical processes, which the steel undergoes. The final microstructure and, thus, the properties of the hot-rolled steel are a function of the austenite decomposition obtained during accelerated cooling on the run-out table and precipitation during coiling. The austenite-to-ferrite phase transformation under run-out table conditions has been investigated using a Gleeble 3500 thermomechanical simulator equipped with a dilatometer. The effects of cooling rate and initial austenite microstructure including the degree of work hardening on austenite decomposition kinetics and ferrite grain refinement have been quantified. Results show that grain refinement can be optimized by the presence of work hardened austenite and accelerated cooling. Based on the experimental results, a model is proposed to predict the transformation start temperature and the resulting ferrite grain size for run-out table cooling conditions.

Jan 1, 2004

By Greg Barnes

Agenda ? The Mining Stock Life Cycle ? Current Environment ? Valuation ? Golds ? Valuation ? Base Metals ? Case Study ? Quebrada Blanca Hypogene Commodity Investment Cycle ? Macro-Economic Indicators ? LME Inventories ? watch the trend; rising inventories ? bad for prices, declining inventories good for prices ? OECD Leading Indicators ? PMIs ? Purchasing Manager Indices ? Industrial Production ? more important for metals consumption than GDP ? Housing Starts ? US, Europe ? Auto Sales ? All things China ? metal imports/exports; SHFE inventories; SRB stockpiling ? Seasonality ? it does play a role ? What is Chris Dutton (TDSI Quantitative Analyst) saying?

May 1, 2010

By Victor R. Eyzaguirre

Cerro Verde is one of several large porphyry-type copper deposits in Southern Peru. The copper occurs as primary sulphides, with a significant oxide capping. The exploitation of the deposit has been correspondingly divided into two stages, the first consisting of copper production from oxides, and the second from sulphides. Minero Peru successfully started the Stage I plant in June of 1977 with the first production of electrowon copper cathodes. This paper is essentially devoted to a description of the Stage I process, which can be summarized as follows: Ore is trucked to the primary crusher, where it is crushed to 225 mm and conveyed to a coarse ore stockpile. Ore withdrawn from the stockpile is secondary crushed to 65 mm, conveyed to a truck loadout bin, loaded into trucks and driven to the leaching pads. Ore is placed on the pads in lifts and sprayed with sulphuric acid solution to dissolve the copper. Copper-bearing solution forms a pond behind a dam at the lower end of each pad and is pumped from there to the solvent extraction plant. Copper is extracted from the leach solution into an organic phase and is then stripped from the organic phase to form a purified concentrated copper solution suitable for feed to electrowinning. In electrowinning, the copper is finally recovered as cathodes suitable for sale as refined copper.

Jan 1, 1978

By H. Hamza

Efficient and effective management of extraction process tailings is an essential ingredient for the continued success and development of Alberta's vast oil sands resources. Open-pit oil sands operations north of Fort McMurray recover bitumen from flotation circuits. Process tailings are managed in carefully engineered and monitored external tailings management facilities and in below-grade mine pits. In order to support reduction of production costs and improve upon established tailings management practices, CANMET has been working with the oil sands industry in a collaborative framework to assess the potential to integrate thickened tailings into oil sands extraction process flowsheets. Albian Sands has commercialized the process while others, including Syncrude Canada Ltd., continue to evaluate the suitability of the process for their operations. This paper provides an update on R&D work undertaken in recent years to assess and develop the potential of thickened tailings technology for the open-pit oil sands operators of northern Alberta. The aim of this work was to explore opportunities to optimize process efficiency and environmental sustainability by improving water and energy conservation and develop more alternatives for tailings management and reclamation.

Jan 1, 2004

By Bird. M.

As the Cadia mill was the first 40ft diameter SAG mill, commissioned in 1998, its performance, liner and discharge design attracted considerable international attention. Twelve years on, the liner design and the control philosophy are being readdressed to further improve the mill?s performance. A comprehensive series of 3D liner scans, over life of the liner, have been used to calibrate liner mass loss and progressive changes in the liner profile. This data is being used to provide true charge mass and mill filling, plus progressive trajectory profiles over life of liner. This information, along with measures of mill performance over liner life, is being used to select the optimal operating conditions as the liner wears, and hopes to inform future liner design.

Jan 1, 2012

By CIM Mineral Resource, Mineral Reserve Committee

The CIM Mineral Exploration Best Practice Guidelines (the Exploration Guidelines) have been prepared to assist professional geoscientists and engineers to conduct consistently high-quality work in order to maintain public confidence. The Exploration Guidelines are meant to assist professional geoscientists and exploration practitioners in planning, supervising, and executing exploration programs. In Canada, there are generally two types of public resource reporting: “Disclosure”, as defined by NI 43-101, is the reporting of technical information to the public and market participants for securities legislation purposes where a Qualified Person (QP) must be involved, and reporting of exploration information for governmental agencies to support obligations under laws including the Mining Acts of each of the Provinces and Territories. The Exploration Guidelines are also relevant where the results will not be publicly reported but are intended for internal company use. While this document is intended as guidance for work conducted or supervised by geoscientists in Canada, many of the practices described herein can be adapted to mineral exploration activities in other countries. The Exploration Guidelines are not intended to inhibit original thinking, or to prevent the application of new approaches that may develop into fundamental components of successful mineral exploration programs. Rather than provide prescriptive solutions to specific issues, they include general guidelines for current professional practice and to demonstrate and defend the merits of new methods. These guidelines do not preclude individuals and companies from developing more detailed guidelines specific to their own requirements. The initial version of the Exploration Guidelines was prepared by the Canadian Institute of Mining and Metallurgy and Petroleum (CIM) Exploration Best Practices Committee and adopted by CIM Council on August 20, 2000. On January 9, 2018, CIM Council formed a new committee, the Mineral Resources and Reserves Committee (CIM MRMR Committee) with a mandate to, among other things, update the Exploration Best Practice Guidelines. The mandate for the committee was accepted by CIM Council on March 2, 2018. The new document was adopted by the CIM Council on November 23, 2018.

Nov 23, 2018

By T. L. McCall

AUTHENTIC records show that coal mining in Cape Breton dates from the year 1720, when the French military authorities obtained coal from what is now known as the Blockhouse seam, in the Morien district, for use at Louisburg, where the fortress, now of such historic interest, was being built. Thereafter, coal was mined more or less continuously, and although, for many years, in a very haphazard way, there was, on the whole, a steady growth towards a better regulation of the industry, culminating in the year 1825 with the arrival of the General Mining Association in Nova Scotia. This Company, more generally known as the G.M.A., had acquired extensive tracts in Brazil and Colombia and had also purchased the mining rights for the whole of Nova Scotia-excepting such areas as had been previously leased-the attraction being the rich veins of copper currently reported as occurring in the Province. These fabulous copper veins, upon examination, failed to materialize, but the engineer sent out to report on them returned with such good accounts of the coalfields he had seen that steps were taken immediately to investigate them. From that rime onward, the history of coal mining in Nova Scotia is one of progress and achievement. One of the first acts of the G.M.A. was to acquire the areas already leased to other concerns and develop these in a masterly fashion, employing the best machinery and talent available at that time. Such dominant control over the minerals of the Province, although it led to orderly development in the several coalfields, also, later on, resulted in restricting operations in the various coal centres to such an extent that a determined effort was put forward by the people of Nova Scotia to end such a state of affairs. Consequently, in 1857, the original lease of the G.M.A. was abrogated, the Company, however, being allowed to retain certain areas in the districts it had already developed. This opened the way for the formation of other coal-mining companies, and numbers of these immediately sprang into existence in the various coal-mining centres. In 1893, the Dominion Coal Company, Limited, was formed by the amalgamation of seven companies operating in the neighbourhood of Glace Bay, in Cape Breton. Later, in 1910, the Dominion Iron & Steel Company, Limited, obtained control of the Cumberland Railway & Coal Company, which had been formed in 1884 to acquire the rights of the two companies working in the Cumberland County coalfield.

Jan 1, 1936

By M. Pearson, J. Irvine, L. Mercer, P. Lauzon

Severe service ball valve performance has a direct impact on the mechanical availability of high pressure oxidation and leach plants. The primary function of these valves is to isolate the autoclave for maintenance. Valve failure has historically contributed significantly to the maintenance downtime of these process plants. An understanding of the root causes of valve failures is the first step in increasing the reliability of the severe service ball valves. A rigorous failure analysis practice has been developed by Hatch for investigating refractory failures in furnaces and kilns based on Kepner-Tregoe methodology. The method has also been modified for valve failure analysis. From a root-cause failure tree analysis of each of the valve components, a list of all potential valve failure mechanisms was developed for ranking and evaluation, along with recommendations for further valve development. The purpose of this paper is to present the reader with the modified Kepner-Tregoe method and examples of this analysis.

Jan 1, 2004

By M. Y. Levesque

The Australian Government?s Energy Efficiency Opportunities (EEO) program launched in 2006 obliges companies that use more than 0.5 PJ (petajoule) or roughly 139 GWh (gigawatt hour) per year to conduct an energy assessment in order to identify measures to improve energy efficiency. The opportunities identified by the mining sector were assembled in the Mining Significant Opportunities Register that permitted companies not yet embracing and adopting an energy management program to see what those who are, were doing and how much energy was saved, and helps disseminate best practice. The measures can be filtered by company, year, category or equipment type. The creation of a central repository of energy efficiency initiatives is valuable but this existing database could be improved; fields identifying the energy and carbon emission savings associated with a given initiative are a surprising omission. Consequently it does not permit the relative effectiveness of different measures for energy and carbon reductions to be readily assessed. A review of energy management efforts implemented in the mining industry, published in peer reviewed journals, corporate sustainability reports or industry publications during the last 40 years has revealed many examples of best practice. However, the lack of a standardized reporting framework in any of these sources has made it difficult to assess the effectiveness and compare the adopted energy management measures ? just as is the case with the Australian register. In an attempt to address these issues, an improved database structure has been created for energy management measures from the mining industry which identifies energy and financial savings arising from energy management initiatives, classifies applications to specific processes or equipment, and recognizes leaders in the mining industry with respect to energy management. The structure of the register includes the key data relevant to energy management in mining that is absent in the Australian version. The mining industry energy management database has been made available in the public domain where stakeholders can examine the best practice examples. Mining energy champions may also contribute to the register by providing case studies; a standardized entry template affords a quality assurance dimension that is absent in other reporting initiatives. Adoption of this database with its standardized reporting mechanism will enhance transparency of the mining industry in energy matters and help it maintain its social license to operate.

Aug 1, 2013

By Edwin G. Sharp, Frank S. Gaunce, George M. Freeman, Denis J. Kemp, Eric Dulson, Paul Salmon, Ernest R. Hamilton, Carl E. Parden

"THE ECSTALL ZINC PLANT was built for the treatment of the Kidd Creek zinc sulphide concentrates. Construction proceeded throughout 1970-71, with operations beginning in April 1972. The two concentrate types treated differ principally in minor impurity and precious metal contents. Processing flexibility was required to allow efficient recovery of the by-products, especially cadmium, copper and silver. The conversion of the zinc sulphide concentrates to end products follows a sequence of operations that are common to most electrolytic zinc plants and typical of the ""Tainton- Jephson"" flowsheet.1. Roasting in air at an elevated temperature to convert the metal sulphides to soluble metal oxides (calcine) and sulphur dioxide. The sulphur dioxide is converted to sulphuric acid in a contad plant and shipped by train to market.2. Leaching of the calcine in spent electrolyte to effect extraction and recovery of zinc as zinc sulphate solution, leaving an insoluble residue.3. Purification of the clarified zinc sulphate solution by cementation with metallic zinc dust to remove impurities detrimental to the electro-deposition of zinc or detrimental to product purity. The solids from cementation are the starting materials for secondary metal recovery.4. Electrolysis of the purified zinc sulphate solution to reduce the zinc to the metallic state while coincidentally regenerating the sulphuric acid for recycle to the leaching step."

Jan 1, 1974

By B. Haugrud, E. McConaghy, M. Collins, G. Smith

"Laterite ore processed by the Ambatovy joint venture in Madagascar is primarily limonitic in nature, containing approximately 40–45 wt.% Fe and 1.1 wt.% Ni. The process selected for treatment of this ore considered the behaviour and deportment of iron in each step of the commercial flowsheet. Such considerations included nickel and cobalt recoveries, reagent consumptions, liquid-solid separation characteristics, and intermediate and final product purities. In this paper, the results for the first three years of commercial operation at Ambatovy are compared with the design parameters, with emphasis on the behaviour of iron.RÉSUMÉ Le minerai latéritique traité par l’entreprise commune Ambatovy au Madagascar contient principalement de la limonite, composée de 40–45 % en poids (wt%) de fer (Fe) et de 1,1 wt% de nickel (Ni). Le procédé choisi pour le traitement de ce minerai tenait compte du comportement et du maintien du fer à chaque étape du schéma de traitement commercial. Parmi les facteurs pris en compte figuraient les récupérations de nickel et de cobalt, les consommations d’agents réactifs, les caractéristiques de séparation des liquides-solides ainsi que la pureté des produits semi-fini et final. Cet article compare les résultats des trois premières années d’exploitation commerciale à Ambatovy aux paramètres d’étude, en insistant notamment sur le comportement du fer.INTRODUCTIONThe main component of nickeliferous laterite ore is iron, and the Ambatovy deposit in Madagascar is no exception. Ambatovy ore is primarily limonitic in nature, containing approximately 40–45 wt.% Fe and 1.1 wt.% Ni. The nickel content of the ore is approximately 1/40th that of the iron content by weight; therefore, successful recovery of nickel depends on close control of the behaviour of iron in the selected process.The Ambatovy area is located 80 km east of Antananarivo, the capital of Madagascar. Exploration dates back to 1960, when the Malagasy Service Géologique carried out a limited pitting and auger-drilling program. Phelps Dodge Corporation (now Freeport-McMoRan Copper & Gold, Inc.) was granted the mining rights to the property in 1995 and carried out significant resource definition, environmental assessment, and engineering studies between 1995 and 2001 (Chou, Rooke, Williams, & Hanks, 2000). In 2003, Dynatec Corporation, which was formed in 1997 by the merger of Dynatec International Ltd. and Sherritt International Consultants Inc., signed a joint venture agreement with subsidiaries of Phelps Dodge to evaluate the Ambatovy nickel project. Dynatec became extensively involved in the development of the project, including process selection and pilot plant testing in Fort Saskatchewan, Alberta (Collins et al., 2004, 2005; Collins & Vardill, 2005; Collins, Buban, Holloway, Masters, & Raudsepp, 2009). Dynatec acquired 100% of the project in 2005 and a joint venture between Dynatec, Sumitomo Corporation, Korea Resources Corporation (KORES), and SNC-Lavalin Inc. (SLI) was formed shortly thereafter to provide funding for further development. SLI was responsible for engineering, procurement, and construction management of the commercial facilities. Sherritt International Corporation reacquired Dynatec Corporation, including 40% ownership in the Ambatovy nickel project, in 2007. The current Ambatovy joint venture consists of an integrated nickel and cobalt mining, processing, refining, and marketing enterprise between subsidiaries of Sherritt (40% owner and mine and plant operator), Sumitomo Corporation (32.5% owner), and KORES (27.5% owner)."

Jan 1, 2017

By J S. Kermeen

This paper deals with drilling and blasting techniques at the Phoenix mine, near Grand F1nks, B.C., which is now operated by The Granby Mining Company Ltd. The difficulties of open-pit mining through former underground workings are unique to this operation. Rock types are related to drilling conditions, and the methods used, or contemplated, to overcome the several difficulties are outlined. The equipment used is also mentioned. Finally, blasting techniques and costs are reviewed. Introduction T HE Granby Mining Company operates on open-pit copper mine and concentrator at the site of the original Phoenix mine, near Grand Forks in south-central British Columbia. The pit is a side-hill cut measuring approximately 1,000 by 2,000 ft., and covering a vertical range of from 4,550 to 4,950 feet above sea level. The mill is currently operating at 1,900 tons per day. A 4.5 to 1.0 waste to ore ratio necessitates the removal of some 15,000 tons of ore and waste per working day. Mining conditions at Phoenix are extraordinary in that all the ore zones currently being

Jan 1, 1965

By The Staff

"THE Wabana iron ore mines, owned and operated by the Dominion Steel and Coal Corporation, Limited, .are on Bell Island in Conception bay, on the east coast of Newfoundland. Mining began on surface in 1895 and, although open-pit work is still done on a small scale, the entire output may be considered to•be derived from extensive submarine workings. In 1958 the average daily production of hematite ore was close to 12,000 tons, almost all of which was concentrated in a heavy-media plant. SUMMARYThe character, occurrence, and extent of the submarine bedded deposits enabled early operators to meet prevailing market demands with the minimum attention paid to exploration. Mechanization of the mine and the pressure for sustained high tonnages since 1955 have emphasized the importance of an expanded exploration and development programme.A serious handicap has been the impossibility of utilizing normal diamond drilling methods to explore ore conditions in advance of mining faces. Drilling between tl1e bedded zones has been done but the major difficulty has been to delineate ore reserves in the lower bed, which has the greatest ore potential of the three mineable seams."

Jan 1, 1960

By R. Lasmanis, W. C. Utterback

"The Mount Tolman porphyry Mo-Cu deposit is 64 km south of Republic, Ferry County, Washington. It occurs in the composite Keller Butte pluton, which consists of the Keller Butte porphyritic biotite granite and granodiorite, the Mount Tolman quartz porphyry granite, and the Meadow Creek biotite granite phases. The three phases range in age from 61.3 Ma ± 2.3 Ma to 55.7 Ma ±2.0 Ma. The stockwork deposit occurs in the Keller Butte phase above the contact with the Mount Tolman quartz porphyry granite.Mount Tolman is a hybrid calc-alkaline deposit that has features of both a Climax-type and a plutonic type. Prior to post-ore faulting, the deposit had a flattened hood like shape. In plan it is elongated- 1.6 km wide, 3.2 km long, and up to 609 m thick. The orebody has a 292 o strike. It contains a geologic reserve exceeding 2.18 billion tonnes of ore averaging 0.093% MoS2 and 0.09o/o Cu using a 0.048% MoS2 cutoff. Of this total, 816 million tonnes of measured and indicated ore averaging 0.097% MoS2 and 0.09o/o Cu could be mined by open pit with an overall waste-to-ore ratio of 0.91 to 1.The deposit is a stockwork of quartz and quartz-sericite-pyrite veins and fracture fillings that contain molybdenite, chalcopyrite, sphalerite, and magnetite. Five separate episodes of fracturing and mineralization produced the orebody and were followed by four additional episodes of fracturing with sulrgrade mineralization. The Mount Tolman deposit contains propylitic, argillic, phyllic, topaz greisen, and potassic alteration zones. Extensive silicification overlaps the K-feldspathized, quartz-topaz, and phyllic alteration zones."

Jan 1, 1995