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By Robert C. Merritt

Laboratory amenability studies as well as a pilot heap-leaching investigation of low-grade sandstone uranium ores from Wyoming, New Mexico, and Colorado are described. Sulfuric acid heap leaching with oxidation, for 120 days, extracted up to 98 percent, 90 percent, and 79 percent U308 from Wyoming, New Mexico, and Colorado ores, respectively.

Jan 1, 1976

By Robert Thurner

The underground car park "Admonterhof in the historical centre of Graz is an example for the technical and economical success of a complicated structural design using a concept on the basis of the observational method. The intention to built a 20 m deep excavation beneath a protected monument was accompanied by some essential issues: the preservation of the existing state avoiding extensive displacements by means of a girder grid of reinforced concrete, its support on large bored piles and small steel-tube piles with possible active compensation of differential settlements, the excavation support in none built-up areas with secant bored piles, the underpinning of existing buildings with different structures by means of jet grouting. Furthermore the hydraulic gradient and the permeability of a rock formation in a part of the excavation had to be explored with the purpose to control the inflow of groundwater with a level difference of more than 10 m.

Jan 1, 2006

By Dennis J. Callaghan

This report is the result of information obtained from a review of related literature, personal inquiry and on-site examination of active surface coal mining operations. Four improved surface coal mine systems are described in detail and evaluated for feasibility, implementation requirements, environmental benefit and costs. Engineering feasibility emphasizes equipment availability, compliance to design requirements, practicality and industry rating. Implementation potential emphasizes immediacy, ease, acceptability and constraints. Special attention was given to environmental responsiveness, both with regard to the solutions to mined-land reclamation problems and to the concurrency of reclamation. Each system description includes a hypothetical model mine with a depreciation schedule, capital summary, estimated annual production costs, sales price computation, production and operating cost summary, and a sensitivity analysis of mine price to stripping ratio. A program plan and time schedule for demonstrating a selected mining system covers site selection criteria, mine data collection, criteria for controlling and budgeting costs and reporting findings. Ten additional mining methods and techniques are briefly described and evaluated. Common reclamation problems are listed and described. Sixteen state reclamation laws and regulations are abstracted. Sixty-nine references are listed in the bibliography.

Jan 1, 1976

By R. S. Dean

As set forth in the decision of the Trail Smelter Arbitral Tribunal, dated April 16, 1938 This Tribunal is constituted under and its powers are derived from and limited by the convention between the United States of America and the Dominion of Canada signed at Ottawa, April 15, 1935, duly ratified by the two parties and ratification exchanged at Ottawa, August 3, 1935 (hereinafter termed "the Convention") . . . The duty imposed upon the Tribunal by the Convention was to "finally decide" the following questions: (1) Whether damage caused by the Trail Smelter in the State of Washington has occurred since the first day of January 1932, and, if so, what indemnity should be paid therefor? (2) In the event of the answer to the first part of the preceding Question being in the affirmative, whether the Trail Smelter should be required to refrain from causing damage in the State of Washington in the future and, if so, to what extent? (3) In the light of the answer to the preceding Question, what measures or regime, if any, should be adopted or maintained by the Trail Smelter? (4) What indemnity or compensation, if any, should be paid on account of any decision or decisions rendered by the Tribunal pursuant to the next two preceding Questions? In this decision reported to the Government of the United States of America and to the Government of the Dominion of Canada, the Tribunal answered the first question in its entirety and reserved decision on the other three questions in accordance with the following extract from their decision

Jan 1, 1944

By Louis W. Cope

Many Americans have seen Greenland while flying over it on their way to or from Europe. Few have visited this largest island in the world. Portions of the 20 percent of the territory that are not ice-covered are highly mineralized. Greenland could become very productive if the present interest in exploration increases. The people and Greenland’s history The population of Greenland is 57,000. Twenty percent are Europeans, mainly of Danish decent, while 80percent are native Greenlandic or mixed Greenlandic-European. The native population is the same as the Inuit of the Canadian Arctic. They speak the same language.

Jan 1, 2004

By D. Robert Weir, M. J. H. Ruscoe, R. M. Berezowsky, M. A. Clegg

The metallurgical processing involved in the produc-tion of the new Canadian one dollar coin is reviewed starting with the hydrometallurgical production of pure nickel powder, followed by the powder metallurgy process for the production of nickel strip and coinage blanks, and concluding with the Aureate bronze electroplating and heat treatment procedure. Coinage requirements are then reviewed with regard to economic, public acceptance, and service requirements. Finally the properties of Aureate nickel coinage are presented in the light of the many and varied coinage requirements, and it is concluded that the new Canadian dollar coin exceeds the requirements admirably.

Jan 1, 1990

By CIM Mineral Resource, Mineral Reserve Committee

The CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (MRMR Best Practice Guidelines) were prepared by the Canadian Institute of Mining, Metallurgy and Petroleum's (CIM) Mineral Resources and Mineral Reserves Committee (CIM MRMR Committee) to update an earlier version that was accepted by CIM Council on November 23, 2003 (CIM, 2003). These 2019 MRMR Best Practice Guidelines supersede and replace the November 23, 2003 version of the MRMR Guidelines. These 2019 MRMR Guidelines are not intended to be prescriptive and are not intended to provide detailed and exhaustive instructions for preparation of Mineral Resource and/or Mineral Reserve (MRMR) estimates. Rather, they are intended as general guidance to assist professional geoscientists (or equivalent) and engineers (or equivalent) in preparing high quality estimates of MRMR that incorporate sound geoscientific, engineering, evaluation and design practices. They are based on well-established estimation and mine planning principles and are designed to provide general guidelines of best professional practices employed in the preparation of MRMR estimates. Although the 2019 MRMR Best Practice Guidelines are intended for use by Canadian-based mining/exploration practitioners, many of the concepts and practices presented herein are in general agreement with current industry practices in jurisdictions with membership in the Committee for Mineral Reserves International Reporting Standards (CRIRSCO). For this document, persons preparing MRMR estimates are called Practitioners. Preparation of MRMR estimates should be carried out by Practitioners who either hold the status of Professional Geoscientist (or equivalent) or Professional Engineer (or equivalent), or who prepare the estimates under the supervision of a Professional Geoscientist (or equivalent) or Professional Engineer (or equivalent). For the purposes of this document, all references to reporting describe such necessary reports and related documentation that are created as part of the normal-course work flow of preparing MRMR estimates for internal purposes. For clarity, all public disclosure of MRMR estimates made by, or on behalf of, an issuer and intended to be, or reasonably likely to be, made available to the public in a jurisdiction of Canada must comply with the requirements of National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101), as amended from time to time. At least one Qualified Person (QP) must take responsibility for each part of the estimation process when publicly disclosing the results of MRMR estimates. The intended audience for these 2019 MRMR Best Practice Guidelines includes Practitioners at all levels of skill and experience, government agencies, academic institutions, and the public.

Nov 29, 2019

By S. L. Windes

This report presents a tabulation of the physical and petrographic properties of Over 100 rock types from operating mines or mineral-investigation projects. The physical properties include the following: Apparent specific gravity Apparent porosity Compressive strength Flexural strength, (modulus of, rupture) Impact toughness Abrasive hardness Scleroscope hardness Modulus of elasticity (Young's modulus) Modulus of rigidity Specific damping capacity Longitudinal bar velocity

Jan 1, 1949

I N the introductory chapter to "Man and Metals," T. A. Rickard wrote "Five hundred thousand years ago the first footfalls of man's oncoming echoed down the corridors of time." This phrase has always appealed to me, not only for its resonance but because it seems to place in some perspective man's place in the cosmos. As we go about our daily occupations and as we meet here tonight, we must agree that we have come a long way slowly at first through the ages of change but with a quickening pace that has brought to man's know-ledge and use, within the last hundred years, more ideas, more material advantages, more opportunities and more comforts than were ever imagined or dreamed of in those long corridors of time. Looking back to the dawn of his-tory, a mere five thousand years ago, there is one aspect of the birth and growth of civilization that has particular significance for the miner and the metallurgist.

Jan 1, 1965

By Michael P. Amsden

"THE ECSTALL CONCENTRATOR is situated adjacent to Highway 101 and the Ontario Northland Railroad, 15 miles east of Timmins, Ontario. Ore is delivered to the concentrator by rail from the mine, which is 17 miles northwest of the plant. Power and fuel are obtained from the hydro and natural gas lines which pass close to the plant site. Water is obtained from the Frederickhouse River, 6 miles east of the concentrator. The main concentrator building is a large structure 500 by 640 feet by 90 feet high and contains facilities for fine crushing, crushed ore storage, grinding, flotation, tin recovery, concentrate handling and reagent handling. Located in the same building are the machine shop, warehouse, metallurgical laboratory, pilot plant, men's change room, sample preparation area and an assay laboratory. The general concentrator layout is shown in Figure 47. Originally designed to handle 9,000 tons per day, the concentrator now treats 10,000 tons per day. Two different ore types are processed by selective flotation in three individual circuits to recover copper, lead and zinc concentrates. In 1973, another circuit was added to recover pyrite and tin concentrates from the combined zinc tailings of the three main circuits."

Jan 1, 1974

By Charles Hardy

?POWDER METALLURGY? is the production of semiformed or fully formed metal products by compressing metal powders. It had its beginnings in the fabrication of tungsten and molybdenum bars and wire by compression, sintering, and swaging. Powder metallurgy, although still in its infancy with other metals, has shown remarkable progress in recent years. Production of Metal Powders-The first step in any powder-metallurgy process is the production of metal particles of suitable shape and size. Mechanical processes for producing metal powders, as by crushing, stamping, or grinding, are usually not suitable, as the resulting particles may cause laminations and decreased strength in the finished articles. The principal metal powders now in use on a large scale are produced by electrolysis or by reduction of metal oxides by gases.

Jan 1, 1936

By Renaud Adams, Vladimir Salatic

"The El Mochito Mine located in Honduras, Central America, has produced lead, zinc and silver in concentrates since the 1950s. The paper discusses changes made in both lead and zinc circuits to reduce costs while maintaining production during the recent period of low metal prices.The intent of this paper is to show that sometimes thinking “outside the box” is beneficial for progress. Also, in striving for better metallurgical results we should not forget the basics of flotation. Sometimes the latest trends may not be applicable to the ore we are treating and may not meet the operating cost constraints.A major beneficial impact on El Mochito metallurgy was achieved when the overall grind was coarsened, eliminating the significant percentage of slimes. Switching from two parallel twostage grinding circuits to one circuit with three-stage series grinding has resulted in a significant reduction in power and steel consumption. With minor layout/reagent modifications, both lead and zinc circuits gained not only in retention time but as well in producing better grade products.Of course, the challenges are still there; they exist and only with the full support of operational data collection and metallurgical laboratory investigation success can come. That is why, we as professionals, can never stop in trying to make the most of what we have.INTRODUCTIONThe El Mochito Mine is owned by American Pacific Honduras S.A. de C.V. (AMPAC) a subsidiary of Breakwater Resources Ltd. Of Toronto, Canada. The mine is located in western Honduras, approximately 220 kilometers northwest of the capital city, Tegucigalpa and 90 kilometers south of the country’s second largest city, San Pedro Sula. The mine began operating in 1948 and to date has produced more than 19 million tonnes grading 240 g/t Ag, 3.5% Pb and 7.4% Zn. Production in 2005 was 700,190 tonnes grading 87 g/t Ag, 1.85% Pb and 6.61% Zn.Decreasing metal content in the ore followed by the lowest zinc price on the market in the last 15 years (see Figure 1) has reduced the cash flow and endangered to stop the operation."

Jan 1, 2007

By Tim O’Neil

More than 5,300 mining professionals from around the world attended the SME Annual Meeting and Exhibit, March 1-3 in Denver, CO. Seventy three technical sessions highlighted innovative technologies and applications for the development of mineral resources. And the exhibit featured 421 companies worldwide and 632 exhibit booths. The 1999 SME Annual Meeting had 10% international attendance. Professionals from outside the United States were guests at the first SME International Reception.

Jan 1, 1999

By J. Trow

Dowsing is really IESG which inductively locates electric gradients (dv/dx) on the flanks of SP anomalies. "Sensors" are in one?s head. The "meter" consists of one?s body, limbs, and two $.69 welding rods. The method was calibrated near Mamainse Point, Ontario, where IESG-negative chalcopyrite-bornite-chalcocite-native copper ores reveal mineral zoning related to the IESG-positive Keweenaw fault, down which oxidizing solutions moved. In Michigan, the IESG-positive Keweenaw fault suggests that oxygen-bearing solutions from the Jacobsville Sandstone moved downward to oxidize hydrothermal sulfur to produce native copper, and to supply sufficient water to satisfy Walter White.

Jan 1, 1992

By AIME AIME

THE twenty-second annual meeting of the Canadian Mining Institute was held at the King Edward Hotel, Toronto, on Mar. 8, 9, and 10, and was followed on the 11th by an all-day excursion to the International Nickel Refinery at Port Colborne. The meeting was very well attended and dealt with some of the most important matters, both technical and economic, that have ever come before the Canadian Institute. The question of licensing engineers is before the Canadian members as it is before our own in this country and the attitude of the mining engineers across the border is like that of the American mining engineers, opposed to the licensing of the mining. engineer, however they may feel toward the licensing of other branches of the engineering profession. It was well pointed out that such a law, had it been in existence in the last decade or two, would probably have prevented the rapid development of Canada's mines. Whereas one civil engineer can run a line of survey as well as another, perhaps, it is only a question in his case of whether he can or cannot survey. In the case of a mining engineer employed by a man with capital to invest in a development project, unless the man with the money has confidence in the judgment of his engineer the fact that he is a professional man would carry little weight in inducing a large investment toward the development of Canada's resources. It was also pointed out that although the Institute as a whole had not passed on the matter, it would probably be opposed to legislation aiming only for self-interest, but would be heartily in accord with legislation which could be shown to be for the service of the community at large.

Jan 1, 1920

By B. C. Christensen

The contract objectives are (1) to develop safe practice guidelines which will minimize the chance of fires in underground fueling areas and (2) to develop a low-cost, reliable, automatic fire protection system for underground fueling areas. The effort described by this report covers the period from 21 June 1976 to 30 September 1977 and accomplished the following tasks: ? Preparation of Data Plan and Data Acquisition, mainly through visits to sixteen mine sites and a literature survey. ? Analysis of the accumulated data, providing design inputs for (a) evaluation of the fire problem; (b) development of safe practice guidelines; and (c) development of recommended design concepts for automatic fire protection systems. ? Preparation of safe practice guidelines for underground fueling areas. ? Preparation of recommended design concepts for automatic fire protection systems for underground fueling areas. ? Design and fabrication of fire protection system for installation at Pine Creek Mine, Bishop, California. ? Install system and perform underground fire tests at Pine Creek Mine.

Jan 1, 1977

By LUIS ALBERTO TORRES-CRUZ

The assessment of liquefaction vulnerability is crucial to understanding the potential consequences of a tailings dam failure. The “Plewes method” is a relatively well-known and simple screening method to assess liquefaction potential based on results of cone penetration testing (CPT) which may be complemented with laboratory testing. The objective of the current work is to emphasise the screening nature of the method and its uncertainties when applied in tailings deposits. Specifically, the paper highlights the difficulties in assessing the intrinsic uncertainty of the method and the additional uncertainty that results from variations of the slope of the critical state line (λ10) along the depth of the CPT sounding. The results of the method are too uncertain for detailed characterisation of tailings even when a relatively low intrinsic uncertainty is assumed. However, the method characterises weaker soils with lower uncertainty (although still too high for detailed characterisation) than stronger soils. The uncertainty of the method is negatively affected by the relatively low λ10 values that are typical of nonplastic tailings. It is suggested that the results of the method should be presented in scatter plots in which the spread of the data is consistent with the uncertainty of the method.

Jan 28, 2021

A major domestic aluminum producer raised its price for primary aluminum metal from 44 cents per pound to 48 cents per pound, effective August 5, 1976. Other major producers have increased their list prices by equivalent amounts COAL: The strike which began July 19 in southern West Virginia enlarged by early August to involve approximately 80,000 miners in nine States. As of August 4, the aggregated loss of production is estimated to be 5.8 million tons. Reportedly, at this time, the railroads which serve the struck areas are feeling the largest impact with coke plants and electric utilities relying on stocks which are generally high.

Jan 1, 1976

By P. A. Cox

The purpose of the initial research performed under this contract was to determine the margins of safety in explosion-proof (XP) enclosures, which were designed and certified according to the current schedule (Schedule 2G). Results from this work provide baseline data on the current schedule, from which a new schedule can be formulated to give equal or greater levels of safety. Results and discoveries in the initial work led to an expansion of the contract to cover, additionally, weld quality in enclosure fabrication, reliability of enclosures with windows and lenses, and performance tests for enclosure qualification. Finite element calculations and hydrostatic tests revealed wide variations in the margins of safety in the enclosures studied; however, only one enclosure had a safety factor which was less than one. Results from a weld quality survey led to the recommendation of AWS Welding Standard D14.4 for the fabrication of XP enclosures. Based on other work, accelerated aging tests were recommended for qualifying plastics and adhesives that are used in some enclosures, and a Structural Performance Test was developed to test enclosure strength for a minimum static pressure of 150 psig.

Jan 1, 1982

By M. Ataee-pour, S. E. Jalali

So far, a large number of algorithms have been developed for the optimization of pit limits, most of which follow deterministic rules. In this paper, a new algorithm is introduced, which follows a probabilistic logic using the Markov chain process. The algorithm is implemented on a transition matrix that corresponds to the 2D conventional economic block model of the mining area. The probability of mining a block is proportional to the desirability it may provide. Applying this algorithm, the probability of mining each block is obtained, and finally, the optimum pit limits are defined as the pit, which provides the highest probability of mining. In order to validate the proposed model, a numerical example is given and the results of the algorithm are compared to those of a dynamic programming algorithm. A 2D analysis of the problem is discussed in this paper. Although dealing with 3D problems requires larger size matrices, the optimization method is the same and the algorithm does not need any smoothing.

Jan 1, 2006