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For handling rough rock, the shovel-train system is unexcelled. The ideal application is a physically large, but not excessively deep, open-pit mine from which the coarsely blasted ore and waste must be transported distances in excess of three miles. If, in addition, a high production rate is to be maintained, railroad haulage will probably afford a lower cost per ton transportation than will any other haulage method. Relatively gentle grades must be employed- usually 3% for uphill hauls and 4% for downhill hauls. The greater the differences in elevation the greater are the railroad track grade space requirements. By way of illustration, a 3% ramp out of a pit only 300 ft deep must be almost two miles long. Mainline track locations should be selected carefully so that the frequency of movements during the life of the mining operation is minimized. This applies both to ore and to waste haulageways. Such moves are not only expensive but difficult to execute without adversely affecting production rates. The large mine affords greater opportunities for judicious location of semi-permanent trackage.

Jan 10, 1967

By Steve Kral

The Red Dog zinc-lead deposit, said to be the world's second largest, is located inside the Arctic Circle in northwestern Alaska - a location too harsh and remote for some mining companies but just right for Cominco Ltd. The complex has been in operation since November 1989 and is producing 508 kt/a (560,000 stpy) of zinc concentrate, 109 kt/a (120,000 stpy) of leadconcentrate and 45 kt/a (50,000 stpy) of an Imperial Smelter Feed, a combined zinc-lead mixture that is too small to separate. All of this concentrate production derives from a relatively modest mine production of 5.4 kt/ad (6000 stpd) extracted from a surface pit. Despite being a high-grade zinc-lead deposit, Red Dog's metallurgy is complex, requiring a very fine grind and use of column cells for flotation. The Red Dog complex is located in the DeLong Mountains. They are characterized by eight stack and folded thrust blocks that contain sedimentary and igneous rocks. The Red Dog deposit is located in the second lowest thrust and ist hosted by late Mississippian to Permian age black shale, the Ikalukrok member of the Kuna formation. The Red Dog mining complex is operated by Cominco Alaska, Inc., a wholly owned subsidiary of Cominco American, Inc, which, in turn, is owned by Cominco Ltd. In 1980, the deposit region was acquired by NANA Corp. as part of the Native American Claims Act Settlement of 1971. NANA is one of 12 such Native Corporations in Alaska. In 1982, NANA and Cominco American signed a develop¬ment agreement and formed Cominco Alaska to manage the project.

Jan 1, 1992

Homestake's Bulldog Mountain Operation near Creede, Colorado, in the San Juan Mountains at an elevation of nearly 2,750 m (9,000 ft), is subjected to short summers and long cold winters. Creede’s history dates back to 1889 when silver ore was discovered; and by 1892 production of over a million dollars per month was being shipped from mines located along the Amethyst Fault. The Bulldog Mountain Fault remained relatively untouched by the early prospectors. The United States Geological Survey recognized the potential of this fault in 1960, which led to the staking of many claims over the structure. Homestake leased properties in 1963 and in mid- 1964 a tunnel was started at the 2,956 m (9,700 ft) level with encouraging mineralization being encountered. In 1968 a decision was reached to build a flotation mill of 318 mtpd (350 stpd) capacity. The erection of the mill was completed in early 1969, six years after the first exploration was begun. Since initial start-up, extensive drifting has been done on several separate levels. Two underground hoist installations serve the various levels and many thousand feet of vertical mining operations. Due to the unconsolidated nature of the vein, a new unique underhand cut-and- fill mining method was developed. This procedure is the reverse of the normal cut-and-fill and proceeds from the top down under cemented sand fill, which, while expensive, has greatly reduced s toping hazards. Prior to 1977, a considerable quantity of silver was lost in the slime fraction of the ores processed because of oxidation and other inherent characteristics of individual minerals. Due to Homestakefs favorable experience in treating the slime fraction of the Lead, South Dakota gold ores, experiments with leach methods to recover silver from the slimes by Carbon -In -Pulp offered' the potential for additional silver recovery. Work was begun on the Carbon-In-Pulp plant in April 1976 and completed in December of that year at a cost slightly exceeding $2 million. The C. I. P. plant was designed for 136 mtpd (150 stpd) of current plant slimes plus 227 mtpd (250 stpd) of slimes dredged from the old tailings during the summer season. The sand fraction of the flotation

Jan 1, 1981

By F. Qian

An impinging gas jet on a liquid surface is found in many industrial process systems such as electric arc furnace, welding, steel-making operation and others. Fundamental understanding of the interaction of a gas jet on a liquid pool can provide important insights into process behavior resulting in improved efficiency. A numerical model is developed for solving the flow fields of both impinging gas jet region and liquid pool below, in which the deformed interface shape is predicted simultaneously. Using curvilinear coordinates, the Navier-Stokes equations of each phase are solved separately through coupling of static pressure, shear stress and velocity at the interface. Several cases for jet distances and flowrates were investigated both numerically and experimentally with an air-water model. Favorable comparison of numerical results with experimental data confirms the validity of the present numerical approach. An existing phenomenological model for 'penetration depth' prediction was extended for smaller 3et exit height to jet diameter' ratios.

Jan 1, 1995

By Dave Willis

Two hundred and thirty million tons of coal! That is what the Burlington Northern (BN) railroad anticipates that it and the Chicago North Western railroad (CNW) will haul out of the southern Powder River Basin l (see map on page 966) in 1994. Put that 209 Mt (230 million st) into railroad perspective. Current average train size is 113 cars. With each car transporting 94 t (103.5 st) of coal, each train averages 10.6 kt (11,700 st) of coal. Simple division shows that 209 Mt (230 million st) of coal equals 19,658 trains a year. So BN and the CNW must move 54 loads a day out of the Basin. Every load, of course, has an empty side of its cycle. This means that 54 loads a day translates into 108 total trains a day, or 39,420 trains a year through the southern PRB.

Jan 1, 1994

By John L. Hatton

The author will introduce and describe the nature of Fiberglas-Reinforced Plastics. Successful applications of corrosion-resistant structures will be shown and described, including pipe, ducts, tanks and other equipment. These structures are generally designed to handle corrosive liquids and gases and have proved both satisfactory and economical in service in various industries in Canada. The specification of structures will be discussed in relation to materials, construction and workmanship, physical properties and methods of testing.

Jan 1, 1970

Jan 1, 1949

By N. I. Tyushkova

This is a brief survey of the technological solutions for deep cleaning of baddeleyite?s concen-trate. Baddeleyite is part of kamaphorite of composite apatite-magnetite ore in alkaline-ultrabasic mountain range of Kola Peninsula. Baddeleyite?s concentrate, which is being produced by Kovdorsky GOK (ore mining and processing enterprise) contains 97.5%~98.5% (Zr?2 + ?f?2) and also scandium oxide (0.05%). It is usually used without any chemical processing. World demand for zirconium oxide is constantly on the rise. Its consumption grows in ceramic industry and in high-tech spheres. That?s why the demand for its purity is very important nowadays (additional cleaning from phosphorus, silicon, iron, aluminium). The mechanism and kinetics of interaction of activated bad-deleyite with sulphuric acid has been studied as well. While applying method of mathematical mod-eling it was confirmed that the mechanical activation is effective for the intensification of sulphation process of baddeleyite?s concentrate with the aim of purifying it from dirt. The use of the calculated optimal regimes allows to reduce such technological operation factors as: temperature, the du-ration of process, the sulphuric acid consumption. It also allows to determine the conditions of anticipatory abstraction of scandium and main dirt in solution in comparison with zirconium oxide.

Jan 1, 2014

Jan 1, 1965

By Z. M. Zavodni, M. K. McCarter

This paper identifies physical conditions responsible for past instability of the Main Hill area in Kennecott Copper Corporation's Bingham Canyon Mine, Bingham Canyon, Utah, and describes successful stabilization techniques employed in this slide zone. Geotechnical highlights of recent slides are presented, including monitoring, geological engineering data collection, hydrology, physical rock properties, and stability analyses. Local conditions responsible for slope movement in the Main Hill zone are: (1) high pore water pressure that causes a substantial decrease in real and effective material strengths; (2) continuous structural systems that allow sliding in the more competent rock zones; and (3) broad areas containing fractured, altered , and incompetent rock and soil- like materials. The failure mode is structurally controlled and involves a circular-type soil failure in the toe region initiated by excessive pore water pressure. A surface mapping method is presented which assigns rock mass quality on the basis of block size and rock substance strength. This site characterization technique has successfully predicted slide boundaries and failure modes; used in conjunction with laboratory determined shear strengths, it has provided basic input for calculating slope safety factors in the Main Hill slide zone.

Jan 1, 1977

By Paul-Henri Girard

La Mine Agnico-Eagle division Laronde situé à Cadillac, est un producteur d?or, d?argent, de cuivre et de zinc. Cette propriété est situé dans les cantons Bousquet-Cadillac le long d?une des ceintures géologiques les plus productives au monde. La mine Laronde a débuté la production en octobre 1988 à un rythme de 1360 tonnes par jour. Ensuite, elle a augmenté son rythme de production successivement à 1800 TPJ en 1990, 3300 TPJ en janvier 2000 et 4500 TPJ en octobre 2000. Agnico-Eagle, fondé par feu Paul Penna, a toujours eu comme politique la participation des employés aux décisions de la compagnie pour le déveleppement de celle-ci. Cet écrit va permettre de mieux comprendre la façon dont la division fût développé.

May 1, 2001

By J. B. Mawdsley

A LITILE north of the geographic centre of the Province of Saskatchewan, 150 miles north of the city of Prince Albert, is a narrow green-stone and sedimentary belt of pronounced structural characteristics. This belt, generally known as the Sulphide Lake belt, is about two and a half miles wide. During the past three years prospecting has uncovered numerous gold-bearing showings occurring chiefly along the centre of the belt for a distance of at least nine miles. The number of these showings, the nature of some of them, and their relationship to strong structural features, make it altogether likely that intensive work will eventually locate ore-bodies that will be of economic importance. The discovery of gold in the fall of 1938 on the south shore of Mackay lake, about five miles northwest of the Sulphide Lake gold-bearing belt, indicates that there are neighbouring zones of interest. This paper, an attempt to outline the present status of the interesting mineralized belt, is based largely on the information gained on a five-day tour of this district, made in August, 1939, on behalf of the Department of Natural Resources of the Province of Saskatchewan. The Sulphide Lake belt is named after a small lake centrally located in it. This lake and others are just north and within short portage distances of some of the long bays along the north shore of Lac La-Ronge, an irregular, island-studded lake, about twenty miles in diameter, in relatively rocky Precambrian country, just north of the Palaeozoic contact. The fur-trading post and settlement of Lac La-Ronge is on the west shore of this lake and a road, now under construction, will shortly link this community with the city of Prince Albert. In the past, the most direct route was an indifferent canoe route, in part following Montreal lake and river; more recently, the aeroplane has made this section easily accessible.

Jan 1, 1940

By Robert E. Barieau

General expressions for evaluating practically all the thermodynamic properties of a fluid from a single equation of state are derived. Most of the formulas are expressed in terms of the compressibility factor, with this factor being an explicit function of the temperature and the molal density. Similar expressions are given using reduced variables.

Jan 1, 1967

By Honggang Zhong, Tan Yi, Qijie Zhai, Zhao Dan, Xinping Mao, Huigai Li

"The influence of superheat degree on the distribution and volume content of inclusions were studied in 65Mn thin slab produced by compact strip production(CSP) in Zhujiang Steel in China, The results showed that the diameters of inclusions are mainly less than 5µm. Most of the inclusions gathered at the 1/4 thickness direction for the thin slab of 27? superheat degree, compared with the center position for that of 37?. There are more inclusions larger than 50µm in the low superheat samples, which is caused by the short floating time. In addition, the inclusions were observed and analyzed by metallurgical microscope, SEM and EDS in order to ensure their composition, type and further find their source. It was find that the types of these inclusions mainly are Al2O3, SiO2,CaO and their composites, a few of them are TiN and MnS.IntroductionIt is well known that inclusions have a great impact on the strength, plasticity, fracture toughness, cutting performance, fatigue property and corrosion resistance of steels. Especially, with the demand for thinner slab, the cleanness is increasingly becoming more significant as a quality criterion[1]. High manganese and carbon steels not only demonstrate high strength but also proper plasticity. There are many problems unsolved for 65Mn steel as a result of the low solidification rate, bad thermal strength, crack sensitivity and low casting temperature[2,3].The superheat of the molten steel has a great impact on the erosion of refractory lining, molten steel fluidity and non-metallic inclusion behavior[4]. The serious erosion situation of ladle lining, nozzle and casting tundish will give rise to more inclusions at a high superheat. Meantime higher superheat will make second dendrite arm spacing coursing and element segregation which lead to inclusion, bubble formation and shrinkage cavity. On the contrary, it is hard for non-metallic inclusions to float up with a low superheat value. Inclusions of 65Mn steel, which produced in different superheat condition by CSP, were studied for the sake of higher slab properties including statistics and EDS analysis."

Jan 1, 2012

By Hong Ro Lee, Seang Suk Cho, Byung Sun Chun, Chang Whan Won

"The preparation of Al203-SiC-TiC composite powders was studied by SHS process using silica (source of Si02) powder instead of Si which is expensive. And, aluminum powder was used as reducing agent of silica and charcoal activated was used as carbon source. Effects of the molar ratio in raw material mixtures and compaction pressure and initial temperature of reactant on the products and combustion process were studied. The most important variable affecting the synthesis of Al203-SiC-TiC was the molar ratio of carbon. The combustion reaction generated in powder state without preheating. But the unreactants exist in the product on all molar ratio. When the preheating temperature is over 400 °C, the combustion reaction was able to be generated in pellet state. Without preheating, the combustion reaction was possible by Ti02 addition. The optimum condition in this system was the molar ratio of Si02:Ti02:Al:C=2.5:0.5:4:3.1. INTRODUCTIONCeramics have demonstrated a capability as a cutting tool, especially in competition with WC-Co cermets (ceramic-metal composites) as inserts for metal turning and milling operation. The advantage of ceramics compared with carbides is retention of high hardness, strength, and chemical inertness to temperatures in excess of 1000 ·c . This allows use of the ceramics at much higher machining speeds than can be tolerated by carbides. However, the ceramics have lower toughness than the carbide materials, and have only been used successfully in the limited operations of turning and milling. There are several classes of cutting tools. The addition of TiC or PSZ, or both, and reinforcement with SiC overcame the poor fracture toughness and thermal-shock resistance that limited Al203 use in the past [1]."

Jan 1, 1998

By R. T. Swinderman

This paper discusses how many of the common practices in conveyor specification and design are out of date compared to the current expectations of users for safe, serviceable, reliable, and fugitive material-free conveyance of bulk solids. Ten of the most common mistakes made in the specification and design stages related to user expectations are reviewed along with the cost vs. price implications of those decisions. A general specification and design hierarchy that designers can use to improve conveyor design is included.

Jan 1, 2010

By John J. Mulligan

The Bureau of Mines sampled a gold-bearing schist series 50 miles east of Nome near Bluff, a dormant mining camp on the southern shore of the Seward Peninsula, Alaska. Gold is unevenly distributed through a section of a schist series that extends from the coast northward 4,500 feet. In this section the schists dip westward 20 to 38 degrees and have an outcrop width of about 1,000 feet and a normal width of about 500 feet. An intensely fractured zone within the schists averages 0.015 to 0.017 ounce of gold and 0.03 to 0.05 ounce of silver per ton for outcrop widths of 200 to almost 500 feet. The grade of the remainder of the schist series ranges downward to scant traces. Gold eroded from these schists collected in solution channels in metalimestones to form the Daniels Creek placers, which also extend from the beach southward under the sea for an unknown distance. The lode sources of the gold placers elsewhere in the southern Seward Peninsula may be similar schists that occupy a similar position in the metasedimentary series.

Jan 1, 1971

By Angelus S. C. Owili-Eger

The past decade has witnessed an unprecendented proliferation of groundwater computer models. Some of these numerical models were developed for the purpose of simulating groundwater movement in mining environments and predicting inflow rates into active mines. However, a general acceptance of these models as routine planning tools by the mining industry has been slow. Until recently, the major use of these models in the industry is by consultants. There are several reasons that have contributed to this situation. Some of these factors - include scarcity or non-existence of an appropriate data base information required for executing these models, the difficulty and costs involved in acquiring data, and the fact that the instructions for using these models are often too involved and time consuming. Today, however, the state-of-the-art technology has been advanced to a level where numerical models can be routinely used to simulate and predict inflow rates into active mining environments. Such environments include highly fractured (longwall) and deforming flow media. Features integrated into these comprehensive and yet easy to use models are double-porosity-pressure, multiphase, and non-darcian flow conditions. This paper reviews the role that computer modeling has played in mining-related operations by presenting several case studies and the state-of-the-art tools currently in use. Included will be some of the practical field applications that have been compiled during the past decade.

Jan 1, 1986

This paper presents a quantitative approach to the problem of determining design capacity and field dimensions of underground coal mines using room- and-pillar mining systems. In evaluating these design variables, relationships among mining costs, number of production sections in mines, location of central shafts, mine field dimensions, section production, mine output, and cost of production losses due to underground man-traveling are analyzed. Thereby the unit cost of coal is expressed as a function of the design variables as well as input parameters such as seam angle, seam thickness, seam depth, underground traveling speed of men, mine recovery and plant recovery. The problem is then formulated as a nonlinear optimization model in terms of minimizing the unit cost of coal subject to a set of constraints and solved analytically for flat seams and numerically for inclined seams. Sensitivity analysis of the variables is also included in the paper.

Jan 1, 1987

By K. N. Han, P. B. Queneau, Bruce W. Cavender

Measures of metallurgical performance, such as recovery rates or mass balances, are frequently based on point estimates of operating conditions in the system of interest. Because the processes being measured are dynamic, a range of uncertainty accompanies each measurement; this uncertainty is reflected in the accuracy with which the calculated result describes the true metallurgical performance. In stochastic modeling, a range of probable values is used in place of a point estimate to describe each variable. The calculated result takes the form of a distribution, delineating both the magnitude and probability of potential outcomes.

Jan 1, 1993