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By Subash Chander, B. Arnold

Many developments have occurred in coal flotation with regard to increasing recovery from the flotation circuit and its impact on overall coal preparation plant recovery. This includes innovative design of flotation circuits, equipment modification and development, methods of enhancing the use of reagents, effect of slimes, and recognizing the effect of water chemistry. This paper will review recent advances and present some guidelines to improve process efficiency.

Jan 1, 2005

By Donald P. Richards, John F. Abel

Geotechnical site investigation for new mine shafts can reduce the level of design uncertainty for shaft linings. The parameters which determine the lining strength required include rock strength and hydrologic properties, the in situ stress conditions, and the concrete strength. These parameters are applied to analytical methods of shaft lining design using the plastic and clastic assumptions of rock response to determine the required lining thickness to maintain the stability of the shaft excavation.

Jan 1, 1982

By C. Jay Hodgson, Adrienne C. L. Larocque

The Mobrun VMS deposit in northwestern Quebec does not fit the classic Noranda type model, but exhibits characteristics more consistent with a Mattabi-type deposit. The orebodies are underlain by fragmental volcanic rocks indicative of explosive volcanism in shallow water. Felsic volcanic rocks are more abundant than mafic rocks. Alteration assemblages comprise chlorite, carbonate, sericite, and quartz. Broad semi-conformable alteration occurs high in the footwall to the 1100 lens. Mobrun occurs higher in the stratigraphic sequence than most of the other deposits in the Noranda camp. In this part of the stratigraphy, zones of pervasive carbonatization may be more useful guides for exploration than zones of silicification.

Jan 1, 1993

By J. J. Lewis

The chapter describes how several OR techniques assisted the planning of a major new UR project. A computer system was developed to analyze reserves distribution and potential of possible underground layouts, to assist in choosing the location and size of access points. Manpower requirements of each proposed working plan were assessed and matched with the potential recruitment of skilled and unskilled labor. Computer simulations were used to determine the optimum capacity for coal preparation plant and surface bunkerage. For the overall assessment of robustness, financial modelling and risk analysis techniques were adapted to the special requirements of new mines.

Jan 1, 1979

By Howlett P. F, Courtley S

A problem with secondary breaking at one of the mines of Pasminco Mining led to a study of new rock breaking technologies. Many of the techniques being developed had emerged from the thrust in the USA for continuous drill=break excavation. Such approaches to rock breaking highlighted the applicability of what would normally be classified as tunnelling techniques, to the secondary breaking sector - and possibly the reverse. As a direct result of the investigations for suitable technologies, Pasminco Mining supported the development of two improved rock breaking methods specifically targeting secondary breaking, one of which could be applied to continuous excavation.

Jan 1, 1993

By T. N. Dixon, J. E. Briggs

A study was made of numerical techniques for solving the large sets of simultaneous equations that arise in the mathematical mode ling of oil reservoir behavior. It was found that noniterative techniques, such as the Alternating Direction Implicit (ADI) method, as well as some other finite difference approximations, produce oscillatory or unsmooth results for large time steps. Estimates of time step sizes sufficient to avoid such behavior are given. A comparison was made of the Point Successive Over-Relaxation (PSOR), Two-Line Cyclic Chebyshev Semi-Iterative SOR (2LCC), and iterative ADI methods, with respect to speed of solution of a test problem. It was found that, when applicable, iterative ADI is fastest for problems involving many points, while 2LCC is preferable for smaller problems. INTRODUCTION With the advent of high speed, large memory, digital computers, there has been an increasing emphasis on the development of improved methods for simulating and predicting reservoir performance. Two-dimensional, three-phase reservoir models with various combinations of PVT effects, as well as gravity and capillary forces, are common throughout the industry. Such models are also available through consulting firms, to anyone desiring to use them. Three-dimensional models will probably be practical in only a few years. We conducted a study of some of the numerical methods used for solving the large sets of simultaneous equations that arise in such models. A typical set of equations for a reservoir model is shown below:

Jan 1, 1969

A magnetometer survey 'was the Darkes Forest area between 1968. The instrument used was model MZ4 with sensitivity 9.4 conducted over part of 30th April and 3rd May, an ABEM torsion magnetometer gammas per scale division. The survey consisted of a closed magnetometer loop along lines cut for a previous magnetometer and seismic reflection survey by Wongela Geophysical in March, 1968. The magnetic results of the previous survey were not satisfactory in some areas and are presented as a comparison in instrumentation. Station separation in the present survey was 100 feet with tie-in readings at shot points of the previous survey (usually 1320 feet apart)

Jan 1, 1969

By Frédéric Flament, Mary Goldman, Gille Barbery

"Pilot plant testwork on autogenous and semi-autogenous grinding was conducted at the Centre des Recherches Minérales du Québec (CRM) to investigate the effect of ball addition, solids concentration in the feed, specific energy consumption and feed size distribution.A mathematical model that incorporates breakage and surface mechanisms of loss of mass was developed to predict load size distribution of autogenous and semi-autogeneous mills. An empirical model was used to predict product size distribution of autogenous and semi-autogeneous mills.IntroductionAutogenous (AG) and semi-autogenous (SAG) grinding circuits offer potential capital and operating cost savings when compared with conventional grinding. Empirical relationships have been developed to calculate specific power consumption for SAG mills using pilot plant test results (Mular et al., 1989; Barrett and Allan, 1986). Empirical models can be obtained from plant practice data but are applicable only to the particular ore and set of operating conditions used in the model. Grinding mechanisms have to be taken into account in order to develop a model that can be applied to different ores and mills.In AG and SAG, the ore itself acts as grinding media, with the finer sizes being crushed by the coarser ones. Surface mechanisms of loss of mass, in which the inner core of the particle remains intact, also take place. In SAG milling, the effect of balls also has to be taken into account. The role of each one of these mechanisms changes with particle size and the model has to account for such changes."

Jan 1, 1991

On Wednesday 11th November, 1970, a series of violent explosions occur-- red within No.1 Basic Oxygen Steelmak- ing (B.O.S.) furnace at the Whyalla Works of the Broken Hill Proprietary Co. Ltd., (B.H.P.) when the furnace was moved immediately prior to tapping. Water from a burnt out flux chute had flooded the bath while the furnace was tilted slightly towards the tapping side waiting to tap. Although no one was injured, dam- age in excess of $54 000 was caused to the hood and superstructure. The water hydrated the burnt dolomite refractory lining some of which sub- sequently collapsed exposing bare fur- nace shell over part of the cone.

Jan 1, 1975

By Fernando Valdez Nolasco

Dada la crisis minera por la baja de precio de metales en América Latina y principales minas del Perú, se planteó un modelo de gestión que resuelva la situación. Dicho modelo consta de cuatro etapas: la primera está basada en la visión, valores y objetivos estratégicos; la segunda, en el análisis estratégico; la tercera, en la construcción de la estrategia y la última, en el control estratégico. En ese sentido, el presente trabajo señala la implementación, seguimiento y control íntegro de estos procesos como la participación de lás áreas de la empresa y los canales de comunicación, de forma que se logra incrementar las ventas y bajar el cash cost en la empresa minera.

Nov 1, 2016

By M. Z. Rashad, H. A. El-Sageer

The intersections of numerous joint sets at the surface of tunnels of the Abu-Tartour project in Egypt create blocks of irregular shape and size in the rock mass. Although most of these blocks are unable to move into the free space of the tunnel, a few key blocks are capable of such movement. In addition, as soon as they move, some restrained blocks will be liberated. The aim of this work is to find the removable key blocks of the walls, floor, roof and corners of a portion of the tunnel under jointed surface rocks and then determine the best tunnel direction.

Jan 1, 1993

By Claes G. Björk

Over the past decade mined unlined rock cavern storage for crude oil and refined products has become economically more attractive. This trend is likely to continue, primarily due to advances in excavation methods, rising steel costs for above ground tanks and larger capacity requirements. The construction experience related in this paper comprises the excavation of more than 80 storage facilities (total capacity 90 million bbl) for crude and refined products ranging from propane to heavy fuel oil. This paper also deals with the experience gained as well as the problems derived from the utilization of these oil storage facilities.

Jan 1, 1981

GRD Macraes Limited, owners and operators of the Macraes and Reefton Gold Project in New Zealand, have taken up the challenge of sustainably producing in excess of 300 000 ounces per annum within five years.GRD Macraes is well on target to achieve the forecast of 170 000 oz at a cash cost of A$310/oz for the 2002 financial year, with our Reefton operation set to add about 70 000 û 80 000 ounces per annum from late 2003.At the end of 2001 GRD Macraes Limited had resources of 5.5 million oz with reserves at 2.8 million oz.

Jan 1, 2002

By K. C. Shaver

Detailed examination of the Sloan Ranch diamond prospect has shown that the Sloan 1 diatreme, the Sloan 2 dike, and the Sloan 3 horizontal sheet complex are all parts of the same kimberlite complex. Geologic mapping, geophysics, soil chemistry, test pitting, and drilling all helped to delineate the structure. Bulk sample testing yielded moderate grades with encouraging gem-to-industrial ratios, but no large stones were recovered. These test results, along with supporting mineral chemistry data, suggest that the Sloan Ranch complex is analogous to sub- economic occurrences located near the margins of the Archean cratons in southern Africa.

Jan 1, 1987

By Barclay C, Jacobsen M, Towsey C

The Emperor Gold mine at Vatukoula, Fiji, is a nine million ounce gold telluride deposit. In January 1992, the mine was on the verge of closure when the current management team took charge. Losses had been incurred for two consecutive years and the published resource amounted to less than five years of production. Relationships with the workforce, the government and the general public were poor. Today, the mine has recorded three consecutive years of profit, has resources that will support the operation for at least 20 years and has excellent relationships with employees, government and the general public.

Jan 1, 1997

By Jorge Blacker Bendezú

Existen historias registradas sobre descubrimientos de ciertos elementos de la Química que mostraban propiedades especiales de difícil identificación. En este grupo de elementos químicos (17) se encuentran "las tierras raras" que, conjuntamente con otro grupo de sustancias estratégicas, contribuyen al cabal desarrollo de la ciencia y su correcta aplicación mediante su permanente progreso tecnológico. Por ello, el presente texto señala los mitos y realidades sobre estas "tierras raras" y otros metales estratégicos (comercio, alternativas de explotación y costos)

Jan 1, 2014

By Conrad Parrish

As originally conceived, this paper was to address the costs of environmental compliance, focus on environmental impact statements, and describe how those costs impact mining projects. The intent was to do wide ranging mathematical analyses to demonstrate the varying impacts on mining projects depending on their size, timing, return on investment and other salient project features. The initial portion of the numerical analysis necessary to this purpose was performed. The results showed a pattern of impacts familiar to the mining industry:

Jan 1, 1991

By David Fisk

Mining: Current Business Environment ? Commodity prices are high, but cyclic ? Increasing global competition ? Equipment costs remain high ? Maintenance costs continue to increase ? Aging experts with ?tribal knowledge? are leaving/retiring ? High metal prices multiplies theimpact of downtime on production and profitability

May 1, 2008

By Bruce Peberdy

Outline ?Building Systems ?Climatic Effects ?Thermal Effects ?Building Components ?Building Materials ?Structural Deterioration ?Maintenance Considerations

Nov 1, 2011

By Robert Glass Cleland

[DATA OF THE YEAR 1950 COMPARED TO 1909 (FIRST CONSOLIDATED REPORT) CONSOLIDATED NET INCOME Without deduction for depletion of mines $ 42,395,465 $7,337,252 After deduction for depletion of mines $ 4,112,604 $7,337,252]

Jan 1, 1952