Search Documents

By J. Steenkamp, A. L. Hannaford, A. N. Jones

O’Okiep Copper Co. Ltd.’s 45-kt/month (49,600-stpm) concentrator at the Spektakel mine in South Africa is comprised largely of reconditioned equipment from the old O’Okiep mill, which operated from 1940-1975. When combined with modern approaches to layout, crushing, classification, and flotation, a simple-to-operate plant was constructed at a cost of only $3.2 million.

Jan 11, 1982

By Harry C. Oussoren, James C. Miles

A new seven kilometer long subway line is being constructed through dense glacial soils under a major thoroughfare in Toronto. Eductor, deep well and vacuum wellpoint systems are being used to lower the water levels by as much as 16 metres for the construction of the twin tunnels and associated structures. The design and performance of the dewatering systems will be described. Unanticipated difficulties and their solution will be presented.

Jan 1, 1999

By M. Phillip Jameson, Paul Sennett

The beneficiation of kaolin by flotation has been practiced on an industrial level since 1961. A brief history of industrial kaolin flotation is given, with a description of the various processing schemes used by the companies that practice kaolin flotation. Some of the areas where improvements could be made in the beneficiation of kaolin are given.

Jan 1, 1989

By J. M. Gambogi

Demand for titanium minerals and pigments was nearly unchanged in 1996 compared with 1995. However, through mine expansions and process optimization by the TiO, pigment industry, the available supply of titanium minerals and pigments increased moderately. At the end of 1996, exploration, development and expansion programs were ongoing in the mining sector. But expansion projects in the pigment sector were delayed pending increased demand.

Jan 1, 1997

By Marina K. Peshkova, Izabell V. Pomorova

Computer modelling system for definition optimal way of in- vestment under condition of diverse directions of activities mining enterprises has been created. The main purpose of paper is to introduce the new scientific approach of finding effective variants of investment for mining industry under free market condition in Russia, it can be also interesting for domestic and foreign investors.

Jan 1, 1996

By D. Zaharaki

The present experimental study underlines the advantages of factorial design in environmental, geotechnical and waste management experimentation. A typical case study regarding solidification of metallurgical wastes is presented and the main effects and interactions of three main factors are determined in order to establish the optimum experimental conditions in terms of compressive strength. Finally, a regression equation that predicts accurately the real compressive strength of a specimen under various experimental conditions is derived.

Jan 1, 2005

By M. Cimini

The main objective of this paper is to propose a new sustainability parameter, called Visibility Indicator (VI), to describe the influence of mining operations on the visibility of the open works in the site from the surrounding land. A further goal is to point out a procedure for Visual Impact Analysis and Assessment (VIAA) of mining and quarrying operations in the phases of elaborating and evaluating of the project and depleting the resources. The Visibility Indicator has been computed taking into consideration the evolution of the area involved in the exploitation activity.

Jan 1, 2003

By R. C. Freas

Limestone is a basic raw material in the production of cement, lime, a wide variety of industrial products, and a significant percentage of the crushed stone produced in the United States annually. It is used in fluxes, glass making, mineral fillers, environmental applications such as flue gas desulphurization and water treatment, soil conditioners, animal feeds, and as a construction aggregate. This presentation provides an overview of limestone distribution in the United States, it’s production, the variety of products produced, and a brief review of the primary uses for limestone.

Jan 1, 2006

An insufficient hydrologic data base exists for most large and small coal basins in Alaska owing to the lack of need in the past to collect data. The runoff process is insufficiently understood which is complicated by specifically northern phenomenon, and the lack of understanding of hydrologic relationships in permafrost environment. This paper presents an understanding of the hydrologic effects of frozen ground and presents methods by which the influence of surface mining upon the hydrologic balance can be analyzed.

Jan 1, 1988

By Shahid A. Pirzada, Milton Manrique, Patrick R. Taylor

Microsilica or silica fume is a waste material generated from silicon or silicon-containing alloys producing electric furnaces. One of its usage is as an additive in the concrete production. This investigation describes a process to use microsilica as a feed material to produce fine silicon carbide. A thermal plasma reactor is used to convert this waste material into a value added ceramic. Details of the theoretical considerations, experimental work, and characterization are presented in this work

Jan 1, 1995

By David G. Rasmussen

With low commodity prices and continuing high operating costs, the mining industry must revise planning and operating to take advantage of every tool available. Conveyors operated within open pits are such a tool. Dravo engineers have designed conveyor systems into pits as prime movers in unique situations. Three cases are presented with economic comparisons made to conventional truck haulage. Increasing energy and labor costs tend to make conversion of prime haulage from trucks to conveyors. Long term pit planning and scheduling reduce the effects of conveyor inflexibility.

Jan 1, 1983

By D. Panda, P. K. Sahoo, A. S. Rao

The waste phosphogypsum produced by Paradeep Phosphate Limited (PPL) at Paradeep (Cuttack, Orissa, India) consists primarily of calcium sulfate with small amounts of phosphoric acid, calcium fluoride and other harmful components. Presently these are dumped as waste. In this work, laboratory trials have been made to utilize the calcium sulfate present in the phosphogypsum to prepare usable products like ammonium sulfate, calcium carbonate and magnesium sulfate.

Jan 1, 1994

By Jerry Harrington, Brad Wigglesworth, David C. Beling

Commercial operations at the open pit, heap leach Crofoot Mine commenced in April, 1988. Approximately 13,600 tonnes (15,000 st) of low grade pregnant solution are treated daily using a Merrill-Crowe circuit. Acceptable gold recoveries from these low grade solutions can be obtained by optimizing solution pre-treatment prior to zinc addition.

Jan 1, 1990

By Janusz Cygankiewicz, Marian Branny, Józef Wactawik

The paper presents mathematical model of concealed fire. We consider a porous medium (goaf, coal fissures) through which air flows. The set of equations is constituted by transient, two dimensional mass, momentum and energy balance equations with sources describing oxygen loss and heat generation caused by coal oxidation. Paper presents several examples illustrating the phenomenon of spontaneous heating in goaf areas behind longwall faces.

Jan 1, 1997

By D. Y. Jiang, X. S. Tan, S. S. Peng

Expansion strain and stress that exist in floor rocks and that are due to the presence of water, were derived from a basic theory of mechanics. The results indicate that water stress and strain are the important factors that cause failure of the floor rocks and induce floor heave.

Jan 1, 1994

By S. Bhattacharjee, S. K. Singh, R. K. Galgali

A method for the preparation of zirconia- toughened mullite using dc plasma is presented. An indigenously developed 50-kW thermal plasma reactor is used for the preparation of zirconia-toughened mullite using a dissociated zircon and alumina mixture. Both XRD and SEM studies of the product confirmed the formation of mullite and zirconia. The zirconia grew as equiaxed grains of uniform size (~5 µm) in a mullite matrix.

Jan 1, 2002

By T. N. Singh, M. M. Singh, R. B. Singh

Fly rock is common when blasting shallow holes and during secondary blasting. Although the required quantity of explosives for secondary blasts is less, noise and fly rock can have an enormous environmental impact. This paper mainly deals with field experiments on blast-design parameters and addresses some precautionary measures that can be taken when pop shooting.

Jan 1, 2000

By I. P. Giannopoulou

Flotation tailings resulted from the mineral pro-cessing of mixed sulfides ores represent the main source of the generation of acid mine drainage (AMD). These solid wastes remain un-utilized in the disposal areas (tailing dams), while for their stabilization and the immobilization of the contained heavy metals highly costly management techniques are required. In the present paper the geopolymerization of the flotation tailings resulted from copper sulfide ores dressing process is investigated, as an alternative method for their treatment aiming at immobilize the contained heavy metals and utilize the produced materials as raw materials in the construction materials industry.

Jan 1, 2006

By R. W. Williams

Consequent on the development of digital computers the importance of analog simulation as a means of studying engineering problems has diminished in recent years. The general-purpose nature of a digital computer ensures its applicability to a wide range of tasks whereas an analog simulator is confined to the one specific use for which it was designed. Nevertheless the analog technique remains attractive in its application to certain aspects of the study of mine ventilation networks, for reasons which will now be developed.

Jan 1, 1980

By J. Changsheng, Z. Youdi

Based on the criteria of maximum net present value per ton of reserves and on the optimum matching of some other essential parameters, a comprehensive optimization model of surface-mine production rate is developed using system- engineering approaches and using the theory of economy of scale. A mine is then selected to demonstrate the application of the model.

Jan 1, 2000