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By Kenichiro Yamamoto, Masaharu Murakami, Toshio Matsuzawa, Yoshiyuki Ikeda

In a series of tests, we examined the dynamic shock resistance of Emulsion Explosive in water and compared it with that of Dynamite and Slurry Explosives. Both the distance between donor and acceptor charges and the delay initiation timing of the acceptor charges were varied. The resistance to dynamic shock varied with the properties of the explosive. In the case of emulsion explosives, there seems to be a certain proportional relationship between the critical detonation distance and the delay initiation timing. Some blasting results with emulsion explosives are described.

Jan 1, 1983

By Jan K. Wolski

This paper presents a simple method for determining air temperature gradients along a tunnel with time-dependent intake air properties. The variable intake air properties may be the flow direction and rate, air temperature and humidity, and the carbon dioxide content. The transient intake air properties are simulated by a series of steady intake air conditions, using a superposition method. The mathematical model was verified by reduced-scale experiments in the Waldo mine. The method may be usefull in conditions where the computation speed is more important than the precision of the results.

Jan 1, 1995

By Gerald G. Schmitt, Richard D. Dick

Continuous Reflectometry for Radius vs Time Experiments (CORRTEX) was used to monitor several conditions of blasts such as the detonation velocity of the explosive column, the functioning of different types of initiators and initiation schemes, and the behavior of the stemming column confining the explosive. The CORRTEX data were also used to deduce the occurrence of dead pressing of ANFO slurry. Measurements of propagation speeds of shock waves in the stem column with various cables allowed some conclusions concerning bridging, stem failure, and stress levels in the stem.

Jan 1, 1985

By B. Towson, R. F. Dalton, G. W. Seward

This paper reviews the successful application of oxime reagents for the solvent extraction of copper and considers the role that well focussed research initiatives can play in bringing further radical change to the metallurgical industry. Particular reference is made to the Cuprex Metal Extraction Process (CMEP), for the treatment of low grade or difficult to treat sulfide concentrates, using the reagent Acorga CLX- 50 to recover the copper and the reagent Acorga ZNX-50 for the recovery of zinc from chloride solutions. Other new extractants, currently in development, are also referenced.

Jan 1, 1994

By C R. Headley, S O. Hille, N P. Jacob

The redevelopment of the Telfer Gold Mine in the Pilbara region of Western Australia was primarily based on the construction of a 17 Mtpa dual train concentrator coupled with open pit and underground mining operations. The unique copper-gold orebody at Telfer requires the application of complex flotation conditions normally reserved for base metal concentrators, where two competing minerals are managed into separate products. This paper describes the commissioning of the flotation circuit, the process modes and the master/slave relationship that flotation has with a variable orebody.

Jan 1, 2007

By Young C. Kim, William C. Cassun

A proper economic analysis of pit slope design must reflect the trade-off between the benefits and the increased risk of slope failure inherent in steeper slope angles. This paper describes the results of a case study in which a newly developed probabilistic economic analysis procedure was applied to the selection of a pit slope design at a large porphyry copper mine in the southwestern U.S. The paper also demonstrates the availability of the required data such as the probability of failure schedule and cost of failure models, under "real-life" conditions.

Jan 1, 1978

By W. R. Penney, J. M. Richardson, J. Y. Oldshue

Introduction The mining industry has for years underrated the value of mixing in mineral processing unit operations. In present-day operations where leaching is playing an ever increasing role in the total profit picture, the need for good mixing is becoming more obvious. The engineer in the research laboratory and in the operations is by necessity becoming more familiar with the concepts of mixing. This section is designed to provide the engineer with mixing data and correlations sufficient to assist in the general planning of simple mixing systems.

Jan 1, 1985

By W. L. Dalmijn, J. M. Versteegen

During the production of silicon carbide, a byproduct is generated that contains a mixture of crystalline and amorphous silicon carbide. Utilizing the difference in density, shape, and surface properties of the crystalline and amorphous silicon carbide, separation tests were carried out with gravity concentration. The processing of the coarse fraction of the silicon carbide mixture by jigs resulted in a high grade crystalline SiC concentrate with the desired specifications. The separation was largely influenced by the shape factor. A jig with a newly designed hydraulic drive was used to carry out the test program.

Jan 1, 1991

By K. Shoji, R. Hogg, L. G. Austin

The flow of dry powders through continuous ball mills has been investigated. Based on a physical model of the system, expressions have been derived which relate the holdup of material in the mill and its variation along the length of the mill to the mill dimensions, speed of rotation, material feed rate, and the mill discharge geometry. Experimental results obtained in a small (4 in.) mill using 3/8-in. steel balls and a feed of silicon carbide particles are in good agreement with the prediction of the model.

Jan 1, 1976

By Ryan Lemmon

Belt turnovers are commonly used in conveyors to rotate the belt so that the clean side of the belt contacts the return idlers. The belt turnover length has traditionally been sized on only the twisting stresses. However, belt turnovers are also subjected to bending stresses due to the weight of the belt. Although bending stresses have in the past been ignored, these stresses are significant and should not be neglected. This paper quantifies and presents a method for calculated twisting and bending stresses and also the belt sag.

Jan 1, 2002

By J. van der Walt

In hot deep mines the ventilation and refrigeration requirements are determined primarily by the magnitude of the various sources of heat, and where in the mine they arise. Refrigeration is expensive, and in order to ensure that it is utilized effectively and at the lowest possible operating costs it is important that careful attention be given to the selection of plant, and how the cooling is to be distributed. The paper outlines the essential features of the highly effective strategy that has evolved in recent years in cooling deep mines in South Africa.

Jan 1, 1980

By Neil Hepworth

Neves Corvo Mine employs four mining and four backfill methods, including paste fill. The paper shows how the strength requirement for backfill in primary stopes was calculated and the relationship between laboratory strength and in situ strength requirement. The liquefaction of paste in secondary stopes is discussed with methods to determine the liquefaction potential. It was found from laboratory tests and the preliminary results of the underground trial, that the liquefaction potential of the paste is low at 2% and is high at 0.5% cement. The results to date are inconclusive regarding 1% cement.

Jan 1, 2001

By N. R. Paterson, D. A. MacFadyen

A late-1980 airborne EM/magnetic method test over the State Line kimberlite area of Colorado-Wyoming shows weak but recognizable anomalous responses to the known pipes. The magnetic survey indicates the presence of several shallow subsurface bodies adjacent to the known kimberlites, which are interpreted as possible blind diatremes. The survey data, in profile and contoured map form, has been correlated with geological map information available at the time. It can serve as the basis for reexamining kimberlite distribution in the area, taking into account geological findings during the recent work on known bodies.

Jan 1, 1987

By Patrick J. Doig

The NS9 Drop Shaft contract formed part of the Waste Pollution Abatement Program (WPAP) conducted by the Milwaukee Metropolitan Sewerage District (MMSD). The contract involved the construction of two shafts, a deaeration chamber and connecting tunnel, and ancillary facilities. Portions of the construction were located in saturated overburden where dewatering was prohibited. Ground freezing was utilized for temporary support of the excavation. This paper concentrates on the freezing system and the excavation of frozen ground, with particular emphasis on the use of mechanical cutting equipment, including a raiseborer and a roadheader.

Jan 1, 1991

By Paul-Emile Mercier

LOADING efficiency depends on cycle capacity of the loader, conditions of the mine, and mine organization. Cost of operation is the final criterion. Two types of loaders are analyzed-the boom shovel and the tractor-excavator. Studies were made in an open pit at Kimberley, Nev., where shovels are the production units and the tractor- excavator is a clean-up loader. The report deals mainly with the analysis of cycle and output. Problems of pit organization are not acute. (Other studies included in the original report and omitted here covered tractor-excavator application underground.)

Jan 4, 1957

By Dale Ross, Bill Clements, Jim Spanos

Current world conditions are forcing the search for "green" energy technology in every aspect of our daily lives. Finding alternatives to petroleum fuels seems to be at the top of the list. The search for the "perfect" alternative is something like the never ending quest of the perpetual motion machine. Unfortunately, the laws of physics prevent us from getting something for nothing, and Murphy's Law normally gives us nothing for a lot of something. Regardless of Murphy, the quest goes on, and in our industry cheaper ANFO seems to be the popular subject.

Jan 1, 2012

TO THE BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN: Submitted herewith are the report of the Treasurer for the year 1945 and reports for the same year of the following standing committees: Membership, Admissions, Papers and Publications, Mining and ' Metallurgy (Magazine), and Library. To these reports you are referred for additional details. Membership Membership, counting all categories other than Student Associateship, continues the upward trend of the last 10 years, reaching a total, as shown in Table 1, of 12,081. The net gain of 406 would

Jan 1, 1944

By T. Hall, R. Ferris

Waterjets and diamond wire saws have raised the productivity and lowered the cost in dimensional granite quarries. While the cost of diamond wire sawing is substantially lower than waterjet, the judicial use of the waterjet can simplify and improve the overall operating efficiency and predictability. Granite is the hardest commercial stone and only the gem-stones garnet and diamonds are harder. The introduction of industrial diamonds has made it possible to quarry and process granite at costs equal to or less than other natural stones – making granite, with its superior properties, the best value available.

Jan 1, 2004

By A. G. Starliper, H. Kenworthy, A. Ollar

Vapor pressure determinations were made on synthesized germanium sulfides. Germanium and cadmium were removed from sphalerite concentrates by fuming. The fume was retreated to separate some of the cadmium from the germanium and, at the same time, upgrade the germanium to more than 5 pet content. MANY sphalerite concentrates contain certain impurities which have economic value as byproducts. These may include the volatile sulfides of germanium, cadmium, and lead. The objectives of the research reported in this paper were to study the fundamental volatility characteristics of germanium sulfides, to increase the recoveries of ger-

Jan 1, 1957

By G. Lyman

The cross-belt sampler is a device that is very widely used even though it has not been ratified by the Standards associations. This paper is concerned with the bias testing of two cross-belt sampler designs against stopped belt samples and a cross-stream cutter at the belt end. The bias analysis is carried out using size distribution as the analyte and conventional t-testing and the Hotelling T squared test, which are compared for their effectiveness. The paper considers the issue of detectable bias and the statistical planning of bias tests.

Jan 1, 2009