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By William M. Wallace

Mr. Chairman and Gentlemen: The subject, "Shake It for Results," may or may not suggest just what is to be shaken, or just what results are to be obtained. I can assure you that if you are thinking about anything outside the realm of pure mining application you have come to the wrong meeting, and if this be the case, you have come to hear a subject discussed that I am not prepared to undertake-at the moment, at least. At the very beginning of time, results were definitely obtained by shaking. If you will recall, Eve shook a certain tree of forbidden fruit-need I recount to you the results that were, and are still, being credited to that bit of engineering? To get closer to the subject at hand, it is the intent of this paper to touch generally on the shaking, principally the vibratory shaking, of materials on a piece, or pieces, of perforated metal or screen cloth. Through the evolution of such a motion we find that great strides have been made toward a highly efficient "operation which is an essential factor in the mining world of today. The object of the shaking motion is to more efficiently separate one size material from another, according to the openings in the screening medium over which it is passed. Sizing is an important operation in every ore dressing, coal prepara¬tion or other mineral-preparing plant for reducing the product to a form more concentrated or more convenient for utilization than that in which it was mined. In coal preparation, market requirements, convenience, custom, and efficiency in combustion necessitate grading mined coal by sizes. All ore-dressing or coal preparation plants therefore must have what is called screening, sizing, or grading apparatus.

Jan 1, 1941

By G. M. Rao, P. N. Deo

Graphite is soft and easily floatable but it is quite difficult to obtain high purity concentrate at coarse sizes. Chemical treatment can produce high grade concentrate but it is an expensive process. Graphite containing plus 96% fixed carbon (FC) with coarse flakes commands high price in international market. Such graphite concentrate containing plus 96% FC was produced in Indian Bureau of Mines (IBM) by using newly developed reagent (mixture of different hydrocarbons and terpenes, IBM/D7) instead of commonly used frothers viz. pine oil, MIBC, kerosine etc. and regrinding in a special type of mill with special grinding media instead of grinding in a conventional ball/ rod mill followed by cleaning. Both the new reagent (frother) and special grinding media are inexpensive and readily available. The process is under patenting. This paper focuses application of this new grinding methodology for flake size protection, and the new reagent for selective flotation of high purity graphite.

Jan 1, 1995

Roger A. Markle was sworn in as director of the US Bureau of Mines on September 27, 1978, ending a 20-month period during which the Bureau was without a leader. Some Bureau observers wondered out loud if this delay was a signal that Interior was slowly pulling the rug out from under the agency. When Markle was finally tapped for the director's position-coal industry executive to lead an agency that had been stripped of its fossil fuel R&D functions as well as its safety and health enforcement role--the speculation was fast and furious: One camp had it that Markle was brought in to phase out the Bureau; others said that Markle's directive was to revitalize the organization by charting a new Bureau course. In March, with the proposed Department of Natural Resources making headlines, ME went to Washington to interview Markle about his first six months as director and the goals he has set for the Bureau's future.

Jan 4, 1979

By Brian F. Osborne

A continuous on-line particle-size analysis system for solid/liquid suspensions is described. The basic sensor utilizes a centrifugal principle to separate particles according to size, the resultant separation being measured by means of beta-ray attenuation. Results obtained when analyzing a variety of materials at sizes from 65 mesh (210 µ) to 20 w are discussed in detail. Accuracies better than 2% are demonstrated. The effects of particle specific gravity, and mixtures of materials of diverse specific gravities, are discussed from both a practical and a theoretical viewpoint. It is demonstrated that particle specific gravity has a minimal effect on the size reading obtained. This renders the instrument suitable for handling materials where the ratio of light to heavy component may change. The design of the first commercial installation of this instrument is described in detail. This installation will be capable of analyzing three streams in sequence, measurement at three particle sizes being effected on each stream.

Jan 1, 1975

By Ian Longson, Darron W. Dixon

This paper describes the results of an investigation into the application of a statistical method for the prediction of general air-body methane concentration in longwall coal districts. An important and necessary part of the research was the acquisition of representative monitored mine environmental and coal production data. The monitored data was used to build time series models of general air body methane concentration, air velocity, barometric pressure, coal production and methane drainage variables of differing timescales according to the Box-Jenkins method of time series analysis. The univariate models were used to identify causal relationships between methane concentration and its explanatory variables. Coal production was found to be the dominant variable in the determination of the quantity of methane emitted and where appropriate, multivariate time series models were built in which expressions for methane concentration in terms of coal production were obtained. Finally, forecasts of methane concentration values were generated from the multivariate models to determine their forecasting capabilities.

Jan 1, 1993

By W. Gong

Their outstanding thermal stability and high energy product make Sm(Co,Fe,Cu,Zr),-type alloys attractive for advanced applications. The near net-shape production of Sm(Co,Fe,Cu,Zr), bonded magnets make them potentially superior to any magnets made by sintering. Although pioneering work done by Shimoda et al. and other investigators provide insights on the proper compositions and process control of this alloy system, additional work is still necessary to improve our understanding of alloy behavior at various processing stages and to increase the production yield during powder processing. In this paper we report on the development of anisotropic Sm(Co,Fe,Cu,Zr), alloy powders for the bonded magnet application. Our focus is on the development of a moderate coercivity powder requiring a relatively low magnetizing field to charge the magnets to their optimum Br, Hci and BHmax. The magnetic properties are related to the evolution of the microstructure at various processing stages and the average particle size and size distribution of powders.

Jan 1, 1997

By Harada M, Katsuta S

In order to shorten the time taken to com- plete shield tunnel excavation work, reduce labor costs and to improve safety, an automatic assembly robot system for the segments used has been developed. It was developed in the three years from 1982 until 1984. An experimental assembly system for concrete segments (outer diameter:.3.55m) has been thoroughly tested to confirm that these segments can be fed and assembled automatically (Fig. 1, 2). This report outlines the robot which will be put into practical use in the near future. The robot senses the position of already assem- bled segments by means of position sensors, controls the position and the attitude of the segment to be assembled to allow bolt hole positioning, and completes the automatic assembly of a se;nent by automatically tighten- ing bolts. The six segments which make up one ring can be automatically assembled in about 25 minutes.

Jan 1, 1987

By Rashleigh C

The selection and application of an effect- ive firing system first require a clear under- standing of the initiating abilities of the com- ponents in such systems. The conditions under which charges can be prematurely initiated by a detonating cord downline must be appreciated. This is a principal consideration in the design of a successful downline/'Anodet'/primer assembly. The advantages and limitations of an electric and several non-electric initiating systems are explained. The factors which in- fluenced selection of the two most suitable systems for use at Isa Mine (viz. downline/ 'Anodet'/primer assemblies and the reinforced long-lead 'Anodet'-type delay system) are dis- cussed. Blasts are detailed in which each of these has been applied. The initiating design for a hypothetical 2 x 106 tonne blast using electric short delay detonators and multi-channel exploders is presented. In this design, charges in remote blastholes are activated after the detonation of earlier firing charges by protecting the firing lines with sandbags.

Jan 1, 1978

By James D. Navratil

Neutral bifunctional organophosphorus solvent extractants (such as carbamoylmethylphosphonates and carbamoylmethylphosphine oxides) strongly extract lanthanides and actinides and do not extract more than 40 other elements from mineral acids. Because of their excellent properties they have been found useful for F-element recovery and purification processes. A brief overview of the lanthanide and actinide extraction chemistry of these reagents will be given.

Jan 1, 1990

By Charles M. Wilk

"Mass stabilization (MS) is a ground improvement technique that can prepare areas of low bearing strength soil for subsequent infrastructure development. The technique involves mixing binding agents such as portland cement, fly ash, slag, or lime into the subject soil while the soil remains in-place (insitu). The binders “cement” the soil grains together to form a cement modified soil or a soil cement. The MS-treated area now has improved bearing capacity to support infrastructure or to prevent movement of the material such as landslides.The same insitu soil mixing technique can be used to address contaminated areas. Binders or reagents are mixed into soil. The treatment protects human health and the environment by immobilizing hazardous constituents within the treated material. When used for the purpose of environmental remediation the technology is called Insitu Solidification/Stabilization (ISS).Both Mass Stabilization and ISS treatments require laboratory studies to develop a mix design of soil and binder(s) that produce the desired physical and/or chemical properties. The mix design is then transferred into the field. Successful MS and ISS treatments rely on reproduction at full-scale of the mix design and the thorough mixing attained at laboratory scale. Fifty to 70% of the cost of a MS or ISS project is in the cost of the binding agent that is to be mixed into the subject soil. Under-dosing, overdosing, non-thorough mixing, and mixing in the wrong areas all create cost over-runs.This paper will discuss recent innovations in mass stabilization systems that improve the cost effectiveness of the treatment technology. Specialized equipment can impart greater mixing shear thus improving the thoroughness of mixing. Dry powder pressure feeders can conserve the “drying capacity” of binder resulting in higher strengths at lower binder dosages. Global Positioning System (GPS)-based systems can guide the mixing operator for complete mixing coverage. An integrated tracking and feeding system can record that proper dosing and mixing was accomplished and generate construction QA/QC reports for the client.INTRODUCTIONNew or expanding infrastructure projects may encounter areas of low bearing capacity soil or areas where marginal materials such as waste, dredged material, or sediment have been placed. Mass stabilization is a geotechnical method that can be used to improve the bearing capacity or stiffness of soil. Mass stabilization involves mixing binding agents into soil subject to treatment while the soil remains in-place or insitu.Mass stabilization technique can also address contaminated soil therefore, the same technique can be used to attain both civil and environmental engineering goals. In this environmental application the technology is known as insitu solidification/stabilization (ISS). ISS protects human health and the environment by immobilizing hazardous constituents within the treated material."

Jan 1, 2015

By Otto F. Pfordte

In my paper on " The Refilling of Sulphides Obtaihed in the Lixiviation-Process with Hyposulphite Solutions " (Trans., xx., 37), I gave the outlines of a process for refining sulphides. In a subse-

Jan 1, 1893

By John B. Gayle

PRESENT flotation processes depend almost entirely on the buoyant properties of air bubbles to effect separations of mineral and gangue, but there is no convenient method for measuring aeration in flotation cells. Consequently the relation between aeration and cell performance has not been definitely established. In connection with a comparative study of kerosene and froth flotation processes, a modification of the displacement method' was developed in which air escaping from the cell surface is measured with a wet-test meter. The arrangement shown in Fig. 1 is satisfactory for use with a number of cells and is not critical, except that care must be taken to use connections and tubing large enough to avoid excessive back pressures. Attempts to use smaller tubing resulted in back pressures that caused displacement of the liquid level in the receiver, so that some air was lost around the sides, an occurrence readily visible when measurements were taken with only water passing through the cell. With the arrangement shown, the manometer indicated an average reading of about ½ -in. water pressure. No loss of air was evident.

Jan 7, 1958

By P. R. Sperry

A METHOD was recently devised to indicate two or more successive stages of the migration of grain boundaries in aluminum, and to record the direction of the migration. This technique was used for the study of the various types of boundary migration occurring in high purity aluminum.' The method employs alternate annealing and electrolytic etching treatments, repeated as many times as desired. All successive sets of grain boun- dary positions revealed by the various etches appear superimposed on each other. The last etch is designed to leave an oxide film on the surface which is optically anisotropic. The orientation of the oxide film at each point is determined by the orientation of the underlying aluminum grain. When viewed with polarized light using crossed nicols and a Biot-Klein quartz plate, grains with differing orientations appear in different colors, as described by Hone and Pearson.' The last boundary positions are revealed by these color differences. The first step of the process is to obtain a desired starting grain size by annealing, for example, if high

Jan 1, 1951

By F. F. Peng, D. C. Yang, G. Yanief, E. H. Cho

This study deals with carrier flotation of cerium dioxide, a surrogate of plutonium oxide, which is the major contaminant at the Nevada Test Site (NTS). The objective of this study was to determine the feasibility of using carrier flotation for remediation of the site. In this study, a - 200-mesh fraction of pure cerium dioxide was used. Oleic acid was used as the collector, while calcium carbonate was used as the carrier. Mechanical-cell tests were conducted to float the surrogate from a mixture containing uncontaminated NTS soil, both in the absence and presence of the carrier. It was found that the addition of the carrier drastically enhanced the flotation recovery of cerium dioxide. The flotation recovery of the surrogate increased from 34% to 65% by adding only 0.5% calcium carbonate (-150 mesh). The recovery further increased to 95% by adding 10% calcium carbonate. The flotation method utilizing a carrier of calcium carbonate seems to have a high potential for the remediation of the soil contaminated with radionuclides at the NTS.

Jan 1, 1998

By R. W. Kobler, D. A. Dahlstrom

Since the development of the pelletizing process in the fifties for relatively high purity pellets from low grade taconites, there have been several distinctive changes in filter construction for the dewatering step preceding balling. In the original large pilot plant run by Reserve Mining Co. in Babbitt, MN, the disk type filter employing agitation (Agidisc filter) was selected as the most economical. Size was limited to 2.1 m (6 ft, 9 in.) in diameter. The second generation occurred in the sixties with a jump to 2.70 m (8 ft, 10 in.) in diameter to reduce capital costs per annual ton of pellet. In the early seventies, the third generation was the steam drying disk filter which became necessary to achieve balling moistures with specific surface areas of 2200 cm2/g to as high as 3800 cm2/g caused by finer grinding to obtain higher purities. Finally, the fourth generation has recently been developed to reduce maintenance costs and further improve hydraulics to ensure minimum moisture contents.

Jan 1, 1980

Improve the safety and reduce the cost of longwall entry support. Approach Replace the conventional wood cribbing with stronger, non-rotting and lower cost cribbing made of steel-fiber-reinforced (SFR) concrete. How It Works Conventional concrete can suddenly fail under excessive compression loads, but adding steel fibers to the concrete, before it is mixed with water, changes the failure mode to a gradual and controlled failure characteristic similar to wood. A system for making SFR concrete crib blocks was designed and developed (or use in constructing walls and cribs to support coal mine roofs. The SFR concrete cribbing is stronger and stiffer than wood, and avoids wood's disadvantages of: flammability, deterioration under chemical or bacteriological attack, methane generation, and relatively high cost. Use of SFR concrete also allows freer movement of miners, equipment, and ventilation air, because much less volume of SFR concrete is required than wood for a given amount of support, and because the roof-to-floor closure is greatly reduced by the stiffer supports.

Jan 1, 1981

The establishment of vegetation onto open cut mine spoil is dependant on the nature of the soil and rock strata of the overburden. Experience has shown that in the Bowen Basin of Central Queensland the nature of the minespoil changes considerably as subsequent and deeper mining strips intercept changing rock strata. The different mixes of strata at the surface of reshaped spoilpiles can produce variable response in the sown vegetation cover. It is usual that land features of mine sites are known in detail and are depicted on mine or locality maps. Subsurface strata and lithology descriptions are available and are used for planning of open cut mining operations. Surface and subsurface data can also be used to estimate the intrinsic nature of overburden through the use of fence diagrams. Lithology at points along a mined strip can be obtained and used to describe overburden. Indications are that correlations exist between salinity of overburden components and the response of vegetation. The developed procedure thus becomes a useful tool for the prediction of revegetation Practices.

Jan 1, 1987

By Sadough vanini Ali

Charpy impact energy of functionally graded steels produced by electroslag remelting in crack divider configuration has been modeled in various strain rates. It has been well known that majority of materials indicate different behaviors under different strain rates and temperatures. Therefore, modifying the elastic-plastic model considering the effects of strain rates and temperature gives us an acceptable prediction of these composites behaviors in impact test. In this investigation, graded steel was divided in to several layers in which the layers have the same strains under the impact. Constitutive equation describing the flow stress variations as a function of strain rates and temperatures, have been used to express the stressstrain behavior of layers. The parameter values of constitutive equation determined for all the layers via using the boundary conditions based on composite graded behaviors which were the characterized ferrite, austenite, bainite and martensitte phases. Consequently by applying the rule of phase mixtures and ascribing the impact energy of each layer to the area of stress-strain curve of the same layer, the whole impact energy of composite is the sum of layers impact energy with considering the layers volume fraction.

Oct 1, 2011

By James W. Mahar

The following paper summarizes our observations on building response to mine subsidence and techniques for mitigation of building damage. The subsidence cases are located in Illinois. The general description of the geologic and mine conditions are primarily for those sites. Data on building response and mitigation measures were collected under grants supported by the Abandoned Mined Lands Reclamation Council (AMLRC) of Illinois and the U. S. Bureau of Mines, in Twin Cities, Minnesota. Case histories include pit and sag subsidence primarily beneath abandoned room and pillar mines. The majority of the paper deals with structures affected by sag subsidence. Most of the structures are one and two story homes. The first section of the paper summarizes the typical geologic and mining conditions at the sites. Building response to pit and sag subsidence follows the first section. Emphasis is placed on the behavior of concrete and masonry foundations, and wood frame and masonry superstructures. The third section describes mitigation techniques used to prevent or minimize building damage. A summary of the observations and critical parameters is given at the end of the paper.

Jan 1, 1982

By David Muir, Slobodanka Vukcevic

Gold is commonly associated with copper minerals, particu­larly in the more geologically recent rocks of Northern Australia, Chile and the Pacific Rim. Traditionally, oxidised copper-gold ores are selectively mined and processed for gold by cyanidation, ensuring that levels of reactive copper in the ore are kept low to minimise cyanide consumption; whilst sulphide copper-gold ores are floated and gold is ultimately recovered as the by-product from copper smelting and refining (La Brooy, 1992). Very few process­ing options exist for treating copper ores which cannot be selec­tively mined or floated, and for treating floation tailings which often contain significant gold (Muir et.al.,1989). The ammonia-cyanide leach system stands out as a unique method of selectively extracting gold without copper using economic levels of cyanide (1-2 kg/t NaCN) and ammonia (1-5 kg/t). Although first patented in 1904, it proved difficult to control and predict per formance with different ores. However, recent research and development in Western Australia by Ruane (1991), Hayes and Corrans (1992), La Brooy et.al.(1991), Muir et.al.(1993), Muir and La Brooy (1993), has led to an under­standing of the mechanism, and the commercialisation of the process at the Paris Dump (W.A.), Akjoujt (Mauritania), and in the Eastern Transvaal (Laxen,1994). Efforts are now underway to pilot and develop a tailings treatment plant at Telfer following successful laboratory trials. To date, process optimisation has relied on trial and error and large numbers of tests covering a range of conditions. Thus the results are specific to the ore. At Murdoch University, process optimisation is now focused on measuring and control­ ling Eh, pH, NH3 [Cu(II)], and Cu-CN species at the optimum levels identified from the recent mechanistic studies. In this way, the optimum composition required to process any ore should be readily established and maintained.

Jan 1, 1995