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By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different field and regions as made by the Bureau of Mines Hempel method of analysis.4/ Several of these reports include analyses off crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By James Douglas

In discussing the waste upon which hinges, or is supposed to hinge, so largely the preservation of our national resources, the conclusions reached would be more reliable if actual experience were consulted, and fewer deductions were drawn from general statements, which are often the product of the imagination. It cannot be questioned that the value of by-products has .not been sufficiently appreciated by us, and that our tardiness in recovering the useful ingredients of the escaping gas of our coke-ovens is one of the most glaring instances of shortcoming in that direction. And yet even for that sin there is some palliation in the immature condition of affiliated industries. I presume that it is admitted, without argument, that, except under very exceptional conditions, all the elements cannot be recovered from most of the ores or natural products which we treat. While it is a shame that the by-products from our coke-ovens should be dissipated, Edward W. Parker's report to the U. S. Geological Survey for 19061 supplies a fairly good excuse in justification of this appalling waste. He says (pp. 773 to 774.): " What has been already commented on in previous reports about the slowness of manufacturers to change from the better known but wasteful beehive practice to the by-product recovery method of coke manufacture is particularly emphasized in the statistics presented in this chapter. For it would appear from the table following that the construction of by-product ovens had about come to a standstill, especially when the records for the preceding five years are taken into consideration. At the close of 1901, when there were only 1,165 by-product ovens completed in the United States, there were 1,533 in course of construction, 498 of which were completed during the following year. At the close of 1902, 1,346 retort ovens were building, 293 of which were added to the completed plants in 1903. At the close of 1903, 1,335 new ovens were building and 954 of these

Jan 1, 1910

By S Dykes, R J. McCarthy, B Klein

There is growing interest in the mining industry on the application of ore sorting. While many are familiar with particle sorting, including the limitations that technology presents (e.g. throughput), bulk sorting, with its higher throughput potential, is less understood. Despite the potential to sort at higher throughputs, few operations have adopted bulk sorting processes, certainly not at large scale. It is suggested that the inability to reliably predict outcomes from bulk sorting may be limiting its adoption in mining projects. Consequently, an evaluation approach for bulk ore sorting has been developed such that mass pulls and grade upgrades can be predicted in the context of a mining study. The approach allows for evaluation of drill core assays and application of the consequently derived heterogeneity relationships to the block model for estimation of sorting outcomes. These processes were applied to conveyor-based bulk sorting for the CuMo project in Idaho, USA and are described in this paper.

Nov 10, 2020

By Liangju He, Peixuan Ouyang, Peijie Li

Single-pulse laser ablation of aluminum and titanium alloys under glass confinement is investigated. Processing parameters such as laser intensity and gap width between targets and glass are varied. Surface morphologies and crater profiles of the alloys after laser ablation are studied by SEM and white-light interferometric microscope, respectively. The effects of gap width and laser intensity on surface morphologies and crater profiles of targets are systematically analyzed. In addition, the generation of porous surface structures in Ti target is regarded as the result of phase explosion in the molten surface layer of targets and the thermodynamic condition in our experiment for phase explosion is evaluated.

Jan 1, 2016

By C. R. Woodcock, J. S. Mason

In almost any situation where particulate or granular bulk solids have to be conveyed, whether for a distance of a few metres or for many hundreds of metres, a pneumatic conveying system may be considered. Conveying by pipeline is convenient and clean, but running costs may be substantial because of the heavy air consumption and the trend has therefore been towards dense-phase transport in which the ratio of conveyed solids to conveying air is kept high. This paper concentrates on air-float conveying, which can be regarded as an extreme form of dense-phase conveying where the bulk solid is fluidised in a channel and then caused to flow, either by inclining the channel or creating a pressure gradient along 'it. Various designs of air-float conveyor for upward, horizontal and down- ward transport of powders are discussed, with special emphasis on the latter case. In situations where a continuous downward slope can be provided, the combination of air-fluidisation and gravity flow results in a conveying system that, for many kinds of bulk particulate solid, would be hard to better in terms of convenience, reliability and economy. The paper is concluded with a discussion of design features and performance of practical air-gravity conveyors, involving the handling of various bulk particulate solids, both in research and in full-scale industria1 applications.

Jan 1, 1980

By L. S. Castleman, R. K. Hotzler

We are currently studying the effects on recrys-tallization of impurities diffused into dispersion-hardened alloys. Our interest in this phenomenon was originally aroused by the observation that the recrystallization temperature range of tungsten "doped" with alumina and silica, or with thoria, is lowered drastically if nickel is plated onto the tungsten prior to heat treatment.' In this note, we report a similar effect that sulfur has on the recrystallization behavior of thoriated nickel. The experimental procedure for this exploratory phase of the investigation has consisted simply in heating commercially obtained stress-relieved samples of thoriated nickel for varying temperatures and times in sealed capsules containing air and small quantities of sulfur. The samples contain 2.4 vol pct thoria and initially less than 18 ppm S by weight; they are prepared either from 0.5-in.-ciiam rod stock or from 0.092-in. sheet and are in the "as-received" (stress-relieved) condition prior to exposure. In an atmosphere free of sulfur, such samples do not show evidence of recrystallization after being annealed for 1 hr at a temperature of 2500°F (1372C).2 The photomicrograph in Fig. 1 shows the microstructure of one of our samples annealed for 75 hr at 1000° C (1832°F) in a sulfur-free capsule. The grain structure is hardly evident (if at all) at 465 times magnification. In contrast, the photomicrograph of Fig. 2 shows the recrystallization that has taken place in a sample exposed to sulfur for 5 hr at 1000°C (1832°F). A nickel sulfide phase is visible at the grain boundaries of the light-appearing grains. We have also observed recrystallization to occur in a sample annealed at 600°C (1112°F) for 25 hr. This temperature is below the 637°C (1178°F) eutectic in the Ni-S system. In the latter case, no nickel sulfide phase is evident in the microstructure. Moreover, we have noticed the occur-

Jan 1, 1969

By Qiang Zhang

Hybrid composites are fabricated by adding two reinforcements into matrix materials so that the expected excellent properties can be achieved through the combined advantages of short fibers, and different size particles (micron or submicron), which provide a high degree of design freedom. In this paper, hybrid preforms were produced with the different size reinforcement of the Al2O3 particles and short fibers. The Al-Si alloy-based hybrid composites were fabricated by preform-squeezing casting route. The structure and performance of composite materials were studied with the Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). The results show that the reinforcements, both particles and fibers, distribute homogeneously in the matrix materials, and the properties of composites are found to improve in comparison with the matrix Al-Si alloy.

Jan 1, 2009

By R. A. Thomas, C. D. Litton

"The objective of this study was to develop a laboratory-scale method to rank the ignition and fire hazards of commonly used underground mine materials and to eliminate the need for expensive large-scale tests that are currently being used. A radiant panel apparatus was used to determine the relevant thermal characteristics of the materials: time to ignition, critical heat flux for ignition, heat of gasification, and mass loss rate. Three thermal parameters, TRP, TP1, and TP4, were derived from the data, then were developed and subsequently used to rank the combined ignition and fire hazards of the combustible materials from low hazard to high hazard. The results compared favorably with thermal and ignition hazards of similar materials reported in the literature and represent a simpler approach to quantifying these combustible hazards. INTRODUCTION The potential fire hazard from combustible mine materials is a major concern that can impact the safety of mine workers. Combustible materials tend to be solids and within this category there exist degrees of flammability and fire resistance. These materials may be readily ignitable or they may be able to withstand high temperatures and high heat fluxes. Presently, no simple methodology exists to assess these possible fire behaviors and quantify the resultant fire hazards. Thus, better knowledge of the thermal properties and chemical characteristics of combustible materials is of great importance to the safety of mine workers. Tewarson [1994] developed a methodology which he subsequently used to evaluate the ignition and fire resistant properties of combustible mine materials, but these efforts are more than 20 years old, and do not include many of the new materials used in mines today. The standard practice that has evolved for a combustible material to be approved by the Mine Safety and Health Administration for use in underground coal mines is to conduct extensive and costly large-scale experiments on each new material that is used in a particular mine operation. Results of such tests provide pass/fail answers to the questions of a material’s flammability or fire resistance, yet they provide little, if any, information that will lead to a better understanding of the basic mechanisms involved. Therefore, there is a need to quantify material flammability properties and to develop a methodology to rank the ignition and fire hazards of commonly used underground mine materials. During the heating and ignition stages of combustible materials, properties such as smolder susceptibility, minimum surface temperature for ignition, thermal conductivity, heat capacity, density, and heat of gasification are known to be important [Apte, 2006]. During the flaming stage, additional parameters, such as the heat of combustion, heat release rate, flame spread rate, yields of soot/smoke, and toxic gas production become more important as the flame is sustained and spreads. In very general terms, the heat flux incident on the surface of a solid combustible not only controls the rate of temperature increase of the local fuel surfaces, resulting in expulsion of fuel vapors that sustain the flaming process, but also the heating of other combustible surfaces that subsequently ignite and spread flame."

Jan 1, 2015

By Thomas M. Drown

ZING is, as is well known, very brittle at a temperature of about 210' C. (410' F.), and may then be readily pulverized in a mortar. By sifting it may be obtained of uniform grain. I have been accustomed to prepare products passing through 40, 60, and 80-mesh sieves, and also by bolting through a fine handkerchief. The principal analytical uses to which I have hitherto applied this material are to the reduction of iron directly from the ore by heating it with the pulverized zinc, and the reduction of ferric to ferrous compounds in solution. In the first case the pulverized ore, 0.5 gram or less, is intimately mixed with about ten times its weight of the pulverized zinc (the finer the zinc the better), in a porcelain crucible, and this mixture is covered with about the same amount of zinc. The crncible is then heated at the top of the flame of a Bunsen bhrner, at a dull red heat, for about ten minutes. The crucible should not be covered. When cool, the crucible, with its contents, is placed in a flask treated with hot dilute sulphuric acid, and brought quickly to a boil. The zinc and reduced iron are dissolved in a few minutes and the flask is then tightly corked and allowed to cool. When cool, the iron is directly titrated by potassium permanganate.

Jan 1, 1879

By R. W. Smith

Living and killed organisms, particularly microorganisms, and extracellular products derived from the organisms are increasingly finding use in minerals engineering. Goals include both enhancement of mineral processing/11.ydrometallurgica,l operations and remediation of mineral industry wastes. Some of the applications, such as biologically assisted leaching of ?sulfide ores and bioxidation of refractory gold ores, are well established commercial ?processes used around the world. Others, such as the use. of organisms for the removal of heavy metal ions from dilute aqueous streams, are nearing commercial application. Many other uses of microorganisms and. their derivatives are potentially possible. These include use of microorganisms in flocculation or flotation of minerals., remediation of organics potentially discharged from mineral engineering operations, degradation of cyanide, the recovery of bitumen from heavy oil reservoirs and tar sands and the solubilisation of lignites and low rank coals. In order to fully exploit these many possible uses of organisms and their derivatives, extensive fundamental .and .applied research work exploring the fundamentals, potential and practicality of the various possible uses of microorganisms in mineral engineering should be vigorously pursued. ?

Jan 1, 1991

"The reduction works of the Boston & Montana Reduction department, near the north end of this dam is one of the reduction plants belonging to the Anaconda Copper Mining Company, the other being at Anaconda. These works employ about 1,100 men and have a capacity of about 3,800 tons of crude ore per day. This plant is now being remodeled to embody results of experiments and investigations which have been made with a view to more economic.al treatment of ores. A brief description of the plant as it will be after the remodelling is as follows:Concentrator Department: Consists of six units or sections, each section treating from 550 to 600 tons of crude ore per day. This department is not being. remodelled at the present time. A concentrating process, however, has been developed and partially installed in the old mill, and an experimental section embodying this concentration process has also been installed at the concentrator at Anaconda."

Jan 1, 1913

By Jorge D. Vier, Raúl B. Rebak, Alicia E. Ares, Natalia S. Zadorozne

Recent worldwide demand has driven nickel and molybdenum prices to record high values. Alloys containing significant amounts of nickel and molybde- num, such as the austenitic and duplex grades, have experienced significant price increases and some spot shortages have resulted in some regions. With low or no nickel content and reasonable molybdenum content, super-ferritic stainless steels are now proving to be the most cost effective corrosion resistant materials. The electrochemical behavior APMT® (Fe–21Cr–5Al–3Mo–0.04C) and 4C54® (Fe–26.5Cr–0.8Mn–0.5Si) super-ferritic stainless steel in NaCl solutions has been studied using open circuit potential measurements, potentiodynamic polarization curves, and electrochemical impedance spectroscopy. The aim is to compare the behavior of these materials with austenitic stainless steel alloy 316 (Fe–18Cr–10Ni– 2.5Mo). The results indicate that the APMT alloy presents a better performance than the AISI 316 stainless steel, while 4C54® does not, especially at anodic potentials. The good behavior of APMT® may be attributed to Al and Mo content in its composition.

Mar 1, 2017

By Peter Faust, Peter Hubbard, Kenichi Soga

The European Federation of Foundation Contractors (EFFC) and The Deep Foundations Institute (DFI) have set up a task group to compile a Guide for Working Platforms. The first edition of this Guide has been published in January 2020. The aim of the Guide is to provide reliable methods for design, testing and verification of working platforms for construction equipment, especially in the deep foundation industry where track loads can be excessive due to the nature of its operations. The Guide has identified areas where knowledge is limited. Actual track pressure and its distribution along the length of the tracks is still not well researched. Current recommendation provided in EN 16228-1 are believed to be overly simplified and may lead to conservative requirements for working platform thickness. This paper presents results of a series of field tests where the actual track pressure of a large drilling rig during operation was measured in real time together with the deformation of the working platform. Embedded, distributed fiber optic sensing (DFOS) at different depths throughout the platform allowed for a three-dimensional evaluation of the platform deformation throughout the entire operation. Results will help to develop more reliable recommendations for future safety requirements of working platforms for deep foundation equipment.

May 1, 2022

To inexpensively monitor the ventilating airflow anywhere in underground working places. The Approach: The Bureau has developed a small self-contained monitor which sounds an audible alarm and energizes a flashing lamp if air velocity decreases below normal. How It Works: The sensing element of this inexpensive monitor is a thermistor, which is self-heated by a constant-current electrical source. Airflow over the thermistor increases heat removal and lowers the thermistor temperature. Since the electrical resistance of a thermistor is a function of temperature change, the voltage across it varies with temperature, and, therefore, the air velocity. Changes in the voltage across the thermistor are amplified, and can be used to trigger the alarms.

Jan 1, 1975

By G. S. Rice

[This paper describes preliminary tests at the Bureau's Experimental Mine to determine, under conditions that may prevail ira bituminous coal-mine heading, how small a quantity of fire damp may bring coal-dust into suspension and ignite to it. The results show that the explosion of as little as 150 cubic feet of an explosive mixture of gas and air containing 9 per cent natural gas may start a disastrous explosion Of coal-dust. This is a very small volume, of gas, to cause such a result. Let us suppose that this amount of exclusive mixture, was at the face of an entry which was 10 feet wide and the face was overcut to a depth of 6 foot and an upper layer of coal 2 1/2 feet thick had been removed, the recess so made would save a volume of 150 cubic feet. Furthermore, only 13 cubic feet of pure methane is needed in this volume to produce this 9 per cent explosive mixture.]

Jan 1, 1930

By A. West, F. Mohammadi

Growing awareness of selenium bioaccumulation has resulted in selenium management becoming an important environmental issue for mining operations. Selen-IX™ is a novel ion exchange based technology developed by BioteQ to provide an effective solution for removing selenium oxyanions from mine impacted water to single-digit µg/L levels. The technology offers significant potential benefits when compared to incumbent biological treatment processes, including substantially reduced capital and operating costs and significantly reduced production of a selenium-containing sludge for final disposal. This paper reviews the key features of the Selen-IX™ process and presents the results of recent pilot testing on selenium impacted water.

Jan 1, 2014

By AIME

VERSATILITY is perhaps the outstanding characteristic of the subject of this sketch. He is author, golf-player, musician, public speaker, philatelist, German scholar, and has been a school teacher; but these are incidental. Oliver Ralston's professional forte might be described as beneficiating solid minerals and he has dealt in an important way with practically all of them. To this work he has brought a fertile mind stimulated by keen imagination but kept on the track by a sense of economic balance. An indication of his versatility is evidenced by his career with the Bureau of Mines, which he first joined in 1912, when the Bureau was just one year old. Except for two excursions into industry-Hooker Electro Chemical Co. (1917-20) and United Verde Copper Co. (1928 to 1935)-his entire professional career has been with the Bureau.

Jan 1, 1946

By M. Massinaei, M. R. Yarahmadi, S. Zeidabadi, M. Oliazadeh

"Although the majority of new flotation column installations continue to be for cleaning or recleaning, an increasing number of flotation projects are specifying columns for roughing or scavenging duties. NICICO has recently installed flotation columns operating in rougher, cleaner and re-cleaner circuits at three new copper concentrators; Miduk, Sungun and Sarcheshmeh. Miduk is probably one of the unique operations that use flotation columns in a rougher circuit. The Miduk rougher circuit comprises five CISA parallel columns. The rougher concentrate constitutes 88% of final concentrate and reports to concentrate thickener. The rougher tailings are scavenged with ten 50 m3 mechanical cells. The scavenger concentrate is then reground and cleaned in three 3.2 m columns in parallel. The cleaner tailings are scavenged in six 50 m37mechanical cells. The cleaner tailings along with the rougher scavenger constitute final tailings.In Sarcheshmeh, the cleaner concentrate is re-cleaned in a column. The column tailings are sent back to the cleaning circuit and the concentrate is reported to the concentrate thickener.This paper reviews performance details of the flotation columns utilized in rougher circuits at Miduk and compares their metallurgical performances in an industrial scale with columns at cleaning circuits for copper flotation. Practical limitations for applying the flotation columns in rougher circuits will be discussed in details.INTRODUCTIONThe use of flotation columns has grown rapidly since the first successful commercial application at Mines Gaspe, where columns were used in a cleaning circuit to float molybdenite. Early applications of columns were restricted to replacing or adding final cleaning stages in existing circuits. Columns can achieve superior cleaning as compared to conventional cells due to their ability to support a large froth depth and the use of water for washing froth. Wash water travels down through the froth and crosses the pulp/froth interface, replaces the entrained particles reporting to the froth from pulp and improve the concentrate grade."

Jan 1, 2011

By William Gleason

There was a time, not too long ago, when the most daunting challenges facing those in the mining and mineral processing industries could be solved through better technologies and better practices. But now the challenges that come from the actual acts of mining and processing are just part of the bigger picture. SME?s Colorado Section of the Mineral Processing Division (MPD) hosted its 63rd annual meeting at the Broadmoor Hotel in Colorado Springs, April 25-27 and, while the conference had its fair share or mineralolgy and processing presentations that were heavy on the technical side of things, this year?s conference was also focused on the issues of permitting, regulation compliance and legislative issues. The so-called ?softer? issues, that, if not addressed, can lead to very real and very hard challenges. Under the theme ?Mine your own business - permits, startups, expansions and resources,? even the most dedicated metallurgists were drawn into the discussions of politics and legislation, and how those issues affect their business. Fittingly, Colorado Mining Association (CMA) president Stuart Sanderson was honored with the Arthur C. Daman Lifetime Achievement Award. Sanderson, an outspoken proponent for the mining industry in Colorado and beyond, also presented the keynote address to the lunch crowd where he spoke about framing public opinion toward mining and the efforts of the CMA to move the public opinion dial in a direction more favorable to mining. Sanderson explained that Colorado, once a Republican stronghold, turned after 2002 and now is controlled by Democrats who are traditionally less supportive of the mining industry. Sanderson said the deciding factor in the power shift was money, as supporters of Democrats outspent Republicans in the most recent election cycles. CMA has done its part to keep mining going in the state with a broad marketing campaign that was outlined by Sanderson.

Aug 1, 2013

By H. M. Stewart, N. F. Dawson, J. P. Beukes, P. G. van Zyl, Q. P. Campbell, A. Jordaan, R. I. Glastonbury, L. N. Sadiki

"SynopsisThe physical properties of oxidative sintered pellets produced from typical South African UG2 ore are compared with the physical properties of pellets produced with conventional South African metallurgical-grade chromite ore (from the Lower Group 6 or the Middle Group 1 and 2 seams). A statistical evaluation of the cured (sintered) compressive strengths proved that pellets prepared from UG2 ore are likely to have the same, or better, compressive strength than pellets prepared from metallurgical-grade chromite ore. The cured abrasion strength of the UG2 pellets was also superior to that of the metallurgical-grade pellets. Scanning electron microscopy (SEM) backscatter, secondary electron, and elemental X-ray mapping were used to determine the reasons for the general superior strength of the UG2 pellets. The case study UG2 ore also required 13 kWh/t less energy for milling to attain the required particle size distribution prior to pelletization, which can lead to substantial cost savings. Results presented in this paper can be utilized by ferrochromium (FeCr) producers to better quantify the advantages and disadvantages associated with the use of UG2 ore for FeCr production.IntroductionChromite, a mineral of the spinel group, is the only commercially viable source of virgin chromium units. Geologically, commercial chromite deposits in the world are found in three forms, i.e. alluvial-, podiform-, and stratiform-type deposits (Murthy et al., 2011; Cramer et al., 2004). Alluvial deposits were formed by weathering of chromite-bearing rock with the subsequent release of chromite and gravity concentration by flowing water. However, these deposits are relatively small and of comparatively minor commercial interest. Podiform-type chromite deposits usually occur as irregularly shaped pods or lenses, and their distribution within a mineralized zone is usually relatively erratic and unpredictable, making the exploration of these deposits difficult and costly (Cramer et al., 2004). Stratiform-type chromite deposits occur as parallel seams in large, layered igneous rock complexes with more regular layering and lateral continuity (Cramer et al., 2004). The largest example of a stratiformtype chromite deposit is the Bushveld Complex (BC) in South Africa, which holds an estimated three-quarters of the world’s viable chromite ore resources (Cramer et al., 2004).Several chromite seams exist in the BC. The seams of economic interest are the Lower Group 6 (LG6), the Middle Group 1 and 2 (MG1 and 2), and the Upper Group 2 (UG2) seams (Cramer et al., 2004). The LG and MG seams are specifically exploited for their chromium content, while the UG2 seam is mined primarily as a source of platinum group minerals (PGMs) (Xiao and Laplante 2004). Extraction of the PGMs from the UG2 ore usually involves the liberation of the sulphide by milling and subsequent recovery of the PGM concentrate through flotation (Xiao and Laplante, 2004). Chromite in the PGM concentrate is undesirable; therefore, PGM recovery circuits are specifically designed to ensure maximum rejection of the chromite to the tailings stream. However, the chromite in the PGM tailings can potentially serve as feedstock for ferrochrome (FeCr) production, after beneficiation to increase the chromium content."

Jan 1, 2015