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The Particulate Mineralogy Unit has been established at the College Park, Maryland, Metallurgy Research Center. The Particulate Mineralogy Unit will have the responsibility within the Bureau of Mines for the characterization of particulate minerals which have potential for adverse environmental effects. The Unit will provide a focal point for identifying particulates in connection with environmental problems related to the activities of agencies such as OSHA, HEW, EPA, and MESA. The Particulate Mineralogy Unit is seeking to clarify the ambiguities surrounding the mineralogy of and terminology used for asbestiform minerals and other mineral particles. The Unit?s investigations of the morphology, composition, and structure of asbestiform minerals and their nonasbestos analogs have made its members recognized experts in this field. The information which it develops on the characterization of asbestos and other particulate mineral forms such as silica should provide a technically rational basis for decisions by regulatory agencies. Those desiring further information, contact Dr. W. J. Campbell, Program Coordinator, College Park Metallurgy Research Center, College Park, MD 20740, telephone: 301-344-4014. ALUMINUM: For over a month, domestic producers have priced 99.5 percent grade primary aluminum ingot at 48¢ per pound. In the same period, merchants raised ingot quotes by 1.5¢-2.5¢ to a range approaching 44¢-47¢ per pound.

Jan 1, 1976

By S. k. Kim, H. B. Trinh, R. R. Srivastava

"Spent auto-catalyst is a promising secondary resource of platinum group metals (PGMs), which are being extensively used in automobiles catalytic converters to control the hazardous gaseous emissions (CO, NOx and hydrocarbons). Several pyro or hydrometallurgical routes has been employed to recover PGMs from such spent materials but there is no proper process for recovering the other constituents metals. Therefore, it causes the loss of other major constituents like, Al and Mg along with rare earth metal Ce. In the present study, we investigate the dissolution of Al and Mg using sodium hydroxide (NaOH) roasting followed by a sulfuric acid (H2SO4) leaching; thereby concentrating the PGMs and Ce in leached residues. The effect of roasting temperature, time and amount of NaOH were varied. Subsequently, the dissolution behavior of metals in H2SO4 as a function of acid concentration was investigated from the roasted samples. At an optimal condition for roasting at 600°C with 1:1 NaOH-to-catalyst ratio and 60 min duration, the maximum of Al and Mg were dissolved in 1 M H2SO4 solution at ambient temperature (~25°C). Thus obtained leached residues containing enriched PGMs and Ce content can be treated separately for the recovery of these high-value metals.INTRODUCTION Spent auto-catalyst has been considered as a potential resource for recovering the platinum group metals (PGMs) (Jha et al., 2013). The commonly used auto-catalyst is made of cordierite (2MgO.2Al2O3.5SiO2) in which the chloro complexes of PGMs are impregnated onto the surfaces of porous washcoat of alumina substrate (Aberasturi et al., 2011). The average concentration of PGMs in ore are 2-4 g/ton for Pt, 7-2 g/ton for Pd and 0.2-0.5 g/ton for Rh, whereas, an individual catalytic converter weighing about 1 - 2 kg contains on average 1.56 g Pt, 0.62 g Pd and 0.156 g Rh (Upadhyay et al., 2013). Moreover, recovery of PGMs from spent auto-catalyst offers other advantages like, simple process, low cost and less pollution, as compared to recovery from primary resources (Dong et al., 2015).Therefore, technologies to recover PGMs from spent auto-catalyst has become attractive in the recent past and their recycling contribution has been accounted for 35% Pt, 26% Pd and 36% Rh of the quantity consumed in the production of auto-catalysts (Johnson Matthey, 2016)."

Jan 1, 2017

By C. P. Broadbent

The process metallurgy of many nickel laterite smelting operations is controlled largely by the physical chemistry of the slag system. Consequently, accurate phase diagram information and physicochemical property data are essential to interpret and predict the behaviour and optimisation of the overall process. The system (SiO2 - MgO - FeO) first described by Bowen et al. between 1914 and 1935 and the system (SiO2 - MgO - FeO - Fe2O3) determined by Muan and Osborne in 1956 are of particular relevance to the study of nickel laterite smelting slags as these systems form a reasonable approximation of many industrial slags. This paper will review the literature for these (and other relevant) phase systems. In addition data available from the ternary and (quasi)ternary phase diagrams will be compared with data obtained from industrial slags. The physico-chemical properties under consideration will include; melting and crystallisation behaviour (solidus and liquidus temperatures), viscosity - temperature relationships, heat flux considerations, electrical conductivity, surface and interfacial tension.

Jan 1, 1993

By K. S. Gritton

The Bureau of Mines investigated the feasibility of numerlcally modeling the sorption of cobalt, a vulnerable strategic and critical metal, from spent copper leach solutions in a multiple-compartment ion-exchange (MCIX) column. Equilibrium resin loadings, cobalt-sorption kinetics, and resin-fluidization characteristics were determined in simple laboratory tests, and a numerical model was developed to predict cobalt extraction and the MCIX-column resin inventory based upon the test results. The model was implemented on a microcomputer to approximate the solution to the set of differential equations that govern model performance. Results compared very well with data from 12 pilot-scale MCIX-column experiments. The average difference between predicted and actual cobalt extractions was 3.2 pct; the maximum difference was 9.3 pet. The actual and predicted resin inventories differed by an average of 5.8 pet, and the maximum difference was 12.0 pct.

Jan 1, 1987

By J. A. S. Tenorio, K. S. Barros, D. C. R. Espinosa

In the last decades, authors have been focused in the development of a cyanide-free bath for the electroplating industry of brass due to the risks that involves the use of cyanide and they have been evaluated the electrodialysis as an alternativemethodforthetreatmentoftheeffluentgeneratedinthistypeofindustry because ofthe limitationscaused bythe chemical precipitation. Hence, thepresent paperaimedtodeterminethelimitingcurrentdensityoftheeffluentgeneratedinthe free-cyanide electrodeposition of copper and zinc using EDTA as chelating agent for the treatment of the effluent by electrodialysis. The synthesized solutions were preparedwith copper sulfate andzinc sulfate indifferent conditionsofpH (10–12) and proportion of cupric ions (30%, 50%, 70%). According to the results, the increase of pH and the cupric ions proportion caused an increase in the limiting current density because of the larger amount of anionic species in solution and the consequent difficult to achieve the concentration polarization phenomenon. (cid:1) (cid:1) (cid:1)

Mar 1, 2018

By Nikhil Dhawan, SHAILA MIR

The emerging problem of electronic waste has promoted the interest in exploring metal recovery from secondary sources under the umbrella of urban mining. This study presents the physical and chemical characterization of various components present in end-of-life laptops to help ascertain the sites of metallic values and develop sustainable and environment-friendly recycling. The recycling potential of a laptop is evaluated by sequential disassembly, separation, and characterization of components such as body (49.8 wt.%), printed circuit board (9.7 wt.%), hard disk drive (4.9 wt.%), and battery (12.4 wt.%). The printed circuit boards comprise metallic values, majorly copper (25 wt.%), tin (5.8 wt.%), and lead (3.1 wt.%). The precious metals (Au, Ag) with an economic advantage are abundantly present in electronic components such as integrated circuits, capacitors, resistors, and processors. Critical elements such as lithium, cobalt, and rare earth elements are detected in the discarded laptops' batteries and hard disk drives. The recycling potential representing the amount of material that can be recycled in various components, depending on the type, concentration, and purity, is determined in the range of 36–100%. On average, a unit laptop contains~ 386 g of Cu (14.45 wt. %), 49.73 g Co (1.86 wt. %), ~346 mg Ag, ~141.2 mg Au, ~650 mg of rare earth elements (Nd, Dy). This study presents a database for investigating integrated and economical recycling techniques from different components of a laptop, and an overall process flow is also proposed.

Jul 24, 2021

By Warren B. Davis

Introduction If a subject this broad were to be covered in even moderate detail, it would require a set of books about the size of an encyclopedia. Since an acceptable length for this paper is a small fraction of one book, it will have to consist of a few samples of the subjects that I think are the most pertinent to World Fossil Fuel Economics. I plan to discuss the trends in world energy demand, particularly in the U. S. and Europe; the consumption patterns and cost patterns of oil, gas and coal; the prospects of synthetics; and some of the effects of government regulation of fuel economics. World Energy Demands Fig. 1 shows Free World energy consumption by principal areas for the period from 1950 to 1970 and a forecast for the period from 1970 to 1985. These figures include only the measurable forms of energy. An example of energy consumption that is not measured is the wood a peasant might cut in the forest and bum in a fireplace to heat his home. This omission probably is a very small part of the total. This forecast is not identical with that of Wayne E. Glenn (see Page 22), but the differences in total energy consumption are not significant. The U. S. consumption, which was 55 percent of the world total in 1950, had declined to 45 percent by 1970, and is expected to decline further to 38 percent by 1985. Western Europe has consumed 28 percent of the total from 1950 to 1970 and is expected to lose share slightly between 1970 and 1985. The most spectacular gainer is Japan, which increased consumption from 2.5 percent in 1950 to 7.5 percent in 1970, and is expected to reach nearly 17 percent by 1985. The over-all Free World total has grown from 62 quadrillion Btu (equivalent to 29 million B/D of crude oil) in 1950 to 151 quadrillion by 1970, an average growth rate of 4.5 percent/year. This total is expected to grow at a rate of 5 percent/year between now and 1985, reaching 315 quadrillion Btu (equivalent to nearly 150 million B/D). Fig. 2 shows which fuels supplied this energy between 1950 and 1970, and gives an estimate of how it will be supplied between 1970 and 1985.

Jan 1, 1971

By Baohua Guo, Xuelin Yang, Tingkan Lu, Hailin Sun

The work presented in this paper mainly involves two parts. Firstly, the fundamental characteristics of the high pressure carbon dioxide gas fracturing technique (CO2 technique), including, a proposed method of TNT equivalence calculation, which is used to calculate the TNT equivalence of discharge of CO2 technique, and the comparison of the explosion volume generated by dynamite and expansion volume of liquid carbon dioxide is conducted to show the differences of fragmentation capacity between the two of them. Secondly, the coal seam fragmentation mechanisms of CO2 technique are proposed, including, 1) Gas jet cutting and penetration by shaped charge, 2) Gas volume expansion by changing phases of carbon dioxide, 3) Coal seam softening by destress blasting and 4) Coal seam fragmentation by discharge vibration, associating with the mechanisms, the equations for calculating fragmentation radius are developed and verified.

Jan 1, 2017

By N. Schmalbein, L. von Ketelhodt, L. Kotelo

"The mining industry continues to remain challenged. Lower commodity prices, increasing labor costs and more importantly diminishing reserves are amongst some of the primary factors contributing to the difficulties faced. Ore sorting technologies have demonstrated their potential to improve the downstream beneficiation performance. The general processing route sees all primary crushed material milled for liberation and then processed in accordance with characteristics of the gold therein, i.e.: refractory golds would require direct leaching or oxidation whilst free gold would follow the conventional cyanidation process, after gravity concentration. Ore dilution increases the associated operating costs within each stage of this process. The opportunity to process the same throughput at a higher grade can only be achieved through pre-concentration. Sensor based sorting has been examined on numerous occasions by various gold producers. Test work carried out on different bulk low grade gold ores has shown the successful applicability of ore sorting to remove waste, whilst maintaining high recovery rates of gold. The results of a combined XRT/Laser sensor sorter have shown grade improvements of over 300% from feed grades of 0,25g/t to 1,15g/t at gold recoveries of 66% and waste ejection rates of 85%. This paper presents some of the results from the work undertaken by STEINERT with respect to gold sulphide ore sorting and presents a modelled financial scenario, which can enable a company to target and reclaim low grade ores.INTRODUCTION The mining and minerals processing industry presents with many different challenges including, volatile commodity prices, increasing labor costs and more importantly diminishing reserves. Conventional processing routes will continue to play a crucial role in the beneficiation process, however innovative methods of reducing operating costs and optimizing on the overall circuit performance is where technologies such as sensor based sorting come into the fore. Sensor based sorting as a dry mechanical process not only reduces water consumption by eliminating unnecessary waste but also reduces the requirements for reagents in the downstream processes. Sensor based sorting under dry conditions presents a highly efficient alternative to wet pre-concentration methods such as dense medium separation (DMS)."

Jan 1, 2017

By P. Archer

The Blondeau Formation has been examined in a stratigraphic drill section at Barlow Lake. The formation contains pyroclastic flows and volcanogenic sediments throughout, but epiclastic sedimentary rocks dominate the upper parts of the section. Five distinct types of pyroclas tic flows are known in the section, as well as minor mafic lava flows. Volcanogenic sediments are commonly intercalated with the true volcanic rocks. Sedimentary rocks include fine-grained intraclastic sandstones, heterolithic sandstones and green and black shales. Interpretation of the origin and relative disposition of the volcanic and sedimentary rocks favours a model of near-emergent vulcanism in an upward shoaling environment.

Jan 1, 1984

By Irving Hartmann

1. Under the conditions of the tests described herein, the proper use of an incombustible stemming plug of the type discussed prevented ignitions of gas in all tests during the firing of 21 single shots of permissible explosive in cool. In two tests with multiple blasting (four and five shots each) no ignitions resulted. 2. The results of a few tests in this investigation and of numerous tests made previously indicate that fire-clay stemming of the same weight as an incombustible plug provides about the same degree of protection as the plug against gas ignitions during blasting of coal by permissible explosives. 3. The hazard of gas ignition on firing charges of non-permissible 40-percent gelatin dynamite in coal was reduced but not eliminated when the shot holes were stemmed with one or two incombustible plugs or with an equivalent weight of fire clay. 4. On the basis of this investigation, the Bureau of Mines considers the proper use of incombustible stemming plugs of the design tested, under the conditions of the tests described in this paper, to be of equivalent safety as the same weight of fire-clay stemming. This report does not constitute approval or disapproval of the incombustible stemming plugs by the Bureau of Mines. 5. The test data indicate that misfired charges in shot holes stemmed with the incombustible stemming plug cannot be disposed of with certainty by the procedure recommended by the manufacturer. In this investigation the misfired charges failed to detonate in 30 percent of the trials.

Jan 1, 1950

By C. R. Nisewanger, F. W. Brown

"The velocity of detonation of an explosive is one of its most important properties, because its performance depends markedly on the rate at which it releases its energy. Fortunately, the velocity of detonation is one of the few properties of an explosive that can be measured precisely. However, the velocity of detonation of an explosive may depend on several factors other than its chemical composition, such as density, physical state, degree of confinement, nature of confinement, and magnitude of initiating impulse. Presumably for an explosive of fixed chemical and physical properties there are certain limiting conditions of confinement and initiation under which the explosive will detonate at a maximum constant and uniform velocity. This velocity is its ""ideal"" velocity of detonation. It is obvious, however, that in order to evaluate performance properties of an explosive in all of its applications it may be necessary to measure its velocity of detonation under a number of conditions in which the velocity of detonation is far from the maximum ""ideal"" velocity.. Under certain-conditions the velocity of detonation may even,be,different at different points in the explosive.It is .relatively simple to determine the velocity of detonation of an explosive under a. standard set of conditions if one is free to use large quantities of the explosive and to form it into a convenient shape. Under these circumstances; one can use a thin column of explosive a meter or more in length. The time required for an explosion to travel the length of the column will not be less,of the order a few ten-thousandths of a second and can be readily and accurately measured .by means of the standard spark chronograph or by photographing the explosion with a rotating-drum camera. However in many applications the explosive charge may be of relatively small dimensions arid may not be in a form convenient for making velocity measurements and often may be enclosed in a case or other confining medium. It may be necessary to determine the velocity of detonation over distances of the order of a few centimeters, in which case the time intervals to be measured will be extremely small. For example, the time required for an explosion to traverse 1 centimeter of tetryl is of the order of 1.5 microseconds.Since no satisfactory method of determining time intervals of the order of magnitude of a few microseconds within an explosive charge was available,, at least not for all conditions that might be encountered in practice, it was necessary to develop a special electronic chronoscope which is capable of measuring time intervals as small as a microsecond with a fair degree of accuracy. This report describes the chronoscope and its application to measurements of velocities of detonation in explosives."

Mar 1, 1946

By A. A. EI-Geassy

High-grade iron ore fines rejected from the DRI plants (>96%Fe2O3) were isothermally reduced in 30-60%CO/H2 gas mixtures at 973-1273K. The freshly reduced reaction products were then subsequently carburised in either Hz/CO or H2/CO/S mixtures at 823-1 073K for 30-120 min. The thermogarvimetric technique was used to follow up both of reduction and carburisation reactions as a function of time. The carburised samples were characterized by X-ray and Mossbauer techniques. Chemical and carbon analyses were also applied. The influence of temperature and gas composition on the reduction behavior was investigated. The calculated values of apparent activation energy, application of gas-solid mathematical formulations were correlated with the microstructures to predict the reduetion mechanism. The influenee of carburization time, temperature, CO contents in H2/CO or H2/CO/S were investigated. A conversion extent of Fe to Fe3C was taken as a measurable index for the efficiency of carburization rcaction under the different experimental conditions.

Jan 1, 2003

By C. M. Bartley

Canada has been a producer of sulphur in various forms for about 100 years, Pyrites, as a source of sulphur dioxide for the manufacture of sulphuric acid, were being mined in the 1860's. Smelter gas, for the same purpose, has been recovered since 1928. Between 1935 and 1943, and from 1952 to the present, elemental sulphur has been produced in Canada from two raw material sources and by several methods. This paper attempts to present a view of the current status of the elemental sulphur industry in Canada based on the sour gas fields of Alberta and British Columbia. Production from this source has increased rapidly in the past 12 years to make Canada one of the major sulphur producers of the world. The present industry in Canada relies mainly on sour gas sulphur and it is expected that it will continue to grow in the future. However, before describing current activity relating to sour gas it may be of interest to outline briefly the early pyrite activities, the roots of the sulphur industry in Canada.

Jan 1, 1964

By M. B. Bransford

A calculation procedure was evolved by the Bureau of Mines for determining the heat-transfer characteristics of dilute gas-solid mixtures in an externally heated tube. The procedure accounts for differences in gas and particle velocities and covers a range of particle sizes. Heat transfer coefficients obtained by the calculation procedure are compared with values reported in the literature.

Jan 1, 1970

By S. S. Wang

Dialkyldithiophosphinates are a new class of flotation collectors for base metal sulfide ores. Structurally, they are quite different from the conventional collectors such as mercaptans, xanthates, thionocarbamates and dithiophosphates. Collectors Structures [Mercaptans R-SHS Xanthates R-OCS-M+ Thionocarbamates R-OCNH-R Dithiophosphates 2 R-CCNH-R' Dithiophosphinates (R) 2-PS-M+ ] In the above structural formula, R and R' stand for a hydrocarbon radical, and M+ is an alkali metal or ammonium cation.

Jan 1, 1982

By Glaydson Simões dos Reisr

Micropore organosilicas (MOs) were synthesized using methyl-phenyl-polysiloxane as precursor. The MOs were characterized using several analytical and functional techniques. The materials were assigned as micropores materials, with specific surface area up to 642 m2 g-1 and yield up to 72.55%. The adsorbents have hydrophobic surfaces and were used for removal of diclofenac from aqueous solutions. The adsorption kinetic and isothermal data were well described by the general order and Sips models, respectively. Diclofenac exhibited a better affinity than NM and the mechanism of adsorption suggested that hydrophobic groups play a key role in the adsorption process.

Aug 17, 2017

By I. C. Christopher

Introduction The geology of the Cochen-our Willans gold mine has been described in reports by the late Dr. H. C. Horwood (1) in 1940 and by Dr. J. P. Nowlan (2) in 1947. Information from these and other (unpublished) reports has been incorporated in the present paper, together with some recent ideas regarding structural features which are at present being used to locate ore shoots. Location and History The mining claims of Cochenour Willans Gold Mines, Limited, occupy 705 acres in Dome township, on the east shore of Red lake opposite McKenzie island. Adjoining properties are those of McKenzie Red Lake Gold Mines on the west, Boymar Gold Mines on the north, Marcus Gold Mines on the east, and Martin-McNeely Gold Mines on the south. The claims of the original group were staked by W. M. Cochenour, Dan Willans, and H. G. Young, and the Cochenour Willans Syndicate was formed in 1928. Work was carried out by the Syndicate and several other companies during the next eight years with inconclusive results, due to the irregular occurrence of the ore. In 1936, Cochenour Willans Gold Mines, Limited, was incorporated and production was finally started late in 1939.

Jan 1, 1951

In recent years, coal beneficiation has gotten considerable attention. Selective oil agglomeration has been accepted as the best method to produce clean coal with a high removal of pyrite sulphur. In this study, spherical oil agglomeration of Datong coal fines was carried out using diesel oil as a bridging liquid. The oil agglomeration has a surface properties based on coal cleaning technique. The effects of fundamental parameters have been investigated including the concentration of bridging liquid, the size of coal particle, the solid content of slurry, the agitation time and rate, pH, surfactants on the agglomeration performance and various salts on the ash rejection and removal of pyrite of the agglomerated products. The optimum conditions of particle size, diesel concentration, solid content, agitation speed and time, pH and the dosage of active agent have been determined as less than 8µm, 20wt%, 1200r/min and 10 minutes, 7.5g/t and 100g/t, respectively. Under these conditions the ash content in the products can be achieved 1.5% below, the ash rejection was up to 92%. It has been observed that ionic strength of the aqueous medium affects the agglomeration performance. The precombustion coal cleaning process based on improved selective agglomeration results in high ash and pyrite sulphur removals. Over 80% removal of pyrite sulphur can be achieved from run-of-mine coals by offering a more cost-effective sulphur reduction solution rather than any other SO2 removal technology. In addition, the removal of pyrite sulphur is very necessary for not only the prevention of environmental pollution but also economical reasons.

Jan 1, 2014

By M. A. Halim, V. I. Lakshmanan

Recycling is one of the key elements for sustainable process development for the recovery of value-added products and reducing environmental impact. Process Research ORTECH Inc. has developed several innovative and sustainable technologies, which minimizes the use of water, and chemicals for the recovery of gold, vanadium and gallium from secondary sources by maximizing the recycling of reagents, and reuse of water from process effluents.

Jan 1, 2015