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By C. G. Anderson, L. G. Twidwell

"Throughout the world, there are many orebodies or materials which have significant value but also contain arsenic, antimony, and mercury. As regulations on the transport, exposure, disposition and emission of these elements have become more stringent; it has become increasingly more difficult to derive the values from the resources. This paper outlines the fundamentals of alkaline sulfide hydrometallurgy and its successful application to arsenic, antimony and mercury bearing ores, concentrates, by-products, and other materials.Fundamental Alkaline Sulfide HydrometallurgyHydrometallurgical methods can be employed for treatment of gold, arsenic, antimony, tin and mercury containing materials, concentrates and ores as well as complex ones containing any number of metals. The alkaline sulfide system is one of these and is essentially a mixture of sodium sulfide and sodium hydroxide. This is a unique hydrometallurgical system as it is a very selective lixiviant for the distinct leaching of tin, gold, antimony, arsenic and mercury [1-7]. Worldwide, it is employed industrially in the CIS, China and the United States for the production of antimony [8-15].As an example, when the system is applied to an arsenic containing material like orpiment, As2S3, a solution of sodium thioarsenite is formed. This is illustrated as:"

Jan 1, 2008

By John H. Hollomon

In a recent paper,' a very early suggestion by Ludwik2 concerning the nature of the mechanical behavior of metals has becn reexamined and extended. In essence it was suggested that there exists, at least under certain conditions, a mechanical equation of state; that the stress required for flow depends upon the instantaneous values of the strain, strain rate, and temperature, and not upon their past values. It is proposed that under these circumstances thc stress does not depend upon past history of these variables, but is like the temperature of a gas that depends only upon the instantaneous values of the pressure and volume. This notion has not been applied to present-day studies of metals, though it is especially applicable to the study of creep. It is the purpose of this paper to analyze the significance and possible range of applicability of this idea and to determine how it influences the accepted ideas concerning creep. Stress-strain Relations It is wcll known that the stress-strain curves of metals are influenced by both train rate and temperature. For a fixed strain rate and temperature there is associated with each metal a stress-strain curve. If either the strain rate or temperature is changed a new stress-strain curve will be characteristic (Fig. I). A much more genera1 relation between the effects of these variables is possible, however. Consider the stress-strain curves of Fig. I determined at

Jan 1, 1947

By John H. Hollomon

In a recent paper,' a very early suggestion by Ludwik2 concerning the nature of the mechanical behavior of metals has becn reexamined and extended. In essence it was suggested that there exists, at least under certain conditions, a mechanical equation of state; that the stress required for flow depends upon the instantaneous values of the strain, strain rate, and temperature, and not upon their past values. It is proposed that under these circumstances thc stress does not depend upon past history of these variables, but is like the temperature of a gas that depends only upon the instantaneous values of the pressure and volume. This notion has not been applied to present-day studies of metals, though it is especially applicable to the study of creep. It is the purpose of this paper to analyze the significance and possible range of applicability of this idea and to determine how it influences the accepted ideas concerning creep. Stress-strain Relations It is wcll known that the stress-strain curves of metals are influenced by both train rate and temperature. For a fixed strain rate and temperature there is associated with each metal a stress-strain curve. If either the strain rate or temperature is changed a new stress-strain curve will be characteristic (Fig. I). A much more genera1 relation between the effects of these variables is possible, however. Consider the stress-strain curves of Fig. I determined at

Jan 1, 1947

By L. Xu, N. I. Jayaraman, R. Bhaskar

The objective of this study is to develop a better understanding of the collection characteristics of dust measurement instruments used in mine dust control research with respect to properties of quartz and coal dust. Coal and quartz dust of narrow sues, with aerodynamic median diameters being approximately 2 µm, 4 µm and 10 µm, with quartz contents of l0%, 20%, 30%, 40% and 50%, were released in an aerosol characterization chamber using a fluidized bed aerosol generator. Dust was collected in MSA personal gravimetric samplers with l0-mm nylon cyclones, total dust samplers and Sierra 298 inertial cascade impactors. The samples were analyzed for mass and quartz content. A total of 21 experiments were performed for this study. The mass and quartz collection efficiencies of the total and respirable dust samplers and the impactor were determined. The data show that the amount of dust collected by the respirable dust sampler (respirable + oversize dust trapped in the cyclone pre-classifier) was, in general, less than the amount collected by the total dust sampler. The amount of dust collected by the impactor was higher than that collected by the total dust sampler. Quartz analyses of the airborne dust samples showed that the total dust and respirable dust samplers (including oversize dust) collect less quartz dust than at inertial impactor. The larger the median particle sire of the quartz and coal mixture, the lower the quart content of the dust collected in the samplers. For all three sires, the impactor was a better collector of quartz than the other instruments.

Jan 1, 1994

By W. F. Carew, H. D. Kessler, F. A. Crossley

AS part of a program on phase relationships and transformation processes of titanium alloy systems, the titanium-rich corner of the Ti-Mo-V system has been investigated. This region was surveyed primarily to supply information toward the development of a creep resistant, weldable alloy, with a minimum alloy content, for use in the 425° to 550 °C range. Specifically, the investigation was directed toward the development of a stable ß alloy with less total alloying additions than is found in the Ti-30 pet Mo alloy. A secondary objective was the development of a creep resistant, weldable a-ß alloy for application around 300°C. Molybdenum was selected as primary additive to titanium on the basis of an investigation1 which showed that the Ti-30 pet Mo alloy had promising elevated temperature tensile properties. Furthermore, aging studies1 showed no tendency for this

Jan 1, 1957

By D Macfarlane, T McMorran

  This paper describes the design and construction of the upper section of the Pike River Mine Access Road. The road extends 11 km from Logburn Road alongside Big River on the West Coast of the South Island of New Zealand up Pike Stream to the new mine portal on White Knight Stream (Figure 1). This new road starts on alluvial terraces, then partially follows an old logging road before entering virgin bush and traversing the true left bank of a steep sided gorge on Pike Stream some 50 - 100 m above the stream before dropping down to the mine entrance. Its development has been an extended process from route selection, consenting through to design and construction.   The paper focuses on the 1 km section of road between the Amenities Area (Figure 1) and the portal. This section of road is a steep section through the gorge, principally on Conservation estate, and has presented the most challenges and required the greatest effort to obtain the regulatory approvals, prepare the design and to construct. This paper outlines the history of the challenges faced and how the road was successfully developed.

Jan 1, 2007

By N. Patel

Many factors, from engineering and design to supply, installation, and operation affect the service lifespan of cast refractory linings. If a shortcoming occurs at any of these stages, the lining lifespan can be drastically reduced. Although not every aspect that can affect a cast refractory lining?s lifespan is outlined here, a few key points are highlighted, with an emphasis on the various installation parameters. Keywords cast linings, refractory lifespan, lining engineering and design, lining supply, lining installation, curing, dry-out.

Aug 1, 2013

By M. Remillard, M. Garon, D. Hodouin, M. Therien

"Nineteen streams in the copper and zinc flotation units of the concentrator of the Matagami Division of Noranda Inc. have been sampled f or particle size distributions, chemical assays, and gold and silver contents in each particle size interval. The data are upgraded by the mass balance package BILMA T. These results, in conjunction with microprobe analyses, are used to quantify the silver losses in the copper cleaning flotation stages and to determine how over-all silver and three silver-bearing minerals are recovered in the plant final products. RESUMEDix-neuf produits des circuits de flottation du cuivre et du zinc de la division Matagami de Noranda Inc. ont été échantillonnés pour leur distribution granulométrique, leurs analyses chimiques et Ie contenu d'argent et d'or des fractions granulométriques. Le bilan métallurgique a été obtenu à l'aide du programme BILMA T. Ces résultats, couples avec une étude minéralogique a fa microsonde, sont utilisés pour quantifier les pertes argentières aux diverses étapes de nettoyage du circuit de cuivre et pour déterminer la répartition de l'argent et des trois minéraux argentifères dans les produits finals de l'usine."

Jan 1, 1988

By Reinhold A. Errath

"The paper describes the problem related with contradiction to the development of sag mills, which one are becoming bigger in size almost every year. In this sense, the concentrator plants are being built more and more in remote areas where the power supply and network conditions are not necessarily covering the needs for the operation of such plants. It also illustrates the permissible tolerances in terms of commutation of the powerelectronics, based on already realized installations. Finally the paper gave an overview about the technical impact of a strong versus weak networks."

Jul 31, 2003

Electrocrystallization studies were conducted in a concentrated acid-copper electrolyte to determine the influence of chloride ions and glue on copper nucleation and on the structure of thin copper layers. Electrochemical experiments allied to SEM and XRD examination were performed to characterize the mechanism of nucleation in the presence of additives at 65°C. Results indicated that most of the copper nucleation from a 83 g dm-3 Cu2+ solution, with 140 g dm-3 of H2SO4 is achieved in a matter of milliseconds, Although the presence of chloride and glue, at the concentration levels tested, does not seem to substantially modify the nucleation mechanism, the morphology, nuclei density and the copper film structure and orientation are changed by the presence of additives and by electrolyte stirring.

Jan 1, 1999

By Bedford D. J

The post pillar cut and fill stoping method has been adopted by King Island Scheelite for the extraction of the main Dolphin orebody. The orebody is a massive, tabular deposit varying from 10 to 50 metres in thickness, and dipping at approximately 30¦ towards and under the sea bed. The mining method was selected for 1. maintenance of hangingwall support under the sea bed; 2. maximisation of first stage ore extraction; 3. flexibility of mining, allowing maintenance of grade and selective mining around waste bands within the orebody, and 4. compatibility of existing equipment both with stoping and the on-going underground mine development programme. Stope parameters were established on the basis of initial rock stress analyses, and since the undercut phase of mining the stoping programme has been monitored with various types of deformation measuring devices installed in a series of large diameter boreholes.

Jan 1, 1977

By Hocking G

For some underground structures, the use of the plane strain assumption in stress analyses may not be justified. The finite element method and photoelasticity have been used to obtain complete 3-D solutions, but, for various reasons, neither method has found universal use. The boundary integral equation method (B.I.E.M.) can be more efficient and economical than the finite element method for 3-D problems involving large volume to surface area ratios. A B.I.E.M. program developed for calculating stresses and deformations in infinite elastic media has been used to determine the 3-D distributions of stress around T- and Y- junctions of circular tunnels in stress fields in which the ratios of horizontal to vertical stress are 0, 0.33, 1.0 and 2.0. For the T- junction considered,stress concentrations at the intersection are approximately twice the plane strain values. Except where horizontal field stresses are high, the stresses in both tunnels approximate the plane strain values at about two tunnel diameters from the point of intersection of the tunnel centre lines. The stresses in the two branches reach those for the corresponding plane strain, two parallel tunnel case two diameters from the point of intersection of thq inner tunnel walls. Very high stress concentra- tions occur in the pillar of rock between the inner tunnel walls near the point of intersection.

Jan 1, 1976

Adsorption Effect on Multi-Heavy Metal Ions in Wastewater by Water-Washing Waste Saccharomyces cerevisiae

Sep 13, 2010

By L. P. Teas

In spite of the influx of operators into the Gulf Coast anxious to retrieve their depleted production in other fields, and in spite of very active application of the most scientific geophysical methods to locate new producing areas, the results have been very discouraging and the year has failed to produce more than the average results for a Gulf Coast year. During the year seven new oil fields, some of which are still of very little importance, and one new gas area have been discovered. These fields are Tom Ball, Greta, Cleveland, Raisin and Garwood in Colorado County; Louise and Premont in Jim Wells County, and the new producing gas area near Ace in southern Polk County. During the year salt has been found for the first time at Carlos and Esperson. New producing areas have been developed on East Stratton Ridge, Hockley, Hull, Port Neches, near Pettus in Bee County, and on the O'Connor Ranch in Victoria County. The total production for the Gulf Coast for the year was 62,837,435 bbl., an increase of 18,589,000 bbl. over 1932. During the year, 1307 wells have been drilled of which 207 were wildcats, compared with 653 wells and 141 wildcats the previous year. The total daily production at the end of the year was 165,201 bbl. At present there are 3100 oil wells producing. The average production per well is 55.5 bbl. per day. The price of crude fluctuated considerably during the year, beginning at 80c per barrel and closing the year at $1.04 per barrel. Completion data for 1933 are as follows:

Jan 1, 1934

By K Inoue

The pressure oxidation of molybdenite concentrates in acidic and alkaline media has been studied. The conditions of the selective oxidation of copper and iron sulphide minerals with a quantitative copper leaching by ferrous-ferric-sulphate solution have been found and explained from the point of view of electrochemical kinetics. The partly oxidised residue consisting of molybdenite and (hydro-) oxide of iron (III) was then decomposed by oxygen in alkaline media. Effects of the main parameters, such us oxygen pressure, leaching temperature, solid-liquid phase ratio, autoclave stirring speed as well as lixiviants nature on the molybdenite oxidation rate have been established.

Jan 1, 2000

By Roger Keller, Jason Ryan

A number of studies have evaluated excavation methods for the construction of subsurface facilities for a potential deep geologic repository for the disposal of nuclear waste at Yucca Mountain, NV. Many of these studies suggest that where TBM (tunnel boring machine) methods are not applicable and alternative mechanical excavation methods can not efficiently excavate harder rock drill and blast methods may be the most efficient means of excavation. However, a number of concerns regarding drill and blast applications have been raised in these evaluations, most notably the affects of blasting on the surrounding perimeter, as isolation of the waste by the natural barrier of the surrounding rock is a key element in the concept of a deep geologic repository.

Jan 1, 2001

By Middlebrook PD

The problems of education and research in the extractive metallurgy area are being tackled by the University of Melbourne through activities centring on the Department of Chemical Engineering. The establishment of the G.K. Williams Laboratory and the enhance- ment of the teaching of material relevant to extractive metallurgy in the Chemical Engineering course aim-at providing graduates and experienced researchers for the industry and at providing a strong research group carrying out industrially significant research in the area of pyrometallurgy.

Jan 1, 1986

By Maria Baker, Kristina Gjerde, Lisa Levin, Verena Tunnicliffe, Lenaick Menot, Rachel Boschen

Deep-sea mining is rapidly approaching the test-mining phase to prepare for commercial mining in multiple oceans, both in areas within and beyond national jurisdiction. The first test-mining operations are likely to focus on seafloor massive sulfides found at active and inactive hydrothermal vents within national jurisdictions – possibly in the coming months. Beyond national jurisdictions, the International Seabed Authority (ISA) is developing the regulations to oversee exploitation of polymetallic nodules, massive sulfides and cobalt crusts. The Deep Ocean Stewardship Initiative (DOSI) minerals working group has, over the last 3 years, made formal submissions on the regulatory framework, on the draft exploitation regulations, on the article 154 review of ISA and on the initial environmental regulations. In advance of both test and commercial mining, we urgently need to identify and develop comprehensive, ecosystem-based management practices for deep-ocean environments subject to mineral extraction. Transparent criteria for deep-sea institutional and corporate social responsibility also need to be established. Proactive development of management practices, frameworks and policy prior to the onset of mining will facilitate some degree of protection and preservation of the marine environment, whilst enabling the use of seabed mineral resources. The DOSI minerals working group constitutes a broad spectrum of scientific, industry, legal and policy expertise. We provide expert opinion, both in collated and individual response forms, on deep-sea mining related concerns to ISA and national bodies. Our publications and workshops on key concepts raise awareness and provide scientific updates on ecosystems targeted for mining. See http://www.dosiproject. org minerals working group and join us to further this work.

Jan 1, 2017

By S. J. Page, W. R. Reed, J. A. Organiscak

NIOSH continues to conduct respirable dust control research for surface mine blasthole drilling operations. Research areas have included testing variables (shroud leakage area, drill deck cross-sectional area, shroud height, collector-to-bailing airflow ratio, etc.) that have the most impact on respirable dust control, development of a dust collector inlet hood, development of a dust collector dump point shroud, and testing of a small diameter water separating sub. This paper summarizes the results of the aforementioned research that has been completed. Additionally, past dust control research for drilling operations of both underground and surface mines completed by the U.S. Bureau of Mines, created in 1910 and incorporated into NIOSH in 1997, is reviewed.

By W. A. Hustrulid, N. A. Ross

An analysis of the design of medium to hard rock tunneling machines is presented. The developed equations are used to compare performances and machine requirements using kerf and fixed pick cutters to bore a given rock. With the use of pick cutters, required thrusts can be greatly reduced and still achieve the same boring rate as with present day tooth or kerf cutters. It appears that the cutting coefficient, which for most boring machines is of the order of 0.1, should be increased to one or larger to facilitate rock removal by cutting rather than grinding. The depth of cut and the indexing distance should be greatly increased to make use of inherent rock weakness.

Jan 1, 1971