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By Eggleton R. A

X-ray diffraction techniques are commonly used in the identification and quantification of fine-grained materials. A relationship exists between the size of crystals in a sample and the degree to which they diffract X-rays. The Scherrer equation relates the broadness of diffraction peaks to the size of crystals responsible for diffraction (Klug and Alexander, 1974). Relatively large crystals of the order of I - 10 ¦m strongly diffract X-rays; the diffractogram of such crystals exhibit narrow intense peaks. As the size of the crystals in a sample is reduced, diffraction peaks become broader and less intense. Crystals less than 10 nm generally exhibit broad, diffuse and low intensity peaks. Some material is so fine-grained and poorly-diffracting that X-ray patterns show very little information in a normal one-hour scan thereby necessitating very long acquisition times of up to 12 hours. The term poorly-diffracting material (PDM) was coined for such material found within the bauxite deposit of Weipa, northern Queensland (Tilley and Eggleton, 1994; 1996). Common regolith minerals such as hematite, goethite and layer silicate clays are quite commonly fine enough to possess a poorly-diffracting character. Noncrystalline and poorly crystalline Fe-Si-Al-oxyhydroxides such as allophane, opal, ferrihydrite and hisingerite, have either a nondiffracting (amorphous) or poorly-diffracting nature (Eggleton, 1987).

Jan 1, 1997

By W. P. Campbell

THE investigation herein described had its beginning in the chemical laboratory of the Department of the Interior, Calgary. After the transfer of the natural resources to the Province of Alberta in 1930, the laboratory was closed and the investigation discontinued, but in 1933, with the permission of the Director of the Mines Branch, the work was again taken up and brought to completion. OBJECT OF THE INVESTIGATION The object of the investigation as originally planned may be stated as follows : (1) To determine the chemical composition of the limestone formation underlying Turner Valley gas field. (2) To identify 'beds' in the limestone, if such existed, with definitecharacteristics which would mark them from immediately overlying and underlying measures. (3) To relate information acquired on the composition of the limestone to the occurrence of oil and gas in the particular section examined. Definite information was lacking as to the exact chemical composition of the limestone and of its variations in composition at various depths. The formation was generally referred to in the field as the 'dolomitic' limestone, but the depth to which the dolomitized zone extended and the degree to which the limestone generally had become dolomitized were not known. Jn the drilling and logging of wells, the recognition of suitable 'markers' in the various formations is a matter of some importance. Markers are generally relatively small but widespread members of a formation, which have some characteristic property, of colour, composition, or form, by which they may be identified, and with them, consequently, the formation of which they form a part. In the formations above the limestone in Turner Valley, a number of well defined and easily recognized markers are known to geologists, drillers, and others interested in the field. Many of these markers Hand out in sharp contrast to adjoining measures and are therefore easily recognized; in others, the contrast is less sharp, with consequent difficulty in identification.

Jan 1, 1937

By Jannie van Deventer

"Innovation in the minerals industry has been lagging behind comparable industries like oil and gas. An incremental innovation culture that tolerates long lead times between invention and adoption has been exacerbated by a research grant structure that inhibits radical idea generation. Entrepreneurs who can make the link between ore source, technology and finance will cause a shift in innovation culture and open up substantial opportunities in the minerals industry of the future. By extrapolating existing trends in technology within and outside mineral processing, a crystal ball vision of future innovation is shaped with the aim to lower energy and water demand, reduce CO2 emissions, decrease operating and capital costs, reduce environmental impact, and secure a social licence to operate. Advances in nanotechnology, advanced materials and biotechnology will impact mineral processing, but the initiative for technology transfer must come from mineral processors. Laminates of graphene oxide can offer efficient filtration and separation media, while microfluidic devices will be used for desalination, solvent extraction and analysis. Substantial progress is expected on benign lixiviants and separation agents, such as nanoscale supramolecular hosts that can serve as high-capacity, selective and recyclable ligands and sorbents, and solid aminobiphosphonate-based adsorbents. Radical ideas for the recovery of precious metals from non-assayable ores and the generation of energy above unity will be adopted in selected minerals projects. In-situ mining in which microbes generate lixiviants at mineral surfaces will simplify processing circuits. Specific ores will be subjected to microwave processing and electropulse liberation to enhance recovery. Ultrafine grinding using devices of low energy consumption will be done mainly dry, followed by dry separation. New flotation cells will remove efficiently either coarse particles or ultra-fine particles, with mineral surfaces being modified not just by new reagents but also by selective microbes. Innovation in mineral processing indeed has a bright future."

Jan 1, 2014

By Gene R. Reid

The contract objective is the development and in mine testing of an Automatic Fire Control System (AFCS) for mobile underground metal mining equipment. The effort described by this report covers the period from June 21,1975 through June 30,1976 and accomplished the following tasks: ? Preparation of Data Handling Plan and data acquisition which included visits to twenty mine sites in eleven states, visits to Bureau and MESA facilities, and a literature survey. ? Data analysis which determined the most hazardous type of vehicle for use in the demonstration, and design requirements for the AFCS, ? Development of recommended design concepts for the AFCS. ? Design and development of the AFCS including tests on a full-scale mock-up of a load-haul-dump (LHD) vehicle. ? Underground fire tests on an ST-2B-LHD vehicle at the Hecla Lakeshore mine Casa Grande, Arizona.

Jan 1, 1976

By Gaudin. A. M., S. C. Sun

THIS paper presents the results of a study of the relationship of the electrokinetic or zeta potential to flotation phenomena. The relationship is established on the experimental evidence that mineral behavior in flotation and in cataphoresis is generally governed by the chemical properties and amount of the reagents adsorbed at mineral surfaces. Cataphoresis1-5 or electrophoresis is the name given to the movement of a charged particle in a liquid medium under the influence of an applied electric field. Mineral behavior in cataphoresis, as indicated by the magnitude and sign of its ionic charge, can be represented by the term zeta potential. In this paper, the zeta potential represents the difference in potential between the immovable liquid layer attached to the surface of a solid particle and the movable liquid layer in the body of the liquid, and is the result of the tendency of ions on the surface of the particle and within the liquid boundary layer to establish a condition of equilibrium. A high positive zeta potential means that the mineral surface is dominated by cations, a high negative zeta potential indicates domination by anions, and a low zeta potential indicates that the surface is influenced almost equally by cations and anions. In terms of observed quantities the zeta potential is given by the relation [z = 47ruu(300)$ Kx] in which z is the zeta potential expressed in in volts, u the viscosity of the solution in poises, u the velocity of particles in centimeters per second, x the impressed potential gradient in volts per centimeter, and k the dielectric constant of the solution in c.g.s. units. A convenient source for the derivation of the equation is the book by Thomas,6 The term zeta coefficient is an expression coined to denote the difference between the magnitude of the zeta potential of a mineral suspended in solution A, and that of the same mineral suspended in solution B, which consists of solution A and an additional chemical agent, but is at the same pH. For example, the difference between the zeta potential of galena particles in distilled water and that in any chemical solution at the same pH is a zeta coefficient. Or, when the zeta potential of a mineral particle is measured first in distilled water, then in a mixture of water and copper sulphate, and finally in a mix-

Jan 1, 1946

By J. K. Gustafson

Since prehistoric times, gold has been sought for its beauty and its unusual physical and chemical properties. Early in the dawn of civilization it became the ultimate unit of value, and for at least 6000 years it has been used to barter for other commodities. It has been prospected for, treasured and made into works of art and personal adornment. From time to time, it has even been the object of conquest. Because of its predominant role as a basis for money in recent centuries, economists have come to think of gold solely in these terms. Gold, however, has physical and chemical properties that make it one of the most useful metals in the modern world. It is the most ductile metal known. An ounce of it can be drawn into a continuous wire over 35 miles long. It is also so malleable that an ounce of it can be beaten into films 0.00001 in. thick covering 68 sq ft of surface. It has a density of 19.3 and is so heavy that 1 cu ft of it weighs more than half a ton. Gold is nonmagnetic and has a high electric conductivity that is only slightly less than that of silver and copper. Gold is so inert to all the chemicals found in nature that gold coins and jewelry buried beneath the soil or at the bottom of the sea for thousands of years appear to be as bright and perfect as when they were first immersed. Finally, gold has an extremely high reflectivity of both light and infrared rays.

Jan 1, 1971

By T. M. Romslo

"The Keystone and St. George properties are in the so-called Johnson Camp area and adjoin a property that in recent years has become a steady producer of low-to medium-grade copper-zinc ores. The Keystone Copper Co. was active intermittently from 1908 to 1938 and during 1926 to 1937 produced a recorded 1,100 tons of 5 percent copper ore. There is no evidence that ore has been produced from the St. George property.In the Johnson Camp area both igneous and sedimentary rocks ranging in age from pre-Cambrian to Quaternary are exposed. The ore bodies are in the Paleozoic rocks and occur principally in the Abrigo formation, which is composed mainly of limestones and shales. The rocks of the productive zones are metamorphosed and are cut by systems of fractures and faults. Chalcopyrite and sphalerite, the principal ore minerals, replace altered limestones to form deposits locally called mantos and chimneys.Investigation of the Keystone and St. George deposits by the Bureau of Mines included topographical and geological mapping of the surface and the underground workings and diamond drilling from the surface. A total of 10,067.8 feet was drilled in 22 holes. The drilling started November 13, 1947, and was completed August 19, 1948.This report records factual information obtained during the course of the investigation."

Jul 1, 1949

By Louis W. Cope

Many Americans have seen Greenland while flying over it on their way to or from Europe. Few have visited this largest island in the world. Portions of the 20 percent of the territory that are not ice-covered are highly mineralized. Greenland could become very productive if the present interest in exploration increases. The people and Greenland’s history The population of Greenland is 57,000. Twenty percent are Europeans, mainly of Danish decent, while 80percent are native Greenlandic or mixed Greenlandic-European. The native population is the same as the Inuit of the Canadian Arctic. They speak the same language.

Jan 1, 2004

By Jeffrey A. Yonkey, Timothy J. Lutz, Jacob L. Carr, Christopher C. Jobes

"Since 1984, there have been 39 fatalities involving striking and pinning of the operator and other workers by the continuous mining machine (CMM). In January 2015, the U.S. Mine Safety and Health Administration (MSHA) finalized a regulation to require proximity detection systems on all continuous mining machines except full-face machines (MSHA, 2015). Proximity detection systems are designed to stop machine motion to protect miners from striking/pinning hazards. Several MSHAapproved proximity detection systems are commercially available.NIOSH researchers have been involved in the development and testing of proximity detection technology since creating the HASARD system (Schiffbauer, 2002) and have recently conducted research intended to develop more advanced proximity detection technology for CMMs (DuCarme et al. 2013; Jobes et al. 2012; Carr, DuCarme et al. 2013 and Carr, Li et al. 2013). In addition, NIOSH has also conducted research investigating how the signals of a proximity detection system propagate (Li, Carr et al. 2013 and Li, Jobes et al. 2012) and have developed a novel method for determining the location of a personal wearable device (PWD) relative to the magnetic field generators (Carr et al. 2010 and Jobes, et al. 2012).To evaluate the performance of proximity detection systems implemented in industry, NIOSH researchers conducted tests in 2013 on three systems installed on CMMs at three underground mines in Illinois and West Virginia. The results of these tests indicated that, while generally consistent performance was observed, there were opportunities for improving performance. These results were presented at the 2014 SME Annual Meeting (Carr, Lutz, et al. 2014). Since that time, second-generation systems have become available to the industry and are becoming more commonly used.Beginning in early 2014, NIOSH researchers conducted underground testing of these secondgeneration proximity detection systems installed on CMMs. Five tests were conducted on four installations of second-generation proximity detection systems, with one installation being tested twice. The tests were conducted at mines located in Illinois, Virginia and Kentucky with seam heights ranging from 137 cm (54 in.) to 213 cm (84 in.). These tests were conducted using the same test protocol used during first-generation testing, which is summarized in the following section."

Jan 1, 2014

By T. E. Howard

The western phosphate field, comprising parts of Idaho, Montana, Wyoming, and Utah, contains one of the world's largest known reserves of phosphate rock. Although phosphate-rock deposits of good-grade have been known since before the turn of the century and production has been recorded since 1906, real development of this important field did not begin until immediately after World War II. Since then fertilizer-manufacturing facilities using western phosphate rock have been expanded, and three electric-furnace plants for producing elemental phosphorus have been installed, resulting in a rise in mine production from 323,955 long tons2/ in 1945 to 1,653,916 long tons3/ in 1953. Interest in the field is increasing, and it is reasonable to expect that the western phosphate industry will continue to expand. Before 1945 all western production was from underground mines. In that year the first strip mine in the field was started near Montpelier, Idaho,~ and in sub-sequent years a number of other open-pit mines were opened in southeast Idaho and western Wyoming. At present the major part of the production comes from surface mines. Underground mining has continued, and new underground mines have been opened in the field, but recent exploration by operating companies has been aimed primarily at developing additional deposits suitable for low-cost surface mining. Preliminary reserve estimates by the Federal Geological Survey5/ indicate that only a very small part of the total resource may be recovered by surface methods and that the industry eventually must depend largely on underground mining. Because one function of the Bureau of Mines is promoting the conservation and development of the Nation's mineral resources, it is appropriate that research be conducted to develop low-cost maximum-recovery underground mining methods applicable to western phosphate-rock deposits.

Jan 1, 1956

By S. C. Sun, A. M. Gaudin

This paper presents the results of a. study of the relationship of the electrokinetic or zeta potential to flotation phenomena. The relationship is established on the experimental evidence that mineral behavior in flotation and in cataphoresis is generally governed by the chemical properties and amount of the reagents adsorbed at mineral surfaces. Cataphoresisl-5 or electrophoresis is the name given to the movement of a charged particle in a liquid medium under the influence of an applied electric field. Mineral behavior in cataphoresis, as indicated by the magnitude and sign of its ionic charge, can be represented by the term zeta potential. In this paper, the zeta potential represents the difference in potential between the immovable liquid layer attached to the surface of a solid particle and the movable liquid layer in the body of the liquid, and is the result of the tendency of ions on the surface of the particle and within the liquid boundary layer to establish a condition of equilibrium. A high positive zeta potential means that the mineral surface is dominated by cations, a high negative zeta potential indicates domination by anions, and a low zeta potential indicates that the surface is influenced almost equally by cations and anions. In terms of observed quantities the zeta potential is given by the relation _ 4µ(300)² Z= kx in which z is the zeta potential expressed in in volts, µ the viscosity of the solution in poises, u the velocity of particles in centimeters per second, x the impressed potential gradient in volts per centimeter, and k the dielectric constant of the solution in c.g.s. units. A convenient source for the derivation of the equation is the book by Thomas. The term zeta coefficient is an expression coined to denote the difference between the magnitude of the zeta potential of a mineral suspended in solution A, and that of the same mineral suspended in solution B, which consists of solution A and an additional chemical agent, but is at the same pH. For example, the difference between the zeta potential of galena particles in distilled water and that in any chemical solution at the same pH is a zeta coefficient. Or, when the zeta potential of a mineral particle is measured first in distilled water, then in a mixture of water and copper sulphate, and finally in a mixture of water, copper sulphate and xan-thate, we can calculate the zeta coefficient

Jan 1, 1947

By A. M. Gaudin, S. C. Sun

This paper presents the results of a. study of the relationship of the electrokinetic or zeta potential to flotation phenomena. The relationship is established on the experimental evidence that mineral behavior in flotation and in cataphoresis is generally governed by the chemical properties and amount of the reagents adsorbed at mineral surfaces. Cataphoresisl-5 or electrophoresis is the name given to the movement of a charged particle in a liquid medium under the influence of an applied electric field. Mineral behavior in cataphoresis, as indicated by the magnitude and sign of its ionic charge, can be represented by the term zeta potential. In this paper, the zeta potential represents the difference in potential between the immovable liquid layer attached to the surface of a solid particle and the movable liquid layer in the body of the liquid, and is the result of the tendency of ions on the surface of the particle and within the liquid boundary layer to establish a condition of equilibrium. A high positive zeta potential means that the mineral surface is dominated by cations, a high negative zeta potential indicates domination by anions, and a low zeta potential indicates that the surface is influenced almost equally by cations and anions. In terms of observed quantities the zeta potential is given by the relation _ 4µ(300)² Z= kx in which z is the zeta potential expressed in in volts, µ the viscosity of the solution in poises, u the velocity of particles in centimeters per second, x the impressed potential gradient in volts per centimeter, and k the dielectric constant of the solution in c.g.s. units. A convenient source for the derivation of the equation is the book by Thomas. The term zeta coefficient is an expression coined to denote the difference between the magnitude of the zeta potential of a mineral suspended in solution A, and that of the same mineral suspended in solution B, which consists of solution A and an additional chemical agent, but is at the same pH. For example, the difference between the zeta potential of galena particles in distilled water and that in any chemical solution at the same pH is a zeta coefficient. Or, when the zeta potential of a mineral particle is measured first in distilled water, then in a mixture of water and copper sulphate, and finally in a mixture of water, copper sulphate and xan-thate, we can calculate the zeta coefficient

Jan 1, 1947

By H. Hoberg, M. Langen, B. Hamacher

Since the term "abandoned hazardous sites" was first coined in the 1978 environmental report of the Council of Environmental Specialists, a number of different types of technology has been developed in the Federal Republic of Germany for the remediation of contaminated soils /l/. At former sites of the mining industry, such as metallurgical and coking plants whose soil has been contaminated by organic and inorganic pollutants over decades of industrial activity, there is an exceeding necessity for soil remediation. Also, many former locations of metal processing works, battery factories or scrap yards have been contaminated in particular by heavy metals. Wet mechanical soil decontamination has proven successful over the past 10-15 years in the purification of these soils The process goal is the enrichment of the pollutants in certain plant products and the separation of a pollutant concentrate from the decontaminated soil. Table 1 lists the steps of the highly advanced wet mechanical soil decontamination process to achieve this process goal. Table 1 lists both the name of each process step and its goal in terms of a direct separation of the pollutant or the preparation of the soil for subsequent separation steps. For the separation of heavy metals, density sorting and separation techniques utilising flotation were specifically used. The use of chemical auxiliaries such as acids and lye is limited to special cases because these in themselves produce additional environmental impact and the economical effficiency of these techniques compared to conventional methods is lowered by supplementary process steps for water purification. The subject of this presentation is to consider how soil decontamination processes can be effectively improved through a description of the material properties of soils contaminated by heavy metals, and through carrying out basic investigations about the adsorption of heavy metals. Soils of different origins, especially those from former mining and metallurgical sites, were used for the experiments.

Jan 1, 1995

By C. R. Austin

Tan investigation described in this paper deals with the development of high-temperature alloys of the Konel series over a considerable period of time at the Research Laboratories of the Westinghouse Electric and Manufacturing Co. The word "Konel" has been coined to designate a class of alloys which are essentially nickel-cobalt-iron with other elements added, usually in small quantities. Most of these alloys contain titanium, usually about 2.5 per cent. The main consideration related to strength at high temperatures but the thermionic characteristics of the alloys was also of considerable importance. It is, however, with the mechanical properties at elevated temperatures that we are herein concerned. Much attention has also been devoted to their age-hardening characteristics. There is little need to stress the utilitarian aspect of this subject, as it has been discussed frequently. Alloys exhibiting superior properties at normal or elevated temperatures rapidly find many suitable applications. There may be some question, however, as to what constitutes a "superior alloy, " or an alloy that may have good service possibilities at high temperatures. The problem is complex and various means have been employed to predict the useful life that may be expected of a material. In recent years the "creep limit" has been used as the best means of evaluation. Such tests necessarily are prolonged and hence collection of data is very slow. In a general survey of many alloys therefore the creep test is not desirable and recourse must be had to much shorter time tests in order more rapidly to select alloys which appear to show promise. For this reason the present survey has been made using the high-temperature tensile test and a bend test developed by Howard Scott.1 In the tensile test the conditions have been standardized for all tests, so that values obtained are at least comparable, one alloy with another, although the absolute values recorded merely indicate the mechanical properties at the given temperature under a definite rate of loading.

Jan 1, 1931

By Will Mitchell

The classical definition of a beneficiation engineer as one who treats an ore in order to separate and discard worthless fractions by essentially physical means is obsolete. Technology in the profession has advanced so rapidly during the last two or three years that educators have not been able to coin definitions to keep up with the pace. In the past some people have hesitated to include leaching or even agglomeration as minerals beneficiation, because of the major chemical changes involved. This view has fallen by the wayside, especially because a majority in the profession have become actively involved in extraction and pyro processes that go far beyond the original definition of mineral dressing. To say that there is a great revival of interest in leaching is putting it mildly, for the uranium business, like the gold business, now depends almost entirely on leaching. This revival of leaching, long overdue in mineral engineering, has been stimulated this year, especially as a result of the relaxation of security restrictions surrounding the recovery of uranium from its ores. It has brought new unit operations to minerals beneficiation, namely ion exchange and solvent extraction. These operations have appeared as resin-in-pulp, solvent-in-pulp, and liquid-liquid systems. In many cases these leaching and separation procedures, now reaching the production stage, have been engineered by minerals beneficiators. The trend toward leaching has also had impact on the technology of beneficiating other nonferrous minerals, especially copper, manganese, columbium, tantalum, nickel, cobalt, titanium, and the rare earths.

Feb 1, 1956

By J. Y. Foley

Platinum-group elements (PGE) are preferentially associated with chromian spinels, including high-iron chromite, magnesian-chromian hercynite, and chromian magnetite in clinopyroxene-rich upper stratigraphic portions of the Tonsina ultramafic complex in southern Alaska. Ratios of Pt:Pt+Pd are proportional to chromium content in the associated chromian spinels. The maximum PGE content of geochemical rock samples from Dust Mountain is greater than 20.000 ppb (>0.6 oz/ton) with minor gold values. The maximum PGE content of tabled chromite concentrates is 3.430 ppb (0.1 oz/ton) at Dust Mountain. 1.029 ppb (0.03 oz/ton) at Sheep Hill, and 1,749 ppb (0.051 oz/ton) at Bernard Mountain. High-iron chromite at Dust Mountain yields tabled chromite concentrates with Cr:Fe ratios between 0.5 and 1.2. Lower PGE contents are found in more chromium-rich chromitites from Sheep Hill and Bernard Mountain that yield concentrates with Cr:Fe ratios between 1.0 and 2.8. Platinum-group minerals include amalgams. arsenides. PGE alloys, and sulfides. These minerals are between 3 and 40 microns in size and are concentrated along grain boundaries and fractures of metasomatically and hydrothermally altered chromian spinel grains.

Jan 1, 1987

By M. N. Shetty, A. C. D. Chaklader

RECENTLY, it has been demonstrated that a considerable densification and interparticle bonding can be achieved if a pressure is applied to a powder compact while the material of the compact is undergoing either a decomposition reaction' or a polymorphic transformation.' The term "reactive hot pressing" has been coined to identify this process in which a phase change is combined with pressure to achieve interparticle bonding. This process is based on a principle which postulates that there is an enhanced reactivity and mobility of the molecular species at the phase-transformation temperature and this effect is utilized for interparticle bonding in powder compacts. This note summarizes the results obtained in an attempt to utilize this technique to produce ceramic-metal composites. In this case, a decomposition reaction of a compound (which after decomposition yielded an oxide) was used to achieve interparticle bonding in ceramic-metal composites. The reactive hot pressing was carried out in a Phillips induction heating unit, using either a graphite or a high-temperature steel die which functioned as both the susceptor and the hot-pressing component. The die was heated to the desired temperature in a helium atmosphere. All cermets produced by this technique were based on alumina as the ceramic phase. Different metal phases such as iron, copper, and chromium were used to study the effect of varying the metal phase on the properties of the composite. a Mono-hydrate (Boehmite) was mixed with different proportions of metal powders (-325 mesh) in dry condition in a mortar and pestle. No special precautions were taken for proper mixing. The mixtures were then compacted into a cylindrical form having an approximate dimension of 1 cm in diameter and 1 cm in height. For this compaction an ordinary

Jan 1, 1965

By H. W. Gillett, A. E. RHOADS

In its study of methods for reducing metal losses in the non- ferrous metal industry, the Bureau of Mines has conducted a long series of experiments on electric brass melting and collected much data on the experiments of others. Reports bearing on this work that have already been published by the Bureau of Mines are Bulletin 73, "Brass-furnace practice in the United States," and Bulletin 77, "The electric furnace in metallurgical work." A comprehensive report describing the design and operation of all types of electric brass furnaces and showing their performance in experimental tests on a commercial scale is in course of preparation. However, commercial tests of several new and promising types of furnaces are still under way, the results of which should be included in any general discussion of the subject. For this reason it has seemed desirable to issue a preliminary bulletin giving the data on a type of furnace developed in one stage of the bureau's work.

Jan 1, 1918

By Joe Shoemaker

Automated Spot Generation ? No Operators below the Highwall ? No Operator Wear and Tear ? Reduced Swing Time ? Single and Double Sided Loading ? Minimized Bench Width

Aug 1, 2013

By J. A. Singmaster

IT will perhaps be wise to define my terms in begin-ning to talk about my subject, especially so where the popular and commercial terminology are as con-fused as they are in the case of zinc. While our French friends know zinc by its true name, and we find Balzac, Daudet, and other literary celebrities using it correctly in their novels, it is quite the contrary in English, particularly here in America. The quotation of a definition for zinc recently appearing in one of our leading technical magazines, "zinc is the place where they wash the dishes," will emphasize the difference. Zinc suffered in the first place by becoming an article of commerce long after its alloys with copper were in common use under the name of brass. Then again, when the art of zinc coating iron and steel objects was commercialized, we called it galvanizing, which is really a meaningless term. The French and Germans use the obvious terms-zinguerie and verzinken-for the opera-tion. Since these two uses of zinc, brass making and galvanizing, have been by far the largest consumers of zinc, is it any wonder that the popular knowledge of zinc is as vague as it is? In fact, since the disappear-ance of the sheet of zinc along with the parlor stove, the zinc-lined bath tub and refrigerator, there has been little popular contact in this country with the undis-guised metal zinc. On the Continent, where zinc has been used for over a hundred years under its real name, particularly for roofing and building purposes, the situ-ation is quite different. It is quite refreshing to turn for a moment to the contrast offered by my friend, Dr. Merica's specialty, nickel. They put 2 or 3 per cent of it into steel, and we have nickel-steel, or a larger amount into an alloy, and we have nickel-silver. To be sure there is no silver there, but what need that matter, nickel is used in the alloy and is first in the name. They plate with nickel and call it nickel-plating, no galvanizing about that. And, finally, they take that noble coin which admits us daily to underground New York, composed of three parts of copper and one part nickel, and get away with nickel as its popular name.

Jan 6, 1927