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By C. W. Elder

"INTRODUCTION This report describes a method of horizontal drilling in an oil-producing formation underlying a 400-acre, approximately square plot of land in the Franklin Heavy oil field in Sugar Creek Township, Venango County, Pa. The method, which was developed on two previous projects in Ohio, 3/ consists of sinking a shaft to the bottom of a shallow oil sand and drilling holes in a general horizontal plane outward from the chamber in a pattern similar to that of the spokes of a wheel. The project was undertaken by the Venango Development Corporation in an attempt to find an efficient method of recovering oil from partly depleted sand formations.The Venango Development Corporation is composed of the following oil-producing and oil-refining companies and individuals: South Penn Oil Co., Forest Oil Corporation, Kendall Refining Co., Minard Run Oil Co., Quaker State Oil Refining Co., The Pennzoil Co., Alliance Oil Corpo¬ration, United Refining Co., Franklin Creek Refining Corporation, Canfield Oil Co., Pennsylvania Refining Co., Page Oil Co., Freedom Oil Co., D. W. and D. S. Grant, and J. P. Herrick, C. M. Davison and N. V. V. Franchot. Engineering features of the project were supervised by a committee off three engineers A. J. Saxe, chairman, W. M. Shoemaker, and C. N. Pfohl, who supervised the excavation of the shaft and the drilling of the first two holes by alternately spending a week at a. time at the project. The drilling method was under patent license from Leo Ranney, who served as technical advisor to the Venango Development Corporation; in addition, he furnished the design for the shaft and work chamber."

Sep 1, 1944

By T. Cantwell, N. C. Rasmussen, H. E. Hawkes

Beryl is a mineral that may be difficult to distinguish from quartz by casual field inspection. The easily recognized green color and hexagonal crystal form of coarse-grained beryl are by no means universal, even in beryl from pegmatitic deposits. If it occurred as a fine-grained accessory mineral in an igneous rock, it would almost certainly escape detection unless samples were submitted for petrographic or chemical analysis. There may be substantial deposits of some beryllium mineral, other than beryl, that has been overlooked because that mineral also closely resembles the common rock-forming minerals. A reliable and simple method of identifying beryllium minerals and determining the beryllium content of a rock would be helpful in exploration. This article describes preliminary experiments in applying nuclear reaction to the qualitative identification of beryl and to the semiquantitative determination of the beryllium content of rock samples. Gaudin,1,2 the first to apply a nuclear reaction in detecting beryllium minerals, developed a method that irradiates the sample with gamma rays, which react with beryllium nuclei to produce neutrons. The neutrons are then measured with standard equipment. The cross section for this reaction is about 1 millibarn. The cross section is a measure of the probability that a reaction will take place, for example, between a beryllium nucleus and an incident gamma ray or alpha particles.3-5 At 1-millibarn cross section for the reaction, satisfactory performance required a source strength of the order of 1 curie (3.7 x 10"' disintegrations per sec, where each disintegration releases one or more gamma rays). The reactions will not take place if the gamma radiation is below a minimum energy, in this case 1.63 mev. The size of the source and the energy of the radiation made heavy shielding necessary for these experiments, both to reduce the background count of the neutron counter and to safeguard personnel. The original discovery of the neutron by Chad-wick in 1932 resulted from experiments with another nuclear reaction, induced by bombarding beryllium with alpha particles in which the products are carbon-12 and neutrons. The equation for this reaction is as follows:' " ,Be" + ,He'? 6C12 + 8,n' [1] re-particle neutron In the above nuclear equation (Eq. 1), the sub- script number indicates the number of protons in the nucleus (the atomic number) and the superscript the total number of neutrons and protons (approximately the atomic mass). For the alpha-neutron reaction the cross section is about 250 milli-barns, or 250 times that of the gamma-neutron reaction used by Gaudin. The positively charged alpha particle is repelled by the positive charge of the beryllium nucleus; it must, therefore, have a certain minimum energy in order to approach close enough to the beryllium nucleus to react. For reaction with the beryllium nucleus, the lower limit of the alpha-particle energy is 3.7 mev. The alpha-neutron reaction, with polonium-210 as an alpha source, was selected for the present experiments. Alpha particles are emitted by polonium-210 at 5.30 mev, which is adequate for the reaction with beryllium. Furthermore, this isotope of polonium emits alpha particles with negligible associated gamma radiation, thus eliminating the necessity of shielding. The half-life of polonium-210 is 138 days. Inasmuch as alpha particles carry a possible charge and are large compared with most nuclear particles, their energy is rapidly dissipated in passing through matter. Their range in standard air is 3.66 cm,3 and they penetrate only a few tens of microns into a mineral sample. The short range in air can be minimized by preparation of a flat sample surface that can be brought very close to the alpha source during analysis. On the other hand, short range of alpha particles in air lessens the radiological health hazard and makes it possible to use this method without shielding. It must be emphasized, however, that the alpha emitters are potentially very dangerous if they enter the human body. Polonium must be handled with extreme caution. The literature has reported experiments on the yield of neutrons from reaction of alpha particles with beryllium nuclei. Feld" reports that in intimate mixtures of polonium and beryllium, 3 x 106 eutrons per sec are produced per curie of polonium. Elsewhere in the same reference it is stated that a sandwich-type source yields about one third as many neutrons as an intimate mixture. A table of neutron yields for full energy polonium alpha-particles on thick targets as reported by Anderson7 is the basis of Table I. From Table I it can be deduced that the elements most likely to interfere, i.e., those that also produce neutrons when bombarded by alpha particles, are boron and fluorine. These data also show that it will probably not be possible to determine very small quantities of beryllium in rocks because of the masking effects of the major elements, sodium, magnesium, and aluminum. The neutrons emitted in the alpha reaction are detected by another nuclear reaction. Either of the

Jan 1, 1960

By Tony Brunger, Abid O. Adekunte, George Munteanu, David Greentree

A number of novel solutions have been proposed in recent years as alternatives to props and tie-backs in deep excavation support e.g. Adekunte (2008), Deschamps et. al. (2008), Adekunte et al. (2010) and Adekunte (2014). A number of these non-standard restraining solutions involve the construction of permanent or temporary vertical or raking buttress piles that are rigidly connected to the excavation support wall at regular intervals along the wall run. This paper chiefly focuses on the design and construction of twin-vertical buttress piles as restraining systems behind or in front of embedded retaining walls. The system essentially relies on the push-pull mechanism that develops between the twin piles, to maintain the overall stability of the excavation support. The paper’s main areas of concentration include; finite element modelling, geostructural design, construction procedure, instrumentation and monitoring that are associated with the application of twin- buttress pile systems. These are supported with project details of three recently completed high-end luxurious residential developments in Greater London, England, on which the twin-buttress pile system was used to restrain the excavation support walls for the basements on the sites. The mode of application of the system varies across the three sites. While the system was adopted as a long term solution behind the retaining wall on one of the sites, it was designed and constructed for temporary use in front of the retaining walls on the other two sites. Instrumentation and monitoring results from all the sites show the non-traditional system to be safe and effective, whilst having significant beneficial effects on construction programme, sequence of works and project cost.

Jan 1, 2018

By R. D. Stewart

Paper presented at the conference: Risk assessment in the extractive industries, held in Exeter, UK, 23-24 March 1994, and first published London: IMM, 1994, preprint volume, 18pp., 5 refs. A seismic risk assessment method has been developed for application to rockburst prone deep-level mining sites which have sufficient seismic coverage. The technique utilises several seismic hazard parameters simultaneously and assesses the seismic risk on a daily basis according to the individual levels of these parameters. Critical levels are determined from investigation of the long-term behaviour of the parameters in relation to recorded potentially damaging seismic events. The method has been applied to a data set comprising 15 months' worth of seismic data, with encouraging results

Aug 1, 1995

Mintek now offers a service for the accurate measurement and analysis of air pollution in South Africa. 'The deteriorating air quality and general degradation of the environments in industrialized and urban regions of South Africa have been of concern for more than a decade', says Mintek's Dr Johann Engelbrecht. 'The accompanying effect on health, visibility, and damage to property and the environment have prompted the public, authorities, and industry to take appropriate action. A recent study conducted by the Medical Research Council on schoolchildren in the Vaal Triangle, clearly demonstrated the relationship between the deficient quality of the air in that area, and the resultant respiratory diseases.

Jan 1, 1996

By L. A. Cramer

South African platinum mines produce the world?s majority of platinum metal that is used in autocatalysts and jewellery. As the platinum market is forecast to grow at healthy rates into the future, the South African producers, Anglo Platinum, Impala, Lonmin and Northam, are planning to expand in the next decade. Furthermore, a number of smaller producers who are accessing other mineral rights are entering the buoyant market. The South African platinum mines have traditionally exploited the Merensky Reef of the Bushveld Igneous Complex (BIC); however, the mining of this reef is reaching depths that require significant vertical shaft systems and costly refrigeration for access to the orebodies at deeper levels. In the past decade all of the producers have begun to mine the less attractive UG2 reef because of its cheaper mining costs. This UG2 reef contains significant quantities of chromite with typically a chrome-to-iron (Cr/Fe) ratio of 1.35. UG2 ores can contain between 10 and 25% Cr2O3dependingupon the reef width and the selected mining method. It is relatively cheap and easy to extract a portion of the chromite from a platinum concentrator tailings stream at a grade of between 40?42% Cr2O3. However, it is only in recent years that some ferrochrome producers have begun to source some of their chromite from the tailings of platinum producers. South Africa is also the world?s largest single producer of ferrochrome and supplies much of the world?s stainless steel producers and thus the growing market for their product. As the traditional sources of high Cr/Fe ratio ores have been depleted at the shallow economic depths and thus have become more expensive sources of chromite, technical developments have improved the ability to use fine chromite economically to make acceptable grades of ferrochrome. Thus UG2 fines are now becoming possible cheap sources of acceptable feed to the ferrochrome industry. The abundance of feedstock for ferrochrome production and the lessening dependence on mined material will impact upon the structure of the ferrochrome business in South Africa. With continued platinum mining from UG2 reefs, South Africa is set to remain highly competitive in the world?s ferrochrome/stainless steel industry.

Jan 1, 2004

By S. J. McCarroll

Fig. 1—The belt shown at right carries filter cake to mixing station over calciner. Crude ore conveyors appear in right background. THE Three Kids mine, some six miles east of Henderson, Nev., is in a typical southwest desert area, with high dry summer heat and cool to cold winter seasons. The manganese deposit was located during World War I.' During this period 15,000 to 20,000 tons of ore assaying up to 41 pct manganese were shipped. Interest in the deposit was not revived until the middle thirties, when experiments on the ore were initiated. Test work indicated possible recovery of only 70 pct by flotation, but in 1941 additional work was done at the Boulder City pilot plant of the U. S. Bureau of Mines and also by M. A. Hanna Co. As a result, the Manganese Ore Co. was formed and a plant utilizing the SO2 process was constructed. Numerous operation difficulties ensued, and the plant. was closed when the manganese situation in the country eased. In 1949 Hewitt S. West initiated negotiations to acquire the plant. In 1951 Manganese, Inc., was formed and contract entered into with the General Services Administration to supply 27 million units of metallurgical grade manganese in the form of nodules to the national stockpile. A second contract was made to upgrade 285,000 tons of stockpile ore. Test work was undertaken by the Southwestern Engineering Co. and likewise by the Boulder City pilot plant at the U. S. Bureau of Mines. Results obtained indicated the commercial feasibility of the flotation process. Construction of the plant, which is shown in Figs. 1 and 2, was started in June 1951, and operations on a break-in basis began in September 1952. Apart from the usual starting difficulties two major disasters caused serious setbacks, one a kiln failure in February 1953, and the other a fire that destroyed the flotation building in June of the same year. The nodulizing section of the plant resumed operation in November, and the flotation section in January 1954. The ore minerals are chiefly wad,* with minor amounts of psilomelane, and occur in sedimentary beds of volcanic tuff. The ore is overlain with beds of gypsum which outcrop or may be covered with surface gravel. Intermediate beds of red and white tuff occur frequently with lenses of red and green jasper and stringers of gypsum and calcite. Small amounts of iron are present; lead content averages about 1.0 pct and minute amounts of copper and zinc are found. Barite, celestite, and bentonite are present. Since these are made up of minute asicular crystals, moisture content is very high, averaging about 18 pct. Ore reserves have been estimated at 3 million tons averaging 18 pct Mn2 and up to 5 million tons after grade is dropped to 10 pct Mn. A good part of the orebody was stripped of overburden by the previous operating company . Approximately 50 pct of the ore, representing more than 60 pct of the manganese, can be mined by open-cut methods. A system for underground min- . ing has not yet been decided on. Open-cut mining with benches of 20 ft has proved satisfactory. Although the ore is soft and appears dry and dusty it has a certain resilience, probably due to the porosity and moisture which makes drilling and fragmentation difficult. Wagon drills have been abandoned in favor of the Joy 225-A rotary drill which will put down a 43/4 -in. hole at the rate of 2 ft per min. Holes are spaced in a pattern with 8 to 9-ft centers. Forty percent powder has been used, but better breaking to 2-ft size is obtained with low velocity bag powder of 30 pct strength. Loading is done with one 21/2-yd shovel, and cleanup follows with one D-7 bulldozer. The ore is hauled with Euclid trucks about 1000 ft from the pit to a blending pile, where the daily mine production is spread in layers by bulldozing until approximately one month's mill feed is accumulated. A new pile is then started and mill feed is drawn from the first pile by one 13/4-yd shovel and Euclid trucks, with a haul of approximately 500 ft. Mining is performed by an independent contractor with engineering and supervision by the company staff. Early test work indicated that the manganese could be floated with soap, a wetting agent, and fuel oil to give a recovery of better than 75 pct with a grade of 43 pct Mn. The concentrate when nodulized with coke would upgrade to 46 pct Mn or over, and the lead volatilized to 0.6 pct residual.

Jan 1, 1955

The May General Meeting of the Institute was held in Kelvin House, Johannesburg on 20th May, at 4.30 p.m. Mr V. C. Robinson (Vice-President) was in the Chair in the absence, overseas, of the President, Mr J. K. E. Douglas. There were also present 16 Fellows: Messrs J. A. Adamson, R. S. J. du Toit, J. A. Drummond, D. F. A. Grave, T. L. Gibbs, G. H. Grange, D. V. Howat, P. H. Kitto, Dr P. J. LIoyd, Messrs B. H. L. Leach, J. de V. Lambrechts, Dr J. T. McIntyre, Messrs C. S. MacPhail, P. W. van Rensburg, S. G. Taussig, W. S. Rapson. Six Members: Messrs E. L. Atkinson, R. Hemp, Dr J. Martinson, Messrs A. H. Munro, G. J. van Jaarsveld and J. H. Qwilliam. Two Associate Members: Messrs B. H. van Rensburg and H. Triiter. Four Visitors: Prof J. E. Kerrich, Dr G. K. Sluis-Cremer, Messrs D. Kisbey-Green and L. W. Isserow. For Secretariat: Mrs S. de Gersigny. Total present: 27. OBITUARY The Vice-President: "It is my sad duty to announce the death of Stephen Ring, a member who joined the Institute in ]961, and passed away on the 31st of December, 1969. I would ask you all to rise and observe a moment's silence. Thank you." MINUTES The Vice-President: "May we confirm the minutes of the Special General Meeting and Monthly General Meeting, held on 20th February, 1970, as published in the April issue of the Journal?" MEMBERSHIP The Vice-President: "I have much pleasure in announcing that the names of the undermentioned candidates, having been published in accordance with By-Law 5 2.2, Council has elected them to membership of the Institute in the following grades: Fellows: Denis Ian Field, Arthur Cecil Waiter Comyn, John Hall, Leon VercueiI. Members: Jan McLellan Vosloo, Jan van Velze. Graduates: Richard Darnley Beck, John Edward Andrews, Roderick Nowell Randell. Associates: Alexander Duncan Ross, Ian James Terrill. Students: Hendrik Jacobus Oostenwald Prins Smith, Graham Peter Gooding, Rudannes Raath Homan. "I welcome the newly, elected members to the Institute." GENERAL BUSINESS The Vice-President: "Are there any matters which you wish to raise under 'General'? There being no matters to raise under 'General', we will proceed to the next item on the Agenda." PAPER FOR PRESENTATION The Vice-President: "It is my pleasant duty to call on Dr du Toit to deliver his paper, entitled, 'The functional relationship between dust hazard and the rate of collecting funds to pay compensation for pneumoconiosis'." After the presentation of the paper (published in the March Journal) the Vice-President said: "This paper is a very important addition to the considerable volume of work applications on this subject of pneumoconiosis. The disease, in all its various forms, has received attention from many, many great men, both in the medical world, and engineers. The fact that there is this big volume of publications of literature on it still doesn't mean that we can get anywhere beyond the old, simple injunction, that the prevention of pneumoconiosis does not depend on compensation, levies or anything else. It simply depends on allaying dust as quickly as possible. "This paper, however, is another scientific landmark and I think, in a cold and dispassionate way, it sets out some important points in this whole subject of the relationship of the levy - the money of compensation to the dust which causes it. "I have, personally, very little to criticise in this paper but when I listened to Dr du Toit's final conclusions, I wondered whether the words, 'Within the data available', aren't the key to this whole situation. I agree that he has demonstrated a workable relationship between the current industries for levy and dustiness, but among the factors which he lists as being important, I know that there is one which is missing. This is extremely difficult to evaluate. It's a factor which has destroyed, on so many occasions, the work which has been done by so many genuine, intent, honest people working in this field, and this is this unknown factor, this hidden factor of political opportunism, which has so often played a very important part in pneumoconiosis compensation. "How many of us have seen the grubby, grasping fingers of power-mad demagogues, and I can name them for you - but I won't - and also the blatant vote-catching of certain politicians interfering in this field. How, at the end of all that, the poor scientist, the poor dedicated man in the Mines' Department, who has to write the law of compensation, can operate, I do not know. "From this picture the ordinary layman recoils in horror. Among the casualties in this particular war, which has been fought over so many years, I am perfectly certain, are some of the criteria of certification, especially in '56/,57, when that extraordinary condition, known as 'pulmonary disability' was introduced. I am sure there were casualties then, in the criteria of certification. "Nevertheless, this paper is a worthy addition to the long list of scientific work done on this so-important

By K. M. Stone, N. J. G. Masson, A. C. Woollett

The Jabali zinc deposit, in Yemen, contains at least 9.4 Mt at a grade of 10.7% zinc, 2.2% lead and 77g/t silver. The zinc occurs as smithsonite with minor hydrozincite. The Jabali ore does not produce a zinc concentrate of sufficient grade to be acceptable to conventional smelter/refineries, and it has been necessary to formulate a less conventional development plan. This involves the construction of a mine and concentrator at Jabali and a metal production facility using a new flowsheet designed specifically for the treatment of oxide material, at Yanbu, in Saudi Arabia. In order to give the facility the necessary economies of scale, the Jabali concentrate will be supplemented by feed from other deposits, this may be either oxide or sulphide material. The paper outlines the geology and proposed mining and treatment operations at Jabali, the flowsheet for Yanbu and presents preliminary costs for both operations

Jan 1, 2002

By R. F. Abernethy

Recent investigations in the United States and in other countries have produced considerable information on the nature and occurrence of minor elements in coal. The possibility of recovering certain elements, particularly germanium and uranium, from coal ash and other coal products has received considerable attention. Some flue dusts are potential sources of germanium, and certain lignite deposits are potential sources of uranium, but industrial recovery of these elements has been limited to small quantities for technical and economic reasons. Considering the large amount of coal mined annually, a small percentage of a rare element may have industrial significance if an economical method of recovery can be developed. In 1944 information on the occurrence of rare elements in coal was reviewed in Bureau of Mines Technical Paper 669 (46).3 This report is a revision of that paper with the view of summarizing published information available for United States coals, and pertinent information concerning coals of other countries. Selected references from the original paper are retained. New references do not include all preliminary reports when more permanent literature describing complete projects is available. Consequently, the list of references should not be considered complete.

Jan 1, 1963

The eighth annual RMCMI Mine Rescue Evaluation was held during the 1999 Institute convention at the Crested Butte Marriott Resort, Colorado. [ ] Elliott Tsosie, Mary Rowell, Janna Aune, Guy Horton, Art Saenz and Bill Balaz were pleased with the 1999 Mine Rescue Program, The Mine Rescue committee is but one of 17 volunteer committees; this one co-chaired by Bill Balaz, Elliott Tsosie and Janna Aune. There were three evaluators, Art Saenz, Western Environmental; Mary Rowell, ProCare and Guy Horton, Horton Rope Rescue. Nine teams participated and brought 89 participants, 26 spouses, nine children and five teens. The teams were BHP LaPlata, BHP Navajo, BHP San Juan, all from Farmington, NM; Bridger Coal Co., Rock Springs, WY; The Coteau Properties Co., Beulah, ND; Northwestern Resources, Jewett, TX; Powder River Coal Co., Gillette, WY; Solvay Minerals, Green River, WY and Western Energy Co., Colstrip, MT. To observe were members from Centralia Mining Co., Centralia, WA. [ ] Evaluators: Mary Rowell, Guy Horton &Art Saenz The three professional evaluators provided challenging scenarios for the Mine Rescue participants on the grounds of the resort property. Some attending convention were alarmed to see stretchers with "victims" and phoned the hotel switchboard to report the catastrophe. Team members had no prior knowledge of what the scenarios might be and derails were provided only as they arrived at the scenario location, with one exception. Seven to ten or more articipants make up each team. Some teams also ring an alternate and team trainer. For identification purposes, the "victims" wore white shirts emblazoned both front and back with a red VICTIM designation. There was a staged demonstration by three response teams who had not previously worked together. This was enacted on the convention floor following a Technical Session meeting attended by about 200 members. Three response teams from BHP's Navajo and San Juan Mines together with Coteau Properties' Freedom Mine provided a demonstration of their response skills. For never having worked together before, they presented a very professional enactment. This is described at length in the Welcome Session copy. Training sessions were held Saturday and Sunday to enable the teams to prepare for the scenarios. A swap meet was Saturday evening for teams to swap hats, shirts, belt buckles, stickers etc. Each participant received a royal blue golf shirt and ivory cap with royal blue bill. Culmination of the Mine Rescue program was a Tuesday morning Awards breakfast when teams were presented with jade acrylic plaques. [ ] Teams participating in the Mine Rescue Evaluation received trophies on Tuesday morning. The captains above represent BHP-La Plata, BHP-Navajo, BHP¬San Juan, Bridger Coal Co., The Coteau Properties Co., Powder River Coal Co., Solvay Minerals, and Western Energy Co. Sponsors who contributed financially to the 1999 Mine Rescue program were Balaz & Associates, CMC, Civil Constructors, Colstrip Electric, Farmington Fire Equipment & Safety, Fisher Safety, Flanders Ellctric Motor Service, Magnum Metals, Richard Palmtag, Rocky Mountain Electric Motors, Sedona Consulting and Western Water Consultants. [ ] Evaluator Art Saenz likes to have the upper hand and will take whatever steps necessary to get it.

Jan 1, 1999

By Kerry J. Stanaway, Thomas E. Garnar

Titanium was discovered in 1791 and, four years later, was named after the Titans of Greek mythology. Titanium metal was first made in 1910, but was not used commercially until the 1950s when it was nick-named The Wonder Metal of the Age. The first titanium dioxide (TiO2) white pigments were produced commercially in 1915; more than 90% of the titanium minerals produced in the world today are used in the manufacture of white pigments. The remaining 10% are used to manufacture titanium metal and other uses such as welding rod fluxes. Titanium mineral mining began in the United States between 1880 and 1900 in Chester County, Pennyslvania. Rutile from a deposit near Roseland, VA, was mined in 1901. The use for the rutile was limited to production of a few titanium chemicals and for coloring ceramics. Larger scale mining for ilmenite, rutile, and zircon began in Florida to provide chemical materials for use in World War I in 1918. This mining ended in 1928. Large scale mining of titanium minerals in Australia began when Benick, Anderson, and Porter (later called Tamco) started mining the beach sands at Yamba in New South Wales in 1935. Ilmenite production from beach sands in the State of Kerala in southwestern India also began in the 1930s. The 1940s saw many changes in titanium mineral mining. Extensive deposits of ilmenite and ilmenite-bearing iron ores were discovered in eastern Quebec. The Pigments Department of E.I. Du Pont de Nemours & Co. lost their high grade Indian ilmenite supply after World War II began, and they were forced to use lower grade ilmenite from National Lead's (now NL Industries) Sanford Lake Deposit, near Tahawus, NY, in the Adirondack Mountains. At the end of the war, Du Pont undertook an intense search for a domestic ilmenite source. With the cooperation of the US Bureau of Mines, Du Pont geologists found a very large deposit east of Starke, FL, in 1946. In 1948 Du Pont entered into a contract with Humphreys Gold Corp., who operated a heavy minerals mine near Jacksonville, FL, to construct a plant and operate it for a period of ten years. The plant started up in 1949 and operated under Humphreys' management until the contract expired in 1958. Du Pont has operated the plant since that time. In 1956, a second plant was designed and built by Du Pont a few kilometers northeast of the town of Lawtey. The 1960s saw titanium mineral production expand in the southeastern US with Humphreys' contract mining Du Pont's ore body at Folkston, GA. In the early 1970s. American Cyanamid and Union Camp Paper Co. formed a joint venture company, Titanium Enterprises (TE), to mine and separate titanium minerals from Union Camp's ore deposit southwest of Green Cove Springs, FL. In 1975 the TE plant was shutdown and later sold to Associated Minerals (USA), Inc. (AMC), a subsidiary of Renison Goldfields Consolidated Ltd., an Australian company. It now operates under the name RGC (USA). Mineral production grew in the 1970s with the development of extensive heavy mineral deposits at Eneabba in Western Australia and Richards Bay in the Republic of South Africa. The 1980s saw the construction of a very large ilmenite mine and synthetic rutile processing plant in the state of Orissa southwest of Calcutta, India. At the same time, concern for titanium mineral shortages expected by the end of this century, gave rise to a flurry of exploration activity during the mid 1980s. As a result, large deposits were found in Virginia and North Carolina. New deposits were also discovered in Australia. Fig. 1 shows the distribution of world titanium deposits and mines. The world TiO, production capacities are given in Table 1.

Jan 1, 1994

By E. Martinez

Samples of chrysocolla, a hydrated copper silicate, from several sources were submitted to differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). Pure samples of chrysocolla are difficult to obtain, but comparison of the thermograms revealed that certain reactions occurred in all the samples and it is believed that these are due to chrysocolla. Endothermic reactions occurred at 50' to 175°C, 350° to 650°C, and 980° to 1100°C each of which caused a weight loss. The first was due to loss of absorbed water, the second to a dehydroxyla-tion, and the last to conversion of cupric oxide to cuprous oxide. In addition, two exotherms were detected at 685° to 695°C and 935° to 950°C. Infrared spectra of heated samples indicated the exotherms were due to changes in the Si-O bonds leading to the formation of cristobalite. The results suggest that thermoanalysis may be a more sensitive and reliable method for detection and identification of chrysocolla than X-ray diffraction, infrared spectroscopy, or optical techniques. The recovery of copper from oxide ores has been the subject of much research in recent years. One of the principal oxide copper minerals is chrysocolla, a hydrated copper silicate. The information available indicates that it has widely varying properties depending on the origin of the sample. Chrysocolla usually is found associated with cuprite, malachite, azurite, and native copper. Most of these other minerals are recoverable by present day flotation practice, but chrysocolla is lost in the tailings.1,2 Reagent combinations that are successful in laboratory chrysocolla flotation with ore from one source have been found to be ineffective with another. 3 The copper segregation process offers an altemative to beneficiation of oxide copper ores.4'5 The process is of particular interest in processing ores that cannot be treated by conventional hydrometal-lurgical methods because of high acid consumption.6 Fuller understanding of the properties of chryso- colla may prove of value in the search for improvements in both the flotation and segregation processes. Chrysocolla samples from Arizona, Nevada, Chile, Australia, and South Africa were studied by differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). In addition, a sample from Miami, Ariz., was submitted to X-ray diffraction, infrared spectrophotometry, and surface area determination. EQUlPMENT Differential thermal analysis (DTA) detects, amplifies, and records exothermic-endothermic reactions occurring in a sample as its temperature is raised at a constant rate, usually 10°C per minute. A unit made by the Robert L. Stone Co. was used in this study. The tests can be run if desired with a gas streaming through the sample. A thermobalance records weight losses or gains in a sample as its temperature is raised at a uniform rate. The gravimetric analyses (TGA) were run on a Chevenard thermobalance converted electronically for graphic recording. A heating rate of 5°C per minute up to 1100°C was used in these tests. A Perkin Elmer Infrared Spectrophotometer, Model 221, was used with sodium chloride optics obtaining IR spectra in the 2 to 15 region. A pressed pellet technique with potassium bromide was used in preparing the samples. DESCRIPTION OF SAMPLES Chrysocolla is found in the oxidation zones of copper deposits commonly associated with malachite, azurite, and limonite. It is described as varying in composition and in color from bluish green to brown or black. Inclusions of other minerals are usual so chemical analysis of chrysocolla samples may be suspect. However, it is considered by many to be a solid solution of CuO, SiO2 and H2O with a general formula of CuO.SiO2.2H2O or 2CuO.2SiO2. 3H20. Chukhrov7 has described a sample from the Urals as CU3,5(OH)2 (A1Si3) O10.nH2O and stated that chrysocolla is a montmorillonite-type mineral. On the basis of X-ray analyses, DTA, and infrared spectra of chrysocolla from the Inspiration Mine, Ariz., Sun8 concluded that there was no substantial evidence to classify it as a montmorillonite mineral. Chrysocolla samples from many sources throughout the world were used in this investigation. The following is a brief description of each:

Jan 1, 1963

By J. E. Worthington, W. H. Spence, I. T. Kiff

Gold was discovered at the Haile mine in Lancaster County, South Carolina, in 1827 or 1828, and since that time the mine has been worked intermittently by both open-pit and underground methods until its forced closure in 1942 by World War II. Production figures are incomplete, especially for the early years, but the total gold produced is estimated to have been greater than 200,000 oz. Thus, the Haile mine has been the most productive gold mine in the eastern United States. The upper, residually enriched ores were relatively rich, but the bulk of the production has come from the mining of lower grade ores. General Geology The Haile mine is located in late Precambrian or early Paleozoic rocks of the Carolina slate belt at the edge of the Atlantic Coastal Plain [(Fig. 1)]. The metamorphic grade is lower greenschist facies and the rocks have been folded into a sequence of northeast-trending isoclinal folds. The gold is associated with siliceous, pyritic, and kaolinized felsic pyroclastic and tuffaceous rocks in an interbedded volcanic and volcanoclastic sequence of felsic to mafic tuffaceous rocks and argillaceous sediments [(Fig. 2)]. The ore bodies occur in two northeast trending zones approximately 500 m apart; each zone is 30-70 m wide and 600 m or more in length, with possible extensions to the east beneath the Coastal Plain sediments. Mineralogy. Gold in the Haile mine is always associated with siliceous and/or pyritic ores. The gold occurs in at least three states: As native gold as originally deposited; as residual gold derived from the breakdown of pyrite; and as gold included in pyrite. Major associated minerals in addition to quartz and pyrite are kaolinite, sericite, and iron oxides. Minor molybdenite, arsenopyrite, pyrrhotite, copper sulfides, sphalerite, rutile, and topaz are also present. Petrology. The gold-bearing ore zones vary from highly siliceous rocks to pyritic massive sulfide lenses. This variation is most easily seen today along strike from the Haile pit to the Red Hill pit. Ore grade material still exposed in the wall of the Haile pit consists of a highly siliceous and very thinly bedded rock containing minor pyrite. Along strike, the character of the mineralization changes to pyritic massive sulfide lenses occurring interbedded with siliceous horizons at the Red Hill pit. The siliceous rocks vary from the thinly-bedded material as just described from the Haile pit to silicified fragmental-appearing rocks to totally recrystallized cherty rocks lacking any recognizable primary features. Scattered, apparently at random, throughout the very thinly-bedded and very fine-grained ore face of the Haile pit are seemingly anomalous silica-rich clasts or concretions up to 5 cm in diameter which will be discussed later in this paper. Alteration. One of the most striking features of the Haile deposit is the alteration mineral assemblage which is intimately associated with the siliceous and pyritic ores. This altered material has been intersected in drill core at depths greatly exceeding the modern weathering profile and is, therefore, of hydrothermal origin rather than from supergene processes. This "sericite," actually a fine-grained mixture of sericite, kaolinite, and quartz, can be shown to stratigraphically underlie the gold- quartz-pyrite zone, and is well exposed in the open pit just southeast of the Haile and Bumalo pits. Relict textures indicate that this highly altered material was originally a felsic ash flow. Other similar alteration zones have been found in outcrop and drill core underlying the remaining ore bodies. Thus each of the mineralized zones consists of two parts: A siliceous and/or pyritic gold-bearing ore zone which is stratigraphically underlain by a zone of high alumina minerals, in this case sericite and kaolinite along with variable amounts of quartz. A green chrome mica, presumably fuchsite, is present in trace amounts in the high alumina zone. Genesis An adequate model to explain the origin and distribution of the gold deposits in the Carolina slate belt is presently lacking. Worthington and Kiff1 suggested a volcanogenic origin for certain gold deposits in the North Carolina slate belt from the waning exhalations of felsic volcanic piles. They also pointed out that such an origin has similarities to many epithermal precious metal deposits located in more recent volcanic piles in the western United States. A further key to the understanding of the genesis of the gold mineralization at the Haile mine is the close association of the mineralization in siliceous and sulfidic horizons to the genetically related and stratigraphically underlying high alumina alteration. Such high-alumina alteration is common around felsic volcanic centers in the Carolina slate belt and the mineralogy as seen today consists of some combination of kaolinite, sericite, pyrophyllite, kyanite, andalusite or sillimanite depending on the local prevailing grade of metamorphism. Accompanying the high-alumina alteration are large quantities of pyrite and iron-oxide minerals as well as characteristic minor accessory minerals often including base metal sulfides, fluorine-bearing minerals (topaz, fluorite, apatite), titanium-bearing minerals (ilmenite, rutile),

Jan 1, 1981

The quality of life in many countries of both the developed and the developing world is strongly affected by the products and processes of mining industries. The first Issue in this new series brings together a set of review articles by leading authorities in the field which, taken together, provide a thorough and detailed survey of many of the key topics of current concern relating to the environmental impact of mining. The level of treatment of most topics is at first introductory but evolves through to the advanced level of current research, backed up by extensive citations of relevant primary literature and other sources. Thus the Issue as a whole will be found equally valuable by students of environmental science and those actively engaged in research related to this theme.

Jan 1, 1995

By Theodore M. Gurr, James J. Bartels

Phosphate produced fertilizers provide the phosphorous nutrients required by plant life to sustain significant growth, thus improving the production of food for the world's population. Phosphorous replenishment of soil currently can be obtained efficiently by no other means than by direct application of phosphate fertilizer to the soil. Phosphate products are also utilized in animal feeds, detergent, and various industrial processes. Thirty-three countries are presently mining phosphate rock for the production of fertilizers, and its process byproducts. The major phosphate rock producers are the United States, the former Soviet Union, Morocco, and China [(Table 1)]. Phosphate rock is generally defined as a rock material that contains phosphate minerals which are sufficient for commercial usage. Phosphate minerals are found in sedimentary igneous and metamorphic rocks. Economic resources of phosphates are primarily developed from sedimentary rock sources. The apatite mineral family comprises the majority of phosphate constituents from both sedimentary and igneous rocks. Igneous phosphate rocks are generally composed of fluroapatite whereas sedimentary rocks are generally composed of carbonate fluroapatite, or chlorapatite. Phosphate rock is mined by a multitude of processes, including surface and underground mining. The mined rock requires mechanical and chemical processing to liberate the phosphate for utilization as fertilizer. Approximately 85% of the world's phosphate production uses sulfuric acid, with the remaining processes utilizing nitric and phosphoric acids. Ammonia is also introduced in the manufacture of liquid fertilizer, ammonium phosphate and ammonium polyphosphate. GEOLOGY Mineralogy and Chemical Properties Phosphate most commonly is derived from the mineral apatite, which is chemically described as CA5(F,Cl,OH)(PO4)3. Apatite is also broken up into the composite apatite minerals which are fluroapatite Ca5F(PO4)3, chlorapatite Ca5Cl (PO4)3 and hydroxyl-apatite Ca5(OH)(PO4)3. Carbonate CO3 can substitute for PO, forming carbonate apatite, called francolite. The guano phosphate (bird excrement) mineralogy commonly occurs as brushite CaHP04.2H20, monetite CaHPO4, whitlockite Ca3(PO4), and dahlite Ca10(PO4)6(OH)2. Apatite minerals form from igneous sources where they are developed deep in the earth's crust; and the cooling processes are slow, producing long, hexagonal prismatic to tabular crystals. The termination of the crystal can be basal plans or pyramids. In some instances, the crystals are bipyramids. Faster cooling, or sedimentary derived apatites are more commonly cryptocrystalline. Collophane is a name given to cryptocrystalline apatite found in phosphate rock in fossil form. Apatite minerals are relatively soft and are used to describe the 5 hardness on the Mohs scale. Cleavage is poor and develops along the C(0001). The color of apatite minerals varies from colorless, to violet, and blue, but are predominantly green or brown; luster is vitreous to subresinous. Collophane's physical appearance is often opaline, dense, with colloform structure and sometimes concretionary, nodular or pulverulent. Phosphate Bearing Materials Origins Phosphate deposits of igneous and metamorphic origins have been well defined. Sedimentary origins have been defined, but with a greater degree of uncertainty. Research in the 1980s proved out some of these processes through studies of real time deposition in Chile, Peru, and Australia. Igneous intrusive alkali rock and associated contact metamorphic rocks, provide approximately 20% of the world's phosphate. Fluorine containing apatite minerals are the most common materials containing phosphorous. Fluorapatite occurs in most igneous rocks. Fluorapatite and fluorine hydroxylapatite, together with carbonate varieties of these, are important members of the group. Where an essentially pure chlorapatite, carbonate apatite, and hydroxylapatite are rare and restricted in occurrence, the fluorine containing types occur in most all igneous rocks as early formed accessory mineral, usually in microscopic crystals, and may occur as extremely large bodies as magmatic segregations from alkalic igneous rocks. Apatite is also found crystallized in pegmatitic faces of both acidic and basic types of igneous rocks. More specifically, apatite is associated with magnetite deposits, in hydrothermal veins, especially those formed at relatively high temperatures, and in veins of the Alpine type. Apatite is common in both regionally and contact metamorphosed rocks, especially in the crystalline limestones where it is associated with sphene, zircon, pyroxine amphibole, spinel vesuvianite, phlogopite, talc, chloride schists, and as a contact metamorphic mineral.

Jan 1, 1994

By D. R. Irving

Prior to this time, ample supplies of high grade mineral fillers, such as clay, have been available close to consuming centers. Now depletion of these accessible deposits, coupled with other factors such as increasing demand due to population expansion and standard of living rise, has made development of upgrading techniques attractive to producers. Various investigations being carried out by the U.S. Bureau of Mines are described. Factors making the development of improved methods for upgrading clays attractive to producers include: depletion of accessible deposits of high-grade clays, rising transportation and labor costs, more exacting specifications, and increased demand resulting from an expanding population and a constantly rising standard of living. Industry recognizes the need for upgrading presently unusable materials and has cooperated with the U.S. Bureau of Mines by providing samples from submarginal deposits and by evaluating the products that USBM upgrades. Following are some examples of recent clay beneficiation work by the Bureau. FIRE CLAY BENEFICIATION At the Rolla Metallurgical Center, Rolla, Mo., the Bureau is conducting research to develop technically and economically feasible mineral-dressing methods to remove quartz, pyrite, and other impurities from submarginal fire clays. The research has been spurred by the growing shortage of high-grade bur-ley, flint, and plastic clays in the Missouri fire-clay district resulting from increased consumption and the low rate of discovery of new deposits of adequate quality. There apparently is ample tonnage of submarginal flint and plastic clays to maintain the industry for many years if such material can be upgraded to commercial quality. Samples have been submitted to USBM by several major producers of refractories, including A. P. Green Fire Brick Co.; Harbison-Walker Refractories Co.; Mexico Refractories Div., Kaiser Aluminum and Chemical Corp.; and Wellsville Fire Brick Co. Research on some samples has been completed and still is in progress on others. The Bureau has found that specimens containing quartz or pyrite in grains coarser than the accompanying clay generally can be upgraded either with a gravity table or hydraulic cyclone. The improvement in quality is notable not only in chemical analysis but in an increase in pyrometric cone equivalent (PCE) of one or more cones. As an example, consider the results attained on a sandy flint—a fine-grained mixture of kaolin and halloysite with quartz and minor quantities of iron and manganese oxides. Chemical analysis was: 35.4 pct alumina (A12O3) and 47.8 pct silica (SiO2). The sample contained 9.2 pct free silica as quartz. The PCE was 33. The sample was crushed to -10-mesh, blunged with water, and then stage-ground to -48-mesh. The ground sample was tabled to yield a clay fraction containing 37.6 pct A12O3, and 45.3 pct SiO2 of which 2.4 pct was free silica. The PCE was 34. Recovery of alumina by this process was 73.6 pct. Concentration of the same clay in the hydraulic cyclone was even more effective in respect to quartz removal. The clay fraction analyzed 38.6 pct A12O3, 45.0 pct SiO2 of which 0.5 pct was free silica as quartz, and had a PCE of 34. Recovery of alumina was 71.9 pct. The hydraulic cyclone was also effective in reducing the pyrite content of a plastic clay which likewise was a mixture of kaolin and halloysite, plus some pyrite, quartz, and carbonaceous material. It analyzed 30.6 pct Al2O3, 52.3 pct SiO2, 2.3 pct Fe2O3, and 0.76 pct S. The sample was blunged and screened through 10-mesh to remove some coarse pyrite, then ground to -65-mesh and cycloned to remove most of the remainder. The final product recovered 81.8 pct of the alumina at a grade of 32.3 pct A12O3, 50.9 pct SiO2, 1.4 pct Fe2O3, and 0.1 pct S. The PCE was 32-1/2, compared with a PCE of 31-1/2 for the crude clay. The fine beneficiated clays, of course, must be pelletized and dried or fired to meet commercial acceptance. This operation has already been solved by industry. Little progress has been made on two remaining problems. One is that of fine-grained impurities, not separable by table or cyclone. Flotation is being investigated to solve this. Although fine pyrite is readily rejected, a satisfactory quartz-clay separation has not been attained. The second problem, a stubborn one, is that of alkali. Samples containing as much as 5 pct potas-

Jan 1, 1961

Back at the turn of the century, the Eastern Goldfields region of Western Australia was entering its moment of glory. Development was going ahead at a cracking pace and miles of shaft and drives were being opened up. On the Great Boulder Gold mine alone, records show that there were two kilometres of shaft and 30 kilometres of -driving completed in the first five years of operation.Similar statistics were being achieved by hundreds of other mines on the Golden Mile and in other districts in WA.

Jan 1, 1993

The Annual General Meeting of the Institute was held in Kelvin House, Johannesburg, on Wednesday, August 14th, 1974. Mr P. W. J. van Rensburg (President) was in the Chair. There were present 56 Fellows, 21 Members, 2 Graduates, 5 Associates, 16 Students, and 58 Visitors, making a total of 158. The President declared the Meeting open at 4.08 p.m. OBITUARIES The President: Ladies and gentlemen, before we start the business of the meeting, it is my sad duty to announce the deaths of the following members of the Institute since our last meeting: Dr O. A. E. Jackson, Honorary Life Fellow and Past President; C. Airth, T. L. Blunt, A. E. Frazer, C. L. Lamb, and K. Richardson, Life Fellows; and J. T. Beaumont, Fellow. As you know, there were a number of other deaths during the year, which were reported at previous General Meetings of the Institute. As a mark of respect to the memory of the deceased, and in sympathy with the bereaved, I ask you to rise and observe a few moments' silence. MINUTES The President: Ladies and gentlemen, the next item on your agenda is confirmation of the minutes of the General Meeting and Special General Meeting held on May 22nd, 1974. These will be published in the August issue of the Journal, and, since you have not yet received this, I must ask that they be held over to the next General Meeting. WELCOME The President: It is a very pleasant duty for me to welcome many members of our Institute and our guests, among whom we are particularly pleased to see the President of the Chamber of Mines, Mr Dolf Schumann, who is also Honorary President of this Institute. Mr Schumann, we are extremely pleased to have you with us today. And, we welcome an old friend of ours, Mr Dillon, Minister of Mines in Rhodesia, who has come down for our Annual General Meeting. Mr Dillon, we are very, very pleased to see you here this evening, and we look forward to seeing Mrs Dillon a little later. And we have with us, too, the presidents or representatives of many of our sister and brother associations, institutes, and societies. In particular, we welcome Mr Mike Gericke, President of the South African Council of Professional Engineers, and Professor Midgley, President of A. S. and T. S. We are also pleased to welcome the Presidents of the Mechanical Engineers, Electrical Engineers, Certificated Mechanical and Electrical Engineers, the Civil Engineers, the Joint Council of Scientific Societies, the Mine Ventilation Society, the South African Association of Consulting Engineers, the Association of Mine Managers, the Institute of Foundrymen, the Institute of Welding, the Federation of Societies of Professional Engineers, Mine Surveyors, Production Engineers (London), and the Institute of Production Engineering. We are very glad, too, to have with us a visitor from England, Professor Raynor and Mrs Raynor. Professor Raynor is Professor of Metallurgy at Birmingham University, and a very well-known metallurgist in Britain. We also have with us the Chairman of the Ferro-Alloys Association. We are expecting the Chairman of our Witbank/Middelburg Branch, the Chairman of the Engineers' Liaison Committee, Pretoria, the Director of the Witwatersrand College of Technical Education, and, of course, our old friend, Mr Eric Boden, the Manager of A.S. and T.S. It is a very great pleasure to have with us a number of persons who will receive honorary Life Fellowship at this meeting, and there are some Gold Medal winners and winners of our Student Prizes. We have apologies from a number of people who are away on business, and unfortunately some are ill. But we are extremely pleased to see those of you who are here, and we are also very pleased to see so many ladies. We expect to see many more of them later this evening, at our Cocktail Party. MEMBERSHIP The President: I have pleasure in announcing that, their names having been published in accordance with By-Law 5.2.2., the following have been elected by Council to membership in the following grades Fellows: B. Collins, D. W. Dixon, J. P. Dreyer, A. T. Hudson, and W. W. Pearce. Members: A. T. Fisher and I. F. Nagy. Associate Members : P. D. de Bruyn and H. C. Iverson. Graduates: D. P. O'Shaugnessy and M. F. Sadler. Associates: R. J. Bushell and A. MacDonald. Students : I. J. Barker, P. J. Charter, J. P. de Witt, G. S. Esterhuizen, N. Green, P. M. Jenner, M. J. R. Meyer, A. P. Nicol, W. J. C. Pothas, B. J. Robbetze, N. T. Sutherland, B. A. Statham, C. R. Thomas, N. C. Webb, M. Salamon, R. G. Jurd, and M. McChesney. Transfers to other grades of membership include the following: Member to Fellow: B. W. Holtzhousen. Graduate to Member: T. S. Schultz. Associate to Associate Member: C. L. Jordaan, H. J. L. Tomlinson, J. E. Forbes, G. H. S. Bamford, T. F. Carswell, J. W. Breidenhann, J. R. Garbutt, and L. S. Gibbs. Student to Graduate: C. J. Faueonnier and B. Lund. Student to Associate : G. P. Gooding. We welcome these new members

Jan 10, 1974

By F. B. Foley

IT is with an unusual degree of personal satisfaction that I find myself in a position to pay tribute to the memory of Henry Marion Howe. One could not have spent any length of time in the presence of Dr. Howe without profiting intellectually. I do not hesitate to say that my years of association with him were the most stimulating of all my years of metallurgical study. He always impressed one with his own eager search for knowledge. Never dependent on the written word alone he sought information from anyone whose opinion he valued. His ability to piece together bits of apparently conflicting data from various sources so as to build up a logical hypothesis was unique. A small slight man with the intellect of genius he would have gone to the top in any endeavor he undertook and it was fortunate for metallurgy that its study attracted him as it did. Howe was a modest man. I like to recall an incident which left a lasting impression with me. The lab- oratory in his home, "Green Peace," was in the basement and access was by way of stairs leading down from his secretary's room. In using these stairs my attention was attracted many times to an ordinary cardboard shoe box which reposed on the shelf above the landing. It was crudely labeled on its side in black ink "Vanity Box." My curiosity was aroused to the point that I finally asked his secretary what it was. With some amusement she took the box from its shelf on the stairway, opened it and showed me its contents—numerous letters, from the foremost men of science of every civilized country throughout the world, commending his "Metallography of Steel and Cast Iron." I recall that in reply to one who thought there was not enough of Howe's own researches in his book he wrote, "Primarily I am a writer, secondarily an investigator." Howe wrote to make his readers think. No one ever strove harder than he to be right but above all, whether his viewpoint proved ultimately to be right or wrong, he was always content if by his stand, he provoked a reader to take the next step along the path to greater knowledge. I doubt that he was ever afraid to be wrong for he was always secure in the thought that his effort was guided by a sincere search for the truth. One continually searching for truth is entitled to occasional excursions up the wrong alley. A glance backward to the metallurgical confusion of some thirty to forty years ago, or need one go back so far, provides convincing proof of what a host of companions one may have in a common acceptance of ideas which the future will prove to be wholly untenable. Well over a hundred years have passed since investigators have interested themselves in the effect of increasing the temperature of iron and steel on their mechanical properties. We are told by Charles Walrandl in "Industrial Annals" for June 11, 1822, that bend tests, conducted in a Russian steel works of Prince Demidoff, on steel bars "highly heated" and bent during cooling became brittle when bent at an iris blue color. He concluded, "That when steel is heated to a temperature between 473°F and 662°F the mettle was more brittle between these limits than at a much lower or at a much higher temperature." It was a curious bit of information recognized as true to this day and still not explained satisfactorily. In 1878 Charles Houston in Annales de Mines associated this brittleness with an increase in tensile strength at 572°F. When this relatively low temperature is exceeded it is recognized that steel becomes weaker as temperature is increased up to the melting point, where no strength of practical importance remains. It is easy to believe, in fact it goes without saying, that this weakening as the temperature of a metal is increased is the result of the motion of the atoms making up the metal, a motion which itself is evidence of the temperature increase. However, if we are considering iron or steel we find that this decrease in strength is not a steady one, for, besides the increase in strength just referred to, one comes to a temperature, the critical temperature, where results of tests indicate the metal to be extremely weak and then as temperature increases to become sensibly stronger again. This apparent anomaly was made the subject of the first Howe Memorial Lecture, delivered by Albert Sauveur in 1924. It may be of interest to review these findings of Sauveur. He used two methods of investigation. One involved the twisting of bars. The bars were heated in an

Jan 1, 1951