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Noranda Mines, of Quebec, signed a contract for construction of a $20 million copper refinery at Gaspe, P.Q. The plant is expected to have a 65500-ton daily capacity for both concentrator and smelter. Extensive drilling. around Gaspe has revealed more than 65 million tons of 1 to 2 pct copper in several deposits. Cerro de Pasco Corp. has called a special stockholders meeting for August 19 to obtain permission to engage in the oil and natural. gas business, in addition to its present production of zinc, lead, copper, silver and other metals. St. Joseph Lead Co. recently entered the oil development field. The United States, Canada and Great Britain have agreed to establish a permanent organization to work on unification of engineering standards. General accord has been reached on drafting standards and practices, screw threads, fittings for gas cylinders, and fits and tolerances. Permanent committees will study these fields. Reconstruction Finance Corn approved the largest sum in its history. for a mining enterprise when it loaned $94 million to San Manuel Copper. Corp., of Pinal County, Ariz. The loan will be used to increase production of copper and molybdenum, in what was described as-the biggest copper deposits in the country. Three large gold mining concerns operating in the Philippines told the Philippine Wage Board that they would be forced to close if they had to boost miners' wages 500 to $2 per day. The companies are Mindanao Mother Lodes, Benguet Consolidated, and Balatoc Mining Co.

Jan 1, 1952

By Thomas T. Read

The fact that certain types of ore-deposits have attained their present condition through the action of descending surface waters was, perhaps, first clearly pointed out by Posepny.l The oxidizing effects of such waters were discussed by Pen-rose,2 and many papers dealing with this phase of the subject have subsequently appeared. That secondary enrichment of sulphide ores, however, might be produced by descending surface waters was not clearly understood until after the copper-bearing veins of the Butte district, Mont., had been carefully studied by the geologists of the U. S. Geological Survey, although De Launay3 had suggested that sulphides might be transported from point to point and re-deposited in the zone above the level of ground-water. As a result of the study of the Butte district, two papers by geologists engaged in the work appeared within a short interval. The first by Weed: dealing with the enrichment of veins by later metallic sulphides ; and the second by Emmons; treating of the secondary enrichment of ore-deposits in general. In the latter paper it was pointed out that a typical vein of sulphide ores which has been subjected to the action of descending surface-waters exhibits four zones,—an upper or surface-zone, in which the changes hare been mainly of removal, the products being typically oxides; a second zone of oxide enrichment, in which the less soluble metals brought from above have been precipitated as carbonates or oxides; a third zone of sulphide enrichment,

Jan 1, 1907

By J. M. Clark

(Wilkes-Barre Meeting, June, 1911.) For some years past, those interested in the development of the increasingly important mining industry of Canada, have urged the adoption by the Dominion Parliament of a federal mining-law, which would have the force and stability of statutory enactment. At present, placer-mining in the Yukon Territory, is governed by the Yukon Placer Mining Act. All other mining under federal jurisdiction is governed by 'Orders in Council and Ministerial Regulations. In the earlier stages of development, it is perhaps a matter of necessity that these important matters should be so dealt with; but it is now felt that the time has come when mining-rights in the extensive regions under federal control should be put on a permanent basis, -and that any changes required from time to time should be made only after full and open discussion in Parliament. A short sketch will suffice to indicate how vast and varied the interests affected really are. When the Dominion of Canada was constituted by the Imperial Statute known as the British North America Act of 1867 (which came into force by proclamation on July 1 of that year), it comprised only the present Provinces of Ontario, Quebec, Nova Scotia, and New Brunswick; but provision was made for the inclusion of Newfoundland, Prince Edward Island, British Columbia, Rupert's Land, and the North West Territories. Subsequently Rupert's Land and the North West Territories were acquired, the 'Crown Colonies of British Columbia and * SECRETARY'S NOTE.-Mr. Clark, an eminent Canadian lawyer, and joint author of the treatise on "The Law of Mines in Canada," has been requested by the Do¬minion Government to prepare a Federal mining-law, and presents this paper, by invitation of the Council, in order to obtain, if possible, useful suggestions from members of the Institute.-R. W. R.

Apr 1, 1911

James GayleY, New Pork City (communication to the Secretary*) :—The main thing that is sought after in this matter is that all purcliases shall be made by analysis. This is done already in special lines, as in the manufacture of various grades of steel in which phosphorus, silicon and sulphur are specified within narrow limits, and I quite agree with Mr. Cook that specifications, which are over-rigid in unessential particulars, should be avoided, as they defeat their own purpose because unreasonable requirements permitting no variation are practically not fulfilled, and it is impossible to specify grade

Jan 1, 1905

“IT is decreed by Divine Providence that those who know what they ought to do and then take care to do it properly, for the most part meet ' with good fortune in all. they, undertake; on the other hand, misfortune overtakes the indolent and those who are careless in their work." These are the words of Georgius Agricola. to. those who are engaged in mining, taken from De Re Metallica, Book II, second paragraph. Safety in mining is just that simple, when considered on the basis of the individual. The words imply a .knowledge of what is to be done and how to do it. Armed with this knowledge it is only necessary to proceed with diligence and care to achieve the desired end without personal or financial mishap. Obviously the complication arises in the large company operating numerous mines and the consequent ramifications of company structure embodying management, supervision, engineering, and labor. Agricola stresses later on the importance of supervision and direction by the owners of the mine. We know that this principle is recognized today by the frequency with which the statement is repeated "a safety program must stem from management." People charged with responsibility for safety and management also stress the importance of securing the cooperation of the employees in formulating and carrying . out safe working practices. Safety committees consisting of employees, supervisors, and. representatives of management are recognized as the most practical method of achieving safety consciousness in all levels of mining company organization.

Jan 1, 1952

By R. W. Raymond

I have the pleasure of exhibiting samples of the rock in which the South African diamonds are said to occur, for which I am indebted to Mr. Franz Groeger, of Vienna, formerly an assistant of the Royal Imperial Geological Institution, whose account of the general geology of Southern Africa was contained in a recent number of the proceedings of that Institution. The rock is apparently a sort. of tufa, evidently of volcanic origin. Mr. Groeger assured me that it could be seen in situ, bounded by uplifted stratified rocks; and that diamonds had been mined from it, by means of shafts, some distance below the surface. Groeger calls it " greenstone-tufa," and says of it, in the proceedings of the Geological Institution, " it breaks through the younger members of Group III [lower Trias and Jura], .... and crops out in oval masses, filling fissures.....The occurrence of this tufa is not locally limited, but has been traced and proved already over a large territory." Dr. Hunt remarked that the material looked like the trass of the Rhine region. He thought it a new occurrence for diamonds. He believed diamonds to belong to ancient crystalline rocks, although these materials might be brought up by volcanic agency, and the diamonds remain unaltered. In the volcanic rooks of Auvergne, crystals of sapphire, zircon, and spinel are found; and yet no one supposes that these minerals have been generated by volcanic agency. He had had a conversation with Bertrand de Lorn on this subject, who agreed with him that these minerals, being hard and resistant,

THE Institute of Metals Division of the American Institute of Mining and Metallurgical Engineers appointed a Research Committee in 1925 to de-termine what could be done by the Division to promote research work in the United States on non-ferrous metals. It was recognized that a considerable volume of use-ful research work in this field was being carried on by individual industrial companies as well as by the uni-versities and other research institutions, such as the Bureau of Standards. One need only refer to the recent research literature on non-ferrous metals in the TRANS-ACTIONS of the A.I.M.E., and elsewhere, to be con-vinced of healthful research activity in this field. The appointment of the Committee, however, voiced the impression that what was being done was, however excellent, inadequate for the needs of the industry. It was felt that the Division could usefully devote some of its time and effort in stimulating activity in this field. The deliberations of the Research Committee have not failed to develop wide differences of opinion even on the simple questions: (1) whether the Division can aid in any practical manner in this cause and (2) what the features of such aid might be. However, it was clear that there was only one type of research activity with which it could be very usefully concerned, viz., that on subjects of fundamental interest and general application. It was obvious that research work having special objects and more immediate commercial appli-cation should best be left to the industry itself.

Jan 1, 1927

By L. K. Smith, E. M. de Kock, J. van der Walt

A unique and systematic approach for analysing alternative methods of ventilating and cooling large hot mines is presented. The important factors that have a bearing on ventilation and cooling requirements and practices, such as air flow through the mine, geographical distribution of heat loads, micro ventilation considerations etc., are dealt with. Analysis of these leads to the definitive ventilation and cooling strategies, air and water process design, detail specifications and design of associated plant and equipment.

Jan 1, 1982

By R. L. Dietrich

Magnesium alloy sheet has less ability to accept bending at room temperature than most of the heavier metals. In work designed to improve the bend properties, the preferred orientation of the sheet is of major importance as it is in all studies of the properties of wrought magnesium products. When rolled into sheet, all of the common magnesium alloys form an orientation texture having the basal (002) planes approaching parallel to the surface of the sheet. This texture is only slightly affected by annealing. Magnesium single crystals are highly anisotropic, and, as might be expected, so are magnesium alloy wrought products in which a strong preferred orientation is developed. It is therefore not surprising that bend properties are affected by orientation. Ansel and Betterton1 reported that the orientation of AZ3lXt sheet varies from surface to center and that bend properties are improved by etching away the sharply oriented material at the surface of the sheet to reach the more broadly oriented structure below. This paper covers a study of that orientation, either during the rolling process or by treatment of the finished sheet, in an effort to improve the bend properties and toughness of sheet. Literature The orientation texture of magnesium and magnesium alloy sheet has been studied extensively. Early determinations2 showed that pure magnesium sheet has a preferred orientation in which the basal planes are parallel to the sheet surface within very narrow limits. J. C. hIcDonald3 and J. D. Hanawalt4 reported that sheet containing a small amount of calcium develops a "double" texture, that is, the majority of the basal planes are a few degrees from parallel to the surface and there is a noticeable vacancy at the parallel position. Bakarian5 made careful quantitative pole figures of both pure magnesium sheet and MI alloy SEPTEMBER 1949 sheet which show these features. In all of these studies, however, the orientation was determined by transmission methods in which the resulting pattern is an average through the thickness of the sheet. The tendency of wrought metal to exhibit a different orientation at the surface from that in the center has been reported by many investigators. G. von Vargha and G. Wasserman6 found that with copper, aluminum, iron, and brass the textures of rolled compared to drawn wires were the same at the center but differed markedly at the surface. It was also reported by investigators7 that the orientation of rolled aluminum varies from surface to center. Har-greaves8 found that the surface texture of AM503 (magnesium alloy similar to MI) sheet was different from the center texture. It is reported by Edmunds and Fuller9 that zinc alloy sheet sometimes had a thin layer at the surface with a strong orientation of the basal planes parallel to the surface, which, if present, impaired the bend properties of the sheet. Part1 Surface Orientation ofMag- nesium Alloy Sheet and the Effect on Properties Attempts to correlate the bend properties of magnesium alloy sheet with tension ductility over short gauge lengths proved unsuccessful and the subsequent investigation showed that nonuniformity in orientation is a con- tributing factor as the properties of the surface material have a much more important effect in bending than in tension. A program to study the relationship between surface orientation at the surface and bend properties was then undertaken. First, the effect of etching away the surface of sheet on the bend properties and the orientations at the various depths were studied. Sheet samples of M1, AZ31X, and AZ61X were etched in dilute nitric acid to remove the surface material for various depths to 0.015 in. As may be seen in Table 1, the minimum bend radius improved considerably as the surface layers were etched away but it was necessary to etch the sheet quite deeply, much more so than was found necessary by Edmunds and Fuller9 on zinc sheet. It is also apparent that the amount of etching required is a function of the sheet thickness. In all of this work, radii were measured as R/t, the radius divided by the sheet thickness, in order to eliminate the effect of the reduction in sheet thickness produced by the etching. To determine the orientation texture of the sheet, X ray reflection patterns were taken using copper radiation with the bearn striking the specimen at an angle of 17' to the surface, which is the Bragg angle for the (002) planes of magnesium. Two exposures were made of each specimen, one with the beam perpendicular to the rolling direction and the other with the beam parallel to the rolling direction. The symmetry of the preferred orientation in magnesium sheet is such that these two photographs gave an approximation of the pole figure sufficiently accurate for qualitative work and it was not thought worthwhile to make complete pole figures. These X ray patterns show that the orientation has a much narrower spread at the original surface of the sheet than below the surface. The narrow spread is found in sheet having the majority of the basal planes (002) parallel to the surface, and since this is an unfavorable position for slip, it is

Jan 1, 1950

By George Newton

When Mr. Bailey asked us to present a paper describing our new BOF shop, he requested that we avoid a presentation heavily laden with detail and statistics. Not only have we attempted to do this, but also we have prepared a number of colour slides which, hopefully, will provide you with a graphic conception of the facility. The installation of the BOF facility at the Steel Co. of Canada's Hilton Works was delayed many years because of the remarkable production growth of the oxygen open hearth furnaces in No. 3 shop. However, in mid-1960 it became strongly evident that not only would increased ingot capacity be required, but also that N0.2 shop - with vintage non-oxygen open hearth furnaces - would have to clean its stacks in the near future, or be closed down. A decision to embark on the BOF facility was made in 1967 after an extended period of in-depth planning and assessment of industry trends.

Jan 1, 1972

By T. A. Rickard

The dictionary defines 'jargon' as "barbarous or debased language". This description does not suffice. Quiller-Couch has said, it is "a kind of writing which, from a superficial likeness, commonly passes for prose in these days, and by lazy folk is commonly written for prose, yet actually is not prose at all ". The two main vices of jargon, he says, are "that it uses circumlocution rather than short straight speech", like the Babu who reported his mother's death by saying: "Regret to inform you, the hand that rocked the cradle has kicked the bucket ". Its other chief' vice is that "it habitually chooses vague woolly abstract nouns rather than concrete ones", like the newspaper statement; "He was conveyed to his place of residence in an intoxicated condition", instead of saying, "He was carried home drunk ". Jargon is "an infirmity of speech", it is not journalese, but akin to it. "Like respect- ability in Chicago, jargo4 stalks unchecked in our midst" and renders much technical writing ridiculous. It deals in periphrasis instead of going straight to the point, it loves the abstract rather than the concrete, it dabbles in words of sound rather than of meaning. Avoid it, despise it., if you purpose earnestly to write well. "III literature as in life he makes himself felt who not only calls 4 spade a spade but has the pluck to double spades and re-double." * Jargon is rampant in technical publications. Catalogues and other advertisements are conspicuous offenders, but with these the critic is not concerned, except in so far as such 'write-

Jan 1, 1931

By L. W. Pommier, F. B. Brien

The Rheological properties of pulps are non-Newtonian in character and more than one viscosity parameter is necessary to describe their behavior, therefore, the single term 'apparent viscosity' which has been used in the past may be misleading. The study reported in this paper uses a dimensional analysis based on the Ostwald-de Waele shear stress-rate of shear model for non-Newtonian liquids to develop velocity and resistance equations for falling spheres. An electronic monitoring apparatus was assembled for determining the velocity of metallic bodies as they fall through opaque liquids and suspensions. By means of this apparatus the behavior of the viscosity parameters of the Ostwald-de Waele model and the applicability of the proposed equations were examined for a number of non-Newtonian liquids. The validity of the equations for these liquids was confirmed. Preliminary data collected using solid-liquid suspensions established the validity of the form of the basic equations for these systems. The differential movement of solid particles through solid-liquid pulps and suspensions is very important LO many branches of engineering, such as minerals processing, soil mechanics, ceramic slip processing, oil well drilling-mud technology, materials-handling in pipelines, and many others. There is a dearth of fundamental knowledge on the flow resistance encountered by immersed bodies moving through solid-liquid suspensions. The resistance offered by Newtonian liquids to the movement of free settling spheres is well described for laminar and turbulent conditions by Stokes' and Newton's Laws, respectively. However, problems are encountered when attempts are made to extrapolate these simple relationships into solid liquid suspensions. The rheological properties of pulps are such that they are non-Newtonian in character;'" that is, the applied shearing stress and resulting rate-of-shear are related by non-linear functions, and thus, in the simplest case two viscosity parameters are necessary to describe their rheological properties. For this reason the single term 'apparent viscosity' which has been commonly used to explain the flow resistance of suspensions and non-Newtonian liquids may be misleading. It is realized that a rigorous analysis of the rnechanisms of momentum transport of liquid-solid systems is complex indeed. There are many variables that affect the rheological properties of the systems such as density, size, shape, and surface energy of the suspended solid and density and viscosity of suspending liquid, as well as the solid to liquid ratio. However, it was felt that a useful contribution to the knowledge of the behavior of suspensions could be made by examining the systems in terms of the basic fundamentals of nowNewtonian flow. This has led to the development, by means of dimensional analysis, of velocity and resistance equations, using two viscosity parameters to describe the velocity of penetrating bodies and the flow resistance encountered by these bodies, as they pass through non-Newtonian systems. THEORY In order to examine the effects of the rheological properties of solid-liquid suspensions on the movement of immersed bodies it is appropriate to start with non-Newtonian liquids and develop equations, analogous to those of Stokes and Newton, for laminar and turbulent flow respectively, from which quantitative information may be obtained. Further investigation would then be directed at the complex suspension systems, and the effects of the many variables on the velocity and resistance equations. Liquids are classified on a basis of viscosity which may be defined as the relationship between applied shear stress and resulting rate of shear?-'* Pure single phase liquids composed of small light molecules behave as Newtonian liquids, having a single viscosity parameter since the shearing stress and rate-of-shear are related by a linear function. Bingham plastics are similar but have a yield stress. Of particular importance in our investigation are dilatant (shear thickening) and pseudoplastic (shear thinning) non-Newtonian liquids, with and without yield values.

Jan 1, 1968

By M. R. Geer, H. F. Yancey

THE performance of coal-washing equipment, that is, the effectiveness with which coal and impurity are separated, is a subject of undisputed interest to all concerned with the preparation of coal. Through the years much has been written in both American and European literature on the performance of coal-washing equipment and its interpretation, but until recently no effort has been made to consolidate this wealth of information into a single, comprehensive treatment of the subject. A splendid effort in this direction was made at the First International Conference on Coal Preparation held in Paris in June 1950 in which representatives from virtually every coal-producing country participated. Although the scope of the conference covered the entire field of coal preparation, many of the sixty-odd papers and a great deal of the discussion dealt with the subject of evaluating washery performance. Prominence was given this subject by the Centre d'Etudes et Re-cherches, des Charbonnages de France, which sponsored the conference. This research organization, generally referred to as Cerchar, was formed in 1948 following the nationalization of the French coal industry. Since that date it has conducted an intensive study of coal preparation. Perhaps because of a fresh viewpoint, Cerchar realized immediately that complete information on the performance of French washeries and a thorough understanding of the mechanism of gravity separation were the fundamental prerequisites in a program to improve preparation practice. For this reason Cerchar concentrated on obtaining performance data and on a comprehensive study of methods of evaluating such information. Some idea of the magnitude of this work will be appreciated from the fact that 175 performance tests were made in 44 plants. The work performed by Cerchar emphasized a condition that is recognized by many of those concerned with coal preparation, namely that the lack of uniformity in presenting data on washery performance, the diversity of methods used in evaluating such information, and the frequent confusion of the terms related to performance have been prime factors militating against the progress from art to science. Thus, Cerchar feels that standardization of the methods employed for evaluating washery performance, not only in France but in the entire world, is essential to progress, and the prime objective of the Paris conference was to seek international standardization of the evaluation methods advocated by Cerchar. At the conclusion of the conference the question of standardization was referred to the International Standards Organization. A careful study of the dozen papers on the subject of evaluating washery performance presented at the conference reveals that none of the methods is new; most of them date back over a decade. Nevertheless, the intensive scrutiny of these methods brought about by the conference unquestionably has resulted in a valuable exchange of ideas and a clarification of thought that could scarcely be achieved in any other way. The object of the present report is to make available to the American coal industry the ideas developed at the conference which seem most important from an American viewpoint and to provide a critical analysis of some of the evaluation methods advocated by Cerchar. The various methods of evaluating washery performance are illustrated partly with data that have been published in American literature, and some new data have been obtained as the result of experimental work undertaken since the conference to provide information on certain controversial points. An English translation of the proceedings of the conference, including the discussion as well as the papers, will be available,' and previous to the conference Coal Age2 published a very brief description of some of the principal evaluation methods used by Cerchar. Americans will appreciate as well as do the French the desirability of standardizing both the termi-

Jan 1, 1952

By R. M. Fowler, H. L. Hamner

DURING the last 25 years, there appeared in the literature a number of papers describing equipment and operating techniques for the determination of total oxygen in iron and steel. In the early papers, comparatively little attention was paid to side reactions that occur when iron is saturated with carbon at a high temperature in a high vacuum. As more experience was gained with the new method, the limitations appeared. Metals, with a boiling point lower than iron, distilled out of the crucible, condensed in the cooler part of the furnace, and subsequently reacted with carbon monoxide to form oxides and carbon. Aluminum, manganese, and the alkaline earth metals proved troublesome in this respect. Modifications have been devised to overcome the difficulties due to aluminum and manganese, while the alkaline earth metals are not of too much concern as yet to the steel chemist. The reactions of sulphur have received less attention, although it is generally recognized that some carbon disulphide is probably formed. Liquid air traps have been used in some cases to prevent any carbon disulphide from entering the analytical train. Sulphur was not a particular problem at the Union Carbide and Carbon Research Laboratories until the analysis of the irons of higher than usual sulphur contents became necessary. In order to describe the procedure developed for such irons, it will be necessary to first describe the type of vacuum-fusion equipment employed because the operation of vacuum-fusion equipment is an art to a considerable extent. At the Laboratories, vacuum-fusion equipment has been in daily operation since about 1930. Over the years, the evolution of this apparatus has been governed by the versatility required to analyze a wide variety of materials. Since all types of materials from high purity metals to slags are analyzed and, since seldom more than a few samples of one type are analyzed in succession, the apparatus was designed for accuracy and flexibility rather than for speed. A general view of the equipment is shown in Fig. 1, while Fig. 2 shows the relationship of the various parts. In Fig. 2, A is a vertical double-glazed 24X27/8 in. OD silica tube heated with a 20 kva mercury-arc high frequency generator. The tube is closed with a water-cooled brass head attached with de Khotinsky cement. A turret cap fits on this head and is sealed with a 1/8x3 in. "0" ring. The head contains a sight glass and two 8 in. horizontal glass tubes, for sample storage, cemented in with de Khotinsky cement. B is a four-stage Gaede mercury diffusion pump connected to the water-cooled head with a 11/2 in. copper tube through a flange with an "0" ring. The output of the vacuum pump feeds into an automatic Toepler F pump which compresses the gas sample over mercury in the measuring burettes, G and H. There are bypasses in this line for a McLeod gage C and a Piranni gage D, a manometer E, and for initial pumping out of the system with a Cenco Megavac backing-up pump. The reduction crucible shown in Fig. 3 is machined of Tungar Bulb quality (A.G.K.T.E.-2) graphite. The sample is guided into the crucible with the graphite funnel depicted on this figure. The arrangement of the crucible, radiation screens, etc. in the furnace is as follows: A 1 15/16x61/2 in. Alundum thimble, porosity RA-84, with two 1/8 in. holes near the top and opposite each other which take a pair of special tongs used for lowering it in place, is prepared. A 3/4 in. layer of powdered graphite is placed in this Alundum thimble, and the graphite crucible containing 20 g of ingot iron and 0.5 g of carbon is carefully centered on this bed of graphite powder and graphite powder is packed around it to the top of the graphite cru-

Jan 1, 1953

By C. W. Sherman, John Chipman

IN the mathematical statement of the law of mass action, the activity of each substance consumed or produced in a reaction is used to obtain a numerical constant which is characteristic of the equilibrium of that reaction at the given temperature. The activity in many cases is equal to, or proportional to, the concentration. If this is the case, any units denoting concentrations, such as weight percentage or mol fraction, may be substituted in the equilibrium expression. It is even permissible to use mixed units provided only that each unit is that used in defining the activity of the corresponding substance. The indiscriminate use of concentration units in writing equilibrium constants sometimes leads to very erroneous results. On the other hand, what appear to be contradictory results from similar investigations often might be resolved if the activity is the quantity that is used to determine the equilibrium constant for the reaction in question. De-sulphurization serves as an important illustration. Sulphur in lron and Steel The control of the sulphur content of the finished product is one of the oldest and broadest problems in the metallurgy of iron and steel. In general, this control must be exercised through the action of a slag, and for this reason experimental studies of the distribution of sulphur between slag and metal have assumed considerable importance. Under slags of the type found in the basic open-hearth furnace the ratio (% S)/[% S] does not in general exceed about 8. Under blast-furnace conditions, however, de-sulphurization ratios of 50 to 100 are readily obtained, and under laboratory conditions using similar slags, the ratio may be as high as 400. The fact that blast-furnace metal is much more readily desulphurized than is molten steel rests upon two distinct phenomena. The first of these is connected with the slag reaction. In the open-hearth furnace, the equilibrium in the following reaction places a definite limit on the sulphur content of the slag: S + 0-- = 0 + S- - where the symbols underlined indicate elements dissolved in the liquid metal, while slag constituents are represented as ions. The high oxygen content of the open-hearth bath prevents this reaction from proceeding far enough to effect good desul-phurization. In the blast-furnace process, however, the oxygen activity is limited by the presence of carbon in the metal and in the coke bed and the controlling reaction becomes: S_+O- + C_=S- + CO(gas) [2] The second phenomenon which contributes to the easier desulphurization of blast-furnace metal is the effect of high concentrations of other elements. These elements, notably carbon, silicon, and phosphorus, increase the thermodynamic activity of sulphur several fold. As a result of this increase, the escaping tendency of sulphur from the metal phase is increased and its removal facilitated. Previous Studies It becomes, therefore, a matter of importance to determine the effects of various elements upon the activity of sulphur in the melt. The experimental approach to this problem has been made through the equilibrium between sulphur in the melt and gaseous atmospheres containing hydrogen and hydrogen sulphide. The reaction and its equilibrium constant are written as follows: S + H2(gas) =H2S(gas);K1 = -- [3] Pn2 • as where the symbol a, represents the activity of the sulphur in solution in the metal. The understanding of the chemical behavior of sulphur in steel and pig iron rests on a firm knowledge of the binary system Fe-S. A number of studies of the equilibrium have given closely agreeing results from which the activity and free energy of the dissolved sulphur may be found. The recent paper by Sherman, Elvander, and Chipman1 includes a discussion and quantitative comparison of the results of several of the significant researchesr-" on dilute solutions of sulphur in iron. The results of this study indicate that the relationship between the ratio Ph,s/p+ and the percentage of sulphur in solution is not a linear one. This

Jan 1, 1953

By Jean Bonnemaison

Societe Miniere & Metallurgique de Penarroya Noyelles-Godault works are located in the northern part of France. The complex includes a lead smelter, a zinc smelter, shops for production of manufactured products and all necessary general services. The zinc smelting complex described in this paper was designed in 1959 to replace an old horizontal retort distillation furnace and was first operated in May 1962. It includes: - a sinter plant producing the zinc sinter for the Imperial Smelting furnace : zinc, lead and bulk zinc-lead concentrates are sintered on a Dwight-Lloyd machine with a working area of 80 sq.m. Cadmium sludges are treated by the wet method in a separate plant for recovery of cadmium. Sulphur dioxide contained in gases goes to a gas washing tower and is subsequently made into sulphuric acid in a plant with a capacity of 550 m.t. per day. - a smelting plant where the process developed by Imperial Smelting Processes Ltd. is applied : the blast furnace which was modified in 1967 has an area of 17.5 sq.m. at the tuyeres level and a section of 24 sq.m. at the top of the shaft. It has a theoretical zinc capacity of 100,000 m.t. per annum. Air blast is heated by means of covers up to the theoretical temperature of 950ºC. Zinc produced is either directly cast into slabs for sale as standard 'good ordinary brand' zinc, or sent to a refining plant where the New Jersey process designed to produce 'special high grade' zinc is in application. Mixes of zinc containing various amounts of lead, cadmium or aluminum are prepared to customer specification in a mixing plant.

Jan 1, 1970

By A. E. Bellis, T. W. Hardy

The problem of heat treating high-speed steel becomes more and more important as the design of cutters becomes more and more complicated in increasing the efficiency of mechanical operatioqs. Hundreds of dollars are spent in the design and manufacture of milling cutters of special form for rapid production of duplicate or interchangeable parts, and then, as the heat treatment is faulty on the one hand, or scientifically executed on the other, the tool fails after a few operations, or its efficiency is greatly increased. The practical operation of giving these complicated tools the right temperature necessary to bring out the best cutting qualities, and at the same time bring-the tool out "clean," is a difficult one and calls for no small amount of skill. In order to be on the safe side the average tool hardener uses a temperature much too low to give the best results with the high-speed steel he uses. In the case of cutters which are finished to a given diameter before hardening, it is impossible to grind the tool after hardening, so that it is essential that the surface be protected from oxidizing or de-carbonizing. It is the aim of this paper to describe some experiments on hardening high-speed stee1, in which metallographic means were used to determine the correct hardening tempcratures. The accompanying table and plates show the results of hardening experiments on five different high-speed steels. The analyses for carbon, tungsten, chromium and vanadium of each steel are given in the accom- . panying table. Six specimens from the same bar of each kind of steel

Jan 1, 1917

By Louis Huntoon

THE USE of the aeroplane in engineering work is quite recent. Its general application to all branches of engineering, including mining and metallurgical engineering, is increasing and its possible uses are most promising. Comparatively little has been published on the sub-ject in the mining and metallurgical press, and it is for this reason that the following notes are recorded. In March, 1922, Prof. E. L. Bruce published an article in the Transactions of the Canadian Mining Institute showing the possible applications of the aeroplane to preliminary geological surveys. In October, 1922, Mr. DeShea, representative of the Fairchild Aerial Survey Co., of New York, discussed the subject before the New York Section of the Mining and Metallurgical Society. The writer has been in correspondence with the Laurentide Air Service of Montreal and engineers who have flown. Canada, with its many lakes and rivers-favorable landing places, meets the prerequisite for successful use of the aeroplane in an unexplored and uninhabited or sparsely inhabited country. During the open season hydroplanes are used, and during the, winter season ski runners are attached to the axle in lieu of wheels. With skiis attached it has been found practicable to take off and land on any depth of snow quite readily. Winter flying in northern Canada is quite common. The Laurentide Lumber Co., appreciating the value of the aeroplane, used them for two or three years for timber cruising, and about 1921 turned their equip-ment over to the Laurentide Air Service of Montreal, who operate flying machines. The photographic and engineering work in Canada is done by the Fair-child Aerial Surveys Co. under a contract with the Laurentide Company.

Jan 12, 1923

The early Spanish adventurers found but little gold or silver on the American mainland, and the aborigines in the country that is now the United States were not as submissive as those of the West Indies, so the conquistadores obtained no foothold north of the Caribbean sea. Their later exploration north- ward had Mexico as a base-and wild yarns as a basis. The friar Marcos, a member of Estevanico's unfortunate expedition, brought the story of the Seven Cities of Cibola to Mexico City in 1539. Except as Indian hovels,* they existed only in a disordered imagination, but when Váquez de Coronado's expedition pricked the glittering bubble, there appeared an enticing mirage in the northern desert: the glorious land of Quivira, where even-the common pitchers and bowls were made of solid gold. Coronado proceeded northward and found only enormous herds of buffalo on the plains of Texas. It was a melancholy land. No gold or silver was to be seen among the poor Indians. Coronado reached the country of the Wichitas, in Kansas, before he abandoned his quest and turned home, which he reached, with only a third of his party, hungry and tattered, in 1542. So long as greed stimulates the imagination there will be no lack of tales such as those that repeatedly led the Spaniards to the rainbow's end. In 1860 an expedition was organized in San Francisco by Dr. Darwin French to explore the desert country near Owens lake on the news that the Indians in those parts shot golden bu1lets.t The fact that the savages were known to possess few guns did not discredit the tale, which

Jan 1, 1932

By H. K. Shearer

Oil production in north Louisianat in 1939 was 25,249,640 bbl., a decrease of 11.2 per cent from 1938. The only important increases in production were in the Cotton Valley and Shreveport fields, but Caddo, Homer, Sligo and Zwolle also made slight gains. Greatest decreases were in the Lisbon and Rodessa fields. Xatural gas production of 313,333 million cu. ft. was an increase of 5.6 per cent over 1938. The increase was accounted for in the Monroe field, while all other fields showed only minor variations from the production of the previous year. Well completions in 1939, as compared with 1938, were as follows: The decline in number of completions was due entirely to lack of proved areas for drilling, and would have been greater except for a revival of interest in the old Caddo shallow field. A majority of the wells completed during the year were in various old, shallow fields, so the average depth of drilling was much less than in several preceding years, notwithstanding a few very deep tests. No new fields were discovered, the only wildcat well reported as a producer being a very small oil well in northwestern De Soto Parish, which is of no apparent commercial importance. Deep gas-distillate production in the Cotton Valley formation was opened at Lake Bistineau and Lisbon, and oil at Shongaloo, but all these wells were too small to encourage additional drilling. Extensions and Developments Caddo Field.—More active drilling was donc in the 36-year old Caddo field in 1939 than in any of the newer fields, with completion of 133 oil

Jan 1, 1940