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Jan 1, 1945

By L. W. Casteel, E. A. Jones

MINING the lead deposits of Southeast east Missouri has reached a high stage of technical development dictated by the scattered occurrences of low-grade ore through favorable horizons in the Bonne Terre formation. The rock-breaking, handling, and related practices described here have evolved as the best way of mining these particular deposits. These methods are applied in the production of about 19,000 tons of lead ore per operating day from four mines in Southeast Missouri. Development drilling Drifts 10 ft wide and either 8 or 9 ft high are driven in this district on contract. Miners are guaranteed standard wages plus a bonus on the footage advanced, if earned. Labor, fuse, caps, wire, and dynamite used are charged against the contract. Normally the cycle of operations in drifting is performed by a two-man crew, a motor operator and a shovel operator who first load out the rock broken by the preceding shift. The drift crew then sets up two vertical column and mounts the drills. Cleveland HC-10's are used which have a steel lug integral with the cylinder for connection with the air feed. All drilling in drifts is wet. Air pressure is 85 to 100 lb at the face. From 28 to 32 holes are drilled per swing in a pyramid cut. Cut holes

Jan 1, 1947

By C. A. Heiland

IN the third year of war, geophysical oil exploration broke all records to keep pace with the demand for increased reserves. Geophysical prospecting for strategic and other minerals also grew in scope. The trend of geophysical oil exploration throughout the war is indicated in Fig. 1. This figure resembles the one presented in the last annual review issue of M&M (February 1944, p. 62), corrected for data on-operations in the last months of 1943 and extended into 1944. The average number of geophysical oil prospecting crews in the field in 1944 was 451, whereas the total in 1943 was 340. An upward trend in the use of all geophysical methods is clearly evident throughout the year. Seismic operations were 67 per cent, gravimeter surveys 28 per cent, and other methods 5 per cent of the total. Seismic reflection and refraction crews increased 181/2 per cent over the 1943 average, gravimeter operations increased 73 per cent, and other methods gained 92 per cent. The increase in seismic and gravimeter operations, particularly the latter, is probably due to an increased production of equipment and the organization of new service companies. Miscellaneous methods gained largely through a revival of magnetometer work, and an increase in the use of torsion balances and electrical equipment. In comparison with the prewar average of 1941, it is noteworthy that seismic operations increased 58 per cent, gravimeter operations 88 per cent, and miscellaneous other methods gained as much as 283 per cent. Unfortunately the expansion in the number of geophysical crews does not indicate a proportionate increase in efficiency or in areal coverage, as will be brought out later.

Jan 1, 1945

By Robert Gilman Brown

The original power-plant of the Standard Company has been described* by Mr. T. H. Leggett, late president and manager of the company; but since the presentation of his paper considerable additions have been made, which will be found interesting because of the engineering features involved and of the attainment of a high degree of flexibility with the inflexible, two-wire, alternating system of electrical transmission. Although these additions have been completed during the last year, they constitute, to a large extent, only the carrying out of plans that belonged to the original conception of the installation. The regular operation of the water-power through the winter proved very difficult; there was a considerable length of ditch to be kept open, and, as the stream is small and any freezing night may stop the whole flow of water, there was the .additional trouble of having no reserve to draw upon. The rule for the winter is, that after a night of hard frost water begins to move in the canon before noon on all but the coldest days. To obviate the nuisance of the anchor-ice, and to make available all of the water, a dam of sufficient height to impound several days' run of water has been built across the canon, 3875 feet above the power-house, and provided with pressurepipe well below the surface. In place of the 1571 feet of pipeline from penstock to power-house, there has been substituted a line 3875 feet long to bring water direct from the dam. The dam is of logs, cribbed up in squares of about 12 feet, ballasted with earth and rock and sheathed on the water-face with 3-inch plank.

Jan 1, 1897

By Oswald J. Heinrich

The serious objections to the Leblanc soda process may be enumerated as follows: 1st. The total loss of sulphur employed, equal to about one-third of soda produced. Various processes have been proposed to regain this sulphur, but none have come into practical operation on a large scale. 2d. The great balk of waste products, equal to nearly twice the amount of soda, which forms a serious annoyance about the works. 3d. The complicated series of operations necessary. 4th. The large amount of labor and fuel required. 5th. The prodoction of noxious gases which necessitate extensive condensing arrangements. 6th. The large capital necessary for the . erection and maintenance of the plant, These objections have long been recognized, and many attempts have been made during the last thirty or forty years, to discover and introduce a cheaper and more direct method for the manufacture of this important staple. The reaction between bicarbonate of ammonia and common salt, whereby bicarbonate of soda, insoluble in a solution of chloride of ammonium, is precipitated, has been closely studied for the last twentyfour years, on account of its simplicity and the purity of the product it affords. This ammonia-soda process is now so far developed, that while it is not in position to entirely replace the Leblanc process, yet it can successfully compete with it where the conditions and localities are favorable. The advantages of the ammonia-soda process may be summed up as follows : 1st. It is independent of the essential agent in the Leblanc process, via., sulphuric acid, and hence can be established in those localities where salt is abundant, and yet where sulphuric acid could not be made, or where it could not be transported profitably. 2d. The ammonia-soda process being a " wet" process, the evaporation of salt brines to obtain the solid salt required in the Leblanc process, is rendered unnecessary. 3d. The direct conversion of chloride of sodium into bicarbonate of soda, which can readily be converted into the maketable monocar-

Jan 1, 1879

By Thomas W. Gibson

THE Province of Ontario in recent years has come strongly to the front as a producer of metals, especially nickel, copper, silver, and now gold. Of the last named, the output for 1922 was in the neighborhood of $20,000,000. The law governing the mining industry in a community where such develop-ments are taking place will be of interest, therefore, in other places where mining laws are up for revision The first mining of importance done in this province was for copper on the north shore of Lake Huron, where the Bruce mines were opened in 1846. These deposits of copper sulfides, notwithstanding the remoteness from markets and the cost of transportation, were vigorously worked for 12 or 15 years and also intermittently later, but the active career of the mines came to an end in 1875. From first to last, a little less than 10,000 tons of copper was produced, valued at $3,300,000. All the product was shipped to England as dressed ore, contain-ing up to 13 per cent. of the metal. In. 1866, a rich pocket of gold was found on the Richardson farm near Madoc, Hastings County, but was not followed by further discoveries of a like kind and in time the excitement it caused died away. Rich silver ore was found in 1868 on Silver Islet in Lake Superior, a speck of land not larger than a good-sized ball-room. The assemblage of minerals here was practically the same as that at Cobalt, discovered 35 years later, namely, native silver, cobalt, nickel and arsenic; in addition, there was considerable argentite, which has always been scarce at Cobalt. In all, the silver produced amounted to about $3,500,000. The belief persisted that the deposit was not mined out, and in the summer of 1922, some rich ore was extracted from the roof, perilously near the bottom of Lake Superior.

Jan 2, 1923

By Oswald J. Heinrich

THE serious objections to the Leblanc soda process may be enumerated as follows : 1st. The total loss of sulphur employed, equal to about one-third of soda produced. Various processes have been proposed to regain this sulphur, but none have come into practical operation on a large scale. 2d. The great bulk of waste products, equal to nearly twice the amount of soda, which forms a serious annoyance about the works. 3d. The complicated series of operations necessary. 4th. The large amount of labor and fuel required. 5th. The production of noxious gases which necessitate extensive condensing arrangements. 6th. The large capital necessary for the erection and maintenance of the plant. These objections have long been recognized, and many attempts have been made during the last thirty or forty years, to discover and introduce a cheaper and more direct method for the manufacture of this important staple. The reaction between bicarbonate of ammonia and common salt, whereby bicarbonate of soda, insoluble in a solution of chloride of ammonium, is precipitated, has been closely studied for the last twenty-four years, on account of its simplicity and the purity of the product it affords. This ammonia-soda process is now so far developed, that while it is not .in position to entirely replace the Leblanc process, yet it can successfully compete with it where the conditions and localities are favorable. The advantages of the ammonia-soda process may be summed up as follows : 1st. It is independent of the essential agent in the Leblanc process, viz., sulphuric acid, and hence can be established in those localities where salt is abundant, and yet where sulphuric acid could not be made, or where it could not be transported profitably. 2d. The ammonia-soda process being a " wet" process, the evaporation of salt brines to obtain the solid salt required in the Leblanc process, is rendered unnecessary. 3d. The direct conversion of chloride of sodium into bicarbonate of soda, which can readily be converted into the maketable monocar-

Jan 1, 1879

NORTH AMERICA Number Members Alaska 32 Canada 300 Mexico 165 Newfoundland 3 United States Alabama 43 Arizona 121 Arkansas 9 California 674 Colorado 184 Connecticut 94 Delaware 19 District of Columbia 120 Florida 17 Georgia 5 Idaho 66 Illinois 211 Indiana 56 Iowa 8 Kansas 32 Kentucky 31

Jan 1, 1934

By W. A. Mudge

ONE of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of con-struction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid; of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly tinder others. Furthermore; other properties, physical and mechanical, required in-conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength- alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corro-sion-Resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance

Jan 1, 1935

By H. J. Levinstein, H. J. Guggenheim

RbFeF3 is a transparent ferromagnet with a large faraday rotation which permits the direct observation of magnetic domain structures in bulk crystals. If the position of dislocations within the crystal were known a study of domain wall dislocation interactions would be possible. In this paper an etch pitting solution is described which gives a one-one correspondent between the etch pits and the dislocations intersecting the (100) surfaces of RbFeF3 crystals. In addition, RbFeF3 is shown to have sufficient plasticity so that known arrays of dislocaticms can be put into the crystal. It is concluded that RbFeF, is an ideal material for the investigation of domain wall dislocation interactions. THE influence of lattice defects on the motion of domain walls in ferromagnetic materials has been studied extensively both theoretically and experimentally.4 The experimental data obtained has been qualitative in nature due to the lack either of a quantitative knowledge of the magnetic domain array in the material or of the nature of the dislocation configuration in the material. At room temperature RbFeFJ has the cubic perovskite structure. It is ferromagnetic below 86°K.5,6 It is also transparent and has a large faraday rotation in the magnetic state.7 The domain structure of this material is observable in three dimensions in crystals which are millimeters in thickness.' Since RbFeF3 satisfies the requirements of having an easily visible three-dimensional magnetic domain structure, it was of interest to determine if the dislocation structure of the material could be determined and if the material was sufficiently plastic so that dislocations could be introduced into the as grown crystals. This is a report of the results of that investigation. EXPERIMENTAL PROCEDURE The crystals of RbFeFs used in this experiment were grown by a technique described elsewhere.5 In order to obtain flat strain-free surfaces, the samples were first cut to the crystal orientation desired and the surfaces were polished by employing standard metallographic techniques. The samples were then immersed in a solution of 1 to 3 g of KOH in 100 ml of water. This solution removes the damaged surface layers uniformly leaving a film on the surface of the sample. Etch pits are obtained by immersing the sample in an approximately 50-50 solution of 30 pct peroxide and concentrated acetic acid. The film formed during the KOH treatment turns deep red in color in the etching solution and flakes off the sample. The etching time required depends upon the pit size desired and

Jan 1, 1970

By Alphonse C. Van Besien, Arcy A., L. T. Larson, D&apos Shock, J. W. Peters, Ted H. Eyde, Dermot Ross-Brown, David L. Campbell, W. W. Dudley, John P. Bunch

Over the last several years, unfavorable economic and political pressures on open-pit mining have placed the industry in a generally defensive position. As a consequence, there have been changes in the traditional organizational and production methods to increase operating efficiency. For example, staff groups that were once used almost exclusively for production support are now being organized as mining/environmental specialists. These specialized groups are responsible for obtaining mining permits and insuring compliance with existing permit requirements. Permit issurance and renewal continues to grow as a major budget item in open-pit operations.

Jan 2, 1977

By J. A. Herbst, O. A. Bascur

Fine coal cleaning by froth flotation has become common practice in the US with more than 73 kt/d (80,000 stpd) treated in this way. In spite of this large tonnage, developments in the automated control of coal flotation circuits have lagged significantly behind those for mineral systems. The primary reason is that instruments have not been available for the online measurement of carbon ash content or other critical variables in coal slurries. A second reason is that the influence operating variables have on coal flotation are not completely understood. During the last few years, some of the needed instrumentation has been developed, while an improved knowledge of the flotation process itself has occurred through mathematical modeling. As a result, certain control strategies for coal flotation are beginning to emerge. This paper attempts to evaluate several control strategies using a detailed flotation dynamic simulator, Dynafloat. After construction of a process matrix for the system of interest, promising alternatives for linking manipulated and controlled variables were analyzed. To develop combined grade and recovery control strategies, it was necessary to construct a grade/recovery map with the aid of the simulator to drive the system to known, final, feasible grade/recovery operating conditions. Finally, an advanced strategy that uses an on-line model to identify disturbances and take control actions is proposed.

Jan 1, 1986

By Samuel G. Lasky

What the evidence prevails upon the mind to believe, depends upon the mind as well as upon the evidence. M. L. IN a recent discussion of the mineral resource position of the United States, published in the September 1946 issue of MINING AND METALLURGY, I expressed my conviction that ore deposits of major magnitude remain to be found in this country and that they can be found without undue cost or risk. I stated with equally strong conviction, however, that if the search for such deposits is to be notably successful there must be, among other things, a reorientation of philosophy and mental habits on the part of many who would be connected with the search. I would now like to enlarge upon that statement. For such a purpose, we may consider that the search for concealed deposits involves four steps: (I) the selection of areas for further study; (2) the geologic study of those areas in order to verify their general favorableness and in order to choose specific patches worthy of being tested; (3) the decision whether exploration of the patches chosen should actually be undertaken; and (4) the exploration itself. The first two steps and the last rest upon the judgment and skill of geologists. The third step-the decision whether exploration should be undertaken-rests upon management. In my opinion, the philosophies or principles that have guided these steps in the past are now inadequate. PHILOSOPHY OF APPRAISAL If concealed deposits are to be looked for, how are the places of their possible concealment to be recognized? Every known mineralized area still in the prospect stage has already been repeatedly examined and condemned. As for those deposits concealed under later rocks, there may be not even the clue of a near-by outcrop for engineer or geologist to consider. How then, are we to know where to look? Geologic Probability In the early days of our mining industry, ore deposits were found mainly by "following the ore." Later, as such opportunities decreased, and as geologic concepts became accepted, deposits were found more and more through use of the notion of geologic probability. Many instances can be cited wherein a courageous operator ignored the implications of the unsuccessful efforts of predecessors and, solely by "following the ore," converted a discredited prospect into a good mine. Similar experience doubtless will occur in the future, but "following the ore" will no longer in itself find new deposits in the amount needed. Nor can enough new ore be expected from further use of the notion of geologic probability, for, as mentioned above, our known prospects `have already been ex-

Jan 1, 1947

By B. I. Routh

A STUDY of the effects of temperature on the gel strength of drilling muds is a natural outgrowth of the present era of deep drilling. The control of the gel solids' is now considered important because it affects the wall-building qualities; the suspension of weighting material; the removal and release of sand, cuttings, and gas; and the control of cav-ing formations. With regard to the effect of temperature on gel strengths Herrick2 states: "Temperature variation within ordinary limits does not have much effect on yield points." Lewis, Squires and Thompson3 investi-gated one clay and found no marked change with temperature in either yield point or mobility. Reed4 found that potassium bentonite showed a great increase of gelation with increase in temperature and qualitatively there occurred a marked increase in viscosity upon heating. The apparatus used in these experiments consisted of a Stormer viscosimeter, Marsh funnel viscosimeter, rectangular and cylindrical shearometers, Mudwate hydrometer, and other minor laboratory equip-ment. The various methods of measuring viscosity and gel strength have been extensively described by Evans and Reid.5

Jan 1, 1938

By L. W. Blau

PERHAPS the most important event f or exploration geophysics in 1940 was the publication of three textbooks : "Geophysical Prospecting for Oil," by L. L. Nettleton ; "Exploration Geophysics," by John J. Jakosky; and "Geophysical Exploration," by C. A. Heiland. The literature had grown so bulky, and such a long time had elapsed since the publication of the texts by Ambronn and Eve, that treatises covering exploration geophysics comprehensively in all its branches and giving literature and patent references were sorely needed. This need has been satisfied admirably in these textbooks, and geophysicists owe the authors a debt of gratitude. In 1940, geophysics came of age. A conference on applied nuclear physics was held at Massachusetts Institute of Technology from Oct. 28 to Nov. 2. Several papers on geophysical subjects were presented at this meeting. Geophysical activity has decreased in all parts of the world except perhaps in Canada where, under the stimulus of the war's increased demands, prospecting for oil has increased. However, even there the war has had a seriously adverse effect on prospecting for ores and upon the promotion of new properties, although activity in producing and near-producing mines has been stimulated.

Jan 1, 1941

By F. Peter

Technical progress takes place in two directions: the improvement of methods, affecting the quality of the product; and increase in the economy of operations, affecting its cost. In the iron-industry, practice is pretty well settled, and revolutionary changes of method are, for the present, not to be expected. Hence, in this industry, the principal endeavor is to reduce costs by the use of labor-saving inventions, such as the machines brought into use during the last decade. But it is not alone necessary to reduce the labor-cost; complete economy requires also a saving in raw material. Under this head we may rank the coal employed as metallurgical fuel; and it follows that progress includes the economic use of fuel, so managed as not to injure quality of product. In the present paper it will be shown how, by suitable utilization of the heat from the furnace, a large portion of it may be made available for other purposes. Such utilization of waste-gases is important in all industries which employ furnaces (especially heating-and smelting-furnaces); and in the first rank of these stand the iron-, glass-, and porcelain-manufactures. The following pages are devoted chiefly to the waste-gases of smelting-works, and especially to those reverberatory-furnace gases which are not combustible.' The object of metallurgical furnaces is either to fuse the material charged or to bring it to a high temperature required for further mechanical manipulation. Leaving out of consideration for the present the reverberatory fusion-furnaces, we have to do with the heating-furnaces employed in connection with rolls, hammers, or hydraulic presses. The temperature to which the material must be

Jan 1, 1914

By P. D. Merica, H. Scott, R. G. Waltenberg

The remarkable phenomena exhibited by the aluminum alloy known as duralumin were discovered during the years 1903—1911 by A. Wilm1,2 and have been described by him and by others. 3, 4,5.6 The unusual feature of this alloy is the fact, as was shown by Wilm, that it can be hardened quite appreciably by quenching from tempera-

Jan 1, 1921

Jan 1, 1896

By Theodore B. Comstock

Prior to 1885, the College of Engineering in the State University was under the care of such professors and instructors as were required for efficient work in the Schools of Mechanical Engineering, Civil Engineering and Architecture. The development of the coal and other important mineral resources of the commonwealth led gradually to a considerable demand for instruction in the branches more closely related to mining engineering, and a very creditable effort was made to meet this want by arranging special work in the field and in the laboratory for students of mining and metallurgy. This plan, while it gave much added labor to several already heavily taxed professors, caused such students to become something like undesirable excrescences upon the regular courses. But its partial success gave abundant proof of the real necessity for a complete course in Mining Engineering. The famous Braidwood disaster emphasized anew the importance of thorough training on the part of those to whom the responsible duties of mining must be confided. As is well known, a very excellent beginning was made some years ago by the Legislature in the matters of inspection and regulation by the enactment of a reasonably effective law, which was afterward much improved.* About the date of the last Acts, it was deemed wise to enlarge the facilities at the University arid to furnish adequate training for the increasing number of applicants. Accordingly, in August, 1885, the writer was requested to assume the duties of the professorship, it being the expressed desire of the Board of Trustees and the Regent of the University that a School of Mining Engineering should be founded which might eventually come to rank with the other engineering schools already flourishing here. It is the main object of this paper to state plainly the steps thus

Jan 1, 1887

By R. C. Dalzell, A. E. Wells

In 1866, Thomas Graham1 called attention to the volume of gases, three times the volume of the sample, evolved from a meteoric iron heated in an evacuated porcelain tube. From that time to this the occurrence and significance of gases in metals have been the subject of investigation by many workers, among whom Sieverts,2 Iwasé3 and 0. W. Ellis4 stand preeminent. Sieverts and Iwasé concerned themselves with the solubility of a number of gases in metals in the liquid and solid states. They determined the absorption coefficients of these gases, and in all cases found a sharp change in solubility at the melting point of the metals. Ellis analyzed the gases evolved by solidifying copper and those occluded by the solidified metal. Lobley and Jepson5 endeavored to determine the effects of hydrogen, carbon monoxide and nitrogen on the porosity of copper that was allowed to solidify in the presence of each gas after 30 min. exposure to it in the

Jan 1, 1930