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By C. D. Locker

COMMON salt is mentioned in the most ancient writings as an impor-tant article of diet. It is fairly certain that it was used by men and animals long before the dawn of civilization. Its presence in natural springs has often been the determining factor in colonization; wars have been fought for possession of salt deposits; trade routes have been estab-lished expressly for the purpose of traffic in salt. Naturally this led men into adventures and discoveries that altered history and advanced civilization. In the early days the uses for salt were few and the methods of manu-facture were crude and the purity low when compared to salt of the pres-ent day. Then the salt came largely from springs, shallow wells or the ocean, while today deep wells must be drilled to the natural brines or beds of rock -salt and spacious shafts sunk so that the ancient deposits may be made to yield their supply of stored mineral.

Jan 1, 1936

By Richard P. Rothwell

A REFERENCE to the geological map of Alabama shows the coal- measures of that State to form three distinct fields. The Coosu, or most easterly, contains about one hundred square miles ; the Cahaba, or middle field, which is also the most southern true coal in the United States, contains about 230 square miles ; and the Warrior field, which contains in the State of Alabama some 5000 square miles, is the southern extremity of the great carboniferous deposit, which extends through Pennsylvania, West Virginia, Kentucky, Tennessee, and Georgia. But very little has yet been done towards developing those coal- fields, partly owing to the absence of all commercial manufacturing enterprise in the South under slavery, and partly owing to the want of capital and the disturbed condition of the South since the war. During the past three or four years I have devoted a large part of my time to the examination of the coal and iron ores of this range,

Jan 1, 1874

By Ellis Clark

DURING the winter of 1877-78 the Glendon Iron Company, by the advice of the superintendent, Mr. Frank Firmstone, decided to make the experiment of exploding a heavy blast of gunpowder in their limestone quarry at Cedar Hill, Palmer Township, Northampton County, Pennsylvania. The amount of limestone used in the five furnaces of the company is about 60,000 tons per annum, and it was thought that with successful results; this entire amount or more would be thrown down at a single operation, disintegrating the mass to a greater or less extent, and obviating the necessity of blasting and boring the rock from the face of the cliff, both of which operations are slow, and therefore, costly. The rock at the quarry is Auroral limestone, or No. 2 of the old Survey. No fossils have ever been found in the quarry, nor in the immediate vicinity. The nature of the rock varies considerably in

Jan 1, 1879

By Ellis Clark

During the winter of 1877-78 the Glendon Iron Company, by the advice of the superintendent, Mr. Frank Firmstone, decided to make the experiment of exploding a heavy blast of gunpowder in their limestone quarry at Cedar Hill, Palmer Township, Northampton County, Pennsylvania. The amount of limestone used in the five furnaces of the company is about 60,000 tons per annum, and it was thought that with successful results? this entire amount or more would be thrown down at a single operation, disintegrating the mass to a greater or less extent, and obviating the necessity of blasting and boring the rock from the face of the cliff, both of which operations are slow, and therefore, costly. The rock at the quarry is Auroral limestoue, or No. 2 of the old Survey. No fossils have ever been found in the quarry, nor in the immediate vicinity. The nature of the rock varies considerably in

Jan 1, 1879

By W. S. Ayres

The protractor here to be described embodies several important improvements that have been suggested by the use of other protractors and by observing the errors occurring in practice with them. It is more particularly an improvement

Jan 1, 1896

By A. Taylor, S. Leber

WHEN studies of deformation texture, lattice stress, and crystal orientation are made, it is frequently required to know the interplanar angles and subsequently to embody the results of the investigation in a stereographic projection. Tables of

Jan 1, 1955

By W. L. McMorris, A. H. Brisse

IN the last several years the coal industry has intensified its effort to solve the growing problem of cleaning and recovering fine mesh coals. On one hand there has been increasing civic pressure for cleaner streams, and on the other hand there has been increasing production of fine mesh coal, resulting directly from adoption of the modern mining methods so essential to the economy of the coal mining industry. Cleaning fine coal with the same precision possible with coarser coals is a difficult task, and for coals finer than 200 mesh it has been impractical. Furthermore, the inclusion of -200 mesh material in the final product markedly increases costs of dewatering and thermal drying, which are necessary steps if coal is to meet market requirements. Consequently these extreme fines have generally been wasted. As a result, problems have been created in many districts because there has not been enough area for adequate settling basins.

Jan 2, 1958

By H. M. St. John

LIKE every present-day manufacturer, the brass foundryman is faced with the necessity of reducing the cost of his finished product without impairing its appearance or quality. He must use every economy that the progress of art and science puts at his disposal and should also be alert to profit by any peculiarity in his own situation or the nature of his product that may give him an exceptional advantage. Much can be accomplished by the adoption of labor-saving equipment and improved methods of melting, molding and handling. Control of pouring temperature, study of defective castings and their causes, laboratory control of molding sand and core mixtures, the use of less expensive alloys, all contribute to the desired end. Assuming that the composition of the alloy is already as inexpensive as the character of the casting will permit, still further savings can be made by the intelligent purchase and utilization of the metals needed to produce the desired analysis.

Jan 1, 1929

By R. Schuhmann, A. M. Gaudin, J. Dasher

Occurrrences of South African uranium have been known qualitatively for over twenty years, but no account was taken of them because of their low grade. In 1945, known uranium deposits were few, but their grades were 20 to 100 times higher than South African ores. Viewed in this light, the exploitation of South Africa's uranium is revolutionary indeed. Development of various analytical procedures capable of dealing with the needs of the project accounted for one-half of the cost and included: a) simple and automatic radiometric analytical procedures, b) sampling procedures appropriate to prevent sample contamination, c) procedures for sample and record-storing to accommodate many thousands of analyses per month, d) chemical methods giving high accuracy analyses for high grade samples not at radioactive equilibrium, and e) development of rapid procedures having moderate accuracy for low grade samples i.e., mill tailings and barren liquors. This task is continuing today with major improvements coming from time to time.

Aug 1, 1956

By T. M. Olson, B. G. Lewis

The adsorption of selenite on bentonite, kaolinite, and an iron--coated illite was studied to determine the importance of several soil variables on selenite removal from uranium mill tailings pond seepage. Adsorption capacities of the clays of selenite varied by orders of magnitude and decreased in the following order: illite > kaolinite > bentonite. Maximum adsorption of selenite on the clays was observed between pH 2.5 and the clay's zero-point-of-charge. Substantially less selenite was adsorbed on these clays in actual mill tailings solutions than in model systems. Virtually all selenite was removed from the tailings at pH 7. The principal removal mechanism at this pH is suggested to be the adsorption of selenite on freshly precipitated metal hydroxides. It is concluded that selenite can be removed from tailings seepage in soil or in clay liners in the presence of kaolinitic clays and iron oxides. Selenite would also tend to be removed from tailings seepage in calcareous strata.

Jan 1, 1984

By Donald W. Gentry

Many firms in the minerals industry are facing enormous capital-equipment requirements for existing operations, planned expansion programs, pollution control systems, etc. Yet, because of existing economic conditions, mining companies find it increasingly difficult to obtain reasonable financing for the acquisition of large, high-cost capital equipment. One way of obtaining the use of mining and other major pieces of high-cost capital equipment is through leasing. The popularity of this approach is evidenced by the growing number of leasing companies, equipment manufacturers, and financial institutions now offering this service to their customers. Indeed, leasing has become a billion-dollar industry, and many commercial banks have developed sizeable portfolios in this area. "Should we buy or lease?" This question eventually comes up whenever a mining company needs additional major capital assets. Unfortunately, many buy-or-lease decisions are made on an emotional basis-rather than on a proper financial evaluation that would yield the…

Jan 9, 1975

Alexander N. Winchell, Butte, Mont. (communication to the Secretary): Mr. Spurr calls attention to the fact that an ore-deposit may be due to a succession of concentrations at different geological epochs. He cites an example of such a condition on Napoleon creek, a branch of Forty-Mile creek, Alaska. It will perhaps be of interest to call attention to another example of the same general character, not so remotely situated. The example referred to is located on Pole creek, a tributary of Cherry creek, in the extreme northeastern part of Madison county, Montana. An excellent geological map of this region is to be found in the Three Forks folio (No. 24) of the United States Geological Survey. According to this map, Pole creek, in its upper course, occupies the contact between the " Flathead " formation, which Peale correlates with the Middle and Lower Cambrian, and an area of gneisses and schists supposed

Jan 1, 1903

By J. C. Donnell, O&apos

Sinking an inclined ventilation shaft at the Never Sweat mine of The Anaconda Co. has required a unique underground hoisting arrangement because the shaft changes direction from vertical to 71.5º. Access to the project is made through the High Ore shaft to the 2800-ft level, then by crosscut to the bottom of the vertical Never Sweat shaft. The 71.5º incline shaft starts at this point, which makes an unusual operation as the 60-cu ft sinking skip coming up the incline changes into a vertical position above the 2800-ft level before going into the dump scrolls. This requires both rollers and guide shoes on the skip. Coming up the incline to the collar of the shaft the loaded skip enters into a guard before reaching the vertical section. The tendency of the surface- mounted Never Sweat hoist is to lift the front wheels of the skip off the track, so the guard keeps the skip on the rails during the transition.

Jan 11, 1965

By Will Mitchell

There are in this country some 20 or 30 societies for engineers and engineering scientists. Most of these organizations are autonomous, and there is little or no cooperation among them. Many do not touch the lives of our Institute members. However, during the course of the years several societies closely associated with the AIME have banded together to handle specific situations where cooperation was necessary. It is believed by many engineers that the functions of these cooperative societies should be analyzed and a plan set up to unify the engineering profession into an organization similar to the American Medical Association and the American Bar Association. The preliminary study of the AIME Committee for Inter-Engineering Society Cooperation has indicated that the following organizations bear upon the professional lives of our members. Some of these are federated groups, such as EJC and ECPD; others are individual-member participation groups, such as the Founder Societies and NSPE.

Jan 10, 1960

By Joseph Cervik

INTRODUCTION Common methods of controlling gob gas in U.S. mines are by means of ventilation of gob areas and gas drainage through surface boreholes. Costs of drilling surface gob holes increase as deeper coal- beds are mined. Where gob holes cannot be drilled because of topography, ventilation is the only means of control. Even then, sufficient air may not be available to dilute methane in the bleeder entries to acceptable levels. Thus, new methods of gob gas control need to be developed that are independent of surface topography, and of the mine ventilation system, and less costly than present systems. Except for slight variations in procedures and equipment, Great Britain, West Germany, France, Belguim, Poland, and Czechoslovakia use a common methane control method that is different from the system generally used in the United States. This Bureau of Mines paper reviews European mining methods, mining conditions, and methane control technology and discusses their applicability to U.S. mines.

Jan 1, 1981

By George F. Kunz, Henry S. Washington

The recently discovered occurrence of diamonds near Mur-freesboro, Pike county, Ark., was brought to our attention by Mr. Samuel W. Reyburn (Trustee for Messrs. C. S. Stifft, A. D. Cohn, August Zinsser, Jr., and himself, owners of the property), through whose courtesy we investigated the locality of the deposit. Prospecting with the diamond-drill is now in active progress; but mining operations on a large scale have not yet been ordered. Geology.—The geology as well as the petrography of this interesting locality has been well described by Messrs. J. C. Branner and R. N. Brackett,' but they did not class it as dia-mondiferous, although Branner suggested that it might be. Briefly summarized, the igneous rock in which the diamonds are found is a vitreous peridotite, forming a stock or volcanic neck, which has broken up through the Carboniferous and Cretaceous quartzites and sandstones. After an extensive period of erosion, during which an unknown portion of the neck and pre-

Jan 1, 1909

By Charles H. Mitchell

British Columbia is enjoying a period of sustained high-level activity in all aspects and sectors of its mining industry. The total value of mineral production for 1962 was in excess of $229 million. This was the greatest total value attained for any year to date, exceeding the previous record year of 1956 by more than $40 million. It appears reasonable to expect that value of production for 1963, stimulated by increased production attained during the year, and by improved metal prices for some of the major products, will be substantially in excess of that recorded for 1962. Elsewhere in this issue appears a detailed report of prospecting and exploration activity in the Province. For the purposes of this review it is sufficient to state that the level of prospecting and exploration activity during the past several years has been greater than at any previous time and that there does not appear to be any slackening in activity or interest.

Jan 12, 1963

By R. J. Lutton

Basic features occurring on tensile fracture surfaces in rock are hackle marks, steps, and rib marks. Rib marks define the leading edge of the fracture and indicate that it was free of irregularities. In turn, fractures characterized by these features are believed to have propagated elastically and to be truly brittle. On the other hand, most fractures in rock exhibit hackle marks and steps in a plumose arrangement, indicating a ductile fracture process. Accordingly, the edge of the fracture apparently advances by extending en echelon fingers, each of which is in turn a small plumose fracture. Plastic-like deformation takes place in this zone prior to complete rupture. Some of the propagation is directed sideways and some shearing also occurs in this direction. Such lateral movement contributes little to forward propagation and may make this process particularly sensitive to load rate and duration and help account for greater fracture strengths of materials under dynamic loads.

Jan 1, 1971

By G. Rinelli, A. M. Marabini

Flotation of rutile with N-benzoyl-N-phenyl-hydroxyhmine (N-BPHA) has been investkated. Initially, floatability tests were performed in a Hallimond tube. The results indicated that rutile was floatable at pH 2-4 with N-BPHA concentration between 2 x 10-3 mol/L and 2 x 10-2 mol/L. Selectivity against hematite was recognized when operating at pH values below 2. Following the hypothesis of the formation of a surface chelate between N-BPHA and titanium ion, this compound was precipitated from a solution of Ti (SO4)2 to which N-BPHA was added. I. R. spectrometry of the rutile before and after treatment with N-BPHA solution confirmed the presence of this compound on the rutile surface. Adsorption isotherm and kinetics were determined by analyzing N-BPHA in solution with an U. V. technique. A hypothesis on the way N-BPHA is adsorbed on rutile is presented.

Jan 1, 1984

By T. H. Janes

NATURAL abrasives of some type are found in all countries of the world. In order of their hardness the principal natural abrasives are diamond, corundum, emery, and garnet, which are termed high grade, and the various forms of silica, including pumice, pumicite, ground feldspar, china clay and, most important, sandstone. The properties qualifying materials for use as abrasives are hardness, toughness, grain shape and size, character of fracture, and purity or uniformity. For manufacture of bonded grain abrasives such as grinding wheels, the stability of the abrasive and its bonding characteristics are also important. No single property is paramount for all uses. Extreme hardness and toughness are needed for some applications, as in diamonds for drill bits, while for other purposes the capacity of the abrasive to break down slowly under use and to develop fresh cutting edges is of greatest importance, as with garnet for sandpaper. In dentifrices, soaps, and metal polishes, of course, hardness and toughness are objectionable.

Jan 10, 1954