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By S. F. Shaw

Tars paper is a review of the principal details of cyanide practice in several of the modern plants in America, mainly during the year 1908. Two of the mills, the Goldfield Consolidated and the Vets, Colorado, are not yet prepared to give data, the former having started about Jan. 1, 1909, and the latter not yet being completed. These two mills embody most of the latest methods and are therefore described as far as possible. I. CRUSHING. The principal methods of crushing ores for treatment by the cyanide process are with gyratory and jaw-crushers, stamps, Bryan and Huntington mills, and tube-mills. The first stage is usually done by gyratory or jaw-crushers, in a few cases sup-\

Jul 1, 1909

By L. A. Cranson

WHEN I came out of Stanford University in 1922, the out-look for men trained in geology, petroleum engineering, and mining was indeed dismal; in fact, so much so that most of us looked upon our future in those fields as pretty hopeless. Neither our professors nor those men in industry with whom we came in contact gave us any enthusiastic encouragement as to the future of ourselves or the fields we had chosen for our labors. I believe that the attitude of pessimism which saturates everyone about graduation time is lament able and short-sighted, and may often start a young man on his way with an attitude of defeatism. Instead, he should be starting out knowing that he can expect hard work and keen competition, but that the fields of his labours are expanding at an accelerated rate, and that strong, energetic efforts will as always accomplish highly satisfactory results.

Jan 1, 1941

By Northcutt Ely, Charles F. Wheatley

This chapter deals with the systems of laws by which governments regulate the exploration for and production of the minerals within their jurisdictions. It is a summary, restricted by necessary space limitations, of material assembled by the author for a forthcoming publication of the United States Bureau of Mines, "Summary of Mining and Petroleum Laws of the World." (Information Circular, 1959.) The present study is organized in three parts, dealing with (1) the historical background of these legal systems, (2) laws of the United States, and (3) laws of other countries of the world. The reader's attention is invited to the acknowledgments at the end of the chapter, which inadequately express the appreciation due those who have assisted in the collection of this material. Part I. Historical Development of Major Western Systems of Land Tenancy with Respect to the Ownership and Control of Minerals The use of metals in primitive societies was largely confined to the manufacture of weapons for self-preservation. The ruler's control over copper, then brass, then iron, was essential to maintenance of his own ascendancy at home and his group's position against neighbors who had access to similar metals. Ancient societies were thus characterized by the ruling group's ownership of minerals and metals. The Egyptian civilization, which emerged in the fourth millenium B.C. upon the agricultural subjugation of the lower valley of the Nile, was responsible for extensive development of the upper valley as a source of mineral wealth. The production of gold during the height of that civilization has been estimated at $30,000,000 per year, thus equaling the early placers of California and Australia. The mines of Egypt were the property of the Pharaohs and were controlled at their direction. Greek mining developed a different scheme of land tenancy which more closely resembled modem concepts. Development of mineral resources was

Jan 1, 1959

By AIME AIME

FOR the mineral industry, as for many others, the year 1944 brought to fruition the seeds planted in previous war years. Accomplishment in attaining ends in the production of minerals has given more time for the consideration of postwar problems, such as plans for resuming production for civilian uses and measures to prevent possible mass unemployment. The hectic atmosphere in production circles lessened during the latter half of 1943, conditions becoming static during 1944 as peak production rates were reached. Withdrawal of deferment of young men from the mining districts by Selective Service connotes that man power at the battlefronts became more important than the persistence of pressure for metal production. This is in contrast to the return of soldiers in 1943 to augment the labor ranks in the mining districts. The year ended in the midst of changing needs. Over-all metal production in the United States in 1944 will record a lessening, compared with the previous year owing to labor shortages which affected both development work and ore output.

Jan 1, 1945

By Walter W. Bradley

FOR a number of years up to the economic setback of the 1929-1931 period, the greatest proportional advances in the mineral industries in California were made among the substances in the nonmetallic groupings, particularly among the so-called industrial minerals and the salines. During the past year or two, although these have not regained the stride that marked their progress in the preceding decade, we can still record, -some new developments. California produces annually between 55 and' 60 different minerals on a commercial scale. Of these, some 40 to 45 comprise the "structural," "industrial," and "salines" materials as grouped in the reports of the State's Division of Mines. Barite-The barite deposits of California were described in Report

Jan 1, 1935

By Lawrence K. Nordell

This paper reviews practices used In the selection and sizing of belt conveyors and stacker systems commonly used in crushing and grinding plant facilities. Historical and modern methods of sizing this equipment are presented. The new methods Include: 1) probability theory applications for establishing component reliability, 2) "Monte Carlo" simulation techniques used in evaluating alternative system designs and in establishing service factors and corresponding availability Indices of each system, 3) quantifying the system and component operating characteristics using computer assisted modeling tools simulating rigid body and elasto-mechanic behavior for starting and stopping large and/or complex belt conveyors.

Jan 1, 1982

By J. B. STEWART

T HE position of each hole of any series of holes was carefully located by the surveyor, plotted in plan and elevation, and numbers assigned to them. The second series was staggered halfway between the first and so on for each succeeding series. Two and a, half to three months was frequently required to grout a series of holes calculated to insure safety for sinking a distance of 10 meters or say 33 ft. Naturally the initial operation called for drilling and grouting two series of holes but thereafter each sinking campaign required only one series of holes as shown in Fig. 8. The pump handling about 75 gal. per minute corresponds to 46 tons of grout or 6 tons cement delivered as a fair over-all average for the 24 hours. Thus 600 to 800 tons of cement was used for a single section of 33 ft. depth of shaft. One campaign used nearly 1100 tons of cement. Some holes were effectually sealed with as low as 30 tons, while many required 60, and some 80 to 90 tons.

Jan 1, 1926

By T. Lane Carter

(Canal Zone Meeting , October , 1910.) INTRODUCTION. IT is a curious fact that while in our Transactions there are papers dealing with mining-districts in all parts of the world, in Europe, Asia, Africa, and Australia, there is not one which describes the mining possibilities of Nicaragua; our near neighbor. To be most interested in distant objects, like the moon, .and to neglect what lies at our feet, appears to be a trait of human nature. The neglect of Nicaragua is not confined to the American Institute of Mining Engineers. In no other transactions am I :able to find papers dealing with mining in Nicaragua, some parts of which are as much in need of discovery and research as the North Pole.. I hope this paper will be the precursor of many others to be printed in our Transactions, dealing not only with the mining possibilities of Nicaragua, but with the whole of Central America, where there are vast areas awaiting skill and capital for their development. Much of this capital and skill should come from the United States in the future, although it is probable that European capitalists, when they appreciate fully the possibilities, will investigate more and more the mining-resources of Nicaragua and other Central American republics. Fig. 1 is a sketch-map of Nicaragua showing the principal mining-districts. II. HISTORY. Mining in Nicaragua did not begin yesterday. It was commenced by civilized man when the Spanish conquerors penetrated into the interior and forced the natives to procure the precious metal for them. It is strange that the Spaniards did not find more gold, and work on a scale as extensive as in Colombia and other parts of South America. Probably in Nicaragua the Indians covered up most of the rich prospects

Dec 1, 1910

By J. D. Price, W. M. Bertholf

In preparing a paper on coal washing in Colorado and New Mexico, it is difficult to refrain from entering into a discussion of the historical aspects of this subject, for the story of coal washing in these states goes back well into the last century. This phase of the subject could well make a complete paper in itself, and of necessity this present discussion must be limited to current operations. Therefore, we are taking into consideration only those washing plants which have operated for some period during the years of 1947 and 1948.

Jan 1, 1949

By Stanley W. Ivosevic

The South-Central Osa Peninsula produced around 30,000 kg (100,000 troy oz) of gold since prehistoric times. Gold freed by erosion from quartz lodes in the Mesozoic Nicoya ophiolite complex was reconcentrated through three generations of Quaternary sedimentary deposits. Resultant gold placers grade upward from 1 g/m3 (0.03 troy oz/m3) and are of moderate size.

Jan 1, 1980

By Fred R. Ingram

FOR the purpose of this discussion, let us consider that the Rocky Mountain region covers the area in the seven Mountain States, Idaho, Montana, Wyoming, Utah, Colorado, New Mexico, and Arizona, and before we discuss the needs of these states, let us define Industrial Hygiene. Industrial Hygiene is that branch of preventive medicine concerned with the protection of health, improvement of efficiency, and prolongation of life of the industrial worker; in short, adult health conservation. It includes in its broad meaning not only the prevention of occupational diseases, such as silicosis, lead poisoning, cadmium poisoning, and many others, but such relative problems as overcrowding, fatigue, and personal and mental hygiene; exposure to abnormal temperatures, pressures, and humidities; ventilation, heating, and lighting. It is a science which requires the combined activity of medical personnel (doctors and nurses), engineers, and chemists to evaluate the exposures and determine the means of eliminating the hazard. The engineer surveys the workplace, takes air samples at the breathing level of the workman, and analyzes the work exposure. The chemist determines in his laboratory the exact amount of toxic material collected in the sample, which represents the exposure of the workman. The doctor must diagnose the occupational disease, recognize its cause, and evaluate the disability. Together, all three must correlate the data obtained and devise efficient methods, medical or engineering or process changes, for controlling or minimizing the dangerous condition and for studying the effectiveness of these measures. The plant doctor, in addition, must aid in the readjustment of the incapacitated worker and provide facilities for prevention. Industrial hygiene, however, is of no avail without the understanding co-operation of management.

Jan 1, 1945

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 C. D. Woodward

THE subject of electric signals for the despatching off mining cages through shafts has received cousiderable attention recently from various mining companies. The Anaconda Copper Mining Co. has found it necessary to develop a system that is reliable, safe and simple in operation, and easy to repair. The movement of all mine cages or skips is under the direction of a station tender, who rides on the cages when men or supplies are being lowered or raised. When ore is hoisted, he is stationed at a skip pocket for loading and despatching the skips. For the station tender's use, two signal systems are installed in each hoisting compartment, and he is the only employee authorized to use them. One system is known as the "AC" or Station bells, as it is operated from the 110-volt, 60-cycle, power service; the other system, called the "DC" or shafts bells, takes its energy from closed-circuit primary batteries. As a supplement to the two main signals, a buzzer system is installed. The general arrangement is similar to "the main signal, except that there is a mine buzzer at each station. When a signal switch connected into the buzzer system is pulled down, all buzzers are operated, thus notifying the station tender that he is wanted at some particular level. Placed on the station posts, and within easy reach of the men on the cages, are the signal pull switches for the main signals. The station, or "AC," pull switches are furnished with a short rope as shown in Fig. 1, while the shaft, or "DC," pull switches are equipped with ropes that extend down the shaft past the next station. To avoid all confusion in the use of the three signal systems, a standard arrangement has been adopted in all mines for the location of the pull switches. Fig. 2 illustrates the position of the pull switch at the various mine stations for the main signal systems, but it does not show the buzzer pull switch; this is fixed to the roof timbers about 25 ft. back from the shaft. If the skip pockets are a considerable distance below the station, a pull switch for each main shaft compartment is connected to the "AC" system and placed at this point. However, if the distance is short, a light cord is attached to the station pull switches and dropped down to the skip pocket.

Jan 2, 1922

By Westwater, J. S.

The Mather mine of The Negaunee Mine Co. embraces nearly all of Sections 1 and 2, T47N, R27W. within the limits of the cities of Negaunee and Ishpeming on the Marquette iron range of Michigan's Upper Peninsula. Operations of the Negaunee Mine Co., the stock of which is jointly owned by Bethlehem Steel Co. and The Cleveland-Cliffs Iron Co., are under the direction of the latter company. The opening of the Mather mine was described by C. W. A1len. Mather "A" shaft was completed to an initial depth of 2352 ft in early 1943. The shaft capacity of over one million tons yearly is in prospect of being realized by orderly development and mining, and sinking of the second or "B" shaft then started in accordance with previous planning. Mather " B, " also a vertical shaft, was designed as a twin to Mather "A" shaft and the sinking technique developed at Mather "A" was utilized in "B" shaft operation.

Jan 1, 1949

By W. L. Honnold

AS BOTH South Africa and diamond mining are unfamiliar subjects it seems best that on such an occasion as this I should endeavor to reflect the atmosphere of the place and to picture the mines from an industrial rather than from a technical standpoint and, because of long absence, my remarks must necessarily be sketchy and in some particulars not up to date. The preferable route to South Africa is via England, direct steamers from America being inferior as to service and effecting no saving of time. The newer boats are of about 20,000 tons capacity and very comfortable. Seventeen days are required for the voyage and only one stop is made-that at the island of Madiera, three days out. Between Southampton, the port of departure, and Madiera the weather may be warm or cold and the

Jan 1, 1925

By W. R. Ingalls

THE propaganda in favor of the adoption of the metric system of weights and measures in the United States is founded upon the idea of compulsory adoption. There can be no argument about this, for the metric system has been legal, by Act of Congress, in the United States since 1866. Nobody ought to oppose an educational movement, and if pro-metric activities were confined to that there might be no reason to gainsay them. I do not propose to enter into any discussion of 'the relative merits of the metric and the English systems of weights and measures. The simple case is that the metric system not having made much headway in the United States after more than 50 years of legality, 'it is now aimed to force it upon the people by legislative compulsion. The main arguments in favor of such compulsory adoption are that it would- simplify the education of our children and would promote our foreign trade, for the reason that more countries of the world, with which we do business, use the metric system than the English system. I am going to disregard,' in this contribution, the first of these arguments, for it is largely conjectural." Not so with the other, which is specific, and being so its speciousness can be, proved. It is true that the metric system is used by more countries of the world than the, English system. It is commonly stated that of the Indo-European nations only the United States, Great Britain, and her colonies, and Russia have failed to adopt it. However, if with "colonies" we equate Canada, Australia, New Zealand, Tasmania and South Africa, we have a longer list of non-metric countries, and it comprises not only the most populous, but also the most industrial nations of the world.

Jan 1, 1921

By H. W. Gillett

MAINTENANCE of membership by the technical so¬cieties and the activity of these societies in spite of the adverse business situation have been noteworthy. This forcibly brings home the fact that industry recognizes that sound technical guidance is well worth its cost. The numerous difficulties and losses due to defects of various kinds arising from gas-metal reactions are now generally recognized and interest in these problems is widespread. The forthcoming A. I. M. E. round-table discussion of gas-metal problems will do much to clarify the situation and will permit us to assay our present knowledge and to suggest the proper direction for profitable future research. "The Age Hardening of Metal" was the title of the annual I. M. D. lecture delivered by Dr. Paul D. Merica. A critical review of the known facts relating to age-hardening phenomena was first given, followed by the presentation of a theory correlating the detailed observations which have been made regarding the mechanism of the hardening.

Jan 1, 1933

By AIME AIME

THE 130th Meeting of the Institute was held in Birmingham on Oct. 13 to 15, with visits to other mines and districts before and after. The last visit of the Institute to Birmingham was made in 1888, thirty-six years ago, and vast development has been made in' the district since then. With proverbial southern hospitality compounding over this period of years the welcome given to the Institute was such that .it is difficult to express properly the gratification and appreciation of the visiting members and the officers of the Institute. The Birmingham News in an editorial said: Birmingham is duly appreciative of the presence of these gentlemen, not because they are all distinguished in their great services in the mining and metallurgical world, but for the further reason that our interests are very largely wrapped up in their deliberations. Birmingham is one of the great industrial centers of America. Their discussions are of vital concern to all of us.

Jan 1, 1924

By John D. Sullivan

A DISCUSSION of the developments of the past decade in the field of refractories, and the effect of these developments on the performance and life of open-hearth furnaces, is perhaps best introduced by reference to Fig. 1. This shows the most important types of refractories doing into various parts of the furnace, together with their cost, and remarks on their use. It has been estimated that half of the refractory makers market comes from the iron and steel industry, and something like one-third of all refractory brick used finds its way into open-hearth furnaces. To melt steel, a furnace capable of withstanding temperatures close to 3000 deg. F. is required. The furnace is assembled of various refractory materials selected by experience and economic considerations. Furnace structures today, from a refractory standpoint, are considerably different from a quarter century ago. Furnace operators, interested in the performance of refractories, care little how they are made or where they come from so long as they give reasonable service. But, the entire history of the refractory is important and technical knowledge of the ceramic materials used in making the refractory is necessary to the manufacturers, so that the proper article gets into the hands of the ultimate consumer.

Jan 1, 1936

By Herty, C. H.

Three distinct processes take place during the conversion of iron ore to steel. First: the raw ore is reduced to metallic iron in the blast furnace and during this reduction certain constituents are dissolved in the iron, either through the solution of a solid into a liquid phase, as in the case of carbon, or by reduction of an oxide existing in the slag to the metallic element of that oxide, with subsequent solution of the metallic element in the iron. Thus by the process of solution and reduction, a pig iron results which contains about 4 per cent carbon, 1 per cent silicon, 1 to 2 per cent manganese, 0.1 to 0.4 per cent phosphorus, and 0.03 to 0.10 per cent sulfur. To obtain a sufficient yield of iron from the ore it is necessary that the reducing process be carried as far as possible, with the result that the impurities mentioned accompany the reduced iron. Second: to convert this iron into steel it is necessary to oxidize a part of the iron in eliminating the impurities to the extent desired for the particular product being made. In eliminating these impurities by oxidation a certain amount of iron oxide (FeO) dissolves in the steel. This dissolved FeO reacts with the metalloids, except sulfur, and to eliminate them to the desired extent it is necessary to leave a considerable amount of FeO in the metal. The reaction of iron oxide with silicon, manganese, and phosphorus results in the formation of the oxides of these elements. The oxides enter the slag and the extent of elimination of the elements depends on certain equilibria between the slag and the metal. The reaction of FeO with carbon results in the formation of the gases CO and CO, which, after saturating the metal, pass into the furnace gases. Third: after the iron has been purified to the desired extent as far as the elements listed are concerned, it is necessary to deoxidize the bath to remove the FeO, which is the vital factor in gas formation as the steel solidifies.

Jan 1, 1957