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By Terry Ramsey

INTRODUCTION The Cyprus Pima Mine is located 20 miles southwest of Tucson, Arizona and about fifty miles north of the Mexican border. The Cyprus Pima orebody was discovered in 1950. Feasibility studies were begun in 1952 employing underground development. Economic studies showed open pit operations to be feasible and stripping of overburden was begun in late 1955. The first ore was reached in October of 1956. A 3,000 tpd (tons per day) concentrator was completed and began operation January 1, 1957. From these beginnings, Cyprus Pima Mining Company has expanded into a plant processing approximately 54,000 to 56,000 tpd. Four expansions were required to bring the plant up to its present capacity. Each expansion incorporated what had been learned in previous operation of the plant. The first expansion was completed in August of 1963 doubling design capacity to 6,000 tpd. In reality, because of softer than average ore, capacity was closer to 8,000 tpd. Expansion II was completed in July 1966 bringing design capacity to 18,000 tpd. Expansion III followed immediately. Completed in the summer of 1967, this expansion increased the design capacity to 30,000 tpd. The actual dry tonnage of this portion of the operation in 1974 averaged 38,400 tpd, again, primarily as the result of treating softer than average ore. The latest expansion (Expansion IV), completed in December 1971 and utilizing a semi-autoge- nous grinding circuit, is located in a separate building (Mill II) approximately 200 yards southeast of the original mill (Mill I). Expansion IV was designed for 14,000 tpd, but after circuit modifications, averaged 16,500 tpd in 1974.

Jan 1, 1976

ALABAMA Anniston.-Bretz, J. A. Carrington, F. G. Gerber, A. B. Klugh, B. G. Semple, R. A. Ashland.-Barton, .J. Bessemer.-Abbott, C. E'. Ball, T. L. Beaver, J. J. Ferguson, V. Salmon, H. S. Sehaber, C. F. Whatley, W. J.

Jan 1, 1923

By Don Blackmar

THE production of non-ferrous secondary metals has become a large and important industry in the United States, and deals with practically every type of manufacturing concern.. Its business is unique in that it generally buys from its customers as well as sells to them, whether they are individuals, cities, corporations, or the United States government. Its operations are of vital importance to the success and prosperity of many of the nation's most important manufacturers; yet there are few industries about which less is generally known by those outside it, whether concerning the magnitude of its operations or the details of its actual technique. The industry itself is to blame for this meager publicity, because its technical men have made few attempts to openly exchange ideas, in spite of the excellent examples set by the iron and-steel or the copper and brass industries. Whether this is due to the ancient shroud of secrecy generally supposed to cover smelting operations, or because its technical men actually felt that the industry was too puny to be interesting, is hard to say. This paper will consider its subject in a 'general way, attempting to show something of the size and importance of the industry, as well as its fitness to do its work well. Attention will be called to the sound economic reasons for the handling of non-ferrous wastes by specialists, and to the often unseen losses of metals and labor which occur when manufacturers reclaim' their own metallic wastes.

Jan 1, 1928

By Don Blackmar

THE production of non-ferrous secondary metals has become a large and important industry in the United States, and deals with practically every type of manufacturing concern. Its business is unique in that it generally buys from its customers as well as sells to them, whether they are individuals, cities, corporations, or the United States government. Its operations are of vital importance to the success and prosperity of many of the nation's most important manufacturers; yet there are few industries about which less is generally known by those outside it, whether concerning the magnitude of its operations or the details of its actual technique. The industry itself is to blame for this meager publicity, because its technical men have made few attempts to openly exchange ideas, in spite of the excellent examples set by the iron and steel or the copper and brass industries. Whether this is due to the ancient shroud of secrecy generally supposed to cover smelting operations, or because its technical men actually felt that the industry was too puny to be interesting, is hard to say. This paper will consider its subject in a general way, attempting to show something of the size and importance of the industry, as well as its fitness to do its work well. Attention will be called to the sound economic reasons for the handling of non-ferrous wastes by specialists, and to the often unseen losses of metals and labor which occur when manufacturers reclaim their own metallic wastes.

Jan 1, 1928

By Francis Peabody

THIS paper will not be a technical paper, because, although I have been in. the business of mining and selling coal for 30 odd years, I am neither a mining engineer nor a practical miner. If I digress from time to time from my thesis, I must be forgiven by the expert engineers and highly technical gentlemen for whose proceedings this article is written. Waste of the wonderful store of power that the Creator placed at our disposal appears to have been the theory and the basis of our methods of extracting this power-waste from the time the coal is mined to the time it is consumed. Let us consider the prime causes of this wastage which has been the heritage of the coal mining industry. In the early days-about 150 years after "Stone Cole" was discovered in Illinois by Joliet and Marquette, and Father Hennepin noted a, "sole" mine on his map-the mode of mining prevalent among farmer land-owners, on whose property coal was discovered near the surface or outcropping on the hillsides, was to enter the seam by a shallow shaft or drift into the hillside and remove the coal by wedging it down until a large room was left. The roof without support would fall and our primitive coal operator would then sink another shaft or drive another drift. In these early operations only the large lumps were taken and all small pieces and screenings were left to be covered by the fall of the roof-in fact this condition prevailed in Illinois up to about 1885. Gradually the method of mining changed from the open chamber, to a single entry with rooms turned to the right and left. Later, as the demand for coal increased and the necessity for larger mines became evident, the "room and pillar" system grew to be regular practice.

Jan 5, 1917

By S. H. Ash

THE increasing need for the products of our mines, mills, and processing plants, the loss of mine manpower to plants other than those concerned with the mineral industry, and the drafting of our younger men into military service have created an acute situation in many places as to workers and production. This, in turn, has focused attention on the need for conserving manpower by conserving the health and life of our mining people. Health A world-wide tendency is noticeable in the mineral industry toward protecting the health of workmen,-particularly younger workers, as well as older workers who can continue to produce in many places where manpower is lacking. This matter was emphasized at the Geneva Labor Conference for Coal Mines at the Committee's fourth session, held in Geneva, Switzerland, May 7 through 19, 1951. Papers concerning the health of workers were presented at the annual meetings of the mining sections of the National Safety Council, the Coal Mine Inspectors' Institute of America, the American Public Health Association, and other organizations. Safety Conferences Without exception, the attendance at mining-safety conferences in widely separated places throughout the country during the year was the largest to date. What is needed at the safety meetings throughout the country is more-widespread attendance by those who can sell the idea to the workers that they are the focal point in accident prevention and that safety is not going to be achieved alone or even in part by laws, decrees, or commands, but by quiet influence, unconscious suggestion, and personal' guidance. If these are acquired by the workmen, a safe environment and ample, capable supervision supplied by management, accidents will be fewer and less severe. Many safety conferences attempt to develop the foregoing idea by enumerating and describing training programs for supervisors and workers alike. Nothing can replace a course in first aid for all persons employed at any mine or plant as an introductory and basic step to a successful safety program. Even in this, the shoe must fit the foot, rather than applying the order do this or else. In first-aid

Jan 1, 1952

By H. H. Dievendorff, F. W. Hertel

The method of drilling deep wells into the earth for the recovery of oil and gas is beset with many hazards. This is especially true in the Ventura Avenue field, which has the distinction of being the hardest field in California in which to complete a deep well. The hard, shifting and squeezing formations must be penetrated to great depths in the face of tremendous gas pressures. This field presents problems that keep the operators abreast with all of the latest developments in oil-field tools and machinery and in oil-well drilling practices. Equipment must be strong, and adapted to deep-well drilling and the handling of long heavy strings of casing. High-pressure sands require the utrnost care and attention of the operators and no chances can be taken, since a serious blowout may cause the loss of a well that has cost months of labor and expense. Equipment must meet these requirements or be discarded. Although the deepest wells in the world are not in this field, nor hav:. the longest strings of casing been set, nevertheless, the consistency with which deep wells are drilled and long strings of casing are set places the Ventura Avenue field foremost, in this respect, among the oil fields of the world. The V'entura Avenue field dors claim the deepest commercial oil-producing well in the world, in the Shell Co. of California's "Edison" No. 18. This well was drilled 7015 ft. and came in flowing 3280 bhl. of oil per day. This field also claims the deepest average depth of producing wells in that its Ill producing wells average 5676 ft. in depth. Of these 111 producing wells, 50 arc 6000 ft. or deeper, and 16 are 6500 ft. or deeper. Also, of the 111 producing wells 100 arc flowing, and 11 arc pumping wells. This paper is intended to set forth the methods used in the drilling of deep wells with rotary tools and the handling of long heavy strings of casing in the Ventura Avenue field.

Jan 1, 1928

By Anthony Tuke

Members of the Society of Mining Engineers may well regard it as rather unusual that a paper on this subject is being presented by someone whose first taste of mining came at the age of 60 or so - someone who last heard of cathodes and anodes in 1938. On the other hand, the title does refer to the financing of a mine and at least I can claim to have spent all my business life since the war until 1981 in the world of banking, though this inevitably means that I have been used to looking at these and other problems through what you might regard as the wrong end of the telescope. The lending of money, and more particularly the provision of finance for commerce and industry, is the central job of a banker and I have been involved in this in various ways over many years, but regrettably only very marginally in the world of mining. As you will see from what follows, the rather specialised form of finance which RTZ required was, to my regret, not provided by the British banking community since the great majority of the finance came from American banks and, to a lesser extent, from German banks. I am most indebted to Mr. Roy Wright for a great deal of the nuts and bolts in this paper. He was one of the three central figures in the growth and expansion of RTZ during the 1950's and 1960's and was right at the centre of the negotiations with bankers, with governments and with many others. The going, as you will see, was far from easy. The essential basis for the financing of each of the RTZ group's mining projects was a firm long-term sales contract for sufficient of the output of the particular mine to produce the cash flow necessary to service the loans. Wherever possible, loans were raised in the same currency as the sales contracts were made. Each sales contract was designed to give the customer the product he wanted with a long-term assurance of supply and at the same time to give the bankers the protection they required. Thus the marketing concept and the financing concept for a particular mine formed one overall plan, and talks with the customers and the bankers were conducted in parallel until a satisfactory marketing/financial package was agreed in principle. Preliminary talks were begun soon after the discovery of a potentially viable orebody. As confidence about a discovery increased, customers were persuaded to enter into contingent sales contracts before the very detailed and costly business of the economic and technical feasibility study of the mine was launched; such a study might cost 10% or more of the estimated total capital cost. At the same time provisional understandings were reached with the bankers. The contingent sales contracts usually gave a period of grace of eighteen months to two years, during which time the decision whether or not to continue with the mine had to be made. This decision rested mainly on the result of the feasibility study and also on coming to a firm agreement with the bankers. If all went well and the mine went ahead, then the contingent sales contracts became firm, but they fell away if the decision was negative. The Company was fortunate that during the whole period when its major mines were being developed, world trade was increasing rapidly and Japan was becoming a dominant industrial power. The Japanese supported many of the mines, including Hamersley Iron Ore, Lornex Copper, Bougainville Copper to name a few, with the basic long-term sales contracts that enabled their development. The Germans supported Palabora and to a lesser extent Bougainville. The mines were financed as individual projects generally with a loan/equity ratio of about 65/35, without legal recourse to RTZ for the loans. RTZ was, however, responsible for providing any capital overruns required to bring the mines into commercial operations. Nevertheless, the RTZ management regarded itself as morally responsible to the lenders because, Palabora aside, the sales contracts had either a fixed selling price (like Hamersley), an indexed price (like the Elliot Lake Uranium Mines and Mary Kathleen), or a floor price (as in Lornex, Bougainville and Rossing). Thus the Company believed that any financial failure would have been due to poor management or technical

Jan 1, 1985

By Donald W. Scott

Generally speaking, there is nothing very difficult about taking good microgrztphs of photogenic thin sections or grains with a petrographic microscope-camera setup. However, sometimes it is desired to show some detail that cannot be illustrated satisfactorily by the usual micrographs taken with parallel polarized light, with crossed nicols, or even with two micrographs. A simple procedure giving good results has been used at Battelle Memorial Institute for subjects falling into this classification, and it is believed to be of interest, especially to research people who must sell a point to executives through the medium of well-illustrated reports. The following problem illustrates a typical application: It is desired to photograph a thin section of an iron ore to illustrate the character and association of the iron oxides and the individual quartz crystals. A magnification of 75 dia. is acceptable. A micrograph of the field in question (Fig. Ia) was taken with parallel polarized light. Due precaution was taken to provide critical illumination, correct exposure, a sharp focus, a good darkroom technique, and other essential conditions. It illustrates correctly the iron oxides, but it fails to show the individual quartz crystals. A micrograph of the identical field (Fig. Ib) was taken under the same precise conditions, but with crossed nicols. It gives a better idea of the character of the individual quartz crystals but is likely to be misinterpreted unless accompanied by a lengthy descriptive note. This micrograph suggests that the centrally located, large black area is composed entirely of iron oxides. That this' is an incorrect interpretation is evident by reexamining the micrograph of Fig. Ia. The correct interpretation is that the dark area contains quartz crystals oriented with their optical directions parallel to, or nearly parallel to, the vibration directions of the polarizer and analyzer of the microscope. Thus, the executive, or anyone who had not done the work personally, would get no more than a fair interpretation, even if two micrographs were included; and in the interests of both brevity and clarity, one micrograph usually is more desirable. Exactly how many quartz crystals occur in this region cannot be told from the two micrographs, and a printing of the two negatives in register would likewise not show the detail desired. Thus, it is evident that some subjects cannot be satisfactorily illustrated by the usual procedures. In photographing Fig. Ic the light was subdued and, during the entire exposure of 75 sec., the analyzer nicol was rotated uniformly in its mounting from a crossed position to 45° uncrossed position to introduce the desired amount of contrast in the various individual quartz crystals. The true reproduction of the character and association of the iron oxides, and the additional structure and detail in the quartz areas, is apparent. It might be

Jan 1, 1949

By Donald W. Scott

Generally speaking, there is nothing very difficult about taking good microgrztphs of photogenic thin sections or grains with a petrographic microscope-camera setup. However, sometimes it is desired to show some detail that cannot be illustrated satisfactorily by the usual micrographs taken with parallel polarized light, with crossed nicols, or even with two micrographs. A simple procedure giving good results has been used at Battelle Memorial Institute for subjects falling into this classification, and it is believed to be of interest, especially to research people who must sell a point to executives through the medium of well-illustrated reports. The following problem illustrates a typical application: It is desired to photograph a thin section of an iron ore to illustrate the character and association of the iron oxides and the individual quartz crystals. A magnification of 75 dia. is acceptable. A micrograph of the field in question (Fig. Ia) was taken with parallel polarized light. Due precaution was taken to provide critical illumination, correct exposure, a sharp focus, a good darkroom technique, and other essential conditions. It illustrates correctly the iron oxides, but it fails to show the individual quartz crystals. A micrograph of the identical field (Fig. Ib) was taken under the same precise conditions, but with crossed nicols. It gives a better idea of the character of the individual quartz crystals but is likely to be misinterpreted unless accompanied by a lengthy descriptive note. This micrograph suggests that the centrally located, large black area is composed entirely of iron oxides. That this' is an incorrect interpretation is evident by reexamining the micrograph of Fig. Ia. The correct interpretation is that the dark area contains quartz crystals oriented with their optical directions parallel to, or nearly parallel to, the vibration directions of the polarizer and analyzer of the microscope. Thus, the executive, or anyone who had not done the work personally, would get no more than a fair interpretation, even if two micrographs were included; and in the interests of both brevity and clarity, one micrograph usually is more desirable. Exactly how many quartz crystals occur in this region cannot be told from the two micrographs, and a printing of the two negatives in register would likewise not show the detail desired. Thus, it is evident that some subjects cannot be satisfactorily illustrated by the usual procedures. In photographing Fig. Ic the light was subdued and, during the entire exposure of 75 sec., the analyzer nicol was rotated uniformly in its mounting from a crossed position to 45° uncrossed position to introduce the desired amount of contrast in the various individual quartz crystals. The true reproduction of the character and association of the iron oxides, and the additional structure and detail in the quartz areas, is apparent. It might be

Jan 1, 1949

By B. F. Tillson, C. M. Haight

I. General Remarks..........................723 1. Location............................723 2. Characteristics of the Orebody..................725 (a) Mineralogical (b) Shape, Strike, Dip, Size, Etc. (1) Ore (2) Country Rock 3. Historical Sketch........................725 11. Mining Method..........................726 1. Outline of Methods Now in Operation............... 726 (a) Stopes (b) Fill . (c) Pillars (d) Slices (e) Transportation (f) Miscellaneous 111. Mining Operations........................727 1. Shaft..............................727 (a) Sinking (b) Dimensions and Equipment, Sketches (1) Size, Inclination. Direction, Etc. (2) Timbering (3) Stations (4) Track (5) Hoisting Equipment (a) Skips (b) Engines and Ropes (c) Idlers (d) Man Cars (6) Loading Pockets (a) Operating Figures (7) Headframe

Jan 1, 1918

By Howard Evans

Moderate but substantive gains were recorded in 1972 in the minerals processing industry. In the area of mill design, a number of large plants under construction during the past two to three years were tuned up and went into production. The application of operating controls has also made some significant strides. Progress here has been made in the areas of on-stream particle size analysis, on-stream x-ray analysis, slurry transportation, tripper control, flotation reagent control and digital control of grinding circuits. The major contributions to improved equipment are coming from smaller specialized equipment makers.

Jan 2, 1973

By W. R. Bull, J. R. Roos

A method is described whereby the true financial value of each constituent of each concentrate can be calculated. Each value is then compared with what this value would be in a perfect separation. The difference in each case represents the loss incurred by each aspect of an inefficient separation. The relative magnitudes of these losses indicate those avenues of plant investigation and research that offer the highest potential reward. The metallurgical efficiency of a concentration operation is difficult to express because there are two criteria of performance, namely, grade and recovery. Neither of these alone gives any indication of the effectiveness of an operation and, if they are combined in some formula, it must be empirical and unreliable because of many external factors. Since milling is an operation performed as one step in the most profitable overall method of producing a metal or other end product, the main objective of mill operation should be to make a maximum contribution to this maximum profit. When concentrates are sold to custom smelters, the income from the operation, and the costs, may be calculated. When concentrates are further processed by another division of the same company, and there is no formal financial relationship between, say, the milling and smelting divisions of the company, the mill superintendent's job is less well defined. But even so, if the mill superintendent works as though he were selling his concentrates, and uses reasonable, if fictitious, conditions of sale, then he can get a good indication of the effectiveness of his operation by calculating his "Economic Recovery". ECONOMIC RECOVERY This is a method used as a basis of operation by several mills and has been described in the literature. Very briefly, the "standard" of operation is taken as that of a mill separating the ore into perfectly pure concentrates with 100% recovery of each mineral in its respective concentrate. For example, a 4%Pb, 4% Zn ore (galena and sphalerite), would provide a lead concentrate weighing 4.62% of the feed and assaying 86.6% Pb and a zinc concentrate weighing 5.97% of the feed and assaying 67.1 % zinc. These perfect concentrates are (hypothetically) shipped to the appropriate smelters, freight and treatment charges and payments calculated, and the net return obtained. This is the optimum financial return for the operation of the mill and is used as the standard. Now the return for the actual, real-life, mill operation is calculated in the same way, and the ratio of the two is termed the Economic Recovery. Many additions and modifications may be made in any particular case. For example, if the zinc mineral is marmatite, the optimum grade of the zinc concentrate may be set lower than 67.1%. If silver is present, it will be recovered 100% in the lead concentrate in the perfect operation. Similarly, cadmium will be recovered 100% with the sphalerite. Mr. Weiss' paper' mentions a case where, because of extremely fine intergrowth between the valuable mineral, chalcocite, and pyrite, the optimum grade of copper concentrate was taken as 45% Cu instead of the theoretical 80%. Each operation will present its own possibilities in this way.

Jan 1, 1970

By C. S. Simons

The conversion of a successful research and development effort into a money-making business venture requires careful attention. Problems of a business nature, such as market size, product selling price, raw materials and fuel availability and cost, financing factors, local and national taxes, licensing arrangements, etc. must, of course, be considered and resolved. In addition, the technical questions involving the scale-up of pilot plant or laboratory results to the full-scale plant must be resolved in order to avoid the financial disaster that attends a major delay in the startup of a commercial facility. The very difficult and demanding task of providing the interface between the research laboratory and the profitable metals processing plant will be discussed with examples from the author's extensive experience. After I had accepted the invitation to present a paper on the above subject of the interface between R & D and production operations, I began to give some serious thought to the subject. The program chairman had told me, in conveying the invitation, that what the committee had in mind was a discussion of positive and negative, forces in that interface, based on "gray-hair" experience. I am, therefore, at least physically qualified! My first reaction was one of mild shock; after over twenty years in the direct pursuit of the conversion of research and development findings into plant operations, I had never tried to sort out my , experience into a formal system of DO'S and DON'TS for the edification of posterity. However, after a little further reflection, I realized that this carries no stigma. No one has been able to formulate such a set of rules, and it is not really very likely to be done. Particularly if they are to be practical. I shall therefore settle for a more modest goal; I will simply discuss the factors that I have come to believe are the most critical in insuring that re- search and development results are converted into successful operation.

Jan 1, 1973

By Henry M. Rowe

Professor Ruff's most illuminating paper' describing his extremely valuable investigation of the carbon-iron equilibrium diagram assigns definite temperatures to certain very important lines in the diagram, viz.: the eutectic temperature EB (Fig. 1) and the " near-eutectic " temperature E'B', but without indicating clearly enough the reasoning which warrants these assignments. These temperatures are of such primary importance that it is well to indicate the apparent gaps in the reasoning, in the hope that they may be filled in. In his diagram, Fig. 1, the point X and the liues B'D'lII represent the experimental results reached by Ruff and Goecke;a AB, AEB, and SE represent the liquidus, the solidus, and the solubility of the carbon in solid austenite in the absence of graphite according to Gutowsky,3 AB being also in accordance with Spiecker's data; S'E' the solubility of carbon in solid austenite in the presence of graphite according to Ruer and Iljin;5 GS the line A3 after Ooerens and Meyer; 6 and EBC the true eutectic line as inferred by Prof. Ruff from Gutowsky's data. B'D' is the carbon content found in cast-iron which had apparently saturated itself with carbon in the presence of the graphite of the enclosing graphite crucibles in which the determinations were made. From its straightiiess and its sharp inflection near 6.67 per cent. of carbon, the carbon content of

Jan 1, 1913

By Francis N. Flynn

Many excellent papers, descriptive of the milling and smelting of every kind of commercial ores, the refining of virgin metals, the casting into various shapes demanded by the trade, the rolling into shapes best suited to the factory machinery and the making of composition alloys to suit every requirement have been issued by the many technical societies dealing with non-ferrous metals. It is a wonderful collection of papers, of which the mining and metallurgical engineers may well be proud, but strange as it may seem, metallurgists in general appear to take the stand that when they have delivered suitable alloys to the foundry and rolled products to the factory their duty to write papers has ceased, at least in so far as the A. I. M. E. is concerned. Still we read in the daily papers that the mining companies are absorbing metal-manufacturing industries. The purpose of this paper is to describe the reclaiming of non-ferrous scrap metals at manufacturing plants, taking as an example the automobile industry. Collection and Disposition of Scrap Until about five years ago, much of the factory scrap, with little or no preliminary treatment, was sold to secondary-metal smelters. Of late years the factory salvage department has become an important part, of the plant in reclaiming everything of value and incidentally does much of the work formerly done by the smelters. Like most good things, it is sometimes overdone, and much work is done at the factory with inexperienced men that could be done much better by experienced skilled labor at the custom smelting plants. Employees of the salvage department collect the waste products in all departments at the source and in that way avoid much contamination. Every reasonable precaution is taken to keep the scrap clean. It is hand-sorted, cut, burned, magnetized, concentrated, separated or compressed, as the case may be, preparatory for re-use in the plant or for selling to others.

Jan 1, 1930

By M. R. Campbell

Coal is the geological product of entombed vegetal tissues. This view of its origin led Stopes and Wheeler to define it as "mummified plants." They evidently intended this term to be used in a broad way and to mean the preservation of the organic material, as such, regardless of the means employed to accomplish the purpose. The term " coal" should be regarded, therrfore, as broadly generic, and applicable to all accumulations of vegetal tissues as soon as they are covered and protected either by water or by earthy material. In this sense peat should be regarded as the first stage of coal formation and the term coal should include the resultant products of transformation in all other stages of the process until they have lost all resemblance to the original matter from which they were derived. If this idea of the development of coal is accepted and it is admitted, as the geologists claim, that the forces which produced this transformation of the coal have been active since vegetation began to grow upon the land, and are still in operation, it is obvious that somewhere in the world there are all gradations of this material from peat just forming in the swamps of today to graphitic anthracite which presumably marks the most advanced stage that can be recognized with certainty as belonging to the series. Some of these coals, particularly those occurring in the upper part of the series, are fairly well known because they are the ones that are most widely distributed and have been mined and utilized most extensively. On the other hand, the coals in the lower part of the series are but little known because they are not so abundant and, owing to their relative inefficiency, have been only slightly exploited and utilized, especially in regions where the better coals are abundant. The result of these conditions is that much research work has been done on coals of the higher ranks and a great body of facts regarding their physical and chemical properties and the uses to which they are best adapted has been accumulated, but little information is available regarding the coals of the lower ranks. Many able scientists, particularly chemists, have attempted to bring some order of the chaos of coals of various compositions and uses by

Jan 1, 1930

By Reno Sales

INTRODUCTION. THE geology of Butte possesses especial interest on account of the magnitude of the ore deposits, their extraordinary richness and persistence in depth. Since its discovery in the early 60's the district .has yielded, in round numbers, 6,000,000,000 lb. of copper, 260,000,000 oz. of silver, 1,250,000 oz. of gold, and a large but not definitely known number of pounds of zinc. This enormous metal production has been derived from an ore tonnage estimated roughly at 65,000,000 tons. At the present day, most of the important mine shafts have reached a depth of. 2,400 ft., while several are more than 3,000 ft., deep. At these-great depths rich bodies of copper ore are being exploited, showing no diminution in metal content as compared with the ores of the higher levels. The present (1913) daily rate of production is approximately 14,000 tons, of which 13,250 tons may be regarded as copper ore, although a small percentage of this is minable only because of the presence of

Jan 8, 1913

By Robert L. Bates

Definition An industrial mineral, says the Glossary of Geology, is "any rock, mineral, or other naturally occurring substance of economic value, exclusive of metallic ores, mineral fuels, and gemstones; one of the nonmetallics." Probably most geologists and engineers would accept this simple and straightforward definition, at least as a general statement. On analysis, however, certain anomalies crop up. For example, it may be considered arbitrary to include industrial diamond and corundum and to exclude their precious varieties, gem diamond and sapphire. So the present volume has a section on gems and gem materials, in spite of the definition. Another problem arises when we try to define precisely what is metallic and what is nonmetallic. Bauxite and ilmenite certainly qualify as metallic ores, but both are also raw materials of important nonmetallic substances; hence they are included in the book, A third anomaly is that, by common consent of geologists, engineers, mineral economists, and others concerned, the term industrial minerals may include not only rocks and minerals but also certain manufactured products like cement and lime, and even mixed groups of natural and artificial products, such as abrasives and refractories. Thus the central realm of the industrial minerals is clear enough, but its boundaries tend to be indefinable. Since a definition that allowed for every irregularity in the outer fringes would be excessively unwieldy, the one quoted above may be considered satisfactory. The expression industrial minerals is commonly equated with nonmetallics, and with the somewhat more precise phrase industrial minerals and rocks as in the title of this book. Characteristics of the Field The industrial minerals as broadly interpreted are a highly diverse group of materials; indeed, we may say paradoxically that diversity is about all they have in common. At one end of the spectrum are ordinary earth materials such as gravel and crushed stone, with a value of perhaps $3 per st; at the opposite end are industrial diamonds, which sell (by the carat) at the rate of roughly $18,000,000 per st. Neither the metals nor the fuels, and few if any categories of manufactured products, include items that differ in value by more than six orders of magnitude. Most gravel and stone are of no value unless close to a market; diamonds and other exotic substances possess such unique and desirable properties that their occurrence in remote corners of the earth is no deterrent to their use. The broad range of industrial minerals falls between these extremes of unit value and place value. The industrial minerals penetrate the entire fabric of modern industrialized society, from such fundamental operations as drilling for oil and smelting iron ore to the manufacture of virtually the whole array of consumer products. There is no industrial-minerals industry; there are many industries. The simple term field is convenient as an all-inclusive expression. An industry is considered to belong in the industrial-minerals field if its operations consist of extraction and processing, but not manufacturing. Thus the mining and beneficiation of feldspar is a mineral industry, but the manufacture of ceramic products is not. In the cement and lime industries, processing merges into manufacture, and the line is less distinct. It disappears altogether in a plant that extracts salt as artificial brines, and makes sodium and chlorine chemicals, all under the same roof. An aspect of some industrial minerals that differentiates them from the metals is that their physical properties carry over into ultimate use of the product. Such minerals as mica, asbes-

Jan 1, 1983

Department of Conservation and Development, State of North Carolina, Raleigh, N C H J Bryson, State Geologist. The latest list of publications will be sent upon request. Of the many Bulletins, Economic Papers, Circulars and Volumes issued by the Department of Conservation and Development, the following are available and relate to mining and geology of the state ? Bulletin 18, Bibliography of North Carolina geology, mineralogy and geography (1909), 50 cents, 21, The Gold Hill mining district (1910), 15 cents, 22, Report on Cid mining district (1911), 15 cents, cloth 75 cents, 25, Zircon, monazite and other minerals, 15 cents, cloth, 75 cents, 28, Limestones and marls, 15 cents, 29, Kaolins of North Carolina, 50 cents, 31, Deposits of brown iron ore, 50 cents, 32, Magnetic iron ores, 15 cents, 33, The Deep River coal field, 50 cents, 37, Pyrophyllite deposits, 35 cents A series of the Economic Papers review the mining industry in North Carolina for the years cited Those now available are Economic Paper 23 (1908-1909-1910), 10 cents, cloth, 50 cents, 49 (1913-1917), 20 cents, 55 (1918-1923), 25 cents, 60 (1924¬1925), 15 cents, 63 (1927-1928), 25 cents. Other available Economic Papers on geology and mining are No 3, Talc and pyrophyllite deposits (1900), 25 cents; 58, Oil prospecting well near Havelock (1927), 5 cents, 59, Oil-bearing shales of Deep River Valley (1927), 10 cents Available volumes on geology. Vol 1, Corundum and the basic magnesian rocks (1905), 35 cents, cloth, $150, 5, The Cretaceous formations of North Carolina (1923), cloth $1 75

Jan 1, 1933