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By A. H. Daane, J. J. Hanak, F. H. Spedding

IN the study of the rare earths at the authors' laboratory, methods have been devised for preparing pure rare earths and many of their properties'- have been determined. Very little information is found in the literature on the properties of europium metal, which is the scarcest of the naturally occurring rare earths. Since we have recently prepared europium in appreciable quantities, we are in a position to describe the method of preparation and some of the properties of this metal. Metallic europium was first prepared by Klemm and Bommera who heated a mixture of potassium and EuC1, in vacuo, and obtained a mixture of europium metal and KC1. Trombe4 electrolyzed a molten salt bath containing NaC1, KC1 and EuC1, and collected the europium in a molten cadmium electrode as a cadmium alloy. The cadmium was subsequently removed by distillation but the properties of the residue indicate that pure europium was not obtained. McCoy attempted to prepare europium by distilling mercury from europium amalgam, but the stability of the Eu-Hg intermetallic compounds prevented a complete separation of the two elements. The preparation of very pure europium was suggested by previous work in this laboratory1,4 in which ytterbium and samarium were prepared by heating the respective sesquioxides with lanthanum metal turnings to 1450°C in vacuo and distilling ytterbium and samarium from the mixtures. Subsequently, small test experiments showed that europium also could be prepared by this method. A more detailed version of this method was used in the work described in this paper. Klemm and Bommer3 found by X-ray analysis that the metal had a body-centered cubic (bcc) structure with a lattice constant a, = 4.582 ± 0.00A (converted from kX units), with a bulk density of 5.30 g per cu cm. They found europium to be weakly ferromagnetic. Spedding, et al,7 found a,, to be 4.606 ± 0.001A. Barrett' showed that the bcc structure persists throughout the temperature range 5 to 3000K with a, at 5, 78, and 300°K being 4.551 ± 0.003, 4.551 ± 0.004 and 4.577 ± 0.001A, respectively. Trombe1 described europium as being iron gray, malleable, about as hard as neodymium and not attacked by cold water. He estimated the melting point to be between 1100 and 1200°C. Previous work in this laboratory indicated that the pure metal corrodes rapidly in air and reacts with cold

Jan 1, 1959

By N. S. Kim

Silver paste including nano sized particles maintains conductivity in high temperatures without forming oxide layers. In the industry, printing process produces wasted silver paste inside the cylinder and on silk-screen. Pyrometallugical silver recycling methods have environmental problems and do not extract pure silver after removing polymer and organic materials during the extraction process. In this study a simple wet process, of recycling the waste silver paste, using ammonia, was conducted. Silver ion extraction yield was increased using oxidant in the ammonia solution. Possible extraction yields, such as pH, concentration, temperature of ammonia, oxidant concentration and the extraction time. The particles that were obtained after the extraction process will be used as porous hydrophobic catalytic and applied to AI mask and hydrophobic ink. Keywords: Waste silver paste; Ammonia; Hydrophobic porous support

Jan 1, 2009

By Frank A. Hill

After a long struggle with an underground mine-fire and its accompanying evils, having experienced the discouragement of many retreats, the uncertain hope of varying advances, and the gratification of final success, I am tempted to give the members of the Institute some of the details of the fight. I do not write with the thought of treating a novel subject, but with the hope that some one as unfortunate as ourselves may be led by our experience to avoid our mistakes and to profit by our successes. The fire occurred on June 16, 1890. It was a calamity awful in its results, ringing the death-knell of thirty-one stalwart miners, bringing sorrow and desolation to many homes, and destroying in a few hours the work of years. While there have been a number of disasters in the history of American mining in which there was a greater loss of life and property, I know of none in which so simple a cause led to results so serious. A description of the mine, with the details of the accident, is necessary for a full understanding of the conditions existing at the time. The Hill-Farm-Parrish mine is in Dunbar township, Fayette county, Pa., about one mile from Dunbar station, on the Pennsylvania and Baltimore & Ohio railroads, about four miles south of Connellsville, nine miles northeast of Uniontown, and in the heart of what is celebrated as the Connellsville coke region. The mine is owned and operated by the Dunbar Furnace Company ; and all the coal produced is made into coke and used in the company's furnaces, one mile to the east. The mine is opened by two slopes, the HillFarm and Parrish, the latter known also as the Ferguson. The Hill-Farm slope is 2600 feet northeast of the Parrish. There are 150 ovens at the former and 70 at the latter slope. The Hill-Farm slope is 4100 feet in length, and the length of the Parrish at the time of the accident was 3700 feet. The average dip of the coal is about 8 degrees S of W. The workings of the two slopes are con-

Jan 1, 1893

By P. A. Fisher, J. B. Wilson, D. J. Whitehead, C. J. P. Ball, A. C. Jessup

The properties of a new magnesium alloy ZT1 containing 3.0 pct Th, 2.5 pct Zn, 0.7 pct Zr are described. The alloy possesses good creep and fatigue resistance up to 650°F, is free from microporosity, and is readily sand-cast. ZT1 is shown to be superior to zinc-free Mg-Th-Zr alloys. THE advent of the jet engine created a demand for a light sand-casting alloy capable of being cast into large complex shapes and capable of resisting creep at temperatures up to 500°F. This demand has been largely met by alloys of the magnesium-cerium mischmetal-zirconium types, containing about 3 pct Ce mischmetal and 0.7 pct Zr, typified by Elektron magnesium alloys MCZ and ZREI, the latter alloy also having a zinc addition of 2.5 pct. These alloys utilize the valuable properties at elevated temperatures conferred by the addition of rare earth metals to magnesium, a fact which has been known for many years and discussed by several investigators.1-1 Murphy and Payne8 showed that the addition of the powerful grain-refining element zirconium to Mg-Ce mischmetal alloys produced alloys with attractive room temperature properties combined with good creep properties and castability. With the increasing power of modern jet engines the temperatures to which some of the magnesium parts are subject are likely to exceed the safe working range of the cerium-mischmetal-containing alloys, and at the beginning of the research considerable interest had been shown by aeroplane engine designers in a magnesium sand-casting alloy suitable for service at higher temperatures, e.g., 600°F and above. At an early stage in the development of this type of alloy a check on the fatigue properties at elevated temperatures indicated that, since the fatigue limit even at 108 eversals was appreciably higher than any permissible creep stress, the main emphasis of the research could be concentrated on creep behavior. The primary aim in developing the new alloy has therefore been to attain maximum creep resistance; but due consideration has also been given to other important properties such as castability, tensile strength, and cost. It is by now well established that it is not possible to correlate creep strength with other short time mechanical properties such as are obtained in tensile

Jan 1, 1954

By C. K. Leith

At the outset I would like to make it clear that I do not enter this discussion in a controversial spirit, but in an attempt to contribute something helpful to an understanding of a difficult problem. I have too high regard for the- sterling quality of the work of the men who have studied this subject in detail to offer anything in the way of essential contradiction to their statements of fact. Difference of opinion arises from differing valuation of the possible alternative hypothesis which these facts suggest. Some degree of recrystallization in limestone contact zones has been recognized by many investigators. Earlier investigators, for the most part, assigned an important, if not the most important, ro1e to recrystallization in development of these zones. With the growing recognition of introduction of ores and gangue materials into the contact zone from igneous rocks through the medium of primary magmatic solutions, there has been a tendency to ascribe to this process most, if not all, of the chemical and mineralogical characteristics of the contact zonc. This has involved a correspondingly diminished emphasis on recrystallization of substances already there as a factor in the process, and in some cases even the complete elimination of this hypothesis. From detailed study of a few contacts, casual observation of others, and a general familiarity with the literature, some of us have been led in recent years to raisc the question whether the pendulum has not swung too far away from recrystallization toward direct introduction from igneous sources, and to argue for more recognition of the part played by recrysta11ization.l The inevitable sequence has been that those of us who have .taken this view have been charged, at least by inference, with emphasizing recrystallization to the total exclusion of the alternative process. Scientists, like other men, like to classify and pigeon-hole views under simple and definite designations, leaving out qualifications which would tend to make the classification more difficult to state. This has made the problem seem more definite and simple, but has tended to obscure the fact that the disagreement is primarily not one relating to essential facts, but one of

Jan 1, 1915

By Edwin Ludlow

For many years, coal has been known to exist in the valley of the Sabinas river, in the State of Coahuila, and for about 15 years it has been worked by the Mexican International Railway Co., which opened mines for its own fuel-supply when the railway was built, and has been mining continuously ever since. The coal-basin worked by this company lies along the Sabinas river, principally on the SW. side. It covers a wide area and has been carefully prospected, but only in a few parts have the beds been found sufficiently thick and regular for economical operation. This Sabinas basin was considered the only one in this field, until, in the Spring of 1899, the Las Esperanzas basin was found by Messrs. J. L. Elliot and E. D. Peters, who were in Mexico looking after some copper-properties. After a further examination by Mr. James T. Gardiner, of New York, the Mexican Coal & Coke Co. was organized in June, and active work was begun on Nov. 5, 1899. The coal-field of Las Esperanzas, situated in the State of Coahuila, about 85 miles SW. of Eagle Pass, Texas, adjoins and runs parallel with the Sabinas basin—an anticlinal separating the two outcrops by about 2 miles. Fig. 1 is a sketch-map of a part of the basin. The coal-formation is in the Upper Cretaceous, and corresponds with the Laramie measures of the United States. The following geological section, taken in Nogales canon, shows the measures between the massive limestones forming the Sierra de la Santa Rosa and the outcrop of the coal: Section. Feet. Limestone,...Unknown. Blue shale,.........110 Shale and sandstone,.. 60 Bed of fossiliferous shale,. 60

Jan 1, 1902

William B. Phillips, Birmingham, Ala.: The questions raised by Messrs. Wilkens and Nitze are in the highest degree interesting to owners of low-grade iron-ores, aizd no less so to blast-furnace managers. If it can be shown that ores heretofore considered worthless can be brought within the limit of economic use, many large and readily accessible deposits may come into market on the one hand, while on the other the possible increase in the output of the furnace per ton of ore used will prove of advantage to the iron-maker. It cannot, of course, be claimed that this process has been employed on a working-scale with respect to iron-ores, and in so far as concerns results on a large scale no one is any wiser than his fellow. Granting that the results obtained in an experimental way (and certainly the experiments were conducted with a great deal of care) can be attained in practice, we would still be facing the question, what it would cost to get them. In the absence of any specific data, we have to fall back on general principles, helped along, as far as possible, by indications afforded by the experiments. I must confess that as regards the Clinton ores, which I have studied to some extent, I am not sanguine of making a ton of 53 to 54 per cent. concentrates from less than 1.75 tons of 40 per cent. raw ore. It may be possible to get the iron in the heads to 56 to 57 per cent., but the lesser richness of the middlings will probably reduce this to 53 to 54 per cent. in the salable stuff. As the authors remark, it is not worth while to discuss the concentration of the better grades of " soft" Clinton ore; for the price at which they are now delivered at the furnaces, and the comparatively limited amount now remaining, render their concentration unadvisable. If it is to succeed in the Birmingham district, the process must be applied to the low-grade soft and hard ores now con-

Jan 1, 1897

By Rudolph Gahl

RUDOLF GAIL, Miami, Ariz.-Since I wrote the paper on flotation which is in your hands, important developments have taken place, and, for this reason, I will try in a few words to bring it nearer up to date as far as the Inspiration plant is concerned. You, may have noticed that in the Inspiration concentrator, flotation is not solely relied upon for the recovery of the coarser material, but that flotation tailings are split into a sand and a slime product on drag classifiers. The sand product is treated on tables which thus supplement the work of the flotation machines. Extensive tests have shown, us that, if we wanted to, we could leave out these tables and substitute additional flotation machines, as they will make fully as good, if not a better recovery than tables on the deslimed feed, but the treatment would be more expensive, especially in view of the fact that oils are required which cost more than those which we are now using in our main flotation plant. We have, however, decided to apply flotation treatment to our table middlings. I would also like to add a few words regarding the treatment of oxidized copper ores. Although our experience shows that the addition of hydrogen sulphide and other soluble sulphides effects a very good recovery of copper carbonates with certain ores, we have not been able to prove that we could use it advantageously for the ore mixture which we are treating in our concentrator, and for this reason, have looked toward leaching for extracting the carbonate and silicate copper that we are losing now. Experiments in this direction are going on and are giving very encouraging results. It may interest you to hear that we intend to use limestone for the precipitation of the copper which goes into solution, as electrolytic precipitation seems to be out of the question on account of the diluteness of the resulting solutions, and precipitation by iron was rightly objected to on account of the unavoidable contamination of the water supply. We feel very hopeful about the success of our limestone precipitation which, if it holds what it seems to promise, will develop into a novel feature of copper metallurgy.

Jan 10, 1916

By Henry E. Armitage

The object of this paper is to give a few useful hints on the concentration of low-grade ores. The machines that I shall speak of are, Cornish rolls, revolving screens, Hartz jigs, spitz-lutte, and the Linkenbach buddle (or Roberts's patent buddle, as it is called in Colorado). I think the reason why some of them have been discarded in favor of more recent inventions is that they have not been given a fair chance to do their work in a satisfactory manner. Cornish rolls are usually looked upon as a machine designed simply to crush the ore as a preliminary to sending it to the sizingscreens, beyond which they have nothing to do with dressing the ore. On the contrary, the rolls give the key-note to the whole process. It is well known that one class of rock will crush differently from another, and from the result obtained by passing the ore through the rolls the size of the first revolving screen and the surface required on the jig-screens must be determined. If it is found that the mineral crushes clear from the quartz, a large mesh can be used on the first sizing-screen, and the tailings will not require recrushing ; but if it is found that some of the tailings from the first jig are ragged (that is, are carrying off particles of mineral sticking on the quartz), it will be necessary to recrush them. Again, if a large percentage of the tailings carry off mineral, it will be more economical to commence with a finer mesh screen than to recrush the tailings. Having determined the best mesh to use on the first sizing-screen, the different sizes on the other screens can be determined from it. I have found for practical purposes that, commencing with a 6-mesh, the next should be 8, then 12, and finally 18. The holes in the jig-screens should be a trifle larger than in the revolving screens. For instance, if the revolving screen is made of No. 14 wire, the corresponding jig-screeus should be of No. 16 wire. The jig-screen surface required for each size made depends on the may

Jan 1, 1890

C. W. GOODALE, * Butte, Mont.-In regard to the employment manager, the North Butte Mining Co. has undertaken that line of work and the rest of the companies are watching the experiment. If it is proved to be the proper thing, the system will be introduced into other mines. We have to combat the opposition to the use of the "rustling card. It is nothing more nor less than asking the nationality, where the plan formerly worked, and whether he is married or single. ROBERT RHEA GOODRICH, Anaconda, Mont. (written discussion?).¬Since the efficiency of the different phases of personnel work employed by industrial concerns, which are bringing about greater efficiency and lessening the labor turnover, the latter being intimately connected with "contentment of mind," depends on the individual workman, it is highly desirable, as far as industry is concerned, to keep the workman's mind and body in trim in order to lessen accidents and produce a higher grade of work. Prevention being better than cure, health supervision of the workmen during employment should be maintained by the employers in order that mental alertness and physical well-being may be obtained. I have long believed, from observation in many plants, that when any problem is dependent on the individual workman, what he believes and what he does is vitally dependent on his health. I will follow with much interest what is to be clone in the future in relation to the subject of health supervision during employment (as well as medical examinations at the time of employment), and I hope this idea will be generally instituted in personnel work. A workman with good health and a contented mind should be an ideal component of a progressive industrial concern. The contentment of the workman is fostered by a number of admirable phases of welfare work which are being still further developed. The mental and physical well-being of labor should be the issue in Labor vs. Capital in the new period of the industrial promotion of the United States into which we are now entering.

Jan 4, 1919

By Campbell M. Hunter

Petroleum is found in almost every province in Persia. On the northern frontier, along the southern shore of the Caspian Sea, it is found near Enzelli and Shakhtesar and gas at Khoremabad. Oil is also found at Gumish Tepe, northwest of Astrabad, on the southeastern shore of the Caspian Sea. Further inland, to the south of Astrabad, oil is found at Dehahkuh-i-balae, also on the margin of the Khorasan desert at Semnan, 115 mi. (35 m.) east of Teheran. Along the western frontier, from northwest to southeast, oil is encountered at Ouschachi, north of Lake Urumieh; in the province of Azerbaijan, at Zohab, Khanikin, and other places in. the district of Kormanshah in the province of Ardelan. Further south, in the province of Luristan, oil is found east of Mendeli and in the Pusht-i-kuh districts. Considerable quantities of oil are also obtained from Schuster, Maidan-i-Naphtun, Ram-Hormuz, Beheban, which are almost on a straight line, running northwest and southeast along the foothills of the Bakhtiari Mountains. At Ahwaz, in the province of Arabistan, oil has been found along another range of hills whose axis also lies in a northwest-southeast direction. In the Fars province, boring for oil has taken place at Daliki, and indications of oil are found at Kheri, Fasa, Darab, and other places. A gas show is also recorded at Kuhi-Sung-Atush in this province, 30 mi. (48 km.) east of Darab. In the south of Persia, oil is encountered on Qishm Island, also at Ahmedi and other places north of Bunder Abbas. On the southeastern frontier, oil is found on the Sarhad range of hills. Thus, oil indications have been noted over a distance of approximately 1100 mi. along the western and 700 mi. along the northern frontiers of Persia. History The first working of oil in Persia of which there is any record took place at Kir-ab-US, Susiana, now known as Kiab, about 57 mi. northwest of Schuster. Herodotus (about B. C. 450) reported a well near Ardericca that produced three different substances; namely, asphalt, salt, and oil. The oil, which was black and had a strong smell, was called Rhadamance by the Persians.

Jan 1, 1921

By Ralph Wilcox

THE diamond drilling of certain characters of unstable rock forma-tion, as, for example, the copper-bearing schists of the Miami district in Arizona, is rendered most difficult by what is known as " caving" of the sides of the drill holes. As this caving is very greatly increased by the action of flowing water, it occurred to me, after experiencing a great deal of difficulty with caving in diamond-drill holes which I was drilling for the Miami Copper Co., that if I could substitute air for water, much of the caving-with resultant difficulties, such as decreased speed of sinking and increased consumption. of diamonds-would be overcome. After some experimenting, I found that it was perfectly practicable to substitute air for the water; forcing the air down the hollow rotating rods in the same manner as is done with water, the air passing out around the bit, which is thus cooled, and ascending on the outside of the rods to the collar of the hole, carrying the borings in just as satisfactory a manner as had been done by the water, but without the accompanying destruction or caving of the sides of the drill holes such as had been so generally experienced with the water. When water was encountered in the drilling this water was forced up to the collar just as it would have been had water been used in the .drilling, but with the correspondingly decreased flow there was relatively less washing or caving of the sides of the drill holes. The only change necessary in the arrangement of the drill is that a cross instead of a tee is used at the collar of the hole. A tightly woven jute bag is attached to one arm of the cross, for collecting and filtering the sample; and when drilling in dry ground a jet of water is attached to the opposite arm of the cross, to collect the dust and wash down the sample into the bag. The rods rotate through a stuffing box attached to the upper opening of the cross. The distention of the jute bag by the issuing air indicates the operating conditions as sufficiently as did the flow of water when using water in the drill hole.

Jan 10, 1913

By T. B. Brooks

THE iron ores of the Marquette region are mostly extracted in open excavations ; hence the process is more properly quarrying. Several attempts at underground work have been made, which have not, on the whole, been successful. The Edwards mine has been almost entirely wrought by candle-light. The slate ore pit, No. 1, of the New England mine, is now worked in the same way, as is also the Pioneer furnace pit of the Jackson mine. The Champion mine was opened systematically for underground work, with two levels, 60 feet apart, and three shafts at distances apart along the bed. of 200 feet; but this idea has been practically abandoned, the greater part of the ore in that mine being now taken out in open pits. Several other mines have occasionally worked underground stopes, but only temporarily; if such stopes could not be opened out to day-light, they have usually been abandoned. In brief, it may be said that no considerable amount of ore has as yet (1870).been extracted underground in the region, and of that so mined very little has been taken out at a profit; and I may add that it seems to be the belief of the most experienced mining men that this state of things will hold for some time to come for reasons which will appear. Nearly the same remarks may be applied to the mines of the Iron Mountain region, Missouri, the ores of which are very similar in character to those of Marquette. Some of the New York and New Jersey magnetic deposits are wrought open, but this is the exception, underground mining there being the rule. The following brief sketch of the geological structure of the Marquette deposits will indicate some advantages of the method of mining employed. The iron-bearing (Huronian) series of rocks, are stratified beds, the principal ore formation being overlaid by a quartzite, and underlaid by a diorite, or greenstone. This ore formation is made up, first, of pure ore ; second, of a mixed ore" (i. e., banded * A second part of this paper was read before the American Society of Civil Engineers. Both papers are embraced in Chapter IX, Part I, Vol. II, Geological Survey of Michigan.

Jan 1, 1873

By William Ives

My presentation is from the viewpoint of the industrial mineral geologist, which is a relatively rare breed. Very few geologists become involved with industrial minerals for two reasons, I think: (1) Much of the industry utilizing non-metallic minerals has developed without the use of geologists in the begin¬ning and many of the management people, who generally derive from the processing plant supervision, tend to take raw materials for granted; and (2) non-metallic minerals are a very insignificant part of the curriculum of virtually all colleges granting a geology degree. One learns about the geology of industrial minerals by working with it. This "on-the-job-training" is probably best because it brings the geologist into close quarters with the production people and the production process. And the industrial minerals field has a distinctiveness when compared with the petroleum or metal mining field in that each deposit can yield a material differing in some aspect from that in any other or within the same deposit. The petroleum from a well in a given field will be similar to that from any other well, but a limestone on one side of a hill can differ signifi¬cantly in elemental composition, calcinability, soundness, specific gravity, or some other factor from the same ledge on the other side of the hill. This characteristic of almost certain variability creates problems sooner or later and provides for much of the employment of industrial mineral geologists. My job seen from the viewpoint of management is "Find us some rock we can extract and process at a profit." The industrial non-metallic geologist has much the same problems and approach as a detective. I do not mean the TV variety with the big mouths and the unfailing knack of spotting the wanted criminal immediately in a city of ten million people. Any real detective will tell you it takes leg-work, knowhow, and persistence to make a case. The same is true for the geologist who finds rock which can be quarried at a profit. I am responsible for finding raw materials for a company which manufactures portland cement and

Jan 1, 1977

Discussion of the paper of Reno H. Sales, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 1524 to 1626. L. C. GRATON, Cambridge, Mass.:-It has been my privilege to read with some care Mr. Sales's paper, and I feel it a sense of duty and a pleasure to discuss it briefly. After two months spent underground in the Butte mines by my associates-Messrs. Augustus Locke, A. M. Bateman, and E. H. Perry-and myself, it seems only fair to record our appreciation of the almost baffling structural complexity of the Butte veins, of the remarkable accuracy with which their mechanical details have been worked out, and of the unusually effective and intelligent use of geologic conceptions in interpreting their subtler characters and significance. During this period, under the courteous and helpful guidance of either Mr. Sales, the members of his staff, or the geologists of other companies, we have been afforded opportunity to test many of the conclusions embodied in the present paper, and it is but just to state that as our observations have accumulated sufficiently the great majority of these conclusions have received unquestioned confirmation in our minds. The pleasure consists in realization that the science of mining geology, to which so many of us have devoted ourselves, actually embraces the possibilities that this paper exhibits. The science of geology has been favored by many brilliant contributions of general nature, and by a smaller number of studies remarkable because of their detail and precision. I know, however, of no other piece of work like this, which, including Mr. Winchell's administration, virtually represents the combined results of over 15 years of work by a staff of trained geologists in a district which measures not much more from end to end than it now does from top to bottom. That this concentration of effort and observation has been required, and that it has been repaid by the results attained, are plentifully evident in Mr. Sales's paper. If one were inclined to doubt this after perusal of the text, surely he would be convinced by the maps and sections, several of which, I venture to say, are unapproached in detail and accuracy by anything attempted before.

Jan 11, 1913

By W. H. Adams

I doubt if many of our engineers know of the existence of coalfields extending over hundreds of miles of territory bordering on and lying contiguous to the Rio Grande River in Mexico. Essential as these facts are to those contemplating the starting of industrial works along our frontier, 1 have not been able to learn that any surveys or examinations have been made of these deposits, arid I trust the preliminary and unofficial investigations lately made by myself may be found of interest, especially to those of our members whose experience has been with poor fuel, or in districts remote from railway facilities. While it is true that Northern Mexico is generally bare of charcoal-making timber, yet no greater mistake can be made than to condemn the light, quick-growing woods found in profusion, and which cannot be excelled in flame or heat-pruducing qualities for boilers, reverberatory furnaces, or hearths. No country could be surer of a full supply of wood if wise legislation in regard to irrigation and preservation of young timber were adopted and enforced, but the beneficiation of the low-grade ores of Mexico demands a more dense fuel for furnace work, and, fortunately for metallurgists, who will hereafter make this frontier a base of operations, there have been disclosed, near the surface, seemingly inexhaustible beds of semi-anthracite and bituminous coals. No extensive openings have as yet been made, and my own workings at the Cedral mines are all that can yet be said to prove the quantity and quality of the coal, other openings furnishing only corroborative evidence. Our location (one hundred and ten miles west of the Rio Grande River) is on the western line of the depository basin, as it has existed since the period of activity along the volcanic line. The region farther inland I have not examined, but the elevations, as a rule, are much greater, though from the nature of the formation, they are not necessarily barren ground. Beginning at the base of the Santa Rosa Mountains (location of the Cedral mines), we find very interesting breaks in the foot-hills, disclosing the stratified rocks from the volcanic centres to the valleys.

Jan 1, 1882

By L Dzinza, K C. Corin, M Tadie

The recycling of process water comes with increased electrolyte concentrations that affect water quality, which may in turn affect the flotation performance of valuable minerals (Hirajima et al, 2016). Electrolytes such as Ca2+, SO4 2- , Mg2+ and S2O3 2- have been surmised to have an impact on the action of flotation reagents such as collectors (Ikumapayi et al, 2012). Xanthate collectors are known to play a significant role in imparting hydrophobicity on mineral surfaces to enhance their flotation. The interaction between minerals and xanthates is well known to be electrochemical in nature. Such redox processes may be elucidated by electrochemical techniques. Since the mechanisms involving the interactions between electrolytes in process water with sulfide minerals and the subsequent adsorption kinetics of collectors are not well understood, this study therefore aims to provide fundamental knowledge to unpack the mechanisms involved when electrolytes interact with Platinum Group Minerals (PGMs) and how these interactions may affect xanthate adsorption. The interaction of sodium iso-butyl xanthate (SIBX) in the presence of electrolytes at increasing ionic strength was investigated by rest potential measurements, to explain the impact of electrolytes on the adsorption of SIBX on PGMs in the flotation process. Rest potential measurements for PdTe2 and PdS were conducted in an air saturated 0.05 M di-sodium tetraborate decahydrate solution, in the absence and presence of SIBX and electrolytes. It was found that the existence of sulfide and telluride on palladium affects the mechanisms in which electrolytes interact with Pd mineral surfaces. An increase in the ionic strength of Na2S2O3, CaCl2 and MgCl2, increased the interaction between the salts and PdS, thus decreasing the extent to which SIBX interacted with PdS. An increase in ionic strength for Na2S2O3 increased the interaction between Na2S2O3 and PdTe2 and therefore decreased the extent to which SIBX interacted with PdTe2. Other salts investigated in this study increased the rate of oxidation of PdTe2 with an increase in ionic strength thereby enhancing the interaction of SIBX and PdTe2. This study has shown that mineral type, electrolyte type and concentration all have an impact on the mechanisms that result in the adsorption of SIBX on PGMs.

Aug 24, 2022

By F. Soumis

This paper describes an integrated procedure for the very short term production planning of an open pit and the execution of this plan: the truck dispatching. Integration of plan and dispatch means that the plan is realistic so that its objectives can be realized by the dispatch. This realism is obtained by supplying the plan optimization, which involves mixed integer programming, linear programming and non-linear programming, with experimental O.R. models of waiting and blending. The arrangement of these models in the computer programm has made it possible to obtain very short computing time for the planning in spite of the width of the optimisation. The dispatching of a truck is made by solving a classical assignment problem for each dispatch over a horizon of the expected*next 10-15 trucks to request dispatches. This deep-reaching dispatch procedure uses the continuously arriving information about trucks' positions and shovels situations and models by probability functions the expected waiting time of shovels and trucks. In this manner trucks and shovels are synchronized and last moments' opportunities for productivity gains can be obtained. The dispatch procedure takes .5 second on PDP11. This integrated planning and dispatch procedure gives high productivity while ensuring good blending. Results from the Mount Wright mine of the Quebec-Cartier Mining Co., where the integrated procedure has been installed on the existing computer equipment PDP11, are included.

Jan 1, 1989

By J. Masinja

The mining industry is known to be a potential major contributor to the industrial development of any economy. Large-scale mining has been going on in Zambia for the last 100 years. The impact of mining in Zambia has been to create a development corridor along the line of rail to the Copperbelt Province, where hitherto, mining was concentrated, and then to develop a large consolidated high-density economic zone covering an area of about 72 km by 60km. This area is home to a number of very large integrated copper/cobalt mining complexes. The mining zone has expanded to the Northwestern Province in the last 10 years, where the largest copper mine in Africa now exists, having produced about 300 000 tonnes of copper in 2011. The total output of the Zambian mining industry is now about 820 000 tonnes per annum with projections of reaching 1.5 million by 2015, due to new Greenfield investments expected to come online by then. These new mining industry developments have come on the back of strong and sustained high base metal prices, in the last 10 years or so, due to demand mainly from China and India. This new lease of life has increased the contribution of the sector to the national treasury. The mining industry in Zambia has undergone a very important ownership restructuring with the sale of the previously Government owned parastatal, Zambia Consolidated Copper Mines (ZCCM) which dominated the sector, to allow for private sector participation. The privatization process lasted from about 1995 to about 2002. The recent growth of the mining sector has unfortunately not been matched by an adequate supply of skilled manpower for various reasons. These include: (i) A lack of strong in-house training strategies by the new mine owners (ii) Decrease in industry support to the training institutions (iii) The demise of and restructuring of ZCCM which has consequently limited the Government human resources planning tools for the mining sector (iv) The cyclic nature for the fortunes of the sector has lead to fluctuating interest of student recruitment into training institutions (v) Limitations, both staff and equipment, in the training institutions (vi) A re-structuring of the training institutions This paper examines the current status, and student output from tertiary training institutions for the mining sector in Zambia. This is then compared to the skilled labour demands of the sector. The various cause and effect issues are considered and a proposal on how this skills gap could be addressed sustainably is proposed. Keywords: skills gap, graduate training, quality of graduates

Sep 1, 2012

By V. Maseko, C. Musingwini

"When considered collectively, Mineral Resources and Mineral Reserves are arguably a key asset for any mining company. Mineral Reserves are the economically mineable portions of Mineral Resources. They therefore provide a good indication of the economic prospects in the short to medium term and associated non-financial impairments for mining companies, hence a focus on Mineral Reserves. An assessment of modifying factors for converting Mineral Resources to Mineral Reserves revealed that Mineral Reserves were most sensitive to long-term commodity prices, hence the focus on long-term commodity prices. The justification for selecting gold and platinum mines is that they collectively make a significant contribution to South Africa’s earnings from mining.The introduction of the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (SAMREC Code) in 2000 informed the basis for analysing long-term commodity price assumptions for major South African gold and platinum mining companies between 2000 and 2016. The analysis revealed that the least number of non-financial impairments occurred when long-term commodity prices were within ±5% of spot prices. This finding suggests that this range is the ideal range for long-term commodity price assumptions to improve confidence in Mineral Reserve declarations and minimize impairments. Introduction The South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (SAMREC Code) defines a Mineral Resource as ‘a concentration or occurrence of solid material of economic interest in or on the Earth’s crust in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction’ (SAMREC, 2016, p. 18). Mineral Resources are categorized according to increasing levels of geoscientific confidence or knowledge, from Inferred to Indicated and lastly, Measured categories. The SAMREC Code defines a Mineral Reserve as ‘the economically mineable part of a Measured and/or Indicated Mineral Resource’ (SAMREC, 2016, p. 25). In some of the other reporting codes such as the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code), a Mineral Reserve is synonymous with an Ore Reserve. The conversion of Mineral Resources to Mineral Reserves involves applying modifying factors, which are non-resource considerations. The modifying factors used in the Mineral Reserve estimation process include mining, metallurgical, processing, infrastructure, economic, marketing, legal, environmental, social, and governmental factors. Each of these modifying factors consists of several components which require due consideration in the estimation of Mineral Reserves. Table I shows some of the components typically considered for each of the modifying factors."

Mar 1, 2019