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By John Birkinbine

What is believed to be an Aztec, or possibly a Toltec, mirror, is claimed to have been taken from one of the tombs at Cholula, near the city of Puebla, Mexico, where there is a mound of considerable size, in fact a hill, largely constructed of adobe bricks by the Toltecs, or by those who antedated them. The mirror is formed from a mass of what is evidently pyrite, is nearly a true hemisphere, having a diameter of 3 1/8 inches, and weighs 19 ounces. From its unusual size it is believed to have been hung about the neck of an idol. Other Aztec mirrors of smaller dimensions, and of less weight, so as to be carried about the person, are known; but the one exhibited, being heavy, was apparently intended to be held in the hollow of the hand, in which it fits, and may have been utilized to flash heliotropic signals. The entire surface, both of the base and of the convex portion of the hemisphere proper, has been beautifully polished, but, for some reason, the mirror has been shamefully abused, the edges having been broken, and the center of the base defaced, possibly by some one testing it for precious metals. Near the top of the hemisphere a hole, one-fourth of an inch in

Jan 1, 1895

By John W. Cabot

The fact has long been known, that the temperature at which steel is made and cast bears a very important relation to the molecular condition of the cast ingot. But until quite recently this fact has not received the consideration which its importance seems to justify. That the ingots from a very " hot " blow in the Bessemer converter, for instance, would not roll as well as those made at a lower temperature, was observed very early in the development of the process; but the further investigation of the effects of varying temperature from "hot" to "cold," has not been carried out with that degree of fulness which has been accorded to the effects on the rolling of the chemical elements, and other conditions in the manufacture. In the following pages will be presented the results of an investigation of this subject, undertaken with the view of determining how far the influence of temperature extends, through how great a range its effects can be traced, and what temperature in the making and casting will give the best results in the rolling of the ingots. In the series of observations forming the basis for the conclusions arrived at, while it was not possible to get the full chemical analysis of every heat considered, a complete record of each, in other details, was made, and a large number of these were averaged together to

Jan 1, 1886

By August Wendel

IT is a well-known fact to all Bessemer steel manufacturers using a blooming mill, that ingots show large cracks in the first few passes of the rolls, which, in the following ones, do not always roll up satisfactorily. This deficiency in the quality of the product is generally called " red-shortness," though, in the writer's opinion, mostly unjustly so. Different explanations for the said peculiarity are given by the leading authorities, each works selecting one element as a special scape-goat for the inferior quality of the ingot. The sulphur is generally first charged as being the principal cause of all mischief in this direction ; then, after ascertaining that sulphur is not higher than the average, and sometimes lower in the very worst heats, silicon has to bear its share of abuse. How and why silicon should affect the working qualities of the metal, the writer could never precisely learn, but is convinced that the doctrine of its pernicious influence is an established one with many. In cases where silicon failed to explain everything, resort was taken to calcium, aluminum, and some other known or unknown elements, without settling the difficulty; and lastly, when the skill of the chemist became exhausted, " practical men " came to the same conclusion, which many leading blast-furnace managers had arrived

Jan 1, 1876

By Wilbur Nelson

THE year 1924 showed even less drilling in Kentucky and Tennessee than the preceding year. The operators in this section, however, are anxious to resume development work and are only waiting for a higher market for crude oil before starting such a program. In Kentucky, during 1924, 1605 wells were completed, the combined initial daily production of these wells being 25,599 bbl. Of the total number of wells drilled 1176 were oil wells, 61 gas wells, and 368 were dry holes. The average initial production of the oil wells was 21.8 bbl. per well. In Tennessee, 28 wells having an initial daily production of 1199 bbl. were completed during 1924. Of these, 3 were oil wells, 6 were gas wells, and 19 were dry holes. The initial production of the three oil wells was 400 bbl. Of the total number of wells drilled in Kentucky in 1924, 73 per cent. came in as producing wells; and of those drilled in Tennessee, 10 ½ per cent. came in as producing wells and 20 per cent. as gas wells. In Tennessee, during 1924, wildcatting dropped off considerably and only about one-half as many wells were drilled as in the preceding year; in Kentucky, on the other hand, there was only a slight curtailment in drilling, there being 1943 wells drilled in 1923 as against 1605 in 1924.

Jan 3, 1925

By T. V. Philip, R. E. Lenhart

C. G. Dunn(General Electric Research Laboratory)— It is well recognized that understanding of the formation of the cube-on-edge texture in annealed commercial cold-rolled Si-Fe strip is important industrially as well as scientifically. I would like to make a few remarks on this subject, discuss some points in the present paper, and list two remaining problems that appear to be particularly outstanding. Attention should be drawn to the paper by P. K. Koh,23 which also considers the kinetics of secondary recrystallization in 3 pet Si-Fe, produced commercially by the Allegheny Ludlum Steel Corp. Koh covered a much larger temperature range than do either the present authors or P. N. Richards, whose work is mentioned in a footnote. Koh found an induction period (of short duration) even for isothermal anneals at 1260oC (2300°F). Koh and Dunn24 also found a change in texture during the 1260oC anneal for the same material. On the other hand, the material in coil D, according to Philip and Lenhart, underwent no sec-condary recrystallization, only continuous grain growth. The grade classifications of the four coils studied would suggest, however, that all four materials had developed the cube-on-edge or (110) [001] texture, but to varying degrees. Since no data on this are given and since watt loss depends

Jan 1, 1962

By E. R. Funk, H. Udin, J. Wulff

The surface tension of solid silver is measured by a refinement of the Udin, Shaler, and Wulff technique. The tests were made in a purified helium atmosphere at four different temperatures and various times. The average of the results is y = 1140 + 90 dynes per cm for the range 875° to 932°C. A SUCCESSFUL measurement of the surface tension of solid copper was reported by Udin, Shaler, and Wulff.' They performed experiments on copper held in vacuum within 100°C of the melting point. At these temperatures, the creep rate in 5 and 3 mil copper wires was sufficient to permit determination of a balance between the contractile force of surface tension and the extending force of small copper weights joined to the end of the wire specimens. By suspending a series of variously weighted specimens and measuring the change in a gage length during the test, the balancing applied load could be found. This point of zero strain is a measure of the surface tension. The mathematical formulation of this gives: w = r y [1] where w is the weight for zero strain; r, the radius of the wire; and y, the surface tension. A subsequent note by Udin pointed out that eq 1 applies only to single-crystal specimens. Since the specimens used revealed a "bamboo" structure upon

Jan 1, 1952

By Arthur G. Metcalfe

Arthur G. Metcalfe (SOLAR)—Three explanations to account for mechanical nucleation effects are considered in the paper, viz., theories based on fragmentation, agglomeration, and pressure-wave mechanisms. The authors show that none of these mechanisms will explain the results observed with tin and Sn-Pb alloys. A fourth mechanism of nucleation enhancement was developed during work at Armour Research Foundation on casting of beryllium and, although presented briefly on various occasions, the theory has never been discussed adequately. It is believed that this theory will explain many of the observations. Classical homogeneous nucleation theories assume that embryo nuclei are formed in the melt as a result of compositional and/or thermal fluctuations. Stable nuclei are formed when a critical size is reached such that the decrease in free energy for conversion of this volume of melt to solid offsets the increase of surface, energy. The assumption is made that the average properties of liquid and solid metal can be used. In practice this assumption is invalid and indeed is contrary to the postulation of thermal and compositional fluctuations in the melt. Actually the conditions favoring embryo formation bring the seeds of its own destruction—the thermal and compositional fluctuations leave the embryo surrounded by atoms of higher thermal energies and/or by solute atoms that depress the melting point. Any mechanical method of dispersing this destructive

Jan 1, 1964

By A. W. Hahn

THE importance, to geologists and metallurgists, of knowing the mineralogical forms in which the silver occurs in ores has increased during the past few years, and will continue to increase as long as working hypotheses are converted into proved theories and rule of thumb methods are supplanted by scientific data. The methods used for the determination of these silver minerals have been: (1) careful study of polished ore sections with the microscope, and more recently, (2) metallurgical separation of the ground ore by flotation, tabling and panning, supplemented by microscopic examination of these separated minerals, and chemical analyses. During the course of some experimental work carried on by the testing department of the International Smelting Co. and myself, it becomes important to determine, in a general way, the distribution of the silver values in the minerals, as they exist in Tintic Standard and North Lilly siliceous oxidized lead-silver ores. These mines are in the East Tintic Mining District, State of Utah. In this work the second method was used. Differential flotation tests were run, separating the sulfide from the oxidized minerals, and the products were assayed. Various concentrates were carefully panned and the separated products assayed; special samples of ore were selected and assayed. The microscope was used only for the purpose of determining whether the individual minerals were in the so-called "free" state.

Jan 1, 1929

AN economist at MIT provided Americans with myth destroying information which should prove effective against the gentlemen of the extreme left. For a number of years they have charged that a small number of companies in each industry has been grabbing more and more of the industry's business. M. A. Adelman has shown that the concentration of business in the hands of big corporations has not shown any sign of growth during the last 50 years. Quite the contrary, there has been a slight decline in this concentration, according to Adelman. There are more small companies per thousand population than ever before. Bearing this out is the fact that International Harvester is now doing 41 pct of the possible market against a former 85 pct; American Can Co. has dropped from 90 pct to 50 pct; American Smelting is down to 31 pct compared with 90 pct; and lastly, U. S. Steel which has plummeted from 65 pct to slightly more than 30 pct of the steel market. Declines of the same proportions have hit big companies in other industries. Price cuts on Detroit's 1953 automobiles indicate that even among the biggest competition is still one of the most important household gods. Big business is still slugging it out for the attention of the American consumer. It's a battle which can only have one result-benefit to the man who buys.

Jan 1, 1953

By R. W. Raymond

The important question of the metallurgical value of the coals of the Rocky Mountains and the Pacific Coast is to be settled, of course, by practical experiment. Meanwhile, as I have had occasion to point out, the proximate analyses of these coals throws little light upon it, and is, indeed, likely to mislead the metallurgist, if he compares it with the results of similar analyses upon bituminous and semi-bituminous coals. With the view of showing how large a proportion of the material usually classed as(" volatile matters " consists of combined water, or oxygen and hydrogen presumably in chemical combination, I have collected a number of ultimate analyses from various sources, in the following tables. The numbered analyses in the first table are as follows: No. 1. Monte Diabolo coal—Analyst, H. S. Munroe, Col. School of Mines. 2. Weber Canon, Utah, " " " 3. Echo Canon, " " " " 4. Carbon Stat'n, Wyoming, " " " 5. " " " " " 6. Coos Bay, Oregon, " " " 7. Alaska, " " " 8. " " " " 9. Canon City, Colorado, " Dr. T. M. Drown, Philadelphia. 10. Baker Co., Oregon, " " " 11. Blockcoal,SandCr'k,Ind., " Prof. E. T. Cox. This table affords some suggestive comparisons, to facilitate which a remark or two, explanatory of its construction, will be useful. In the ultimate analysis of coals, the proportions are frequently calculated (as, for instance, in the report for 1872 of Prof. Cox, State

By John W. Bader

Probing a mineralized area with a core drill to find out what's there is fundamentally a simple task, but a costly one. Quite commonly it costs $10, and sometimes more, to extract and assay each foot of drill core obtained. Yet, it is not unusual today to drill hundreds of holes on one mineral property. The initial objective of such probing is almost always simply to determine the potential worth of the ore- body, if any exists, and the question naturally arises: How little sampling is enough for this determination? The mathematics of statistics infer accuracy of estimates largely from the sheer number of samples taken. Mineral exploration usually involves accumulation of large numbers of samples, and thus it is usually not difficult to place narrow confidence limits on either side of the estimated average grade of a sampled orebody. The determination may, or may not, be as accurate as the derivations imply. If it is not, the fault is probably one of misapplication and not with the statistical processes themselves. Un- fortunately, indications are strong that the ordinary statistics of sampling usually cannot be applied to orebody exploration samples with actual attainment of the accuracy of estimate that they express mathematically. For this reason, a more deductive, less mathematical analysis of the sampling may well be worthwhile.

Jan 1, 1970

By Bernard Lallement

INTRODUCTION Geostatistics have been used for five years at the B. R. G. M. to compute the ore reserve estimation. At present this technic is also used at the beginning of the exploration project to determine the best way to prove the orebody. The best way is a compromise between the cost of the exploration and the precision of the estimation. It is clear that geostatistics cannot be used without any data, but very often an exploration project is decided on an orebody which has already been drilled. Old data can therefore be used. This was the case this year for two orebodies: an iron deposit and a lead deposit. The iron deposit was explored by drifts and has now to be proved. We used geostatistics to determine the best drilling pattern. The variograms computed with these old data showed that an anisotropy existed between the two directions of the orebody, which meant that the drill pattern had to be rectangular. The lead deposit was explored by drill holes and a short drift in part of the orebcdy. The problem was to choose between a regular pattern of drill holes or a long drift and some added drill holes. The case of this study will be exposed afterwards. On the other hand, if the orebody is completely unknown, the exploration project generally forecasts two exploration steps (the first step

Jan 1, 1977

By S. Edward Drummond, Charles D. Haynes, Stephen H. Stow

This paper is a preliminary report on the occurrence and distribution of economically interesting heavy minerals (kyanite, sillimanite, staurolite, zircon, monazite, ilmenite, leucoxene, rutile) in sands from the sea floor surface of the offshore area, Alabama-Mississippi. Weight percent of heavies derived from the +60 portion of 97 samples is contoured in [Fig. 1]. Five hundred grains from 42 of the heavy mineral separates were identified and sized microscopically; the data were converted to weight percent for each mineral species and are summarized in [Table 1]. Heavy Mineral Distribution In the Gulf, there is a general westward decrease [(Fig. 1)] in maximum abundance of heavies from 2.4% north of Sand Island at the mouth of Mobile Bay to slightly over 1.0% south of Petit Bois Island and a corresponding decrease in the Mississippi Sound from 1.4%, north of Dauphin Island to slightly over 0.25% north of Horn Island. Average concentrations of heavies for different areas are found in Table 1. There is westerly longshore transport in this area; the interaction of the longshore current with discharge from Mobile Bay and disruptions of the current by Sand Island, possibly aided by a shoaling effect, appear to be the cause of the preferential deposition and concentration of heavies (2.4%) north of Sand Island in 10 to 14 ft of water.

Jan 1, 1977

By Phillip J. Maddex, Ole Skaarup

The quite diverse backgrounds of the authors and their mutual interest in reducing transportation costs has produced some interesting innovations. A few words about their background will tell the reason for this joint paper. . . One is a shipping executive with a background of shipowning, ship management, ship and cargo brokerage and chartering, and most facets of the steamship industry, both American and International. The other is a chemical engineer, thoroughly brought up in the American chemical and mineral industries, with several top managerial positions behind him. They began cooperating when U.S. Borax was contemplating a change in its export shipping program and studying the freight cost for shipping borax from The mines in the Californian desert to Europe, and eastern U. S. markets. In the 20 Mule Team days, borax was exported in 50 pound bags. In 1960 it was still shipped in 50 pound hags. Three main products were shipped: two were anhydrous, and all three were sensitive to impurities. The products were bagged at the plant in the Mohave Desert, and shipped about 150 miles by rail to the port in Los Angeles. From Los Angeles, shipment was made by Conference steamship lines at Conference rates. Anyone who has shipped bagged material to Europe by steamer knows that the tab is anywhere from $20 to $30 or more per ton.

Jan 1, 1970

By August Wendel

It is a well-known fact to all Bessemer steel manufacturers using a blooming mill, that ingots show large cracks in the first few passes of the rolls, which, in the following ones, do not always roll up satisfactorily. This deficiency in the quality of the product is generally called "red-shortness," though, in the writer's opinion, mostly unjustly so. Different explanations for the said peculiarity are given by the leading authorities, each works selecting one element as a special scapegoat for the inferior quality of the ingot. The sulphur is generally first charged as being the principal cause of all mischief in this direction ; then, after ascertaining that sulphur is not higher than the average, and sometimes lower in the very worst heats, silicon has to bear its share of abuse. How and why silicon should affect the working qualities of the metal, the writer could never precisely learn, but is convinced that the doctrine of its pernicious influence is an established one with many. In cases where silicon failed to explain everything, resort was taken to calcium, aluminum, and some other known or unknown elements, without settling the difficulty; and lastly, when the skill of the chemist became exhausted, " practical men " came to the same conclusion, which many leading blast-furnace managers had arrived

By Frederick B. Brien

DEVELOPMENT of uranium extraction techniques over the past ten years has been spectacular. Rapid progress has been made by applying chemical, physical, and engineering fundamentals for the purpose of devising simpler processes, developing continuous procedures, reducing reagent consumption, improving final products, simplifying analytical methods, and treating more refractory ores and ores of lower grade. Since the source of many valuable metals in future will be of necessity from lower grade ores of a complex nature, and since hydrometallurgical processes are often the only means of treating such materials, these recently developed techniques will be of increasing importance. Leaching: A great deal has been published about the important role of ion exchange resins in purifying and concentrating leach solutions. Recent applications indicate that the resins will be very useful in simplifying leaching procedures of ores containing two or more valuable metals.1 The valuable metals may be differentially adsorbed by careful control of the oxidation-reduction potential of the pregnant liquors. For example, treatment of vanadium- uranium ores at present may involve salt roasting, water leaching, acid leaching, carbonate leaching, and intermediate fusions. Use of a single acid leach may now be possible, followed by a two-stage ion exchange technique, comprising initial adsorption of hexavalent uranium and rejection of tetravalent vanadium. The solution is then oxidized, producing pentavalent vanadium, which is later readily adsorbed and stripped into a separate eluate.

Jan 9, 1957

R. S. MACPHERRAN,* Milwaukee, Wis. (written discussion?);-Mr. Stork's paper is very interesting, but I am unable to agree with some of his conclusions. He argues very strongly for the beneficial effect of oxygen, but gives no actual determinations of this element to support -his views. He states that the oxygen resulting from a high bed, heavy charges, low coke ratio, etc. must not be confused with the oxygen under normal conditions. I will be glad to know in what respect these oxygens differ or in what state they occur. Is it his opinion that the beneficial type is present as a dissolved gas and the other as metallic oxide? I will not discuss the first five of his six points, as I have not seen enough trustworthy determinations of oxygen in cast iron to form any conclusions as to its effect. I have never known the addition of manga-nese, however, to reduce the strength of cast iron. Under the sixth point, I would say that the addition of steel lowers the total carbon content, and by this action will increase the strength independently of oxygen. This reduction of carbon operates also to raise the melting point. It is interesting to note here that the author, in order to get proper fluidity for his cylinders, was obliged to reduce his oxygen by raising the manganese in the charge.

Jan 12, 1919

Capital, as represented by mineral resources, is being exhausted rapidly without possibility of identical replacement. The public must be discouraged from thinking-why worry about the bank balance so long as there are plenty of blank checks? Instead of each man, woman, and child being owners of a mineral capital of $89,000 as former Secretary Ickes once stated, they are really the guardians of a mineral reserve which, when harvested, cannot be reproduced. The proper use of this material is the basis of modern civilization and military power. The best American institutions cannot be maintained or transmitted to our children unless this trust is guarded. It is unfortunate that more attention has not been focused on the fact that this country is headed for a have-not status in the family of great nations if some- thing is not done to preserve its mineral heritage. It is the privilege of the United States now to champion and implement democracy because it is industrialized and can get at its raw materials. A high price is being paid every day in mineral depletion for the privilege. No one can eat his cake and have it too. The United States still must face world-wide economic competition and, perhaps, World War III. In the final analysis all wealth comes from the ground, whether plant, animal, or mineral. Value is in-

Jan 1, 1950

By C. G. Dunn, F. W. Daniels, M. J. Bolton

Recent observations on grain boundary movements in sihcon iron have indicated the possibility of studying grain growth phenomena in two-grain specimens in which several variables affecting growth are readily controlled. These variables are (1) the energy per unit area (?) in the grain boundary, (2) the orientation relationship of the two grains, and (3) the radius of curvature (7) of the moving boundary. Ideally, one grain A should be a narrow rectangular parallelepiped adjacent to a second grain ß as shown two dimensionally in Fig 1. Such a two-grain group becomes unstable when one end of grain A is shaped according to the dotted line. Since the width w of grain A remains constant during growth of grain B, T should also remain constant. The other vari- ables mentioned above can be controlled in the preparation of each two-grain specimen.l,2,3 For a parLicular orientation of each grain, is not necessarily fixed; ? may also depend on the orientation of the grain boundary, but this may be controlled to some degree. The energy relationships for the gowth of grain ß may be derived from the more simple arrangement of two grains A' and B' shown schematically in Fig 2. Here B' largely surrounds A'. Assume these grains are oriented with a common plane parallel with the flat

Jan 1, 1950

By Clamer, G. H.

G. H. CLAMER, * PHILADELPHIA, PA.-Unfortunately, prior to the war no serious attention was given to the conservation of tin, notwithstanding that this country is practically dependent upon outside sources for its entire tin supply. Tin is of vital importance in many industries, but it is surprising how many and how excellent are its substitutes when we become acquainted with them. Tin has always been a relatively high-priced metal, and it is part of the human attitude to associate high prices with high standards; it is not until the price of a commodity becomes well-nigh prohibitive that we hunt for substitutes, because the idea of substitution seems always to involve an assumption that the substitute must necessarily be inferior. The history of the development of bearing bronzes is a striking example of this policy. In the early clays, copper-tin alloys were almost universally used, the idea then being prevalent, which is still held by many, that a bearing to resist wear must be hard, and the harder the better. The favorite bronze bearing contained 90 per cent. copper and 10 per cent. tin; frequently, in service which was considered severe, even higher proportions of tin were used.. Such hard alloys have great resistance to compression, but as a rule they had a very wide factor of safety in this

Jan 12, 1918