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By W. C. Ellis, E. S. Greiner

Metallic titanium has been prepared in small quantities since the beginning of the century. Hunter1 reported in 1910 that he obtained a malleable product of 99.9 pct purity by the reduction of the tetrachloride by sodium in a closed container. Later Van Arke12 and Fast prepared small quantities of malleable titanium by thermal decomposition of titanium iodide. Another method for producing malleable titanium from tetrachloride was reported by Kr0ll4 who used magnesium as the reducing agent. More recently Dean, Long, Wartman, and Anderson5 working at the U.S. Bureau of Mines have reported the preparation of the metal on a pilot plant scale by the reduction of titanium tetrachloride by magnesium in an atmosphere of helium. Their product, which is malleable, was used in the present investigation. Early in 1948 after the work of this paper was completed Campbell, Jaffee, Blocher, Gurland, and Gonser6 described the strength and working characteristics of pure titanium which was prepared by the iodide method on a scale producing 300 to 600 g per run, in the form of 0.3- to 0.4-in. diam rods. Their product is characterized by low hardness and large capacity for cold work which they attribute to a high degree of purity with respect to oxygen, nitrogen, and carbon. Titanium has a melting point of about 1725 C," it may be classed as a light metal since the specific gravity is 4.5 g per cc-I. The crystal structure is close-packed hexagonal from room temperature to 885°C. Above this temperature the structure is reported7 as body-centered cubic. The change in crystal structure has been associated with discontinuities in specific heat,8 electric resistanceg and theimoelec-tric force10 at temperatures near 890°C. It is reportedll that annealed titanium has a tensile strength of 78,700 psi which can be increased by cold-work to 123,000 psi. In the present investigation, the lattice constants at room temperature, the thermal expansivity between 30 and 800°C, as well as the electrical resistivity and thermoelectric force against platinum between — zoo and I000 C have been determined. Materials For the measurements, two series of specimens were prepared from titanium furnished by the U. S. Bureau of Mines. The first was made from an annealed sintered compact, 0.38 in. thick. Sections of the compact were cold-swaged with intermediate anneals in vacuum to the sizes used. Sizes over 0.25-in. diam were annealed at I000°C and smaller sizes at 800°C. Specimens originating from the sintered compact are designated in this paper as A. The second series of specimens was made from a rod of titanium, 0.19 in. in diam, which was cold-swaged with the necessary intermediate anneals to the required sizes. This series of specimens is designated B. The impurities in the specimens of titanium, determined by chemical analysis, are given in Table 1. Oxygen and nitrogen which Were not determined by analysis, are probably present although in small quantities in view of the ductility of the material.

Jan 1, 1949

By W. C. Hagel, J. H. Westbrook

THERE has been a recent revival of interest in the intermetallic compound AgMg as an experimental material for study of the physical and chemical properties of simple ordered structures. Studies of mechanical behaviors,1-4 diffusion,5,6 and thermo-dynamic properties7'8 have been reported. In several of these studies, heat treatments have been carried out in argon-filled silica capsules at temperatures as high as 750°C with no apparent adverse effects. The present authors were, therefore, startled to discover in the course of some yet unpublished work, that gross melting of near-stoichio-metric AgMg compositions occurred in such samples more than 100 deg below their melting point of about 800°C. This note is to report a brief series of experiments carried out to establish the reason for this behavior. Gross errors in sample composition and failure of furnace temperature controls were quickly eliminated as causes of melting. The first tangible lead came from chemical analysis of an AgMg sample which had melted during treatment at 750°C. A silicon content of 3.3 wt pct was found. Since satisfactory analyses had been obtained on the original as-cast ingot, contamination by diffusion and/or reaction with the fused silica capsule seemed a distinct possibility. A perplexing fact, however, was the apparently capricious incidence of the effect. Not only was it previously unknown, even in the experience of the present authors; but, in the early part of the present study, melting sometimes occurred and sometimes not with specimens treated under constant conditions. Indeed, one sample successfully survived a 750°C heat treatment and yet melted completely during the course of a subsequent anneal in an identical capsule at a lower temperature. To obtain evidence that silicon contamination could lower the melting point to the extent observed, the following experiment was performed. A series of ternary alloys was made up with a stoichiometric AgMg base and containing 0.1, 0.2, 0.4, 1, 2, and 4 wt pct Si. Melting was done in MgO crucibles under a cover of argon gas. After holding 10 to 20 min in the temperature range 850° to 900°C, the alloys were allowed to solidify in the crucible and the temperature during cooling automatically recorded with a Pt/Pt-10 Rh thermocouple. Results from the cooling curves are shown in Fig. 1. Checks within 2 to 5C° were obtained upon repeated melting, cooling, and freezing. The whole series of cooling curves as well as metallographic examination of the melted alloys established that the AgMg rich portion of the AgMg-Si quasibinary is an eutectic-type system. The melting point of AgMg is lowered from approximately 820°C in the pure stoichiometric binary9 to about 710°C in the saturated intermetallic phase. Since second phase was observed in all samples on cooling to room temperature, the solid solubility of AgMg for silicon evidently falls rapidly with decreasing temperature as indicated schematically by the dashed solvus in Fig. 1. It is thus established that a silicon content

Jan 1, 1963

FOLLOWING the passage of resolutions by a num-ber of the western local sections, which have beer printed in previous issues, the Board of Directors appointed a committee consisting of Messrs. Reynders, DeGolyer, Taylor and Merica, to call on the Director of the Budget, and to bring these resolutions to his attention. In response to a request to the committee Mr. Reynders has addressed the following letter to General Lord. In response to a suggestion made in the course of the conference held between you and President DeGolyer of this Institute at Washington on Oct. 6, I present herewith a brief statement of the reasons that have led the mining engineers and metallurgists of this country to urge upon the Government a policy of increasing support from year to year to the United States Geological Survey and the Bureau of Mines. While these are not the only technical bureaus to which we look for data and guidance in our work of winning and rendering useful the mineral re-sources of the country, they are the ones on which we chiefly rely and the usefulness of which extends over all the industries which are based on mines and mining. In calling this matter to your attention and to that of the departments in which these bureaus are situated, I am acting on behalf of a special committee appointed by the Board of Directors and which includes men in close and intimate contact with the iron, coal, petroleum, metals and metallurgical industries; men well qualified by experience and position to voice the real feeling of these industries. The subject is not a new one to our Board, which has long kept a watchful eye on the work of the two bureaus as would be natural in that the American Institute of Mining Engineers, represents the largest group of technical men and executives and the one of most wide-spread interest in the American mineral industries. With 9000 members and. 27 local chapters scattered among the mining states, the Institute is in a peculiarly favorable position to know and to set out the feeling among mining men and metal-lurgists as to the proper scope of activities of these Federal bureaus, the quality of their work, and the gaps in knowl-edge that most need filling.

Jan 11, 1927

By Eldon C. Pattee

Variations of a very reliable geochemical field test for beryllium developed by Patten and Ward, have been adapted by the U.S. Bureau of Mines to facilitate rapid testing of reconnaissance samples and to aid in rapid examination of known occurrences. Although several qualitative tests for detecting beryllium have been described in the literature,1,2,3, the Patten-Ward4 morin geochemical field method has the advantages of being rapid and being quantitative for minute amounts of beryllium. In addition to the morin field method, Patten, in cooperation with Griffitts, have developed a contact- print method for determining beryllium in hand specimens.5 The semiquantitative method can be used for rapid screening of samples in exploration or reconnaissance work. The use of beads for fusing samples provides a more rapid test, but gives less accurate results than the method developed by Patten and Ward. The semiquantitative method, however, requires less equipment and combines three stock solutions into one reagent for easy application. Estimates of samples in the range from 3 to 1000 ppm varied from about 0.25 to 5 times the actual beryllium content.

Jan 5, 1965

By E. DeGolyer

The problem of good engineering practice and. of good conservation practice in oil production is that of keeping gas in solution. This can best be done by producing a field as a water-drive field. Some degree of water drive is believed to be present in most fields but in the past most fields have been produced too rapidly to allow water drive to be effective. Ultimate recovery should be So per cent greater for fields produced by water drive over that from gas-expansion fields. Wide spacing will permit fields of low-degree water drive to be produced effectively as water-drive fields. INTRODUCTION NEGLECTING all the complicated scientific and technical argument that leads to the conclusion, the solution of the problem of good production practice, of good engineering practice, and of good conservation practice in oil production is to keep gas in solution. This can best be done by producing fields at a rate low enough to make effective the water drive, which exists, it is generally believed, to a degree great enough to be made effective in more than 80 per cent of the fields of the United States. Oil is being so produced in the Ten Section field of California; the Hobbs field of New Mexico; the Yates, Hastings, Friendswood, Anahuac fields and the main sand of the Conroe pool, in Texas; the Magnolia pool in Arkansas, and doubtless in many other pools. The measures of success in the efforts to achieve the solution of the problem are the maintenance of bottom-hole pressure and the prevention of an increase in gas-oil ratio. Some decline from the original bottom-hole pressure and the production of some gas are essential. A pressure gradient from the reservoir to the well is necessary and at least as much gas must be produced as that in solution in a barrel of oil. Once the optimum pressure and the gas-oil ratio have been established, they should be maintained. How common is water drive in oil and gas pools? General opinion is that some degree of water drive is almost universal. Theoretically, this conclusion appears to be a sound one. According to our present understanding of the processes of sedimentation, we would expect to find all sands or sandstone charged with connate water unless it had been displaced by some other fluid, such as fresh water percolating into the beds at the outcrop, or oil and gas, or gas only, in reservoirs. The fact that the original pressure of the fluid system in most reservoirs is approximately that of the hydrostatic head of water for the corresponding depth indicates that the sands are charged with water, and common experience in drilling into the extensions of the porous zones beyond the reservoir is to find them watercharged. The very fact that oil and gas pools have substantial pressures in their original undisturbed state indicates either that a reservoir is a rigid, closed system, a con-

Jan 1, 1941

By Charles Will Wright

THE economy as well as the living standards of a country depends largely upon adequate supplies of raw materials at reasonable prices. Geological and climatic conditions responsible for the occurrence of commercial minerals and the growth of raw agricultural and forest products are so varied in different parts of the world that no country can be self-sufficient. The world is rapidly shrinking because of improvement in transportation facilities, but populations are steadily increasing and so are the needs for a greater production of raw materials and for their more equitable distribution. Too many barriers between nations prevent free access to the main sources of supply of the raw materials vital to neighboring nations and it is just such barriers that are often the cause of friction and even war. The International Trade Organization is doing a commendable job in helping to. break down barriers and to reduce friction, and we should now find ways to facilitate access to these sources of supply and encourage more efficient and greater production of the raw materials so urgently needed throughout the world. This cannot be done by individual selfish governmental agencies, influenced as they are by politics, nor by socialistic governments attempting to nationalize industries. It can be done efficiently only by the free individual through private enterprise properly protected against adverse governmental action. This protection can be supplied by the World Bank.

Jan 1, 1948

By J. H. Palm

Experiments have shown12 that the formula -S = St - (St - Se')e ne [1] expresses very well the relation between the true stress S and the true form monotonic deformation of plastic metals in single tension and compression (Fig 1). St (asymptotic or final stress), Se' (threshold stress) and ne (characteristic or specific strain) are constants, the significance of which immediately follows from Fig 1. Only at the initial stages of deformation the experimental curve runs below the theoretical curve. This may be due, at least partly, to the uneven stress distribution caused by the anisotropy of the crystals. It is now obvious that a similar formula H = Ht- (Ht- He)e ne' [2] might be valid for the relation between the hardness and the strain. The hardness can be only a function of the strain and must therefore be independent on the hydrostatic tension present in the neck during straining. Hence, if Eq 2 is correct it will also represent the relation between hardness and strain in the middle section of the neck, the strain of which is generally assumed to be almost or fully homogeneous. For aluminum, copper, and several copper alloys it is indeed observed that Eq 2 agrees very well with the experimental Vickers hardness-strain relation from zero strain on up to the strain at fracture. Moreover nc' is, for several metals fairly equal to nc- Hence H = C1 + C2S [3] C1 and C2 are constants during uniform uniaxial tension. Eq 3 was also obtained for copper by Voce.3 According to Hencky's theory4 the ratio of the Brinell or Vickers hardness and the yieldstress (expressed in kg per mm2) of a non-strainhardening metal is approximately equal to 2.8. If Eq 1, 2 and 3 are correct the ratio Ht/S, must accordingly be the same for all plastic metals and be equal to 2.8. It is now experimentally established that this ratio varies between 2.7 and 3.1 with a mean value of 2.9. Taking into account that Ht and especially St can be obtained only by extrapolation from the range of rather low strains, the agreement with the theory is very satisfactory. References 1. J. H. Palm: Appl. Sci. Res. Al (1948) 198. 2. E. Voce: Jnl. Inst. of Met. (1948) 74, II, 537. 3. E. Voce: Metal Treatment (1948) 15, 53. 4. H. Hencky: Zlsch. f. angew. Math. and Mech. (1923) 3, 241.

Jan 1, 1950

By Henry Howe

(New York Meeting, October, 1913.) The Equilibrium. Position of A 1.-Some of the most important data on this subject are collected in Table I. Definition of Ae 1-Just as we call A 1 of rising temperature Ac 1, and that of falling temperature Ar 1, so we may give the symbol Ae 1 to the equilibrium position of A 1. Preliminary Assumptions.-In deciding what weight to assign the various data, and indeed what data are to count, three assumptions should be made. These are: 1. The corollary from the phase rule, that the temperature of Ae 1 is constant and independent of the carbon content, though, of course, it may be changed by the presence of other elements. 2. That because neither in heating nor in cooling can the transformation begin before the temperature reaches Ae 1, though it may be delayed by lag till after the temperature has passed beyond Ae 1, therefore Ae 1 should be at or below the observed beginning of Ac 1 and at or above the observed beginning of Ar 1, and, a fortiori, it should be at or below the observed maximum of Ac 1, and at or above the observed maximum of Ar 1. It may be necessary to take these maxima into consideration in view of the experimental difficulty of detecting these beginnings.

Jan 6, 1913

By Sidney Wise

WHILE the installation of mine bulkheads to retain water under high pressure is y no means a rarity, the following points Which arose in the designing and placing of two of these bulkheads may be of interest: The Hibernia magnetite mine, located about 40 miles west of New York, in the State-of New Jersey, is partly filled with water. This mine is located on an ore lens, the outcrop of which is over a mile long. The ore has been mined from this lens from the surface to a depth of more than 1,500 ft. It was held desirable to- separate the old workings from the new, and to allow the former to fill to the 850-ft. level. Two weak places existed between the new and old workings below this level: namely, a temporary bulkhead on the 10th level and a rock bulkhead of indeterminate thickness on the 16th level. When the matter of allowing the old workings to fill was investigated, the fact was developed that if these old workings were filled, the bulkhead on the 10th level would be subjected to a water pressure of about 50 lb. per square inch, and that 200 lb. per square inch would act on the 16th-level bulkhead. As the above-mentioned barriers were not deemed of sufficient strength to permit of these pressures, it became necessary to design and install new bulkheads. Design As the 16th-level bulkhead was required to withstand a pressure of 200 lb. per square inch, it presented some difficulties. A careful consideration of the various types of mine dams now in use led to the adoption of a design of the form of a truncated wedge. In this, the pressure side of the dam is of greater area than the back, so that the resultant action is similar to driving the wedge. By cutting generous skewbacks in the walls, roof, and floor, this type in reality becomes an invisible arch. The wedge feature tends to compress the materials in the bulkhead, thereby adding to its imperviousness.

Jan 8, 1914

By Sidney L. Wise, Walter Strache

While the installation of mine bulkheads to retain water under high pressure is by no means a rarity, the following points which arose in the designing and placing of two of these bulkheads may be of interest: The Hibernia magnetite mine, located about 40 miles west of New York, in the State of New Jersey, is partly fillcd with water. This mine is located on an ore lens, the outcrop of which is over a mile long. The ore has been mined from this lens from the surface to a depth of more than 1,500 ft. It was held desirable to separate the old workings from the new, and to allow the former to fill to the 850-ft. level. Two weak places existed between the new and old workings below this Ievel: namely, a temporary bulkhead on the 10th level and a rock bulkhead of indeterminate thickness on the 16th level. When the matter of allowing the old workings to fill was investigated, the fact was developed that if these old workings were filled, the bulkhead on the 10th level would be subjected to a water pressure of about 50 lb. per square inch, and that 200 lb. per square inch would act on the 16th-level bulkhead. As the above-mentioned barriers were not deemed of sufficient strength to permit of these pressures, it became necessary to design and install new bulkheads. Design As the 16th-level bulkhead was required to withstand a pressure of 200 lb. per square inch, it presented some difficulties. A careful consideration of the various types of mine dams now in use led to the adoption of a design of the form of a truncated wedge. In this, the pressure side of the dam is of greater area than the hack, so that the resultant action is similar to driving the wedge. By cutting generous skewbacks in the walls, roof, and floor, this type in reality becomes an invisible arch. The wedge feature tends to compress the materials in the bulkhead, thereby adding to its imperviousness.

Jan 1, 1915

By Wayne S. Cavender

During the past year, geochemical prospecting appears to have come of age as an exploration method, and its acceptance by the mining industry is widespread. There is a growing recognition that applied geochemistry is a scientific tool and must be performed and interpreted by scientific personnel who are trained in its utilization. At present, most personnel training is done by geochemical departments in government organizations and industry groups. Most schools in the United States and Canada do not offer geochemical training, particularly at graduate levels, due to faculty limitations, lack of budgetary support and the erroneous impression that applied geochemistry is not sufficiently academic. As a result, some companies have found it expedient to send selected personnel to European schools for advanced training. A critical personnel shortage now exists will probably continue into the near future. Indications are that the rate of development of new geochemical techniques has levelled off, and the probability of new breakthroughs is not high. Present research is essentially limited to efforts by government agencies and a few private companies. Progress has been the most rapid in the development of analytical techniques, but the need remains for investigation into sampling technology and the development of more quantitative methods for the interpretation of geochemical results. Geochemists need a better understanding of the numerous physical and chemical factors which affect and control primary and secondary dispersion phenomena in all geologic environments. Detailed studies must be made of the relationship between geologic, geochemical and geophysical factors. With better interpretive techniques, the return on the geochemical exploration dollar will increase.

Jan 2, 1968

PURPOSE OF UPDATED ESTIMATE FOR MINERAL INVENTORY BLOCKS During the production stage of an open pit porphyry copper mine it was observed that the expected production grade, as determined from the block inventory estimates, often differed greatly from the head grade of ore delivered to the mill. It was determined that, for purposes of production scheduling and monthly forecasting, better in situ grade estimates for mining blocks were necessary. Because all of the bench blastholes were being sampled, and periodic holes were being drilled into the next underlying bench, much more sample data existed than was being used for estimating the grade of nearby mining blocks. It was reasoned that, by periodically updating the mineral inventory block file over the benches scheduled for mining in the next time period using all existing data, better estimates and forecasts for production grade could be made. BLASTHOLE SAMPLE DATA MANAGEMENT The collars of all blastholes in each mined bench were surveyed and assays run on the cuttings representing the full 12-m (40-ft) bench height. The blastholes range from about 5 to 6 m (16 to 19 ft) apart along the front of the bench as well as perpendicular to the front. Overbreakage often left larger spacings between successive blasts. Fig. 17-1 is a plan map of blastholes on a typical mine bench. All blasthole data were keypunched to a format resembling that of the 12-m (40-ft) composite assay data file as follows: [Collar Coordinates Compite Assoy Hole ID Northing East Elewotion Total Copper Oxide Copper] Because of the many blasthole samples available, and in order not to use excessive computer time for running kriged estimates for 30.5 X 30.5 X 12-m (100 X 100 X 40 ft) blocks adjacent to and beneath the mined area, the decision was made to average all the blastholes falling with each 15.2 X 15.2-m (50 X 50-ft) mined block, and use the mean value of the samples as a regionalized variable for purposes of assigning kriged estimates and estimation variance to adjacent unmined blocks. In other words, instead of using individual blasthole samples for making kriged estimates, the holes were grouped by blocks and assay values were averaged and assigned to the centroid of the holes within the block, which was then treated as a single regional variable for purposes of kriging. See Fig. 17-2. VARIOGRAM COMPUTATIONS AND KRlGlNG RESULTS With the many blasthole samples it was possible to compute directional and vertical experimental variograms for both sulfide and nonsulfide copper assays falling within the enriched mineral zone for the full 12-m (40-ft) sample support. Due to the close spaced drilling, excellent definition of the experimental variograms was possible, and the spherical model exhibited good fits. A three-dimensional kriging program was then run over the two or three mine benches involved in the inventory update, and estimated grades reassigned to all mining blocks falling within the range of the new blasthole assay data according to the anisotropisms of the deposit. Better confidence limits could then be assigned to scheduled mining blocks and better short- range forecasts made. An interactive kriging computer program was also applied for the purpose of determining the kriging variance or estimation of error for larger, irregular mining blocks representing the monthly production from a particular bench. The interactive program permitted the operator to enter the limits of the irregular block onto the screen of a cathode ray tube (CRT) as a series of points around the perimeter of individual gridded blocks making up the larger irregular block. The computer then was programmed to calculate the kriging variance of the larger block using all samples fall- ing within range. Thus the limits of estimated grade could be established at any confidence level. Fig. 17-3 illustrates the output from the interactive kriging program showing the sample points entering into the grade and kriging variance computations, and also the kriging coefficient assigned by the computer to each sample.

Jan 1, 1980

By Willard L. Hunter

Four solvent extraction systems were studied to determine their efficiency jor extraction and separation of tantalum and columbium. Aqueous feed solutions of varying HF-HCl concentrations and metal content were contacted with equal volumes of cyclohexanone, 3-methyl-2-butanone, and 2-pentanone and solutions of varying HF-H2S04 concentrations were contacted with equal volumes of 2-pentanone. One multistage continuous test was made in a polyethylene pulse column using cy clohexanone as the organic phase. In each system studied, columbium and tantalum purities in excess of 95 pct with respect to each other were obtained in single-stage tests at low acidities in the feed solution. Separation factors ranging from 1700 to 2400 were obtained when rising HF-HCl mixtures in the aqueous phase. Best results were obtained when a solution of HF-H2S04 was used as the aqueous phase and 2-pentanone as the organic phase. A separation factor in excess of 6000 was obtained in one stage with aqueous solution concentrations of 2 _N HF and 2N H2S0,. When acid concentrations were increaszd to 52 HF and 10 _N H2S0,, 99.9 pct of the tantalum and 98.2 pct of the columbium initially present in the feed solution were transferred to the organic phase. The separation of columnbium and tantalum obtainable by means of the solvent extraction systems presented in this paper was found to corn -pare favorably with other systems, including the HF-H2SO4-methyl isobutyl ketone system currently used by most producers for the extraction and separation of these metals. TANTALUM and columbium are always found together in minerals of commercial significance, although the proportion of the two metals in ores varies within broad limits. Columbium is estimated to be 13 times more abundant than tantalum. Five methods generally employed for the separat:ion of these metals are: 1) fractional crystallization (the Marignac process),2 2) solvent separation, 3) fractional distillation of their chlorides, 4) ion exchange, and 5) selective reduction. Of these methods, the one currently used by industry to the greatest extent is that of solvent separation. One of the early technical developments in solvent separation of tantalum from columbium was reported by the Bureau of Mines: the HF-HC1-methyl isobutyl ketone system; data were presented for both laboratory and pilot-plant experimentation.3 Of twenty-eight organic solvents tested for their ability to extract tantalum from an HF-HC1 solution of columbium and tantalum, 3-pentanone (diethyl ke-tone), cyclohexanone, 2-pentanone, and 3-methyl-2-butanone were chosen for further study. Data on the HF-HC1-diethyl ketone system has been published4 and data describing the use of cy clohexanone, 2-pentanone, and 3-methyl-2-butanone as the organic phase are included in this report. RAW MATERIAL The source of tantalum and columbium oxides for this study was ('Geomines" tin slag from the Manono Smelter, Cie Geomines, Gelges, S.A., Congo. In order to extract the valuable Ta-Cb content, the slags were carbided, chlorinated, and the sublimate from chlo-rination was hydrolized and washed free of chloride with water. The washed material was air-dried and stored in a stoppered container. Throughout the paper, "feed material" refers to this mixture of hydrated oxides which was employed because of its high solubility in aqueous solutions. Typical analysis of the hydrated oxides is shown in Table I. I) HF-HC1-CYCLOHEXANONE SYSTEM Batch Separation. Effect of Acid Concentration. To determine the effect of varying the acid concentration upon the transfer of tantalum and columbium, a series of tests was made in which approximately 2.5 g of feed material was added to 25 ml solutions of 2, 4, 6, 8, and 10 N HF and 0 through 5 N HC1. Tantalum pentoxide concentration of the solu%ons was approximately 21 g per liter and columbium pentoxide was 14 g per liter. These starting solutions were shaken with equal volumes of cyclohexanone in 100 ml polyethylene bottles for 30 min. The phases were carefully separated in 125 ml glass separatory funnels. The time of contact of the solutions with the separatory funnels was kept at a minimum to reduce silica contamination. The measured phases were separated into 400 ml polyethylene beakers and the metal contents of each were precipitated by addition of an excess of ammonium hydroxide. Precipitate from each phase was filtered on ashless filter paper, ignited at 800" to 1000°C for 45 min, weighed, and analyzed by X-ray fluorescence.5 Data tabulated in Table I1 and illustrated in Fig. 1, show that maximum separation of tantalum from columbium for each HF concentration was obtained with no HCl present. The purest tantalum product was obtained with some HCl present. The highest separation factor was obtained at 2 N HF and

Jan 1, 1970

By H. J. Levinstein, W. H. Robinson

A method of chemically polishing silver for metal-lographic examination has been developed. The samples are prepared by polishing on 0, 2/0, and 3/0 paper. They are then polished on 600 micro-cut paper, followed by a final mechanical polish on a cloth containing 5µ diamond paste. The samples are then chemically polished in a solution of 100 cc of saturated chromic acid and 5 cc of a 5 pct HC1 solution. The chemical polishing is performed by swabbing with a cotton ball saturated with the solution. During the chemical polishing, the sample is rinsed frequently in running water. Polishing in this manner for 5 min is sufficient to remove the strained material from the previous polishing operations. The amount of material removed is approximately 4µ/min. The surface obtained is flat and free of pits. Fig. 1 is an interference micrograph of a silver surface polished by this technique. If the solution employed is of improper HC1 content, an interference color film will form on the sample. This film can be removed either by swabbing with a cotton ball saturated with ortho-

Jan 1, 1962

By D’Arcy A. Shock

In this year's review, the concept of solution mining has been expanded to include total solution as well as the technology of leaching, or partial solution methods. Leaching methods continue to make strides in the processing of metallic minerals, particularly in copper and uranium production. No quantitative data are available on the increase of leach operations; however, it is known that there were more systems installed in 1969 and that the estimated 15% of U.S. domestic production of copper produced in 1968 was by leach methods.1 While the number of publications appearing during the year were few,2,3 there were special sessions in this field at the AIME Annual Meeting and SME Fall Meeting in 1969 and more scheduled for these meetings in 1970. Significant areas that should be mentioned are: the continuing interest in bacteria to convert sulfide sulfur to acid thus reducing reagent costs in both copper and uranium sulfide ores, the exploration of leaching agents other than common mineral acids or alkaline solutions,4,5 kinetic studies of leach mechanisms and the development of microfractures for increased leach solution penetration by use of chemical or atomic explosives.6,7

Jan 1, 1970

By B. H. Bergstrom, A. P. Cohen, D. W. Fuerstenau

B.H. Bergstrorn (Research Div., Allis-Chalmers Mfg. Co., Milwaukee, Wis.) — Fuerstenau and Cohen have concluded from our study of single particle crushing, which had suggested that the size moduli of the crushed specimens were determined by the specific energy expended independent of feed size, that the same independence with respect to feed size exists for the specific energy-product size relationship for rod mills. They present data supporting this conclusion. Our single particle crushing experiments were on single spheres of soda-lime (type of glass was not given in our study) glass for which the feed size can truly be neglected. However, the feed size cannot be neglected in any case where the effective size modulus of the feed is not too much coarser than the size modulus of the product. This can be illustrated in the second experi- ment of Fuerstenau and Cohen where the feed is considered to be the original -6 +%mesh material. However, one can also consider the product from the 7.5-min grind to be the feed for the 10, 15, 20, 25-min grinds, and the 10-min product to be the feed for the 15, 20, 25-min grinds, etc. If the specific energy-product size moduli curves are drawn for these other feeds, as shown on Fig. 3, the new curves (and some curvature is apparent) are much steeper than the -6 +%mesh feed line. The slopes of these new curves are about -1.5, —1.8 and -3.0. This observation is in accord with the observation by Bond, who states that the net specific energy input to a grinding mill is equal to the specific energy represented by the product less the specific energy represented by the feed. Bond presents, on a diagram similar to Fig. 3, a series of curves which illustrate the effect of

Jan 1, 1963

By Theron Wasson

The discovery of two new fields—the Reed City area of Osceola County and the Headquarters field, of Roscommon County —and the important development in Winterfield township, Clare County, again demonstrate the fact that it is the unknown and unexpected that enter very definitely into the oil-producing history of Michigan. This is particularly true in the area of thick glacial drift in the north central part of the state, where the new prolific fields have been discovered this year. This shifts the interest from the southwestern part of the lower peninsula, where a number of pools were rapidly developed during 1939 and 1940, back into the Central Basin area. As a result of strict proration in the new areas, the production for the state of Michigan for the year has not been as great as in 1940 or 1939. In 1941 the total production was 16,300,000 bbl., in 1940 it was 19,551,000 bbl., and in 1939, which was the peak year, it was 23,300,000 bbl. However, the discovery of the new fields this year nearly doubles the estimated reserves for Michigan reported at the end of 1940 In 1941 about 12,000,000 bbl. of oil was produced from the older fields, in which the individual well productions were so small that proration was not an important factor. The total production for the state from the discovery of oil in 1925 through 1941 now stands at 161,205,000 barrels. ActIVe Oil Fields Reed City Field.—In the Reed City field, Lincoln township, Osceola County, only small oil wells were completed during 1939 and 1940. The discovery of much larger production in wells drilled somewhat deeper, by The Pure Oil Co. and the Weber Oil Co., in the early part of 1941, led to the rapid development in this area. Some wells have had initial productions as high as 10,000 bbl. By the end of the year III producing wells were completed, with an average depth of 3600 ft., from the Detroit River formation of Devonian age. The entire development of the field to the end of 1941 was on 20-acre spacing. Headquarters Field.—The Headquarters field, which lies along the line between Clare and Roscommon Counties, was one of the most important discoveries of 1941 and will be the scene of vigorous development during 1942. Production so far has been from the Traverse lime at about 3400 it., and development has indicated that this is probably one of the most productive Traverse pools yet discovered. One well had been given a potential of 10,000 bbl. per day. Dry holes well located in relation to big producers indicate that it is a typical Traverse development. Winterfield Field.-This field, in Winter-field township, Clare County, was discovered late in 1940. By December 1941, 14 Dundee and 5 Traverse producers had been completed. The Dundee lime is found at a depth of 3750 it. and the Traverse lime at 3070 it. Producing conditions in the Dundee seem to be erratic because of varying porosity in the dolomit-ized limestone. Kawkawlin Field.—The Kawkawlin field, which was discovered by the Gulf Refining Co. in 1938, is in Monitor and Kawkawlin townships, Bay County. Small production

Jan 1, 1942

By Theron Wasson

The discovery of two new fields—the Reed City area of Osceola County and the Headquarters field, of Roscommon County —and the important development in Winterfield township, Clare County, again demonstrate the fact that it is the unknown and unexpected that enter very definitely into the oil-producing history of Michigan. This is particularly true in the area of thick glacial drift in the north central part of the state, where the new prolific fields have been discovered this year. This shifts the interest from the southwestern part of the lower peninsula, where a number of pools were rapidly developed during 1939 and 1940, back into the Central Basin area. As a result of strict proration in the new areas, the production for the state of Michigan for the year has not been as great as in 1940 or 1939. In 1941 the total production was 16,300,000 bbl., in 1940 it was 19,551,000 bbl., and in 1939, which was the peak year, it was 23,300,000 bbl. However, the discovery of the new fields this year nearly doubles the estimated reserves for Michigan reported at the end of 1940 In 1941 about 12,000,000 bbl. of oil was produced from the older fields, in which the individual well productions were so small that proration was not an important factor. The total production for the state from the discovery of oil in 1925 through 1941 now stands at 161,205,000 barrels. ActIVe Oil Fields Reed City Field.—In the Reed City field, Lincoln township, Osceola County, only small oil wells were completed during 1939 and 1940. The discovery of much larger production in wells drilled somewhat deeper, by The Pure Oil Co. and the Weber Oil Co., in the early part of 1941, led to the rapid development in this area. Some wells have had initial productions as high as 10,000 bbl. By the end of the year III producing wells were completed, with an average depth of 3600 ft., from the Detroit River formation of Devonian age. The entire development of the field to the end of 1941 was on 20-acre spacing. Headquarters Field.—The Headquarters field, which lies along the line between Clare and Roscommon Counties, was one of the most important discoveries of 1941 and will be the scene of vigorous development during 1942. Production so far has been from the Traverse lime at about 3400 it., and development has indicated that this is probably one of the most productive Traverse pools yet discovered. One well had been given a potential of 10,000 bbl. per day. Dry holes well located in relation to big producers indicate that it is a typical Traverse development. Winterfield Field.-This field, in Winter-field township, Clare County, was discovered late in 1940. By December 1941, 14 Dundee and 5 Traverse producers had been completed. The Dundee lime is found at a depth of 3750 it. and the Traverse lime at 3070 it. Producing conditions in the Dundee seem to be erratic because of varying porosity in the dolomit-ized limestone. Kawkawlin Field.—The Kawkawlin field, which was discovered by the Gulf Refining Co. in 1938, is in Monitor and Kawkawlin townships, Bay County. Small production

Jan 1, 1942

By T. Guilford Smith

In presenting the subject of " Armored Turrets for Coast Defense " to this Institute, I am indebted to the Gruson Ironworks, a company incorporated under the laws of the State of New York, for valuable information, model and plans, by which I hope to make clear the construction and peculiar merits of this class of gun-protection. I wish it understood, however, that this is not an undeveloped and untried inventor's ideal, but an advanced and fully perfected system, which has long since passed the experimental stage and has been adopted by most of the foreign governments, after years of extensive experimenting and the expenditure of millions of dollars. The present seems an appropriate time to present the matter to the scientific public, since, for the first time, it is possible to produce these turrets in this country, of American material, and made by American workmen, owing to an agreement entered into between the Gruson Iron-works and the Fried. Krupp Grusonwerk, of Magdeburg-Buckau, Germany, where they have hitherto alone been manufactured. Although its full development and present perfection have been attained at the German works, it may be of historic interest to state that the first idea of using a rotating protected platform for large guns originated with Mr. Theo. Ruggles Timby, a native of the State of New York, who filed a caveat in 1843 for a " metallic revolving fort, to be used on land or water, and to be revolved by propelling engines located within the same and acting upon suitable mechanism." This was followed in 1862 by the issuance to Mr. Timby of two patents (No. 35,846 and No. 36,593) covering the ideas described in his caveat of 1843. The first practical application of this system was made on the " Monitor," of Civil War fame, Mr. Timby receiving $10,000 for two

Jan 1, 1901

By J. M. Vetter, W. F. Bowman

The Gulf Coast area of Texas and Louisiana produced a total of 47,070,650 bbl. of oil during 1928, a decrease of 7,401,173 bbl. from the previous year. Of this amount Texas produced 39,353,950 bbl., or a decrease of 9,689,296 bbl. from the 1927 output. The Louisiana Gulf Coast produced 7,716,700 bbl., which is an increase of 2,288,123 bbl. over 1927. The decrease in the Texas Coastal area is due principally to the decline at Spindletop. Production at the beginning of the year in this field averaged 53,400 bbl. daily. At the end it had declined to 35,850 bbl. The increase in Louisiana was due to development in new fields at Kelso Bayou (East Hackberry), Sulphur, Sweet Lake, Bayou Boullion and Sorrento. This production was maintained by the drilling of 984 wells. Of this number 736 were located in Texas and 248 in Louisiana. Of the 984 wells drilled, 571 were reported as producers. Distribution of the various completions is listed in the accompanying tables compiled by Oil Weekly. New Developments New developments of particular importance in Texas were the finding of a 5000-bbl. well in formations of Cook Mountain age in the Clay Creek field located in northern Washington County by the Sun Oil Co. ; the discovery of oil at Dewalt in Fort Bend County by the Humble Oil & Refining Co.; the development of commercial production at Raccoon Bend in Austin County by the same company; and the finding of oil in formations of Oligocene age in the Refugio gas field of Refugio County. The most important development in Louisiana was the finding of oil at Sorrento, east of the Mississippi River, by the Gulf Production Co. The importance connected with these finds is not so great in that they opened up new fields, but in the new territories which they open as possibly productive of oil. Eastern Louisiana has been looked upon with considerable doubt on account of the theory which has prevailed among most geologists that the nature of the formations was not such as to produce oil. The actual finding of oil in that area upsets this theory and

Jan 1, 1929