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By H. S. McQueen

The insoluble-residue method for the examination and correlation of limestones and dolomites, or other sedimentary rocks containing calcium and magnesium carbonates, originated and was developed in the laboratory of the Missouri Geological Survey. The numerous and ever-increasing problems in the field of applied geology, and the need for a tool or aid in the solution of them, led to experimental work with samples collected from deep wells, in the early part of 1924. The success attained, almost at the outset, with this method was so great that the method has now been developed from the state of the experimental to the realm of large-scale, every-day routine. In a previous paper the writer1 described the procedure in detail and the characteristics of the residues obtained from certain Paleozoic formations in Missouri. The purpose of the present paper is to discuss the economic application of the insoluble-residue method. Developmental History Within the Ozark region of southern Missouri the geologic column consists of Lower Ordovician (Canadian of Ulrich) and Upper Cambrian formations, which are composed mainly of dolomite with subordinate amounts of sandstone, shale and limestone. Chert is found to some extent in all except one of the dolomite formations. The stratigraphy of the region is complex because the dolomites have lithologic similarities, fossils are few and often poorly preserved, and identifiable horizons within the comparatively thick formations are not common. Although considerable stratigraphic work of an areal nature had been done for a period of many years by the Missouri Geological Survey, the detailed geologic succession had not, until a few years ago, been systematically worked out. The problems of subsurface stratigraphy were even more complex. This region constitutes the main ground-water province of the State of Missouri and within it wells of varying depths are drilled in order to obtain supplies of ground water. In the work of the State Geological Survey in connection with the drilling of water wells for public supplies * Published with the permission of the Director, Missouri Geological Survey and Water Resources. Manuscript received at the office of the Institute Feb. 20, 1936. Assistant State Geologist of Missouri; Missouri Geological Survey, Rolla, Mo. References are at the end of the paper.

Jan 1, 1937

By Mehmet F. Taner

"The East Sullivan Stock (ESS) is a small, composite felsic alkaline pluton of presumedlate Archean age in the Val d’Or mining district. Three main facies have been distinguished: mon-zonite sensu stricto, porphyritic monzonite, and green trachytic porphyry. This monzonitic group ofrocks is of relatively homogeneous composition with high abundances of Na2O, K2O, Ba, Sr, Rb, Zr,Mo and LREE. The alkaline ESS is distinguished from other igneous units in the Val d’Or miningdistrict, such as the Bourlamaque Batholith, by relatively high concentrations of Ba, Sr, Rb, Mo, Cuand Au. The ESS hosts many base (Cu, Mo) and precious (Au) metal occurrences, including: (1)porphyry style Cu-Au-Mo disseminated sulfde deposits, (2) Cu-Au deposits in volcanic rocks near the ESS contact, and (3) pyritic gold mineralization in east-west trending shear zones. The ESS is well defined by concentrical zoning on the aeromagnetic vertical gradient color map, and displays four linear trends, which are assumed to be structural lineaments, at 035°-055°, 320°-300°, east-west, and north-south. The main mineral occurrences related to the stock display a preferred spatial association with the east-west linear magnetic trends.The ESS is preferentially located along a major structure and was emplaced late in the evolutionof the Abitibi subprovince like other felsic alkaline plutons. This stock is similar to late-tectonic min-eralized felsic alkaline intrusions of the Kirkland Lake and Larder Lake mining districts in Ontario, and to the Allard stock in the U.S.A. which is associated with gold and base metal mineralization. Similarities also exist with younger alkaline plutons associated with Cu-Mo-Au porphyry deposits in the Canadian Cordillera, which formed in tensional tectonic environments. The felsic alkaline magmamay have formed by partial melting of deeply buried supracrustal rocks, concomitant with the development of deep fractures such as the Cadillac Fault. In such an environment, hydrothermal solutions carrying remobilized metals from deep supracrustal rocks may have deposited gold and base metals in structural traps. Plutons similar to the ESS should be good targets for mineral exploration. Copyright © 1996 Canadian Institute of Mining, Metallurgy and Petroleum."

Jan 1, 1996

By S. Suphi Yavasca, A. M. Gaudin

THIS paper is intended as a contribution to our knowledge of the mechanism of comminution and of the work of crushing. In a previous paper' it was shown that with quartz comminution proceeds as follows I. The size distribution of broken fragments made by a single fracture is such that the new surface on each grade is the same. 2. Multiple fracturing results in a size distribution such that in the fine sizes the surface per grade is the same in every grade; in coarse sizes the surface per grade decreases gradually with increasing size. In that paper it was mentioned that determinations on minerals other than quartz were in course of completion in order to establish the generality of these observations. In this paper, condensed data2 are presented for galena, pyrite and glass. Galena and pyrite are crystalline material and glass is noncrystalline. Galena has excellent cubic cleavage. Pyrite, although cubical, does not have marked cleavage. Quartz, on which the original determinations were made, does not cleave and although crystalline (hexagonal) breaks conchoidally. Glass breaks much like quartz. It is apparent, therefore, that the minerals selected represent some range in character of the solid without covering all possible types. GLASS Fifteen glass marbles were crushed individually in the pendulum crusher described in the preceding paper,1 then subjected to careful screening for 30 min. Six sized fractions were selected and cleaned in a hot 0.12 N solution of hydrochloric acid, washed with distilled water and dried on a hot plate. This was followed by an examination with a binocular microscope, to remove foreign matters not eliminated in cleaning as well as to eliminate "compacts" of fine particles. These compacts are groups of fine iragments that seem to be mechanically stuck together as a result of localized compacting during the comminution operation. The presence and the abundance of these compacts may be related to the amount and direction of the forces applied in different crushing devices. Since, properly, such compacts should be entirely eliminated in the sizing analyses, it is necessary to remove them to the last before making surface determinations on sized fractions. For example, with a - 28 + 35-mesh glass the surface areas of two samples, one cleaned with acid and under the binocular, the other only washed, were 102 and 172 sq. cm. per gram, respectively. Examination of the samples under an Ultropak microscope showed that washing alone failed to remove the compacts and also that it fails to remove certain fine dusts attached to the particles. Cleaning with acid loosens the fine dusts and

Jan 1, 1945

By S. Suphi Yavasca, A. M. Gaudin

This paper is intended as a contribution to our knowledge of the mechanism of comminution and of the work of crushing. In a previous paper1 it was shown that with quartz comminution proceeds as follows: 1. The size distribution of broken fragments made by a single fracture is such that the new surface on each grade is the same. 2. Multiple fracturing results in a size distribution such that in the he sizes the surface per grade is the same in every grade; in coarse sizes the surface per grade decreases gradually with increasing size. In that paper it was mentioned that determinations on minerals other than quartz were in course of completion in order to establish the generality of these observations. In this paper, condensed data1 are presented for galena, pyrite and glass. Galena and pyrite are crystalline materials and glass is noncrystalline. Galena has excellent cubic cleavage. Pyrite, although cubical, does not have marked cleavage. Quartz, on which the original determinations were made, does not cleave and although crystalline (hexagonal) breaks conchoidally. Glass breaks much like quartz. It is apparent, therefore, that the minerals selected represent some range in character of the solid without covering all possible types. Glass Fifteen glass marbles were crushed individually in the pendulum crusher described in the preceding paper,' then subjected to careful screening for 30 min. Six sized fractions were selected and cleaned in a hot 0.12 N solution of hydrochloric acid, washed with distilled water and dried on a hot plate. This was followed by an examination with a binocular microscope, to remove foreign matters not eliminated in cleaning as well as to eliminate "compacts" of fine particles. These compacts are groups of he irag-ments that seem to be mechanically stuck together as a result of localized compacting during the comminution operation. The presence and the abundance of these compacts may be related to the amount and direction of the forces applied in different crushing devices. Since, properly, such compacts should be entirely eliminated in the sizing analyses, it is necessary to remove them to the last before making surface determinations on sized fractions. For example, with a — 28 + 35-mesh glass the surface areas of two samples, one cleaned with acid and under the binocular, the other only washed, were 102 and 172. cm' per gram, respectively. Examination of the samples under an Ultropak microscope showed that washing alone failed to remove the compacts and also that it fails to remove certain fine dusts attached to the particles. Cleaning with acid loosens the fine dusts and

Jan 1, 1947

By S. Suphi Yavasca, A. M. Gaudin

This paper is intended as a contribution to our knowledge of the mechanism of comminution and of the work of crushing. In a previous paper1 it was shown that with quartz comminution proceeds as follows: 1. The size distribution of broken fragments made by a single fracture is such that the new surface on each grade is the same. 2. Multiple fracturing results in a size distribution such that in the he sizes the surface per grade is the same in every grade; in coarse sizes the surface per grade decreases gradually with increasing size. In that paper it was mentioned that determinations on minerals other than quartz were in course of completion in order to establish the generality of these observations. In this paper, condensed data1 are presented for galena, pyrite and glass. Galena and pyrite are crystalline materials and glass is noncrystalline. Galena has excellent cubic cleavage. Pyrite, although cubical, does not have marked cleavage. Quartz, on which the original determinations were made, does not cleave and although crystalline (hexagonal) breaks conchoidally. Glass breaks much like quartz. It is apparent, therefore, that the minerals selected represent some range in character of the solid without covering all possible types. Glass Fifteen glass marbles were crushed individually in the pendulum crusher described in the preceding paper,' then subjected to careful screening for 30 min. Six sized fractions were selected and cleaned in a hot 0.12 N solution of hydrochloric acid, washed with distilled water and dried on a hot plate. This was followed by an examination with a binocular microscope, to remove foreign matters not eliminated in cleaning as well as to eliminate "compacts" of fine particles. These compacts are groups of he irag-ments that seem to be mechanically stuck together as a result of localized compacting during the comminution operation. The presence and the abundance of these compacts may be related to the amount and direction of the forces applied in different crushing devices. Since, properly, such compacts should be entirely eliminated in the sizing analyses, it is necessary to remove them to the last before making surface determinations on sized fractions. For example, with a — 28 + 35-mesh glass the surface areas of two samples, one cleaned with acid and under the binocular, the other only washed, were 102 and 172. cm' per gram, respectively. Examination of the samples under an Ultropak microscope showed that washing alone failed to remove the compacts and also that it fails to remove certain fine dusts attached to the particles. Cleaning with acid loosens the fine dusts and

Jan 1, 1947

By M A. Gontalves, A F. D C Varajpo, S A. Stachissini

Clays from the Santa Elena Peninsula, south-east of the Ecuador coast, were investigated with a view to identifying their main mineralogical, physical, chemical and textural characteristics as well as their potential for industrial use as adsorbents. Identified as calcic bentonites, two representative samples from the Tosagua Formation (Oligocene to Lower Miocene) were selected for acid activation trials. The selection criterion was based on the greatest amount of clay fraction (<2 ¦m fraction) associated with the greatest content of montmorillonite. For the activation treatments, HCl and H2SO4 solutions of 4, 6 and 8 N were used in a stirred glass reaction vessel with the clay sample under reflux during four hours at temperatures of 70¦C for HCl and 85¦C for H2SO4. Mineralogical analysis by X-ray diffraction (XRD), chemical analysis by X-ray fluorescence (XRF), differential and gravimetric thermal analysis and measures of density, surface area and porosity indicated the changes occurred in the crystal structure of the montmorillonite. The acid treated clays were utilised in trials of purification and decolourisation of soybean vegetable oil in a ratio of 2:100 (clay/oil) at 90¦C for 30 min, under constant stirring. After centrifugation of the suspension, the wavelength of the bleached oil was measured by UV-visible spectrophotometer and the bleaching capacity of the clays was determined. The best bleaching capacity of the samples was obtained with 6 N H2SO4 acid-activated clays. The bleaching capacity was compared to Tonsil, a commercial acid-activated clay and similar results between them evidenced the potential industrial application of the Ecuadorian clays to bleaching of vegetable oil.

Jan 1, 2008

By R. P. Olsen, A. K. Schellinger

Molten silicate salts, the important industrial byproducts termed "slags," are known to be electrolytic conductors at furnace temperatures. This property is due to their partial dissociation into ions with the ion kind and size being closely related to the slag composition. Ionic conductance, in liquids, is a function of the viscosity, which in turn is a function of the temperature. It could be anticipated, therefore, that a semi-log plot of conductivity vs. reciprocal absolute temperature might yield a straight line, in the case of molten silicates and salts. As liquids, the viscosity of these slags should follow the Shepard1 relationship: log viscosity = A/T + B Then, if the resistance of the molten slag is directly proportional to the viscosity: log Rs = A/T + B Resistance measurements of molten halide salts,2 and silicate salts34 by various investigators have, indeed, shown this straight line relationship between resistance and temperature. A further relationship between the conductivity versus the degree of ioni-zation, the size of the ions, and the slag composition is, also, to be expected. Large ions, and fewer ions, would move more slowly in a potential field and could not carry as much current as smaller, more numerous, and mobile, ions. Conductivity, therefore, would be smaller in the presence of such large ions and higher slag viscosities. The conductivity-composition relationship is of considerable interest in the case of the industrial slags produced in iron blast furnaces, and non-ferrous smelting furnaces. These slags usually approximate three component systems with several minor components as impurities. At least one of the major components is commonly purchased for the sole purpose of rendering the slag less viscous at a reasonable furnace temperature. Should the conductivity be related rather directly to the concentration of such a purchased slag component (that is, CaO) instrumental measurement and control at the furnace might be possible. Modern tele-metric control methods in aqueous chemical process industries are often based on the property of conductivity of solutions, and its variation with composition. Investigators3 of the phenomenon of electrical conductivity in molten blast furnace slags have established that these systems show lines of equal conductivity on their ternary diagrams at one temperature level. These isocon-ductivity lines form closed contours on the diagrams, and at times, minimum areas occur at which these contours are essentially closed down to a point. The conductivity reading at such a point, at one temperature , would, of course, locate one on the diagram, and give the slag composition. Research in this field is understandably scanty. The reactive nature of

Jan 1, 1950

By E. T. Peters, L. E. Tanner

In the course of a study concerned with the rnechanical behavior of the intermetallic compound CO3V, both structural observations and anomalous electrical-resistivity behavior indicated the presence of a new high-temperature phase in an alloy with the stoichiometric composition, Co-22.4 wt pet V. The evidence, which is given below, suggests that the new phase is situated between the low-temperature ordered hexagonal phase, k,1, 2and the high-temperature disordered fee solid solution, a,3 within a small range of temperature in the vicinity of 1070°C. Structural studies included X-ray diffraction analysis* and electron-transmission microscopy examination* of stoichiometric composition speci- mens homogenized for 1 hr at 1200oC and either air-cooled or water-quenched. The air-cooled specimens yielded X-ray diffraction evidence of the k phase, while electron microscopy revealed a microstructure of both heavily and moderately faulted regions as shown in Fig. 1. The high density of stacking faults (or fine twins) in region A is reminiscent of hexagonal cobalt following its allotropic transformation.4 Selected-area diffraction from this region revealed distinct superlattice reflections of the ordered hexagonal phase, as well as continuous rel-streaks which were normal to the fault planes in the micrograph. The latter is indicative of extremely small spacings between the faults.' Regions such as ß were found to be only partially transformed to the k phase. Attempts to study the antiphase domain structure by either bright- or dark-field techniques were unsuccessful in these initial studies. This was due to the low intensity of the superlattice reflections arising from the closeness of the cobalt and vanadium scattering factors. Quenching Co3V from above Tc appears to suppress the formation of the k phase. Both X-ray and electron-diffraction results indicated that the disordered phase, a, was partially ordered during severe cooling and that the structure of the ordered phase was of the L12 (Cu3Au) type,6 designated here as a'. As in the case of the hexagonal phase, examination of the domain structure was unsuccessful; however, significant information concerning the morphology of this condition was revealed by the appearance of dislocation arrays. In particular, it

Jan 1, 1965

By Herman D. Mendoza

"The removal of finely dispersed mercury from the effluent of small-scale gold mining operations and the eventual recycling of the recovered mercury was investigated. The conventional method of amalgamation, or “ball milling”, involves the mixing of a substantial amount of mercury with ore to recover free gold during the grinding stage. During grinding, a portion of the mercury is transformed into minute droplets, which readily float and disperse in the effluent. A kilo of gold ore containing 20-30 g Au/t, when ground with 3 g of mercury, yields 0.005 to 0.050 mg/l of mercury in the effluent, exceeding the concentration of 0.002 mg/l allowed by law for surface water.A rapid recovery/ recycling process was introduced using the surface-chemical properties of finely dispersed mercury in aqueous suspension. It was observed that fine droplets of mercury in an aqueous environment readily attached onto a collector having positive surface potentials for pH 3 to 10. An example of a suitable collector is alumina (Al2O3), which has an iso-electric point of pH 9.8. When an effluent, coming from a settling procedure after an amalgamation-grinding stage, was passed through a column-bed packed with alumina fiber, removal and subsequent collection of finely dispersed mercury occurred under acidic conditions, pH 3-6. Recovery was around 99.5%, yielding an acceptable quality of water safe for disposal into the aquatic environment. The collected droplets of mercury, which are left in the column-bed of alumina fiber, were subsequently treated with a cleansing solution at alkaline conditions pH 10 -12. At these conditions, both mercury and alumina fiber carry negative surface potentials, which results in the eventual detachment of attached mercury from the alumina collector. The effective recovery of attached mercury from the alumina collector by the detachment procedure is only 30-35%. The collected mercury from the cleansing stage can be collected, cleaned and can be used for subsequent amalgamation processes. The attachment and detachment behaviour of finely dispersed mercury onto and from the microscopic collector alumina is shown in Figure 1. The result of attachment and detachment were analyzed using existing interaction energy theories like the Darguin-Landau- Verwey- Overbeek (DLVO) Theory."

Jan 1, 2003

By Joseph Fernandez, Luminita Calin

INTRODUCTION The Tunnel and Reservoir Plan (TARP), commonly known as the Deep Tunnel Project, is the daring and unique concept developed by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) as a two-phase solution to the problem of waterway pollution and basement flooding due to sewer system backups created by the combined sewer over-flows (CSOs). Phase I, primarily for pollution control, includes the tunnels, shafts, connecting sewers and structures. These Phase I facilities intercept, during wet weather events, the CSOs within the MWRDGC TARP service area. The tunnels and shafts provide temporary storage of the CSOs for subsequent treatment at Water Reclamation Plants (WRP) before discharging into waterways. Ultimately, upon completion of Phase II, the tunnels, located from 45 m(150 ft) to 100 m (330 ft) below ground, will convey the CSOs to reservoirs for storage until WRP capacity is available. Phase II, which includes the reservoirs, pumping facilities, additional tunnels and shafts, has been planned to serve a dual purpose. The reservoirs provide storage of excess flows during wet weather events, those beyond the WRP capacity. Following the wet weather events, the stored flows can be conveyed, at controlled rates, to the WRPs for full treatment. These excess flows previously would have resulted in both overflows into the waterways and eventually backups in the local sewer systems. The storage capacity of the reservoirs also will promote the full utilization of the conveyance capacity of the tunnels and shafts, which in turn results in optimizing the conveyance capacity of the existing sewer systems. Therefore pollution control is further enhanced by allowing for capture of a greater volume of CSOs and greatly minimizing backups in the local sewer systems. The TARP project consists of four systems: O’Hare, Mainstream, Des Plaines, and Calumet, covering a total area of 971 km2 (375 mi2) and serving the City of Chicago and 51neighboring communities as shown in Figure1. With only two contracts left before completion of the Phase I tunnels, the 12.7km (7.9mi) Torrence Avenue leg, to be awarded in 1997, and the 12.4km (7.7mi) Little Calumet leg unfunded as of yet, both part of the Calumet System, the pollution control phase of the project is now 86% complete (Table 1).

Jan 1, 1997

By Eric Jette

THE results of an investigation of the ternary system iron-chromium-ilicon were reported in 1936 by the present authors.1 Partly for the sake of theoretical interest, and partly because of the possible commercial importance of these alloys, the present investigation was undertaken to determine the effect of some of the commoner elements likely to occur, deliberately or otherwise, in such alloys if made on a commercial scale. The elements thus added were carbon, nickel or manganese. The alloys studied were, therefore, parts of quaternary systems. This investigation was concerned primarily with the effect of these additional elements on .the alpha-iron phase and the boundary between this phase region and the alpha plus sigma two-phase region. The sigma phase is a ternary solid solution based upon the compound FeCr. The work was performed mainly by X-ray methods, but a number of microscopic examinations were also made and are reported. While isolated alloys in the composition ranges studied may have been discussed in metallurgical publications, no systematic investigation of any assistance to us was found. Of the earlier work, the investigations on the iron-chromium-carbon system and on the chromium carbides by Westgren and his coworkers,2,3 enabled us to identify the carbide phase. Several articles appeared after the present experimental work had been completed. Lucas and Wintrup4 determined the solubility of carbon ill molten iron-chromium-silicon alloys. Tofaute and his coworkers5,6 have made detailed studies of the iron-chromium-carbon system, which will he referred to later.

Jan 1, 1937

By B. C. Allen, W. D. Kingery

Surface tension and its temperature dependence have been determined for pure liquid Fe, Cu, Co, Ni, and Sn and for Fe-C, Co-C, and Ni-C alloys. The temperature coefficient of surface tension is negative for all these liquids. The surface tension and wetting behavior of tin and tin-titanium alloys on A120,, Si,N,, MoSi,, and Sic, as well as the behavior of titanium-containing nickel alloys on A1 20, have been determined over a wide temperature range. For all the solids investigated titanium additims markedly lower the contact angle. Some limits for the solid-surface energies have been calculated from liquid surface tension and wetting behavior. SURFACE tension and interface energy are important variables in a number of metallurgical and ceramic phenomena, and have been discussed at some length in connection with determining micro-structure of polyphase systems,' solid-state sintering,' thermal etching of grain boundaries, heats of solution and fine powders,'1 grain-growth phenomena,' the mechanical behavior of fine foils and fibers, nucleation, soldering and brazing,' and other phenomenz of academic or practical interest However, until recently few quantitative data have been available for high-temperature systems. Among available data are some indicating positive temperature coefficients for the surface tension of liquid copper,*,11,'2 cast iron,l3 and iron-carbon14 alloys. Although carbon was found to be not surface active in iron at 1570" some preliminary studies had indicated the possibility of a positive temperature coefficient for the eutectic composition at lower temperatures.16 One part of the present study has been largely concerned with determining the temperature coefficient of surface tension for several metals at elevated temperatures, In addition to surface-tension studies, the wetting behavior of alloys containing titanium has been investigated over a wide temperature range. Previous measurements indicated that titanium was selectively adsorbed from nickel at a liquid nickel-solid alumina interface,17 and the use of titanium hydride or titanium-alloy techniques for metal-ceramic soldering is well known. In the present study, previous data have been extended to new alloy systems, and measurements have been carried out with other oxidation-resistant ceramics. EXPERIMENTAL The sessile-drop method was employed to measure liquid surface tension and contact angle between liquid and solid, utilizing apparatus and techniques which have been described previously.'g The shape of a sessile drop depends on equilibrium between forces of surface tension tending to form a spherical surface of minimum area and forces of gravity tending to flatten the drop. Typical sessile drops are shown in Fig. 1. From precise measurements of maximum drop diameter and drop height the surface tension and drop volume were calculated. Four solid materials were employed as supporting plaques for the liquid-metal drops. Aluminum oxide (99.9 pct, J, T. Baker, reagent grade) was pressed and sintered at 1800°C. Molybdenum-disilicide powder (99.0 pct, Electro Metallurgical Co.) was pressed and sintered at 1650°C. Plaques were cut from silicon carbide (99.4 pct, hot-pressed at Alfred University) and silicon nitride (95.1 pct, with Al, Fe, 0 as major impurities, Norton Co.) rods. All plaques were polished, cleaned, and dried prior to use. A number of metals and alloys were employed. Chemical analyses of vacuum-melted ingots of iron, nickel, cobalt (National Research Corp.), commercial nickel-base alloys, electrolytic copper (International Smelting and Refining Co.), and tin (Mal-linckrodt Chemical Works) are given in Table I. Alloys were prepared in the laboratory by vacuum melting the base metal with either titanium hydride (Metal Hydrides, Xnc.) or spectroscopic-grade carbon (National Carbon Corp.). Nickel-titanium alloys contained between 0.001 and 0.005 pct oxygen and the ferromagnetic metal-carbon alloys contained 0.001 pct. Cylindrical metal specimens (1 to 2.5 g) were machined and bevelled at the bottom to insure a uniform advancing contact angle on melting. Before use the samples were acid-etched, cleaned with acetone, and rinsed in petrol ether.

Jan 1, 1960

RECORDING that the latest annual meeting was the largest and most successful ever held has be-come almost a habit, but when, as this year, the registration on the first day exceeded any other first day by two hundred, the annual dinner attracted nearly 1200, as compared with 750 at the previous largest one, and the number of technical sessions was larger than ever before, there seems no escape from so regarding it. In spite of the third day being a legal holiday (Washington's Birthday) no slackening, in attendance and interest was noted, and throughout the four days the greatest problem was to find enough meeting rooms and chairs to provide for the sessions, of which as many as twelve were in progress at one time. Solution of the problem would not have been possible (since the Engi-neering Societies building, was designed to provide only three general meeting rooms) except that a part of the eighth floor happened to be temporarily vacant. As these extra rooms will not be available next year, it may become necessary to adopt measures to keep the annual meeting down to the limit of facilities for handling it. The meeting opened on Monday with simultaneous sessions on iron and steel, geophysical prospecting, mine ventilation, non-metallic minerals, and milling, methods. The first four, which were continued after the usual recess for lunch, are reported in more detail elsewhere.

Jan 3, 1928

By T. Leser, A. W. Jenike

The problems of caving and underground subsidence can be considered as the failure of a highly compacted rock and its subsequent flow in the form of broken rock. The problem is complex because the propagation of failure and flow have to be considered simultaneously; the yield strength of the virgin rock and the broken rock are different; and, while under certain conditions it is sufficient to consider the virgin rock as homogeneous, the density and the yield function of broken rock are both pressure and time dependent. A study of the failure and flow of solids with a pressure dependent yield function has been published recently by Jenike.' In this paper the density of the broken rock is assumed to be only time dependent and the consequences are examined in the case of one-dimensional vertical subsidence into an initial cavity. The following describes an attempt to develop a tool which, in combination with other tools, may lead to mathematical solutions of real problems of caving and subsidence. STATEMENT OF THE PROBLEM An underground cavity of horizontal cross section 4 = 1 and height 6 is assumed to exist at some depth below the surface. At the time t = 0 rock above the cavity fails and completely fills out the cavity with expanded broken material. With passing time the broken rock consolidates and subsidence proceeds continuously upuard in a vertical shaft. The phenomenon is one-dimensional (see Fig. 1). The problem consists of finding the displacement and the velocity with which the frlmt of the subsidence (wave front) moves upward as a function of the time and of the rock properties. DIFFERENTIAL EQUATIONS CONTROLLING THE PHENOMENON With the assumptions that the broken rock is a continuum and that the subsidence occurs continuously, we can apply the one-dimensional differential equation of contitiuity (conservation of mass) and the equation of preservation of momentum The latter equation is replaced by an assumed relation based on experience, which takes care of the

Jan 1, 1962

By Joseph R. Hatch

Previous studies of the Thompson and Temperly ore bodies show alteration aureoles in the Middle Ordovician host-rock limestones, dolomites and shales extending laterally as much as 60m from the ore. Thickness, texture, carbonate and clay mineralogy, major-, minor-, and trace-element contents; and carbonate carbon and carbonate oxygen Isotope compositions of the host rocks all have been significantly altered by hydrothermal processes. Organic geochemical analyses of samples from the basal 8-cm-thick carbonaceous shale bed and immediately overlying limestone bed of the Quimbys Mill Member of the Platteville Formation, collected from within the ore, the alteration aureole, and the unaltered country rock show: 1) solution of carbonates and residual concentration of organic matter, 2) decreases in the volatile (Si) and pyrolytic (S2) hydrocarbon yields In samples of the basal shale from within the ore, 3) decreases in the relative amounts of the lower molecular weight (<nC25) saturated hydrocarbons in samples from the ore, and 4) no changes in either the organic carbon isotope composition or the Rock-Eval or biomarker thermal maturation Indicators. In light of the 125-170°C depositional temperatures documented for the early marmatitic sphalerltes in these deposits by fluid Inclusion studies, the lack of thermal alteration of the organic matter suggests a relatively short mineralization episode, a conclusion supported by the relatively simple sphalerite band stratigraphy. The decreases in the volatile and pyrolytic hydrocarbon yields for shale samples from the ore supports a model for mineral deposition which obtains sulfide through reaction of brine sulfate and indigenous organic matter.

Jan 1, 2013

By M. L. Fuller

MOST commercial alloys undergo changes in phase composition after casting. This is a natural result of the fact that the alloys are not in a state of phase equilibrium as cast and phase changes will therefore take place, with more or less rapidity, in an attempt to attain equilibrium. The practical aspect of aging in zinc-alloy die castings concerns the changes in physical properties and in dimensions that may accompany aging phase changes. Harmful alterations have been reduced to a minimum and zinc-alloy die castings are being produced today that are so stable with respect to dimensions and physical properties that they are entirely suitable for most practical purposes1. In the first paper&apos; of this series, and in this paper, aging phase changes of zinc alloy die castings have been investigated and the possible influence of these changes on dimensional changes of the castings has been evalu-ated and compared with the dimensional changes actually experienced. The change of dimensions has been selected for practical comparison in these papers because the effect of phase changes on the dimensions of a casting is directly calculable; from X-ray crystal-analysis data of the phase structure. The die-casting alloys considered contain, in addition to zinc, 4 per cent of aluminum, about 0.03 per cent magnesium, and from 0 to 3 per cent of copper. It was shown in the former paper that the eutectoidal decomposition of the beta aluminum-zinc phase, while intrinsically capable of causing a considerable shrinkage, can have very little effect on the observed shrinkage of die castings because it takes place within a few days of aging, whereas the observed shrinkage continues for five weeks. It was therefore concluded that the other existing phase change,

Jan 1, 1936

By John L. Bolles

The mineral processing engineer must have some knowledge of mineral identification, and the greater his knowledge in this field, the greater will be his potential to do his own specialty well. Most metal-bearing ores and industrial minerals require processing of some kind to produce a salable product or a material suitable for further processing. The types of treatment are many, but each one is aimed at separating a mineral or family of minerals from others. Obviously, then, it is basic to all mineral processing to identify the minerals present in the raw material and in intermediate and final products resulting from processing. Very often the mineral processing engineer will enter planning while exploration of a mineral prospect is going on. He will examine hand specimens, drill cores and cuttings, bulk samples, and materials in place. He must identify the valuable minerals, their occurrence and associations with other minerals, and the identity of diluents or host rock. An exact and detailed knowledge of the raw material will usually suggest the treatment processes that should be investigated in the development of the most suitable scheme for that particular raw material in that particular location. Physical properties of a mineral often lead directly to a process for separating that mineral from others. Some well-known examples of these are: magnetic separations for such minerals as magnetite, rutile, ilmenite; gravity separations for gold, silver, galena. cassiterite; flotation separation for most sulfides; distillation of mercury from cinnabar; and selective dissolution in specific solvents such as halite or sylvite in water, gold and silver in cyanide solutions, copper oxides, carbonates, sulfates and silicates in dilute sulfuric acid. These processes and many others are described in detail elsewhere in the Hand¬book and so it is not appropriate to give details here, except to emphasize that processing is aided greatly by complete mineral identi¬fication. Developing a treatment scheme for a new mineral discovery is an exciting assignment fag the mineral processing engineer, but much more of the usual work relates to quality control in existing plants. Here too, mineral identification is important. Some processing is aimed toward producing an end product which will meet exacting specifica¬tions regarding purity or allowable diluents. In this situation it is vital that contaminants be identified so that the process can be adjusted

Jan 1, 1985

In laboratory tests using reconstructed soil columns, rubber latex showed good sealing efficiency when applied at a rate equivalent to 4000-5000 pounds per acre. Results of field testing, however, were inconclusive. The ideal situation in which latex would coagulate in a narrow zone two to three feet below the surface by reacting with acidic or metallic constituents of the soil was not attained. Rather, the latex was deposited progressively as it passed through the soil (most of it remained in the top foot), the rate of deposition being dependent on soil structure and composition as well as on properties of the latex such as particle size and emulsion stability. Latex stability appears to be a more critical property than latex particle size in controlling penetration. Addition of excess anionic or nonionic surfactants to latex improved its penetration into the soil. A styrene-butadiene (SBR) rubber latex of 2400 Å average particle size with high mechanical stability gave the best balance of penetrating ability and sealing capacity in laboratory tests and this was confirmed in tests on a 5 x 5 foot test plot at Lanse, Pennsylvania. This latex was subsequently applied to three one-quarter-acre plots at Lanse by sprinkler irrigation, and compared to adjacent areas that were sprinkled with water only. Soil moisture measurements did not enable us to judge the effectiveness of the seal because differences between sampling positions were greater than differences between treated and untreated sections, but permeability tests showed that water flow was much slower (90-99% reduction) within the top ten inches of soil in the latex- treated sections. This sealing effectiveness was reduced after wintering. There was no deleterious effect on the vegetation as a result of sprinkling the areas with latex. A laboratory study conducted in a 5 x 5 x 5 foot box containing uniform reconstructed soil from a New Jersey source suggests that latex penetration into the soil in the field occurs mainly through natural macro openings and not through the capillaries of the soil structure. Dilute solutions of ammonium hydroxide or sodium carbonate (with no latex present) were found to seal effectively in laboratory soil columns as well as in field applications. However, since these chemicals are water soluble, the seal is temporary. Raw material costs of latex at the application rates used in the field testing are in the order of $1000 per acre. Equipment and operating

Jan 1, 1972

By Robert F. Mehl, Edward L. McCandless

Oriented overgrowths and intergrowths among both metallic and nonmetallic substances have been recognized and studied for well over a century. The work of Widmanstätten in 1808 on the geometrical structure in meteorites, a structure known by his name, demonstrated that oriented intergrowths can occur in purely metallic systems. This fact led to much of the early microscopic study of alloys, contributing greatly to the advance of physical metallurgy. The problem has been attacked again in recent years in a comprehensive fashion, with the object of discovering what atomic movements may occur during phase changes in alloy systems. Much of this work has appeared in the A.I.M.E. Transactions in a series of papers published by Mehl and coworkers beginning in 19311. Although many aspects of this general problem remain unsolved, it may be said that the orientation of a new phase forming by precipitation from solid solution or by transformation invariably bears a unique relationship to the orientation of the phase from which it formed, and that similarity in atomic patterns on atomic planes in the two phases play an important part in determining the orientation relationship. Analogous orientation relationships exist in oriented intergrowths in nonmetallic systems—mineral or inorganic. In 1827 Haidinger2 discovered natural intergrowths of hematite and magnetite, and demonstrated that the rough form of the magnetite octahedrons was delineated by small crystals of hematite, of which the basal (00.1) planes lay parallel to the octahedral cleavage planes of the magnetite. The description of this orientation relationship was later completed by von Rath3, who showed that the edge (00.1): (10.1) in hematite lies normal to the [Ill]

Jan 1, 1937

FRED TURRELL GREENE Fred Turrell Greene was born in Brooklyn, N. Y., Nov. 22, 1872. His father, William A. Greene, was born in Providence, R. I., and his mother, Angenora Semlear, was born in Brooklyn, N. Y. Fred&apos;s early school clays were spent in Boston, whence his father moved to Canada in 1882. Attending first the Collegiate Institute in Toronto, .then the High School at Berlin (now Kitchener), Ontario, where he graduated, Fred progressed to the Toronto University and the Michigan College of Mines, at Houghton, where lie graduated in 1897. He secured employment almost immediately at Butte with the engineering force of the Boston & Montana Consolidated Silver Mining Co., under Chas. S. Batterman. In 1899 he went to Rossland, B. C., where he spent more than a year as mining engineer and assistant superintendent of the War Eagle Consolidated Mining and Development Co. and the Center Star Mining Company Ltd. Returning to Butte in 1900, he acted as assistant geologist for the Anaconda Copper Mining Co. until 1906, when he filled a similar position in St. Paul with the Great Northern Railway for about two years. From 1908 until his tragic death on Christmas day, 1917, his headquarters were in Butte, where he enjoyed an excellent reputation -as consulting mining engineer, with a rapidly widening circle of clients. During the past four years he had been consulting engineer for the Elm Orlu and other mines controlled by Hon. W. A. Clark, and was in charge of underground developments and law-suit preparations for the celebrated apex case between the Elm Orlu and the Butte & Superior companies. At the time of his death he was in charge of similar work for the Utah Metals Co., in connection with their mines at Bingham, Utah. He was also for some years active in the Coeur d&apos;Alenes, as consulting geologist for the Federal and other companies there, and was considered an authority on this as well as the Butte district. Mr. Greene was unmarried, and is survived by his parents, a younger brother, who is in the army, and one sister, Mrs. James A. Hatch, of New York. Some of the most important and valuable ideas regarding the nature and origin of copper ores have originated in Butte, since that district is not only one of the greatest examples of mineralization known in any land, but has gone through a long course of mining litigation, and was, one of the first to be studied intensively by geologists. In connection with the early investigations, as well as with the most recent in that camp, Mr. Greene played an important part. His conscientious devotion to his duties and his intelligent handling of the problems presented for solution sufficiently explain the esteem in which he was held by his employers and his professional associates.

Jan 5, 1918