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By D. Harrington

Although for many years considerable attention has been given to devising safe and efficient methods of using explosives, with some success, relatively little has been done to provide satisfactory storage facilities for them. This was known long before the present war began, but it was emphasized during the past 30 months? inspections of explosive magazines by employees of the Bureau of Mines in administration of the Federal Explosives Act of December 26, 1941. These inspections have revealed woeful in adequacy as well as definite hazards and the urgent need for obtaining better storage facilities either by remodeling old magazines or constructing ink new ones that would afford suitable protection for the contents against theft, fire, deterioration, and detonation. The purpose of this paper is to offer suggestions and to show by sketches and drawings some of the fundamental features of suitable magazines. Type of construction and available materials differ with different; localities, but the information herein contained can be applied to most magazines, whether already constructed or the construct: on of which is planned. It is hoped that this information will be helpful and will aid persons who are trying to provide suitable storage for explosives end detonators. It is also hoped that States and cities will be made aware of the unbelievable laxity practiced in storing explosives in the United States and will take some remedial action.

Jan 1, 1945

By A. U. Seybolt, R. E. Honnemon

THE purpose of this communication is to present activity data of nickel in the Ni-A1 binary system that was obtained for oxidation studies in this system. This data has been calculated from previous aluminum activity data at 1000°C1,2 by two types of Gibbs-Duhem integrations. These results should be of particular current interest to oxidation studies of aluminide coated nickel-base superalloys3 as well as other problems. The aluminum activity of Steiner and Komarek1 is plotted in Fig. 1 as a function of composition in Ni-A1 alloys at 1000°C. The dashed parts of the aluminum curves represent our approximate extrapolations from the directly measured regions. In the terminal solution regions (a and L phases) standard parabolic solution functions of the following form are assumed: where i is the component subscript, Ki is a constant at a fixed temperature, and xi is the atom fraction. The resultant nickel activity curve at 1000° C from the Gibbs-Duhem integration4 of the aluminum data is shown in Fig. 1. The solubility ranges of the phases present in the Ni-A1 binary at 1000°C are also denoted at the bottom of Fig. 1. Corresponding values of the nickel activity, aNi and yNi, are listed in Table I at useful compositional intervals. including phase boundary values. The aNi and yNi data listed in Table I are subject to the uncertainties present in the experimental aluminum activity data1 and to deviations from parabolic solution behavior in the terminal solutions. The errors introduced into aNi and yNi due to the parabolic solution assumption are expected to be relatively small (<20 pct of the values given) in all the phases except the liquid phase. Some deviation from parabolic solution behavior in the liquid phase is indicated

Jan 1, 1970

By William (Bill) H. Walton

"I arrived in Chicago in 1993 with Dr. Ralph Peck’s University of Illinois bulletin titled Engineering Properties of Chicago Subsoils (Bulletin 429), which he published in 1954 with William Reed. Being an outsider, I wanted to learn from Chicago geotechnical practice leaders that included Clyde Baker, Jr., John Gnaedinger, Charles Pfingsten, Dr. Safdar Gill, Robert Lukas and Dr. Jorj Osterberg, who have influenced foundation designs for the structures that make up the contemporary Chicago skyline. One of my immediate goals was to get the Illinois Structural Engineering license to be on par with the likes of Eli Cohen, Mike Tylk, Stan Korista, Bob Halverson, Joe Burns, Ron Johnson, Bill Baker, Bob Sinn, Chuck Anderson and Dave Eckmann, who have led their structural firms in the design of the skeletal core and frames of many of Chicago’s iconic buildings (and for many other buildings around the world). From my time with GEI Consultants (GEI), then on with STS Consultants (STS, and now AECOM), and now back with GEI, I have had the opportunity to analyze and design foundations and, with the help of many skilled foundations and building constructors, to verify that predicted foundation performance matches actual movement data. The theme of Chicago’s foundation design practice is to assume and verify. In 1948, Peck published the History of Building Foundations in Chicago (Bulletin 373) that was updated in 1998 by Baker, Pfingsten and Gnaedinger, who meticulously documented hundreds of Chicago’s foundations, and have shown the value of advanced analyses and testing to advance the deep foundation design practice that includes a variety of high-capacity driven and drilled deep foundations. Mehmet Uyanik, Peck and Baker have made Chicago’s subsurface into a full-scale foundation test laboratory. They confirmed soil mechanics principles like Terzaghi’s 1-D consolidation theory when early foundations bearing on sand-clay crust over soft to medium silty clays (e.g., Auditorium, Masonic Temple, Monadnock Block and Old Board of Trade buildings) took 40 to 60 years to consolidate clay 1 to 2 ft (0.3 to 0.6 m). They also confirmed proven increases in bearing pressures based on measured performance of deep foundations bearing on the glacially derived hardpan clay till and in solid dolomite that underlies Chicago."

Jan 1, 2017

By J. C. Cawley, G. T. Homce, M. R. Yenchek, H. K. Sacks

As in many other industries, such as construction and agriculture, overhead electric power lines are a serious hazard at mining and mining-related operations. Even when excluding injuries that occur during electrical maintenance work, over one fourth of electrical fatalities in the mining industry are due to accidental overhead line contacts, and for each fatality nearly two serious non-fatal injuries occur due to such contacts. In incidents involving high-reaching mobile equipment, many of the victims touched the equipment after the fact, unaware that the machine frame had become energized by the line contact. MSHA data for accidents involving overhead power line contacts in the mining industry between 1980 and 1997 reveal that in 57% of the cases personnel were unaware of the accidental line contact until after one or more workers touched the equipment or a hoisted load and were injured. The situation is similar in the construction industry, where according to the National Institute for Occupational Safety and Health (NIOSH) data at least 20% of such victims are unaware of the line contact. This suggests that a device that alerts workers when a power line has been contacted could help prevent many of these injuries. Such a device would not prevent power line contacts, yet if widely employed could yield a significant reduction in the number of resulting injuries. Researchers at the NIOSH Pittsburgh Research Laboratory are attempting to develop such a device. The approach being investigated is based on measuring electric current flow to ground through a machine during a line contact. The specific technique being tested involves the diversion of some part of this current through a shunt cable mounted on board the machine, to provide a point at which to install a current sensor. Experiments thus far indicate that this approach is feasible. Ongoing research is better defining electric current flow through mobile equipment, refining techniques for measuring this current, and identifying factors that could limit the effectiveness of the proposed alarm.

By Coppock BW

Sintering of lead and zinc concentrates is practised by Sulphide Corporation Pty. Limited to provide both desuiphurised lump sinter feed, for simultaneous reduction to zinc and lead in the Imperial Smelting Process blast furnace, and sulphur dioxide gas for sulphuric acid manufacture. From November, 1969 a 20 percent increase in production rate has been obtained through improvements in operating technique. A gradual increase in bed permeability was achieved by modifications to the feed mix conditioning equipment and by improving moisture control. However advantage could not be taken of the higher permeability to increase sulphur elimination because the hardness of the lump sinter decreased. Higher throughput, better quality sinter and more stable sintering conditions were however made possible by simultaneously: 1. reducing segregation and compaction in the sinter bed, by narrowing the discharge opening of the main layer feed hopper, 2. reducing the sizing of sinter returns to give a closer size spectrum of particles in the feed mix, and 3. increasing the sulphide sulphur content of the feed mix to give higher bed Temperatures.

Jan 1, 1972

By Raymond Dallaire

The Humphrey&apos;s spiral is a static gravity separation device which cannot be adjusted to match short-term variations that occur in the feed. Any disturbance in the feed grade, per cent solids or flow rate affects substantially the recovery and grade of concentrate. Such variations must be minimized in order to maintain the desired rate of production and quality of the product for which the installation has been designed. A study has been performed in which the foregoing assertions were quantified. The feed grade, per cent solids, flow rate and particle size were varied independently. Ore from Carol Lake, Nfld., was used throughout the experiments. This consisted of specular hematite and magnetite in a silica gangue.

Jan 1, 1978

By McQuade CV, Riley SJ

Acid mine drainage is an unavoidable consequence of some coal mining operations. Typically runoff pH is below 3.5 and at these pH levels heavy metals are mobilised. Leachate from coal reject dumps may require collection and treatment to raise the pH and precipitate the metals before being discharged.A bi-product of coal mining operations at Clarence Colliery is coarse washery reject. At present the coarse reject is deposited above ground and rehabilitated. Adjacent to Clarence Colliery is the Kable&apos;s Transport Pty Ltd sand mining operation. It has been proposed that co-disposal of the rejects from both operations may produce a product whose leachate has near neutral pH.

Jan 1, 1998

The Marine Corps has found the Mining and Sapping Department one of the most efficient individual organizations of the Soldiers of the Sea. The men of the unit were assembled among "hard rock" miners from Montana, Idaho, and Utah; most of the detachment hail from Butte. It includes experienced gas-helmet men, blacksmiths, compressors, carpenters, timbermen, concrete and cement gun experts, diamond drill runners, civil and mining engineers, in fact, artisans of every craft in and around mines. Experienced miners with both technical college training in mining and engineering and the practical turn of actual work as mine superintendents and foremen are used as instructors in their craft, except thirty-eight who "shoved off" with the Eleventh Regiment to actually apply their skill in Marine trenches abroad. They are the "finishers" after the trenches are dug. Covering and camouflaging the tops for protection against attacks from the air, engineering the arrangement of the trenches for protection against shell fire, establishing listening posts by projecting "Russian saps" within a few yards of the enemy&apos;s trench; sapping or tunnelling into the very lines of the Teutons, and leaving pleasant little bundles of explosives there; are just a few of the high spots touched by these wizards of the soil. They make the trenches comfortable, plastering the interiors until the underground bunk houses not only look like hotels but are just as comfortable "with all the modern conveniences." Draining is another feature which the work of the Miners and Sappers at least partially assures.

Jan 1, 1919

By B. S. Tani, R. V. Schablaske, M. G. Chasanov

MEASUREMENTS of the solubility of scandium in liquid cadmium from 349" to 606°C by Chasanov, Hunt, Johnson, and eder&apos; led to the isolation and characterization of the intermetallic compound ScCQ. The solid phase found in equilibrium with a saturated solution of scandium in liquid cadmium above 422°C is ScCQ. The equilibrium solid phase below this temperature has not as yet been characterized. Hexagonal needles of ScCG were isolated from a 5 wt pct Sc alloy which had been ice-quenched from 500°C. Free cadmium was leached away from the intermetallic with saturated ammonium nitrate solution. The concentration of cadmium in successive leaches was followed polarographically and the leaching process was terminated when the rate of cadmium dissolution decreased markedly. Chemical analysis of the intermetallic thus isolated is as follows: 11.5 wt pct Sc and 88.3 wt pct Cd. The composition of ScCQ is 11.8 wt pct Sc and 88.2 wt pct Cd. X-ray diffraction powder photographs of ScCds taken in a 114.6-mm Debye-Scherrer camera with CuKa, radiation can be indexed on the basis of a hexagonal nit cell. Lattice coonstants are a. = 6.330 ± 0.001A to 6.324 i 0.001A and co = 4.853 i 0.001A. The a0 has a slight range with the lower value seemingly associated with the cadmium-rich terminus of the phase. With eight atoms in the unit cell the calculated intermetallic density is 7.54 g per cu cm; the density as determined by a liquid-displacement method is 7.7 g per cu cm. Powder-diffraction data for ScCQ are recorded in Table I. Stoichiometry, symmetry, unit-cell dimensions, and the number of atoms per unit cell indicate the MgsCd (D019) type structure for ScCQ; space group is D,&-P6,/mmc. Atomic coordinates are:

Jan 1, 1964

By Nick Barton, Khosrow Bakhtar

Two plate load tests of 1 m2 area were per- formed in a pressure tunnel at the Rocky Mountain Pumped Hydro Project. Reaction for the 250 tons loading in this 10.5 meter diameter tunnel was provided by deeply anchored, diverging rock bolts, eight per load frame. Pressure build up to 2.5 MPa was provided by circular flatjacks. Rock deformation was recorded at depths of approximately 0.3, 0.9, 1.2, 1.8 and 3.3 meters using axially located multiple position borehole extensometers. The tests were performed in representative units of massive shale and thin to medium bedded siltstone. Stress was built up in four equal steps to 2.5 MPa, held constant for one week for creep monitoring, then unloaded, reloaded and unloaded over a period of one day. The most deformable unit was the massive shale which exhibited 1.3 mm of permanent deformation at the surface after the first loading and unloading cycle, which included 0.36 mm of creep. After the second loading-unloading cycle, the permanent deformation had increased to 2.6 mm, following a maximum deformation at the surface of approximately 3.6 mm. At the maximum stress of 2.5 MPa, the tangent modulus averaged 0.4 GPa when loading, and 0.3 GPa when unloading. The thin to medium bedded siltstone exhibited only 0.17 mm of permanent deformation at the surface after the first loading-unloading cycle, which included only 0.05 mm of creep. After the second loading-unloading cycle, the permanent deformation had increased to 0.27 mm, following a maximum deformation at the surface of approximately 0.53 mm. At the maximum stress of 2.5 MPa, the tangent modulus averaged 6.2 GPa when loading and 21.9 GPa when unloading.

Jan 1, 1986

By N Guresin, M Rohde

A lead-zinc flotation tailings sample containing silver from BHP Billiton’s Cannington Mine has been characterised to understand occurrences of silver in the tailings by conventional elemental, X-ray diffraction (XRD) and size analyses followed by mineralogical analysis with a scanning electron microscope (SEM) equipped with mineral liberation analysis (MLA) software and the use of an adapted diagnostic leach process originally developed for gold containing materials.The tailings sample contained 67 g/t Ag, 1.8 per cent Pb and 0.52 per cent Zn. The XRD analysis showed that the sample consisted of 74 per cent silicates, nine per cent sulfides, 11 per cent magnetite and small amounts of other minerals such as fluorite, fluorapatite and rutile. The p80 and p50 of the sample were determined to be 106 µm and 38 µm, respectively. The silver distribution was high in the small size fraction with 52.1 per cent of the silver being in the -8 µm fraction. The silver minerals freibergite, acanthite, jamesonite, pyrargyrite and native silver were observed in the mineralogical analysis of the sample by SEM/MLA. The associations of the minerals were intricate and the occurrences of silver were complex. There were finely disseminated silver minerals and also coarser grains of silver minerals in composites with the host minerals. It was estimated that almost 50 per cent of the silver was contained in pyrargyrite, around 14 per cent as native silver and contained in acanthite, 12.5 per cent in galena and around ten per cent in freibergite and jamesonite.These composite particles and the type of the silver minerals present were expected to limit leaching efficiencies of the silver in hydrometallurgical processing. The diagnostic leach tests showed that around 50 per cent of the silver could be recovered by direct cyanidation and higher extractions could be achieved by more aggressive acidic systems.Cyanidation tests were conducted to confirm the findings of the diagnostic leach studies. The investigated cyanidation parameters were time (up to 48 hours), solid to liquid ratio (1:1 and 1:2), cyanide concentration (0.025 M, 0.5 M and 0.1 M) and particle size (p80 of 106 µm, 63 µm and 7.5 µm). The effects of oxygen and lead nitrate were also studied. The tests were conducted at atmospheric temperatures. The maximum silver recovery obtained was about 50 per cent for all the parameter ranges trialled except particle size. The decrease in particle size from 106 µm to 7.5 µm by fine grinding resulted in an increase in silver recoveries from 50 per cent up to approximately 82 per cent indicating that the liberation of the silver grains/minerals is one of the factors affecting the cyanidation recovery of silver in addition to the presence of refractory silver minerals not amenable to cyanidation.Low head grades of silver in the tailings and relatively low cyanidation recoveries of silver (without fine grinding) necessitate a thorough cost analysis for the cyanidation of the Cannington lead and zinc tailings to assess if cyanidation would be a suitable process option for the extraction of silver. It is clear that one of the most important factors in determining the cost feasibility will be the price of silver in the world metal market.CITATION:Rohde, M, Guresin, N and Johnson, N W, 2014. Characterisation of silver minerals in lead-zinc flotation tailings and their response to cyanidation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 163–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By G Pattenden, R Hargreaves, P Pettit

"Even with the cyclic nature of mining, when it comes down to it, the bottom line is that whatever direction the commodity market is going there is always a desire to improve the economics of an operation in order to deliver a greater return to investors. Adapting to market pressures by introduction of an operational process change can often have a downstream impact. What may be less obvious is that reconciliation can play an important part in measuring the effectiveness of many operational changes. Through the adoption of best practice reconciliation and related comparisons, it is possible to measure the impact of changes across the mine value chain and identify variability that may have been introduced. Using analytical business improvement tools, examining and monitoring planned changes can be crucial in understanding whether the introduced changes have been effective and whether they have provided the expected result. Using several case studies, the authors will highlight the benefits provided by modern business intelligence tools, which can provide data validation and accurately report data trends related to both planned and unplanned change events.Citation:Hargreaves, R, Pattenden, G and Pettit, P, 2016. Measuring the Effectiveness of Change through Best Practice Reconciliation, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 71–83 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By R. Chanchani

Single and mixed mineral flotation behavior and the mechanisms for the loss of selectivity in 1:1 and 95:5 apatite: dolomite mineral mixtures are presented. Loss of selectivity in mixed mineral systems is attributed to depletion of oleate ions available for adsorption by bulk precipitation with calcium and magnesium ions dissolved from dolomite. Flotation after two-stage conditioning was found to be a potential technique to separate dolomite from apatite. This method involves conditioning at pH 10 followed by reconditioning at a lower pH. The results indicate that selective flotation of dolomite, a minor mineral in south Florida phosphate deposits, could be obtained by reconditioning at pH below 4.5. Higher selectivity was observed for mixed minerals as compared to that of single minerals.

Jan 1, 1986

The use of coal as a fuel causes air, pollution in; a number of different forms, and in nearly all stages of its, handling, preparation, storage, use and-disposal of its residue. First let us consider the handling of coal. As shipped, particularly to large utilities, it is run-of-mine bituminous made up of large chunks as well as pulverized particles. Because it &apos;is in an open car or barge, it is subject to the action o winds and the small particles may be blown around adding to the-particulate load in the atmosphere. Mien un¬loaded from the barge or car, there is again an opportunity for the wind to blow the fine particles around. All of us I am sure have seen a barge at the dock of a utility plant being unloaded by a clamshell bucket. This, after grabbing its load from the barge, lifts it some 60 or 70 feet and, then drops it on a conveyor, which carries the coal to a storage area.

Jan 1, 1964

By Gary P. Thomason

We have all heard a great deal about how various projects were financed or certain companies were successful in obtaining a bank loan. There are many more projects and companies who fail to get the money they need. At least a portion of these failures, and a large percentage of the frustrations connected with even the successful financings, are a result of not understanding the process of obtaining money. Recent years have seen a proliferation of sources available to finance minerals operations, but let me assure you that these represent only a minor portion of the minerals financing market. The fundamental source of borrowed money to almost all minerals related companies remains the banks. Therefore, understanding the "Loan Approval Process" can easily mean the difference between getting the money or not. In the following pages I hope to provide some insight into what I define as the loan approval process. Having pre-offered my definition, I intend to delineate the various stages of the process and the planning and information I believe should be contained in each. My ultimate goal is to help you think like a banker and, in so doing, stay on top of the process so that you can successfully obtain the funding necessary for your projects.

Jan 1, 1983

By Larry M. Southwick

Steel mill electric arc furnace dust is a RCRA listed hazardous waste and its treatment and/or disposal are regulated by a complex set of rules. These regulations were originally established to encourage recovery and recycling of valuable components. For EAF dust, the more valuable constituents include zinc, lead, cadmium and iron. In fact, current trends are in the opposite direction, as the regulations have complicated the ability to commercialize new treatment technologies and created substantial roadblocks and liabilities for processors. As a result, almost half of the EAF dust generated in 1997 will be landfilled. The problems are compounded by difficult processing requirements, less than sterling examples of technology development and mechanical and operating problems. This paper explores some options to simplify the processing requirements and thereby easing difficulties in commercializing new technologies and expediting the recycling of recovered metals. Dust processing usually includes a simple step followed by two complicated steps. The simple step is fuming of heavy metals away from iron and other residues. The complex steps are (1) separating and purifying the heavy metals and (2) upgrading the iron residue. The first complex step can be simplified by producing an intermediate product that is amenable to processing by zinc refiners. This route benefits from the currently underutilized (by dust processors) resource offered by refiners, who have experience in and existing processes for separation and purification of zinc-based heavy metals. Various processes and their associated product options are reviewed and compared. Future directions for dust processing developments are suggested.

Jan 1, 1998

[Scott Aberle Western Energy Co POB 99 Colstrip, MT 59323-0099 Randy Acre Joy Mining Machinery 2569 Silver Oak Ct. Grand Junction, CO 81505 Brian L. Acton Oxbow Carbon & Minerals Inc 1601 Forum P1-#P2 West Palm Beach, FL 33401 Laine W. Adair Genwal Resources Inc POB 1420 Huntington, UT 84528-1420 Kent Adamson Solvay Minerals POB 1167 Green River, WY 82935]

Jan 1, 1999

By N. E. Hanna

Experience with the current version of gallery test 4, in use since 1913 to evaluate the incendivity of permissible explosives in the presence of coal dust, has shown the procedure to have inadequate discrimination. Consequently the Bureau of Mines used the up-and-down method of statistical design to investigate the incendivity of permissible explosives in the presence of coal dust and gas. A suitable device was developed to measure coal dust concentrations in the air-gas mixtures and to disperse the dust in the gallery atmosphere. A proposed testing method which uses suspended shots in a predispersed coal dust-gas-air mixture was evaluated. The new method can discriminate between different explosives with respect to their incendivity. Maximum ignitibility of the coal dust cloud by permissible explosives occurred in the vicinity of 0.3 oz/cu ft. About 10% sodium chloride in permissible explosive formulations had a very significant effect in reducing the probability of igniting coal dust. Bundled charges were more incendive than column charges.

Jan 1, 1966

By Markus A. Reuter, Yongxiang Yang, Jim R. Post

In the upper part of an iron making blast furnace, sinter, coke and pellets are charged. While descending, the burden is heated and the iron oxides are reduced by the rising gases. The iron oxides start to soften and eventually melt. The melt and the remaining coke collect in the lower part of the blast furnace: the hearth. The remaining coke forms a porous bed: the dead man (see Figure 2). The melt flow through the dead man can affect substantially the hearth lining life, the furnace productivity and product (i.e. hot metal) quality. Physical characteristics like porosity and particle size distribution of the porous coke bed play a critical role. Because of the distributed nature of the coke properties, the bed packing structure and porosity will not be constant.

Jan 1, 2003

Jan 1, 1933