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All the Technical PUBlications and Preprints published in 1932 are available at Institute headquarters. They are also on file in public, university and technical libraries and, when so indicated in the list, may be found in the Transactions. Copies of the Technical Publications have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Insti-tute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Copies of Preprints may also be obtained from the Secretary's office. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. Nonmembers may purchase the papers at the prices mentioned. Metal Mining Technical Publi- Title Author Meeting Trans. cation Volume No. and Page* 484-A.45 Propeller Type Mine Fan at Moose A. S. Richardson New York 102, 88. 95 F.52 Shaft. Butte. Montana (13) Feb.. 1932 487-A.46 Progress in the Improvement of Max H. Barber New York. Methods and Equipment at Feb., 1932 Open-pit Iron Mines on the Lake Superior Iron Ranges (9) Pre. Sand Filling through Pipes and Lucien Eaton New York, 102, 33, 41 Boreholes (9) Feb., 1932 Milling And Concentration 445-B.37 Soap Flotation of the Nomulfides Will H. Coghill New York. H.19 (18) J. Bruce Clemmer Feb., 1932 461-B.38 Principles of Flotation—An Experi- I. W. Wark New York. mental Study of the Effect of A. B. Cox Feb.. 1932 Xanthates on Contact Angles at Mineral Surfaces (48) Iron and Steel Division 447-C.81 Electrochemical Potentials of Nitri- Shun-ichi Satoh New York, fied Steels (31) Feb.. 1932 450-C.82 Reaistanoe of Iron-aluminum Alloya N. 9. Ziegler New York. 100, 267. 670 E.143 to Oxidation at High Tempera- Feb., 1932 tures (8) 451-C.83 Pressure Welding of Low-carbon C. H. Austin New York. Steela with Theoretical Con- W. S. Jeffries Feb.. 1932 siderations on the Mechanism of Such Welding (42) 453-C.84 Inclusions—Tbeir Effect, Solubility C.E.Sims New York, 100, 154, 176 and Control in Cast Steel (24) 0. A. Lillieqvist Feb., 1932

Jan 1, 1932

By G. S. Scott, G. W. Jones, I. Spolan, R. E. Kennedy

In studies made by the United States Bureau of Mines to determine the causes of explosions in medium-pressure acetylene generators , it was shown that when these are operated at elevated temperatures the acetylene liberated in an acetylene generator carries enough water vapor to heat certain types of carbides to a high temperature , when the acetylene- water vapor mixtures are passed through the carbide . This report contains results of further work carried out to develop an apparatus to show the heating effects or reactivity of various types of carbides in contact with acetylene - water vapor mixtures .

Apr 1, 1947

By J. A. Finch

A closed grinding circuit, typified by a ball mill-cyclone combination, is often required to treat a feed comprised of a variety of minerals of differing properties. Usually, the individual behaviour of the minerals is not assessed, a procedure which requires sizing and metal or mineralogical assaying of each size fraction. Further, sizing is frequently by screening to perhaps 325 mesh meaning that detail on the important -44 um fraction is unavailable. It is well appreciated that minerals can exhibit both individual classifying and grinding behaviour. Recognizing that cyclone classification results from differential centrifugal settling and acceleration rates, then minerals of differing specific gravity will exhibit individual mineral cyclone performance curves. If the minerals have differing grindabilities, then individual mineral rates of breakage may be expected. When treating an ore containing minerals of a range in specific gravity and/or grindability, individual mineral behaviour in the closed-circuit grind could be notable and perhaps important to the overall concentrator performance. An example is a lead-zinc ore, as shown by Kelsall et al.(1,2) This paper describes the individual mineral cyclone performance curves at sizes down to ti 10 um for the four major minerals at two lead-zinc concentrators; the Sullivan concentrator at Kimberley, British Columbia, and the Pine Point Mines concentrator at Pine Point, North West Territories, both operated by Cominco Ltd. In addition, individual mineral grinding behaviour for the four major minerals at the Sullivan concentrator is presented.

Jan 1, 1977

By S. S. Klima, J. A. Organiscak

Researchers at the National Institute for Occupational Safety and Health (NIOSH) performed laboratory testing to examine and improve airborne dust capture and methane removal performance of flooded-bed scrubbers on continuous mining machines using a blowing face ventilation configuration to reduce respirable dust exposure to shuttle car operators. Several testing conditions were examined to minimize shuttle car operator dust exposure without adversely affecting continuous miner performance and production. Curtain-to-face setback distance of 9.1 m versus 15.2 m (30 ft versus 50 ft), face ventilation airflow of 226.5 m3/min versus 339.8 m3/min (8,000 ft3/min versus 12,000 ft3/min), and the use of side-body-mounted blocking sprays (on versus off) were the three primary parameters compared. Scrubber airflow was set and maintained at 198.2 m3/min (7,000 ft3/min) throughout testing. An examination of slab cuts versus box cuts and the location of the shuttle car (present behind the continuous miner versus not present in the entry) was also performed to demonstrate the effects of these constantly changing scenarios on scrubber performance. Results show that the best blowing face ventilation setup for minimizing shuttle car operator dust exposure for the tested parameters uses a 15.2-m (50-ft) curtain-to-face setback with 339.8 m3/min (12,000 ft3/min) face ventilation while operating the side-body-mounted blocking sprays. INTRODUCTION Coal mine worker overexposure to respirable coal dust continues to be a problem in U.S. underground coal mining operations, potentially leading to coal workers’ pneumoconiosis (black lung). The U.S. Mine Safety and Health Administration (MSHA) requires that respirable dust exposure to coal mine workers does not exceed a 1.5 mg/m3 average over the actual working shift (79 Fed. Reg. 24814 (2014)). Although using a blowing face ventilation configuration on continuous miner (CM) sections is beneficial for removing methane emissions from the mining face, it can be detrimental for dust control for shuttle car (or ram car) operators and any other workers on the return ventilation side of the CM when compared to exhausting ventilation. Even with machine-mounted scrubbers on CMs, shuttle car operators still have some of the higher dust exposures with blowing face ventilation systems (NIOSH 2011, Beck et al. 2015). Although scrubber discharge air is not completely clean, dust being blown around the scrubber inlet and therefore not being captured by the scrubber can further increase these dust exposures (Goodman 2000). Dust control problems are also caused by inadequate face ventilation quantities causing scrubber face airflow recirculation issues (Schultz et al. 2010). In order to minimize respirable dust exposures on blowing face ventilation sections, ventilation, water spray, and scrubber parameters were experimentally examined to improve operating ranges for both dust and gas control. Several blowing face ventilation factors were examined with respect to CM spray systems and scrubber operation. Curtain-to-face setback distance and side-body-mounted blocking sprays were previously examined in the laboratory for dust control on a full-scale CM model using a scrubber on a blowing face ventilation system (Goodman 2000). The blocking sprays produced larger dust reductions at the CM’s rear corners and return for a 6.1-m (20-ft) curtain setback distance as compared to a 12.2-m (40-ft) curtain setback distance with equal face and scrubber airflows of 169.9 m3/min (6,000 ft3/min). Because face ventilation airflow quantities, shuttle car operator locations, and tracer gas concentration gradients were not previously examined during these experiments, additional research was required to determine improved operating parameters for blowing face ventilation systems.

Jan 1, 2019

By Joseph A. Sutton, John D. Corrick

The chemistry involved in the microbial dissolution of iron and copper from such sulfide minerals as pyrite, chalcopyrite, chalcocite, cove11ite, and bornite is described. The chemical criteria used to evaluate the activity of microorganisms on these minerals were changes in pH, ferric iron produced, and oxygen consumption. In a series of experiments in which a ferrous sulfate nutrient solution was percolated over small portions of the above-mentioned copper sulfide minerals for 56 days, the iron-oxidizing bacteria Ferrobaci11us ferrooxidans and Thiobaci11us ferrooxidans were capable of bringing about the dissolution of 23.7 percent of the copper from chalcocite, 56.3 percent of the copper from cove11ite, and 29.8 percent of the copper from bornite by the microbial production of ferric sulfate which reacted with these minerals. Laboratory tests have demonstrated that pure strains of the iron-oxidizing bacteria act as catalysts to the ferrous iron being oxidized by the Oxygen of a system containing pyrite and chalcopyrite. In a series of experiments during which nutrient solution was percolated over pyrite for 70 days, the ferric iron produced by the iron-oxidizing bacteria was 112 to 120 times greater than that produced atmospherically.

Jan 1, 1964

By Mary S. Esfandiary

This is a revision of a directory of coal research organizations throughout the world that was first published in 1961 as Bureau of Mines Information Circular 8008. Because of the wide acceptance of the first edition, a revision which would supply up-to-date information on coal research and which would facilitate communication among organizations of similar interest seemed important. This compilation includes the names and activities of organizations of various types-government, university, private, and industry. The areas of investigation that each organization is engaged in are indicated in broad terms: Analysis and constitution, mining and geology, preparation, briquetting, combustion, high-and low-temperature carbonization, gasification, conversion to solid and liquid fuels, and health and safety. Publications issued by and describing the work of each organization are cited; almost all of the organizations also publish results of their investigations in the technical press. Selected technical and trade publications that publish information on the science and technology of coal and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country. Information that would improve coverage and accuracy of the next revision of the publication will be welcomed by the Bureau of Mines.

Jan 1, 1966

By J. Morris, R. Sellaro

Petro-diesel is a common collector for coal flotation, but the partitioning of diesel range organics (DROs) in process streams has not been widely studied. Preliminary research suggested that under normal dosing schemes total residual DRO contents in process waters should be limited to the sub-ppm water-soluble fraction (WSF). Further, polycyclic aromatic hydrocarbons (PAHs) should partition proportionately with DROs. The purpose of this study was to confirm these findings in laboratory flotation tests. Total DRO and specific PAH contents were measured in the waters associated with the concentrate and tailings streams. The results show that concentrate waters consistently had higher amounts of DROs than tailing waters. Moreover, the DRO contents in both streams generally increased with increasing diesel dosage. In line with preliminary research, DROs appeared to be limited to the WSF, and PAHs tended to partition proportionately with DROs. Under typical operating conditions, it appears that residual DROs should not present an environmental concern, but conditions should be avoided that allow significant overdosing of diesel.

Jan 1, 2014

By R. E. T. Hill

"A laboratory study was undertaken to determine the condensed equilibrium phase relations at 600°C in that portion of the quaternary Fe-Ni-Cu-S system which lies in the neighbourhood of the monosulphide solid solution (MSS). The study sought to determine to w hat extent copper affects the temperatures of stability and compositions of iron-nickel sulphides in bulk compositions similar to those of massive Fe-Ni-Cu ores. Experimental data, including stable phase assemblages and phase compositions, are presented.In the quaternary system at 600°C MSS forms stable phase assemblages with pentlandite, chalcopyrite solid solution, pyrite and vaesite. Over the range of bulk compositions displayed by natural ores copper as well as metal/sulphur ratio have a significant effect on the thermal stability of pyrite and pentlandite. Errors therefore accompany the widespread practice of ignoring copper or chalcopyrite when the mineralogical and compositional changes that have accompanied the initial cooling of primary magmatic sulphides or their subsequent homogenization during isochemical metamorphism are being deciphered. These errors are most significant for ores the bulk compositions of which lie tow ard the sulphur-deficient side of the cupriferous MSS. Temperatures as much as 300°C above the copper-absent value are possible for the interpreted upper stability limits of pentlandite in these ores.The experimental data show that up to 2.0 at% copper can occur in pentlandite stable at 600°C in a bulk composition equivalent to natural magmatic ores. This is equivalent to nearly 10 vol% chalcopyrite. Pentlandite contains more copper than coexisting MSS and the copper content of both phases increases with increasing iron."

Jan 1, 1984

By Parviz F. Rad

The increased use of tunnel boring machines (TBM) has stimulated laboratory research to optimize the cutting parameters of these machines with the objective of increasing machine efficiency and penetration rate. Laboratory-scale rock cutting experiments have succeeded in identifying many of the important parameters involved in rock-cutter interaction. Although scaling factors may be required to apply the results directly, the concepts developed can be used qualitatively as design guidelines for boring machines. The Bureau of Mines Twin Cities Mining Research Center has recently developed a large-scale rock cutting device (RCD) that will simulate many of the operating parameters of the tunnel boring machines in the laboratory under a controlled environment. The results of the experiments with this device will be directly applicable to the design of TBM's.

Jan 1, 1973

By Andrzej Wieniewski, Cezary Regula, Bozena Skorupska, Krystian Cichy

"In this paper, experiences from Polish non-ferrous metals ores enrichment plants in the copper and blende concentrates quality improvement are discussed. The blende concentrate being produced in ZGH Boleslaw S.A., with Zn content of about 54,5% is characterized by the relatively high magnesium content reaching a level of 1% resulting from the dolomite presence, while for the zinc production by electrowinning a concentrate in which magnesium content should not exceed 0,3% is required. The implemented new technology for the quality improvement of blende concentrate is based on the leaching of zinc concentrate with sulfuric acid aimed at dissolving of the contained dolomite, and then flotation of the leached concentrate. It allows to obtain a concentrate with magnesium content below 0,1% at the simultaneously increased zinc content to about 57,5%. In the paper, laboratory tests results on the development of optimal flotation flowsheet for the gypsum removal and the industrial tests results concerning the process optimization of this flotation are discussed. In turn, the copper concentrate being produced in Polish copper ore enrichment plants KGHM PM S.A., is characterized by the increased organic carbon content - above 8%. It creates problems with the smelting of this concentrate because of difficulties with the heat removal derived from the combustion of organic carbon in the flash smelting process. The implementation of segregating flotation to the industrial practice allows the effective production of two concentrates with the differentiated chemical compositions - a concentrate with increased copper content and reduced organic carbon content for the flash smelting process, and a concentrate with lower copper content and increased organic carbon content for the shaft smelting process. In the paper, conditions of the segregating flotation and the achieved results are described."

Jan 1, 2014

By Thomas S. Mackey

The industrial types, sources, and quantities of USA tin residues are identified and the methods of treatment reviewed. The effect of a lower tin price, due to a current major world surplus of tin metal, is mentioned and covered in some detail. The names and locations of over 100 USA firms recovering tin residues are listed. Current smelting and refining charges are included to convert the residues into tin metal and alloy. The impact of the suspension of the LME daily tin price since October 24, 1985 to date, and the failure of the International Tin Council to support the Buffer Stock Manager are reported with comments.

Jan 1, 1986

By D. V. Bush

There has been a great deal of evaluation and discussion on the economics of semi- autogenous grinding versus conventional grinding circuits. This paper will not discuss the merits of one system over the other, but rather will discuss the Henderson Mill's approach toward achieving the most economical milling conditions in its existing SAG mills.

Jan 1, 1985

By T. W. Turk, S. A. Sass

The engineering design features of the Mercur Gold Project crushing, grinding, carbon-in-leach, bullion, reagent, and tailings disposal areas will be discussed in this paper. It presents a project overview and flowsheet along with selected design alternatives. During the engineering phase, major equipment and other features were selected to optimize design within site location and environmental constraints. The project team organization and procedures were adopted to accommodate multiple optimization studies while maintaining a tight engineering schedule.

Jan 1, 1985

By A. J. Smethurst, S. B. Hearn, S. Boskovic

"The problem of crud in solvent extraction is well known and can be a major handicap and operational issue. Colloidal silica can cause a number of problems including interfering with flocculation, initiating crud formation in solvent extraction (SX), decreasing SX extraction kinetics and increasing SX phase disengagement times. Flocculation can be utilized to remove some of the troublesome particulates but colloidal silica does not flocculate well and presents a different problem requiring innovative chemistry to solve. Coagulants can assist by facilitating the removal of this colloidal silica by promoting the agglomeration of the particles to a size which can be more readily settled or flocculated in solid/liquid separations. This is achieved when the coagulants bind to the surfaces, displacing water and destabilizing the colloids, whereupon they bind to each other which facilitate their amenability to conventional flocculation.INTRODUCTIONSilicate minerals are abundant in the upper layers of the Earth’s crust, and there are few mineral deposits without significant levels of gangue silicates. Silicate minerals include the pure silicas, such as quartz and other silicate containing minerals such as clays, chlorites, feldspars, as well a vast number of less common silicates.During the acid leaching of ores, two types of fine silica particles are released in solution from the dissolution of the host mineral. The first consists of partly depleted silicates, and the second is colloidal silica, which forms in solution. It is this second type which has the potential to cause crud formation as well as poor solution clarities, slow filter rates and excessive flocculant usage (Figure1)."

Jan 1, 2016

By R. J. Sweigard

Estimated costs and revenues can be used in the evaluation of post- mining land use alternatives. However, post-mining land use decisions have to be made in an environment complicated by several additional factors. These factors, including cultural, natural, and managerial issues, are not as easily quantified as costs and revenues but may be more important determinants. There- fore, some approach is needed to attach relative weight to the various factors. The concept of fuzzy sets assembled into a structured hierarchy facilitates analysis of the relative value of individual factors and their impact upon each alternative under consideration. In this paper, a method is presented which employs fuzzy set analysis to evaluate postmining land use plans on the basis of these nonquantitative factors.

Jan 1, 1986

By Heikki K. Jalkanen

Thermodynamic properties of copper-iron mattes and slag-matte distribution of copper and some minor matte constituents (Ni, Co, Mo, As, Sb and Bi) are discussed on? the basis of equilibrium measurements: a change from. oxidic to sulfidic solubility as the predominant form of dissolution of copper takes place as matte grade decreases. Distribution coefficients of minor matte constituents are complex functions of sulfur and/or oxygen potentials?. The distribution behaviour of different? metals can be qualitatively derived from their affinities to copper and stabilities. of their sulfides and oxides. The equilibrium results are compared with commercially observed values. from Outokumpu.Oy flash smelting furnace.

Jan 1, 1983

By Carlton E. Brown

This report contains information on the cells or containers used to hold a known small depth (usually 1 mm. or less) of the dust-containing liquid from impinger, 5/6/ filter-paper,7/ and other samples collected from the air while the particles revealed by a microscope (equipped with a 16-mm., 0.25- or 0.50-N. A. objective and ordinarily used with axial light-field illumination) are counted in order to obtain an index of the concentration of dust in the sampled air. Information is given on such subjects as the kinds of cells available, kinds used, actual depths of cells, and construction of simple, inexpensive cells. ACKNOWLEDGMENTS The interest, encouragement, and assistance received from H. H. Schrenk, chief chemist of the Health Division, in the preparation of this report are gratefully acknowledged, as 'is all other assistance received.

Jan 1, 1945

By H. H. Stout

In the early fall of 1925, the writer was conducting, in the Ledoux and Co. laboratory, New York, experiments directed toward ascertaining the effect on its impurity content when cathode copper was subjected to a current of various gases at an elevated temperature below the melting point. The apparatus consisted of a vertical I-in. dia. silica tube about 12 in. long, heated on the outside. The cathodes were broken to pass 3/8-in. mesh, and a current of various different gases was passed up through a 4-in. long column of these loose cathode particles in the vertical tube furnace. Temperature was maintained to 1500º to 1600ºF. and the gas treatments lasted from 3 to 6 hr. The writer observed that whenever reducing gas (H2 or CO) was used, these cathode particles stuck together at points of contact with each other. The cohesion was so marked and tenacious that an examination was made of the fractured surfaces, when cathode particles were broken from the cluster. Crystal growth was always found to have taken place across the surfaces where separate particles were in contact, but only after all oxides, sulphates, etc., had been completely removed. The idea of a possible new process was then conceived and was disclosed to A. M. Smoot (V. P. Ledoux and Co.) with intent to obtain his views. The first conception as given Smoot was "to gas-clean broken cathodes, put them in an extrusion press, solidify and extrude them at around 1500ºF." Smoot's reaction, after a few moments considera- tion, was, "It looks perfectly all right to me.'' The writer and his assistants, W. H. Osborn and H. H. Stout, Jr., after conferring as to ways and means, decided to go ahead with preliminary laboratory experiments, which, it was thought, would move the new process from the possible to the probable. This program followed a course indicated by three basic considerations: 1. Since brittle cathodes were often unintentionally produced, it seemed probable that the laws controlling this type of deposition could be ascertained. 2. We had already proved the gas-cleaning feature. 3. There remained to prove: whether a sound, homogeneous metal billet could be produced with crystal growth established over the entire surface of each individual particle in the billet; and, if so, what would be the physical properties? Osborn arranged with Columbia University for conducting experiments in its research laboratory to prove or disprove the third item; Columbia assigned C. A. Phillipi, Jr. to assist in the project. A press with a cylinder 2 in. high and of I-in. dia. was used. It was surrouilded and heated by a resistance coil 01 Nichrome wire. Broken tough cathodes were used. Experimental Procedure The first run took place March 18, 1926. The resistance wire gave out when temperature of 1000ºF. was obtained. Pressure was immediately applied: perceptible ram movement stopped when 39,000 lb. per sq. in. on the copper was reached, with a maxi-

Jan 1, 1941

By P. W. J. Delport, E. Du Toit

Investing in a mining venture can be risky and stakeholders need transparent, unbiased reports to understand the Mineral Resources and Mineral Reserves a mining company holds. Readability and textual choice can be used consciously to manipulate perceptions, or it can be done unconsciously. This exploratory study investigates the readability and textual choice of supplementary Mineral Resources and Mineral Reserves Reports of companies listed on the Johannesburg Stock Exchange. The results indicate that narrative manipulation occurs in these reports through word choices that make the reports difficult to read, as well as specific narrative selections. This reduces the informational value of the reports. The results of the study will be useful to various stakeholders, such as mining company management, investors, investment specialists, financial analysts, and even employees and the general community, who all use these reports to make important decisions. It is also useful for the preparers of the Mineral Resources and Mineral Reserves Reports, Competent Persons, and other technical specialists to be aware of readability and that certain textual choices can affect the interpretation of these reports. It is recommended that bodies such as the JSE and the SAMREC and SAMVAL Code committees consider adding a plain language requirement to regulations, guidelines, and codes to ensure transparent, unbiased, and objective reports.

Mar 1, 2021

By W. H. Patterson

The history and experience of early companies in the Islands is illustrated by the typical transactions of Trans-Western from 1959 to date. Trans-Western had entered into farmout agreements with companies strong enough to carry out at least the required minimum exploratory work and then such development as might be warranted. The farmee companies were required to make deposits to guarantee work performance during the first period of validity, i.e. the first 3 years of the 12-year life of the permits, and at the rate of 5 cents per acre. At that time, a good deal of geology was available, as a result of extensive exploration that had been carried on by the Geological Survey of Canada and other geological enterprises, with field parties travelling over and camping on all of those Islands. Trans-Western's farmees then selected, from Trans-Western's priority on 13.5 million acres, what they believed were the lands most prospective of producing large oil and gas discoveries, and, having the right to trim off acreage which they considered less prospective, thereby reducing the acreage of Trans-Western and its farmees to in excess of 5.5 million acres. The farmees then commenced a 3-year program carrying out geological exploration to the required minimum of 5 cents per acre, and with some permanent and many mobile camps.

Jan 1, 1969