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By J. A. Brusset

THE Adanac mine was opened by West Canadian Collieries, Ltd. in 1943, and the question soon arose as to which system of haulage should be selected. Compressed-air locomotives and ropes were rejected on the ground of high cost. Since under the Alberta Mines Act the use of trolley locomotives underground in coal seams is not permitted, the choice lay between storage battery and Diesel locomotives, The preference of the author, who had experience with both in gassy French coal mines prior to 1930, was for Diesel locomotives due to lower cost of installation and greater flexibility and reliability. It was realized that the adoption of Diesels would be somewhat of an innovation since in the United States the mining laws prohibit their use under- ground in coal mines, and in Great Britain in 1943 their use was only in the incipient stage. By 1945, 25 Diesel locomotives were in use underground in gassy mines in Great Britain, and approval had been granted for the use of an additional fifty of two approved types also for gassy mines. Numerous special regulations of the British Coal Mines Act have been formulated to govern the use of Diesel locomotives. For instance, they are not allowed closer than 200 yards from the working face; daily inspections are required; and a weekly checkup and cleaning must be given the engine by a competent engineer. Also, methane content of the air in the roadway can never exceed 1.25 percent, and daily checks must be made if it exceeds 0.75 percent. Under Alberta regulations, we were required to use a flameproof type engine, to be used only in fresh air intake. The engine fumes had to travel along a separate ventilation split where no man was permanently employed. It is forbidden to run a

Jan 1, 1949

By L. A. Cowan

IF the elements of personality be those characteristics in which humans differ, and if this definition be applied to the purchasing department for the Climax operations in Colorado, it must he concluded that this department has no distinguishing traits that would give it a departmental personality different from that possessed by the similar department of any progressive mining enterprise. Or, one may go further by stating that the rudimentary functions of any purchasing practice employed principally in the acquisition of maintenance, repair, and operating supplies are much alike, whether or not the industry involved be mining or milling. However, in the fact that the principal purchases of a mining company are materials for maintenance and repair and consumable operating supplies lies that essential characteristic which differentiates mining and milling purchasing functions from those of the manufacturer, the fabricator, or the ordinary processor.

Jan 1, 1946

By WM. E. Mlligan

IN the last year, much information had become available as to the extent that zinc participated in the war effort. The importance of foreign zinc in this program had been indicated by Bateman (M&M April 1945) as of the order of 400,000 tons annually in zinc or contained zinc. Pehrson (M&M April 1945) reviewed the domestic ore-reserve situation with respect to most minerals and metals and showed the extent to which commercial zinc ores had become depleted in this country. This picture was further darkened by O.P.A. figures appearing in E.&M.J. July 1945 in which figures for total production during the three previous years were broken down into percentages produced under ceiling and various quota price categories. True, factors other than depleted ore reserves contributed to this picture. Among the more important of these, were shortage and high cost of labor, both skilled and unskilled, and the general difficulty and cost of maintaining adequate equipment and supplies. The cost of production in the Tri-State district was most affected.

Jan 1, 1946

By Dagoberto Brandão Santos, Kairo de Barros Guimarães, Túlio Magno Füzessy de Melo

The effect of the cooling conditions on the microstructure and hardness of a Dual Phase hot-rolled steel 800 MPa strength was investigated. Simulations of the cooling conditions using a dilatometer were carried out from samples of a hot rolled coil with variations of the intermediary temperature from 620 to 740°C, isothermal holding time between 1 and 10 s and coiling temperature between 50 and 400°C. In addition, two CCT (Continuous Cooling Transformation) diagrams were developed to evaluate the effect of the isothermal holding time on the phase transformations of the remaining austenite. It was observed that the intermediary temperature has a strong influence on the kinetics of the phase transformation, as well as the isothermal holding time influences the amount of ferrite formed and, consequently, the final microstructure and hardness of the material. The coiling temperature did not cause significant changes in the amount and morphology of the ferrite, but a gradual replacement of martensite with bainite was observed, which, in addition to the self-tempering effect, contributed to the hardness reduction.

Oct 1, 2019

By Hemant Agrawal, Arvind Kumar Mishra

Rock breakage using blasting is one of the important operations of the mining industry. The delay timing decides the initiation sequence of holes in the blasts and is a crucial factor to improve the overall blast performance. Blast-induced ground vibration is an undesired yet unavoidable outcome of blasting. Peak particle velocity (PPV) is commonly used to measure the magnitude of blast-induced ground vibration. Channelization and better utilization of explosive energy delay are provided between blast holes using initiating systems. The use of different initiation systems even on the same site results in a very significant difference in the values of PPV generated. Due to scattered delay timings of pyrotechnic detonators, the scaled distance predictor equations obtained become unreliable. The error/scatter in delay timing leads to overlapping of holes and hence increases in maximum charge per delay. In this paper, an analytical approach has been discussed to measure the overlapping of holes during blasting with initiation systems having inherent cap scatter. The analytical approach will be calculating the probable overlapping of holes due to scatter in delay timing and will help blasting engineers to understand the variation in maximum charge per delay due to pyrotechnic based initiating systems. In this study, a total number of 102 blasts were conducted using different initiation systems at two different opencast coal mine and 221 corresponding blast vibrations events were recorded.

Nov 10, 2020

By Sushil Bhandari, Amit Bhandari

In this paper, a case study is presented of a large global cement company using a cloud and mobile based platform across 17 of their mines consistently over a large number of users over a period of over two years. The use of a blast platform is detailed which include blast designs, blast data collection and the trends in terms of results.

Feb 1, 2020

By Cyril Stanley Smith

ARCHEOLOGISTS, by use of the terms Bronze Age and Iron Age, indicate that metals have in the past determined the character of civilization. The relatively simple discovery by a primitive metallurgist that the addition of tin to copper both facilitated the production of castings and increased the durability of the product enabled hunter, warrior, and housewife alike to do things never dreamed of before. Similarly, the smelting of iron and the discovery of hardening methods greatly changed the arts of peace and war. Discoveries of low-melting-point alloys for joining and for making household utensils, and perhaps the adornment of a feminine form by sparkling precious-metal jewelry, have at times changed the destiny of a country. Bronze cannon, the cast and wrought iron Watt engine, copper transmission lines, and aluminum alloy aircraft, are cases of particular metals making possible the realization of an improved engineering design. Perhaps of the greatest influence of all upon civilization was the development of type metal. The rapid increase in the rate of dissemination of knowledge dates from the day that the technique of the pewterer was utilized in making rapidly reproducible and accurately sized letters for printing. It was not movable type, but metal type that was important, for metal castings could be made of identically the same shape and size at an enormous rate, and possessed excellent inking and wearing characteristics.

Jan 1, 1946

By Jon A. Hummer, MICHAEL R. SHAHAN, Aleksandar D. Bugarski, Shawn Vanderslice

A study was conducted in an undergroundminewith the objective to identify, characterize, and source apportion airborne aerosols at the setup face and recovery room during longwall move operations. The focus was on contributions of diesel- and battery-powered heavy-duty vehicles used to transfer equipment between the depleted and new longwall panels and diesel-powered light-duty vehicles used to transport personnel and materials to various locations within the mine. Aerosols at the setup face were found to be distributed among diesel combustion-generated submicrometer and mechanically generated coarse aerosols. According to the data, the submicrometer aerosols downstream of the setup face were sourced to diesel exhaust emitted by vehicles operated inside and outside of the panel. Depending on the intensity of the activities on the panel, the outby sources contributed between 12.5 and 99.6% to the average elemental carbon mass flow at the setup face and recovery room. Extensively used light-duty vehicles contributedmeasurably to the elemental carbon concentrations at the setup face. The number concentrations of aerosols downstream of the setup face were associated with aerosols generated by combustion in diesel engines operated in the shield haulage loop and/or outside of the longwall panels. Entrainment of road dust by diesel or battery-powered load-haul-dump vehicles operated near the measurement site appears to be the primary source of mass concentrations of aerosols. The findings of this study should help the underground mining industry in its efforts to reduce exposures of miners to diesel and coarse aerosols.

Apr 14, 2020

By MARK J. VANARELLI

Estimating groundwater inflows in rock deep tunnels is critical to the safety of personnel constructing the tunnel and the cost of construction. This paper presents two case studies for estimating steady-state groundwater inflows into deep rock tunnels. The case studies included the Chattahoochee and Nancy Creek tunnels. In this paper, statistical methods were applied to packer test data obtained from exploratory borings during geotechnical site investigations. A semi-empirical procedure was utilized for estimating groundwater inflows into these deep rock tunnels. It is the most widely used method/procedure in the tunnel industry. The Chattahoochee and Nancy Creek tunnels are deep rock tunnels which exhibit radial flow conditions. For the radial flow condition, a statistical analysis presented in this paper indicates that the semi-empirical procedure works well; however, variations in the procedure and/or an insufficient amount of testing could lead to underestimations of the inflow quantities. Packer test data plotted in histograms were observed in all cases to be log-normally distributed for the radial flow condition. Modeling using Monte Carlo simulations was observed to be an effective tool for removing irregularities in the distribution of the data and incorporating high-end permeability data to derive reasonable groundwater inflow estimates. This paper is based on the PhD thesis entitled “Improvements to the Current State of the Practice in Steady-State, Groundwater Inflow Estimates into Rock Tunnels based on the Application of Statistical Analysis Methods of Packer Test Data obtained from Exploratory Borings During Geotechnical Site Investigations.”

Oct 9, 2020

By Liaqat Ali Shah, Muhammad Farooq, Zait Ullah Shah, Francisco Rolando Valenzuela-Díaz

Bentonite collected from Nowshera (Pakistan) was treated with NaCl, and the < 2-μm clay fractions were separated by sedimentation process. The textural changes in NaCl treated purified bentonite were compared with raw and physically purified sample. It was detected that the NaCl-treated purified bentonite and the sample purified by simple sedimentation, respectively, consist of sodium-montmorillonite and calcium-montmorillonite as a major clay mineral. The honeycombed-type morphology was observed for both the purified samples; however, the particles of NaCl treated purified bentonite were relatively in a compact form. The particle sizes of both the purified samples were found considerably smaller. The high volume percent of the fine particles was noticed in the NaCl-treated purified bentonite. This attributed that the sodium exchange has a valuable impact on the bentonite dispersion in aqueous media during particle size measurement. The relatively high mesopore area/volume and micropore area/volume and specific surface area (SSA) were detected in purified samples. The NaCl-treated purified sample showed relatively high mesopores area/volume than the sample obtained by simple sedimentation. These changes seem to be originated from either high montmorillonite contents and/or the smaller particle size, which might be produced after the layer rearrangement during the interlayer cation replacement by Na+ ions. The large SSA and high porosity of purified samples particularly the NaCl-treated bentonite suggest their potential use as adsorbents, catalysts, pharmaceuticals, and cosmetics.

Jan 7, 2021

By Sheldon P. Wimpfen

RESEARCH is undertaken to find out what must be done when what we are doing now is no longer adequate. To accomplish this end, researchers apply the truths of nature to industrial evolution. A survey conducted with the co-operation of 58 universities and colleges offering degrees in mineral engineering was the basis for the table accompanying this article. This survey was undertaken with the object of presenting to faculties and student bodies, as well as to industry, all available information on what action the educational institutions of the country have taken to provide the properly trained researchers so vitally needed. A hoped for result is that the great variety of opportunities available will encourage some undergraduate students to continue in their field beyond attainment of a B.S. degree.

Jan 1, 1947

By Randolph C. Specht

A two year study was made of the waste disposal of the pebble rock phosphate industry. Solid slimes are impounded in large settling areas and the process water is re-used. Clear effluent was not found to be toxic to fish, or animal life in field tests or in controlled experiments.

Jan 1, 1950

By Rollin A. Pallanch

THE Midvale mill of the United States Smelting Refining and Mining Company is situated on a flat site whose elevation is 50 ft above that of the Jordan River. Tailings are impounded in the area between the river and the flat upon which the mill and railroad switchyard are located. The water supply is pumped from the Galena canal which leads from the river at a point some ten miles to the south. The mill has a present capacity of approximately 1700 tons daily. It started out originally in 1926 as a 750 ton three-unit plant. The tonnage was gradually increased to 1200 tons by 1934, and in late 1935 a fourth unit was added. The accompanying flowsheet shows the principal equipment and how it is utilized. The ore is principally sulphide with varying degrees of oxidation, with individual lots ranging widely in both precious and base metal content. In each of the four individual units of the mill there will often be mixtures of as

Jan 1, 1948

By E. J. ENGEL

The New York talc deposits of commercial importance are in St. Lawrence and Lewis counties, in the northwest Adirondack Mountains (Fig 1). All of the deposits are of pre-Cambrian age and occur within highly deformed and recrystallized marble of the Grenville series. The deposits in St. Lawrence County, near Gouverneur, are the largest and most productive of their type known in the Western Hemisphere. In 1948 the seven mines which are in operation will produce about 130,000 tons of ground talc. All talc production in Lewis County is from one mine. There the annual production ranges from 15,000 to 30,000 tons. These so called talcs of New York State include earth materials of differ- ent chemical and mineral compositions. In general the mineral talc is sub- ordinate in amount to other minerals in both the Gouverneur and Natural Bridge deposits.

Jan 1, 1949

By Agung Wibowo

The incident of Ammonium Nitrate explosion in Beirut on August 4, 2020, became a wake-up call to Ammonium Nitrate stakeholders for mining and construction regarding the deadly risks associated with explosives management. This is a very expensive a lesson learned for all parties involved in the storage of explosives.

Feb 1, 2020

By Jonathan D. Aubertin

The unique nature of rock salt blasting is compared to traditional hard rock practices. Rock salt geomechanical nature is discussed in the context of rock blasting events. A cratering mechanism prevalent in soft rocks is presented and exemplified through a series of single hole blast tests performed in salt deposits.

Feb 1, 2020

By Bruce R. Leland, Steven H. Smith, John D. Paulson

The USDA - Wildlife Services has been removing beaver dams with explosives for over 30 years. This paper will discuss the history of the explosives program, summarize how we've evolved, and highlight our work removing beaver dams in unique locations.

Feb 1, 2020

By Dr. Paul Worsey, Dr. Calvin Konya, Dr. Anthony Konya

Development of methods to calculate presplit blasthole pressures through simplified models, namely the Empirical Model and the Detonation Pressure Model. These models can be used with variations in explosive type and diameter, along with borehole diameter. All models have been validated with test data and shown to have minimal error.

Feb 1, 2020

By PHILIPP HARTLIEB, Peter Schimek, Thomas Seidl, Pablo Segarra, José A. Sanchidrián, Juan Navarro

This paper develops a new Blastability Index to assess hole-to-hole fragmentation in bench blasting based on a new Rock Factor exclusively obtained from drill-monitoring data, that can provide an automatic assessment of rock structure, strength, and waste/ore, the effective energy factor of the explosive and the delay time per blasthole.

Feb 1, 2020

By Ruilin Yang

Kinematic approach of blast modeling refers to using the velocity, strain, or displacement as controlling parameters to model blasting, rather than the stress and the material constitutive relations. The rock stiffness or constitutive relations is very hard or impossible to obtain due to the complexity of the rock mass property.

Feb 1, 2020