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By R. K. Sinha, B. S. Choudhary, Desh Deepak, A. K. Mishra, Hemant Agrawal, Shankar Kumar

There are several methods (empirical, statistical, and machine learning tools) to calculate blast-induced ground vibration. Still, due to complications in the blasting procedure, under varying blasting loads and strata conditions, it is not easy to predict and simulate blast vibration precisely. Therefore, a study was conducted to simulate the field blast data in Ansys software using explicit dynamics. For this study, monitoring of ground vibration for 20 single hole blasts was carried out. The density of emulsion explosives was in the range of 0.9 to 1.15 g/cc. In the laboratory, rock properties were determined from the rock sample collected from the mine site before blasting. The in-hole velocity of detonation (VoD) and the density of the emulsion explosive were also determined. These parameters were used for numerical analysis to know the ground vibrations at specified points. The results of ground vibration predicted by the model are validated using field data.

By JOHN R. SUMAN

IT appears now that the conflict with the totalitarian states will be a long-drawn-out struggle. The course of this war up to now indicates that this may well be the first major conflict where man power has not been the vital and determining factor. Mechanized warfare has made it possible for relatively small, well-equipped groups to outmaneuver and defeat large armies which lack the necessary modern equipment. Under these circumstances, ultimate victory becomes a matter of resources and productive ability. The important question is not how many soldiers can he put into the field, but the volume and speed in producing the armaments essential to ensure a victory. The resources available to the opposing nations and the efficiency of their systems of enterprise and production will be primary factors in determining the ultimate outcome. Germany had a head start of eight years in the armament race, and it is not easy to overcome such an advantage overnight.

Jan 1, 1942

By Betty L. Gibbs

Microcomputers are becoming more convenient to use at all levels of the business world, including the mining industry and mine offices. The state of the mining industry requires that we become more productive and innovative in our analysis of deposits and operations. With the help of computers, examination of options to increase productivity can be performed quickly and inexpensively. Effective use of the computer for designing underground workings combines the calculation power and speed of a computer with the technical expertise and judgment of the engineer. Computer programs can perform calculations in minutes that could take an engineer several months. The engineer must be on guard when using the computer for any calculation because it is very easy to assume the results produced by a computer program are always correct. The computer is a sophisticated calculator but cannot recognize logical errors nor transposition of numbers. Also some intuitive or obvious decisions made by an engineer are difficult or impossible to program effectively.

Jan 1, 1987

By I. N. Gridasov, V. V. Khromov, R. I. Ismagilov

"Over 50 mln.tonne is the average annual output of oxidized ferruginous quartzites typically containing Fe38-42% mined in Mikhailovskoye ore field. The most promising and cost-effective way to expand concentrate production maintaining current output of magnetite is processing of oxidized ferruginous quartzites (hereinafter referred to as OFQ) mined as a by-product in Mikhailovsky open pit mine. However lack of proven and efficient concentration and agglomeration process applicable to OFQ and insufficient data for feasibility evaluation of OFQ processing encumbered full-scale addressing of this challenge. Based on outcomes of multiple various studies a process of OFQ flotation was designed by MC Metalloinvest LLC and PJSC Mikhailovsky GOK engineers. Comparative lab-scale testwork have proven performance and production advantages of flotation against magnetic separation feat. flotation and combined concentration method. Lab-scale flotation enabled production of concentrate with average Fe66.6% and SiO22.06% grade. Geologic and production contouring of OFQ deposited in Mikhailovskoye ore field has been carried out to collect necessary data for feasibility study incl. cost and profit estimation. As a result processing and production properties of over 3,500 samples have been analyzed which is characteristic of every direction and level of prospective ore mining within Mikhailovskoye ore field up to year 2032. Following work has been done based on geologic and production contouring of OFQ: – natural typification of ores and production (processing) grades of OFQ, determination of average mineral composition; – correlation analysis of interrelation between OFQ mineral composition and processing features thereof for overall bulk of samples as well as for individual data blocks related to various directions of open pit mine; – OFQ classification with account of defined mineral composition and processing features. Total Fe weight content in chamber product of flotation (known as concentrating ability in flotation) was applied as a major differentiating factor for processing grade classification of OFQ. Three processing grades of oxidized ferruginous quartzites were established as a result of flotation tests run to determine concentrating ability, i.e. – hard concentrated OFQ (TO) – below Fe65%; – mean concentrated OFQ (SO) – Fe65-67%; – easy concentrated OFQ (LO) – over Fe67%. Outcome of this work provided initial data for feasibility study and cost-profit evaluation of medium-term industrial-scale processing of OFQ deposited in Mikhailovskoye ore field."

Jan 1, 2018

By Brian E. Perrine

Underground mining requires a variety of specialized equipment. With ever-changing mining conditions and methods, some mines have had to resort to purchasing existing industrial equipment and adapting it for underground use. Since this equipment is not made for underground mining or their specific task, the result is often lost time, money, and sometimes an unsafe working condition. One such application is the setting of a CAN. A CAN is a type of cylindrical secondary roof support made from a cement composite and encased in steel. The CAN has become popular because of its simple one-piece design that can handle heaving and sagging better than other available designs. ?Because of this exceptional ability to sustain load through extended convergence and displacement, the CAN is one of the most robust and stable standing supports in use today.?It also promotes better air flow due to the size and shape of the CAN. CAN size and weight have increased over time to handle more difficult mining conditions. Significant down time and inefficiencies with existing CAN setting machines at Twentymile Coal were directly due to the item in use not being designed to be task-specific. They were undersized with very limited movement. The miners had to take extra steps and precautions when setting CANs. Maintenance delays were significant. Twentymile Coal Company realized that they required a safer, more reliable and more efficient machine to handle and set CANs, and looked for a partner to develop a new design-specific machine. They worked jointly with J.H. Fletcher® engineering and sales to design and manufacture a machine specifically made for setting CANs. The objective was to produce a machine that would handle the conditions and methods that the mine required for setting CANs during longwall retreat. The resulting design had to be safe, stable, have a wide range of motion, be ergonomic, simple to use, and easy to maintain. The machine also had to improve efficiency. The resulting machine has been operating for approximately one year at Twentymile Coal and has been proven to improve safety, reliability, and efficiency. In conclusion, with the task-specific CAN Manipulator, the mine is able to better plan daily tasks with the knowledge that the machine will be available throughout a shift, and the employees will be safer because of the machine?s ergonomics, stability and safety. This has resulted in better productivity and a safer environment.

Jan 1, 2013

The regulations governing the filing of claims under the War Minerals Relief Act have been amended so as to allow claimants to file a brief with the questionnaire. It has been decided that hearings will be conducted by the War Minerals Relief Commission when good reason for such action can he shown. When justified, the Commission will conduct the hearing at a point easy of access from the mining district concerned. Applications for relief are beginning to reach the Commission in considerable volume. Thirty claims have been filed in such condition as has permitted of their formal filing with the Commission. Many others have been returned with instructions as to the information required and the procedure it is necessary to follow.' An effort was made to induce the Secretary of the Interior to open a Pacific Coast branch office of the War Minerals Relief Commission; this he has declined to do, claiming that it is impracticable to divide the work.

Jan 5, 1919

By M. McChesney

Modern materials for underground support* by M. McChesney The properties required of a support material for underground tunnels are discussed and, because concrete is both economical and easy to apply, a number of new reinforcing materials for concrete are examined with particular reference to these properties. From about thirty tests on different types of reinforced concrete, it is concluded that the addition of polymer to a concrete does not seem to influence the concrete's post-failure behaviour, and the on'y benefit to be achieved by this addition is to increase its flexibility (or to decrease it, depending on the polymer). Steel fibres tend to increase both the strength and stiffness of the concrete, but polypropylene fibres, although having definite loadcarrying capacities, provide non-stable failure, also known as brittle failure. The best result was obtained for concrete reinforced with steel wire: the post-cracking strength was very good and was maintained for a considerable deformation.

Jan 12, 1976

By Betty L. Gibbs

Mine planning and scheduling done with computer programs is possible only after extensive work has been completed to define the geologic extent of an ore body and an overall mine design. Mine planning methodology on computer can vary from computerized engineering tasks through systems which completely optimize a plan with little input from an engineer during the actual scheduling process. However, a strong emphasis is placed on producing practical mining sequences which may be "best" rather than "optimum". This section offers several viewpoints on the planning process using computers. Interactive planning and scheduling systems are attractive for many companies because they are easy for engineers to understand, and the results are acceptable. The engineer develops an open pit mine sequence by trial and error using interactive graphics. The results of this approach can usually be improved. A computer program can help an engineer make many trials in a short time period and provide a higher level of confidence that a "best" plan has been generated.

Jan 1, 1989

A career in the mining industry is both challenging and rewarding but comes with some unique complications. Few other industries have such a far reaching effect on individualsÆ lifestyles. Furthermore, few people working within the resource sector could say their job has had no effect on their lifestyle. Mineral deposits in Australia seem to exist predominantly in remote locations like Telfer, Mount Isa and Olympic Dam. With this comes a choice for young professionals; one that is not easy to make, with either alternative often having its pitfalls. This remote nature usually requires professionals (especially graduates and juniors) to choose between a fly-in, fly-out location or relocation to a remote town with less facilities (and some may argue attractions) than their coastal cousins. The challenge for young professionals is to pursue a career that will satisfy their professional goals while developing and maintaining away of life that is emotionally fulfilling.

Jan 1, 2005

By John M. Rapkoch

In the continuing search for copper matte converting methods, commercially available and feasible choices remain Peirce-Smith Converters, Hoboken Converters, Mitsubishi Converting, Ausmelt converting, and Outokumpu/Kennecott Solid Matte Oxygen Converting (?Flash Converting?). While each alternative improves on Peirce-Smith Converters? limited fugitive gas capturing capability, the Peirce-Smith Converter is relatively easy and economic to operate and has an unmatched ability to accept valuable but difficult-to-handle material such as scrap anodes and purchased scrap copper. Recent experience with designing, building, and starting up an ISASMELT facility, applied in primary smelting of copper concentrates, has led the authors to speculate on how suitable the ISASMELT process would be for copper converting, given its low fugitive gas release and its ability to accept a variety of feed types. This paper reviews the potential metallurgical challenges posed by converting copper matte in an ISASMELT vessel and considers possible engineering and design challenges posed by the inclusion of this technology into a new or refurbished copper smelter.

Jan 1, 2006

By Bert Bahnson

As farms decrease and subdivisions increase there is a continuing demand for easy and safe silo removal. A few years ago I attended one of the Omni istribution explosive classes and was impressed by a product designed by Omni owner Bill Nixon called the Omni Breach. Its original purpose and main current use is law enforcement; specifically door breaching and tactical operations, with most of the force coming from water using a minimal amount of explosive component. I experimented with various charge strengths on concrete and found that it can be easily shattered with little flyrock or airblast. A neighbor of mine had an old silo within a foot of a barn that he was rebuilding and inquired about its removal. His property was sandwiched between an elementary school and Interstate 40, so I told him that I would do some test shots and if the results proved satisfactory, I would take the job for free to test the following theory.

Jan 1, 2006

By William P. Blake

Travelers in the desert regions of the southwestern portion of United States, especially along the valley of the Colorado of the West, can hardly fail to note that most of the rocky outcrope of the harder rocks have a uniform prevailing blackness of the surface, in strong contrast with the normal color of the interior of the rock when freshly broken. For example, the granitic or gneissic rocks of Pilot Knob, below Yuma, are blackened beyond easy recognition. So also rocks upon the lower Mojave in California are so thoroughly blackened, as if painted, that ordinary gneiss can scarcely be recognized without breaking it so as to show the interior color and structure. The discoloration is not confined to the rocky outcrops in place, but is found upon boulders and upon the loose rounded pebbles which strew the surface of the mesas along the Colorado river. These fragmentary rocks partake of the general blackening.

Jan 1, 1905

By S. G. Galbraith

We have used the principles of supramolecular chemistry to develop reagents to transport metal salts. These reagents have separated charged "compartments" which recognize a metal cation and its attendant anion(s). They are easy to manufacture as they are structurally related to the commercial hydroxy-oxime extractants for copper. Efficient protocols for loading and stripping of these extractants depend on the novel feature that they bind the metal salt in a zwitterionic form of the ligand. Transfer of the phenolic protons to the pendant amines generates the charged "compartments" to accommodate the metal cation and its attendant anion(s). This paper focuses on how these types of reagent can be used to recover base metals from sulfate and chloride media in flowsheets in which solvent extraction effects separation and concentration operations, interfacing between conventional leach and electrowin/reduction processes. Work on the development of reagents that have high selectivity for metal chloride/sulfate transport, convenient stripping protocols and appropriate hydrolytic stability will be described.

Jan 1, 2003

By B. R. T. Simoneit

The conversion of organic matter to petroleum by hydrothermal activity is an easy process, occurring in nature in many types of environments. Geologically immature organic matter of marine sediments is being altered by this process in Guaymas Basin (Gulf of California), Escanaba Trough and Middle Valley (northeast Pacific), Bransfield Strait (Antarctica), and Atlantis 11 and Kebrit Deeps (Red Sea). Contemporary organic detritus and viable microorganisms are also converted in part to petroleum-like products by the same process when present to become entrained, as for example on the East Pacific Rise at 13o N and 21o N and on the mid-Atlantic Ridge at 26oN. The hydrocarbon products (methane to asphalt) generated in all these areas have been elucidated in terms of composition, organic matter sources, and analogy to reservoir petroleum. This petroleum represents a major input of carbon to the primary chemosynthetic productivity of hydrothermal vent systems and may be important to interactions with metals in hydrothermal ore formation.

Jan 1, 1991

By D. S. Newton

Introduction Historically the production of zinc dust has been based upon residual and secondary zinc. Using horizontal retorts filled with diecasting scrap, galvanizers drosses and sweater billets, dust has been produced by condensation into static condensers on a 24 hour cycle. Although fairly flexible as regards input materials the process is not amenable to close control of the product, is labour intensive and unless carefully run can cause fume problems. With a steadily increasing demand for zinc dust of consistent properties and higher quality there is a demand for an improved method of manufacture in which dust can be produced continuously and which is capable of close control thus ensuring a minimum amount of oversize or unsaleable material. The Process in use in the works of Imperial Smelting Corporation (Alloys) Ltd. in England, and in Canada and Holland, satisfies the criteria stated above, and has proved to be easy to control with a minimum labour demand.

Jan 1, 1970

By John Durkin, Steven Wirch, Fred N. Kissell, Steven Ruggieri

The Bureau of Mines has developed two expert systems to give advice on coal mine dust control, one for continuous miner sections, and another for longwalls. Prototype versions have been evaluated by coal operators and MSHA. Both systems query the user as to the nature and extent of the dust control problem. Typical questions asked deal with matters such as cutting sequence, current dust standards and characteristics of current dust control techniques. Advice given by the system generally does not focus on a single issue, but may suggest a variety of approaches consistent with the ability of the operator to practically implement what is suggested. Both were written using expert system development software called Insight 2+. The advantages of Insight 2+ for the user are: low cost, IBM-PC compatibility, and the fact that little prior experience with computers is required. For the developer, Insight offers an easy to use production rule language and goal driven structure as well as a wide variety of capabilities.

Jan 1, 1987

By A. K. Kyllo

The use of Composite Furnace Module cooling systems has been shown to give improved refractory performance in a number of above bath locations in WMC flash furnaces. To test the behaviour of modules in contact with a melt, a set of instrumented modules have been installed in the reaction shaft of a. nickel flash furnace. The location was chosen to provide a suitably harsh environment to ensure rigorous testing, while still allowing relatively easy access for module installation. The modules were continuously monitored to provide information on the module performance, as well as the temperature in the shaft itself. The shaft temperature showed significant transient behaviour, which resulted in heat fluxes through the modules ranging from 10 to 92 kW m-2. The modules were capable of handling the highest heat flux with no risk of the coolant boiling. This paper details the design and operation of the modules over a period of seven weeks.

Jan 1, 1999

Provide the mining industry with an easy-to-use means of accurately predicting surface subsidence caused by longwall mining in the northern Appalachian Coal Basin. Approach The Bureau of Mines developed a subsidence prediction model using the novel approach of a variable subsidence coefficient. This approach had to be used because of the resistant strata types which commonly occur within the relatively thin overburden material typical in northern Appalachia. Such resistant strata precluded the use of the popular European methods that assume homogeneous overburden or overburden behaving as homogeneous from a subsidence point of view. The model is available in a BASIC computer program for use on most personal computers. The user has the options of obtaining individual subsidence calculations or may choose to develop a subsidence profile using an average overburden value. The program output can be generated in graphic or tabular form showing the location of the surface point with respect to the longwall panel edge, overburden depth, and the subsidence value.

Jan 1, 1986

By O. Bilharz

The rules laid down by Peter von Rittinger in his classic Lehrbuch der Aufbereitungskunde (Berlin, 1867, p. 513) concerning the designing of dressing-works still possess authority for such works and their operation. Nevertheless, some modifications and additions suggested by practice may be of value at the present time. Rittinger says: "I. Choose the apparatus and machines which can be, under the existing con-' ditions, easily constructed and kept in running order!' This rule contemplates the construction of apparatus (mostly of wood) on the spot, with the command of good sbops and especially of good workmen in wood. But in many cases, particularly for the sake of a prompt supply, the construction of apparatus is now left to special manufactories, which pay more attention in the choice of materials to durability and strength than to easy manipulation and erection. Nevertheless, here,as in many other instances, simplicity of construction and solidity of execution are to be recommended. Especially important is the convenient and cheap replaceability of

Jan 1, 1894

To provide a method for locating trapped miners promptly and accurately. The Approach: Develop a wireless emergency system that is intrinsically safe, compact, easy to operate, reliable, sturdy, and economical. How It Works: A (one transmitter has been developed under Bureau of Mines contracts. The transmitter weighs only a few ounces, is powered by a cap lamp battery, arid can be carried on the miner's belt. A compact loop antenna, which could either be carried by the miner or strategically located in the mine, is used to generate a magnetic field that is sensed by a mobile receiver on the surface. When needed, the antenna is deployed to form a single loop. In mines where the overburden is less than 600 feet, a loop of No. 19 wire approximately 30 feet in circumference is normally adequate. This antenna weighs less than one half pound. In deeper mines, a heavier wire and bigger loop is required; a No. 10 wire deployed around a pillar has been used.

Jan 1, 1974