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By C. F. Willis

The time is no longer when a man can act as an independent unit; the appreciation of the interdependence of one man upon another has emphasized the importance of the social unit. Epidemics have made us recognize that even a man's health is not distinctly his own to control as he pleases. The physical examination of workmen previous to employment started with an effort to prevent the spread of tuberculosis, for tuberculosis may be detected in its early stages and cured. But it was soon found that many other diseases were detected and the saving of lives made possible. The physical examination does not mean the elimination of the unfit—on that basis it would utterly fail—but rather the measuring of a man's physical fitness and placing the man where he can do the best for himself, his fellow worker, and the company. Industry as a whole cannot expect to live up to the standard of physical examination set for the army, nor should it expect to do so, for in all branches of industry there are types of work that do not require the same amount of endurance as does army work, and the lacing of men with physical limitations in the work for which they are capable permits a higher average of physical fitness for the work requiring physical excellence. Objects of Physical Examination The objects of physical examination are: The early detection of illness, particularly at a time when a full restoration of health is possible; the protection of employees from infection caused by working in contact with contagious diseases; the discovery of a man's physical limitations, in so far as his possibility for rendering good service is concerned; assistance to the safety movement by eliminating association in hazardous occupations with men whose physical condition renders them likely to accident to themselves and others; and the lessening of time lost by sickness. Statistics issued by the United States Department of Labor show that 22.54 per cent. of idleness is caused by sickness, with an average number of 7.71 weeks idle; whereas only 1.66 per cent. is caused by acci-

Jan 1, 1920

By Andrew Peterson

The Maine Department of Transportation offered this challenging design-build project for a new, 12-span, bridge over the Kennebec River in Bath, Maine. This structure would be built to replace the existing Carlton Bridge connecting the village of Bath, Maine to neighboring Woolwich, Maine. The design build team of Flatiron Structures, Inc., and Figg Engineers, Inc., elected to design and build a segmental concrete bridge. Site conditions dictated that this bridge would be supported primarily on deep foundations. Case Foundation Company joined the project team in the winter of 1997 to install twenty-two, eight foot diameter drilled shafts. The drilled shafts were designed with 8' diameter, permanently cased shaft sections and 7.5' diameter rock sockets. Shaft lengths ranged from 20' long near the river's edge to 100' deep in the middle of the river. Rock socket lengths ranged from 12' to 30' deep. Two Osterberg Cell load tests were conducted on production drilled shafts. Figg Engineers utilized the results of the load tests to "fine-tune" the rock socket design during construction of the drilled shafts. Construction of the drilled shafts proved to be very challenging and called on every member of the design-build team to work together throughout the project. One of the most challenging aspects of this project was in the installation of the 8' diameter permanent casing and drilling of the rock sockets. Early in the project, it became apparent that the top of bedrock was broken and unstable. This condition limited the advancement of the permanent casing and the affect of a "seal" at the top of rock socket. As a result, as the rock socket was advanced, loose material spilled into the hole and stopped progress of the socket. In order to resolve this problem, the design-build team developed a redesigned drilled shaft which included the installation of a steel sleeve to seal off the unstable rock formation. Following installation of the sleeve, the rock socket diameter was reduced to 7' diameter and advanced additional length to achieve required design capacity. All drilled shafts were installed with equipment supported on floating barges. Water access, along with the long shaft lengths and very hard bedrock required the use of cranes and drilling equipment that far exceeded the requirements of typical drilled shaft projects. This paper will discuss the relationship between design, construction, and equipment utilization on this challenging design-build project. [ ]

Jan 1, 1999

By P. Somasundaran

Almost a decade has elapsed since the problem of fine particles processing was first discussed at the National Science Foundation workshop in Arden House (Somasundaran and Fuerstenau, 1976). Problems involved in processing fines are as enormous now as they were then. We still lose 20 to 50% of mineral values during the processing of many ores. While the problem's magnitude has remained at as high a level as ever, our perspective on the causes for the difficulties, I believe, has changed. While we do not yet see any grand unified solution to all the problems in this area, I do feel that we are beginning to get an understanding of the basic reasons for the behavior of fines. I would like to share my views on the fundamental reasons for the problems we face. They are based essentially on results obtained during the last few years. A decade ago, I presented the reasons shown in the [Fig. 1] as the causes for the difficulties in separating fines. We have seen the same type of information discussed by others during the years since then. I now believe that these are not the only primary causes. Indeed, they do contribute, but there are other major reasons we ought to recognize. Mass certainly would have its effect, but since microorganisms and even ions can be separated from each other using flotation, provided correct conditions are used. I do not believe that fines 10,000 times bigger suffer fundamentally from their smallness or lightness. Similarly, the surface energy increase cannot be as important a fundamental factor since, theoretically, we should not see significant changes in surface energy until we get down to particles a hundred times finer than we are concerned with. Increase in surface areas, again, cannot be a primary problem except for an increase in reagent consumption. What possibly could be the reasons? I have added these three items to the list in [Fig. 1]: morphology, mineralogy, and surface chemical composition. Differences that I believe are partly responsible for the behavior of mineral fines are those due to alterations in morphology or mineralogy and surface chemical composition with decrease in size.

Jan 1, 1985

A universal grinding circuit model suitable for an arbitrary structure of flowsheet has been suggested. In this model classifiers and mills are described in a most general form. What puts the model in a class by itself is the automatic mass balancing in all streams of the circuit. In order to provide this a special classifier model is adopted. A previously published continuous steady state process model is used as a grinding model. Non-linearity of classifier model leads to a resultant circuit model which is equivalent to a non-linear integral equation. It complicates somewhat calculation algorithm in comparison to that of linear model, but provides a physically meaningful solution.

Jan 1, 1993

By K. J. Shoop

This study investigates the use of a horizontally-baffled column (7.6 cm inside diameter by 344.2 cm high) to reduce the ash content of a high ash bituminous coal. Tests were carried out to determine how the baffled column responded to changes in feed rate, reagent dosage, and feed quality, and to compare its performance with a conventional column installation in an operating plant. In this paper, the results of this investigation will be reviewed and discussed.

Jan 1, 1997

By Ronald M. Fedrick

The microtunneling project for the State of Hawaii's Natural Energy Laboratory (NELH) facility in Kona, Hawaii, was awarded to Nova Group Inc., Napa, California. Nova has developed both microtunnel and deep pile cofferdam experience. Both of which would be required for this project. The project was designed by Makai Ocean Engineering of Honolulu as a continuation of the Ocean Thermal Energy Project (OTEC). The world's first OTEC plant has been successfully operational at NELH since 1982 netting approx 50 kw of usable electric power from a gross generation of 210 kw. A second plant designed to draw 39°F cold water from 3,000 ft below sea level and produce a gross output of 1 mw with a net 500 kw of usable power required 2 - 54 in. finished diameter pipelines. An ongoing problem with earlier offshore pipelines has been the damage to the near-shore pipes within the surf zone. The necessity for a deeper connection between the land based pipe and submerged sea pipeline was obvious. Earlier pipelines had been drilled and shot through the shoreline. This process was only practical at shallow depths. Makai Ocean Engineering and the NELH scientists looked at different methods to get the pipeline through the shoreline at a depth of 80 ft below sea level. Initially, the direction drilling method was proposed as the most potentially practical method. A contract was awarded and various attempts were made to complete a successful

Jan 1, 1995

By L. D. Robbins, M. L. Murphy, A. C. Campbell, L. Murphy

This paper reports on what appears to be the first discovery of prehistoric mica-schist mining in southern 4frica. The mine concerned was found in a location very rich in rock art that is one of the most important archaeological sites in the Kalahari. The authors conclude that the oval pieces of mica schist that were found at the mine site were used by Khoisan peoples to scrape fatty tissue from hides that were to be cured. Radiocarbon datings seem to indicate that such ovals were used for at least 20 000 years.

Jan 1, 1994

By D. C. Dahlin

The Bureau of Mines has investigated podiform chromite deposits in three ultramafic bodies in the Caribou Mountain and lower Kanuti River areas of central Alaska. The investigation, reported in two parts, was done as part of the Bureau's mission to help insure an adequate supply of minerals to meet the Nation's needs. Part I describes an extensive field investigation and mineralogical studies by personnel from the Bureau's Alaska Field Operations Center. This report, part II, describes the mineralogy of 11 samples that were high-graded from surface exposures at 10 sites and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The 11 samples, peridotites and chromitites that consisted of variable amounts of chromite or chromium-bearing spinets, olivine, and serpentine, were beneficiated by grinding and sizing, gravity concentration, and electrodynamic separation. Three high-chromium chromite concentrates, two high-iron chromite concentrates, and one high-aluminum chromite concentrate were produced. Three other concentrates were marginal, and two were submarginal. Chromium recoveries ranged from 54 to 92 pct. These results indicate that the areas may be significant chromium resources. Potential platinum association with the chromite was also investigated. Analysis of these 11 samples indicates that the areas are not good platinum resources.

Jan 1, 1983

By F. F. Roxborough, P. King, E. J. Pedroncelli

This paper describes tests on the performance of a continuous miner in cutting South African coal. Although coal cutting has been investigated extensively overseas, the results have not led to significant changes in machine design because these machines find little difficulty in cutting the softer overseas coals at a fast rate. In general, the results of the tests show that cutting efficiency improves markedly as the depth of cut per revolution of the drum increases, and that the best spacing of picks on the drum is twice the depth of cut. Pick shape is of secon¬dary importance in terms of cutting efficiency, only small differences having been found between the performances of conical- and chisel-shaped tools.

Jan 1, 1981

By E. A. Beck

For a number of years many attempts have been made to use thermit in order to do away with piping in ingots. Some of these attempts were successful, while others did not give the expected results. Nearly every plant had its own method of using the thermit, and no special care was taken to study the results or to find the causes for lack of success. Formerly the principle of the process was to decrease the piping by introducing a can filled with thermit, attached to an iron rod, into the head of the ingot directly after it had been poured. In this case the thermit reaction took place in the upper part of the ingot, and it was thought that through the heat produced the head would keep liquid longer and piping thus be reduced. In other words, the aim was to keep the head of the ingot open by making use of the heat of the thermit reaction, which would thereby give the gases in the steel sufficient time to escape. This result can be attained by the application of a large enough quantity of thermit, but it would not be economical in general practice, and could only he used for high-grade material. Many steel-makers abroad and in this country have had this experience. The Th. Goldschmidt A. G., Germany, has, therefore, made a special study of this question with the cooperation of a well-known steel company, and has worked out a new method for the application of thermit for this purpose. The results obtained have been most satisfactory and reliable, and this process is now used in Germany on a large scale in many prominent steel-works. The thermit is applied in cans, as in former years, but the principle of the process is entirely different. The object of using the thermit is not to heat the steel and keep it liquid,

Jan 1, 1914

At Pasminco Mining's South concentrator. which was commissioned in 1952. an expansion. modernisation and efficiency improvement program commenced in 1986 with a coarse ore stockpile and grinding circuit expansion. the replacement of small flotation cells and the upgrading of reagent mixing and metering equipment. The program continued with the installation of a TDC 3000 based process control system (1988) and concentrate thickeners (1990). By mid-1991 a further grinding expansion and the installation of zinc flotation feed regrind ball mills and zinc recleaner column cells will be complete. leaving the use of ceramic disc fillers and development of process control strategies as probably the remaining major avenues for improved process efficiency at present.

Jan 1, 1991

By Walter M. Small

Austria produced approximately 800 cisterns of 10,000 kg. each (56,000 bbls.) of crude oil of a 0.9428 sp. gr. during 1935. Of this Gosting II well near Zistersdorf, owned by the Erdolproduktions-Gesellschaft m.b.H., produced 86 per cent of the total, averaging a little over 1.8 cisterns, or about 125 bbl., per day. Gosting IVa of the same company was put in production early in December and produced a total of about 70 cisterns (4900 bbl.). Gosting IV was a failure, but a directional hole drilled from the same derrick produced Gosting IVa. Gosting I, a well owned jointly by the company above mentioned and the Raky-Danubia, was deepened late in the year and made about 2800 bbl. of oil at the rate of 70 bbl. per day. Completions during the year were as follows: In the Gosting pool, Gosting IV and IVa, drilled with rotary tools, the latter producing from Sarmat at a depth of 934 meters (3065 ft.); Kronberg I, of European Gas & Electric Co. with cable tools in Flysch at a depth of 566 m. as a dry hole; in the Oberlaa gas pool, one cable-tool well of the same company at a depth of 266 m. as a dry hole and one Fauck-Haiek system well of the Vacuum Oil Co. at a depth of 483 m. as a dry hole; one rotary hole of the European Gas & Electric Co. at Enzersdorf a/d. Fischa plugged and abandoned in Sarmat after a blow out and gas eruption at a depth of 699.5 meters. The status of drilling wells at close of the year is as follows: In the Gosting pool, Erdol Bohr- und Verwertungs G.m.b.H., north of the producing area, was drilling with rotary at 990 m., Raky-Danubia is rigged up to deepen the old Windisch-Baumgarten hole, Rohoel-Gewin-nungs A.G. (Vacuum-Shell combination) rigging up rotary south of the production, and Steinberg-Naphta G.m.b.H. (Musil) was deepened with light rotary to 830 m.; at Enzersdorf a/d. Fischa, the European Gas & Electric Co. E-2 rotary-drilled hole stood at 1533 m. in Miocene waiting

Jan 1, 1936

By Walter M. Small

Austria produced approximately 800 cisterns of 10,000 kg. each (56,000 bbls.) of crude oil of a 0.9428 sp. gr. during 1935. Of this Gosting II well near Zistersdorf, owned by the Erdolproduktions-Gesellschaft m.b.H., produced 86 per cent of the total, averaging a little over 1.8 cisterns, or about 125 bbl., per day. Gosting IVa of the same company was put in production early in December and produced a total of about 70 cisterns (4900 bbl.). Gosting IV was a failure, but a directional hole drilled from the same derrick produced Gosting IVa. Gosting I, a well owned jointly by the company above mentioned and the Raky-Danubia, was deepened late in the year and made about 2800 bbl. of oil at the rate of 70 bbl. per day. Completions during the year were as follows: In the Gosting pool, Gosting IV and IVa, drilled with rotary tools, the latter producing from Sarmat at a depth of 934 meters (3065 ft.); Kronberg I, of European Gas & Electric Co. with cable tools in Flysch at a depth of 566 m. as a dry hole; in the Oberlaa gas pool, one cable-tool well of the same company at a depth of 266 m. as a dry hole and one Fauck-Haiek system well of the Vacuum Oil Co. at a depth of 483 m. as a dry hole; one rotary hole of the European Gas & Electric Co. at Enzersdorf a/d. Fischa plugged and abandoned in Sarmat after a blow out and gas eruption at a depth of 699.5 meters. The status of drilling wells at close of the year is as follows: In the Gosting pool, Erdol Bohr- und Verwertungs G.m.b.H., north of the producing area, was drilling with rotary at 990 m., Raky-Danubia is rigged up to deepen the old Windisch-Baumgarten hole, Rohoel-Gewin-nungs A.G. (Vacuum-Shell combination) rigging up rotary south of the production, and Steinberg-Naphta G.m.b.H. (Musil) was deepened with light rotary to 830 m.; at Enzersdorf a/d. Fischa, the European Gas & Electric Co. E-2 rotary-drilled hole stood at 1533 m. in Miocene waiting

Jan 1, 1936

By S. P. Howell

"Technical statistical study has been made of accidents in the anthracite region of Pennsylvania in which explosives were involved. The data have been taken from the accident reports in the files of the department of mines of Pennsylvania, supplemented by inquiries in the field.This study has disclosed a wealth of information regarding the nature and the cause of accidents that occurred where different means of firing shots of explosives were employed. In the anthracite region shots are fired with fuse, with squibs, and with electricity,Many of the salient features of this accident experience are illustrated in this report of investigations, and a number of recommendations are made to reduce the hazards of each of these three methods of shot firing.Experience seems to demonstrate that, under conditions in the anthracite region, electric firing of shots is substantially the safest method; that accidents wherein fuse is employed are more frequent than accidents in which electric firing is employed; and that the number of accidents when squibs are employed far exceeds those in which either fuse or electric firing is used."

Mar 1, 1930

By Tom Treleaven

The success of any blast is dependent on the accuracy of the blast design and the field controls used on the shot. This point cannot be over emphasized because when the geometry is not measured and/or field controls are not properly implemented, it can often have devastating effects on the final blast results. Thus drilling accuracy, tiont row burden control, explosive confinement, energy distribution, explosive selection, timing and structural geology become critical parameters in the design of successful blasts. Understanding the actual dynamics of the blast and why certain results were achieved is the fast step in optimizing a blast design. As stated by R. Frank Chiappetta, “Of all the blast monitoring systems available today, high speed videography still remains as the best stand alone instrumentation system for blast diagnostics.” Over the past years I have analyzed hundreds of blasts using either high-speed lowcams (500 frames per second) cameras or standard digital (30 frames per second). These analyses confirm, without a doubt, that shot geometry, in combination with structural geology, is the most important factor in overall blast results. Drilling accuracy is the single most important component in efficient blasting. Having equal mass associated with an equivalent energy is the basis in which blasts are designed. When drilling inaccuracy or borehole deviation occurs, not only is the energy unevenly distributed, but the basis of all design calculations becomes invalid. Over the past several years, quarry and mining operations have employed the use of boretracking measuring devices to measure borehole deviation and hole toe locations. In cases of operations using top hammer drills, it was discovered that the amount of deviation was significant and far greater than they believed they had. Set up error, improper drilling techniques and bit wear were some of the contributing factors. Through video anaysis of boretracked blasts, blast results were directly linked to drilling ..accuracy. The comparisons here took into account blast design, energy factors and hole sequencing.

Jan 1, 2000

By R. J. Robbins, D. L. Anderson

A tunnel boring machine has potential use in al- most any type of mining where the access shaft (or adit) is large enough or can be made large enough for its initial entry and where the orebody is of sufficient size to warrant its use. Some time will inevitably be lost in negotiating curves or making lateral moves and moving from level to level. Nevertheless, if the orebody is sufficiently large, advance scheduling can minimize the lost time encountered in such moves. Ideally, a mine will be planned for the use of these machines, thus eliminating access and transport problems. From the viewpoint of time involved, the rate of advance by boring as compared to conventional means is worthy of review. For instance, the Blanco Tunnel, one section of the Bureau of Reclamation's San Juan-Chama Project in southern Colorado, was bored in competent sedimentary rock with the following performance:

Jan 7, 1967

By Shular R. Scudamore

There was a time when heavy-duty apron feeders were built to last almost forever. The machines were heavy and built to maintain certain expected longevity and reliability. Increasing emphasis on return on capital leads to cost-effective designs. Costs can be increased or decreased, depending on customer specifications and the design philosophy of the feeder manufacturer. Specifiers can make important contributions to cost effectiveness. To do so, this article describes what should be known about planning with a supplier for heavy-duty apron feeders. There are several factors that should be considered, including capacity, characteristics of material carried, length, method of feeder loading, degree of lift, hopper opening, pan construction, and type of drive. Today's apron feeders are built in various sizes and with a variety of components to handle heavy, lumpy, or abrasive materials that can ruin lighter feeders. Careful feeder selection is important if it is to provide a controlled feed rate, absorb huge impacts, be used with long hopper openings, and have a relatively low power-perton capacity. Variations in systems and materials demand that each feeder be designed for its application, drawing on a wide range of components. Therefore, certain factors must be considered before final specifications are drawn. Capacity The design and application of an apron feeder is based on how material passes through a given system over the feeder into processing machinery. The processing machinery's capacity governs other equipment and productivity of the flow. From this basic information, related sizes of upstream equipment can be determined. Of these, the apron feeder acts as the "mouth and neck of the bottle." No more will pass than the mouth and neck will accommodate. Everything in the apron feeder design, from dimensions to power, is based on processing machinery. Material Considerations Are Vital Just as the nature of materials to be crushed or screened affects capacity and productivity of a crusher or a grinding mill, so does it affect capacity and performance of a feeder. Lump size must be identified closely so the pan width can be selected to accommodate the maximum lump with room to spare. For example, a lump size of 760 mm (30 in.) indicates a pan width of 1.5 m (60 in.) While two times the maximum lump is considered minimum width, if the maximum lump

Jan 12, 1983

By Francisco Anglade

Dado que la simulación digital es una herramienta auxilar para los ingenieros de procesos -en tanto evalúa la factibilidad de un flowsheet propuesto y predice el efecto de una modificación para un flowsheet existente, su importancia también se extiende también a la evaluación de alternativas para las estrategias de control en los circuitos de la planta. En ese sentido, el presente trabajo señala los beneficios económicos y técnicos obtenidos en la planta San Rafael mediante el empleo de simuladores en los circuitos de molienda, chancado y concentración gravimétrica, los cuales permiten corroborar los cambios efectuados u optimizar los circuitos señalados de forma simple y rápida.

Sep 9, 2007

By John A. Cherry

Groundwater monitoring conducted at an acidic uranium-tailings impoundment in Wyoming and at one in Ontario indicate that at these unlined impoundments situated on unconfined sand aquifers, there exist well-developed plumes of contaminated groundwater. In the literature similar results are reported for three other unconfined aquifers at mill sites in Wyoming. The plumes extend for distances of several hundred to a few thousand metres from the impoundments. They have a zone of low pH beneath and adjacent to the impoundments and a larger zone of near-neutral pH that extends to the outer limits of the plume. The low-pH zones are generally small compared to the neutral-pH zones because the advance rate of the fronts of acidic tailings-derived water is slower than the average velocity of groundwater which controls the advance of the high pH zone. The retardation of the acid fronts is a result of geochemical reactions that cause hydrogen-ion consumption in a slowly-advancing neutralization zone. Within each of the plumes, the low-pH zone has high concentrations of transition metals, heavy metals and radionuclides. In the neutral-pH zones all of the metals and radionuclides occur at significantly lower concentrations and are generally at levels much below those specified in national drinking water standards. An exception at two of the Wyoming sites is uranium, which exists at levels close to the drinking water limit. A second exception is ferrous iron at the Ontario site, which occurs at high concentrations throughout most of the plume. The carbonate alkalinity at this site is much lower than at the Wyoming sites. The field data indicate that even in very permeable aquifers with a low content of silt and clay, there is normally a considerable capacity for acid-front retardation. To take advantage of this capacity to control contaminant movement in the design, operation and decommissioning of tailings impoundments, it is necessary to be able to predict the rate of acid-front movement. This predictive task has two primary components. The first is to identify the important flow paths from the tailings through the groundwater system and the second is to determine the degree of acid-front retardation that will occur as the tailings-derived water moves along these flow paths. Relative to these two tasks determination of the effects of hydrodynamic dispersion is generally of lesser importance and simple approximations that do not involve field or laboratory tests are probably adequate. In order to effectively apply the acid neutralization concept to the prediction of subsurface contaminant migration at uranium-mill tailings, improved representations of hydrogeochemical behavior of iron and aluminum in the neutralization zone and of the consumption of hydrogen ions through reactions with carbonate and aluminum-silicate minerals are required. Along with the hydrogen ions contained in the tailings water the ferrous iron represents a large potential source of acid but the extent to which ferrous iron converts to ferric iron to produce acid is problematic. Detailed hydrogeochemical evaluation of existing contaminant plumes and the performance of laboratory experiments under appropriate redox conditions ore prerequisites for the improvement of predictive models. However, the existing field and laboratory data provide a basis for preliminary predictions of contaminant migration from acidic uranium tailings impoundments.

Jan 1, 1982

By A Gustafson, D Johansson, K Jonsson

The underground mining process, from in situ characteristics of the unmined rock mass to the final mill product with fully liberated minerals, consists of a chain of unit operations. Some of them influence fragmentation while fragmentation impacts others. From a production point of view, fragmentation is a key parameter for the proper functioning of many unit operations and affects total production; it influences the ability to load, haul and crush the rock later in the process. Fragmentation varies because of rock mass strength, the presence of joints, the chosen explosive, specific charge (kg/m3) and quality of drill holes. The efficiency and result of unit operations such as drilling, blasting, loading and crushing depend on the rock properties, which vary throughout a mine. Generally speaking, operations are not well adapted to the actual rock properties, leading to a non-optimised flow in production. This paper presents the initial part of a project that will build knowledge on the impact of fragmentation on each step of the production chain in an underground mine. It identifies the key parameters of fragmentation, which influence the overall energy consumption and productivity in a mining operation through interviews, mine visits and a literature review. In the subsequent stages of the project, a number of field tests in the case study mine will address important segments of the production process where fragmentation is a major obstacle to improvements. Optimising the entire process, rather than isolated unit operations, will lead to increased productivity, decreased amount of interruptions and lower energy consumption.CITATION:Gustafson, A, Jonsson, K, Johansson, D and Schunnesson, H, 2016. From face to surface – a fragmentation study, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 555–562 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016