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By Akira Tsune, Shingo Sugimoto, Tadayuki Ishiyama, Nadao Saito, Masatsugu Okazaki

"The Deep Ocean Resources Development Co. Ltd. (DORD) of Japan signed a 15-years contract with the International Seabed Authority for exploration of polymetallic nodule in a 75,000 km2 area, consisting of West and East Areas in the Clarion and Clipperton Fracture Zone in 2001. The exploration work is now concentrated in resource estimation of the first generation of mining area, the High Abundance Area.A detail survey of the Model Area, set in the High Abundance Area, was conducted using AUV (Autonomous Underwater Vehicle) equipped with MBES (Multi-Beam Echo Sounder), SSS (Side Scan Sonar), Sub-Bottom Profiler (SBP) and still camera. The seafloor topographic map based on 1 m grid data was produced in an area of approximately 80 km2 (Figure 1). Photographs, continuously covering the seafloor taken by AUV along two west-east trending traverse lines, together with detail seafloor topographic map produced from MBES give an excellent opportunity to observe distribution manner of pollymetalic nodule related to topographic features. This helps to understand more accurate resources estimation of a whole area of the High abundance Area. Furthermore, information of micro-topography gives ideas for conducting ore collecting operation and designing ore collector."

Sep 1, 2014

By Pengfei Wang, Guorui Feng

"With the depletion of easily minable coal seams, less favorable reserves under adverse conditions have to be mined out to meet the market demand. Due to several historical reasons, a large amount of remnant coal was left unrecovered. One such case history occurs with the remnant rectangular stripe coal pillars using partial extraction method at Guandi Coal Mine, Shanxi Province, China. The challenge that the coal mine is facing is that there is an ultra-close coal seam right under it, with an only 0.8 to 1.5 m sandstone dirt band in between the two. The simulation study was carried out to investigate the simultaneous recovery of upper remnant coal pillars while mining the ultra-close lower panel using longwall top coal caving (LTCC). The remnant coal pillar was induced to cave in as top coal in LTCC system. Physical modelling shows that the coal pillars are the abutments of the stress arch structure formed within the overburden strata. The stability of overhanging roof strata highly depends on the stability of the remnant coal pillars. The gob development (roof strata cave-in) is intermittent with the cave-in of these coal pillars and the sandstone dirt band. FLAC3D numerical modelling shows that the multiple seam interaction has a significant influence on mining-induced stress environment for mining of lower panel. The pattern of the stress evolution on the coal pillars with the advance of the lower working face was found. This demonstrates that the stress relief of a remnant coal pillar enhances the caveability of the pillars and sandstone dirt band below them.INTRODUCTIONChina is one of the world’s coal-rich countries. Coal has played a significant role in the growth of China’s economy. Coal reserves have been mined commercially in China for over one hundred years. The demand for coal in China is still going to grow at a relatively high rate (BP Energy Outlook, 2019). Long-term large-scale and intensive coal mining activities have created tension between increased demand and limited resources (Bai et al., 2018). Easily minable coal seams such as sub-horizontal, tabular, and laterally extensive coal seams are being depleted, and therefore the remaining reserves are becoming less favorable. However, in many situations, the coal reserves under adverse conditions have to be mined out to meet the market demand for energy.Due to sedimentary environments and geological conditions, many coal seams are interspersed with sedimentary bands, or partings both within an individual seam and between seams. These bands and partings lead to appearance of ultra-close coal seams, as well as giving rise to considerable variation in their structural and mechanical properties (Ghabraie and Ren, 2016). Difficulties are encountered in the mining of such coal seams. If ultra-close coal seams are mined sequentially, that requires the design of a mining system for each individual coal seam; also, a large number of gateroads have to be excavated, which is not a high-efficiency option. If ultra-close coal seams are mined at a great mining height at once, for instance, using longwall top coal caving—a longwall mining method that is widely used in China for the mining of ultra-thick coal seams—then the location and characteristics of the band would have a significant influence on success of their extraction."

Jan 1, 2019

By Thomas N. Walthier

Exploration is the systematically financed and technically oriented search for mineral wealth. Almost all established mining companies have an exploration department. The size of a company's search varies over the years as the company's profits, or the corporate philosophy change. While the established mining companies have exploration departments, they are also alert to acquiring discoveries made by others -- especially by prospectors and small companies without the resources to develop their find. The emphasis in some large companies stresses self-generated discoveries while others rely heavily on acquisitions; again, over the years the emphasis may alternate. In the last analysis, essentially all new mineral wealth was found through someone's exploration effort. Before we discuss how exploration is financed, it will be informative to analyze how discoveries have been made and by whom. Recently, the author conducted a survey of randomly selected major mining companies to answer these questions. Most companies responded and many went to considerable effort to give complete and detailed answers. I thank all for their help and cooperation. The questionnaire is attached as Appendix I. Appendix II is a list of the 400 companies that replied in a complete enough manner and format to be analyzed here. The results of the questionnaire are given in Table 1. Over 57% of the new orebodies acquired by 40 major mining companies during the past quarter of a century were generated

Jan 1, 1977

By M. P. McArthur

General mining practices at W. R. Grace's Bonny Lake mine are much the same as those used in open pit phosphate mines in Central Florida, except for the difference in the depth of the overburden which introduces many variations, From 1945 to 1961 the mining at Bonny Lake has been from an area in which the overburden averages from 55 to 60 feet and in several locations exceeded 65 feet. The matrix thickness will average 15 to 18 feet for the areas mined. As you can see from the above depths a total hole depth will average from 70 to 75 feet.

Jan 1, 1962

By P. R. Dugan

Sulfur removal from high sulfur coal has several objectives including: a) reduction of the atmospheric load that contributes to the problem of acid precipitation; b) reduction of ash, which contributes to decreased energy transfer in boilers, as well as ash disposal; and c) alleviation of the social and economic dislocations reluted to uneven geographical distribution of sulfur in coal reserves. Cost in relation to the value of refined coal will govern the development of an emerging coal refining industry. Estimation of the premium paid by power companies for coal with a low sulfur content is a good estimate of the value that will be added as the result of refining. Estimates of premiums paid in 1984 are $28.65/t ($26 per st) for reduction of total sulfur from 3’% to 1% S and greater than $28.65/t ($26 per st) for removal below 1% sulfur.

Jan 8, 1987

By D. Bessinger, J. Nell

The electrical conductivity of rutile was optimised as a function of time, temperature and gas composition. These optimised conditions were used to treat rutile/zircon feed prep concentrate samples from a South African heavy minerals producer, prior to electrostatic separation. Enhanced separation between rutile and zircon was obtained when compared to untreated samples. Samples treated in a hydrogen atmosphere and cooled in nitrogen showed the best separation when passed through a high tension electrostatic separator using conditions of high sample temperature and high relative humidity.

Jan 1, 2005

By Russel Delmar

Construction of Ontario Power Generation?s 12.8-m diameter, 10.4-km long water diversion tunnel in Niagara Falls, Ontario, is underway. The tunnel is being excavated by means of a 14.44-m diameter open gripper Tunnel Boring Machine. The tunnel lining is constructed as a two-pass system with the initial lining consisting of rock bolts, mesh, steel channels or ribs, and shotcrete, and the final lining consisting of pre-stressed cast-in-place concrete with a waterproof membrane. This paper describes salient design and construction aspects as follows: ? Regional and Site Geology ? Tunnel Layout and Design ? TBM Tunnelling and Cast-in-place Concrete Lining Construction

Jan 1, 2008

Grouting is mainly used to improve mechanical properties or decrease the permeability of rock mass around civil and mining projects. The purpose of this paper is to present the most effective factors on grout penetration depth in rock mass. Such factors are essential for reliable estimation of the grout penetration depth and the expense for cement take of any grouting project. In this paper, about 50 different types of the relations presented so far by various researchers to estimate the depth of penetration in fractured rock were studied. The effective factors are classified to rock mass properties, grout properties, and operational factors. Results show that firstly, the discontinuities aperture and Lugeon value are respectively the most investigated factors of rock mass properties influencing on penetration depth. Secondly, the yielding stress, viscosity, and density of grout are the most effective factors of grout properties. Finally, grouting pressure has an intense effect among other operational factors. The investigations were also verified in Siah Bishe dam case study. Keyword: grout penetration depth, rock mass properties, grout properties, operational factors.

Feb 27, 2013

By Harold F. Yde

Hydraulic tailings fill in the Butte deep level mines was based upon studies made in 1958 by the Anaconda Company Mining Research Department, which published Bulletin No. 35, entitled "Hydraulic Stope Filling". Since then, many things have changed. At the time of the Research Departments study, dry mine tailings were hauled by rail cars from the Anaconda tailings ponds, twenty-five miles distant, to the underground mines' tailings fill plants at the Leonard Anselmo, and Mt. Con Mines. Now, with the installation of the new Weed Concentrator in Butte, tailings is delivered by pipeline to a cyclone at the Kelley Shaft, and stope filling has become more highly automated and streamlined. Presently, mill tailings at approximately thirty percent solids by weight, is pumped from the concentrator, eight thousand feet horizontally and upward, to the Kelley Fill Plant, where they are dewatered and deslimed by three Krebs Model D20B Cyclones, which discharge the material into the cased and grouted mine delivery bore holes at desired densities up to seventy percent solids. The vertical boreholes and four-inch rubber lined Victaulic pipe carry the material downward to horizontal distribution lines, which in turn tap into the stops-filling, three inch, unlined steel Victaulic pipelines. The slurry may travel several thousand feet before it finally discharges into the stope, where it lends support to the mined-out area.

Jan 1, 1969

Sinter mixes of three iron ore types were prepared with a range of water contents in a laboratory investigation. The mean diameter of the granulated mixes and the void fraction of beds of the mixes were determined experimentally. Pressure drop measurements over a range of flow rates were made in a laboratory permeameter with pressure tappings at several depths in the bed. The Ergun equation was applied to the results to determine the shape factor of the granulated mixes. The pressure readings down the bed were used to estimate the local void fraction in the bed using the Ergun equation and the calculated granule shape factors and it was found that there was a decrease in void fraction with depth in the bed. The significance of this and the variation of the shape factor values with the amount of water used for granulation is discussed in relation to the strength of granules of the sinter mixes.

Jan 1, 1984

By Miguel Carrera, Jose Arnal, Julian Ortiz, Maarten Haest, Fouad Faraj

ShovelSense is a complete solution for bulk ore sorting at the mine face that combines robust shovel bucket mounted X-ray fluorescence sensors, with real-time material classification, fleet management integration and supporting cloud-based data infrastructure, to ensure each truck always goes to the right destination. Correct truck destinations are a challenge in many current mining settings because the material classification of a truck, which is the key input into the truck destination, is often based on estimates at block resolution (~20x20x15m), with limited adjustment for blast movement and mixing. In this contribution, we present a geostatistical, data driven approach to estimate the potential value of bulk ore sorting at the mine-face for seven open pit mines. The approach is premised on the assumption that truck loads within blocks follow a simple gamma distribution. Standard ore control data from the seven mines have been used to estimate the potential bulk sorting value at these operations and ShovelSense-integrated dispatch datasets have been used to validate these estimates for specific benches on which ShovelSense operated. ShovelSense results validate the ore control data-based value predictions and show how at mine-face bulk ore sorting value varies between distinct deposit types. In general, deposit types that have higher bulk ore grade contrasts, display more potential ShovelSense value. The manuscript concludes with the limitations and opportunities of applying the proposed value estimation approach to evaluate at mine-face bulk ore sorting opportunities for open pit operations.

Jun 25, 2023

By Edwin B. Wilson

The purpose of the panel's examination of coal mining research and development is to explore how the various groups that make up this research community might work together more efficiently and be more productive. The community, as defined here, includes federal and state governments, coal producers, manufacturers, unions, universities, and industry sponsored research organizations. The framework chosen for these discussions consists of brief presentations by the panel members on their views of the proper role and function of the group they represent. The panel members were also asked to highlight the economic, technical and institutional constraints that affect the performance of research and development and the use of the results. Following these presentations, a number of prepared questions will be discussed by the panel, and audience participation is invited. These questions were given several weeks ago to the panel members for their study. Before proceeding with the panel member reports, a brief review of the importance of R&D to the coal mining industry would be helpful to setting the stage for a constructive dialogue. It is appropriate to begin this review by mentioning that there is complete agreement among the research community that the major goals are: Improve health and safety Protect the environment Increase capital and labor productivity Increase resource recovery Since the basic functions of the academic, industrial and government sectors are different, we should expect that the research and development objectives and priorities, roles and responsibilities under each major goal will be different for each research group. The differences do not represent problem areas. However, problems will arise if the objectives are not properly interfaced at the appropriate time. The consequences of railing to understand the need for integrated programs will be the classic result, best described by the phrase --"a technical success but a commercial failure."

Jan 1, 1978

By Chris Roos

The mining industry has made strides in planning for operations to be safe for the workforce and public, to protect the natural environment, and to maximize value for shareholders. However, many of the techniques used to accomplish these goals are based on estimated models of mineral content, production efficiency, and economic performance. The industry has begun to recognize the need for understanding the uncertainty in these models, how it affects their decisions, and what the potential impacts are for each project. The challenge has become how technical professionals can effectively communicate the impact of this uncertainty and its importance to both technical and non-technical audiences. This paper presents mining engineers (and other technical professionals) with traditional and modern principles of data visualization and technical communication that can assist with communicating the effects of uncertainty in the mine planning process.

Jun 25, 2023

By R. D. Hagni, P. A. Shivdasan

Cathodoluminescence microscopy (CLM) is uniquely applicable to the study of carbonatite-related fluorspar ore deposits. The mineralogy of the carbonatites, sodic and potassic fenites, marbles, quartzites, and fluorite ores are readily determined and characterized. Calcite, dolomite, apatite, fluorite were deposited dominantly under high temperature conditions and they exhibit strong cathodoluminescence (CL). Three types of carbonatites have been recognized at the Okorusu, Namibia carbonatite complex and fluorspar mines by field mapping and laboratory CLM. The main carbonatite intrusion is fine grained and consists mainly of calcite. A later phase of pegmatitic carbonatite consists of calcite, magnetite, Fe-rich pyroxene, apatite, and pyrochlore. Pyroxene carbonatites were recognized mainly through their study by CLM.

Jan 1, 2001

By R. Mensah-Biney

The NC State University Minerals Research Laboratory (MRL) and Waste Reduction Partners (WRP) of the Land of Sky Regional Council joined efforts in 2000 to initiate a technically sound and practical program for the management of high-volume coal combustion by-products (CCBs) in North Carolina. The accumulation of CCBs from coal burning boilers throughout the state of North Carolina posed a substantial storage problem, and the area was overripe for an effective management program, which would be environmentally sustainable. In particular, the public utility generators had filled storage ponds on their properties, and the storage overload had grown to critical proportions. Much the same situation existed for paper mill biosolids, which were stored on site in landfill cells along with daily output of CCBs from the mill boilers. A conversion process via the patented pyro-process12 (US Patent No. 5,342,442) to produce synthetic light weight aggregates (LWA) from CCBs and paper mill sludge was conceived to process large quantities of both these waste materials. MRL and WRP initiated and formed a consortium that brought together academia, private industry and state agencies to evaluate the production of LWA by the pyro-process. The industry partners included representatives from the power companies, industrial ash generators, expediters for coal ash products, as well as concrete block manufacturers. It was important to welcome interested parties from not only the western North Carolina area and other parts of the state but also from neighboring states including Tennessee, South Carolina and Georgia. Membership of this consortium evolved during the intervening years to include the following participants and supporters: Progress Energy Carolinas; Duke Energy; Santee Cooper; Full Circle Solutions; Land-of-Sky Regional Council; NC Department of Pollution Prevention and Environmental Assistance; Ecusta Business Development Center; Blue Ridge Paper Products; Jackson Paper and Manufacturing Company; Miller Perlite; Appalachian Products; General Shale Brick; Metromont Materials; Small Business Technology Development Center of the University of North Carolina system and North Carolina State University The initial development program conducted at the Minerals Research Laboratory (MRL) was to formulate an acceptable LWA product, which fulfilled user specifications for light weight concrete block and structural concrete application. Support work and program coordination efforts were furnished by retired technical volunteers in WRP. The work advanced steadily, using proven technologies well established in the mineral industry, to generate a very satisfactory LWA. The consortium then concluded that a more comprehensive CCB conversion program would have more appeal for full scale manufacture and commercialization, if a variety of products from CCB separation were generated. This product assortment would include bottom ash, low carbon fly ash, recovered carbon of high purity, as well as the synthetic LWA. The bottom ash would serve the concrete block market, the fly ash was in demand for ready-mix concrete, and the high carbon product could be pelletized and used as a fuel for reburn or by the steel industry, and the LWA was a sought-after component for light weight concrete applications. After scouting all these potential markets and finding them to be viable, the consortium then inaugurated an integrated pilot plant program for the CCB separation and conversion. The plan was organized in three (3) parts: (1) Phase I ? bench scale evaluation studies (2) Phase II continuous pilot plant evaluation and (3) Phase III ? conceptual commercial plant design including marketing efforts and attraction of business entrepreneurs to build a full scale manufacturing plant. Phase II would serve to validate the process in a continuous mode and produce substantial quantities of products for preliminary marketing efforts and for demonstration-of-use purposes. The consortium agreed to the name, CAROLINA ASH PRODUCTS, (CAP), for the integrated pilot plant program. The products generated might be designated with the CAP label as: bottom ash would be named CAP Granules, low carbon fly ash would become CAP Ash, recovered high carbon product would be CAP Carbon, and LWA would have the name CAP Stone. Phase II of the program processed 20 tons (18 t) of ponded ash from Progress Energy storage at a rate of 600 lb (271 kg) of raw ash per hour with favorable results. PRELIMINARY STUDIES Prior to committing laboratory research and development effort as well as support and coordination activities to this program, it was necessary to determine (1) the level of need for a freshly launched CCB reutilization program in this state and (2) what degree of versatility was necessary for such a process. State agency records and a survey of recent boiler operations indicated that in the state of North Carolina at least 77 facilities manage CCBs from their boiler operations. Despite continuing development efforts in more eastern parts of the state, the use of CCBs for commercial applications has not increased to a level which alleviates the need to store vast quantities in private monofills on the generator?s property. More than 1.25 million tons (1.13 million t) of CCBs are landfilled in NC annually, with 300,000 tons (271,985 t) per year generated in western NC alone. Many different boiler types, which span both very old units and those that are modern and efficient, were to be found. These included stoker-fired units, pulverized coal boilers, slag-tap furnaces, and fluidized bed combustion boilers covering a range of sizes. Any systems designed to separate CCB components from all these sources and convert them to useful secondary products would need broad processing latitude and flexibility. Up to the present there has been a paucity of research done in the western part of the state to find productive alternatives to storage in landfills. With tipping fees in our largest landfill now approaching $40 per ton ($44 per t) and escalating transportation fees (about $200 per truckload up to 40 tons, traveling a distance of 25 miles), the problem has become urgent both economically and ecologically. A well-designed, integrated wet process for CCB separation into value-added products had much potential to be less expensive than landfilling as well as to provide saleable materials with acceptable profit margins. These preliminary investigations also revealed that other major waste streams, in particular paper mill sludge and municipal and animal waste biosolids were important candidates for priority attention. Since these biosolids could furnish the organic component of a synthetic LWA product, they could be consumed as part of the same program. This added interest value to a growing list of partners to support and participate in the program.

Jan 1, 2009

By R. D. Begley

This paper will present detailed design drawings of a flexible single floor residential superstructure proposed for both longwall and room and pillar mining conditions. All efforts were made to provide an immediately available economical alter- native for future home builders on subsidence prone land. Based on this fact, a basement was not included in the design because additional costs and measures would be required to minimize cracking and leakage. A cost comparison with a traditional superstructure demonstrated that this would be a cost effective alternative. The criteria used to determine the design of the residential structure was as follows: 1. The appearance should not be different then a typical three bedroom residence; 2. Only commercially available devices and present architectural and engineering technology should be used to achieve the required "flexibility" of the super- structure; 3. The structure as completed would be capable of resisting a predetermined amount of vertical and horizontal movement; and 4. If the structure was to experience stresses beyond its capabilities, it could be easily removed from the foundation and releveled.

Jan 1, 1986

Using mines in Canada, Boart Longyear, a leading provider of drilling services and products, has put its Stage 3 Coring Bit to the test and each time the bit has passed the test with great success. After more than a year in the field at a major mine operation in Sudbury, Canada, the Stage3 coring bit broke life records to become recognized as the most productive design in the industry. In addition to the proven advantage seen in regular bit life increases of as much as 300 percent in some cases, the design is quickly being recognized for its cost-saving operational impact. In Sudbury, the mine operation realized actual cash savings of more than C$45,000 within an eight-month period by making the switch to Stage3 bits. For years, the Sudbury Basin team has relied on the Alpha Extended Crown bit with the Express Waterway geometry option, ordering approximately 500 units per year. This 07 COM ECEX configuration performed well in medium-hard, non-abrasive to ultra-hard, non-abrasive formations with an average bit life of 150 m (490 ft). While satisfied with the performance of the Alpha Ex-tended Crown, the team agreed to put the new Alpha Stage3 to the test. Boart Longyear?s field engineers supplied five drill sites with Alpha Stage3 bits in a 07 COM configuration. After thoroughly testing the Stage3, the results were clear. Even with the well-known performance and versatility offered by the previously preferred configuration, the Stage3 set a new standard of bit performance. The new bit maintained its cutting edge for up to three times longer than the Alpha Extended Crown, a significant performance increase when compared to the 07 COM ECEX.

Jan 1, 2009

By Jonathan Taylor, Irwan Halim, Frederick (Rick) Vincent

The new underground facilities for the LINAC Coherent Light Source project at the Stanford Linear Accelerator Center in Menlo Park, CA, are constructed in very weak sedimentary rock interspersed with uncemented zones. In addition to several 21-footwide (excavated) tunnels, the NATM excavations include a large, 49-foot wide (excavated) cavern, an unprecedented size in this geology. The critical design issues include characterization of the weak rock, some shallow rock cover areas, and very stringent criteria for final invert slab movements within the tunnel. The design also incorporated severe seismic criteria, since the site is in close proximity to the San Andreas Fault.

Jan 1, 2007

By George P. Tateosian

Merchants perform a number of functions in the copper market. As a major distribution arm of the copper industry, they secure scrap and other copper bearing materials for processing into usable refined shapes. These are ultimately sold to fabricators. Merchants ' hedging and arbitrage activities help keep values in proper relationship from product to product or region to region. Through these switching and trading operations, they optimize the flow of copper from mine to consumer. And finally, merchants act as a repository for copper units during times of surplus and a stockpile from which to draw during tines of shortage.

Jan 1, 1979

By F. F. Roberto

Many techniques that are used to characterize and monitor microbial populations associated with sulfide mineral bioleaching require the cultivation of the organisms on solid or liquid media. Chemolithotrophic species, such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, or thermophilic chemolithotrophs, such as Acidianus brierleyi and Sulfolobus solfataricus can grow quite slowly, requiring weeks to complete efforts to identify and quantify these microbes associated with bioleach samples. Real-time PCR (polymerase chain reaction) assays in which DNA targets are amplified in the presence of fluorescent oligonucleotide primers, allowing the monitoring and quantification of the amplification reactions as they progress, provide a means of rapidly detecting the presence of microbial species of interest, and their relative abundance in a sample. This presentation will describe the design and use of such assays to monitor acidophilic microbes in the environment and in bioleaching operations. These assays provide results within 2-3 hours, and can detect less than 100 individual microbial cells.

Jan 1, 2009