Search Documents

By H Susanto, N Belluz, D Flint, A Edw

The Deep Ore Zone (DOZ) is a block cave mining operation exploiting a diluted reserve of 131 million tonnes grading 1.06 per cent copper and 0.81 g/t gold in the lower portion of the Ertsberg East Skarn System (EESS). The EESS is a calcium-magnesium silicate skarn containing in excess of 250 million tonnes of copper-gold ore, located in the Ertsberg Mining District on the crest of the Jawawijaya mountain range in the highlands of Irian Jaya, Indonesia. The EESS was discovered in 1968 where it cropped out at an elevation of 4050 metres above sea level. The Ertsberg Mining District is underlain by siliclastic carbonate and siltstone formations of Jurassic to Tertiary age. The sediments have been folded and are cut by major bedding subparallel and crosscutting structures. Intrusion of a series of igneous bodies post-dates folding and faulting. These I-type intrusions are the source for the copper-gold mineralisation found in the Ertsberg Mining District. The EESS is hosted by carbonates of the Tertiary Waripi and Faumai Formations that have been altered to calcium-magnesium silicate skarn and is situated on the southern limb of a northwest-trending syncline. The EESS is an essentially vertical tabular body with a vertical extent of at least 1200 metres and a lateral extent of up to 1000 metres. The width of the EESS averages 200 metres and locally is in excess of 300 metres. The northeast (hangingwall) contact of the EESS is a skarn reaction front in sudden contact with barren marbles. This contact coincides with a zone of localised faulting and brecciation. The EESS is bounded to the southwest (footwall) by the Ertsberg Diorite, a 3.25 Ma old intrusive. The DOZ block cave operation extends from 3040 metres above sea level to a maximum of 3388 metres above sea level, has a length of 860 metres and a maximum width of 350 metres. The DOZ is a high temperature skarn with a prograde forsterite/diopside mineralogy whose protolith is the dolomitic Tertiary Waripi Formation. The principal retrograde alteration minerals include tremolite, actinolite, serpentine, talc and chlorite. Grade is highest where bornite occurs in large dense complex intergrowths with magnetite and anhydrite. Grade has been locally enhanced in the DOZ by a late-stage pyrite-chalcopyrite hydrothermal alteration event with associated brecciation. Ertsberg Diorite along the footwall of the skarn is also included in the reserve where it is mineralised endoskarn or has been mineralised by porphyrytic or late stage hydrothermal alteration. Formation of the EESS was initiated by contact metamorphism during the intrusion of the Ertsberg Diorite with later metasomatic alteration during both prograde and retrograde phases. The bulk of sulphide mineralisation formed late in the retrograde phase. The EESS is open along strike to the northwest and down-dip with on-going exploration of these areas. Current exploration is targeting both endoskarn and porphyry style alteration and mineralisation of the Ertsberg Diorite.

Jan 1, 1999

By F. M. C. C. Vieira

Four mining alternatives for exploiting an ultra-deep orebody were assessed through a multidisciplinary evaluation process which involved: the generation of a 3D geological model; the design and scheduling of life-of-mine layouts; the analysis of anticipated ventilation and cooling conditions; the study of rock-related risks of mining in ultra-deep stress environments; the logistic implications of transporting men, rock and materials; and, lastly, the economic implications of each option. Once results from the integrated mine design assessment were available, mine planners were faced with an important problem to solve: how to identify the optimal mine design alternative when numerous assessment measures and multiple decision criteria needed to be considered simultaneously? To address this ‘multiple-attribute decision problem’ and arrive at the ‘optimal layout for ultra-depth’, a generic decision methodology that uses principles of ‘utility’ was applied. The methodology assumes that ‘single-value risk estimators’ do not account for the inherent variability of real conditions. Therefore, risk estimators were represented by statistical distributions of their incremental changes, where applicable. The stochastic variables, once defined, are used as inputs in the ‘utility’-based layout decision scheme. This ‘utility’-based decision methodology offers a framework for mine design decisions to be made objectively, when complex trade-offs between multiple risk domains need to be considered simultaneously. Upon applying it, one of the layouts emerged as the preferred alternative. Keywords: Utility; mine design; multiple-attribute decision; layout selection

Jan 1, 2003

By Reno H. Sales

Our colleagues cannot in the future earn reputations and medals for achievements in milling and smelting ore and for successful management of mining companies, if some one doesn't keep finding and mining the ore to mill and smelt and to provide the basis for the good management. Good ore seems sometimes to be quite helpful to good management, and good ore is not as easy to find as it used to be. And there are still more reasons, why—when this honor had been decided upon and named for Mr. Daniel C. Jackling—it should be initially conferred on Reno H. Sales. . The terms of reference of the award are that it should be conferred upon an individual working in the fields of mining, geology, geophysics, who has made an outstanding contribution to the progress of technology in one or more of those fields. And in this initial year (the earlier years are the easiest) just that was done. I think I could get away with it amongst the old-timers of my generation if I say that this time they made the award to the individual, who made the outstanding contribution. But, as Al Smith used to say, "Let's look at the record." Really, the record is mixed up a little with extra-lateral litigation—the old-time "apex cases" under Section 2322 of the Revised Statutes. Reno Sales doesn't like such litigation, but there is little question that the urgency, generated by conflicting claims of intra-limital and extra-lateral rights, and consequent necessity for committing to records and maps the complications of Butte structure, did advance—and by several years—the first continuous, accurate, systematic, and scientific portrayal of the geological and mineralogical details of what is, after all, the most important and the most complicated copper district—at least in North America. Prior to Sales' time, some of the most eminent of geologists often waived details. One geologist took the judge to the window to show him the Rarus fault going through a notch in the Continental Divide. The entertaining testimony in the Bluebird litigation was as perfect in literary style as it was innocent of the criteria by which faulting and lack of continuity of vein structure are now recognized. At any rate, this need for an accurate record of structure was in the background—to whatever extent it was, or was not, the etiological agent—for formation of the Geological Department of the Amalgamated Copper Co. in and about the year 1900. Charles W. Goodale was at that time the head of the Boston & Montana, and John D. Ryan succeeded William Scallon as the president of Anaconda Copper Mining Co. in 1905. Horace V. Winchell, for years a specialist in extra-lateral litigation, was perhaps the man who at that date had the vision, the persuasive weight with the management, and the willingness to defend the idea of large current expenditures (as then viewed) for a complete and sys-

Jan 1, 1955

By John G. Parker

Important quantities of gold, silver, platinum-group metals, selenium, tellurium, and arsenic are recovered in the processing of copper concentrates. The objective of this Bureau of Mines study was to determine the occurrence of these elements in copper ores and to trace their distribution during subsequent processing steps. The study describes the important areas supplying concentrates, precipitates, and unrefined copper to the copper smelting and refining industry in a composite of the years 1971-74. The relative importance of these areas as a source of the respective byproducts is assessed. The lack of certain quantitative and assay data, recycling of dusts and slags, and the addition of scrap to the feed often complicates calculations and estimations of the byproducts in the smelter-refinery throughputs. Such volatile or low-boiling point elements as arsenic, selenium, and tellurium may be lost in gaseous and other emissions in various processing stages, or they may be concentrated in slags and residues for which samples were not available. The effects of antipollution legislation to improve control of sulfurous and other emissions that may affect recovery of certain byproducts was noted. A section on newer technology illustrating hydro-metallurgical techniques that may affect the recovery of minor metals is included.

Jan 1, 1978

By Stone. Jon P.

INTRODUCTION Countries that are currently developing their mineral potential have unique information systems requirements to support these activities. The mining laws usually grant the State considerable authority over the process. In many instances, the mining laws give a government agency the responsibility for granting and controlling exploration permits and development concessions. This is the case in Costa Rica. The Direcion of Geologia, Minas, y Hidrocarburos (DGMH) of the Ministerio de Industria, Energia y Minas (MIEM) is responsible for the management and operation of the National Mining Register. This paper describes the results of two studies of the information system requirements to support the National Mining Registry as well as those supporting some of the other function of the DGMH. The first of the studies reviewed the situation before the installation of computer equipment. The second study evaluated the installed systems. BACKGROUND Historical Perspective Mining in Costa Rica is at present a relatively minor part of the economy. It consists primarily of industrial minerals and gold production. Gold production is largely by small-scale miners and may be more substantial than reported. There is considerable interest on the part of the Government in both having a better understanding of the existing mining industry and promoting future development. Mining law was first provided by the Ordinanza de Mineral (of 1830). This was replaced by the first Mining Code of 1953. Apparently, one of the first problems caused by the 1953 law was the granting of concessions which were not worked. A 1968 agreement with ALCOA also resulted in political conflict. The Government worked on a new Mining Code for many years and in 1982 the current Mining Code was enacted. Draft implementing regulations were prepared in April 1984. Mining Code of 1982 The Mining Code of 1982 addresses most aspects of mining in Costa Rica including the declaration that all mineral resources are to be the property of the State. The State may grant exploration permits and exploitation permits. The exploitation of hydrocarbons, radioactive minerals and certain water resources was reserved to the state. The DGMH was given authority to settle placer claim disputes, maintain a registry of exploration permits, and exploitation concessions. and generally supervise mining activity. Towards this, the Mining Code of 1982 includes rather detailed requirements for the processing of application for permits and concessions. Mining Code Application Requirements The following briefly describes the requirements to give the reader a feeling for the complexity of the process. Currently, over 1,000 active applications, exploration permits and exploitation concessions are being monitored under the process. The number remains relatively consistent in that the number of new applications is usually about the same as the applications that are put aside. The time and date of the filing must be certified by the DGMH. The application must include all the information specified in the Mining Code. If incomplete, DGMH must notify the applicant of the deficiencies or omissions and direct that the applicant correct the deficiencies or omissions within 8 business days (a single 30 business-day extension is allowable). If the applicant does not respond as directed, the application is deemed as not having been filed and the pertinent information is placed in the files. The DGMH must reject the application outright and direct it be placed in the files in the following cases: (a). If the new application covers the area of a previous permit or concession, either being processed or already granted.

Jan 1, 1987

By M. Radwan, S. Shimada, S. Z. El-Tawil, K. A. El-Barawy, Y. Miyamoto

This study presents the results of synthesizing monolithic siliconoxynitride, Si2N2O, ceramic from a mixture composed of reclaimed silicon and natural desert sand by using the nitriding combustion synthesis method. Single-phase Si2N2O powder was prepared by the combustion of a mixture composed of silicon and pulverized sand in 3 MPa nitrogen gas. The combustion reaction completed in 2 min and the combustion temperature reached 1577°C.The as-synthesized Si2N2O powder is agglomerate of fine particles with sizes < 5 µm and has various morphologies; rod-like and irregular crystals, irregular kinking, hollow crystals and grown pseudo-hexagonal prismatic crystals. Porous Si2N2O compacts (24.5–47.1% porosities) were fabricated from the synthesized Si2N2O powder at different calcia-alumina additives (5–20 wt%) by normal sintering at 1500°C for 1 hr in N2atmosphere.They showed superior oxidation-resistance at high temperatures up to 1500°C in an oxidizing atmosphere of Ar/O2/H2O(70/20/10 kPa).Near-full dense Si2N2O compacts were also successfully fabricated from the synthesized Si2N2O powder with 5 wt% oxide additives by using the spark plasma sintering at 1600°C.DenseSi2N2O had good mechanical properties (18.7 GPa Vickers hardness, 3.3 MPa.m1/2fracture toughness and 363 MPa strength) and excellent chemical and oxidation resistance.

Jan 1, 2004

By N. T. Lowe

The National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory (SRL), investigated a means to evaluate the potential impact of surface conditions above underground mines on emergency response activities. Recent events have highlighted the need to conduct critical emergency operations on the surface above underground work areas. Accessibility and usability of the surface, such as the ability to drill holes or deploy seismic monitoring or through the earth communications systems, are an important consideration for emergency response planning. This paper identifies critical surface conditions such as: surface waters, valley fill, highways, railroads and significant structures that must be considered in emergency response planning and in the conduct of emergency operations as they relate specifically to the seismic detection of trapped underground miners. Results of case studies indicate a need to consider the impact surface conditions may have on emergency response capabilities.

Jan 1, 2009

By S. Y. Chen

A new process comprising metallizing reduction, magnetic separation, and electroheat melting separation is proposed with the aim of achieving high recoveries of iron, vanadium, and titanium from vanadium titanomagnetite. The effects of magnetic intensity, reduction temperature, reduction time, carbon ratio, and coal particle size on the efficiency of reductionmagnetic separation were investigated, the reaction mechanisms elucidated by SEM and EDS analysis, and the optimal process parameters established. Recoveries of up to 80.08% for titanium, 95.07% for iron, and 71.60% for vanadium were achieved. The reduction sequence is shown to be: Fe2O3 ? Fe3O4 ? FeO ? Fe; Fe2TiO5 ? Fe2TiO4 + TiO2 ? Fe + FeTiO3 ? Fe + FeTi2O5 ? Fe + TiO2.

Jan 1, 2014

By William R. Barton

Sampling to determine development potential of beryllium deposits was conducted at 31 New England localities. A total of 54 additional areas where the geochemical environment appeared favorable were sampled to determine if economically interesting percentages of beryllia (BeO) might occur. Newry Hill-Plumbago Mountain, Maine, Iron Mountain, N.H., and Long Island, Maine, were investigated in some detail to determine the size and grade of deposits. The mineralized pegmatites at Newry Hill-Phunbago Mountain are extensive but very low grade; at Iron Mountain the ore bodies are very rich but of small volume; at Long Island beryl occurs with molybdenite, wolframite, and scheelite, but the tonnage of ore was not determined.

Jan 1, 1968

By R. Zunich, E. Rybinski, M. Grondin, B. Flintoff

It is uncommon these days to read a business magazine or newspaper without finding a reference to Knowledge Management (KM), and its critical importance to corporate success. One definition of KM is: “getting the right knowledge to the right people at the right time and helping them to put information into action in such ways that strive to improve organizational performance.” In the minerals processing industry we could assert that we have been practicing this for years through effective operator training. In most cases we would probably be wrong. Training has certainly filled the need of addressing safety and basic operational issues, but we must collectively focus on education (learning), and the difference, as measured in outcomes, is not at all subtle. This paper briefly examines the history of training and education in the mining industry, and looks in more detail at the impact of one company’s approach to empower its workforce, while keeping the ultimate goal clearly in mind: “The great end of knowledge is not knowledge, but action.” (T.H. Huxley)

Jan 1, 2001

By B Moynihan

The Roa Opencast Coal Mine is situated at the north-eastern end of the Greymouth Coalfield. It lies on an eastern flank of the Paparoa Range, 16 km north-east of the town of Greymouth on the West Coast of the South Island. Road access is via a sealed road from Blackball to Roa, then by a 5.3 km all weather, gravel road, which gains 340 m in elevation from 190 m RL at Roa to a maximum height of 530 m near the opencast.

Jan 1, 1993

Mining is a fundamental activity on which modern society and the world&apos;s economy are entirely dependent. Mining investors, large and small, invest on an international scale, frequently being active in several countries. &nbsp; Prior to committing investment to new countries, the prudent investor will consider the risk involved by analysing a number of physical, financial, administrative and political parameters that impact on the potential financial returns it is seeking. This paper considers these risk factors in relationship to New Zealand and six competitor countries. The conclusion is that for reasons largely within the control of our politicians, New Zealand is a high risk country for mining investors.

Jan 1, 1993

General recognition of the potential benefits of utilizing advanced technology has focussed public attention on the organisation of tertiary education. This has produced a situation where opportunities exist for significant changes to be implemented. The challenges to Mining education in this environment of change are analysed with respect to the setting of education objectives, the role of centres of education, course structures and student access to courses. The scope of the analysis includes formal courses for professional education and technical training, and programmes for continuing education and postgraduate research. Previous significant advances in mining technology illustrate the importance of encouraging the establishment of an extensive involvement with mining education. Education cannot be the sole responsibility of professional academic organizations; significant industry participation is essential. Methods of achieving this interaction are discussed. Major changes in techniques available for disseminating information provide a significant incentive to assess the relevance of existing course structures and restrictions on student access to courses. Establishment of a less rigidly progressive system of education is discussed with respect to the development of the full potential of computer based learning. This will expand the availability of mining education to include remote locations. The practical feasibility of such changes and recognition of the value of education as a commercial resource could also increase overseas involvement in Australian mining education. Benefits of such changes and problems that may develop if accreditation systems are not also changed to take account of new technology are outlined.

Jan 1, 1989

By S. Ngidi

Palabora Mining Company operates a low grade underground copper mine situated in the Limpopo Province, South Africa. Full production was first reached in May 2005 after a successful transition from an open pit operation to an underground block cave operation. The operation faces a number of technical and operational challenges, not the least being fragmentation of a competent rock mass and external dilution. The cave is subdivided into three main sectors being the east, the west and the central sectors. Caving was initiated from the weaker central sector, which has the majority of its drawpoints located directly under the open pit bottom currently filled with about 130 million tons of waste material from the pit wall failure incurred in 2004. About 48% of the ore reserve has to be extracted from the western sector, which has a much courser fragmentation compared to the other two sectors and only 25% from the central sector with the finest fragmentation. The main constraint during the ramp-up stage has been secondary breaking of drawpoint blockages. Ground-breaking secondary breaking and cave management initiatives and practices have made it possible for Palabora to realize and sustain high production rates.

Jan 1, 2007

By H. E. Bartlett

In the operation of some flotation plants treating platinum ores it was found that there were imbalances between the inputs and outputs. The inputs and outputs were sampled as slurries and it was determined that the imbalances arose from biases in the sampling, despite the samplers having been designed according to well-established rules. The launders feeding the sample cutters, and the sample cutters themselves were redesigned using finite element analysis to model the flows. A new set of design rules were formulated. The application of a Components of Variance Analysis, to determine the variance of primary and secondary sampling and of analysis in the lab for a concentrate is presented to illustrate the need for frequent sampling of process streams.

Jan 1, 2002

By Van Dusen M

The involvement of concerned parties in all aspects of the Lihir Project from an early stage has promoted good relations between all groups. Activities involving landowners, the Lihir community, the New Ireland Provincial Government (NIPG) and the prospective developer include the Lihir Liaison Committee, Lihir Working Group, Environmental Planning Committee, Provincial Mining Task Force and the Lihir Mining Area Landowners Association (LMALA). With modifications, the Lihir Liaison model may be of use in promoting good relationships among parties in other mineral developments.

Jan 1, 1991

By C J. Adams, H J. Campbell, A J. Tulloch, I J. Graham

New Zealand can be regarded as a rifted part of mineral-prospective eastern Australia. Geologically credible comparisons between selected trans-Tasman and SW Pacific geological provinces and units, especially those that contain significant mineralisation in Australia, can help provide a useful exploration framework for New Zealand. As part of a six-year Mineral Wealth of NZ and its EEZ (MWE) research programme, we have targeted selected geological units in eastern Australia for comparison and contrast with their potential New Zealand counterparts. In future years, the programme will focus on geological units in New Caledonia.

Jan 1, 2005

By A. D. Mukherjee, H. N. Bhattacharya

Middle Proterozoic sulphide ore mineralisation occurs in isolated blocks of the NE-SW trending Delhi fold belt composed of Delhi Supergroup rocks. The Ajari-Basantgarh-Pipela belt forms part of the longest, widest and westernmost tectonic unit of the Delhi fold belt and consists of amphibolites, metapelites, quartzites and carbonates. The metapelite lenses and associated amphibolites host pyritic copper mineralisation. Mineralisation takes the form of sheet-like bodies consisting of ore lenses of various sizes interlayered with host or associated rocks. Massive, banded and disseminated varieties of ore are found. Pyrite is dominant with subordinate chalcopyrite and sphalerite. Pyrrhotite, galena, cubanite, mackinawite, marcasite and freibergite constitute the minor minerals. The characteristic features of the ores suggest a possible correlation with Besshi-type deposits, and the closely associated amphibolites are interpreted as low-K tholeiites of a fore-arc setting

Jun 19, 1905

Mount Read is &apos;situated in the county of Montagu, on &apos;the west coast of Tasmania, about 20 miles inland from. Remine in an easterly direction, 15 miles northerly from Mount. Lyell, and 30 miles south-east from Mount Bischoff, and is one of the mountains forming the west coast range; it rises to a height of 3890 ft. above sea level.About eleven years ago the first mineral section was taken up on Mount Read by a Hobart company, known as the Mount Reid Silver Mining Company, consisting of 25,000 shares its holding consisted of one section of 80 acres, held under mineral lease. Prospecting was carried on for some months under great disadvantages, as all supplies had to be carried up the mount from Dundas, a distance of nine miles, on men&apos;s backs, until a pack track for horses was made.The track rises 2500 ft. in the first five miles, and then falls 200 ft. from that point to the mines, which are at an altitude of 3000 ft. above sea level, and at a point about two miles westward from the summit of the mountain, approximately midway between Mounts Read and Dundas.

Jan 1, 1901

By A. Sadik

The proliferations of media sources and non-profits organizations in Ghana have put the negative impacts of mining on the ?spot?; this has resulted in public outcry about mining. Although, the gold mining industry has responded by implementing several voluntary measures to ensure sustainable mineral development, these critics label such measures as ?green wash?. In this study, a content analysis of newspaper articles of the Ghana Web Database was carried out after the collection of a total of approximately 900 newspaper articles from it. The data were statistically analyzed to chronologically examine the main media view points and the changing perception of mining issues as reported by private and public media. The results showed government, mining industry (Gold), illegal miners and non-profit & community groups as the main media view points and total of twenty-eight related gold mining sustainability issues. The findings of this study could be used by the gold mining companies to improve upon the communications of their unknown sustainable mineral development measures and to design effective communications and education programs for the public.

Jan 1, 2009