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By R. J. Hundermark, L. R. Nelson

"The critical importance of tap-hole design and management for furnace performance and longevity is explored through examining some of the specific matte, metal, and slag tapping requirements of non-ferrous copper blister and matte converting and smelting, ferroalloy smelting, and ironmaking systems. Process conditions and productivity requirements and their influence on tapping are reviewed for these different pyrometallurgical systems. Some critical aspects of the evolution of tap-hole design to meet the diverging process and tapping duties are examined. Differences and similarities in tapping practices and tap-hole management are reviewed. Finally, core aspects of tap-hole equipment and maintenance are identified – aspects that are considered important for securing improved tap-hole performance and life, so pivotal to superior furnace smelting performance. IntroductionThe sheer diversity of tapping configurations used on industrial pyrometallurgical operations is at first bewildering. They range from historical tilting furnaces without tapholes to modern eccentric bottom tapping (EBT) tilting and/or bottom slide-gate electric arc furnaces; to classical single tap-hole multiphase tapping (e.g. metal/matte and slag); to dedicated phase tap-holes (e.g. dedicated metal/matte-only and slag-only); to dedicated phase multiple tap-hole configurations (up to eight metal/matte-only tap-holes and six slag-only tap-holes); to more esoteric metal/matte-only siphons and slag overflow skimming, e.g. Mitsubishi Continuous Process (Matsutani, n.d.). This can be further complicated by periodic batch tapping; consecutive tapping on a given taphole; alternating tap-hole tapping practice; near-continuous slag-only tapping, with discrete batch matte/metal tapping on higher productivity, but low metal/matte fall (<20% by mass feed) Co and Ni ferroalloy and platinum group metal (PGM) matte furnaces; near-continuous tapping through batch tapping of individual tap-holes that are opened consecutively (Tanzil et al., 2001; Post et al., 2003); to fully continuous tapping on coupled multi-furnace cascades (Matsutani, n.d.)."

Jan 1, 2016

This article focuses on TurkeyÆs gold potential with respect to exploration, development and operation after 1985. Apart from TurkeyÆs geology, which offers a substantial number of volcanic-associated gold (Ag) and gold-copper (Au-Cu) projects, there are numerous other factors which make the country a favourable place for mining. Turkey has a mining history which goes back to pre-Roman times and an excellent mining code which ensures security for long-term production. In the country, the Government and local villagers are very positive and the country works extremely well logistically with excellent road and telecommunication links. The opportunities for new discoveries in Turkey are very high. Moreover, Turkey has its eyes turned west as it moves towards joining the European Community and it is no surprise that international companies believe it has got its timing as well as its partner relationship right. Newmont, Teck Cominco, BHP Billiton, Rio Tinto, Eldorado Gold, etc all have direct or indirect interests in Turkey, as do an increasing number of midtier and junior exploration companies. Turkish Koza Gold Mining is the first Au producing company of Turkey. The Eldorado Gold owned 245 t Kisladag Au deposit in Western Turkey is currently also producing Au. In the meantime Anatolia Minerals Development is advancing the 131 t resource at the C÷pler Au deposit in North Eastern Turkey. These are significant world-class deposits. Further encouragement for investment in the Au mining sector has been provided by the introduction of a new mining law in 1985. Foreign investments in the country were encouraged and have seen a rapid increase in the last two decades. Gross domestic product (GDP) growth is in excess of five per cent per annum, inflation is down from 70 per cent to single figures, the budget deficit has been cut by 40 per cent to 11 per cent and industrial output and productivity are increasing rapidly. Turkey is politically and economically stable, is a member of the European Customs Union, has a supportive mining legislation, is highly prospective and under-explored and hosts significant recent gold discoveries.

Jan 1, 2007

By H. W. Earnest

This report covers the results of a two-phase study to determine the feasibility of underground disposal of retorted oil shale. Two mining methods, chamber and pillar mining and sublevel stoping, were specified for backfilling. Phase I of the study covered the evaluation of hydraulic, mechanical, and pneumatic transport and stowing systems, individually and in various combinations, and the selection of the most feasible methods. Conveyor transport and stowing and a combination conveyor transport and stowing with pneumatic topfilling were selected for detailed study of phase II. Phase II activities included detailed engineering analysis and design of the selected systems, an engineering economic analysis, and a cost comparison with total surface disposal of retorted oil shale. An extensive literature search was conducted and the bibliography is included in the report. Research done under Contract No. J0265052 by the Cleveland-Cliffs Iron Co. Available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., Bruceton and Pittsburgh, Pa., and Spokane, Wash.; U.S. Department of Energy facilities in Carbondale, Ill., and Morgantown, W. Va.; National Mine Health and Safety Academy, Beckley, W. Va.; and National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C. Order ONLY from NTIS:

Jan 1, 1978

By T. Gupta, T. Ghosh

"Rare Earth Elements (REEs) and their compounds are essential for numerous modern high tech applications such as renewable energy technologies, catalysts and defense applications. The destabilization of REE pricing owing to the global demand and supply deficit has forced many countries to re-evaluate the possibility of indigenous production of REEs. Cost effective and eco-friendly opportunities are being widely explored for extraction of REEs from non-conventional mineral sources such as coal and coal byproducts to stabilize the supply chain. Coal from Central Alaska (Healy Coal Mine) and Southern Alaska-Cook Inlet (Wishbone Hill) province have been found to possess elevated REE concentrations as compared to average world coal estimates. The objective of the study is to enrich the REEs in the fine size fraction (-75 Microns) from Healy and Wishbone Hill by froth flotation technique. A Box-Behnken design was applied for modeling and optimization of some operating variables on the flotation to maximize REE enrichment. The variables studies were frother dosage, pulp density (% Solids) and collector dosage. Experiments were carried out using a statistical design and the main and interaction effects on response variable was evaluated by analyzing 3D response surfaces. Based on the experimental results the optimum flotation conditions for maximum REE enrichment in the froth fraction was obtained at 4.2% Solids and 32.7 ppm of frother dosage for Healy coal sample and 10% Solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic equation for modelling and optimizing the response variable is found to be independent of collector dosage for both the coal samples. INTRODUCTION Alaskan coal deposits are distributed in three major coal provinces and are in Cretaceous and Tertiary rocks. The climate, vegetation type and sedimentation process has attributed to low sulfur content (averaging 0.3 percent) in Alaskan coals compared to other coal deposits found across the globe. In Central Alaska-Nenana and Southern Alaska-Cook Inlet coal province coal resources are contained in Tertiary rocks while bulk of the Coal resource in North Slope coal province is contained in Cretaceous and Tertiary coal bearing rocks [1]. Coals from Central Alaska- Nenana (Healy) and Southern Alaska-Cook Inlet province (Wishbone Hill) have been found to possess elevated concentrations of critical REEs as compared to the amounts present in world coals (Figure 1). The Wishbone Hill deposit is considered a relatively small deposit, with about 14 million tons of identified reserves, compared to Healy which has over 500 million tons identified [2]. The REE concentrations up to 286 ppm and 524 ppm on ash basis have been reported by Gupta et al. in 2016 with elevated concentrations Ce, La, Y and Nd which are expressed to be of critical importance by US Department of Energy. Accordingly, the two coal samples possess the potential to be used as a REE resource in the near future under favorable socio-economic and geo-political scenarios. [3, 4]"

Jan 1, 2017

By Compiled by Staff

"INTRODUCTIONThe U.S. Bureau of Mines (USBM) was established in the public interest to conclude inquiries and scientific and technologic investigations on mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increaseee efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the U.S. Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, USBM reports the findings of its research and investigations in its own series of publications and also in articles that: appear in scientific, technical, and trade journals; in "" proceedings of conventions and seminars; in' reference books; and in other non-USBM publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make this kind of list both necessary and valuable.This edition describes reports and articles published during calendar years 1992 and 1993. It supplements the 50-year list of Bureau publications from July 1, 1910, to January 1, 196O 2; and these 5- year lists of publications and articles: from January 1, 1965, to December 31, 1969 4, from January 1, 1970,to December 31, 19745 , from January 1, 1975, to December 31, 1979 6 , from January 1, 1980, to December 31, 1984 7 , and from January 1, 1985, to December 31, 1989 8."

Jan 1, 1994

By John Freer

On 25th November, 1983, nearly forty members of The South African Institute of Mining and Metallurgy, together with Doris Gardner and Judith Money from Kelvin House, travelled by luxury motor coach to Secunda, there to visit the coal-mining and conversion operations of Sasol Limited.

Jan 1, 1984

On Dec. 20, 2013, an 8-m (26.2-ft) diameter Robbins hybrid single shield/earth pressure balance tunnel boring machine (EPB TBM) was launched to bore the Grosvenor decline tunnel for Australia?s Anglo American coal mine. The machine was built using onsite first time assembly (OFTA) in order to fit within a tight project schedule. Assembly at the remote jobsite near Moranbah, Australia took about four-and-a-half months, and then the machine was walked down into a launch tunnel. Two decline tunnels, at grades of 1:6 and 1:8, will be used for mine access to new coal seams. The hybrid machine is tackling mixed ground conditions ranging from sand and clay to varying types of sedimentary hard rock up to 120 MPa UCS, as well as coal seams. Methane gas is expected to be present throughout the tunnel, so the machine has been designed as explosion-proof-compliant to ERZ-1. ?Grosvenor is the first underground coal mine in Queensland to use a TBM for drift construction,? said Glenn Tonkin, Grosvenor project director. ?We are proud to be pioneering this technology.? Only about 300 m (984 ft) of ground in each decline tunnel is expected to require EPB mode, while the rest of the tunnel will be bored in hard rock mode. Thus, the design was optimized toward hard rock excavation.

By David C. Jonson, W. Bruce MacKenzie, Arthur A. Bookstrom, Vaughn E. Surface, Neil K. Muncaster, Stewart R. Wallace

In mid-Tertiary time a wet silici-alkalic magma penetrated the Precambrian rocks of what is now the Tenmile Range of Central Colorado and formed the Climax Stock. The stock is a composite one and was intruded in four separate irruptions, each giving rise to a major hydrothermal event. The first three of these produced large stockwork ore bodies that cap and flank the tops of their respective source intrusives; the fourth, and last, yielded almost no commercial mineralization. The ore bodies and their related zones of alteration are circular to ring-shaped in plan and arcuate in section. The different phases of the stock are so positioned with respect to each other that many of the circular and arcuate zones of mineralization and alteration overlap or are juxtaposed. Evidence of a time separation between the different ore bodies is found in certain dikes that were intruded between periods of mineralization and are well mineralized in one ore body but are barren in another. If it is assumed that the parent magma at Climax contained 10 per cent "water," that the "water" contained 0.1 grams per liter of molybdenum, and that the processes of extraction were 100 per cent efficient, then approximately 10 cubic miles of magma would be required for the formation of each ore body. The volume requirements, taken in conjunction with the cross-sectional areas of the different phases of the stock to explored depths, suggest to the authors that each magma chamber was columnar, extended to a depth of thousands of feet, and was connected with a much larger master reservoir. The repetition of similar intrusive, structural, and hydrothermal events, indicates periodic tapping of this reservoir. A regular chemical evolution of the parent magma is suggested by the systematic change in metal ratios and differences in the sites of deposition, relative to the source intrusive, in each of the four separate igneous hydrothermal stages. The preparation of ground was due to changes in magmatic and/ or hydrothermal pressures within the igneous-hydrothermal columns; small, repeated, up and down movements of the rock enclosing the tops of the columns formed the stockwork fractures into which the mineralizers penetrated. The forceful emplacement of each successive phase of the Climax Stock resulted in a slight doming and rotation to the westward of the earlier-formed geologic features. Postore normal displacement along the Mosquito fault is estimated at about 9000 feet. Part of one ore body was cut by the fault and lies at depth below the Paleozoic sedimentary strata on the hanging wall. On the footwall side of the fault, subaerial erosion and glaciation removed a large part of one ore body and uncovered the top of a second.

Jan 1, 1968

By B. Genc

Safety in South African mines is a subject of significant interest, since many mining companies are experiencing production deficits due to safety-related stoppages. In this paper, safety data from the South African platinum mining sector is analysed for the period 2006 to 2010. The data was obtained from company annual reports as well as the Department of Mineral Resources, and analysis in the study is limited to injury and fatality data only. The overall safety performances of companies in the sector are compared, and opportunities for benchmarking and recognising potential sources of best practice amongst platinum miners are identified. Improving safety usually incurs a cost, and mining companies are particularly conscious of the importance of controlling costs. However, cost considerations often deal only with direct costs, and it has been shown that indirect costs are usually far more significant. Therefore, a greater safety spend will usually result in the creation of value for the mine since it will reduce the indirect costs associated with accidents. The results of some recent research in this area are presented. In this light, where available, the financial performances of mining companies in the sector, obtained from published annual results, are included in the benchmarking exercise to determine whether there is any correlation with safety performance.

Jan 1, 2012

By Alice M. Chieruzzi

This Country Documentation Report presents the development of economic indices for the Philippines for the period from 1970 through 1981. The work was done through the Bureau of Mines, Minerals Availability Program, under Contract number J01225001. This contract calls for the development of twelve index time series describing factor input costs in the mining sector of 95 countries. The twelve index time series describe the costs of: 1) mining wages, 2) construction wages, 3) equipment and repair parts, 4) bits and related steel, 5) eimber and lumber, 6) fuel, 7) powder and balsting agents, 8) tires, 9) construction materials, 10) industrial materials, 11) transportation, and 12) electrical power. These indices combined with weight factors being developed by the personnel of the Minerals Availability Field Office (MAFO) of the Bureau of Mines in Denver, Colorado, will be used to perform instantaneous updates of all costs relating to the mining industry. The indices were developed primarily for use in the Bureau&apos;s Minerals Availability Program in assessing the worldwide availability of nonfuel minerals.

Jan 1, 1983

By Laura A. Sanders

Mineral scale formation is prevalent in numerous mining operations. Such scale formation can occur in the direct-contact heat exchangers ahead of an autoclave. In these heat exchangers, the incoming slurry comes into contact with steam in a stage-wise fashion, which is re-circulated from the downstream flash vessels to heat the slurry in stages ahead of the autoclave. Calcium sulfate scaling causes severe problems in mining operations where increased temperatures are involved due to rising temperatures promoting calcium sulfate scaling through a decreasing solubility. In a number of these operations, the scale formation can occur in the presence of mineral solids, where fine-grained charged particles are at concentrations in excess of 35%. Scale prevention is not difficult in standard aqueous systems; however, the presence of solids leads to significant deficiencies in the prevention of scale due to the adsorption of the polymer onto the charge solids instead of the polymer interaction with the scale. Therefore, a technical solution to prevent mineral scale build up occurring in presence of pulp slurry in mining operations is needed. Several novel antiscalant technologies were developed and evaluated which provided a substantial improvement in the scale prevention in such systems.

May 1, 2013

By M. De Ladurantaye-Noël, M. Laliberte

Selenium is widely present in the environment at usually low concentration. It is mostly present in the environment at higher oxidation states, i.e., as selenites and selenates (+4 and +6 oxidation states respectively). It is rarely present as selenides (-2 oxidation state) and almost never found as the element (0 oxidation state). Selenites and selenates are generally soluble in water, as such they cannot easily be removed from water by precipitation. Selenites can form insoluble surface complexes with metal oxides such as ferric hydrous oxide and manganese hydroxide, and can therefore be removed that way. However, it is not so common to find selenites in natural environments as it will quickly oxidize to selenate in aerobic conditions. Elemental selenium can also be produced from selenites or selenates by using a reduction process; the end product is a colloid that can be destabilized to be removed from water using the right chemistry. Because of their toxicity, selenides need to be handled with care, and if present, it can form insoluble metal salts or, at low pH, be emitted as H2Se, a noxious and highly toxic gas. The most favorable selenium forms for its removal are therefore selenite and elemental selenium. Organo-selenium species play a crucial part in understanding selenium toxicity. There are a great number of these species. Basically, any organic species that contains sulfur has an equivalent that contains selenium. Of particular interest is the substitution of sulfur by selenium in the two sulfur-bearing amino acids, cysteine and methionine, resulting in selenocysteine and selenomethionine. Methylseleninic acid (CH3SeO2H) is another organo-selenium specie which has been detected in water treated by biological processes and which is biologically active.

Feb 1, 2023

By Lindsay D. Norman

Computer models for simulating the construction and for calculating the properties of particulate solids in two- and three-dimensional systems (coverings of circles and packings of spheres, respectively) were developed. By simulating the physical process of constructing circle coverings and sphere packings, in which the circles or spheres were randomly selected from many different distributions of sizes, physically realizable loose random assemblies were simulated whose physical and geometrical properties were predictable with the computer. Many of these properties, such as the number of contacts, are extremely-difficult to measure accurately, or considerable ingenuity is required in their determination. All of these properties were easily and accurately calculated by the computer models for many different coverings and packings constructed from equal, discrete, uniform, and log-normal distributions of particles. In addition to the loose random assemblies, dense random covering and packing constructions were simulated whose properties are ideal upper limits for those of the loose random coverings and packings. The properties of the dense random coverings and packings, heretofore only obtainable by theoretical analysis, were also simply obtained. The statistical geometry of loose random coverings and packings was studied, and several new interpretations of the area-covering or space-filling requirements in these systems were made. In two dimensions, it was found that the properties of all loose random coverings are predictable by taking suitably weighted averages of the corresponding properties of just four kinds of polygons whose edges are defined by connecting the centers of mutually tangent circles in the covering. The distributions of these polygons that permit area-covering were determined, and empirical equations for predicting the density, average coordination number, and average pore area in loose and dense random coverings were formulated. The properties of loose packings were determined by performing a simplicial division of the computer-simulated assemblies to produce a unique set of minimum volume, space-filling tetrahedra whose edges connected the sphere centers in each packing. A simple empirical equation was formulated that permits the calculation of the average number of contacts in any sphere packing, random or regular. Some of the statistical geometrical properties of the simplicial tetrahedra in the computer-simulated packings were analyzed. The tetrahedron edge length distributions in all the loose random packings were nearly identical when the edges were presented in terms of sphere diameters, regardless of the sphere population in the packing. Moreover, the gap lengths in the loose packings were to an excellent approximation representable by a uniform distribution of sizes. The distributions of spheres in tetrahedra resulting from the simplicial division of the loose random packings also existed in the tetrahedra in dense random packings. These observations were employed in developing a unique method for predicting the geometrical properties of loose random packings without simulating the assembled packing. Instead, the space-filling simplicial graph could be predicted for any given density of packing of any sphere population. The cumulative packing properties of these tetrahedra were shown to be nearly identical to those calculated by all loose random packing simulations attempted in this investigation. The simplicial tetrahedra completely describe a packing and can therefore be used to predict all properties of interest.

Jan 1, 1971

By C. George Miller

"As the influence of governments has become more widely felt, the use of research techniques to analyze policy has increased. Mineral economics, as one of the foundations of mineral policy research, has grown accordingly. Policy research and analysis has been carried out within governments, university departments and the private sector. Each of these institutional environments has characteristics which influence the topics of study, the approach, the methodology and the output of the research. A brief survey of recent research activities provides illustrations of trends and developments occurring within this organizational framework.A radically different organization, the independent research institute, has begun to make an impact on policy research in recent years, and will have an increasing importance in the future. Combining certain features of the traditional research organizations, it nevertheless has important differences which are essential to its effective functioning. An overview of the formation, goals, organization and operation of one such institute is presented."

Jan 1, 1976

By M. K. Larson

The U.S. Bureau of Mines and Cyprus Shoshone Coal Corp. conducted a study of deformation mechanisms in strata around a longwall gate road system at two sites in an underground coal mine near Ham, WY. Of particular interest was timedependent (on the order of several months) roof deformation. Strata above and below the coal seam are very weak, carbonaceous mudstones that have cohesionless planes of weakness oriented along bedding, which dips approximately 8° to 16° at N 49° E. An extensive array of instrumented roof bolts, roof extensometers, and biaxial stressmeters were installed during development mining at these two sites under variable depth of cover [I83 to 335 m (600 to 1,100 ft)], seam dip (10° to 16°), and top coal thickness [estimated to be 0.30 to 0.61 m (1 to 2 ft) on the downdip side of the entry]. Bolt load and roof deformation histories during the entry development periods were compared. Bolt loads at site 2 were less than those at site 1, which is consistent with the amount of overburden. Deformation magnitudes at site 2 were similar to those at site 1, but deformation rates were approximately 44% greater and nearly constant over time, whereas the deformation rates at site 1 decreased exponentially over time. Also, most deformation occurred above the bolt horizon at site two, but extensometer measurements at site 1 showed that a significant amount of deformation occurred within the bolt horizon. The most significant factor that influenced bolt tension and timedependent strata deformation was strength and Young&apos;s modulus of the strata. Finite-difference models support this conclusion.

Jan 1, 1996

By Melitza Cornejo

La lixiviación con cianuro es el proceso utilizado por la industria minera para extraer oro y plata. El cianuro es un compuesto tóxico para la mayoría de los organismos vivos. Sin embargo, muchos microorganismos son capaces de tolerarlo e incluso degradarlo. En ese sentido, el texto caracteriza y analiza la composición de las comunidades microbianas de suelos y aguas contaminadas por residuos de cianuro, producto de la actividad minera en la región La Libertad a través de la metagenómica dirigida al ADNr. De forma que se logró aislar e identificar molecularmente 89 cepas microbianas, como los géneros Pseudomonas, Bacillus y Alcaligenes. Asimismo, la capacidad de degradación del cianuro ha sido establecida en base a pruebas in vitro considerando estas cepas, ya sea individualmente o en consorcios.

Jan 1, 2017

By P Guj, J A. Bell

The valuation of early-stage exploration projects requires a valuer to take into account a large number of uncertain value drivers, the interplay among which may be non-linear. This paper examines some of the key value drivers including geology, target metrics, project area and maturity, the market and the psychology behind the decision-making process. The commonly accepted valuation methods and their underlying logic are outlined, including a view on why they evolved, what value drivers they attempt to address and their potential shortcomings. These methods include the multiple of exploration expenditure, geoscience rating, expected values and market based methods. The potential future valuation methods of replacement values and neural networks are also introduced along with how to minimise heuristic bias and error within the market-based approach.CITATION:Bell, J A and Guj, P, 2012. Exploration value drivers and methodologies, in Proceedings Project Evaluation 2012 , pp 17-28 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By M. N. Rubin

This report summarizes the work performed under USBM contract J0100018. The purpose of this work was to document the currently available noise control techniques that can be incorporated into new coal preparation plants during the design stage. This was accomplished by reviewing the related experience of the contractor and subcontractor (Bolt Beranek and Newman Inc.), conducting an extensive literature search, visiting operating coal preparation plants, and contacting various equipment manufacturers. The treatments addressed include equipment substitution, changes in plant layout, and retrofit treatments for existing equipment.

Jan 1, 1982

By Adam Levy, Thomas Novak, Sampurna Arya, Joseph Sottile, Kozo Saito

The use of a woven wire-mesh screen as part of a flooded-bed dust-scrubbing system is popular in the underground coal mining industry. It is used in combination with a demister (mist eliminator) to remove dust from the dust-laden air. A study was conducted to measure the pressure drop across a flooded-bed, wire-mesh screen at different airflow rates in one-phase (dry) and two-phase (wet) conditions. Two empirical relationships between pressure drop and air velocity were developed for dry and wet conditions, respectively. In both cases, the form of the empirical relationships was found to be similar to relationships given by Sabri Ergun for high velocity, non-Darcy, single- and multi-phase flow through porous media. The experiments were repeated on a reduced-scale model of the wire-mesh screen, and the pressure-velocity relationships obtained from the full-scale prototype experiments were tested. The test results show validation of the full-scale empirical formulae on the small-scale model with an insignificant variation. This paper presents the empirical equations for pressure drop across the wire-mesh screen in dry and wet conditions. Researchers can use these equations as a tool to predict total pressure drops for wire-mesh screens of different scale sizes.

By H Hoogvliet

The Goondicum Crater industrial minerals deposit is located about 30 km east of Monto, Central Queensland, Australia. Early exploration programs in the 1990s found alluvial ilmenite along the banks of the Burnett River. This mineralisation was traced upstream to the Goondicum Crater. The Goondicum Crater is a topographic feature centred on a roughly circular 6 km diameter layered gabbro complex. Significant ilmenite, apatite, titano-magnetite and feldspar mineralisation are present in a weathered horizon up to 25 m thick. After several drilling campaigns in the Crater and subsequent feasibility studies, the project was developed by Monto Minerals Ltd, an ASX listed company, in 2007. However, the project never achieved production performance expectations and ran out of commissioning funds. The company subsequently went into voluntary administration in August 2008.In 2009, the RMM Capital group, of Brisbane, took control of Monto Resources Pty Ltd, and renamed the company Belridge Enterprises Pty Ltd (Belridge). Belridge commissioned a redevelopment study aimed at recommencing mining and processing operations. As part of the redevelopment study the authors planned a drilling campaign, managed a quality control program and developed a block model. This paper describes the drilling program, analytical procedures, quality control procedures and the preparation of the block model.The block model for the resource estimate was created using 1 m high blocks, wireframes defining the main material types, and 2.5 m thick horizontal search ellipsoids with a radial pattern. The deposit was ‘flattened’ prior to modelling. To assist with the economic evaluation of the project, each block in the model was assigned a net dollar value based on economic parameters provided by Belridge, including anticipated revenues and costs. This modelling technique allowed for efficient investigation of various scenarios and was used extensively in the development and optimisation of the project’s financial model. At a zero net value per block, comparable to a break-even cut-off grade of four per cent ilmenite equivalent, the Indicated plus Measured resource is estimated at 51 Mt, averaging 4.1 per cent ilmenite, 1.9 per cent apatite and 2.5 per cent titano-magnetite.

Oct 5, 2011