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Banks' focus in using cash flow methods can differ markedly from that of equity investors. This paper attempts to explain and describe bankers' approach by: ò outlining the fundamental difference between banks' and investors' risk / return profiles. ò describing lenders' consequent use of cash flow methods in mineral valuation. areas. explaining lenders' specific treatment of key risk Fundamental to understanding banks' appraisal of mineral projects is the appreciation that lenders have a basically different risk profile and outlook from those familiar to equity investors. Lenders do not normally participate in any project upside. The economics of lending dictate that banks can only accommodate a low probability of loan default and consequently banks' principal focus in mineral ""valuation"" is ensuring an acceptably comfortable probability of debt repayment. A simple conceptual explanation of lenders' risk / return position is outlined.

Jan 1, 1994

As has been the case since the early Phoenician traders, the minerals used by modern man come from deposits scattered around the globe. The price received is more and more being set by worldwide supply and demand. Thus the price component in the profit equation:Profits = Material sold (units)x(Price/unit û Cost/unit) is largely determined by others. The recent price history for two of the major metals, copper and iron, are given in Figures 1 and 2, respectively. As can be seen there has been a steady decline in the prices (when expressed in constant dollars) over the 20 years which have lapsed since the first of the International Conferences on Mass Mining, æDesign and Operation of Caving and Sublevel Stoping MinesÆ was held. If one would look back over the entire 20th century this would also be the trend. Cost containment/reduction through efficient, safe and environmentally responsive mining practices is serious business today and will be even more important in the future with increasing mining depths and more stringent regulations. A failure to keep up is expressed very simply as: Profit This, needless to say, is unfavourable for all concerned (the employees, the company, and the country or nation). The mining companies have had to look at ways of reducing the expense part of the profit equation while maintaining safe, environmentally conscious operations. Table 1 summarises the rules for working in todayÆs economy.

Jan 1, 2000

By B Davis, M Wallace, J Stewart, C F Burrett, J B. Cannell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Sepon district in Lao PDR contains 1.8 Mt of JORC (2012) compliant contained Cu resources in addition to >4.5 Moz of Carlin-like Au in a Palaeozoic sedimentary package. The Cu deposits are proximal to an EW lineament of Permian rhyodacite porphyry (RDP) intrusive centres that are characterised by intense barren quartz stockworks. The Khanong deposit (42 Mt at 3.0 per cent Cu mineral inventory) is a carbonate replacement intermediate sulfidation deposit verging on a high sulfidation environment, where abundant pyrite, copper sulfides (chalcopyrite, bornite, trace enargite), copper sulfosalts (including tennantite – tetrahedrite, colusite), and base metal sulfides (sphalerite and galena) have replaced low dipping dolomite and limestone layers, forming a manto-style orebody fed by steep dipping intensely silica-pyrite altered structures. The Thengkham deposits (54 Mt at 1.5 per cent Cu) are composed of prograde skarns (garnet, clinopyroxene) and mineralised retrograde skarns (chlorite, magnetite, hematite, epidote, sericite, talc, serpentine, carbonates, sulfides) which are irregularly and semi-continuously distributed around an elongate 4 km long intrusive centre. Thengkham and Khanong have been strongly supergene enriched, forming secondary chalcocite breccias and exotic malachite zones.The Carlin-like Au deposits display a range of stratigraphic and structural controls and lie outboard of the Cu deposits. Similar structural controls, alteration assemblages and trace mineralogies suggest that gold and copper mineralisation are temporally and genetically related. It is hypothesised that the differences in style of Cu and Au deposits across the Sepon district are related primarily to palaeodepth and proximity to the intrusive centres.CITATION:Cannell, J B, Stewart, J, Williams, P, Wallace, M, Burrett, C F and Davis, B, 2015. The Sepon copper deposits (Laos) and their relation to Carlin-like gold mineralisation, in Proceedings PACRIM 2015 Congress, pp 399–408 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By E L. Kotova

Completeness of extraction of a mineral from ore depends on many reasons. First of all it is a function of quality of disintegration of ore. It is supposed that two basic factors: character of structure and texture of the ore aggregate and a disintegration technique influence the quality of the mineral aggregate destruction, æopeningÆ of its internal boundaries. In this paper, the problem of technological mineralogy from the point of view of genesis of the mineral aggregate, its typomorphical features and methods of their quantitative description are discussed. The purpose of this research is to provide information for technologists. It should enable the development of a rational flexible scheme of disintegration of ore with full extraction of a useful component, without its losses and without unnecessary expenses of energy. For achievement of this purpose the mineralogical information should have ½number and a measure+. By the authors, the technique of the quantitative analysis of fabric of the mineral aggregate based on several models û thermodynamic, crystallographic and geometrical is offered and discussed. The leading role in the quantitative analysis of a fabric of ore belongs to internal bounders. But internal bounders of the mineral aggregate by bounders or faces of the mineral individuals or mineral grains are formed. Their geometry, orientation concerning own (mineral grain) crystallographic lattices, orientation and distribution in space of the ore aggregate are proportional to the energy accumulated at origin and the further growth. These characteristics of mineral individuals are consequences of conditions of their formation. That is why the named triad of models is used. From crystallography it is known that faces of different stability and mobility form borders of crystals. They also contain different quantity of energy. Mineral grains also are faceted by different energy borders. They form intergrowths with each other according to a principle of balance or unbalance. That is why in addition to traditional parameters of the description of a fabric of the mineral aggregate (mode and grainmetrical composition) it is necessary to add new. For example, length and the square of intergrowthing bounders of mineral individuals differentiated (in couples), crystallographic symbols of borders, their roughness and so forth. Consequently, solving a problem of the geometrical characteristic of borders, we define also its power characteristic. In this paper experience of application of our technology in studying ores of one of deposits of Urals Mountains is presented. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices, which are carrying out the analysis in a semi-automatic mode, are possessed. Structure and texture of rock or ore aggregate reflect its formation and transformation conditions. It is important to understand that disintegration energy cannot be more than aggregation energy, the energy of intergrowths formation. The square and orientation of mineral individuals borders vary at pressures or stresses of mineral aggregate evolution. These phenomena often cause selective increase in the square of borders at constant average grain size, ie the granulation. Granulation presents the increase in quantity of mineral individuals while their modal share remains constant. At the same time their average mineral grains size. Some mineral individuals increase in size at increased pressure. When lithostatic or lateral pressure drops the majority of mineral grains increases in volume at the cost of intersticial or film solutions or fine grains. These are only special examples of the ontogenesis of the mineral aggregate. They illustrate our statement that all changes in fabric of the mineral aggregate are a reaction on varying external (ie geological) conditions. It is possible to consider that structurisation of totality of mineral individuals as a whole is a process of adaptation of the mineral aggregate, which forms and exists in varying force and energy fields. Differential and integrated geometry of total internal boundaries of the mineral aggregate serves as adaptation mechanism of the mineral grains system. Boundaries form intergrowths of the mineral aggregate. Thus, it is possible to consider that the most informative parameters of the stereometric analysis for restoration of the ontogenesis of the mineral aggregate are the following. First of all, it is a quantitative estimation of the volumetric shape of the ore mineral in crystallographic coordinates, a total area of borders of all mineral grains in the aggregate, the specific square of their boundaries, the specific square of intergrowth boundaries of the ore mineral separately with grains of each minerals of the matrix of the mineral aggregate as well as traditional grainsmetric and modal composition. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices that are carrying out the analysis in a semi-automatic mode are possessed.

Jan 1, 2008

Carbon sequestration in planted forests provides an immediately available, low cost option to address the greenhouse impacts of coal mining and coal utilisation in a carbon constrained world. In addition, planted forests also offer the opportunity to address other environmental issues, particularly salinity and loss of biodiversity. Given salinity is characteristically associated with agriculture in the 500 to 700 mm rainfall belt, then where such forests can also produce commercial timber products, they offer the additional opportunity to establish new, diversified rural employment in both timber growing and processing. In the majority of Australian catchments affected by salinity, where rainfall is generally less than the 700 mm limit to conventional forestry, and where groundwater reserves are often saline, the objective of achieving economically viable forestry production presents a significant challenge. In 1996, Saltgrow commenced a collaborative breeding program to combine the salt and stress tolerance of E camaldulensis, with the growth rate, stem form and wood properties of the commercial species, E grandis and E globules. This program aimed to produce trees with the potential for commercial rehabilitation of saline landscapes. Results covering a range of site conditions from SaltgrowÆs network of over 100 trials around Australia are presented. The opportunity for commercial plantations integrated with agriculture in low to medium rainfall areas to address salinity and sustainability will be discussed. In addition, the significant potential for partnerships between land-rich, cash-poor farmers, catchment management authorities seeking to invest in public good projects that enhance environmental sustainability, and major carbon producing industries with either mandated or voluntary requirements to curtail net emissions will also be discussed.

Jan 1, 2005

In order that the processes seen may be followed in their proper 'order, the subject will be dealt with as follows, (1) Wallaroo and Moonta Mines; (2) Wallaroo and Moonta Mines Smelting Works; (3) Broken Hill Mines; (4) Concentration at Broken Hill; (5) Smelting and refining of Lead, Silver, and Gold at Port Pirie. The first acquaintance with the copper region was made at the Yelta shaft and dressing mill of the Parramatta Copper Mines Co. at Moonta. The country rock at Moonta is a hard, tough, felsitic porphyry, the copper lodes having a general strike of N. 30° Kilipping from 500 to 70°. This necessitates shaft-sinking on the lode, and underlay shafts are the rule on the field. The ore is raised in the Yelta shaft in wheeled skips, and consists of ·chalcopyrite, bornite, pseudomorphic hematite, containing, in addition, molybdenite and tourmaline. The ore from the bins at the brace is passed over a grizzly; the over-size is hand-picked into smelting ore, concentrating ore, and waste rock (00 attle ), which is sent below for filling. The under-size is elevated to a trommel having in. holes. The over-size falls on to a picking belt made up of lengths of rope strapped with iron, working over wooden pulleys.

Jan 1, 1907

By J Millard, K Sexsmith

BHP Billiton Diamonds Inc (BHPB) has been mining kimberlite from several pipes at the Ekati Diamond MineTM located 300 km north of Yellowknife since 1997. Processing of kimberlite produces coarse kimberlite rejects (CKR, 0.5 to 8 mm) and fine tailings (less than 0.5 mm). The CKR are trucked to the Coarse Kimberlite Reject Storage Area (CKRSA) located within the drainage area of the tailings impoundment (Long Lake Containment Facility û LLCF). The coarse rejects are wet when dumped and are expected to freeze as a result of annual average site temperatures of about -10¦C. Seasonal thawing occurs along the exposed edges of the pile. Monitoring of the CKR indicates they have consistently low sulfur concentrations (0.4 per cent) accompanied by high acid neutralisation potentials (78 to 337 kg CaCO3/t). Carbonate concentrations vary from 0.9 per cent to 3.4 per cent. The CKR are therefore not potentially acid generating based on conventional laboratory testing. Monitoring of stagnant pools on the tundra downgradient of the CKRSA has shown that water originating from the pile resembles acid rock drainage (ARD). Water pHs can be less than 4, and sulfate concentrations are typically in the thousands of milligrams per litre. Conventional flowing toe seeps are pH neutral but also have elevated sulfate concentrations. Investigations conducted in the summer of 2002 revealed no evidence of in situ acid generation. Pore water chemistry is probably controlled by oxidation of fine-grained pyrite, neutralisation of acidity by calcium and magnesium carbonates and silicates, and freeze concentration of pore water. The acidity observed in tundra pools downgradient of the CKRSA appears to be a result of leaching and mobilisation of iron under reducing conditions at the CKR-soil contact. Downstream of the CKRSA, reduced iron oxidises and is hydrolysed on contact with the atmosphere causing pH depression. BHPB is applying the findings of this study by constructing facilities containing kimberlite on granite pads. These in turn are placed on frozen ground so that the foundations remain frozen and limits contact of wastes with the acidic soils.

Jan 1, 2003

Process engineering principles are used to analyse the features of leaching processes for large masses of low grade, unprocessed ore. Different performance characteristics are related to the numerous variants of these processes. The variant for which reagent enters a heap only via the input solution is further subdivided into three modes of operation. The three modes may occur in testwork and full-scale operations; the effects of process variables on the rate of the process are completely different in each mode. The mode can be identified by the time at which reagent first appears in the pregnant solution. It is related to the ratio of the height of the heap and the thickness of a band of ore in which the reactions are localised. Synthesis of the phenomena occurring within a heap via a computer program has produced a quantitative relation for the reaction band thickness. The program has been validated for several different systems. The overall achievement is that the mode of operation and the rate of the process can be forecast before column testwork is commenced. Some applications of the outcomes to testwork, process design and operational tactics are described.

Jan 1, 1994

Lithocaps are potentially voluminous zones of advanced argillic and associated argillic alteration located above the subvolcanic intrusive environment. They constitute exploration objectives for epithermal and porphyry-type deposits. High-sulphidation epithermal deposits may be sought within lithocaps, whereas low-sulphidation deposits may exist on their edges. Porphyry Cu-Au/Au deposits may be accessible beneath lithocaps if systems are telescoped sufficiently. Oxidation of the basal, pyritic parts of lithocaps may promote supergene sulphide enrichment under appropriate tectonic and climatic conditions.

Jan 1, 1995

By W Z. Liu, Q Q. Shi, H T. Yang, X L. Zhang

In order to improve the cutting blasting effect of dimension stone mining, the water coupling directional cutting blasting technology was put forward. Based on the test apparatus and special charge configuration, the mechanism of directional cutting blasting was analysed. Directional device changes the initial equilibrium of the total energy of shock wave effect on blasthole wall. The initial directional crack first appears in the blasthole wall that makes contact with the directional device. Then, two cracks are connected along the direction of the blasthole centre line under the action of detonation pressure and water wedge. The plexiglass tests showed that water coupling directional cutting blasting technology produced cracks along with the predetermined direction completely. The cutting surface was smooth and only a few short cracks appeared around the blastholes. It proved the validity of this technology.CITATION:Liu, W Z, Zhang, X L, Yang, H T and Shi, Q Q, 2015. Directional blasting rock cutting technology, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 815–818 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The Taupo Volcanic Zone in New Zealand and the Philippine Mobile Belt in the Philippines are characterized by active subduction, active volcanism and high seismicity. The main factors affecting characteristics of geothermal systems in both countries are: tectonic setting, source magmas, maturity of the systems, and depth to the degassing magma body. Within New Zealand, geothermal systems are grouped into arc- and rift-type. Fluids in arc-type systems contain high amounts of volatiles (40%) and higher Cl contents (3,000-10,000 mg/kg). Maximum temperatures are also higher, reaching up to >400¦C. Arc-type alteration assemblages in New Zealand and the Philippines are similar. Because Philippine geothermal systems are less mature, have higher temperatures and steeper geochemical gradients than New Zealand ones, advanced argillization is more widespread occurring down to depths of 2000 m. Mineral phases are more varied due to the active input of magmatic waters and the formation of vapor conditions at depth, forming P04-, B-, Li-, Ce-, F-, and Cl-bearing minerals at high temperatures. In the Philippines, high temperature magmatic-hydrothermal to contact metamorphic assemblages containing biotite, amphiboles and pyroxenes are relatively common, but rare in New Zealand.

Jan 1, 1995

By Kapoor M. L

EMF measurements were performed in the temperature range of 933-1095 K to determine the thermodynamic properties of oxygen dissolution in liquid lead and lead-tin alloys with tin in the dilute concentration range of 0 to 6 atom per cent. The oxygen in the Pb-O system was varied by equilibrating with (PbO) slag, and that in the Pb-O-Sn system was varied with the addition of lead oxide. Wagner's interaction parameter approach was used to evaluate the self interaction parameter and ternary interaction parameters at different temperatures, to yield: E8(pb) = 97.35 - 113.27 x 103/t Eo(pb) = 139 - 20.616 x104/1' Quasichemical formulation was employed to yield Inf to reveal the effect of tin on oxygen in lead. Results have been predicted on the basis of classical models and those obtained using the QCT approach of Alcock and Richardson at Z=2 have been found to agree with the experimental Data.

Jan 1, 1992

Cyanide-extractable gold is far more meaningful in the definition of ore, and control of extraction, than fire- assayable or aqua regia digestible gold. The use of cyanide- extractable gold addresses the significant problems of over- as well as under-assaying by fire and aqua regia digests. The problems of conventional control or diagnostic cyanidation extractions: lengthy extraction, and masking by pregrobbing in cyanidation extractions for assay purposes; are surmounted with a novel activator - Leach WELL. Full extraction of liberated gold, insignificantly affected by preg-robbers, can now be achieved within 30 minutes. This can assist in reducing common gold losses presently often hidden by inappropriate mine call factors, and/or high grade cut values. This paper includes a discussion of fundamental mechanisms of cyanidation, preg- and assay-robbing, which underlie the phenomena Involved.

Jan 1, 1992

Nauru Phosphate, which is one of the world's highest grade deposits discovered to date, contributed in 1969, 2.2 million tons of the total world production of 77.7 million tons. Phosphate production, which is the major source of revenue for the island nation, is carried out by the Nauru Phosphate Corporation, headed by a Government appointed Board of Directors. The complete mining operation, including ship loading techniques, is discussed along with proposals at present being investigated to upgrade the Quality of the product.

Jan 1, 1971

The Kaltails Project is situated close to the city of Kalgoorlie-Boulder in Western Australia. Located on the south-eastern fringe of the Golden Mile, Kaltails has been in operation since June 1989. The tailings forming the reserve for Kaltails have been derived from 100 years of underground mining on the Golden Mile, but, some of the re.;erve has been retreated in the past. A map of the tailings reserves and treatment plant site is presented as Figure 1. The gold project is a joint venture between Poseidon 90 per cent and Gold Corporation (ten per cent) and is managed by Poseidon Gold Kaltails.

Jan 1, 1992

By Griffiths L, Marshall P

fhis paper describes investigations into drainage of gas from the solid to control outbursts. Initial studies conducted on drainage of shear zones showed that, given enough time, these can be successfully drained. Once drained, they can be intersected and driven through without any activity of outbursts. The results of programme of investigations to determine parameters for drainage from the solid show that gas flow rates from the Bulli Seam on the average are about 2 litres/min/metre length of borehole. But when shear zones are intersected, the flow rates could be as high as 8 litres/min/ metre length of hole. Shear zones can be picked up from pressure measurements 50 - 60 m away and this could give sufficient time to drill through these zones and drain them in advance. Systematic drainage of Bulli Seam at West Cliff Colliery could eliminate or reduce frequency of outbursts considerably. At present drainage holes are being drilled systematically in the seam, with drainage installations on the surface. Gas purity of 80% methane is being delivered at the surface plant.

Jan 1, 1980

The main features and recent developments in the processes of benefication and extractive treatments of tin ores are reviewed. The need for development of processes to recover fine tin, tin from low-grade complex ores and from hard rock resources is indicated. The progress in understanding of slag-metal interactions and developments of fuming processes on industrial scale is delineated. the processes and prospects of hydrometallurgical and chlorination methods are briefly indicated.

Jan 1, 1992

By Kazis JV

The beneficiation of fine coal has been the major problem facing the coal preparation engineer in recent years. The influence of clay slime, particle size and reagent type are but a few of the many factors that affect the recovery of fine coal. Laboratory test work has indicated that substantial increases in recovery could be achieved by improvements in technology in all these areas. Unfortunately, in most cases this technology has not carried through to the operating plants.

Jan 1, 1984

By Sutherland R. A, Rawling K. R

The Nanisivik Mine is located 750 km north of the Arctic Circle at the north end of Baffin Island in the Canadian High Arctic, and has been in production since 1976. The paper describes the regional and local geology and the current mining and mineral processing operations, including recent innovations in each area. The Nanisivik zinc-lead deposits comprise Mississippi Valley type sulphides in a block-faulted sediment sequence of Proterozoic age. The deposits formed in two mineralizing stages by replacement of the carbonate host rock. Exploration techniques adapted to the permafrost environment include high frequency EM and ground probing radar. Core drilling is done with calcium chloride brine but trials with heated flushing water indicate potential for cost reduction. The predominant mining method at Nanisivik is room and pillar. Cut and fill is used in some satellites to the main zone. Due to the permafrost, dry drilling is employed in the underground mining. The permafrost enhances ground stability, permitting large underground openings and, as a result, the use of relatively large scale mining equipment. For power conservation, a remote control system for the ventilation fans has reduced mine power costs. The milling of the simple coarse-grained ore in an arctic environment requires special techniques in the design and operation of the plant for materials handling, utilisation of waste heat, reagent selection and tailings disposal. Regulated heavy metal contents in effluents discharged to the sensitive environment are achieved by natural processes. A recent change from sub-aqueous disposal of tailings to beach type deposition within a cell in the tailings area is reviewed. Planning closure of the property presents special problems and an opportunity for innovative techniques. Approximately 25 per cent of the employees at Nanisivik are drawn from the Inuit population of the Canadian Arctic. As the first permanent industrial activity in the High Arctic some innovative approaches to employee relations were required which have resulted in a very stable, culturally mixed community in a remote location.

Jan 1, 1993

Supergene nickel sulphide ore mined currently by Agnew Mining Company is at times partially oxidised to sulphate. The resulting soluble nickel, and calcium and magnesium in mill water, are shown to act as depressants in flotation. The depressant effect is favourably selective in that violarite, the main nickel mineral, is less affected than pyrrhotite. Nickel recovery, however, is adversely affected, probably through reduced flotation of complex sulphides. Soda ash consumption is increased markedly by the presence of the cations as shown by operating data and pulp titration tests. A significant increase in concentrate grade, from 9% to 14% Ni, was achieved late in 1981. One of the changes in plant practice which contributed to this improvement was the addition of soda ash to mill feed rather than to flotation feed as before. It is shown by laboratory tests that this reduced the depressant effects of the cations, thereby improving recovery at the expense of rougher selectivity, or equivalently, increasing concentrate grade at constant recovery. The selective depressant effect cannot be exploited until scavenger recovery is improved and a scavenger concentrate regrind-retreat äcircuit is implemented. Development is

Jan 1, 1978