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By M. Pearson, W. Bristowe, A. Hanson

"There's no such thing as quality assurance; only quality control ... by inspection. "(1) A common misunderstanding in the procurement and construction of custom designed, fabricated pressure vessels and piping systems is that quality assurance can be achieved by simply referencing codes, standards, ISO 9002, QMS or other such programs in the contract documents. In the authors' experience, nothing could be further from the truth, not detrimental to the performance of the equipment than the exclusion of inspection activities and reliance upon warranties and "fit-for-purpose" clauses. Likewise, the expectation that fabricators, suppliers, or third party inspectors can provide such assurances is also unrealistic where they have limited knowledge of the process, material selection criteria, or limited technical resources. The development and successful execution of a quality assurance program is a collaborative effort by engineers, designers, material suppliers, equipment fabricators, and field inspectors with the full understanding and support of the end user.This paper presents an outline of the quality control activities undertaken by the authors for several recently completed and on-going hydrometallurgical projects. The activities include: prequalification of fabricators and sub-vendors, shop audits, material validation testing, material source control and verification, positive material identification of weld metal overlay, specialised welding inspection, contamination control for titanium and titanium-clad fabrication, eddy current and mass spectrometer (helium) leak testing of shell-and-tube heat exchangers, hot cycle testing of titanium clad equipment, tolerance verification for refractory lined equipment, final inspection and cleaning.

Jan 1, 2004

By Resta S. A

Energy Resources of Australia Ltd - Ranger Mine is located about 255 kilometres east of Darwin in the Alligator Rivers Region of the Northern Territory. The Ranger project is surrounded by Kakadu National Park which is on the UNESCO World Heritage list. . Ranger Mine operates the largest uranium mine and processing plant in Australia. It is designed to produce 3000 tonnes of uranium oxide per year, but presently is producing a little less than one half that figure due to the depressed uranium market. The safety performance of the employees and Ranger as a whole continues to improve. The lost time injuries (LTI) have significantly reduced from 74 in 1985 to five in 1994. The total days lost due to LTIs have gone from 1543 to 14. These significant improvements have reflected directly on workers' compensation premiums in which a four-fold reduction has occurred. It is estimated that the actual monetary saving to the company is about $1.3 million per year and directly reports to the profit of the company. There is also an obvious and significant reduction in the less quantifiable costs such as the suffering of the injured employees and cost to society. The paper will review the various initiatives introduced and assess their effectiveness. Performance improvement is primarily dependent on the commitment, introduction of various initiatives and the subsequent change in workplace culture.

Jan 1, 1994

By W Newns

This paper describes laboratory and in situ tests and determines a set of parameters for stiffness and strength properties for a weak sedimentary rock mass, the East Coast Bays Formation of Auckland. The parameters derived are discussed in relation to peak strength and in respect of deformation limits associated with sequential excavate and support (SEM) or conventional tunnelling.

Mar 8, 2011

By PETER ROBINSON, KEVIN BARBER, OLIVER WHATNALL

The investigation and uptake of filtered tailings continues to grow around the world, but cost and scalability are deterrents for mining companies. Filtration technology that is currently in use is unable to meet the needs of many operations and projects that would otherwise adopt filtered tailings. For tailings to reach the desired moisture content for dry stacking, the majority of processes require pressure filtration, with significant upfront and ongoing maintenance costs. Given the comparative lower costs associated with low-pressure Viper vacuum belt filtration, this technology has the potential to alleviate dependency on high-pressure applications and make efficient dewatering and handling of tailings a more economic and sustainable solution.

By S Das

Deposit-10/11A is situated in the iron rich Bailadila region of India comprising haematite ore of average grade 65 per cent Fe. The deposit production line was commissioned in the year 2002 having a capacity of 5 Mt/a. The plant has the state of the art mineral processing equipments.The ore is transported from mines to crushing plant by means of dumpers. The ore is comminuted in two stages to get 150 mm top size product and this product is transported through conveyor system and is stored in silos as feed stock for beneficiation plant. In the beneficiation plant this crushed product is wet screened in two stages to produce a product of lump (-150 + 10 mm) and fines (-10 + 3.15 mm). The product of -3.15 mm top size is fed to primary classifier for a size separation at 150 µm. The resultant product (-3.15 mm + 150 µm) is dewatered and transported to fi ne ore product stock yard through conveyor system. The minus 150 µm material from classifier overflow is fed to cyclones (508 mm cyclone battery with an apex of 65 mm) for desliming at 45 µm and to recover ultrafi nes (-150 + 45 µm). The cyclone overfl ow slimes (-45 µm) along with water is treated in lamella thickeners to recover process water. The thickener underflow material is transported to tailing pond (discharge rate is 300 m3/h at a specific gravity of 1.4) by pumping through HDPE (high density poly ethylene) pipeline and the over flow water is being recirculated. The water requirement for beneficiation is approx 1.5 m3 per ton of ore.This paper aims at identifying and quantifying the factors that affect the overall plant performance (grade and recovery) during the different seasonal variations especially in the rainy season (mid-June to end October). The effect of seasonal variations on unit operations such as milling, classification, thickening and filtration are discussed. Specific cases are presented as examples and recommendations are formulated.

Jul 11, 2011

By E J. B van Etten

Pit lakes may form when open cut mining leaves a pit void that then fills with ground and surface waters. This often replaces terrestrial ecosystems that existed prior to mining with an aquatic ecosystem, affording an opportunity to improve regional aquatic biodiversity values through targeted aquatic restoration (McCullough and van Etten, 2011). Restoration theory provides guidance when restoring disturbed systems towards landscapes that are of regional value and relevance. But how do we identify a restoration target for a novel aquatic habitat that only exists in the new post-mining landscape? This paper presents a process of first identifying and then surveying local representative aquatic systems, to provide a direction for pit lake restoration efforts and achievement criteria for pit lake relinquishment, using a case study from a sand mining operation amongst wetlands in south-western Australia.The company mines silica sands following mechanical removal of topsoil and then extraction of the ore from below the watertable by dredging. Assessment of wetland and riparian vegetation was achieved through the establishment and measurement of temporary monitoring transects across five natural wetlands in the Kemerton area. Several more regional wetlands were also visited and observations made to supplement and validate these data.Distinct vegetation zonation was found across each wetland, although typically wetland basins were unvegetated or filled with younger woody plants with patchy distributions. Fringing riparian vegetation consisted of few species (commonly the paperbark Melaleuca rhaphiophylla and the sedge Lepidosperma longitudinale), but community composition and structure were variable between wetlands. The pattern of vegetation seen across natural wetlands was best explained by topography and soil chemistry, with low lying wetland areas more likely to experience regular flooding and accumulate organic matter and nutrients.In conclusion, where they are available, regional natural waterbodies may constitute the best valid restoration goal. Nevertheless, the goal may need to consist of a range of closure design opportunities, rather than a single target.

Oct 5, 2011

By D Laurence

Australians are at the forefront of exporting their mining expertise in a number of areas. Minerals education is just one example. The growing economies of Southeast Asia host some of the most prospective mineral fields in the world. Laos for example, hosts the world class Sepon and Phu Kham copper-gold deposits. The Philippines has the fifth largest global mineral resource inventory. These and other countries in the region lack the mining engineers, geologists and metallurgists required by international mining companies to ensure their operations are sustainable. This paper describes the author’s experience in working with mining schools in Southeast Asia and specifically the Philippines, Cambodia, Laos, Thailand and Vietnam. Various strategies to ensure sustainability and lessons learnt are presented.

Nov 22, 2011

By D Connelly

Silver and gold bearing ore from the Troy Resources NL Casposo Gold-Silver Project, located within the San Juan Province of Argentina contains a complex mix of gold, silver, electrum and silver sulphides in the ore. Casposo is a typical low sulphidation epithermal style gold–silver deposit where mineralisation is hosted within rhyolite – andesite flows and breccias. Veins are typically banded quartz–chalcedony colloform - crustiform banded with quartz - carbonate infill. Mineralisation is associated with an assemblage consisting of quartz, chalcedony, adularia, calcite, illite, sericite and trace sulphides. Gold and silver occur as electrum, native silver, sulfosalts and silver sulphides. This paper presents a case study that describes the process selection, development and engineering of a tailored process plant for the recovery of gold and silver from this ore.The original feasibility study, modelling, metallurgical testwork and engineering studies are outlined. The final flowsheet was based on minimising capital cost, operability, recovery and minimising technical risk.The process flowsheet uses the traditional Merrill Crowe route because of the high silver to gold ratio in the feed and achieves maximum gold and silver recovery while providing a common facility for future ore body treatment.

Aug 8, 2011

By R Fletcher

Pacific Hydro, a leading renewable energy company from Australia, is developing a series of cascading run-of-river hydro electricity projects in the Cachapoal Valley at the base of the Andes Mountains some 100 km south of Santiago in Chile.These projects involve extensive tunnelling and underground works. The first of these projects is called Chacayes (110 MW installed capacity) and is now under construction with Astaldi SpA of Italy and Fe Grande of Chile as the EPC contractor. Astaldi SpA also has an equity stake in the project. It involves 6 km of tunnels between 5 m and 7 m diameter, of which 2.3 km is by tunnel boring machine (TBM) (5 m diameter).This paper outlines the local and regional geology, the scope of the Chacayes project, actual tunnel excavation rates and support, and compares the decision making on Chacayes between a choice of traditional drill and blast excavation versus TBM.The paper also outlines the next project planned to be developed by Pacifi c Hydro in the valley – the 140+MW Nido de Aguila project involving a main tunnel drive of 11 km with two intermediate adits, plus a 388 m shaft and underground powerhouse. The main tunnel drives are likely to be excavated by two hard rock TBMs (5 m diameter) but will need to be able to withstand high overburden pressures of up to 1300 m.Subsequent projects in the planning stages include the downstream Coya II project with two tunnels totalling approximately 10 km, one of which may be by TBM.

Mar 8, 2011

By Marton A

The Readymix Group have a Quarry Improvement Program - 'Building in Quality (BIQ) which has many parallels to the ICI Explosives' total quality management - 'Quality Improvement Program' (QIP). Both companies have for some time recognised that the 'do it right first time' principle means less wasted effort and materials, that efficiency breeds profitability and so actively promote the quality culture. To install the principles and generate the culture requires considerable commitment and effort from the top down and invariably spreads to the suppliers and sub-contractors. Understanding the component processes involved with the quarry operation, analysis of those processes and gaining a breakdown of the cost of non conformance then allows the astute quarry operator to make the necessary changes to improve the process to realise profits. This paper outlines the steps in such a process and the profitable outcomes of the commitment to continuous improvement at the Nickol Bay Quarry.

Jan 1, 1994

By M. Deniz Turan, HASAN NIZAMOGLU, Z. ABIDIN SARI, Tolga Depci

Chalcopyrite extraction in an aqueous acid medium occurs through solid transformations into distinct intermediaries. As intermediates, mineral phases CuS, Cu2 S and Cu5 FeS4 may generate in the leaching solution before CuFeS2 completely decomposes to Cu2+, Fe2+ and S0. Oxalic acid is a common organic acid, and it dissolves easily in warm water. Due to the chelating feature of oxalic acid, it hinders iron precipitation by composing soluble complex anions in a wide range of pH. In this study, recovery of copper from solid material (obtained by leaching of chalcopyrite with oxalic acid in the presence of hydrogen peroxide) with a copper oxalate structure was carried out selectively using hydrochloric acid (HCl). Selective recovery of copper by degrading the copper oxalate structure with a low-solubility product (Ksp= 4.43 × 10 −10) was performed by conventional leaching in the presence of HCl.

By K Morrison

Australia’s ageing population means that by 2050 there will be 2.7 people of working age to support each Australian aged 65 years and over compared with five working people per retiree today and compared with 7.5 in 1970 (Swan, 2010). This means that there is going to be a greater demand on social services – for medical and aged care – from a smaller private income base. How will this gap be met? Australia is fortunate in that it has vast resources of mineral wealth; from iron ore, nickel and gas in Western Australia to the giant copper and uranium deposits at Olympic Dam in South Australia.The prospect of a meaningful profit based tax on this vast mineral wealth has been lost through Australian government’s handling of the issue in 2010 and with an industry fiercely opposed to the prospect of a mining tax. Hence, new ways of thinking are required. This paper looks at the issues facing the implementation of a novel scheme whereby Australia leases the mineral resources it extracts and thus derives income over the decades the metals are in-use in pipes, wires and structures with a premium paid for unreturned material or that used in dissipative applications. Applicable minerals could include copper, aluminium, nickel and rare earths. If Australia simply digs up and sells the metals once, the buyer becomes custodian of that resource and they benefit from controlling the future ‘above-ground’ resource stock.A complementary driver for a leasing scheme is the increasing importance of chain-of-custody following initiatives of the Responsible Jewellery Council with gold and diamonds, now with the potential to extend across commodities. The Australian minerals sector could thus position itself as a premium supplier with high social and environmental credentials.Recognising the implementation challenges, this paper includes a review of how such a system could be enforced to ensure that the metal is tracked throughout its life. It concludes with a discussion of the rates and terms should such agreements hold and suggestions for institutional arrangements for enforcing compliance.

Nov 22, 2011

By A Fowler

The unpredictability of the location, grade and width of narrow-vein deposits presents difficulties for mine geologists and engineers attempting to estimate, schedule, forecast and mine their deposit profitably. This unpredictability stems not only from the grade distribution within a vein, but also the irregularity of vein geometry in three-dimensional (3D) space. Traditional deterministic methods of modelling vein geometry do not account for the inherent variability of the veins, resulting in significant errors when using limited drill hole information. This paper presents a probabilistic method of modelling narrow-vein deposits using sequential gaussian simulation (SGS), which can quantify this variability and improve production forecasts. Vein geometry, thickness and grade are simulated to provide a number of different equi-probable realisations that each honour the drill hole and face sample input statistics. An example is presented from the Augusta narrow-vein Au-Sb mine in central Victoria, where the simulation results are validated against the input data and survey pick-ups of the veins along ore drives.

Aug 22, 2011

By K Ehrig

Two irrefutable facts in geology and metallurgy are: ore deposits are comprised of variable mixtures of minerals which are systematically distributed throughout the deposit, and mineralogy exerts the primary control on metallurgical performance. If the distribution of process critical minerals can be quantified and mapped, then a logical assumption is that metallurgical performance can be predicted across the deposit.Olympic Dam is a +9 billion tonne Fe-oxide Cu-U-Au-Ag deposit which is hosted entirely within a magmatic-hydrothermal breccia complex consisting of over seventy ore and gangue minerals. Each has a unique set of metallurgical performance properties. Fortunately, 15 of the 70 minerals accounts for >98 per cent of the total rock mass.The mineral mapping journey commenced in the early drilling days shortly after the discovery of Olympic Dam in 1975. Geologists quickly recognised that the copper-iron sulphides had a predictable zoned distribution. However, geological models reflected the presence or relative abundances, not quantitative concentrations, of the minerals. This type of mineral mapping remained relatively unchanged for ~20 years and was of limited use outside of geology.Several things changed during the mid-1990s: assaying costs decreased significantly, instruments capable of automatically measuring mineralogy became readily available, the recognition of two quantifiable relationships at OD (ie mineralogy is a function of chemical composition (ie assays), and metallurgical performance is a function of assays, mineralogy, texture and process conditions. The linkage of metallurgical performance to mineralogy and mineralogy back to assays allows for every assayed sample in the resource model to be assigned mineral concentrations and metallurgical performance predictors. At Olympic Dam, block models (ie 3D maps) are routinely produced for 27 elements, density, 15 process critical minerals and greater than 50 metallurgical performance variables. These geometallurgy-enabled resource models are used for mine planning, process plant design and process optimisation studies. *This is an abstract only. No paper was prepared for this abstract.*

Sep 5, 2011

By C Lower

An unprecedented, quantitative, deposit-scale understanding of major clay mineral distribution throughout the Yeelirrie uranium deposit has been achieved by adapting the existing HyLogger™/HyChips™ analytical technique to measure resource assay pulps. Spectral analysis via HyLogger™ and HyChips™ systems has previously been used as a small-scale geometallurgical research tool, but never before has it been quantitatively applied to an entire resource sample population for the purpose of developing stand alone block models for major clay minerals. Economic uranium mineralisation within the thin but extensive Yeelirrie?palaeochannel?primarily exists within the transition zone between a groundwater-derived calcrete and the underlying clay-quartz regolith. Early geometallurgical investigations identified that certain clay minerals could be deleterious to the efficiency of the uranium recovery process. Accurate calculation of clay mineralogy from resource assays proved too difficult due to chemical similarities between co-existing kaolinite, smectite and magnesium carbonate minerals. A relatively low-cost, efficient and accurate method of quantitative clay mineral analysis was required to measure over 70 000 resource assay pulps. After initial testing and comparison with QXRD, the HyChips™ 3-1 spectral logging system was implemented as a primary method of clay mineral analysis for the Yeelirrie uranium deposit. The resultant spatial data set allowed the interpretation and geostatistical analysis of geometallurgical domains across the deposit. Clay block models were generated and used in geometallurgical resource calculations to benefit the mine planning process.

Sep 5, 2011

By Rameshwar Sah, PK GHORUI, LR SINGH, SIVALINGARAJU BARISETTY, SHYAM YADAV

Fly ash is a by-product generated by the combustion of coal in thermal power plants. Its disposal is a major environmental concern for these power plants. Though a considerable part of fly ash is used in cement making and brick manufacturing, a substantial quantity remains unutilized. Bentonite is commonly used as binder in the micropelletization of process waste to attain the mechanical strength required for handling and transportation. The present paper deals with the partial replacement of bentonite with fly ash in the micropelletization process without affecting the quality of the micropellets. The mechanisms of both the binders are discussed. The bonding of particles by bentonite is a physical mechanism, while fly-ash bonding is a chemical mechanism. Silica and alumina are the major constituents present in fly ash along with lime. In the presence of water, the alumino-silicates and unhydrated lime present in fly ash undergo a pozzolanic reaction and form cementitious bonds, which hold the particles together. Use of fly ash as alternative binder for bentonite has cost benefits besides providing a better utilization option for fly ash.

By Jim Smith, Jeff Hudreth, John White

Jan 1, 2000

By H. Hitchen

THE object of this paper is to present the various facts that l1ave been revealed during lengthy investigations into the performance of all types of ropes on different hoisting installations. It then goes on to suggest means by which most of these findings could be usefully employed to obtain more economical rope lives with increased safety. SHAFT HOISTING ROPES Four basic designs of ropes are now employed for hoisting duties: (1) Six-strand, round strand ropes with fibre cores. (2) Six-strand, triangular strand ropes with fibre cores. (3) Non-rotating, multi-strand ropes. 0) Locked coil ropes. Round Strand Ropes (Figure 1) Very solid and reliable ropes can be obtained with this simple geo-metric design of strand. 1'1?iangula1? Strand Ropes (Figure 2) Owing to the fact that the wires in the strands are bent over a triangle, they do not seat quite so solidly as when they are bent over a circular core wire, as is the case with

Jan 1, 1963

By EDER DOMINGOS OLIVEIRA, Leandro Viana Teixeira, Carlos Antonio Morais, Ruberlan Gomes Silva

Special attention must be considered in the production of high-grade rare earth products, such as mixed rare earth oxalates or carbonates. In the main minerals used industrially, the rare earth elements (REEs) are finely associated with impurities like calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe), aluminum (Al), thorium (Th), uranium (U) and phosphorus (P). Most of these impurities must be removed to avoid losses of rare earth oxides (REOs) as well as to prevent product quality degradation and low operational performance in the downstream steps of solvent extraction or ion exchange. The present study aims at investigating the conditions required to precipitate REEs, either as rare earth oxalates or carbonates, from purified rare earth sulfuric liquor with low Al3+ and UO22+ concentrations and very high Ca2+, Mg2+, Mn2+, and SO42− impurity contents.

By Andrews B. S

The sinter plant at the Sulphide Corporation's Cockle Creek works produces a feed for the company's Imperial Smelting Furnace. The feed contains lead and zinc oxides and all the fluxes necessary for furnace operation. The quality of this feed is a major factor in furnace performance and the considerable flexibility of operation possible at the sinter plant has been used in efforts to achieve optimum operating conditions.Operating data is processed daily and information gathered from this source has led to three of the four improvements described.These improvements have resulted from elimination of gas recirculation, reduction of sinter returns sizing and alteration of ignition conditions and main layer fuel loading.

Jan 1, 1964