Search Documents

By J Col, D La Rosa, W Valery, A Jankovic

Metso Minerals Process Technology Asia-Pacific and South America (MMPT) has been working with operations around the world to increase their efficiency through æMine-to-MillÆ or Process Integration and Optimisation (PIO) projects. These projects have delivered significant improvements in mine efficiency, mill throughput and reduced operating costs at mines around the world. The MMPT methodology involves rock characterisation, site auditing, data collection, modelling/simulation and implementation of integrated operating and control strategies on site. This results in significant benefits to the operations û for example, 5 to 20 per cent increases in concentrator throughput have been measured. MMPTÆs rock characterisation utilises simple and inexpensive measurements that can be performed by trained site personnel. The advantage of these measurements is that a large amount of data can be collected in a very short timeframe, as the samples do not require shipping to an outside laboratory. Typically, a PIO project starts with a site visit to perform blasting and process audits, collect high quality data including measurements of run-of-mine fragmentation and survey data around all crushing and grinding circuits. These measurements are combined with rock characterisation and the definition of strength and structure domains to model the complete production chain. Site-specific models of the blast fragmentation, crushing, grinding and flotation processes can then be developed. This proven methodology has applications ranging from greenfield projects to long-standing operations with AG/SAG or conventional grinding circuits. Process improvements can be higher mining productivity, higher mill throughput, decreased overall operating costs and higher flotation or leach recovery. This paper discusses a recent application of PIO conducted at a large open pit operation in South America and emphasises the potential that every operation has to ædo more with what they haveÆ.

Jan 1, 2007

Process mineralogy is an inter-discipline in the fields of mineralogy and mineral processing. As a predicting and trouble-shooting tool, process mineralogy helps address all mineralogical issues and problems related to mineral processing. It provides useful information on process design and optimisation, flow sheet development and cost reduction. As more and more complex and refractory ores are being discovered and processed, it is believed that process mineralogy will gain more attention and play a more important role in process design and optimisation. This paper will first discuss the scope of process mineralogy and mineralogical factors that may affect mineral processing of various ores, and then focuses on the application of process mineralogy in process design and optimisation through case studies.

Jan 1, 2008

By T Vizcarra, G Sandoval, C L. Evans

One of the challenges in the development of mineral processing simulators is modelling the liberation characteristics of particles produced by comminution circuits. Understanding the mineral characteristics of these particles is one of the keys to predicting their behaviour in separation circuits. While more fundamental research seeks to model the non-random breakage of ores this work examines whether we can move forward now by using observed characteristics of ores to model the composition of particles generated in comminution processes. Several researchers have noted the similarity of the liberation characteristics for a selected size fraction of particulate material, whether the fraction comes from a coarse material, such as the product from a jaw crusher, or a more finely ground material, such as the product from a ball mill. In most cases these observations were reported as an aside and were not the main focus of the published work. This observed behaviour has the potential to be a useful tool for modelling the particle characteristics in mineral comminution and separation circuits, particularly as we move towards the development of multi-component models. However, before the behaviour can be used widely we need to understand which ore types follow the observed pattern and which do not. The current work examines a range of ores and identifies which exhibit the pattern of similarity of composition for particles in a given size class that has been produced as the result of a variety of breakage conditions. The impact of mineralogy and texture on the evolution of liberation characteristics for both valuable and gangue minerals is discussed.

Jan 1, 2008

Most of the Ta-Nb ores in China occur in altered granites, and Ta-Nb minerals occur in these granites as accessory minerals. This type of Ta-Nb ores are characterised by whole mineralised granite mass, large reserves, low grade of tantalum and niobium, less economic minerals, complex mineralogy, difficulty in separation and concentration of Ta-Nb minerals and high operating cost of ore dressing. The Ta-Nb ore presented in this paper is a low-grade Ta-Nb ore occurring in altered granite in Jiangxi province. It has large reserves, with the grade of Ta2O5 0.013 per cent and Nb2O5 0.023 per cent. The process mineralogy study carried out by the authors determined ore mineralogy and ascertained occurrence of Nb and Ta and their mineral processing characteristics. The results are used as the guide for developing the optimum mineral processing flow sheet. The results also indicated that this type of Ta-Nb ore contains a high content of Li, K and Na, a low content of deleterious impurity Fe, and the tailings can be used as feed for glass and ceramic materials. This study provided important mineralogy information for exploiting and utilising low-grade Ta-Nb ore resources, developing a mineral processing flow sheet and further utilising the tailings.

Jan 1, 2008

Nickel ores from three different mines, Digger Rocks, Cosmic Boy and Flying Fox, are treated at the Forrestania concentration plant. The ore types vary from oxidised supergene ores to primary pyrrhotite+pentlandite ores. Mineralogical investigations on the ore and process samples have been carried out in different stages of process development. One of the studies was done with the samples collected from the flotation circuit in 19 June 1994 when the Cosmic Boy ore was processed. The process products were screened, and the size fractions were analysed for the main elements by appropriate analytical methods. Mineralogy of the products was studied microscopically and composition of the sulphides was analysed with an electron microprobe. Liberation of the main sulphides in the flotation feed was determined with the point-counting method, and weight percentages of the minerals were calculated using chemical and mineralogical data. The typical sulphide assemblage of the Cosmic Boy ore is violarite, pentlandite, pyrite, pyrrhotite and chalcopyrite. Violarite dominates over pentlandite (ratio being 70 per cent to 30 per cent), and pyrrhotite is strongly replaced with pyrite and magnetite. One of the most common mineralogical features of this ore type is secondary magnetite, which occurs as narrow rims in porous violarite or in association with secondary pyrite. Serpentine, talc and chlorite are the main gangue minerals. In the milled feed (76 per cent -74 ¦m) locked particles between nickel and iron sulphides are common. About 41 per cent of total pentlandite occurs as pure liberated particles, and 33 per cent as locked grains with violarite. Liberation degree of violarite is 55 per cent, and the most common type of locked particles is violarite+magnetite, carrying about 20 per cent of total violarite. To achieve a recovery of 80 per cent for pentlandite, all the particles containing at least 50 vol-% pentlandite should be floated into the nickel concentrate. Correspondingly recovery of 80 per cent can be reached for violarite if all the particles containing at least 65 vol-% violarite are floated.

Jan 1, 1996

The Manto Verde copper mine (Atacama Region, Chile) is due to go into production in 1996. It will produce 40 000 tonne/year of copper cathode by heap leaching/SX-EW. Mineralogical studies were undertaken in conjunction with the metallurgical testwork program to characterise the ore and its response to leaching by dilute sulphuric acid. The leachable copper mineralogy is dominated by the oxide copper minerals: brochantite and malachite with minor chrysocolla and atacamite. The gangue minerals include abundant orthoclase, specularite, quartz and chlorite with minor muscovite and trace smectite clay, calcite and limonite. The study showed that complete or partial decomposition of calcite, chlorite, smectite and wad consumed acid and generated solution impurities (Ca2+, Fe2+, Mg2+, A13+, K+, Si4+ and Mn4+2+ ). Although these were manageable at Manto Verde, their uncontrolled build-up could have affected the operation in several ways: the degradation of heap penneability and fonnation of crud in the SX plant from the precipitation of gypsum, goethite, colloidal silica and jarosite; and the entrainment of contaminated pregnant leach solution in the SX organic resulting in the transfer of impurities to the electrolyte and subsequent effects on cathode quality and electrowinning efficiency. In conclusion, process mineralogy played an important role in understanding and managing potential mineral-related problems in the heap leaching and SX-EW recovery of Manto Verde ore.

Jan 1, 1994

By E A. Agorhom, M Beyuo, C Owusu, I Quaicoe

Understanding the mineralogy and liberation of gold particles in an ore is key to the development and optimisation of gold processing operations, being cyanidation or gravity separation. This can be achieved through basic historic geological information, gold deportment studies, chemical speciation and metallurgical test works. The present study assessed the nature of the occurrence of gold particles (mineralogical composition, liberation, associations and surface chemistry) and its effect on the process route (cyanidation and gravity separation) of a typical paleo placer gold ore deposit within the Tarkwaian Rock system. The investigative approach used involved chemical assay, quantitative X-ray diffraction (QXRD) and quantitative evaluation of minerals using scanning electron microscopy (QEMSCAN). The ore samples (A, B, C, D, E, F) used were obtained from six active pits of a gold mine working on this orebody. The results of the mineralogical analysis revealed that the ore is highly oxidised and comprised quartz (>80 per cent) and Muscovite mica (>6 per cent) as the major mineral phases in all the samples. Trace amounts of hematite, kaolinite and todorokite were also identified in all the samples. The chemical analysis showed presence of gold (Au) in all the samples with samples B (3.62 g/t) and C (3.96 g/t) containing the highest concentrations. Trace amounts of copper (Cu), iron (Fe), sulfur (S), aluminium (Al), arsenic (As) were also detected in all the ores. The QEMSCAN mineralogical liberation and gold association results revealed that the gold grains were relatively coarser in all samples (P80 > 80 µm Au in size) except F (P80 < 32 µm Au in size). Gold grains were highly liberated especially in sample B with the majority of the locked gold grains forming complex associations. All the samples responded well to cyanidation and gravity separation except samples C and F, respectively.

Aug 24, 2022

By F Tang, Ö K. Büyükuslu, M Baben, S Petersen

GTT-Technologies’ ChemApp for Python was developed to provide a powerful, easy to use interface to ChemApp for a programming language highly popular with scientists and engineers. It is used, for instance, by GTT to develop program modules such as the CALPHAD Optimiser for the FactSage™ software, by customers to move from interactive FactSage calculations to perform versatile scripting with Python, and by GTT and its partners in research projects in the area of materials informatics. Computational thermochemistry is fundamental for advancing sustainable metallurgy and creating new alloy compositions for engineering applications. Materials informatics involves handling vast amounts of data and complex workflows. GTT’s approach uses ChemApp for Python and the FactSage thermodynamic databases to design recyclable alloys from the start, incorporating a higher percentage of scraps while aiming to simplify the workflows to simulate material design steps. Challenges arise due to recycling scraps, introducing more elements for consideration. CALPHAD-based databases accurately cover materials from primary metallurgy, but additional data for minority and critical elements is crucial for precise computational modelling. GTT combines machine learning-based ab-initio databases with traditional CALPHAD databases to cover the complete chemical space with appropriate accuracy. The design of a hardfacing alloy through a high-throughput materials informatics approach is used as a demonstrator of the current possibilities.

Jun 19, 2024

By J Mercuri, S Dunford, P Rothman, E Bartsch, J Snyder, D Newton, R Maron, D Cirulis

The purpose of a mineral comminution circuit with a ball mill running in closed-loop with a hydrocyclone classification cluster is to feed the downstream process with the target particle size. Maintaining the optimal particle size in the flotation feed can significantly improve plant cash flow. In particular, reducing the amount of coarse material is often a major challenge. Existing instrumentation to provide particle size measurement is considered standard equipment in most modern concentrator plants. However, availability is often very low, mainly owing to high maintenance requirements of the analyser and associated sampling system.CiDRA Minerals Processing has developed two novel and robust technologies that address this challenge by providing high reliability and very low maintenance systems for on-line measurement of coarse material in the overflow of individual hydrocyclones. The first system is non-invasive and measures pebbles and rocks greater than 6 mm. This paper focuses on the second system, which is a ruggedized wetted sensor design with no moving parts and provides a real-time trend of the desired target grind size parameter, such as percentage above 150 micron.Both systems have simple robust designs and measure in the primary overflow stream of the individual hydrocyclone. Individual hydrocyclone measurement enables identification of poor performing hydrocyclones in addition to providing a representative measurement of the whole hydrocyclone cluster. The systems do not require sampling and associated sample transfer piping circuits that are prone to plugging, thus avoiding high maintenance requirements.The wetted sensor will be described in detail along with its implementation in a robust control scheme in a major copper concentrator in North America. Plant data shows very high availability, achieved with very low maintenance, has enabled improved process control, thereby maintaining throughput and ball mill target power while reducing grind size.CITATION:Cirulis, D, Dunford, S, Snyder, J, Bartsch, E, Rothman, P, Maron, R, Newton, D, O’Keefe, C and Mercuri, J, 2015. Process optimisation using real-time tracking of coarse material in individual cyclone overflow streams, in Proceedings MetPlant 2015, pp 93–109 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Hampshire MJ

The tailing retreatment project rated at 10 000 t/day commenced operations in October 1982. The operation consists of dredging, feed preparation, cyanide leaching and carbon-in-pulp (CIP) gold recovery followed by Zadra atmospheric stripping and electrowinning. For the first two years the operation was adversely affected by excessive cyanide consumption and low gold extraction. Investigations demonstrated that the very fine, or slime, fraction of the tailing was the dominant consumer of cyanide and dissolved oxygen. The plant flowsheet was subsequently modified by inclusion of 80 - 100 mm dia. cyclones for slimes separation and a 31 m dia. thickener for water recovery. Treatment of deslimed feed in the CIP plant has reduced sodium cyanide consumption from an average 1.85 kg/t to 1.15 kg/t. The reduced oxygen consumption by the CIP plant feed has resulted in higher dissolved oxygen levels, frequently reaching supersaturation after 4 to 5 h contact time. This has allowed much improved gold extraction from the existing CIP plant capacity. Gold extraction from the mixed pyritic siliceous tailing has improved from an average U prior to desliming to a current 57%. Investigations are continuing on the recovery of gold from the discarded slimes.

Jan 1, 1986

Process Options for Difficult Arid-Region Nickel Laterites In the absence of the discovery of significant nickel sulfide deposits, the future of Australia&apos;s nickel industry will increasingly depend on cost effect processes for low-grade nickel laterites. The problems encountered with the West Australian HPAL plants, resulting in three of the four plants being shut down, have caused the industry to revisit atmospheric leaching options, particularly heap leaching. West Australian laterites are characteristically very varied in grade, chemical composition and mineralogy with the result that, thus far, one process does not fit all laterites. In this paper the leaching of an especially refractory ore is compared using column leaching of whole ore and atmospheric leaching and HPAL processing of ground ore. The key characteristic is the resistance of the goethite phase to acid attack with low-to-moderate temperature leaching conditions. The refractory characteristic is attributed to the stabilising influence of chromium and aluminium and possibly manganese substitution in the goethite crystal structure and goethite morphology. A significant three-fold increase in both nickel and cobalt extractions under atmospheric leaching conditions was achieved by the relatively simple modification of bubbling sulfur dioxide into the reaction vessel to create a reducing environment. Recoveries increased from &lt;30 per cent to 90 per cent nickel and 86 per cent cobalt after 10 hours of leaching at 95¦C. An even greater improvement was achieved under ambient conditions by heating the ore to temperatures above 250¦C for 30&nbsp;minutes. Subsequent leaching at ambient temperature gave an eight-fold increase in both nickel and cobalt recoveries after 14 days bottle rolling. Both methods could be optimised and implemented in such a way as to increase laterite reserves in conjunction with a heap leach operation but may be better suited to vat or closed tank processing.

Sep 13, 2010

The treatment of nickel ores and concentrates and the subsequent processing to recover separate products of nickel and cobalt is one of the major interests at present in the mining industry. The increasing demand for nickel, and more recently also cobalt, has led to increased exploration for ore sources. Major discoveries have resulted in Canada and Australia. These deposits, as well as others already known, are presently being developed and the process technology tested and evaluated for applicability to the different mineralogical types - mainly sulphide, arsenide and oxide laterites. Concentrates may be treated by either hydro- or pyrometallurgical processes, while the nickel laterites are best suited to hydrometallurgical processing. However, if hydrometallurgy is used, once the ore or concentrate is leached the resultant solutions are then amenable to similar separation technologies for purification and recovery of high purity nickel and cobalt products. Solvent extraction, together with other separation processes such as precipitation, can produce high purity solutions of nickel and cobalt. The final products of these solutions may be nickel and cobalt cathodes, metal powders precipitates or salts, depending on the final process of electrowinning, hydrogen reduction, precipitation, or crystallisation Respectively.

Jan 1, 1996

By Warner N. A

There is an inherent problem in producing simultaneously lead, zinc and copper as metals in a single polymetallic smelting furnace. It relates to the condensation of lead and zinc from the gas phase under vacuum conditions such that metals in bulk form, either solid or liquid, are obtained as products rather than a fume or dust containing both metallic and non-metallic components. To understand this phenomenon, it has been necessary to establish mathematical models with computer simulation to identify the process requirements for effecting the objective of maximum bulk metal production with minimum fog formation. The theoretical framework of simultaneous heat and mass transfer involved in condensation from gas mixtures containing a non-condensable gas has been extended to the high temperature and reduced pressure conditions. These apply to new technology for polymetallic smelting now being developed in a project currently funded jointly by the Commission of the European Communities and the Mineral Industry Research Organisation. Under the right conditions it is theoretically possible to condense out both lead and zinc with minimal fume formation, but in all practical cases it is anticipated that some circulating load for reversion back to the smelter will be needed.

Jan 1, 1989

Silver and gold bearing ore from the Palmarejo mine, located within the Mexican state of Chihuahua, contains a complex mix of electrum, native silver, silver sulfides and silver chlorides. This paper presents a case study that describes the selection, development and engineering of a tailored process plant for the recovery of silver and gold from this ore. Process circuit feasibility study modelling, metallurgical test work and engineering studies are outlined. Options considered to optimise the recovery of the contained silver and gold are compared, based upon cost, operability, recovery and engineering aspects. Concentration by flotation was found to be the preferred primary recovery route. Intensive leaching of the flotation concentrate resulted in solution grades sufficient to allow direct electrowinning to be evaluated against the more traditional Merrill Crowe process. The flotation tailings stream is processed through a separate leaching stage as there is sufficient economic metal extractable from this stream. The processing flow sheet, which is designed to maximise the recovery from both the flotation concentrate and tailings, and to utilise a common metal production facility, is presented.

Jan 1, 2009

Process Simulation and Plant Design of a Mineral Selective Magnetising Flash Roasting Plant Using Neutrons

Sep 13, 2010

Process Study on Some Ag-Cu-Pb-Zn Polymetallic Ore in South China

Sep 13, 2010

By Canterford JH

Current and future methods of data acquisition in hydrometallurgy are reviewed. Hydrometallurgical operations involve a wide range of chemical and physical processes for the recovery of metals and other products from ores and concentrates. Control of such operations requires information on the different liquid/solid and liquid/liquid mixtures being processed. Continuous. data acqui-sition for the liquid phases uses procedures already commercially exploited in other types of chemical plant. The major problem is the lack of robustness of measuring probes. Continuous analysis of the solid phases is much more difficult to-achieve because of the sampling and analytical techniques involved.

Jan 1, 1985

The Engineering Chemistry Division of the Government Chemical Laboratories of WA initiated an ongoing investigation into the possible utilisation of diatomites of this State. The work has shown that local diatomites can be beneficiated by hydro or pneumatic cyc- lone separator circuitry and that the better quality head materials can be upgraded by straight and flux calcination and associated processing to the equivalent of premium grade imported products. Western Australian diatomites vary con- siderably in quality, and the degree to which they can be upgraded and the yield of useful product are influenced by the proportion of impurities and the size, type, and degree of fragmentation of contained diatoms. Conseq- uently careful assessment of ore deposits will be necessary in order to relate ore reserves to planned production. The viability of commercial production from Western Australian resources would hinge on the establishment of markets - largely ex- port - capable of supporting a production level of the order of 30,000 tonnes per annum.

Jan 1, 1979

By R Shaw

There are many small to medium carbonate hosted complex zinc containing deposits where the zinc is not economically recoverable either as concentrate or metal. High grade (&gt;20% Zn) run of mine ore can be processed but even this material gives relatively poor returns. Considerable effort has gone into developing new technology for either upgrading the ore and/or recovering zinc metal hydrometallurgically but there has been limited success. Minetometal has developed a process capable of economically treating these deposits to give marketable lead and zinc products. This paper reviews alternative processes for these ores and gives a detailed description of the Minetometal Process. CITATION: Shaw, R, 2018. Processing carbonate hosted zinc-lead ores, in Proceedings Complex Orebodies Conference 2018, pp 130–131 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Kanau JL, Kilgour I

This paper describes the metallurgical processes at the 80 000tpd Ok Tedi Mining Limited concentrator, which treats copper- gold ore by single-stage crushing, SAG and ball milling and flotation to produce over 500 000tpa of concentrate. Plant and process developments, including installation of column cells, reduction of fluorine in concentrate, use of sulphidisation and process control improve- ments are also discussed.

Jan 1, 1991