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By Markus A. Reuter

In this paper various hybrid modelling architectures are proposed for the modelling and metallurgical control of pyrometallurgical reactors. Discussed are architectures in which data reconciliation is combined by thermochemical, neural net and dynamic modelling to improve the models. At the same time the data reconciliation models can act as soft-sensors for estimating unmeasurable data. Cases that are discussed are (i) the modelling of a submerged arc furnace for the production of thermal phosphorous, (ii) the processing of Sn-Pb-Zn flue dust (originating from secondary copper) in a hearth furnace, (iii) modelling of a steel converter, and (iv) dynamic modelling of a flash smelter.

Jan 1, 2001

By J. Kenneth Wittle

The DC Graphite Melter has been shown to be capable of processing radioactive waste materials. The process is characterized by its high temperature capability and operation in a closed system. From an environmental perspective, the control of emissions coupled with destruction for hazardous organic materials is mandatory. These same characteristics may be applicable to the minerals processing industry. Under normal operation, the system reaches temperatures for nominal operation of 1600°C, with an arc temperature in the order of 5000°C. The system temperature is determined by the melt temperature of the material being processed. In testing of a 750 lb/hour unit, temperatures of 2200°C were reached. Current focus is on finding waste treatment and metals recovery opportunities in the metals processing industry for his innovative technology.

Jan 1, 1999

The low grade Mount Charlotte orebody was first mined with minimum capital expenditure by mechanised cut and fill stoping. The lower block was prepared simultaneously for open stoping by shaft sinking and installing another crusher and services. Similar development for the third block was discouraged by economic factors and reduced tonnage. Decline develop- ment required less capital and opened up ore reserves commensurate with advance, providing flexibility to stop operations without commit- ment: A 1 in 7 decline measuring 4.25m x 5.5m to accommodate standard Euclid 25 tonne dump trucks was developed south of the orebody. A fleet of four trucks average 12 loads each per shift over a haul distance of 700m.

Jan 1, 1973

By M. H. Moys, M. M. Bwalya

"INTRODUCTIONThe grinding rate prediction scheme makes use of the energy spectra output from the DEM simulations and the statistical quantification of material strength, which can be done using the drop-weight tester or some other similar equipment. The prediction scheme is evaluated using milling experiments performed under well-defined conditions.MATERIAL STRENGTH QUANTIFICATIONUsing the drop weight test machine, particles of a wide size range were broken singly using different energy inputs. A characteristic equation key to milling rate prediction that relates the probability of fracture with energy input and number of impact attempts was obtained and is stated as follows:"

Jan 1, 2003

By M. H. Moys, M. M. Bwalya

The use of the Discrete Element Method (DEM) to simulate the interaction of particles in dynamic environments is growing rapidly. This technique is also being applied in the study of milling extensively. However, to date more focus has been on the validation of the model. In spite of the advantages of the detailed information that is available from the simulator, appropriate application of this information remains a daunting task. In this paper a technique that combines particle breakage probability data with the energy spectra generated from the DEM is discussed.

Jan 1, 2003

By T S. Fayram

The successful application of flotation is now over one hundred years old. However in a practical industrial sense, it still remains predominantly an art rather than a quantifiable science. Moreover, the laboratory testing, interpretation and application of the technology can still be tedious, time consuming and costly. This paper outlines the use of proven statistical design of experimentation software for rapid optimisation of flotation testing with limited representative sample utilisation. This results in less costly required testing, a more thorough understanding of results and the ability to simultaneously optimise several variables and outcomes at once. At the Center for Advanced Mineral and Metallurgical Processing, this testing methodology has been used successfully in many metallurgical development and plant optimisation projects thereby confirming its real world utility and application.

Jan 1, 2005

By Corby G. Anderson

"Laboratory testing, plant optimization, and the interpretation and application of metallurgical technologies can be tedious, time consuming and costly. This paper outlines the use of proven statistical design of experimentation software for rapid laboratory testing and optimization of operating plants with limited representative sample utilization. This results in less costly required testing, a more thorough understanding of results and the ability to simultaneously optimize several variables and outcomes at once. At the Center for Advanced Mineral and Metallurgical Processing (CAMP), this testing methodology has been used successfully in many metallurgical development and plant optimization projects thereby confirming its real world utility and application. Accordingly, several applied examples in flotation and hydrometallurgy will be outlined in this paper. This will include flotation testing of a copper gold ore, flotation testing of a copper, cobalt and gold ore, optimization of an industrial hydrometallurgical jarosite circuit and optimization of industrial nitrogen species catalyzed pressure leaching of a copper enargite concentrate.INTRODUCTIONWhile flotation technology is now 100 years old, the testing, interpretation and application of lab results can be tedious, costly and time consuming requiring extensive sample collection and preparation. In addition, recent applications like hydrometallurgical pressure leaching and associated unit operations, such as precipitation, still remain more of an art than a quantifiable science. This paper will elucidate the application of STAT-EASE Design-Expert software to minimize required laboratory testing while rapidly optimizing multiple results and outcomes in a statistically valid manner. The STAT-EASE program is based on proven design of experiment fundamentals. In this paper, the real world application of this methodology for lab testing, plant optimization and process development will be elucidated."

Jan 1, 2006

By Alfred E. Pugsley

PAYMASTER CONSOLIDATED MINES, LIMITED, began an investigation into the economy and use of detachable bit drill-steel in June, 1937. This investigation has continued to the present time, and was made necessary by transportation and distribution difficulties that had arisen through the use of standard steel in three widely separated mine areas serviced by a central steel-sharpening shop. Detachable bit drill-steel performance was first studied in the workings of No. 2 mine, where the rock being drilled was composed mainly of porphyry or tourmaline, and where standard drill-steel transportation costs had been excessive. The results obtained in this early work definitely established the economy of detachable bit drill-steel at No. 2 mine. This conclusion was reached when the 're-grind' system of re-sharpening dulled detachable bits was 1n use. Preliminary observations on the performance of detachable bit drill-steel in the quartz-carbonate veins of No. S and No. 6 mines gave encouraging results, and warranted a large-scale investigation under practical mining conditions. All drilling operations were gradually changed over to use of detachable bit drill-steel. This change was completed by February, 1938.

Jan 1, 1939

By V. Svalbonas

In the establishment of a useful failure criteria for complicated, fabricated structures, two basic areas of knowledge must be evaluated: 1. The accuracy of the applied stress analysis must be known in comparison with actual stresses encountered during mill operation. 2. The metallurgical fracture properties of the basic materials must be established with reference to non-destructive examination (NDE) methods to be used during fabrication. Both of the above can only be evaluated by use of full scale tests on the structures, and/or components, of interest. This paper describes such tests and comparisons as applied to several large mill installations. In addition, weldment component fatigue tests arid flawed casting strain gauge tests are also discussed. The combination of such test results allows for the formulation of failure criteria directly applicable to the fabrication and examination procedures followed in grinding mill structure manufacture.

Jan 1, 1982

By Donald H. Matthews

The usual method of dismantling massive concrete formations with explosives, is to totally demolish the entire concrete structure. If any portion of a concrete structure is required to remain in its original form and retain its structural integrity, the use of explosives is usually forbidden and the portion to be dismantled is demolished by mechanical means, using various techniques and equipment that are tedious and expensive.

Jan 1, 1978

By H. J. Ilgner

Previous applications for using waste rock for backfilling in South African gold mines were reviewed and it was found that in many cases the mechanical equipment selected and the design philosophy applied did not meet the requirements. A more simplified system configuration is proposed, which allows the equipment to be relocated as mining progresses. Innovative high-intensity grinding and dense-phase pumping technology are proposed to provide a low-porosity backfill with a particle top size of 5 mm to 8 mm. According to recent rock mechanics modeling work, this comminuted waste backfill material can provide a good compromise between underground support characteristics and reliable hydraulic transportation behavior.

Jan 1, 2001

By Kymberley Worrell

The Cripple Creek and Victor Gold Mine was acquired by Newmont in August 2015. The high grade flotation mill project was commissioned in February 2014. The mill to date has been throughput limited due to mechanical and design issues. In order to create the most value from a throughput limited plant a campaign to provide timely ore characterization was undertaken. A diagnostic leach methodology was developed to determine gold associations by ore type. The resulting associations were then used to characterize feed blend; gold losses and optimize gold production. The diagnostic methodology is presented along with discussion on flotation implications.

"A simple approach to optimizing the performance of an operating carbon in pulp (CIP) or carbon in leach (CIL) plant is presented. It is possible to reproduce the performance of an operating CIP or CIL plant in the laboratory, in small scale batch tests in which the rates of gold leaching and carbon adsorption are determined, coupled with mathematical models that translate the batch kinetic data into predicted steady state profiles of gold in solution and on the carbon across multi-stage adsorption circuits.Once the performance of the commercial plant has been mimicked by the model, the plant operating parameters can be varied systematically in the model, and the likely response of the plant to the stepwise change can be determined. In this way it is possible to inexpensively optimize the design of both greenfields CIP or CIL circuits and plant expansions, or optimize the operating parameters of an existing plant, with no disruption to plant operations and no economic risk to the mining company.This approach has been adopted by IAMGOLD Corporation, to the immediate benefit of two of their existing gold operations. The methodology adopted and the results achieved are presented.INTRODUCTIONThe carbon in pulp (CIP) and carbon in leach (CIL) processes became firmly established in the gold mining industry in the 1980s, initially in South Africa and Australia, from where they spread rapidly to all the gold producing regions of the world. The percentage of annual global gold production by activated carbon-based processes grew from zero in the 1970s to almost 70% by the turn of the century, which represented a phenomenal rate of acceptance of a new technology by a traditionally conservative industry. The main reason for this rapid acceptance of the new technology was the fact that the first few large plants built in South Africa convincingly demonstrated better gold recoveries than the traditional filtration/Merrill Crowe process, with lower capital and operating costs. And as the plants developed an operating track record over their first few years of life, they proved to be remarkably robust mechanically, and highly tolerant of plant upsets, changes in feed composition and solution phase contaminants that had caused problems in Merrill Crowe plants."

Jan 1, 2011

By S. S. Wang

Dialkyldithiophosphinates are a new class of flotation collectors for base metal sulfide ores. Structurally, they are quite different from the conventional collectors such as mercaptans, xanthates, thionocarbamates and dithiophosphates. Collectors Structures [Mercaptans R-SHS Xanthates R-OCS-M+ Thionocarbamates R-OCNH-R Dithiophosphates 2 R-CCNH-R' Dithiophosphinates (R) 2-PS-M+ ] In the above structural formula, R and R' stand for a hydrocarbon radical, and M+ is an alkali metal or ammonium cation.

Jan 1, 1982

By A. A. Lavrinenko, N. I. Gluhova, L. M. Sarkisova, D. V. Makarov

"The purpose of the study is to study the feasibility of using sodium diisobutyl dithiophosphinate (DDP) to enhance the recovery of platinum group elements from low-grade refractory copper-nickel ores characterized by a portion of nickel and platinum group elements (PGEs) locked in the dominant sulfide mineral — pyrrhotite. These ore characteristics dictate the need to produce a bulk PGE-containing sulfide concentrate due to the difficulties of producing selective concentrates without a significant loss of the metals.New data on the adsorption and flotation performance of DDP-containing collectors were obtained by measuring the electrode potential, hydrophobicity of the sulfide mineral surfaces and by means of extraction spectrophotometry and flotation studies. The interaction between DDP, pyrrhotite, and pentlandite leads to the formation of surface hydrophobic layers consisting mainly of disulfide and a small amount of metal compounds. These adsorption layers are formed by the reaction with butyl xanthate. In the case of cooperite, DDP reacts with the surface, forming not only disulfide, as in the case of butyl xanthate, but also a complex platinum compound. DDP-containing agents demonstrate stronger collecting properties with respect to sulfide minerals of copper-nickel ores compared to butyl xanthate, which is explained by a stronger hydrophobizing effect and foaming properties.The addition of a combination of DDP-containing agents and butyl xanthate at a ratio of 3:1 for the recovery of sulfides and PGEs in the bulk flotation of copper-nickel ore made it possible to improve the recovery of Ni, Pt, and Pd by 13.6, 9.2, and 9.4%, respectively, relative to the recovery achieved in flotation with butyl xanthate.Bulk flotation with the addition of a composition of DDP-containing agents and butyl xanthate allows the most complete recovery of all valuable elements and is the only technologically feasible method for processing of lowgrade ores, when it is impossible to produce without loss high-grade selective concentrates suitable for smelting."

Jan 1, 2018

By P J. Clark, A W. Fisher, R G. Ford

Site characterisation of subsurface contaminant transport is often hampered by a lack of knowledge of site heterogeneity and temporal variations in hydrogeochemistry. The use of a regional-scale data compilation derived from satellite imaging is discussed with respect to directing design of site characterisation to monitor the fate of a Dense Non-Aqueous Phase Liquid (DNAPL) plume in Nevada. Evaluation of the drainage basin contributing to the groundwater flux into the study site was used to re-assess the site conceptual model and re-direct the characterisation effort. The use of highly resolved measurements of subsurface hydrogeochemistry in space and time were employed to identify the predominant biogeochemical processes controlling arsenic transport during discharge of groundwater into a pond at a site in Massachusetts. Direct-push conductivity measurements coupled with vertically-resolved sampling within the pond and adjoining aquifer demonstrated spatial and temporal variations in dissolved arsenic within groundwater and the pond water column and sediment pore water. Spatial variability was observed over the scale of centimetres to metres, and temporal variations were observed over the scales of days (following storm events) to seasons. Microbially-driven redox processes maintained anoxic conditions in groundwater and at the sediment-water interface (iron and sulfate reduction) and exerted both a direct and indirect influence on arsenic solution speciation and partitioning to surface water sediments.

Jan 1, 2004

By William F. Ryan, Paul T. Gribbon

With the rise in construction claims in public works contracting over the years, the use of Dispute Review Boards (DRB’s) in underground construction contracts has become quite common. However, in order for the DRB process to be an effective tool, there must be complete trust and confidence in the Board members and their adopted procedures by both the owner and contractor. This can be difficult in an industry where Board members and contractors may be well known to each other, while an owner maybe involved in a large complex underground project only occasionally. Using case histories, this paper will discuss some recent experiences with the DRB process from an owner’s perspective.

Jan 1, 2003

It should be stating the æbleeding obviousÆ to say that the most efficient method of recovery must be used during the testing and evaluation phases of an orebody. Furthermore, the company will be literally throwing away money by not using the most efficient recovery plant during mining. This is especially true in the case of a low concentration/high value commodity such as diamonds. Unfortunately, this economic recovery criterion is not always the driving force. Some inexperienced companies think that they can preserve capital by using cheaper, and generally less efficient, recovery plants to mine their product. This philosophy is invariably a fallacy. Furthermore, it is also important to use the correct sized plant for the proposed task. It is no use trying to use a small testing plant to treat large quantities of ore, as this may result in loss of recovery efficiency. The converse is equally true.

Jan 1, 2004

By G Siboni, A Correa De Araujo, M Gotelip Barbosa, M J. Venturini

In support of the development of its Liberian iron ore project, ArcelorMittal Mining Research and Development (AM Mining R&D) has performed characterisation and beneficiation test work on drill core samples received from the proposed mine area. In addition to this, a sinter feed product was composed by blending and processing the drill cores in order to predict sintering performance of the ore. This article presents the methodology used to prepare the drill core blend for characterisation, as well as describe the sinter pot trial. The results are presented, demonstrating how important this type of study is for the development of an iron ore deposit.CITATION:Gotelip Barbosa, M, Siboni, G, Venturini, M J and Correa de Araujo, A, 2017. The use of drill core blends to predict sintering performance, in Proceedings Iron Ore 2017, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Martin C. Jones

INTRODUCTION This paper outlines the methods used to drill and pregrout prior to the excavation of five Mine Shafts in the Coal Measures of the Eastern United States. One example is the use of cement pregrouting of four 240 meter deep shafts and the second is the use of chemical pregrouting of a 360 meter deep shaft. These two examples will be compared and contrasted, both at the investigation stage of each project, and during the drilling and pregrouting itself, to illustrate the different approaches taken and how these affected the outcome, both technically and economically. INVESTIGATION FOR 240 METER SHAFTS In the case of the four 240 meter shafts, site investigation was carried out prior to bid, and information was made available by the Client in the form of a report. This report was based on pressure testing of NQ cored boreholes at each shaft site. Pressure testing was repeated two or more times, at each test setting, using 345 or 690 kPa of water pressure in accordance with the procedure outlined by the U. S. Bureau of Reclamation. Flow readings were taken every minute over a period of ten minutes. Maximum computed permeabilities, for the strata which accepted water under test for the shafts, carried between 1.0 x 10-6 m/s and 3.0 x 10-6 m/s, and total calculated seepages varied between 170' litres/minute to 3891 litres/minute. Although these figures did not indicate an excessive amount of seepage, the Client decided that pregrouting should be carried out, and chemical grouting was not discussed, even though the test permeabilities indicated the use of cement grout would be limited in this case.

Jan 1, 1979