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By L. Nell

Bateman, like other engineering contractors, carries out or participates in many studies of potential projects in the Minerals Industry. This paper aims to explain the contracting approach to feasibility studies as practiced by Bateman, particularly where this differs from a traditional mining company approach. A brief description is provided of the usual phases of a project and the types of estimate needed to proceed from one phase to the next. Possible organizational structures involving different forms of association between owner, contractor and consultants are then outlined. The bulk of the paper then demonstrates that the cost estimates prepared stem directly from the mining plan, metallurgical process design and engineering design philosophy. The steps to be followed in order to prepare a credible estimate which accurately reflects the design constraints are described. The importance and the methodology of carrying out value engineering and of preparing contingency estimates based on a thorough risk analysis exercise are then discussed. Financial modelling techniques are described briefly. The paper concludes with short summary case studies of two recent investigations of potential projects in Africa.

Jan 1, 1999

By R. M. Franz

This paper considers potential risks to the health of workers in ultra-deep mines, including barotrauma, physiological effects and toxicity of airborne pollutants. Relevant previous research is reviewed, including work by the Chamber of Mines Research Organization and the Deep Mine Cooperative Research Programme, and recommendations are offered for prospectively limiting pressure-related health risks.

Jan 1, 2005

By S. Kahraman

The correlations between the modulus ratio and penetration rate of rotary and percussive drills were statistically investigated using the raw data obtained from the experimental works of different researchers. An inverse power law was found between the modulus ratio and the penetration rate of rotary and diamond drills. The penetration rate of rotary drills and diamond drills decrease with an increasing modulus ratio. The penetration rates of percussive drills increase with an increasing modulus ratio. There are significant linear correlations between the penetration rates of percussive drills and the modulus ratio. In one of the cases of percussive drilling, a strong correlation between the penetration rate and the modulus ratio was found for the rocks having a porosity value lower 1.23 %. It can be concluded that the modulus ratio might be a representative measure of rock drilling efficiency. However, further study is necessary to check the validity of the derived equations for other rock types. The effect of porosity on the correlations between the modulus ratio and penetration rate needs to be further investigated.

Jan 1, 2003

By R. Scott

This article describes and evaluates the establishment of Kuyasa Mining including the search for a suitable deposit, the ongoing lack of finance, and market constraints. Despite the dramatic initial growth and success of their Ikhwezi Colliery near Delmas, Mpumalanga, Kuyasa?s experiences offer some sobering arguments for significant changes to mineral rights ownership, the attitude of financial institutions and government policy if South Africa is to have a dynamic and successful junior and small-scale mining sector.

Jan 1, 1998

By J. M. Schaekers

In the first part of the article, the authors give a broad overview of the chemistry and some engineering aspects of bioleach processes, eventually leading to the important and critical issue of the stability of arsenic-containing residues, especially those derived from bioleaching of sulphidic gold ores. In the section ?Factors affecting arsenic stability? they give an excellent summary of the factors normally affecting the stability of such residues. This is followed by some valid comments on the suitability of a single leach test to evaluate the long-term stability of solid waste streams. However, they fail to mention that, up till now, no tests procedure has been accepted by either environmentalists or the mining/processing industry as a valid method to test the long-term stability of solid wastes. Their own method is no exception, although, like many others, it is useful to identify potential problems with solid wastes considered for disposal.

Jan 1, 2001

By Willem C. A. van Niekerk, David A. Baldwin, Nardus Potgieter, Willie A. Gericke

Authorities that regulate environmental issues pertaining to industrial wastes in South Africa regard landfill disposal as the only effective environmental management option for slag and other inorganic by-products from the ferro-alloy industry. Metallurgical slags are widely utilised in civil engineering and construction applications in other countries in the world and in line with the overall philosophy of conserving mineral and other natural resources, these materials should be assessed for the possibility of resource recovery, recycling, reclamation, direct re-use or alternative uses. This presentation describes a risk-based approach for the assessment of by-products from the ferro-alloy industry for alternative use. Once a by-product from an industrial process has been identified for alternative use, its intended use would be defined, but it will not be possible to control its actual use or misuse in society, nor will it be possible to control its fate during the application life cycle. In the interest of protection of human health and the environment, potential risks associated with the handling and uses of a material throughout its life cycle therefore have to be quantified. The assessment has to include both human health and ecological risks and must cover the entire life cycle of a product, from its production up to its end-of-life disposal. The presentation introduces the concept of tiered risk assessment and demonstrates how this applies in the overall assessment of by-products from metallurgical industry sector for safe use in society.

Jan 1, 2007

By R. Flatabø, K-E. Johansen, L. Hunsbedt, P. M. Cowx, J. A. Bustnes

Eramet and Tinfos are two producers of manganese alloys in Norway, which have worked hard for several decades to improve both the internal and external environment. Furnaces producing ferro- and silico- manganese alloys generate large amounts of off-gas that contains substantial amounts of dust, heavy metals and organic by-products. The dust is separated from the gas in venturi scrubbers by washing with water. The water is cleaned and recirculated, and the surplus water coming from moisture in the raw materials, is discharged to the adjacent fjords after further treatment. Emission figures show that the discharge of suspended solids, manganese, zinc and PAH (polycyclic aromatic hydrocarbons) have been reduced substantially over the last three decades as a result of process improvements and installation of state of the art environmental control measures. The two plants were the first world wide to install mercury cleaning of the off-gases from the furnaces. Mercury emission reduction has exceeded 90%. Concerning other environmental issues, such as utilisation of off-gases for energy recovery and chemical purposes, both plants have achieved good results. Major effort in the environmental work has come from the plants themselves, but other players like FFF, The Norwegian Ferroalloy Producers Research Association, and SFT, The Norwegian Pollution Control Authority, have contributed to the achieved results.

Jan 1, 2007

By K. Sørli, H. Elstad, I. M. Skaar, A. Hildal

Generally, monitoring of refractory furnace linings is of interest to the metallurgical industry. The main issues are to control wear of the furnace lining and break out of molten metal. Penetration of molten metal through the lining can cause considerable damage to equipment in the vicinity of the furnace and endanger operators. Rebuilding of a furnace lining is expensive, mainly because it stops production, but also because the lining materials are expensive. Here, two methods for monitoring the lining of a smelting furnace are presented. The methods are based on monitoring of the temperature distribution in the lining, more specific monitoring an isotherm in the lining. One method is based on the assumption of unidirectional heat flow locally, reducing the problem to a set of one-dimensional heat conduction problems. The other method is based on inverse heat conduction. In this context inverse heat conduction means estimating the wear from temperature measurements using mathematical optimization techniques. The study is based on the ilmenite smelting furnace at Tinfos Titan & Iron KS. Some results from real temperature measurements and real observations from the ilmenite smelting furnaces is presented.

Jan 1, 2003

By Xu H.

In recent years, the mineral applications dealing with more complex data in distributed environment have grown rapidly. Many mineral and mining organizations have to organize internally and globally distributed manufacturing and experiment sites, which share the roles of databases and other multi-services like software programs. Thus, there are commercial and technical pressures pushing the mineral software vendors to move their current service toward Web service. XML has gained wide acceptance for representing, storing and transferring structured data and documents of many kinds, especially in scientific communities. However, so far there is no such a Markup Language in mineral industry. A XML-based uniform encoding, which is called MineML(Mineral Markup Language), is proposed and developed in this project. The framework of the MineML specification is created. MineML will play the role as shared protocols within mineral domain for archiving, transferring the multi-nature data between the software packages on the desktop over the Internet and sharing the services between users at different sites. Inspired by MLA’s (Mineral Liberation Analyser, JKMRC, University of Queensland, Australia) Mineralogical Data Presentation Program, a proof-of-concept prototype of Web Service is developed here to validate and demonstrate the MineML specification. Certain strategies, specific technologies and tools are adopted to create such an environment. To accomplish that, a set of experimental MineML documents including correlated XML, XSD (schemas) and XSL(stylesheets) documents have been elaborated for archiving, presenting and transferring the mineralogical data information, with the persistence on flexibility and extensibility for generic mineral and mining data handling.

Jan 1, 2003

By T. Phiri, Antoine Floribert Mulaba-Bafubiandi

Microwave energy has been recently used in minerals processing to speed up the leaching process or to improve the liberation of targeted minerals (Al-Harahshed and Kingman, (2003); Bradshaw et al., (2001)). Applied to the roasting of sulphide minerals, microwaves allow the ?tunning? of calcine types and products quality in addition to the energy savings as opposed to the conventional roasting (Mulaba, 2006). As more than 85% of world zinc is produced through the ?roast-leach-electrowin? route, an attempt was made to optimize cost, energy and product quality for metal extraction process route. The use of microwaves was the alternative process route selected for the optimisation. Pyrite concentrate (0.17% Zn, 0.09% Cu, 35.71% Fe, 43.76% S) and sphalerite concentrate containing 43.81% Zn, 0.37% Cu, 3.86% Fe and 44.39% S were microwave roasted in a multimode cavity of 2.45 GHz with varying power levels and for different durations. The produced calcines were characterized using AAS, XRF, XRD and Mossbauer spectroscopy while the determination of residual Sulphur was used as products quality control tool to ascertain the degree of roasting achieved on the feed. The leachability of the produced calcines in HCl, HNO3, H2SO4 and HNO3 + HCl has been studied in terms of the best leaching yield, process kinetics economics and environmental aspect. With 800 W power for 30 minutes, ZnO and Fe2O3 were formed corresponding to a 70% sulfur removed from sphalerite and 80% from pyrite concentrates respectively. While the roasting of the above concentrates appeared to be a first degree processes, it was noticed that the microwave assisted roasting of sphalerite and pyrite concentrates yielded lower sample surface temperature for a shorter time (i.e.less than 30 minutes) microwave exposition. Longer time (more than 30 minutes) microwave exposure showed a linear increase in temperature in function of power level used. While optimum roasting conditions were found at 800W, 30 minutes, a 10% increase of sulfur removal was noticed while pyrite concentrate was microwave roasted. Sulfuric acid was seen to give higher leaching yield than nitric acid. Zinc dissolution was hindered by the presence of franklinite.

Jan 1, 2007

By B. Derin, T. Uzunoglu, O. Yücel

In this study, reduction behaviours of Turkish chromite concentrate (48 % Cr2O3, 13.30 % FeO, 18.33 % MgO, 12.37 % Al2O3, 5.76 % SiO2) and nickel oxide by Fe-C alloy in graphite crucible were investigated. In the first stage of experiments, steel scraps were melted in graphite crucibles and were saturated with carbon at 1600 °C and 30 min. In the second stage, mixtures of different amount of chromite concentrate, nickel oxide and flux additives (CaO,SiO2 and CaF2) were charged into the graphite crucible containing the Fe-C alloy and heated to 1600 °C for different reduction times (0-180 min) under argon gas. The highest Cr and Ni con-tents in alloys were found as 11.41 and 14.37 % and the highest Cr and Ni recoveries were found as 88 and94 %, respectively at 180 min.

Jan 1, 2007

By Onuralp Yücel, Süheyla Aydin, Erçin Ersundu

Turkish iron and steel sector, the base of which was established in the 1930?s, plays an important role in the industrialization and development of the country?s economy. In Türkiye this sector is the major consumer of ferroalloys. There had been a great improvement in Turkish Iron and Steel industry, especially after the 1980?sand as a result, 20.9 million tons of yearly crude steel production placed Türkiye 11th in the global steel output and 3rd in Europe. 15 % of steel produced in Türkiye is flat products, while the long products make the rest. The product composition and the general characteristics of steel production process led to an increase in ferroalloy consumption. Domestically consumed ferroalloys are especially ferromanganese, silicomanganese, and ferrosilicon. As of today, ferroalloy production capacity of Türkiye is 173,800 tons/year; 161,500 tons of which is ferrochrome with high and low carbon grades, 7,300 tons of ferrosilicochrome and the rest is ferrosilicon (5,000 tons/year). Türkiye is one of leading ferrochrome producers in the world considering the above mentioned production figures. However, this production is mainly exported since Türkiye?s stainless steel production level is modest requiring low amounts of ferrochrome. The products of iron and steel industry in Türkiye require large quantities of other ferroalloys, which make Türkiye a major importer and exporter of ferroalloys. The aim of this work is to present production, consumption, import and export quantities of: ferrochrome, ferromanganese, ferrosilicon, ferromolybdenum, ferrotungsten, ferrotitanium and ferrovanadium of Türkiye, between 1990 and 2006.

Jan 1, 2007

The distribution of chrome spinels in a magnetically fractionated ilmenite concentrate sourced from the Murray Basin was characterized by XRF assaying, quantitative electron microprobeanalysis, grain mapping, automated mineral phase clustering, and modal analysis. At least 14 distinct chrome spinel types were present in the concentrate. There is considerable variation in the amount of each chrome spinel type present, although a high-Mg, high-Al phase makes up close to 45 per cent of the total spinel population. Magnetic fractionation results showed significant variation in the composition and relative abundance of spinels reporting to each fraction. Low magnetic field strength fractions (ie. high susceptibility grains) were dominated by chrome spinels that are mid-range in Al and Cr. These spinels have the highest magnetite, ulvospinel and Fe(Al,Cr)2O4components. In comparison, the high field strength fractions (i.e. low susceptibility grains) have the majority of the grains with high-Al contents indicating a higher proportion of Mg(Al,Cr)2O4component. Spinels high in a (Al,Cr)2.67O4non-stoichiometriccomponent are absent at low field strengths but tend to be concentrated in the high field strength, non-magnetic fractions. Intermediate field strength fractions tend to exhibit a broad spread in spinel compositional types. A mild roast treatment of the sample had no clear effect on the distribution of chrome spinels between different magnetic fractions, but it did cause a change in the magnetic properties of the accompanying ilmenite grains. The effect of more extreme roasting conditions on the magnetic properties of the chrome spinels is to be determined.

Jan 1, 2003

By M. Kumral

Raw material fed into a processing or refining plant is required to be uniform in composition for several reasons. When the mined ore is highly variable in quality the only way to ensure consistency is to homogenize the ore prior to the process. The problem is more complicated in the case of multiple ore sources. The idea behind the research is that theoretical blending ratios can serve not only to meet predefined specific criteria but also to reduce grade fluctuations of variables under consideration. In this paper, the problem is formulated as a quadratic programming problem, whose objective function is in quadratic form and constraints are linear. A case study was conducted on a data set from an iron orebody to demonstrate the technique. The objective was to minimize the blend variability in terms of each variable (in this study, iron, silica, alumina and lime) grade of ores extracted in three different production faces. The stockpile capacity, lower and upper limits of each variable satisfying operational requirements and non-negativity were constrained to the model. A modified simplex method developed by Wolfe was used for solving the blending and homogenization problem. The promising results can be used as apart of the stacking and reclaiming design. Keywords: blending and homogenization problem, quadratic programming, Wolfe method.

Jan 1, 2005

By A. Feather

Avmin have developed a flowsheet for the refining of copper, nickel and cobalt from Nkomati concentrates. Cobalt is recovered from calcium-saturated solution using Cyanex® 272. Nickel is subsequently extracted using versatic acid. The loaded organic is stripped using spent electrolyte, producing advance electrolyte for recovery of nickel by electrowinning. Cobalt was recovered with >99.5% extraction efficiency, reducing cobalt from 1.8 g/l to <10 mg/l. The cobalt/nickel ratio in the cobalt product solution was >1500. Nickel solvent extraction was optimized to recover 99%, reducing the nickel concentration from 32 g/l to <0.3 g/l, while minimizing calcium deportment to the nickel electrowinning circuit.

Jan 1, 2002

By Swapan Ghosh, Amitava Sengupta, Proloy Das

Ferro-alloys are very important ingredients used for making of quality steel with desired composition. In view of high demand in various types of ferro-alloys, it has become necessary to produce the same efficiently, safely and cost-effectively with consistent quality maintaining the anti-pollution norms. To achieve this goal, it is necessary to adopt latest process/equipment with the state-of-the-art instrumentation and automation system. A Programmable Logic Controller (PLC) based automation system with suitable Human Machine Interface(HMI) terminals along with intelligent field mounted sensing/control devices allows to monitor and control the complete plant effectively with optimum deployment of man-power. In association with this, use of process optimization controllers enables to achieve specialised functionalities of the submerged arc furnaces like material management, lining management, electrode management, power management, overall production management etc.

Jan 1, 2007

By F. Ntengwe

The Konkola Mine, a subsidiary of the Konkola Copper Mines Plc (KCM) which is owned by the Vedanta group of companies of India and Zambia Consolidated Copper Mines Holding limited, is located at Chililabombwe in the northern extension of Zambia&apos;s Copperbelt province. In its operations, the mine has been experiencing problems in ascertaining the optimum degree of fineness and the operating density of the hydrocyclone overflow in order to achieve high flotation performance. It was believed that recovery of sulphide copper minerals from Konkola ore is a function of the fineness of the grind so that it might be an economical justification to modify the grinding plant in order to run at lower cyclone overflow densities than the case is now. In an effort to improve these operations, it was decided to carry out test work on various hydrocyclones of sizes 0.381 m, 0.4575 m and on 0.508 m. The later was found to give satisfactory results and was installed on the plant. Despite giving satisfactory results there was need to investigate further to establish the working densities and size. Increasing the density of cyclone overflow decreases the per cent passing 75 pm at least in the range 1080-1 150 g/l. Furthermore, hydrocyclones give better separation at low densities of feed and hence the efficiency is high at low feed densities. Circulating load increases with an increase in feed densities and an decrease in the grind. The flotation performance in both sulphide and oxide copper minerals rougher stages is enhanced with an increase in the degree of fineness of the grind, with an optimum being obtained at a density of 1 150 g/l and 81.4% passing 75 µm. Keywords Konkola mine, hydrocylone, optimum degree of fineness, sulphide copper minerals.

Jan 1, 2011

By O. Gunaydin

Performance measurements of large-diameter circular saws were conducted on eight different carbonate rocks in marble factories located in some areas of Turkey. Rock samples were collected from these factories for laboratory tests. Uniaxial compressive strength, tensile strength and impact strength were determined in the laboratory. The brittleness of B3 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), the brittleness of B5 (the product of percentage fines in the impact strength test and compressive strength) and the brittleness of B8 (half of the product of compressive strength and tensile strength) were calculated from the test results. Hourly slab productions were correlated with brittleness indexes. It was concluded that sawability of carbonate rocks can best be predicted from the brittleness of B8.

Jan 1, 2004

By J. M. Font, R. G. Reddy

Jan 1, 2004

By R. M. Kear

Strategic and tactical planning are both required in the mining industry but have completely different objectives and require different environments. If these are not fully understood, then the best value for a mining operation may not be realized. This paper examines the differences in these approaches and how they interface in the mining environment. The objectives, content, skills required and the implied management issues for these two components are examined with the hope that this will assist management and the planning teams in defining their respective roles and expectations. The opinions are those of the author based on his experience on several mining operations and projects.

Jan 1, 2006