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By Sparrow G. J

In a recently completed AMIRA project, 20 samples were searched for gold mineralisation using the automated location facility (ALF) for rare phases on a scanning electron microscope in the CSIRO Division of Mineral Products, Melbourne. The samples were submitted by mining companies in Australia, and Papua New Guinea, and included crushed ore samples, cyclone overflow and underflow products, a flotation concentrate, and 12 tailing samples. Their gold contents ranged from 600 to 0.2 g/t An. Native gold and gold minerals including a gold telluride, gold-silver tellurides, and a gold bismuth mineral, were located in the samples as free grains and associated with other minerals such as pyrite, magnetite, hematite, ankerite, copper sulphides, silicate minerals, and quartz. In the highest grade samples, both micron sized and 200 ¦m grains of gold were found with ALF. It would be difficult to locate such d wide size range of gold in a manual search. Gold mineralisation was located in the tailing samples assaying 0.4 g/t An and higher. In several tailing samples coarse grains of native gold over 40 p.m in size were located. One grain was estimated to have contributed 40 per cent of the gold in the sample. As well as locating gold mineralisation, the ALF examination resulted in the identification of uranium, mercury, and bismuth minerals in the samples. Knowledge of the distribution of these minerals in processing streams could be important in the operation of a concentrator.

Jan 1, 1992

The use of black and white and colour infrared film in remote sensing of natural resources is reviewed. In heavlly-forested areas such as New Zealand, the main value of the method is in surveying the vegetation cover to detect the existence of plant communities characteristic of specific geological formations. By contrast in arid areas of Australia where the vegetation cover is sparse and where rocks and soils are well exposed, the method can be used in detecting different rock types or other geological differences.

Jan 1, 1972

By P. Venkatraman

Laboratory and pilot-scale test data have shown that the innovative feed presentation of the CrossFlow separator provides improved metallurgy when compared to traditional hindered-bed or teeter-bed classifiers. This design feature prevents excess water from entering the separation chamber and disrupting the overall fluidization flow rate within the teeter zone. Recent side-by-side industrial-scale evaluations have verified that this technology can improve overall efficiency, reduce the cut point of separation, and increase throughput capacity. This paper describes the important features that make this novel separator ideally suited for size classification and density concentration. Test data from heavy mineral, phosphate, and industrial mineral applications are also discussed.

Jan 1, 2005

By Antony: Guizado Aguedo Julio, Máximo Simon

La industria minera genera al día millones de toneladas de relaves al día producto de sus operaciones, las cuales son depositadas en presas de relave de grandes dimensiones. En consecuencia, la gestión eficiente de estos residuos para la mitigación de impactos en el ambiente, así como también la sostenibilidad de las operaciones se ha convertido en un gran reto de la minería actualmente. En ese sentido, mediante un enfoque de economía circular, el presente documento detalla la evaluación técnica realizada a los relaves auríferos de poderosa para su aprovechamiento como materiales de construcción prefabricados (ladrillos) mediante la generación de redes geopolimeras.

Sep 30, 2022

By P. A. Dimas

A new family of sulfide flotation collectors has been developed in our laboratory. These formulations are comprised of novel renewable materials combined with conventional reagents. The resulting diversity permits tunability of collector chemistry to meet a range of flotation problems. Several attributes of the new collectors are presented.

Jan 1, 2012

By Monica M. Jimenez Correa, Jorge A. Soares Tenorio, Denise Crocce Romano Espinosa, Paula Aliprandini

The surface zone of nickel laterite ore is generally considered as residue. However, because of the depletion of ore sources and the increase in demand, this previously discarded zone may now be processed economically for nickel and cobalt. After leaching and removal of the impurities, the solution contains cobalt, magnesium, manganese and nickel. Solvent extraction is a hydrometallurgical technique used in the separation of metals from aqueous solutions. Cyanex 272 and D2EHPA are extractants used to separate nickel from cobalt. The mixture of extractants can change the performance during the metals extraction. This work aims to evaluate the solvent extraction of nickel and cobalt when Cyanex 272 and D2EHPA are mixed. The results showed that the increased concentration of D2EHPA in the organic phase increased the extraction of nickel and magnesium. However, cobalt extraction was reduced and the manganese extraction was not altered.

Mar 1, 2018

By Wenxuan Xu, Shusen Cheng, Guolei Zhao

According to cross beam temperature measuring data of stock surface gas flow in blast furnace production process, using zoning method to deal with stock surface gas flow cross beam temperature measuring data, the evaluation system of stock surface gas flow distribution in radial direction and circumferential direction was established. Central index, platform index and edge index were proposed to evaluate stock surface gas flow distribution in radial direction, global uniform index and local uniform index were proposed to evaluate stock surface gas flow distribution in circumferential direction. Combined with actual production of 5500 m3 blast furnace and typical morphology of stock surface gas flow distribution,the strength of stock surface gas flow distribution was divided into five grades to provide guidance for the optimization of blast furnace operation.

Mar 1, 2017

By Bin Tang, Suping Yao

In the last decade, the copper industry in China has developed rapidly and attracted the world’s attention. The production capacity of refined copper has grown remarkably from 4.578 million tons in 2010 up to 9.029 million tons in 2018, accounting for about 40% of the global refined copper production. And now, China has become the biggest refined copper producer in the world. This paper summarizes the application of modern copper metallurgical technologies such as Outotec flash smelting/converting technology, Cyclone smelting technology, TSL (ISA/Ausmelt) smelting/converting technology, Jinfeng side blown smelting and Baiyin side blown smelting technology, Chifeng side blown smelting and continuous top blown converting technology, SKS bottom blowing technology, Dongying two-step smelting technology, copper electrorefining with high current density, etc. in China’s copper industry, analyzes and compares the characteristics of those technologies and presents the great efforts of China’s copper smelters in adapting to the increasingly strict emission standards and improving economic benefits of copper smelters. INTRODUCTION China has been the biggest refined copper producer in the world for many years. China produced million tons of refined copper in 2018, accounting for 40% of the copper smelting production in the world, and of which, roughly, 70% of the copper concentrate was imported, mainly from Chile, Peru and Australia. ICSG (International Copper Study Group, 2017) shows clearly the position of top 20 countries of copper production and copper mine production (Figures 1 and 2). Blast Furnaces, Reverb Furnaces and Electric Furnaces dominated China Copper Smelting for quite long time till 1980s. The first modern copper smelting technology (flash copper smelting) was introduced into China in 1980s, then followed by Noranda, Ausmelt and ISA. Since then, China copper smelting technology stepped into modern time. Since 2000, old processes (Blast Furnace, Reverb Furnaces and Electric Furnaces) were phased out and replaced by modern smelting technologies. China Copper Production has been increasing dramatically (Figure 3).

Jan 1, 2019

By Harold P. Rue

The problem of removing hydrogen sulphide from natural gas has become within the last few years one of major importance to the natural gas and petroleum industry. Several gas fields in the United States produce natural gas containing hydrogen sulphide, and a number of oil fields produce gas which contains hydrogen sulphide. 3 The percentage of hydrogen sulphide in natural gas produced in these fields varies from a fraction of 1 per cent to as high as 20.5 per cent by volume. Hydrogen sulphide is probably the most toxic gas associated with natural gas, and from the standpoint of health and safety it is important that the hydrogen sulphide be removed if the gas is to be used for domestic purposes. Hydrogen sulphide, besides being toxic and therefore a hazard to animal life, is under certain conditions an active corrosive agent and very destructive to equipment. The annual loss caused by the corrosive action of hydrogen sulphide on equipment amounts to hundreds of thousands, perhaps millions, of dollars. The largest percentage of natural gas produced in the United States comes from wells which also produce oil. This associated gas invariably carries with it light fractions of petroleum, which when separated from the gas, condense to the liquid form at ordinary temperatures and pressure. Commercial application is made of this natural condition, and "wet gas" is processed to obtain so-called natural gasoline by employing the principles of absorption, adsorption, or compression and subsequent expansion accompanied by cooling. In the manufacture of natural gasoline from wet gas which contains hydrogen sulphj.de, if this contaminating gas is not first removed, some of the hydrogen sulphide may oxidize to form free sulphur and water. The free sulphur will dissolve in the gasoline produced by any of the aforementioned methods and cause the product to be positive to the corrosion test and there-fore unsuitable for commercial use in that condition. The objectionable sulphur compounds can be removed by washing the gasoline with a solution of caustic soda or other chemicals, but this treatment is expensive. It is advantageous therefore to remove the hydrogen sulphide from the gas before it is processed in a natural-gasoline plant.

Jan 1, 1932

By Noel A. Warner

Modern steelmaking is based on direct use of oxygen in high intensity batch reactors. A totally new approach is proposed in this paper, based on the view that pursuit of high intensity is unlikely to lead to successful coal-based continuous steelmaking. By substituting carbon dioxide and water vapor as the oxidants rather than using oxygen directly, the intensity is greatly reduced. Accordingly, subsurface formation of carbon monoxide bubbles can be avoided by careful manipulation of the three participating rate processes, gaseous diffusion, interfacial chemical kinetics and liquid phase mass transfer. Steelmaking can then be carried out without explosive ejection of molten droplets and the generation of micro-spray but rather in a controlled and fume less fashion. The vital component is the introduction of generic melt circulation technology. Three melt circulation loops in series are envisaged. Starting with a composite feed of iron ore fines, pulverized coal and lime flux, a metallized solid raft floating on molten iron is propelled out of the ironmaking loop onto the first of two downstream steelmaking loops. In the first, a liquid slag is formed, primary decarburization is undertaken not with oxygen but rather with CO2 and H2O and the melt is desulfurized. The semi-product stream enters the third melt circulation loop, where open-channel decarburization is effected along with dephosphorization to yield a low carbon steel product. Alternatively, the melt leaves the last loop to irrigate a packed tower countercurrent to argon at around 100 mbar to continuously produce ultra-low carbon (ULC) steel.

Jan 1, 2003

By Kenneth R. Maser

This report describes the development of a system which modifies an existing fly ash-foam remote mine sealing technique to make it capable of impounding water in a fire zone. The modification involves blending equal quantities of fly ash and bentonite to form the bulk of the seal, and blending a thin layer of fly ash and Huron Regulated Set Portland Cement (RSPC) as a coating. The modification replaces the pure fly ash approach, but continues to use a froth foam topping to complete the seal. The modified material system is implemented with minimal complexity by adapting a "Y" connector to the existing delivery system. Each bulk hauler (fly ash and bentonite, or RSPC) will pump into one leg of the 'Y'; and the blending will be controlled by two pinch valves. The development effort has involved an evaluation of potential material systems by using small sample, quarter scale, and full head tests. The small sample tests measured the basic properties of a large number of selected material combinations. Property measurements included capillarity, permeability, shrinkage, and shear strength. As a result of these tests, particular combinations of fly ash-bentonite and fly ash-cement were selected for scale model testing in a 1 /4 scale test facility. These tests simulated, in a scaled manner, the water rise and total head which would be experienced by a seal. The tests indicated that shrinkage in the fly ash-cement combination would always result in leakage; whereas, fly ash-bentonite mixes were impervious to water.

Jan 1, 1974

By P. O. Akinseye, F. T. Cawood

Mineral royalties are one of the oldest forms of mining taxation, and were initially introduced to extract economic rents from mining. Over time, the royalty regime has become more complex as it was identified as an important policy instrument that can achieve more multi-faceted outcomes. Such a multi-tiered approach in the use of the royalty instrument is also the case with South Africa. With South Africa’s new mineral royalty regime now in place for ten years, it is perhaps time to assess its impact and effectiveness. To carry out this assessment, an econometric evaluative study was undertaken using four major commodities in South Africa, namely gold, platinum, iron ore, and coal. The study explored five different policy options for government to consider and tested them to determine the most favourable one that will realize the regime’s policy objectives. After the assessment, two major options stood out. Hence, this paper seeks to highlight which of the two options is the most favourable for consideration by policymakers. Based on that study, we find that the current structure is effective, but also recommend that the factors in the formula for refined minerals be ‘modified’ to reduce the capped profitability ratio from the current 60% to 30% and the maximum royalty rate for refined minerals from 5% to 3%. The minimum rate of 0.5% during times of depressed mineral prices and no or low profitability will not be affected.

Dec 1, 2021

By N. Ogbonna, D. G. Dixon

Although heap bioleaching has been recognized as an economic alternative for treating low grade mineral ores, the underlying physical, chemical and biological processes involved are complex. A detailed investigation into the dynamics of heap bioleaching processes has provided much insight into the underlying complexities, and has led to the development of a sophisticated modelling tool - HeapSim. This tool can be of great help in the design and operation of heap bioleaching processes. In this paper, the mathematical model implemented in HeapSim is examined. The model takes into account mineral kinetics, particle level effects, bacterial growth, oxidation and adsorption, gas absorption, pore diffusion, bulk advection, gas balance and heat conservation. Three case studies where the model has been applied are briefly discussed. Computational Analysis in Hydrometallurgy 35th Annual Hydrometallurgy Meeting held in conjunction with the 44th Annual Conference of Metallurgists of CIM Calgary, Alberta, Canada Edited by

Jan 1, 2005

By R. H. Hiltz

The Coal Mine Health and Safety Act of 1969 legislated maximum dust levels for the working place. As the law was implemented, extensive efforts were undertaken to provide the technology necessary to control dust generation. One approach to dust control was the use of high expansion foam in place of the usual water sprays on coal cutting equipment. At the time of the act, high expansion foam had already seen considerable testing for the suppression of dust in underground coal mines. Work by MSA, several coal companies and the Bureau of Mines itself had provided data which showed foam to have some merit as a dust control mechanism. It suffered in a few areas, however, which limited its practical application. Its principal difficulty was persistence which hampered operations due to foam buildup, but problems were also encountered due to equipment size and form.

Jan 1, 1975

By Jinxing Ji

Several fundamental aspects related to the nickel electrowinning from chloride electrolytes have been addressed in this paper. The thermodynamic study includes the activity coefficient of the hydrogen ion and the speciation diagram of NiCI2 solutions. The activity coefficient of the hydrogen ion (YH+) was calculated and estimated experimentally using a combination glass pH electrode. It was found that YH+ was greater than one in concentrated NiCl2 solutions and increased significantly with increasing NiCl2 concentration. The speciation diagram for NiCl2 solutions was plotted with YH+ and the effect of the ionic strength on the equilibrium constants being taken into account. It was discovered that the predominant nickel species in the acidic region were Ni2+ and NiCI+ in 0.937 M NiCl2 solution at 25°C. Electrodeposition tests demonstrated that higher Nit' concentration in the electrolyte improved the current efficiency of nickel electrodeposition (CENi). The additions of H3BO3, and NH4Cl increased very little the current efficiency of nickel electrodeposition at pH 1.5 and temperature 60°C. However, the addition of sulfate decreased the current efficiency of nickel electrodeposition. Nickel electrodeposition was also found to be a steady-state process since the amount of acid added to the electrolyte at a constant pH increased linearly with time during galvanostatic electrodeposition. The cathode surface pH during nickel electrodeposition was measured using a flat-bottom combination glass pH electrode and a 500-mesh gold gauze as cathode. The cathode surface pH was found always to be higher than the pH in the bulk electrolyte, and if the current density was sufficiently large, it would eventually reach a level causing precipitation of insoluble Ni(OH)2(s) on the cathode surface. Rotating disc electrode studies revealed that the rate of nickel electrodeposition was first order with respect to the activity of nickel ion and zero order with respect to the activities of chloride and hydrogen ions. The rate of hydrogen evolution was found to be first order with respect to the activity of hydrogen ion and to be zero order with respect to the activities of nickel and chloride ions. These findings indicate that nickel deposition and hydrogen evolution proceed independently.

Jan 1, 1995

By Juan Carlos Salas

In this paper, a collaborative R&D model which has been successfully applied by a global mining companies association is presented and analysed both from the conceptual and practical point of view and an example of these collaborative initiatives, the Copper Technology Roadmap recently generated by a group of the most relevant copper mining companies, is presented, including an analysis of strategic opportunities and challenges in the Latin American region.

Sep 9, 2007

By J. Quinteros-Riquelme

Despite increasing demand, the supply of silver is limited by its inadequate recovery from ores. Due to its scarcity in nature, its high ore variability and complex mineralogy of current silver deposits, its recovery by mineral froth flotation presents a real challenge for process engineers. A silver ore often contains significant amounts of five to ten different silver minerals and knowledge of the mineralogy is a necessary precursor to flotation testing. In this work, a complex silver ore was treated by using batch laboratory flotation, in an effort to find the best experimental conditions to obtain the optimal silver recovery. Mineralogical characterization of feed samples was conducted using a combination of tools, namely the mineral liberation analyzer (MLA) and inductively-coupled plasma mass spectrometry (LA-ICP-MS), which indicated that most of the silver occurred as ?invisible? silver in pyrite. The pyrite assay of the ore was approximately 4%. The ore was processed in two flotation stages. The first stage, sulphide flotation, aimed to collect a sulphide mineral rich concentrate; then a non-sulphide flotation stage was performed by adding sodium sulphide and collectors to the remaining material in the cell, with the objective of obtaining a pyrite rich concentrate. To reach the target recovery of silver from this ore, various variables were altered. In the first stage: mixed collectors, activators, dispersants, and mainstream inert grinding were assessed. In the second stage, the conditions for sulphidization and subsequent flotation were both investigated. From the grade recovery curves for silver and sulphur it was possible to observe a similar metallurgical behavior for both elements, supporting the results given by the mineralogical characterization. Keywords: silver oxide, froth flotation, sulphidization, mig

Sep 1, 2012

By Sang Bum Chi

In order to better predict and manage benthic disturbance by deep seabed manganese nodules mining, we needed to conduct a benthic disturbance experiment at the selected area, which has a similar environmental condition as the preservation reference area. Therefore, we have performed environmental baseline studies from 2003--not only to select the benthic environmental impact testing site but, also to detect any environmental changes before and after mining activity. Since then, a large dataset of various parameters ranging from physical (e.g. temperature, salinity, current, weather), chemical (e.g. dissolved oxygen, nutrients, dissolved and particulate organic carbon), biological (e.g. bacteria, plankton, benthos), geological (e.g. Mn-nodule abundance, sediment shear strength) and others (e.g. bathymetric profile and slope, mass flux) have been accumulated. Using this dataset, descriptive statistics and cross-correlations were performed to select the benthic environmental impact testing site. Outcome of this analysis suggests that the potential benthic impact testing site would be a rectangular-shape area (10 km × 10 km) and located at 10°27'~10°33'N, 131°53'~131°58'W, which is latitudinally the same as the preservation reference area.

Jan 1, 2011

By J. D. Pitts

The worldwide production of iron ores was approximately 880 million metric tons in 1975. This level is the result of an annual growth rate of nearly four percent during the period 1967 to the present. The high growth rate was particularly significant in that two relatively severe worldwide recessions occurred in 1971 and 1975. The current upturn in world economic growth will probably allow future annual iron ore production growth rates in excess of the four percent figure, and, in fact, the International Iron and Steel Institute (IISI) has predicted that a five percent rate should be realized through 1985. The IISI figures would indicate a 1.4 billion metric tons per year output by 1985 or an increase in current production levels of around 500 million metric tons per year (MMTA)1. Even the more conservative four percent growth rate prediction from historical data would provide an 2 increase over current figures of nearly 350 MA by 1985. A large portion of world iron ore production is being provided by large resource-rich countries with relatively new industrial bases. These countries are typified by heavy export of raw materials such as iron ore and ore products and a large capital investment in the facilities to recover these raw materials. Brazil and Australia are typical of such countries and, indeed, their production of iron ore in the period 1967 to 1973 increased at annual rates of 17 to 30 percent, respectively, The continual reassessment of resources in these and other major iron ore exporting countries such as Venezuela and Liberia would indicate chat these high growth rates may continue for some years to come to meet anticipated world demand for raw steel production.

Jan 1, 1976

By Hans E. Tausig

The economics of transporting minerals by sea in less than full cargo lots encompasses an analysis of production costs, sale and inventory calculations and a careful comparison of ocean freight costs all of which when pieced together will usually definitively indicate which of the ocean freight alternatives is the correct one for the economic factors involved. To illustrate: Let us assume that a production to be marketed yields 60,000 metric tons of copper concentrates over a twelve month period. Shipment is geographically viable through Vancouver, B.C. The production has been sold to a Japanese Smelter and the mine produces at a rate of 5,000 metric tons of concentrates per month. The copper has been sold CIF FO. The Seller has carefully investigated ocean freight rates Vancouver, B.C./Hibi, Japan and finds that he could obtain a twelve month freight contract at $15.00 per metric ton FIGS based on a loading/discharging speed of 4000/ 2000 metric tons per WWDSHEX (weather working day, Sundays and Holidays excluded) this freight rate being predicated on shipping in lots of minimum. 15,000 tons. A further freight investigation reveals that to ship at the same terms and conditions but in lots of 5,000 tons, and shipping each month (in accordance with the mine's actual production) would cost $20.00 per metric ton FIOS. The calculation that is now made is whether it is more desireable to pay a higher ocean freight by shipping in 5,000 ton lots or to pay the lower freight where here the ocean freight involves a difference of some $300,000.00.

Jan 1, 1979