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By D La Rosa, D Bennett

"Exploration drill core provides for a number of standard measurements essential for determining the viability of a new mine or the extension of an existing one. Rock lithology and alteration can be visually determined and grade measured from the half core. Geotechnical parameters such as rock strength and structure can also be measured. Using suitable proxies, these metrics can then be used to estimate run-of-mine (ROM) particle size. In combination with comminution test results, these can subsequently be used to design comminution circuit configurations and estimate their performance.The Frieda River Project drill core for the large Horse-Ivaal-Trukai copper-gold porphyry deposit was unusual due to a late stage gypsum-anhydrite stockwork event that overprinted much of the deposit. Above the base of the oxidised zone, which closely matches the water table, gypsum and anhydrite has been leached out, effectively removing the glue holding the rock mass together. As a result, much of the rock above this gypsum-anhydrite surface is fragmented and gravel-like in texture, while the material below this horizon is typically uniform and competent.Large volumes of the orebody above the gypsum-anhydrite surface are expected to need minimal or no blasting for efficient excavation. In addition, the fragmented nature of much of the material was expected to reduce comminution specific energy as it already appears as though it has been crushed. While this was expected to have positive impacts to the operation, the lack of standard geological logging methods available to accurately define the degree of in situ fragmentation led to difficulty in gaining certainty over the ROM product and grinding circuit feed size distributions.Using the extensive library of core photos for the project, a novel method using image analysis techniques to take both the intact core and gravel into account to predict ROM fragmentation was developed. In addition, existing point load test data was used to infer the strength of the rock and its impact on the blasting, crushing and grinding processes. The novel approach allowed development of ROM size distribution data and improved certainty in the results of comminution circuit designs.This paper describes the methodology undertaken in detail, and discusses the results obtained.CITATION:Bennett, D and La Rosa, D, 2016. The Frieda River Project – a Novel Approach to Analysing Exploration Drill Core: How Broken is Broken?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By R. E. Scheffel

Most supergene copper heap leach operations today employ forced-aeration, irrespective of ore grade. Unfortunately, there is little published quantification of its benefit. There is a natural desire to strive for the ideal chemical kinetics. The reality, however, is that physical mechanisms control the commercial extraction rate. This paper presents the performance of a number of operations, their operating conditions and physical ore characteristics, which contribute to non-ideal solution distribution and variable extraction rate. Regardless whether one uses forced-aeration, commercial experience to date suggests it is prudent to design for longer leach cycle times to ensure the production target is met.

Jan 1, 2006

By P. D. Chamberlin

Agglomeration for the heap leaching of gold and silver ores can be defined as the process of attaching fine ore particles (less than 100 mesh) to coarser particles so the fines are immobilized and uniformly distributed throughout the heap, thus making the heap more porous and uniformly permeable to the flow of a leaching solution. Agglomeration techniques and equipment to be described include drum and disc agglomerators, stockpile and belt agglomeration, and the use of vibrating deck and reverse running conveyors.

Jan 1, 1986

By Peter M. Solozhenkin

Considering the main idea of the paper, namely that the interaction energy of reagents serves as a criterion used for their selection, as well as due to their insufficient study, the authors have therefore considered studying the aspects of computer modelling and molecular dynamics of largely used collectors for the flotation of nonferrous and precious metal ores. Three-dimensional molecular models for sulphydric reagents have been created, studying as well the distribution of the partial charges on their atoms. It has been shown that the value of the partial charge on the phosphorus atom in diethyldithiophosphinate and diethylmonothiophosphinate is high positive. The value of the partial charge of the sulphur atom is negative, strengthening its bond with the metal cations from the mineral surface. The molecular orbitals for the sulphydric reagents have been created determining as well the energy of their level. The computer modelling key parameters have therefore been defined. The new reagents have been tested for gold, copper and rhenium ore flotation. Gold recovery has increased with 4.2 - 4.7 %, copper recovery with 3.3 % and rhenium recovery with 15.5 %. A number of new flotation reagents have been recommended, such as: diethyldithiophosphate, (C2H5)2NCH2CH2OC(S)SNa, (C4H9NH)2P (S)SNa and also (C2H5)2P(S)ONa and (C2H5)2 P(O)S Na. Keywords: flotation, molecular modeling, design, orbital?s

Sep 1, 2012

By Marco Sonnenschein

As time is costly, engineering companies have developed methods, procedures and mechanical equipment to tunnel faster. But the best excavation method will not be able to cope with the time pressure if there is not a reliable backup system. Therefore, the application of belt conveyors for tunnel boring machine (TBM) drives as well as for drill-and-blast driven tunnels assure a quick and smooth removal of excavated soil in order to enhance the efficiency of the tunneling equipment. During the last 10 years, belt conveyor systems have achieved ?state-of-the-art? levels and have become the first choice for muck removal systems in both TBM and drill-and-blast driven tunnels. Because time has become such a key criterion in tunneling projects, it is essential that all equipment is operated so as to derive optimum efficiency and minimize costs. Efficiency also means to think about new tasks for existing technologies.

Jan 1, 2012

By R. I. Jaffee, F. C. Holden, H. R. Ogden

The effects of ternary and quaternary additions of aluminum, oxygen, and carbon on the mechanical properties of high-purity titanium-molybdenum alloys were studied for several microstructural conditions. Heat treatments were designed to produce 1) ß-quenched, 2) equiaxed ß) transformed (acicular) and 4) stabilized -P microstructures. Tension, impact, and hardness tests were performed. Transformations from the ß phase were followed by hardness measurements and metallography. The ß-to-w transformation was slowed by aluminum additions; carbon and oxygen additions increased the transformation rate. In addition to solid-solution strengthening, these solutes may increase or decrease strength by altering the /3 transformation kinetics. Aluminum additions promote the formation of strain-induced martensite, and lower yield strengths at compositions near 12 pct molybdenum.. a-P alloys are more ductile with equiaxed than with transformed microstructures. High strength levels can be reached by aging in many cases. Strength levels of the aged specimens usually are lowered slightly by straining prior to aging. ALLOYS of molybdenum with titanium form an iso-morphous alloy system which has been the subject of several investigations. Additions of substitu-tional and interstitial -stabilizing elements provide means of improving mechanical strength and con- trolling the heat-treatment response of the binary alloys. The work reported here forms a part of a continued study of the effects of microstructure on the mechanical properties of high-purity titanium alloys. Previous papers have considered the various binary alloys (Ti-Mo, Ti-Al, Ti-C, and Ti-0) that form the bases for the ternary and quaternary alloys included here. The compositions were selected to correspond with the previous binary alloys. Further, the high purity of the alloying components was maintained, so that direct comparisons with earlier work can be made. The total research program included a large number of compositional, microstructural, and testing variables. The data reported here have been selected to provide a reasonably complete and representative summary of the results. The reader is referred to the original Air Force Report for a complete tabulation of the results. EXPERIMENTAL PROCEDURES All the alloys used in this work were prepared from high-purity electrolytic titanium produced by the U.S. Bureau of Mines. A typical furnished analysis showed the following impurities in wt pct, balance This analysis is equivalent to that of iodide-refined titanium. In addition, hardness, tensile, and impact tests made using unalloyed electrolytic titanium showed it to have properties equivalent to those obtained with iodide titanium and suitable for these studies of high-purity base alloys.

Jan 1, 1962

By J. Erik Loehr, Andrew Z. Boeckmann

"Poor drainage is a common cause of poor performance of earth retention systems, resulting in burdensome serviceability problems that can progress to outright failure of the retention system if not addressed. A drainage system consisting of filtered conical drains that can be installed through the face of an existing retaining wall and readily maintained was evaluated through tests of physical and numerical models. The physical models were constructed with different backfill materials in a container measuring 8 ft wide by 4 ft tall by 15 ft long. Tests were conducted by saturating the backfill under a constant water elevation atop the model, and then maintaining the water elevation until seepage from the drains reached a steady state condition. Pore pressures within the backfill and outflow from the drains were measured to facilitate calibration of numerical models that accompany the physical models. Results from the calibrated finite element models were used to develop design criteria for the drains. The design criteria establish the required drain spacing as a function of the height of groundwater above the drains and the diameter of the drain.INTRODUCTIONMany retaining wall performance problems are a result of poor drainage of the wall backfill. Consequences of poorly drained backfill include displacement and rotation of the wall face, including the extreme case of collapse, and seepage through the face of the wall, which is in turn associated with damage from corrosion, dry rot, and other forms of deterioration. A common approach to improve drainage of an existing wall is the installation of drainage features (e.g. “weep holes”) in the face of the retaining wall. Weep holes facilitate controlled seepage through the face, which relieves water pressure within the backfill and directs seepage to known locations in the wall face. Although installation of weep holes is relatively common, engineering methodologies for selecting the size (diameter) and spacing (along the wall) of facial drainage features are uncommon if not altogether non-existent. This paper documents tests of physical and numerical models of retaining walls with facial drainage features, including conventional weep holes as well as maintainable drains installed through the face and extending into the wall backfill. Results of the testing were used to develop generic design criteria, which establish the required drain spacing as a function of the height of groundwater above the drains and the diameter of the drain."

Jan 1, 2016

By H. Thalenhorst

For an advanced mineral exploration project that has a ?nugget? issue making the assessment of the deposit grade difficult, a bulk sampling program using a sample tower can provide information that is otherwise not obtainable prior to actual production. This information includes the verification of predicted resource grades for the bulk sample tonnage (and, indirectly, of the methods and parameters used for the grade estimate), confirmation of the physical and grade continuity of the mineralization, and geotechnical data for a future mining operation. The information gathered will improve the input of a feasibility study, particularly with respect to expected mining grades, which are the key economic parameter for most mining projects. The bulk sample rejects can be used for pilotscale metallurgical testwork. Bulk sampling is also useful in cases of potentially biased drill-hole assay results and in the reliable determination of ore grade before shipment of ore from production or development operations to an external beneficiation plant. This paper presents a practical bulk sampling and sample preparation protocol, lists design features for the sample tower, examines the sampling errors that will be encountered, provides information on quality control procedures, and looks at the costs and benefits of such a program, based on the experience of undertaking bulk sampling programs during the period of 1985 to 2008.

May 1, 2010

By G. Mousavian, R. Bagheri, N. Dalili

Polypropylene (PP) and its composites have an increasing use in automobile and domestic industries. Since the published results on strain rate effect on yield behavior do not match, and there is a high attention paid for effect of nanometeric fillers on deformation behavior of composites, in this research the strain rate effect on yield behavior of PP and the effect of nanometeric fillers on deformation behavior of PP have been studied. Microscopic observations and tensile tests in different strain rates on neat PP samples and on samples filled with 5, 10 and 15 %wt have been used. A dramatic change in behavior for the modulus and post-yield slope curves when the strain rate is between 0.0433-0.05 s-1 has been observed. Microscopic observations on PP indicate a change in deformation mechanism from shear yield to crazing at the same strain rate that the change in behavior of curves occurs. It has been observed that in PP nanocomposites with higher amount of calcium carbonate, fracture in early stages of deformation occurs in lower strain rates. In other words for a fixed stain rate there is a critical filler percentage such that if the filler percentage is higher then early-stage fracture will occur. Similarly for a fixed filler percentage there is a critical strain rate and in higher strain rates early fracture will occur. The critical stain rate will decrease as the filler percentage increases and vice versa.

Jan 1, 2006

By İbrahim Alp, Emine Yoğurtcuoğlu

This article includes the application of roasting pretreatment by assisting the cyanidation process in the recovery of Au–Ag from Bolkardağ Gossan refractory ore and the characterization studies of the ore, roasting sample, and postcyanidation waste sample. While ore contained many metals along with gold and silver, the environment in which these metals were found was carbonate, sulfated, silicated, and iron oxide-containing deposits that have undergone oxidation. In mineralogical studies, there were Fe oxy/oxyhydroxides, Pb/Zn carbonates, and jarosite-bearing structures such as beudantite, calcite, dolomite, clay, and quartz in the ore. The sample used in the experiments was d80 = 29.6 μm, and the test parameters were determined by examining the TG analysis made to the ore. Preroasting experiments were carried out at a roasting temperature range of 200–800 °C, during a roasting period of 10.0 min. Three different samples were characterized by TG for temperature changes, FT-IR for bond structures and permeability, SEM/EDX for visual inspection of structural changes, and XRD Rietveld’s analysis for mineral % content differences. As a result of the cyanidation experiments carried out after the pretreatment, gold was recovered with 80–90% yields and silver with 40–48% yields, respectively.

Aug 21, 2023

By P. W. J. van Rensburg

Our mineral heritage - PRESIDENTIAL ADDRESS given by P. W. J. van Rensburg, Pr. Eng.. B.Sc. (Eng.)(Rand) INTRODUCTION Stone Age people were living in various parts of South Africa as recent,ly as a thousand years ago, when they were displaced by Iron Age people with a culture developed in the far north. These invaders brought farming, building, and the earliest mining developments to the Transvaal, thus ushering in the beginning of our great mineral heritage. It is of particular interest to record that, up to comparatively recent times, some of these people were excavating iron-bearing shale rocks for their smelting furnaces on the Melville Koppies in J ohannesburg. Although the most recent the iron-smelting furnaces discovered on these koppies is estimated to be some five-hundred years old, it believed that these Iron Age people were driven out, and their settlements destroyed, by Zulu impis only one-hundred-and-fifty years ago.

Jan 10, 1973

By O. T. Konina, V. A. Masloboev, A. V. Svetlov, E. A. Krasavtseva, D. V. Makarov, A. A. Goryachev

Dusting phenomena have been examined at the tailings storage facility of Apatit JSC Kirovsk, a mining operation located in the far north of the Russian Federation. The material composition of the tailings was identified. Existing dust suppression methods were examined. Field observations were undertaken and official data was obtained from the Murmansk Administration for Hydrometeorology and Environmental Monitoring, and analysed. A database was built for forecasting dusting according to critical scenarios in order to estimate the peak MPCs of suspended solids in the atmospheric air. Mitigation measures were formulated and recommended to the mining operation. Keywords: Mineral dust particles, apatite-nepheline ore concentration tailings, suspended solids MPC, climate change

Jan 1, 2020

By Yingchang Tsenshan Wang

UUIN L&SS 1» Paqb I. Introduction........................................................658 1. Subject and Scope...............................................658 2. Acknowledgments...............................................659 3. Review of Previous Work........................................659 Field Data...................................................659 Experiment.a1 Data............................................662 4. Plan of Present Investigation.....................................662 Method of General Procedure...................................663 I1. Experimental Work..................................................663 A. The Solution of Sphalerite..............................:........663 1. The Solvent Effect of Iron Sulphates upon Sphalerite...........663 2. The Solubility of Sphalerite in Salt Solutions of Silver, Copper and Lead...............................................668 B. Formation of Zinc Carbonates....................................674 3. The Reactions of Carbonates and Bicarbonates With Solutions of Zinc Salts............................................674 4. The Reaction of Zinc.Sulphate Solution With Limestones.......684 C. Peculiar Conditions Affectitig the Formation of Zinc Silicate (calamine) and Zinc Carbonate (smithsonite)..........................686 5a. The Effect of Carbon Dioxide Upon the Basic Silicate and the Carbonates of Zinc in Water, and Its Bearing Upon the Conditions of Theii Precipitation..............................686 5b. The Reactions of Solutions of Soluble Silicate With calamine and Smithsonite in Solution in Presence of Carbon Dioxide..689 6. The Reactions of a Mixture of Hydroxide and Silicate of Sodium with a Dilute Solution of Zinc Sulphate...................691 D. High-Temperature Methods.....................................692 7a. The Influence of Temperature on the Formation of Calamine..692 7b. Possible Effect of Heat on Calamine and Srnithsonite.........697 E. Summary of the Experimental Work..............................698 III. Petrographic Work....................................................700 1. The Occurrence of Sphalerite in Limestones or in Cherts............701 Summary of the Blende in Limestones and in Cherts.............7432 2. The Partially Altered Sphalerite and the Oxidation Products........702 a. Smithsonite with Blende....................................702 b. Calamine with Blende......................................703 c. Smithsonite and Calamine..................................703 d. Summary on the Partially Altered Sphalerite and Its Oxidation Products..............................................704 IV. Concl~~siom ........................................................-705 V. Microphotographs and Photographs with Their Explanations.............705

Jan 1, 1916

By P. T. Brooks

Semipilot scale tests were made to demonstrate a newly developed electrorefining process which could be extrapolated to commercial scale in producing high-purity nickel and cobalt from crude nickel metal and high-grade ferronickel. The new process comprises application of solvent extraction techniques to remove and separate cobalt and iron from nickel and the electrodeposition in diaphragm cells of pure nickel and cobalt from chloride-based purified electrolyte. Using water insoluble organic amines, the solvent extraction operations enabled production of commercial-sized nickel and cobalt cathodes of higher purity than that of commercial electrolytic metals. The solvent extraction operation for separation of cobalt from nickel was made simpler than the conventional method. Furthermore, the solvent. extraction operation for iron removal made possible the electrorefining of ferronickel without the prohibitive loss of nickel resulting from the method ordinarily used for iron removal.

Jan 1, 1970

By David B. Crouch

Wastes in various forms have always been a part of mining, and management of mine waste has evolved from the early days of "push it over the side and down the creek" to today's highly engineered waste facilities. Changes have been brought about not only by technological advances in the ?3M?s? - mining, milling, and metallurgy - but also by environmental awareness and changing social values that have been manifested in an ever-growing maze of regulations. This is a dynamic era, and the debate goes on. So it is that planners have to anticipate permit and regulatory requirements in the site-selection process along with the traditional criteria. The McLaughlin gold project is an example of how one company, Homestake, has met this planning challenge. In August of 1980, Homestake Mining Company announced a major gold discovery in northern California known as the McLaughlin Project. The property is approximately 80 air miles northeast of San Francisco near the junction of Lake, Napa, and Yolo Counties. This is an area where mercury has been mined off and on for over 100 years; gold has never been mined in the area. The gold is microscopic and finely dispersed in a complex geologic setting. Reserves are estimated at approximately 20 million tons at a grade of approximately 0.16 ounces per ton.

Jan 1, 1983

By J. K. Brimacombe

"Nearly all the easy things have been investigated in injection metallurgy. Water models have been used exhaustively to study mixing, gas distribution and flow in submerged jets. Mathematical models have been developed with their restrictive boundary conditions to quantify submerged gas jet behavior. While being valuable tools to our understanding of injection metallurgy, there is an obliqueness to their application. What we need now are measurements and modelling on the actual systems, hot and unfriendly, where gas meets liquid at temperatures above l000°C. This is where the challenge lies.AN APPRECIATONThere are those who follow the trail and there are those few who blaze new trails in search of novel concepts and processes. With his restless, inventive mind, Howard Womer is a trail blazer without doubt. Decades ago, he was a pioneer in the pursuit of continuous steelmaking with the WORCRA Process and, today, he is developing new processes for the treatment of waste. He is not only an inventor but has been a professor at the University of Melbourne and was the first Director of Research at BHP. He has influenced the lives of many people, including myself; with his achievements and humanity. Therefore it is most fitting that this symposium should be held in honour of Howard Womer, a luminary in the metallurgical world for over half a century.BACKGROUNDGas injection has been an integral part of pyrometallurgical processes since the early days of Bessemer, then of Pierce and Smith. Today, of course, one cannot imagine pyrometallurgical processes without submerged gas injection to effect reactions for metal extraction and refining, to provide mixing and to inject solids into molten metal, slag or matte. Spurred on by new developments like tonnage oxygen and argon production, the Savard-Lee concentric tuyere and porous plugs, new steelmaking processes have emerged; and now solids injection is changing copper extraction processes. The ingenuity of the extractive metallurgists who drove these developments is inspiring for they have applied gas injection to transform pyrometallurgical processes. Humankind has been the beneficiary.' Today these processes are safer, more efficient, cost effective, less energy intensive and more environmentally friendly."

Jan 1, 1996

By U. S. Geological Survey

In 2025, the estimated total value of nonfuel mineral production in the United States was $112 billion compared with $106 billion in 2024. The estimated value of metal production in 2025 increased by 13 percent to $38.1 billion from a revised total of $33.6 billion in 2024. The total estimated value of industrial minerals production was $73.7 billion, 2 percent more than the revised total of $72.2 billion in 2024 (Table 1). Increases in production of certain nonfuel mineral commodities, along with increases in prices of some industrial minerals contributed to the overall increase in the total value of domestic nonfuel mineral production in 2025. For the industrial minerals sector, the production value of natural aggregates, which comprised approximately 60 percent of the total production value of all industrial minerals, increased by 4 percent even though production volumes decreased by 1 percent in 2025 compared with production in 2024. The largest percentage increases in production value in 2025, in descending order, were for dimension stone, wollastonite, potash, mica and portland cement. The largest percentage decreases, in ascending order, were for high-purity quartz, industrial sand and gravel, lithium carbonate, bromine and boron. For the metal sector, production decreased for several mineral commodities and prices decreased for several metals due to oversupply. Lithium, manganese and nickel had some of the largest percentage decreases in production value.

May 1, 2026

By C. R. Hayward, H. O. Hofman

I. INTRODUCTION. THE aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation: The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class may work as a whole, each member contributing his share to the solution of a problem, or the students may carry on investigations independently; the former exemplifies class-research; the latter, individual research. It is with a branch of the former, with special reference to ore-treatment that the present paper intends to deal. In smelting an ore by a well-established process, the result is shown by analyzing the products to see whether their compositions correspond to those calculated in making up the charge; by taking account of stock to show the distribution of metal in the different products made and the losses from dust and volatilization, by casting a thermal balance to find the ,distribution and losses of heat; and by making a cost-sheet to ascertain, as far as possible, the necessary outlay of money. In, lixiviation and amalgamation, the mode of operating has to be varied to adapt a process to the individual ore. Here a number of tests become necessary. Each will consist of a series of experiments with one variable, in order to find the conditions under which the variable gives the best result; a. summary of several tests will give the best method of operating.. Working a number of charges with the best method will furnish the data desired for ascertaining the recovery of metal,

Jun 1, 1909

By M. H. Chetrick

Since 1945, a commercial-scale pilot plant for the gasification of lignite has been operated by the Bureau of Mines at Grand Forks, N. Dak. The description, operation, and objectives of this pilot plant have already been described in previous reports (6, 7, 8). Although the experimental data obtained from the operation of the externally heated retort have been tabulated and summarized (1, 7), few studies have been made in the correlation of these data. The purpose of the present investigation was to review the data taken in tests of the lignite-gasification pilot plant and to correlate the gas-composition data in terms of their basic factors.

Jan 1, 1950

By Fathi Habashi

"On August 3, 1888, German Patent No. 43977 entitled ""A Process for the Production of Aluminum Hydroxide"" was issued*. The discovery which led to the patent was made by the Austrian chemist Karl Josef Bayer (1847-1904) (Fig. 1) who was at that time in Russia, and the process became known as the Bayer Process in his honour(1)(2)- The process imediately achieved industrial success, displacing the pyrometallurgical process that had been used until that time to produce alumina. The Bayer Process involved the pressure leaching of bauxite with NaOH solution to obtain sodium aluminate solution from which aluminum hydroxide was precipitated by seeding. Today bauxite is not only the principal source of aluminum but also of gallium, both metals being effectively recovered by the Bayer Process. The purpose of this paper is to outline the historical background of this discovery and its importance to hydrometallurgy."

Jan 1, 1999