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By A. C. Johnson

The Bureau of Mines explored the Three Kids deposit in 1941 as part of a strategic minerals program. Earlier mining and exploration had established the presence of a substantial tonnage of medium-grade wad ore, and drilling and sampling by the Bureau of Mines, in collaboration with the Federal Geological Survey, indicated an additional tonnage such that development and exploitation became more clearly feasible. Private interests, with Government support, undertook to produce metallurgical-grade manganese. The present paper describes the Bureau of Mines exploration and subsequent development. Manganese in the Three Kids area is found in one of the lower members of the Muddy Creek formation in a bed of fine sandstone and silt, which outcrops around the north edge of the River Mountains and generally dips 20° to 40° away from the hills. There is considerable variation in the thickness and grade of the ore. The ore is light weight, having a density of 1.2 to 2.

Jan 1, 1956

By O. A. Orumwense

The liberation of intimately disseminated impurities from the coal matrix often demands that the material be ground to a high degree of fineness. Similarly, some technologies for coal utilization require superfine particles (i.e., sizes less than ten microns). This implies additional costs for coal preparation plants due to the high energy and media costs associated with fine grinding operations. Besides, there are problems such as sever product contaminations due to media wear and impairment of the quality of coal. Hence, proper choice of grinding media type is important from the viewpoints of cost reduction and product quality.

Jan 1, 1993

By D Baas, J Le, R Braun, R Chandramohan, K Hollis, G Lane

The Phu Kham Copper-Gold Operation (Phu Kham) is located in northern Laos, approximately 140 kilometres from the capital, Vientiane. The operation is a producing asset for Australian-based copper and gold producer, PanAust Limited (PanAust) and is operated by Lao-registered company, Phu Bia Mining Limited (Phu Bia Mining). PanAust holds a 90 % interest in Phu Bia Mining. The Government of Laos owns the remaining 10 %.The Phu Kham Operation has recently undergone a series of process improvements to treat the anticipated competent ores scheduled for 2017 and 2018. The operation’s comminution circuit, which comprises a semi-autogenous (SAG) mill and two ball mills, each with 13 megawatts (MW) of installed power, was expected to be SAG mill limited when treating competent basement rock. Ausenco Services Pty Ltd (Ausenco), was engaged to help optimise and enhance the productivity of the Phu Kham comminution circuit over an eight-month period. The work involved participating in and overseeing the redesign of the SAG mill liner systems and developing operational strategies for maximising throughput through to the end of mine life. Ausenco’s comminution optimisation tool, Ausgrind, was used to benchmark and analyse plant data with empirical models, predict circuit performance for varying ore characteristics and evaluate liner wear and predict the life for varying operating parameters. Variances between the actual and the predicted values were assessed in detail to identify missed opportunities, and guiding operating parameters were redefined to maximise throughput and productivity. In combination with the redesigned liner system, optimised process controls for varying ore competencies, and improved operational practices and troubleshooting strategies, increased Phu Kham overall production, exceeding the milling capacity when treating competent ores. CITATION:Chandramohan, R, Braun, R, Lane, G, Hollis, K, Le, J and Baas, D, 2018. SAG mill optimisation and increasing throughput at the Phu Kham Copper-Gold Operation – a success story, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 113–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

Discussion of the paper of Robert H. Richards, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 81, September, 1913, pp. 2299 to 2303. C. D. DEMOND, Anaconda, Mont. (communication to the Secretary*) :-Any one who has observed the increased efficiency of the Wilfley tables in a mill when fed from a reasonably good hydraulic classifier, as compared with tables fed from a spitzkasten., which is a very poor classifier, will agree to the advantage of ? better classification." It must be gratifying to Dr. Richards to know that, directly or indirectly, maim mill men are responding to his persistent advocacy of correct principles of ore dressing and are accepting the results of his investigations. As he says, these principles mean much for both the conservation of resources and the profit of operators. When Dr. Richards gives us accurate figures as to the maximum size of free mineral grains in the tailings of the Wilfley table and of the vanner, they will be of a good deal of practical value in delimiting the proper fields for the Wilfley, the vanner, and the round table. He has coined the terms ? free settling" and "hindered settling."' The series may be completed by adding "crowded settling," the main principle of action on both the vanner and the Wilfley table, which is the principle of separation in a mass of grains crowded as closely together as they can be and yet continue free to move between one another; and the occurrence of larger mineral particles in the Wilfley tailing than in that from the vanner is apparently caused by the more violent agitation, due chiefly to the purposely sudden reversal of the stroke. It seems likely that the agitation caused by the wash water dropping directly upon the concentrate on the vanner is more harmful than that due to the shake. For the very finest material that can be concentrated by usual methods, the round table is superior to the vanner because it does not, have even, the gentle agitation of the latter. The action on round tables is, not crowded settling," but "film sizing," 2 but agitation is harmful in the latter action. George Gates proved this harm 20 years ago : in slaking the first successful large-scale application of canvas tables in California gold mills he abandoned all shaking motion, although he had patented canvas tables to which such motion was applied.

Jan 11, 1913

By M. Hochenhofer

Due to economic aspects and environmental regulations recycling of slag and waste from ferroalloy production became a very important issue for the companies during the last years. The treatment of slag depends prior on the composition, especially on their content of valuable metals and impurities. The final aim should be a total re-use of these materials in the industry e.g. cement industry, pig-iron production etc.. Therefore, to reach the required physical and chemical properties for a further use, possibilities of a metallurgical treatment have been investigated. The conditioning of slag with a high V-, Mo- and P-content via reducing metal bath showed to be one alternative. To determine the optimal process parameters, practical investigations with different slag compositions and thermodynamic calculations were carried out.

Jan 1, 2006

By Slobodan Radosavljevic

The polymetallic W-Pb-Bi-Ag ore from the ?Nova jama? ore zone of the Rudnik ore field have been investigated. Contact-pneumatolytic (skarn), pneumatolytic-hydrothermal, and hydrothermal mineralization phases are defined in this ore zone. The most significant mineralization phase that gave compact ore bodies is pneumatolytic-hydrothermal phase. A relatively pure Mo-free scheelite is the only tungsten-bearing mineral. Lead minerals are mostly presented by Pb-Bi sulphosalts and much less with galena. The image analysis coupled with Energy Dispersive Spectrometry (EDS) analysis on a Scanning Electron Microscope (SEM) was applied to the characterization of a W-Pb-Bi-Ag ore as an efficient tool for mineral quantification. Results of EDS (Energy Dispersive Spectrometry) analyses gave the empirical formulae: Pb1.91Ag0.05Cu0.08Bi1.93S5 for cosalite, Pb0.98Ag0.03Cu0.05Bi1.99S4 for galenobismutite and galena Pb0.99Ag0.03S.

Jan 1, 2006

By Raúl Prebisch

Continuando con el análisis de la realidad latinoamericana, el presente texto señala los factores estructurales internos de la insuficiencia dinámica de desarrollo latinoamericano como la absorción productiva de mano de obra, el aumento de productividad y necesidad de nuevas inversiones, los motivos principales de la insuficiencia dinámica, acumulación de capital, el obstáculo de la tierra, el funcionamiento de la estructura social, la inflación y la estructura social, los tipos de capital extranjero y la planificación y funcionamiento del sistema económico.

May 1, 1964

By Susan Jacob

The heat of fusion of silver was measured using high temperature differential scanning calorimetry (HTDSC). Heating rate, sample mass, calibration standard and cover gas flow rate were varied to determine their impact on instrument accuracy and reproducibility. Good reproducibility was achieved in most of the runs. Accuracy was not satisfactory in most of the runs, though three runs gave results within 1.7%, 3.3% and 3.5% of the literature value, within the acceptable limits. A larger mass and higher heating rate tend to generate more accurate results.

Jan 1, 2006

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By M. J. Jackson

MIGRATOM is a third-generation PC-based computer program developed by the U.S. Bureau of Mines for geophysical tomography. Like its predecessors, BOMTOM and BOMCRATR, MIGRA TOM was developed to enable users to address a variety of mining-related problems by mathematically reconstructing the distribution of physical properties in a rock mass, using measurements of travel time or amplitude of wave energy propagated through the rock mass. Examples of applications include lithologic characterization, fracture detection, fluid monitoring, stress evaluation, and blast assessment. The resolution and accuracy of tomographic reconstructions generally depend very strongly on the geometry of source and receiver locations. In many practical applications, such as cross-borehole tomography, limited coverage results in nonunique reconstructions. MIGRATOM follows the precedent of BOMTOM and BOMCRATR in allowing the user to constrain the inversion, in order to reduce the nonuniqueness problem. A new approach to application of constraints implemented in MIGRATOM is based on fuzzy logic techniques. Refraction of wave energy is modeled in MIGRATOM using an approach based on Huygens' Principle. Propagation of a continuous wavefront is modeled as a constructive interference phenomenon, which obviates the shadow-zone problem that affects conventional ray-tracing calculations. MIGRATOM has been tested with both synthetic and field data sets.

Jan 1, 2010

By Michelia Alba, Ronaldo S. Sampaio, Davi S. Braga, Mathieu Dubé

Climate change is pressuring industries and governments for decarbonization commitments, research, testing, and use of best practices to achieve the target of global warming below 1.5/2 °C. As it accounts for as much as 7% of all global CO2 emissions and 7% of energy consumption, the steel sector needs to address this issue with extended efforts. This paper provides information on the key potential of renewable biochar as an alternative fuel for pellet production. It also summarizes the successful application of biochar in a pioneering case study as the main fuel for a Grate-kiln pellet plant in Brazil, as well as the study of its use to replace coke and anthracite as an additive for iron ore pellets and other possible applications in the steel industry in COREM's precompetitive research & innovation program. The final discussion reveals the large quantity of biochar required by the Brazilian and Quebec scenarios for reducing CO2 emissions of iron ore pelletizing plants.

Jan 1, 2023

By G. S. Farnham

Abstract This paper lists the interests of the Physical Metallurgy and Chemical Research laboratories of the Metallgesellschaft, which were visited by the authors, members of a group of Canadian investigators sent to Germany by the Department of Reconstruction in 1945. The Physical Metallurgy Research Laboratory The following information was obtained from Professor E. Schmid, Chief of the laboratories. It is understood that Dr. Schmid is a former Nazi and was to be removed from his post in November (1945). Aluminium Research The laboratories investigated the corrosion resistance of the high-strength aluminium-magnesium-zinc alloys. The same test procedure as used by V.L.W. was followed and Dr. Schmid co-operated closely with Dr. Brenner on this project. Intercrystalline corrosion was combatted by additions of chromium, titanium, or vanadium, and the work in this field parallels that of Dr. Brenner of V.L.W. * Dr. Schmid reports that Bollenrath and Siebert believe that corrosion difficulties with these alloys can be overcome to some extent by heat treatment. He himself was of opinion that the correct answer lay not only in correct alloying but also in correct heat treatment. The heat treatment involved either interrupted quenching or a change in quenching rate from a solution temperature of 500°C. The procedure is either a slower cooling from solution temperature or an interrupted cooling with a holding period at l50°C. Work had been done on piston alloys, the 11-13% Si, 1% Ni, 1% Cu, and 1% Mg being the favoured material. This is called Lo-Ex and is similar to Mahle 124 or KS1275.

Jan 1, 1946

By Erdal Ünal

The computer program introduced in this paper is based on design guidelines developed for selection of support systems used in mine roadways. The support types considered include rock bolts as well as rigid and yieldable steel arches. Using the computer program, the design engineer can select the type, pattern and specifications of the support systems suitable for various roof conditions. The concepts utilized, assumptions made, support selection criteria and description of the computer program, developed for the PC, are included.

Jan 1, 1989

By G J. Harbort, Z Pokra

It has been observed in several Jameson cell installations where the source for flotation feed is deslime screens, that the recovery of coal particles greater than 0.5 m is not as great as that of finer material. Consequently, a research project was undertaken at a CHPP in the Bowen Basin, Queensland, to assess the possibility of increasing the recovery of coarser particles (+0.5 mm) within the downcomer of the Jameson Cell. The effect of decreasing turbulence and agitation in a commercial-scale downcomer was investigated to assess the effect on the recovery of both coarse and fine coal particles. This paper details the findings of the testwork, summarising the results relating to differences in the operating parameters within the downcomer.

Jan 1, 2005

By E. Yigit

Hydrometallurgical production of zinc from concentrates is generally carried out by H2SO4 leaching. For the smooth operation of this process, some harmful components must be removed from the leach solution before the electrolysis stage; MgO is one of these compounds. Zinc concentrate samples from the Mount Isa mines were used in leaching tests. Leaching tests with an aqueous solution of H2SO4 and SO2 gas were carried out at various temperatures, pH levels and leaching durations. While duration and the pH value of the solution were effective parameters in H2SO4 leaching, temperature and pH were more effective in SO2 leaching for the removal of MgCO3 and CaCO3. Removal of MgCO3 and CaCO3 was generally achieved at low pH values. The results show that SO2 gas can be a good alternative to sulfuric acid in the leaching of MgCO3 and CaCO3

Jan 1, 2010

By Sahoo K. C

Traditionally, the blast furnace (BF) has maintained a dominant position as the primary source of iron units. Notwithstanding the efficient nature of the process in respect of its material and energy consumption, the conventional blast furnace route is faced with limitations such as stringent quality metallurgical coke, high capital investment, etc. While BF will continue to retain its predominant position as the foremost ironmaking technology, the alternate processes may also have a role to play. Direct Reduced Iron (DRI) or sponge iron industry is all set to take a firm root in India as one important solution to the problems of shortage of metallurgical coal and ferrous scrap and high investment costs faced by the country's steel industry. The commercial proven DR processes coupled with electric arc furnace (EAF) steelmaking have also offered a viable alternative to the blast furnace - basic oxygen furnace (BF - BOF) route for the installation of integrated plants under specific local conditions. The performance and efficiency of DRI processes mainly depend upon the chemical and physical behaviour of the raw materials especially the iron bearing materials. Iron oxide pellet and sized lump ore constitute the oxide feed stock, while pellets form an ideal feed stock for direct reduction, use of lump ore is economically advantageous because of its lower price. National Mineral Development Corporation Limited (NMDC), being one of the major producer of iron ore in the country since last four decades, has established technology and developed process flowsheets for production of suitable calibrated lump ore for DRI production, besides supplying the natural lump ore for conventional blast furnace requirements. In addition to the above, extensive pilot plant tests have been carried out at the R&D Centre of NMDC for preparation of iron ore concentrates suitable both for direct reduction and blast furnace grade pellet feed using the iron ore fines from its own mines and as well as from the other iron ore mines in the country. For utilisation of the huge quantity of slimes generated in its ore processing plants, NMDC has planned to set up the first commercial plant adopting the smelt reduction process (ROMELT Process) for production of pig iron from Bailadila slimes. The paper mainly deals with various beneficiation techniques adopted for production of DRBF grade pellet feed from iron ore fines. Also presented in the paper, the extensive work carried out at R&D Centre on preparation and evaluation of calibrated lump ore (Natural Pellets), based on which, suitable modifications are incorporated in the ore processing plants of NMDC for production and supply of the same to sponge iron industries.

Jan 1, 1999

By Jean-Michel Rendu

That you are giving the Daniel C. Jackling award to me is a great personal honor. But more significantly, it is a recognition that geostatistics has come of age. And since I am considered by many as belonging to an older generation of geostatisticians, I thought that it would be fitting that I reflect on where geostatistics came from and where it might be going. First, though, let me propose a definition of geostatistics. Etymologically, paraphrasing Webster's definitions of "geo" and "statistics," it is "a branch of mathematics dealing with the collection, analysis, interpretation and presentation of masses of numerical data taken from the earth." This definition is most appropriate in the context of mining geostatistics. It includes both classical and spatial statistics. It emphasizes the earth aspect, or the analysis of geologic features. And it should remind the practitioner that geologic input is a critical part of all geostatistical applications. In the 1910s, statistical methods were already used to analyze geological data. However, the origin of geostatistics, as we know it today, is best set in the late 1940s, when H.S. Sichel recognized the lognormal distribution of sample values in the South African gold mines. In 1951, Daniel Krige observed that "it can be expected that the gold values in a whole mine will be subject to a larger relative variation than those in a portion of the mine." In other words, samples taken close to each other are more likely to have similar values than if taken farther apart. This observation is the foundation on which spatial statistics, which characterizes values defined in a multidimensional space, is built. However, the 1950s were marked by studies based on classical, as opposed to spatial, statistics. It was only in the 1960s that the need was recognized to model the similarity between sample values as a function of the distance between samples and that the semivariogram was defined. A theoretical framework was developed by Matheron that supplied an elegant mathematical explanation to the empirical observations made by Krige. Matheron coined the term "kriging" in recognition of Krige's pioneering work on the geostatistical evaluation of mineral deposits. As soon as this theoretical framework was developed, it was possible to bring geostatistics to the academic world. The "Centre de Geostatistiques" was founded in Fontainebleau. Numerous students were trained there, disciples eager not only to improve the theory and develop more sophisticated mathematical tools, but also to spread the new faith throughout the world. Expansion of geostatistics exploded in the 1970s, arguably the most fertile decade if it is judged by the frequency of theoretical breakthroughs, the number of original publica-

Jan 1, 1995

THERE are three objectives in translation of works of this character : to give a faithful, literal translation of the author's statements ; to give these in a manner which will interest the reader ; and to preserve, so far as is possible, the style of the original text. The task has been doubly difficult in this work because, in using Latin, the author availed himself of a medium which had ceased to expand a thousand years before his subject had in many particulars come into being ; in consequence he was in difficulties with a large number of ideas for which there were no corresponding words in the vocabulary at his command, and instead of adopting into the text his native German terms, he coined several hundred Latin expressions to answer his needs. It is upon this rock that most former attempts at translation have been wrecked. Except for a very small number, we believe we have been able to discover the intended meaning of such expressions from a study of the context, assisted by a very incomplete glossary prepared by the author himself, and by an exhaustive investigation into the literature of these subjects during the sixteenth and seventeenth centuries. That discovery in this particular has been only gradual and obtained after much labour, may be indicated by the fact that the entire text has been re-typewritten three times since the original, and some parts more often ; and further, that the printer's proof has been thrice revised. We have found some English equivalent, more or less satisfactory, for practically all such terms, except those of weights, the varieties of veins, and a few minerals. In the matter of weights we have introduced the original Latin, because it is impossible to give true equivalents and avoid the fractions of reduction ; and further, as explained in the Appendix on Weights it is impossible to say in many cases what scale the Author had in mind. The English nomenclature to be adopted has given great difficulty, for various reasons ; among them, that many methods and processes described have never been practised in English-speaking mining communities, and so had no representatives in our vocabulary, and we considered the introduction of German terms undesirable ; other methods and processes have become obsolete and their descriptive terms with them, yet we wished to avoid the introduction of obsolete or unusual English ; but of the greatest importance of all has been the necessity to avoid rigorously such modern technical terms as would imply a greater scientific understanding than the period possessed. Agricola's Latin, while mostly free from mediaeval corruption, is somewhat tainted with German construction. Moreover some portions have not

Jan 1, 1950

By Liu Run, Jia Zhao-lin, Yan Shu-wang

"Piles with diameter larger than 2m in engineering can be defined as large diameter pile, and piles used for oil platform foundation in Bohai Gulf, are usually over 100m long and 2m in diameter. Such long piles have to be manufactured by segments before installation, because of transformation and hoisting difficulties. The segments of the pile are assembled by welding during installation one to another. Normally, assembling two pile segments takes one day or even a longer time, which mainly depends on construction conditions. After pile segment assembling, it proves to be difficult to restart the successive penetration. The mechanism of pile refusal is discussed and the process of driving a segmented pile is simulated with a finite element program. The calculating results show that, when the stick-up stability was satisfied, increasing the length of the last segment of the pile and assembling the pile segments when the pile tip penetrates into a clay layer could greatly ease the difficulty of driving the pile. Furthermore, cutting down the pile extension time is also one of the most effective measures to minimize the refusal risk.1. InstructionIn recent years, more and more oil platforms with six or eight legs have been adopted in Bohai Gulf, China. The leg piles with diameters of 2m or more have to be driven to about 100m below the sea bed. Such long piles have to be manufactured by segments before installation, because of transportation and hoisting difficulties. The segments of the pile will be assembled during installation, in which a successive segment will be attached to a formerly penetrated one by welding (Fig.1). The assembling work often takes one day or even a longer time."

Jan 1, 2014

By Henry P. Cole

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/technical workplaces are described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training is explored. Research and development activities that may improve mine health and safety training are suggested. Most of these research and development activities were completed later in the project. This additional work is reported in the project technical report #2 and the final report. The research reported in the present document was completed in 1984 -85. Many of the initial findings reported in this document are updated in the later project final report.

Jan 1, 1988