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By W. H. Zieman

"THIS IS THE THIRD of the consecutive Annual Forums on Grinding that were instituted by Mr. L. E. Djingheuzian in 1957. The first was on the subject of Ball Milling (Transactions, Volume LX, 1957) and the second on The N on-Cataracting Ball Mill (Trans-actions, Volume LXI, 1958). From the discussions at these forums it was evident that one of the most important factors affecting the efficiency of grinding is the shape of the liners. In order to make a study of liners in use, it was •decided to seek the co-operation of operators across the country by sending out questionnaires requesting basic information. Additionally, these operators were urged to set down briefly any pertinent information on the subject acquired through experience and experiments at their own particular plants. A compilation and analysis of these data were to form a basis for discussion at the Forum on Liners at the Annual Meeting in Montreal, April, 1959. The response of the milling fraternity to this solicitation was most gratifying, and clearly indicated the importance attached by the operators to the effect of liner design upon overall grinding performance."

Jan 1, 1959

By Kiyoshi Shibata

A new assessment model has been proposed for metal production and its recycling system. The model consists of three processes, smelting of ore, cascading and upgrading of metal scrap. The present approach is to assess the total energy consumption of the system, by introducing two equations for describing the relationships between critical impurity content and the mass of production or scrap recycling. The total energy consumption in the system can be described as a function of recycling rate and performance of the upgrading process. The present model suggests that the impurity removal efficiency and yield in the upgrading process are essential to reduce the energy consumption in the systems. Especially, such points should be explicitly controlled in recycling of aluminum. The potential capability of this model was also discussed by obtaining several quantitative information required for the process design and the operational control of beneficial recycling of metals.

Jan 1, 1998

By Gurubasayya Swamy

This paper presents the performance study of sag mill in the processing of gold ore. Deterioting ore grade and high demand of metals has tremendously influenced the SAG mills. Today?s high capacity Semi-autogenous grinding (SAG) mills expand vast amounts of energy and in doing so consume tons of shell liners and steel balls, while processing ore. Semi-autogenous (SAG) mill performance is influenced by ball charge, feed properties, shell, grate, and pulp lifter design. In the performance study of SAG mill, based on the results obtained it can be observed that SAG mill performed better at feed size +4 inch and grinding media consumption 0.90kg/mt. In the present study the effect of crusher bypass on SAG mill performance, an immediate drop of throughput ranging from 10-20tph is observed. Keywords: sag mill, pulp lifters, grinding media, energy, consumption, throughput

Sep 1, 2012

By W. T. Westbrook

This Bureau of Mines report contains methods for analyzing iron are for total iron, ferrous iron, metallic iron, silica, manganese, aluminum, calcium, magnesium, phosphorus, titanium, carbon, sulfur, moisture loss, and ignition loss by wet chemical methods. Some are modifications of standard umpire methods; others have been developed by the Bureau of Mines to provide a com-bination of speed and accuracy. They are suitable for a high volume of samples and/or control situations, and for situations in which instrumental results must be verified. These methods have been used to analyze taconites, native ores, some foreign ores, and metallurgical products.

Jan 1, 1975

By R M. Arellano, D M. W Harney, M Makhuvha

Mineral resource and ore reserve estimates are founded on two sources of data: tonnage and grade. The tonnage is a product of volume and density; both of which are estimates. Density impacts numerous operational factors, which include, but are not limited to, mine design, mine planning, equipment selection and operational performance. Hence, density is a significant parameter and its determination requires similar care as the measurement of grade. Selecting an appropriate method to determine density, and ensuring its rigorous application, thus reduces risk and can improve operational performance, which in turn increases profit margin.Different Anglo American sites use a variety of practices and protocols to determine density, which is highly dependent on the physical characteristics of the orebody, local conditions and historical practices. Also, individual sites sometimes execute the same method in a slightly different way, which may also affect the outcome of the measurements. In order to gain a better understanding of how density is determined at Anglo American projects and operations, a review of these techniques was undertaken. The objective of the study was to identify and share good practices across the company, as well as to look for improvement opportunities, where applicable. Ten different methods of measuring density, applied to nine different commodities, were identified and described. An additional technique was recently developed by Anglo American Technical Solutions. The core pycnometer is a large gas displacement pycnometer capable of measuring density at high accuracy on full pieces of intact core.This paper provides an overview of methods used to determine density within the Anglo American Group, including quality control and quality assurance aspects. It is not the purpose of this paper to identify a preferred method, but to highlight the importance of choosing the best suited practice for a project or mine site. In addition, a case study comparing two different density determination methods applied to the same rock samples from the Los Bronces Copper mine was undertaken and the results of that study are presented here.Selecting the most appropriate method to determine density and comparing results from two or more techniques against each other, together with other suitable quality control procedures, is considered to be of utmost importance for all mining operations and exploration projects.CITATION:Makhuvha, M, Arellano, R M and Harney, D M W, 2014. Determination of bulk density in Anglo American plc, methods and impacts, with a case study from Los Bronces Mine, in Proceedings Ninth International Mining Geology Conference 2014 , pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By Patty Simpson, Sarah Benson

In an effort to improve consistency across the nuclear industry, over the past 10 years the Canadian Standards Association has developed a series of standards related to environmental management at Class 1 nuclear facilities and uranium mines and mills. Canadian uranium mines have been required by the Canadian Nuclear Safety Commission to align their existing monitoring programs with these standards. Orano’s McClean Lake Operation’s monitoring program, which was originally presented in the Environmental Impact Statement in 1991, has evolved through regulatory change, new scientific understanding, additional projects, and experience into a comprehensive set of monitoring requirements for effluent, groundwater, air emissions, and the receiving environment. The exercise of aligning the existing practices with the standards provided an opportunity to review and rationalize the entire program. To document the process the original “Environmental Monitoring Program Design Document” was restructured and developed as both a repository for historical information and monitoring rationalization, and also to be a living document describing on-going studies and supplementary work that are outside of the regular environmental monitoring program and may justify future changes to the program.

Jan 1, 2020

By R. H. King

Suboleski and King (1990) analyzed the reasons for the dramatic increase in underground coal mine productivity during the last 10 years. This paper examines whether this increase can be extended. The paper forecasts whether the mix of technological, procedural and other factors that produced the increase will change in the future. The forecast is based on the base case and spreadsheet production model described in the previous paper.

Jan 1, 1991

By Bao Xiancheng

Jinlong's copper flash smelting process started up in April 1997. In the early days of production, lots of equipment and process problems were encountered. But, through continuous improvements in equipment and operation, the designed productivity was reached two years later and the smelting operation has been greatly upgraded since then. After more than 4 yew of production, we have made great achievements, such as increasing the flash furnace availability, significant improvements in operation control, optimization of concentrate burner's structure and operation, and smooth operation of the whole smelter. This paper outlines Jinlong's operational achievements made after commissioning, and discusses problems that were encountered and their countermeasures. Operational experience is also summarized

Jan 1, 2002

By Ricardo Oliveira Gallart de Menezes, Claudio Gerheim Porto, Reiner Neumann

This study presents the results of the mineralogical characterization of Ti-Zr ore from the Jiboia deposit, located in the municipality of Brejo Grande, Sergipe State, Brazil. The goal is to identify the main Ti, Zr, and REE carrier phases in the different particle size fractions in order to subsidize the development of a cost-effective processing route for the production of heavy minerals concentrate. The mineral resources are estimated at 31.5Mt @ 3.5% of total heavy minerals (THM) for the Jiboia Ti-Zr deposit, of which 5 Mt @ 3.39% THM were classified as measured and indicated. The mineralogy of the heavy mineral concentrate recalculated to 100% is represented by 22% pseudorutile, 20% ilmenite, 15% zircon, 5% rutile, 2% monazite, and 36% gangue. The ore minerals are preferably concentrated in the 150 × 53-μm granulometric fractions, which represents 80% of the THM and only 27% of the ROM (Run-of-Mine) ore. Therefore, by cutting the ore to 150 μm, it is possible to discard 73% of the ROM mass and recover 80% of the THM, including 100% of the zircon and monazite which are the most valuable minerals present in the heavy mineral concentrate. The global recovery of THM starts to decline rapidly in the fractions finer than 106 μm and the mass disposal (tailing) does not follow in the same proportion. Higher zircon contents in the concentrates of the fractions finer than 150 μm imply a significantly lower recovery of heavy minerals like ilmenite, pseudorutile, and rutile that make the fractions coarser than 150 μm.

Jan 9, 2024

By Jay Nopola, Christopher Johnson, Matthew Minnick, Erik Hemstad, Erik Walega

Mining data collection, storage, and interpretation methods have progressively changed over time. Data collection, for the most part, has transitioned from handwritten notes and logs based on manual gauge readings to real-time data streaming through instrumentation capable of directly communicating with site-based data historians or cloud storage. Data collection and storage have had to adjust commensurately with the volume of data, leading to more complex database architecture. Geoscience interpretation methods have also changed; however, the first goals of modeling and understandings from first principles remain the same and are typically deeply rooted in historical academic work. Machine learning methods are becoming more common, available, and implemented by industry and practitioners. Despite the wide accessibility of machine learning methods, the population of geoscience subject matter experts in the underlying theory of this analysis type is limited. This form of analysis, therefore, must be conducted carefully and in conjunction with subject matter experts, on both machine learning theory and the field it is being applied to. This paper aims to provide background history on data analytics and machine learning, current methods and practices, and high-level geoscience case study examples, as well as take aways regarding the mining industry, potential pitfalls specific to geosciences, and possible perspectives on the direction of artificial intelligence in the future.

Jun 25, 2023

By J. Peterson

A review of blast designs and improved blasting practices at the Ekati??Diamond Mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine's well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. Ekati??uses 270mm holes for production blasting, and 165mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion / ANFO blends. The mine plan involves using 30m double benches. A 30m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15m benches. This paper summarizes the monitoring equipment and data gathered to date.

May 1, 2001

By A. V. Tarasov

The lack of technology for processing of sub-grade ore concentrates and intermediate products for extraction of Zn, Pb, Cu and precious metals at the metallurgical stage was a constraint for an increase in the production of these metals. The technology developed in the Gintsvetmet Institute is based on an improved electrothermal smelting process for treating calcined charge, ensuring thereby a reduction in power requirement and improving the environmental performance of the process. Electric smelting of sub-grade polymetallic concentrates produces lead bullion, to which the bulk of gold and silver reports, as well as well segregated matte and slag concentrating the bulk of zinc. Lead bullion and matte are commercial-grade products; zinc is recovered from high-grade (15% Zn) slag by slag fuming process. Reduced loss of precious metals in slag ensured by the given technology is attributed to the fact that the slag contacts with matte with low contents of gold, silver and lead, rather than with lead bullion. Limited amounts of off-gas typical of electrothermal processes ensure cost-effective operation of dust recovery devices and a reduction in emissions of harmful pollutants into the ambient air.

Jan 1, 2002

By Baohua Guo, Xuelin Yang, Tingkan Lu, Hailin Sun

The work presented in this paper mainly involves two parts. Firstly, the fundamental characteristics of the high pressure carbon dioxide gas fracturing technique (CO2 technique), including, a proposed method of TNT equivalence calculation, which is used to calculate the TNT equivalence of discharge of CO2 technique, and the comparison of the explosion volume generated by dynamite and expansion volume of liquid carbon dioxide is conducted to show the differences of fragmentation capacity between the two of them. Secondly, the coal seam fragmentation mechanisms of CO2 technique are proposed, including, 1) Gas jet cutting and penetration by shaped charge, 2) Gas volume expansion by changing phases of carbon dioxide, 3) Coal seam softening by destress blasting and 4) Coal seam fragmentation by discharge vibration, associating with the mechanisms, the equations for calculating fragmentation radius are developed and verified.

Jan 1, 2017

By Deborah McCombe

"By now, most geologists and engineers in the Canadian mining industry are familiar with National Instrument 43101 Standards of Disclosure for Mineral Projects (NI 43-101) and the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards for Mineral Resources and Mineral Reserves, which are incorporated by reference in NI 43-101. In recent years, significant progress has also been made in establishing standard reporting practices internationally that recognize the globalization of the industry and enable investors to compare projects anywhere in the world and make informed investment decisions. This article is part of a series that will summarize the background and development of international resource and reserve reporting standards by the Committee for Mineral Reserves International Reporting Standards (CRIRSCO), highlight its current activities and provide insight into international mineral reserve and resource reporting issues. CRIRSCO was formerly the Mineral Definitions Working Group of the Council of Mining and Metallurgical Institutions (CMMI), an organization representing professional bodies in all of the major mining and mining investment countries. In 2002, CMMI disbanded and CRIRSCO continued as a volunteer committee with limited funding from those professional bodies and increasingly from other sources, such as mining companies and regulatory bodies. CRIRSCO was adopted as a Task Force of the International Council of Mining and Metals (ICMM) in 2007. The ICMM is an influential industry body representing all of the major mining companies and many junior companies through its associated members, such as the Minerals Council of Australia, the Chamber of Mines of South Africa and the Prospectors and Developers Association of Canada. CRIRSCO now has funding to pursue its objectives."

Jan 1, 2003

By Q. G. Liu

New solid-state electrochemical sensors 1;.1sing Li2SO4-Ag2SO4 electrolytes have been developed to measure SO2 and/or SO3 in gas mixtures. Silver embedded in part of the electrolyte is used as the reference electrode. Although single-phase electrolyte sensors yield accurate results for one to two days, a two-phase electrolyte cell exhibits excellent long-term chemical stability. For example, stable and accurate potent iometric responses have been obtained over a six mo.nth period. The. advantages of the two-phase electrolyte ( 23 mol% Ay 2SO4 ) cell include excellent mechanical strength on temperature cycling and an insensitivity to compositional variations in the electrolyte and to temperature fluctuations. Experimental tests have shown excell.ent results in SO2-air. mixtures with the SO2 concentration ranging from 3 to 10,000 ppm (vol). However, the SO2 concentration range was limited by a lack of standard gas mixtures, and our sensor cells can be used to measure S02 concentrations significantly less than or larger than our experimental range. Results also indicate that the presence of significant concentrations of CO2 and H2O in the gas mixture has no effect on the sensor response. Thus the two-phase electrolyte ( 23 mol% Ag2S04) sensor has exceptional selectivity, reliability and long-term chemical and mechanical stability.

Jan 1, 1985

By H. E. Frimmel

Abstract - Most of the gold in the Late Archean Witwatersrand Basin is of detrital origin but, in its present form, it is metamorphosed. The only relict detrital features preserved are the morpho­logical characteristics of some placer gold particles. Regional burial metamorphism in the shallower and deeper levels of the Witwatersrand Supergroup reached temperatures around 300°C and 350°C at pressures between 2 kbar and 3 kbar, respectively , estimated from phase relations, chlorite-chloritoid exchange thermometry and chlorite thermometry . Metamorphism of the gold involved compositional homogenization of individual gold particles and partial recrystallization. Various infiltration events caused the partial mobilization of the gold at slightly lower temperatures, between 240°C and 300°C. These infiltrations can be related to crustal extension during the deposition of massive carbonate sequences of the Transvaal Supergroup (around 2.5 Ga), and later to the emplacement of the Bushveld Complex, and to the Vredefort event around 2.0 Ga ago. The mobility of the gold was dependent on the sulfur fugacity prevailing in a particular horizon which, in turn, was deter­ mined by the amount of pyrite (and other sulfides) present in that horizon. With the sulfur fugacity being controlled by stratigraphy, low fluid:rock ratios in a pyrite-rich horizon were most conducive for the mobilization of the gold. Thus, long-range gold mobilization in the Witwatersrand Basin can be expected to be the exception rather than the rule.

Jan 1, 1994

By K. A. Fowler, L. W. Higley

Steels with an alloying addition of depleted uranium were studied to develop successful melting , casting , and fabricating methods ; to obtain data on mechanical properties ; and to determine the effects of this alloying element . Uranium in amounts up to 1.5 percent was added to steel - base compositions containing approximately 0.5 percent carbon , 2 percent nickel , 0.25 to 2.0 percent silicon , and 0.75 percent manganese in both vacuum- melted and air -melted heats . Radiation levels were monitored for all operations . Bureau of Mines research at the Rolla Metallurgy Research Center showed that uranium additions did not increase tensile strength ; that hot - shortness occurred during forging above 1,090 ° C because of the presence of a low melting point constituent of a eutectic type ; and although a measurable amount of radioactive contamination resulted from processing , the quantity was never large enough to require the work area to be identified as a radiation area .

Jan 1, 1964

By B S. Petri, N T. Rouse

Underground limestone mines generally lack air pressure monitoring procedures and instrumentation guidelines. The blasting industry also lacks an applicable source for air overpressure levels that are produced by blasting operations in underground mines. This became apparent during the development of a new underground limestone mine, where overpressure levels from production blasting needed to be estimated. During the development phase of the mine, it was imperative that newly constructed underground structures be capable of withstanding the overpressure produced by blasting. Therefore, a study was conducted to (1) identify and review any published studies for data that may be applicable, (2) identify the appropriate equipment required to record the overpressure levels, (3) determine the proper procedures for setting up the equipment and recording overpressure, and (4) provide an understanding of the nature of the air overpressure in a developing mine.

Jan 1, 2014

By F. W. Schremp, V. L. Johnson

This paper discusses the results obtained from high temperature, high pressure filter loss studies in which field samples of clay-water, emulsion, and oil base fluids were used. High temperature, high pressure tests of some premium priced emrilsion and oil base drilling fluids show filter loss peculiarities that are not predicted by standard API tests. It is recommended that high temperature, high pressure filter loss tests be used to evaluate the performance of such fluids. Apparatus is described which proved to be satisfactory for evaluating filter loss behavior over a wide range of temperatures and pressures. INTRODUCTION The petroleum industry spends large sums of money each year on chemical treating agents for lowering filter loss and on premium-priced low filter loss drilling fluids. While it is an accepted fact that low filter loss is advantageous during drilling operations, it is questionable whether the present standard method of determining filter loss gives a reliable indication of the loss to he expected under bottom hole conditions. The purpose of this paper is to show that high temperature. high pressure filter loss tests Should be used to evaluate filter loss behavior of fluids for deep drilling. Concern over possible effects of filter loss on oil well drilling and well productivity dates back to the early 1920's. During the years 1922 to 1924, filtration studies were reported by Knapp,' Anderson2 and Kirwan." These studies were the first to be reported in the literature on this subject. No further information was published on the subject until 1932 when Rubel' presented a paper in which he discussed the effect of drilling fluids on oil well productivity. In 1935. .Jones and Babson constructed the first laboratory tester designed to study the effects of temperature and pressure on the filter loss behavior of clay-water drilling fluids. In a discussion of their investigations, Jones and Babsons stated, "Performance characteristics of a mud can he evaluated with considerable reliability by a single test at 2,000 psi and 200°F. Exact correlation between the results of performance test5 made under these conditions and the behavior of muds in actual drilling operations is of course impossible." Jones arid Babson apparently were well aware that at best laboratory tests can give only qualitative answers to the question of what is the actual behavior of a drilling fluid when subjected to deep drilling conditions. Jones' presented a paper in 1937 in which he described a static filter loss tester to be used for routine filter loss tests. This instrument subsequently was adopted as the standard APl filter loss tester. In 1938, Larsen7 developed a relationship between filtrate volume and filtrate time that is in general acceptance today. Larsen was cognizant of the danger of estimating bottom hole behavior from filter loss measurements at room temperature. He tried to predict the effect of temperature on filter loss by relating temperature effects through the temperature dependence of filtrate viscosity. This was undoubtedly an over-sirriplification of the temperature dependence of drilling fluid filter loss. In 1940, Byck" published a summary of experimental results of filter loss tests made on six representative California clsy-water drilling fluids. He concluded that "no existing method will permit even an approximate determination of the filtration rate at high temperature from data at room temperature. It is necessary to measure filtration at the temperature actually anticipated in the well, or to make a sufficient number of tests at various lower temperatures so that a small extrapolation of these data to the anticipated well temperature may be applied." Byck's findings were presuma1)ly well accepted and recognized by drilling Fluid technologists, and yet, they did not lead to wide adoption of high temperature drilling fluid filtration equipment. This is evidenced by the fact that no addition information has appeared in print on the subject since 194). Study of Byck's data shows that there was a useful consistency in them. The fluids did not show predictable losses at high temperatures, but they did line up at high temperatures in approximately the same order that they lined up at low temperatures. That is, if a fluid appeared to be a good fluid with relatively low loss at low temperatures, it would also be a good fluid with relatively low loss at high temperatures. In the last decade. the above situation has changed. The drilling fluid art is markedly different from what it was. The outstanding change, as far as the present discussion is concerned, has been the adoption of wholly new types of drilling fluids. Oil base and emulsion drilling fluids have come in to wide use. It is, therefore, necessary- to re-examine previously satisfactory generalizations to see if they are still valid. It turns out. as might have been expected. that Byck's explicit generalization. already quoted, is still true. Filter losses at high temperatures cannot be predicted from filter losses at low temperatures. However, no further generalizations are valid now. Fluids of different chemical types show different general behaviors. No longer do the fluids line up approximately the same at high temperatures as they do at low temperatures. They may line up entirely differently. Special fluids exhibiting very low loss at low temperatures may have losses as high as those of ordinary clay-water fluids at high temperatures. This fact is highly significant, because premium prices are being paid for the special fluids.

Jan 1, 1952

By E. Steiakakis, A. Athousaki

Nowadays, stakeholders have a strong say to the enforcement of best practices by mining and quarrying companies. In most cases there is a direct relationship between sustainable development principles and best practices. Mining companies try to apply best practices in order to sustain their operation without lost time and effort to litigation, and other obstacles. However, when and where there is a lack of state or regional mineral policy, or when the mineral policy is fragmented and touching on conflicting laws, mining operations may be subject to additional administrative hassles, and, thus, operators feel threatened and tend to apply best practices loosely. This paper argues that the only way that mining and minerals operations can be a source of development is to ensure that they are working within the framework of sustainable development. Furthermore, in order to follow the paradigm of sustainable development they would need to be guided by a regional, national or even transnational (i.e. European) minerals policy.

Jan 1, 2011