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By T J. Napier-Munn, T Perkins

The JK Drop Weight test was developed at the Julius Kruttschnitt Mineral Research Centre (JKMRC) in the early 1990s as a means of characterising ore for the purposes of AG/SAG mill and crusher modelling. It has since been used extensively worldwide in the minerals industry as a key ore characterisation test which produces parameters which are used in comminution circuit design and optimisation. The test generates three parameters which are used in the AG/SAG mill model of the JKSimMet software. The resistance of the ore to high energy (impact) breakage is quantified with the A and b parameters. The oreÆs resistance to low energy (abrasion) breakage is measured using the ta parameter. The accuracy and precision of the results of the JK drop weight test are of great importance given that the parameters are key inputs in the design of such capital intensive items as SAG mills. Plant optimisation exercises also rely on the accuracy of the parameters to assist with improving the performance of an existing circuit. A thorough analysis of the accuracy and precision of the parameters generated by the JK drop weight test has now been undertaken by JKTech Pty Ltd (JKTech). An experimental program was designed using statistical methods to plan a hierarchical set of 24 drop weight tests on homogeneous material. Each stage of the test was identified and incorporated into the experimental design so that the contribution to the overall error of each stage could be quantified, including the effect of operator. The data were analysed by nested analysis of variance. An overall analysis of the A, b and ta parameters generated from the test program has now quantified the variance of these parameters more thoroughly than ever before. Using the results for the impact parameters, an analysis has been carried out to investigate the effect of these variances on final SAG mill comminution circuit design. The results will also be used to refine the comparative testing procedures currently in use by licensees worldwide.

Jan 1, 2008

By Mike Higgins

"The purpose of mining and its related industries is the removal of, and usually the subsequentprocessing of, material from the earth. This includes mining for minerals, quarrying for stone, and civilexcavations. Where this involves rock, the most common method is to fragment the rock by blasting. "

Jan 1, 1997

By R D. Morri, D J. Alexander

The design and optimisation of mineral flotation circuits is currently performed using a combination of laboratory, pilot plant and full scale testing. Owing to the variable nature of flotation circuits and the complex nature of the flotation process, it is difficult to interpret the data collected from flotation testwork. JKSimFloat is a computer modelling package which is being developed to interpret flotation testwork data collected at the various stages of the mining cycle. The parameters derived from the program can be used to assess potential circuit configurations in both the design of new flotation circuits and in the refinement of existing operations. The aim of this paper is to outline the modelling methodology used in JKSimFloat and to outline how it can be used effectively to model data collected from either the laboratory, the pilot plant or the existing flotation circuit. The use of flotation model parameters in circuit evaluation will be demonstrated via the use of a case study based on data collected from ComincoÆs Red Dog lead flotation circuit.

Jan 1, 1998

By A. L. Irwin

THE problem of compensation for labour is probably the oldest and most complicated one in history. The wage that a man receives is possibly the most concrete thing he gets out of his job and, rightly or wrongly, is generally considered by him to be the most important item in connection with his daily work. How today workers in an equitable way has been the study of industrialists for many years, and a great number of ideas have been tried out in an effort to arrive at a reasonable solution of the question. The idea of establishing a measuring stick for various types of work has intrigued industrial management for a long time and, after considerable study, the principle of Job Evaluation has taken form unti1, at the present time, it is becoming increasingly useful to industry at large. Job evaluation is a plan which is used to determine the relative worth of occupations by means of arbitrary measuring scales. These scales are developed for individual industries and are generally 'tailor made' for each particular case. There are as yet no absolute methods of measuring the work done by human beings and, as a result, one has to depend on comparative values to arrive at conclusions. However, job evaluation has provided us with a basis of negotiation for wage rates which is more satisfactory than mere guess work or persona! opinion. It supplies a common ground for discussion which is understandable by all taking part and ensures that thinking with regard to wage setting is carried out along standard lines.

Jan 1, 1943

By Eric Jacobs

"Building and operating tunnels has been a highstakes endeavor in terms of costs, complexity, safety and impact on contractors, owners and the public for a long time. There are many variables that need to be closely monitored and managed to construct a tunnel on-time, on-budget and safely. Once built, there are also many elements that need to be monitored and managed to operate a tunnel safely and efficiently.Fundamentally, the risks to the safe and efficient construction and operation of a tunnel are a function of the degree of harm and the likelihood of the harm occurring. From a cyber security perspective, risk assessments used to inform decision makers and support risk responses are typically based on identification of relevant threats; internal and external vulnerabilities; the impact that may occur given the potential for threats to exploit vulnerabilities and the likelihood that harm will occur. This article focuses on creating awareness of vulnerabilities associated with technology used in tunnel construction and operation and some of the challenges associated with remediation of these vulnerabilities. As we all know, technology has been evolving at an accelerating pace and infiltrating every aspect of our lives in new and often exciting ways. In the world of tunneling, sensors and systems that provide position and time have become accurate, rugged and cost-effective enough to come out of the research labs and into the equipment and systems used every day. There are many opportunities to employ connected computing devices and sensors to costeffectively capture, integrate and analyze key data with minimal latency to manage risk better, improve safety and avoid surprises."

Jun 1, 2019

By AIME AIME

THE John Fritz Medal Board of Award, at its annual meeting on Jan. 21, 1921, awarded its gold medal and diploma to Sir Robert Hadfield for the invention of manganese steel. On June 1, announcement was made that the Board of Award had awarded its gold medal and diploma to Charles Prosper Eughe Schneider for "achievement in metallurgy of iron and steel; for development of ordnance, especially the 75-mm. gun, and for notable patriotic contribution ' to the winning of the war." The award to Sir Robert Hadfield is for the year 1921; the award to Mr. Schneider is for 1922. The latter was made at this time in order that the medal might be presented by the group of American engineers now visiting England and France.*

Jan 1, 1921

"What is your history and how did you get involved in mining?Like many SME members, I came from a mining community with a family history in mining, in my case Walkerville, MT. Both of my grandfathers were underground miners. My father was a miner for a short time. He later sold drinks to the miners. Unfathomable by today’s standards, my dad would pick up the miners’ checks at the pay office and have them cashed and waiting with a shot and beer for the miners when their shift ended. My mother was a nurse, who from time to time, would patch up an unfortunate miner. I remember walking past multiple picket lines on the way to and from grade school, watching homes being boarded-up. I grew up with a deep respect for the critical relationship between labor and management.I had no intention of going into mining and initially set out to pursue a career in chemical engineering. But I attended my first two years of engineering at Montana Tech, due to the proximity and affordability. This is where I met Dr. Tom Finch, a mining professor who taught statics to the engineering students. After a coaching session in a hallway, half way through my sophomore year, I switched to mineral processing engineering. In his colorful way, Professor Finch advised me that, “You do not want to make #@*!! erasers and #@*!! Jell-O the rest of your life go talk to the guys in mineral processing.” He was very persuasive and here I am today.How about your involvement with SME?I encountered SME out of school and a little later in my career. Terry Maio and Jim Arnold invited me to local section meetings in the Missouri Lead Belt. That was my first exposure to the technical programming and relationship building that was possible at the local level. After Ozark Lead shut down and I relocated to Nevada, Rich Johnson, Scott Barr and Dave Collins encouraged me to attend my first annual meeting in Salt Lake City, UT. I joined SME at that time and was fortunate to be engaged by members like Art Schweizer and Jim Arnold, and I soon began the leadership progression for the Mineral & Metallurgical Processing Division. Since then, I have supported SME at the national and the local level serving in multiple roles and capacities."

Mar 1, 2017

What is your assessment of the status of the mining industry as we see some evidence of an economic recovery? I am optimistic about the short and midterm prospects for the industry and, hence, for the professionals in the industry that constitute the majority of the SME membership. All who will read this interview recognize that the quality of life we enjoy today is largely a result of our achievements in the mining and minerals processing sectors. I believe that the sustainability of that quality of life and the aspirations of other sectors of the global community to attain that same lifestyle will significantly depend on the continued successes of these industries. Looking at some of the traditional economic indicators, we see predictions of continued increases in gold prices during the next 12 months as a new round of quantitative easing keeps real interest rates low and drives excess capital flows from countries with trade surpluses - who have traditionally parked their money in U.S. government bonds - into other investable assets, such as gold. On the fuel side of the industry, we have during the last decade seen a steady rise in the cost of coal, and some of the recent spot prices have seen dramatic increases. Some suggest that coal prices may rise sooner than anyone expects, as global reserves are revised downward. This is based on the hypothesis that some of the main coal-producing countries are overestimating supplies and that coal prices could start rising far sooner than anyone thinks - with obvious serious implications for energy policy. Those forecasters note that, for the past couple of decades, global supply has been dropping at a faster rate than consumption.

Jan 1, 2011

By AIME AIME

A CERTAIN area in the State of Indiana seems to be a breeding place for presidents and near president about eighteen miles southeast of Elwood is the little village of Daleville, and there, on April 9, 1890, John Robert Suman, newly elected President of the A.I.M.E., was born. It was not long before he migrated to California, however, where he went to the Los Angeles High School, then for two years to the University of Southern California, after which he went up to Berkeley

Jan 1, 1940

By V. V. Zubkov

The systems of geophysical monitoring have been already put into operation at coal mines and ore mines. Since at present it is rather difficult to conduct mine experiments; it is necessary to start a new step in joining of geomechanics and seismic. The linking geomechanical and geophysical monitoring at coal mines and ore mines today became possible due to progress in development of numerical methods of modeling of stress state and technology for processing of seismic information. This paper describes one potential step in linking geomechanical and seismic monitoring at coal mines and ore mines.

Aug 1, 2013

By Sazol Das, Hany Ahmed, Ganesh Bhaskaran, Zhuoru Wu

"Friction stir welding (FSW) process in lap configuration for dissimilar materials has been developed and tested for steel to aluminum joining. A novel cylindrical tool was designed for improved material flow. The joining of steel to high strength 5xxx and 6xxx aluminum was carried out by FSW technique using optimized process parameters. The microstructure, micro-hardness, joint strength and corrosion properties at the weld interface have been investigated. Optical and scanning electron microscopy reveled a well layered structure at the interface and lap shear tests of the welds showed excellent fracture resistance. Neutral salt spray tests for up to 500 hours (ASTM B117) were carried out on the bare steel to aluminum FSW joints, which did not show neither evidence of corrosion at the weld interface, nor any degradation of the weld strength. The FSW lap configuration was applied to prototype commercial vehicle structural component whereby a steel stiffener insert was friction stir welded to high strength 6xxx aluminum alloy. The interface microstructure showed layered root without any steel shattering in aluminum side. A finite element study was carried out to quantify the benefits where it was found that the stiffness increases by 76% under bending loads and 36% in torsion loads.INTRODUCTION Energy preservation and environmental issues, namely carbon footprint and legislation around emission in transportation industries has led to a growing need to use of lightweight materials such as aluminum and magnesium alloys along with various grades of steel in structural application, while still maintaining their strength and crashworthiness. Assembling dissimilar materials within integrated structure is thus a stringent requirement related to optimum performance. In order to achieve an efficient technology of joining dissimilar materials such as aluminum to steel, it remains difficult to select an effective welding process for a given joint configuration. The use of aluminum in transportation industries for structural component is not exclusive in a design and is almost always used along with various steel grades for a mixed materials solution, thus dissimilar aluminum/steel lap joining is of great interest since this is widely used in the assembly of parts (e.g. pillar, frame rails, chassis, body in white (BIW), CAB, etc.)."

Jan 1, 2018

By AIME AIME

IN RESPONSE to a request from the president- elect of the Institution of Civil Engineers of Great Britain, Mr. Calvin W. Rice, secretary of the American Society of Mechanical Engineers, prepared a brief history of the joint activities of engineering societies in the United States, from which we have taken the following facts. National Societies Our first joint activities were in collection with the celebration of the eightieth birthday of "Uncle John" Fritz in 1902, and it is of interest to note that two of the members of the original celebration committee, Messrk. . Ambrose Swasey and Jesse Merrick Smith, will be members of the official deputation to England in June. Mr. Rice, also,' was .a member, of the original committee.

Jan 1, 1921

By AIME AIME

THE Iron and Steel and Institute of Metals Divisions will meet jointly at the Statler Hotel, Detroit, Oct. 4 and 5, during the Metal Congress, Oct. 2-6. The Wire Association, the American Welding Society and the American Society for Steel Treating, together with the two Divisions of the Institute, constitute the Congress this year, and each body offers an interesting technical program. The National Metal Exposition will, as usual, be held concurrently. Visiting metallurgists will find themselves engaged in a bit of research not listed in the program-a time study of how best to exploit in a few days both the Congress and all that the place of meeting has to offer. For Detroit, the beautiful "City of the Straits," is third in rank industrially in the United States, and its great manufacturing plants offer much of metallurgical interest. This is especially true of the automobile plants which will be open to members of the various societies during the week of the Congress.

Jan 1, 1933

By P. H. S. W. Kulatilake

The presence of discontinuities strongly affects the mechanical and hydraulic behavior of rock masses. Joint geometry networks play a vital role in civil, mining, and petroleum engineering projects associated with jointed rock. The need for a realistic representation of joint geometry in rock masses has been recognized. The first part of the paper shows how to build three-dimensional stochastic joint network schemes and also shows how to perform validation studies for these schemes using joint data from the Stripa mine, Sweden. Due to the existence of complex joint patterns, mechanical behavior of jointed rock masses usually exhibit scale effects and an-isotropic properties. A correct understanding of the mechanical properties (strength and deformability) of jointed rock masses is important for designing and performance estimation of structures build in and on rock masses. Beyond a certain volume, the mass proper-ties of the rock may remain essentially constant with respect to the effect of joints. This minimum volume may be used as the element size to represent the equivalent properties of a statistically homogeneous rock mass volume which contains a significant number of joints. This volume may be termed as a "Representative Elementary Volume" (REV) and may be of great importance for engineering purposes. Investigations are underway at both the 2D and 3D levels to look into the possibility of establishing relationships between REV mechanical properties and joint geometry parameters. Recently developed joint geometry modeling schemes are linked with existing distinct element codes (both 2D and 3D) to create a stochastic/deterministic stress analysis approach in achieving the goal. Results obtained so far in this direction are presented in the second part of the paper.

Jan 1, 1992

By Earle C. Waite

THE Industrial Minerals Division this year held no individual sessions of its own except the business meeting Tuesday afternoon. One session was held jointly with the Society of Economic Geologists, one with the Milling Methods Committee, and two with the Society of Economic Geologists and the Mining Geology Committee. At all of these meetings the attendance was better than usual and the Tuesday afternoon session, with nearly 400 present, probably set a new record for the Division. Joint sessions seem extremely popular when papers of mutual interest are presented. On Monday afternoon, mica was the predominating subject. The North Carolina mines provided most of the information presented, although the discussion brought out similarities with the New England mines. B. C. Burgess particularly stressed the fact that with the existing curtailment of mica from India it is necessary to get the most mica in the shortest time from the mines in this country. He said that the Colonial Mica Corp. hopes to have 1000 mines operating in the near future. This seems a great number, but when one considers that these mines employ from 3 to 28 men, mostly nearer the low figure, the output of each mine is relatively small. Although the price of mica is from six to ten times the prewar price, the yield of 8 to 150 lb. of mica per ton of raw ore does not provide high returns to the producer.

Jan 1, 1943

By Ross D. Lawrence

"IntroductionOne of the methods used when applying the Market Approach to the valuation of a mineral exploration property is known as the Joint Venture Terms Method. The method is particularly useful for the valuation of early-stage exploration properties. Unfortunately, valuators are sometimes imprecise in distinguishing between joint ventures and other types of transactions.At VALMIN '94, Bob Appleyard1 proposed that, if one ignores the time value of money and the probability that the expenditure commitment would be completed, the formula to calculate the value ($V) of a property owned by Party B at the time of the deal would be:$V =$Ex (100-1%)/1% (Formula I)Where $V is the value of the property2Where $E is the expenditure commitment by Party A, andWhere 1% is the percentage property interest to be earned by party A.At PACRIM '99, Mike Lawrence and Graham Dewar3 referred to this method and suggested that there was an ambiguity in the formula proposed by Appleyard in 1994. Mike Lawrence referred to this problem again at VALMIN '014•Lawrence & Dewar suggested that the formulashould be:$V100% =($Ell%) x 100 (Formula 2)Where $V 100% is the value of the entire property,Where $E is the expenditure commitment by Party B, andWhere 1% is the percentage property interest to be earned by Party B.Subsequently, there has been considerable discussion in the AuslMM Bulletin5. In my view, this discussion has touched on a number of useful points, but generally has overlooked one essential element needed for an understanding of the correct application of the N Terms method. That essential element is to understand that there is a material difference between (1) entering into a joint venture arrangement and (2) the purchase of an interest in a property."

Jan 1, 2003

By Achilles Dutra, Everton Santos, José Oliveira

The beneficiation of phosphate ores by froth flotation is the most efficient process used to separate apatite from gangue minerals like calcite, dolomite and quartz. However, the similarity of surface properties between apatite and calcite generally lead to non-selective adsorption of reagents, rendering the selective separation of these minerals a worldwide problem. The phosphate deposit of Itataia, State of Ceará, Brazil, studied in the present work, presents a complex mineralogical composition having uranium associated with the apatite mineral. The main gangue minerals are calcite and quartz. The bulk flotation of apatite and calcite with anionic collectors in an alkaline medium followed by the selective flotation of calcite at pH 5.5 using phosphoric acid as well as citric acid as depressant have been suggested for this ore. This paper presents the results of contact angle measurements obtained using jojoba oil, a natural reagent composed mainly of gadoleic acid (C20:1) and long-chain fatty alcohols (eicosenol and docosenol), as an alternative collector for the selective separation of apatite and calcite minerals. The hydrophobicity studies were carried out using a computer controlled contact angle goniometer. Additionally, the collector adsorption was evaluated via electrophoretic mobility and FTIR measurements. The results indicated that a high selectivity can be obtained by using jojoba oil as collector in a slightly acid pH range, without the use of depressant. The best results were achieved with a jojoba oil concentration of 200 mg.L-1 at pH 6.5, where the apatite was fully hydrophilic and calcite showed a high hydrophobicity (? > 60 º).

Jan 1, 2014

"The Australasian Joint Ore Reserves Committee (JORC), which is sponsored by the Australian mining industry and its professional organisations, developed the JORC Code to provide minimum standards for public reporting. JORC was first published in 1989 and later incorporated into the Listing Rules of the Australian and New Zealand Stock Exchanges making compliance mandatory for listing public companies in Australia and New Zealand."

Jan 1, 2003

The JORC Code contains a mandatory classification system for Mineral Resource and Ore Reserve estimates for public reporting. The classification is a statement of the Competent PersonÆs confidence in the estimate and an attempt to convey that confidence to the various users of the resource estimate. In general the classification process is either largely subjective, relying on the Competent PersonÆs experience, or relies on statistical measures derived from the estimation process, or is derived from an estimated level of confidence in the outcome. However, the statistical measures may not necessarily relate to the overall confidence in the resource or reserve which must take account of the confidence in the geological inputs to the estimation.In addition to the traditional deterministic interpretation and estimations adopted by geologists, semi-quantitative techniques are now available to improve the estimation of confidence while continuing to involve the Competent PersonÆs experience in the process. Methods for quantifying confidence in mineral resource estimates for advanced projects and operating mines have also been developed.Classification is undertaken primarily as a communication tool between the estimators and the other stakeholders in the process. A brief examination of the stakeholdersÆ requirements is included.

Sep 26, 2011

By D. F. Malan

This paper provides an overview of the concepts of citations and journal impact factors, and the implications of these metrics for the Journal of the Southern African Institute of Mining and Metallurgy (JSAIMM). Two key research literature databases publish journal impact factors; namely, Web of Science and Scopus. Different equations are used to calculate journal impact factors and care should be exercised when comparing different journals. The JSAIMM has a low impact factor compared with some of the more prestigious journals. It nevertheless compares well with journals serving other mining sectors, such as the Canadian CIM Journal. The problems associated with journal impact factors are discussed. These include questionable editorial practices, the negative impact of this concept on good research, and the problem of a few highly cited papers distorting the journal impact factor. As a consequence, there is growing resistance to the use of journal impact factors to measure research excellence. The San Francisco Declaration on Research Assessment is a global movement striving for an alternative assessment of research quality. As a recommendation, the Editorial Board of the JSAIMM should adopt a pragmatic approach and not alter good journal policies simply to increase the journal impact factor. The focus should remain on publishing excellent quality papers. Marketing of the Journal, the quality of the published papers, and its open access policy should be used to counter the perception that journals with high impact factors are better options in which to publish good research material.

Sep 1, 2022