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By Charles H. White

METHODS in colorimetry are based on the assumption that the intensity of the color of a definite volume of solution is directly proportional to the quantity of the color-producing substance' present. In the preparation and examination of colored solutions there are three ways in which the depth of color may be varied. These variables are; (1) the quantity of the coloring matter, (2) the quantity of the solvent, or the dilution, and (3) the thickness or depth of that portion of the solution examined. With these three variables as a basis, three general methods in colorimetry have been devised, all of which have been used in the determination of carbon in steel. In the first method, the quantity of the solution is kept the same for both the unknown steel and the standard, and the sections compared are of equal thickness, while the quantity of the standard is varied until the color obtained is of the same intensity as that produced by a definite quantity of the unknown steel. In laboratories where this method is used there is pre¬pared and kept for permanent use a series of solutions with varying amounts of the standard, representing the percentages of carbon from the lowest to the highest demanded in that laboratory. These standard solutions are kept in bottles, or test-tubes of equal diameter, and are arranged in series from the faintest to the most intense color, so that it is a simple matter to find the place of the unknown steel in the series, when the solution is of a definite volume and is contained in a tube of the same diameter as the standard tubes. In the second method, equal quantities of the standard and of the unknown steel are dissolved, the standard is diluted to a definite volume, and the solution of the unknown steel is di-

Sep 1, 1906

By J Coombes

There is much debate on the Competent Persons qualifying criteria for providing classified resource estimates for public reporting. The CRIRSCO family of codes including the JORC Code, SAMREC, PERC and NI43–101, require Competent Persons to have at least five years ‘relevant’ experience and belong to professional bodies. These codes provide further, albeit vague, guidelines to assist individuals with their personal decision to take on the mantle of ‘Competent Person’. There is a risk, however, that these qualifying criteria can result in ill-prepared Competent Persons whose actions and recommendations would undermine their own reputation and that of the organisations that employ them; the integrity of the profession and the principles based reporting systems; as well as the stability of stock markets that rely on these estimates.Based on doctoral study on the development of professional competency within the mining industry, this paper presents an evaluation of the suitability of the current qualifying criteria as well as an analysis of alternative criteria. The research included a series of interviews with industry experts and an online survey of resource geologists. Semi-structured interviews provided a sense of experts’ expectations and interpretation of the current definition of ‘Competent Person’. The comprehensive online survey included a self-assessment, a series of situational questions designed to evaluate responses to typical resource geology scenarios and a set of open-ended questions relating to factors contributing to competency development.A summary of the data analysis, interpretation of the results and a set of recommendations for revised ‘Competent Person’ qualifying criteria are presented. This paper contributes to the conversation on what makes a person suitably qualified to report classified resource estimates and provides practical targets that can be used in the professional development of resource geologists.CITATION:Coombes, J, 2014. Redefining Competent Persons criteria for resource geologists, in Proceedings Ninth International Mining Geology Conference 2014 , pp 153–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By M. Neises, M. Roeb, C. Sattler, S. Stenger

"A two-step thermo-chemical cycle process has been developed and investigated. It is based on metal oxide redox pair systems, which can split carbon dioxide as well as water molecules by extracting oxygen atoms and reversibly incorporating them into their lattice. If concentrated solar radiation is used as the heat source, a promising method exists to produce synthesis gas from water and CO2. An easy way of operation is gained by the combination of a ceramic substrate as the absorber structure, which can be heated to high temperatures with concentrated solar radiation, and of a metal oxide coating which is capable to carry out the redox reactions. The performance and kinetics of a ferrite based redox material coated on ceramic substrates were investigated in a laboratory set-up. CO2 could be reduced with significant conversions. In addition, several side reactions were observed like the formation of carbon and like the Boudouard reaction.IntroductionThe search for alternative energy carriers and for processes able to reuse carbon dioxide stimulates the research for sustainable routes of alternative fuel production. In the scope of this search thermo-chemical processes combined with sources of concentrated solar energy have become more and more attractive. Ideally, the only raw materials for such processes are water (H2O) and carbon dioxide (CO2) enabling not only a process free of emissions, but also allow to reduce emissions of other processes by reusing CO2 to provide synthesis gas, which itself can be applied to produce chemical commodities or even better synthetic fuels like methanol or petrol.In contrast to the direct splitting of those raw materials, thermochemical cycles split water and CO2 in several steps and enable hydrogen (H2) and carbon monoxide (CO) generation at temperatures controllable by today’s technical equipment. One of the most interesting thermochemical cycles is a two-step process using metal oxide based redox systems. During the first step of this cycle (the regeneration step) the metal oxide is reduced setting some of its lattice oxygen free according to reaction (1). In the next step (the splitting) the reduced and activated material is oxidised by withdrawing oxygen from water and CO2 and at the same time hydrogen and CO is set free according to reactions (2a) and (2b) respectively."

Jan 1, 2011

By J. R. Knudson

A major contribution to the art of blasting was made at the Cleveland- Cliffs Iron Company?s Hawkins Mine in Cashwauk, Minnesota during April of 1956. It was here that the first experiments with fertilizer grade ammonium nitrate were conducted-experiments which led to the development of the ammonium nitrate and fuel oil method of blasting which has been eagerly adopted by open pit and quarry operators throughout the United States. While this new blasting agent was a more or less natural outgrowth of the Akremite Process devised by Maumee Colleries of Terre Haute, Indiana; no one, to our knowledge, had used this particular combination of ingredients prior to this time. Certainly this was a "break-through" as far as the Lake Superior District was concerned. Akremite consists of a mechanical mixture of grained ammonium nitrate and a solid carbonaceous material packed in a plastic bag. At the time of its introduction to the Mesaba Range, Akremite sold for 10.5 cents a pound as compared to the 18 cent powder previously used in both wet and dry large hole blasting. The discovery of this agent was indeed a remarkable achievement, one that afforded a substantial reduction in blasting costs. However, Akremite proved to be only an intermediate step in the evolution of our present low cost explosives. Cleveland-Cliffs utilized prilled ammonium nitrate and fuel oil and then eliminated the mixing and packaging plant entirely by combining the two raw materials in the field at the drill hole collar or in the hole itself. Thus we have approached the ultimate in simplicity, for the blaster and his helper now manufacture their own explosives not only as they are needed but where they are needed, and at a cost of under 4 cents a pound. This two-man crew may charge and explode as much as 8 tons of ammonium nitrate in an eight-hour shift and in so doing break some 65,000 tons of ore.

Jan 1, 1959

By R. E. Mitchell

The environmental impact assessment (EIA) is the accepted method for evaluating proposed mining and other industrial projects to obtain regulatory approval and to help companies plan for responsible development. Another increasingly common evaluation system for proposed projects is the environmental, social and health impact assessment (ESHIA). An ESHIA differs from an EIA for its generally more comprehensive and inclusive approach to evaluating potential impacts, such as on public health, and other features such as an ecosystem services approach to assessing biophysical and community impacts. An ESHIA may also be required by certain lenders for financing major projects. In this paper, EIA standards for the province of Alberta, Canada are discussed and compared to ESHIA. It concludes with several recommendations for consideration.

Jan 1, 2012

By A. Tohn, L. May, Adham. K.

The path from process conception to commercial implementation poses significant technical, economic, and sometimes political challenges for every project team. Solving the technical challenges typically distinguishes successful projects from those that fail. Here, the authors provide an outline for technical success based on lessons learned from years of experience in process design and R&D. Challenges faced by new technology developers, with regard to design and definition, are described. Experience-based methods to avoid missteps are shared. Special emphasis is placed on the selection of viable unit operations, definition of known and unknown parameters, experimental screening of options, and piloting for scalable design information. Use of computational models to define, assist, and interpret the pilot operations and results are described. Furthermore, the value of active collaboration amongst the design, research, and owner team is demonstrated.

Jan 1, 2011

By M. R. Rosen

A technique is presented for simple characterization of the performance of flocculents in various mining applications. The method utilizes three key parameters obtained from raw settling data and combines them into a single athematical parameter called the desirability coefficient. The first two parameters are the timesrequired for the slurry-supernatant interface -to fall to two selected fractions of the starting height, and the third is the clarity of the supernatant liquid. The relative values of the three parameters may be assigned different weights in order to make them correspond with laboratory and field performance requirements of a particular industry. Provision is also made of an, internal comparison of test flocculant data with that of a control.

Jan 1, 1980

By Sheldon P. Wimpfen

Forecasting, an ancient art, is con-ducted by everyone in varying degrees. It is a vital aspect of mineral production and conditions must be predicted over a long time frame in all aspects of the industry from exploration to plant construction. Although many government agencies as well as private industry make forecasts, there are insufficent "make good" analyses performed. The performance of more such studies could sharpen forecasting ability.

Jan 1, 1983

To generate a most profitable ultimate pit limit is generally the first step in mine design. This paper presents a new graph theory oriented, optimum ultimate pit limit design algorithm which will maximize the total undiscounted net profit. This algorithm performs much better than the well known Lerchs-Grossmann algorithm, in terms of the reduction in computation time and computer memory requirements. This algorithm operates on many directed trees in a graph, where each vertex in a tree represents a block in the mine model. The formation of each directed tree is based more on the ore-waste support concept than the geometry constraints alone. The general procedures of the algorithm, programming considerations and two case study results are discussed in the paper.

Jan 1, 1990

By S. L. Ducummon

Inactive underground mines now provide essential habitat for more than half of North America's 44 bat species, including some of the largest remaining populations. Thousands of abandoned mines have already been closed or are slated for safety closures, and many are destroyed during renewed mining in historic districts. The available evidence suggests that millions of bats have already been lost due to these closures. Bats are primary predators of night-flying insects that cost American farmers and foresters billions of dollars annually, therefore, threats to bat survival are cause for serious concern. Fortunately, mine closure methods exist that protect both bats and humans. Bat Conservation International (BCI) and the USDI-Bureau of Land Management founded the North American Bats and Mines Project to provide national leadership and coordination to minimize the loss of mine-roosting bats. This partnership has involved federal and state mine-land and wildlife managers and the mining industry. BCI has trained hundreds of mine-land and wildlife managers nationwide in mine assessment techniques for bats and bat-compatible closure methods, published technical information on bats and mine-land management, presented papers on bats and mines at national mining and wildlife conferences, and collaborated with numerous federal, state, and private partners to protect some of the most important mine-roosting bat populations. Our new mining industry initiative, Mining for Habitat, is designed to develop bat habitat conservation and enhancement plans for active mining operations. It includes the creation of cost-effective artificial underground bat roosts using surplus mining materials such as old mine-truck tires and culverts buried beneath waste rock.

Jan 1, 1997

By O. J. Malacarne

The use of a series of thickeners for-washing of the slime fraction of a leached ore is not uncommon in the uranium industry; however, few ore processing mills have used a thickener circuit for washing leached total ore. The, common, practice is to wash the sand fraction in classifiers and, the slime fraction only in thickeners. At the Uravan mill of Union Carbide Nuclear, Company, a total ore' acid leach is employed to extract uranium values from sandstone ores. These leached ores are then washed at a nominal rate of from 1,000 to 1,300 tons per day in a series of washing thickeners. A typical screen. analysis of the ore being washed in these thickeners, is 25 percent -200 mesh, 3 percent +35 mesh and about, one' percent +l4 mesh., The amount of slimes (-200 mesh) will vary from 20 to 30 percent s the mill receives ore from 150 different mines The washing liquor is acidic, from a pH of about 2 in the first thickener to 0.6 pH in the last thickener and of course ally acid duty equipment must be used. The Uravan mill of Union Carbide Nuclear Company is located in Montrose County, Colorado and is physically located on a canyon wall along the San Miguel river. The thickeners referred to in this, paper are located on top of the mesa above the canyon. For purposes of identification, these thickeners are numbered 1 through 8 from south to north.

Jan 1, 1962

By Paul Hughes

This paper describes a focus of work presently being conducted at the Rock Mechanics Research Group at the University of British Columbia. The underhand method under consolidated fill ensures a high recovery under an engineered back that is comprised of cemented rock fill and/or cemented paste fill. This method of mining has been employed successfully in mines throughout North America as a method of mitigating exposure to the operator having to work under a seismically active ?back?. This paper reviews design methodology in the placement and analysis of sill mats with reference to site observation coupled with on going numerical and analytically derived solutions.

Jan 1, 2006

By W. P. Campbell

THE investigation herein described had its beginning in the chemical laboratory of the Department of the Interior, Calgary. After the transfer of the natural resources to the Province of Alberta in 1930, the laboratory was closed and the investigation discontinued, but in 1933, with the permission of the Director of the Mines Branch, the work was again taken up and brought to completion. OBJECT OF THE INVESTIGATION The object of the investigation as originally planned may be stated as follows : (1) To determine the chemical composition of the limestone formation underlying Turner Valley gas field. (2) To identify 'beds' in the limestone, if such existed, with definitecharacteristics which would mark them from immediately overlying and underlying measures. (3) To relate information acquired on the composition of the limestone to the occurrence of oil and gas in the particular section examined. Definite information was lacking as to the exact chemical composition of the limestone and of its variations in composition at various depths. The formation was generally referred to in the field as the 'dolomitic' limestone, but the depth to which the dolomitized zone extended and the degree to which the limestone generally had become dolomitized were not known. Jn the drilling and logging of wells, the recognition of suitable 'markers' in the various formations is a matter of some importance. Markers are generally relatively small but widespread members of a formation, which have some characteristic property, of colour, composition, or form, by which they may be identified, and with them, consequently, the formation of which they form a part. In the formations above the limestone in Turner Valley, a number of well defined and easily recognized markers are known to geologists, drillers, and others interested in the field. Many of these markers Hand out in sharp contrast to adjoining measures and are therefore easily recognized; in others, the contrast is less sharp, with consequent difficulty in identification.

Jan 1, 1937

By Kazutoshi Haga, Batnasan Altansukh, Shirchinnamjil Nyamdelger, Atsushi Shibayama, Narankhuu Ariunbolor, Gunchin Burmaa

In this study, the authors investigated the capability of an acidic thiourea solution and silicon-organic polymers (PSTM-3c, PSTM-3T) as ion-exchange resins to recover of gold from gold-bearing ore concentrates. Firstly, elemental gold present in flotation concentrates was dissolved by leaching with a solution of nitric acid and thiourea under the optimized conditions. The best result on gold thiourea leaching was obtained under a nitric acid concentration of 2 N, thiourea concentration of 2 %, and oxidant (Fe2(SO4)3) concentration of 3 %, solid:liquid ratio (S:L) of 1:20, leaching time of 6 hours at 20 °C with a gold recovery of 93.7 % for a gold flotation (unroasted) concentrate. For the roasted gold concentrate, the dissolution of gold was 94.8% under the optimized leaching condition as nitric acid concentration of 0.5 N, thiourea concentration of 2 %, and the oxidant concentration of 1 %, S:L ratio of 1:10, leaching time of 4 hours at 50 °C. Secondly, a series of sorption tests was carried out on a pregnant leach solution containing gold complex Au[S=C(NH2)2]2+ using silicon-organic polymers (PSTM-3c and PSTM-3T), respectively. The effects of solution pH, adsorption time and temperature in the sorption process are also studied. As the results, the PSTM-3c and PSTM-3T polymers were adsorbed about 94.4 % and 95.1 % gold from the pregnant leach solutions under the optimum sorption conditions, respectively. It was found that the both PSTM-3c and PSTM-3T polymers were effective for the recovery of gold from the pregnant leach solution of thiourea. Adsorption activity of the PSTM-3c and PSTM-3T polymers was confirmed by new peaks near 1700 cm-1 in the FT-IR spectrum of the gold-adsorbed polymers, respectively.

Jan 1, 2014

By Jamal Rostami

With the recent technological advances; Tunnel Boring Machines (TBM) have become a viable economic alternative to drill and blast in hard rock excavation. These machines are finding increasing use in underground mine development due to the potential benefits they offer. The successful application of TBM technology to mining depends on the selection of the most suitable equipment and cutting tools for the rock and ground conditions to be encountered. In addition to required testing and geotechnical investigations, cutterhead design optimization is an integral part of the machine selection to assure a successful application of the machines in a specific project. This paper presents and discusses the back-ground of TBM application in a mining environment and the lessons learned, the process of conducting site investigation and the necessary laboratory testing together with machine selection and performance estimation for TBM use III mine development.

Jan 1, 1997

By A Melkumyan, M Balamurali

Geological domains describe the mineralisation state and stratigraphic location of different geological regions of mines. They play a very important role at the geological modelling stage as weight percentage of chemical elements information within each geological domain is assumed to be correlated while information coming from different geological domains is considered uncorrelated. Having correct domain assignments to both the chemical assays and the 3D space of modelling is critical for building a reliable geological model of the mine.As standard practice significant effort is invested into the interpretation of the deposit and identification of the geological domains for the chemical assays and the 3D geological space. Despite these efforts, there are some chemical assays with ambiguous geological domain where the exploration assay domain and the block domain do not match. Incorrectly including a sample in the wrong domain can cause a large change in the predicted weight percentage of chemical elements estimation for that block. Therefore, the major challenge of grouping the spatially correlating weight percentage of chemical elements is how to determine which of these domains best fits these misclassified samples.This work proposes machine learning based autonomous technique for identifying to which geological domain (the exploration assay domain or the block domain) the misclassified sample belongs. The proposed methodology is based on Gaussian Process (GP) classification. The GP machine learning approach consists of training and inference stages. At the training stage the GP automatically learns the properties of different geological domains using the chemical assays with unambiguous domain assignment. Then, at the inference stage the GP makes predictions for the geological domains of the assays with ambiguous initial domain assignment.We tested the proposed technique by conducting a case study for an iron ore deposit located in Western Australia. The results demonstrate that the application of the proposed GP technique removes statistically significant deviations in the assay values in many regions: mineralised ore region, unmineralised region, highly weathered region and intrusive material that is highly variable. In this case study the proposed methodology autonomously identified the geological domains for more than 50 per cent of samples which are initially ambiguously classified. For the majority of the assays the GP predicted domain agrees with the geological domain assigned by the exploration assay.CITATION:Balamurali, M and Melkumyan, A, 2014. Automated identification of geological domains for exploration assays with ambiguous initial domain assignment in an iron ore deposit, in Proceedings Ninth International Mining Geology Conference 2014 , pp 99–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By K. J. G Hedges

"Once a health based guidance limits for exposure to diesel exhaust have been established, and as part of a multi-disciplinary team, the program for exposure reduction should incorporate the plan-do-check-adjust cycle. Setting a suitably protective (health based) occupational exposure limit (OEL) for diesel particulate matter (DPM) and nitrogen dioxide is a key driver to reduce exposure. It is important to go beyond regulations and reduce exposure to diesel exhaust, DPM, as low as reasonably achievable (ALARA) such as that prescribed under the Australia, Queensland Mining and Quarrying Safety and Health Regulation 2017 where under section 135 Limiting workers exposure, the workers exposure must not exceed the exposure limit applying to the worker for the hazard; and is ALARA. It appears that previously acceptable OELs are no longer safe. Therefore it is important that the internal responsibility system be implemented and the precautionary principle approach be followed, especially as it may be some time before a suitably protective OEL specifically for DPM is in place. One leading multi-national mining company BHP Billiton has acknowledged a significant lag that exists between regulatory action and the level of science that informs health risk. This company is managing exposure to diesel exhaust to as low as technically feasible. This same company that has set an interim target for managing diesel exhaust to 0.03 mg/m3 is achieving these levels which paves the way for other mining companies and general industry including construction. The Occupational Cancer Research Centre 2017 recommends reducing personal exposure to within 0.02 mg/m3 (EC) for underground mining and 0.005 mg/m3 for other workplaces. Controlling DPM is important to prevent cancer however it is also important that that nitrogen dioxide (NO2) be reduced (ALARA) and that careful selection of control technology be considered such as the proper selection of a diesel oxidation catalyst so that the level of NO2 does not in fact increase. The example from BHP Billiton provides a leading practice including using a multi-disciplinary approach and the importance of controlling emission at source and having an auditable diesel emissions based monitoring program in place."

Jan 1, 2019

By E. J. Onuscheck

With passage of the Federal coal' Mine Health and Safety Act of 1969, many challenges have been directed to the industry's mining and safety engineers. The most critical challenge is that of ventilation. The language concerning ventilation in many sections of the Act could very well deprive or limit the mining engineer in planning the ventilation for new mines, since the Act requires federal approval of all ventilation plans. Dependent upon approval and of course application of the law, this could, due to economics, prohibit the opening of new mines in some cases. Petitions for modification of some mandatory standards relating to ventilation have already been filed under Section 301(c). It is quite possible that many of these standards may be modified.

Jan 1, 1970

By L. Juteau

"""The north coast of the St. Lawrence River will be the scene of an industrial development during the coming decades"". The facts which underlie this statement are the occurrences of iron and titanium ore, the abundance of hydro-power and the availability of deep-water ports in this region. Havre St-Pierre, Sept-Iles, Port Cartier and Baie Corneau already exist as major ports and urban centers. The huge quartz deposit at Baie Comeau will be a decisive contributing factor in the development of a metallurgical plant in this area. Due to its purity, it lends itself, first of all, to the manufacture of glass of different kinds, being comparable to the quartz sands now used by the plate glass and glass container industries in the Montreal area, Moncton, N.B., Trois-Rivieres and - in the future - at Bécancour, Quebec. However, its high quality will also make it possible to use it as one of the main basic materials for the production of silicon carbide and ferrosilicon, and as a flux in metallurgical processes. It is intended, in this report, to offer conclusive proof of the economical importance of this large quartz deposit by presenting the results of the studies made to date."

Jan 1, 1971

By M. Nambiar

Due to the remote locations of the mining projects and the demand for long transmission lines to provide electrical power, mining sites often operate with poor network power quality and low short circuit capacity. In order to cope up with this situation, more and more mining projects are considering the installation of appropriately designed Synchronous Condensers(SC) together with Power Factor Correction and Harmonic Filter System(PFC&HFS). The installation of these power quality equipments is viewed as a technological advancement in the mining application. An adequate level of short circuit power is essential and has to be ensured for the safe and reliable operation of especially large cycloconverter driven gearless mill drive systems used for grinding application. Increase in plant short circuit power is generally achieved by lowering the impedance of the supplying network. The SC also provides smooth voltage control during mill starting or major load trips, thereby regulating the plant voltage within the required limits. This paper will explore the impact, technical advantage and reasoning for the selection of the advanced hybrid technology mentioned above, in order to cope with the power system challenges for future mining projects. It also highlights the potential problems and how to address them carefully.

Feb 23, 2014