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By Marcela Gotelip Barbosa

Pellets are the main iron input to the blast furnace at ArcelorMittal Lazaro Cardenas iron and steel making facility in Mexico. Pellets are made at this facility using the concentrates generated and shipped from their captive mines viz., Las Truchas, Pena Colorada, Volcan Sonora. The concentrating plants, after grinding the ore to the liberation size, use magnetic separation and flotation to reject the silica, sulphur and phosphorous impurities. At Volcan Sonora Mines, the ore is contaminated with phosphorous minerals, and hence, after magnetic separation, the phosphate minerals are floated using anionic carboxylate collector (sodium oleate). Apart from floating the phosphate minerals, the sodium oleate also has some tendency to smear on the iron bearing mineral surfaces leaving a hydrophobic surface, which is expected to reduce the green pellet strength due to absorption of ultrafine sized air bubbles on these surfaces, and further generate higher levels of dust during the induration process. In order to alleviate this industrial problem, comparative studies were carried out on the concentrates from magnetic separation using reagents from synthetic sarcosinate and carboxylate family collectors. Results have indicated that the sarcosinate family members not only were found as replacement to carboxylate collectors, but also reduce the phosphorous content below the values achieved with oleate, thus have considerable benefits in the downstream steel making process. Based on the results, plant runs are being taken up at Volcan Sonora. In this article, the laboratory results obtained on iron grades and recoveries, and phosphorous rejection using both the reagents are presented.

Aug 1, 2018

By Jerry G. Rose

This paper addresses a process by which both the disposal and utilization of preparation plant coal refuse can be simultaneously accomplished with an attendant benefit of significantly increasing the percentage of extractable coal. A laboratory study is described in which coal refuse was successfully utilized as an aggregate in low cost concrete (coal-crete) mixes under simulated mine environments. Coal-crete specimens with compressive strengths of 14,000 kPa (2,000 psi) were consistently produced. A construction sequence and mining plans are offered for placing the low-cost coal-crete pillars in accessible areas in room-and-pillar mines so that a Substantial portion of the remaining coal pillars could be extracted. The method could be applicable in areas where mining procedures do not permit pillar extraction because of possible surface subsidence, roof problems, or other conditions. Possible structural difficulties with the coal-crete pillar support system are discussed. Using a discounted cash flow analysis, the economic feasibility of mining with the coal-crete pillar system is investigated. The cost of the coal-crete pillar system is compared to the cost of a mining system which would have less coal recovery. The analysis indicates that although at higher coal selling prices the coal-crete mining system may yield an acceptable rate of return, the alternative of leaving the coal pillars is more attractive at the present time.

Jan 1, 1977

By Oliver Bowles

The exingencies of a world war have brought home to the American public, especially the people of the. Eastern States, the urgent need for conserving fuel. Transportation problems in the East have created an unprecedented situation wherein fuel-oil supplies are greatly restricted, and the consequent increase in demand for coal further complicates the problem of transporting and storing that commodity. People should awaken to the need for utilizing every possibly means of conserving to fuel, even to the extent of reducing the temperature in their homes.

Jan 1, 1942

By D. A. Paice

A power supply to operate fluorescent or mercury vapor lamps from 300 volt dc coal mine trolley wires has been developed for the Bureau of Mines. A high frequency regulated inverter unit incorporates ballasts for a mix of lamp loads up to 650 watts. For 600 volt trolley systems an additional power converter unit was developed to step down the dc voltage to 300 volts for the inverter unit. Both units have operated in a working coal mine for over 12 months without need for servicing. The lamp load in these tests included two 100 watt mercury vapor head lamps and six 75 watt fluorescent lamps.

Jan 1, 1979

By Thiago Félix dos Santos

A maioria dos materiais poliméricos sintéticos apresentam superfícies quimicamente inertes, isentas de porosidade e baixa energia de superfície. Este trabalho tem como objetivo realizar a modificação superficial do substrato têxtil de forma a aumentar a sua molhabilidade. Os tecidos de poliéster são hidrofóbicos e, por isso são desconfortáveis aos usuários, pois a fibra não absorve o suor do corpo, outro fator que é prejudicado pela hidrofobicidade da fibra de poliéster é o tingimento das mesmas. Portanto, tratamentos superficiais vêm sendo utilizados para minimizar esse problema e o plasma é uma técnica que se mostra bastante eficaz. O plasma ao interagir com a superfície do substrato provoca alterações químicas e físicas melhorando suas propriedades. Portanto, através do plasma é possível alterar as propriedades físico-químicas das superfícies de tecidos de poliéster, tendo como resultado o aumento da hidrofilidade dos mesmos com o incremento de grupos funcionais polares e o aumento da rugosidade em sua superfície. As amostras foram tratadas em um reator de plasma de barreira dielétrica a pressão atmosférica, em diferentes tempos de tratamento e voltagem. Após as funcionalizações as amostras foram submetidas ao teste de capilaridade, a fim de observar a melhora na hidrofilidade. Todas as amostras tratadas tiveram aumento na molhabilidade, com exceção, as amostras tratadas com 10 kV, onde não houve alteração.

Aug 7, 2018

By David Garry, Michael J. Brnich, Lynn L. Rethi, Henry P. Cole, William J. Wiehagen, Roberta A. Calhoun

This document contains most of the materials needed to use the exercise. The main part of the document is the instructor's copy. It tells how to use the exercise, presents the objectives, the master answer sheet, the scoring key, and discussion notes to be used following the exercise. The next section summarizes results from field tests of the exercise, and reports the miners' evaluation of the activity. The last part of this document is three appendices. Appendix A is the exercise problem booklet. This booklet can be duplicated locally. The booklets are reusable. One is needed for every person in the classroom. Appendix B is the answer sheet and the trainee's questionnaire. Copies of this answer sheet must have the latent image (invisible) ink answers that appear in Appendix C printed on them.1 Answer sheets are consumable. One is needed for each person or each small group of persons who work the exercise. Exercise Summary Read this section first. It determines if the exercise is appropriate for your classes. If you choose to use the exercise, examine the table of contents and review the remainder of this document. Type: Latent image Audience: Supervisors, Safety Personnel and Accident Investigators Length: Eight questions (30 minutes for administration plus 30 for discussion) Skills: Developing a strategy or plan to prevent slips and falls Following correct procedures in conducting an accident investigation Preventing unsafe work practices Recognizing and instituting hazard controls in the section Identifying and implementing safe work procedures Location: Underground coal mine section Problem: You have been the general mine foreman at White Rock Mine for 4 years and have worked at this mine for 12 years. The mine superintendent calls you into his office. He gives you an accident report of an employee in 4-G section who was injured while carrying rock dust bags from the rock dust car to a battery powered scoop. It is several days after the accident and the mine superintendent assigns you and the safety supervisor to thoroughly investigate the accident to determine all the contributing factors. Your job is to make specific recommendations to prevent future slipping/tripping accidents.

Jan 10, 1999

By Mark S. Rayson, Jessy Lee, David O. Johnson, Matthew R. Rawls

The ability to manipulate the structure of liquid chemicals in an explosive is important in mining applications, where precision blasting is crucial for the safe, reliable, economical and eco-friendly extraction of ores. Static mixers allow explosives, emulsion-based in particular, to be custom-made as they offer precise and reproducible mixing without the need for moving mechanical parts. In this paper, we perform numerical simulations on the laminar mixing of two nitrate-based fluids in a Kenics static mixer unit for various mixer parameters. Two numerical methods were investigated in the study of the mixing pattern: solving the mass transfer equation and using particle tracking. The former introduces artificial numerical diffusion which can lead to spurious smearing of the component boundaries, a problem that can be avoided with the latter technique. We have also demonstrated that the particle tracing method is capable of qualitatively predicting the blending patterns under the conditions studied.

Jan 1, 2014

By G. W. Poling

Chemical and physical properties of thiol collectors are re-examined to compare the prospects,of heavy metal-thiolate or disulphide surface reaction products acting as actual collector species. Recent evidences for the existence and importance of each of these types of adsorbed species on sulphide minerals are also discussed. A conclusion is reached that partial coverage by chemisorbed heavy metal thiolate is often sufficient to confer practical levels of hydrophobicity and floatability. Only on a few highly conducting and "noble" sulphides does adsorbed disulphide-type collector oxidation product appear to be significant.

Jan 1, 1976

By Mitchell D

In recent years the need to provide increased ventilation to improve environmental conditions rather than to dilute firedamp has led to increasing interest in the use of recirculation. Present UK mining law prohibits recirculation in ventilation, but it has been permitted selectively by exemption granted by Hm Inspectorate of Mines and Quarries. The conditions of use imposed by these exemptions to safeguard the safety and health of miners are examined in detail, dealing separately with primary and auxiliary recirculation systems.

Jan 1, 1988

By DAVID C LAURENCE

The richer, shallower sapphire deposits of the New England region of New South Wales which have been traditionally mined by the small miner are almost worked out. Larger mining and exploration companies are replacing the small miner and exploring for the primary source of sapphire or lower grade alluvial deposits.Although in recent years considerable exploration effort has been directed at locating the primary source, commercial exploitation of sapphire is still restricted to the working of alluvial deposits.If the Australian industry is to compete against Asian and African producers it must use cost effective exploration, mining, processing and marketing methods.

Jan 1, 1990

By T. B. M. Himawan

In this study, effect of thiosulphate and oxidation using oxygen were studied in arseno copper ore flotation. Single mineral study of chalcopyrite and tennantite in regard to the aforementioned techniques was also studied. Zeta potential, XPS, contact angle and floatability of single minerals were conducted for each treatment to understand the mechanism. It was revealed that the separation is best conducted in alkaline condition at where there will be interaction between thiosulphate and the mineral surface as well as the formation of hydroxide species in the oxidation using oxygen. From zeta potential of both thiosulphate and oxidation conditioning, it can be found that the reactivity of tennantite is much higher rather than chalcopyrite resulting higher rate of depression on both techniques as shown from contact angle and floatability of each mineral after treatment. XPS spectra confirmed qualitatively and quantitatively the existence of species responsible for the depression of each conditioning techniques. As for the copper ore flotation test, it is the oxidation using oxygen provides best performance after 60 minutes of oxidation. Keywords: tennantite, chalcopyrite, arseno copper ore A, thiosulphate, oxidation using oxygen

Sep 1, 2012

CHALLENGES TO SCHEDULE/BUDGET Shortage of people (contractors, vendor support, engineering, staff) 2007 projects off the shelf Increase in metals prices Shortage of large tires Reserve increase Size of mine Unskilled labor force Community/government relations Limited access into valley English to Spanish SOLUTION Line 1 Line 2 concurrent construction, EPCM engineering review, advance scheduling Placed line 2 orders earlier Hedged currency, bulk orders Strategic alliances Flexible design Plan Deliveries Training, multiple contractors Engagement Built/upgraded roads Technical translators

May 1, 2010

By Thornton D, Firth B, Kojovic T, Brien G, O&apos

Coal fragmentation is a function of coal type and mining process. Each unit step in the mining, handling and crushing chain of coal imparts energy to the material and impacts on size degradation and consequent mineral matter liberation and pla

Jan 1, 1998

By Theodore Marvin

NOW that real progress is being made in building airplanes that can stand up under adverse conditions in isolated parts of the world, utilization of aviation by mining and petroleum companies is proceeding rapidly. This isolation, offering such handicaps to ordinary methods of transportation, also was the thorn in the flesh of aviation until the recent advances in plane and englue design. The accompanying illustration shows one of the six new planes just delivered to the U. S. Government for map making. The planes will be used in Department of Commerce, Coast and Geodetic Survey, Navy Hydrographic, and Insular work. There is a trap door in the bottom of the hull for a Fairchild camera which takes five pictures-vertical, N60°, E60°, S60°, and W60°-at regular intervals. It is manufactured by the Grumman Aircraft Engineering Corp., Farmingdale, N. Y.

Jan 1, 1935

By Liming Yuan, Wei Tang, RICHARD THOMAS, JOHN SOLES, DAVOOD BAHRAMI

The abstract discusses the issue of mine equipment fires caused by hot surface ignition of flammable liquids. The research investigates the ignition probability of liquid fuels (diesel, engine oil, hydraulic fluid) on different metal surfaces (stainless steel, cast iron, carbon steel) under various ventilation speeds. The results show that the type of metal and ventilation speed influence the ignition temperature, with diesel being the most easily ignited fuel and carbon steel requiring a higher ignition temperature. The study provides data for understanding equipment mine fires and developing mitigation strategies.

May 4, 2022

By C. J. Edmonds, R. Bland, W. C. Ferguson, R. Whitehead

"In 1969, the Environmental Science Division of James F. MacLaren Limited received authorization from The International Nickel Company of Canada, Limited to carry out a water quality monitoring program in the Lake Shebandowan region of Ontario, where a new base metal mining and milling complex was expected to go into operation in 1972. The objective of the program is to establish base-line water quality characteristics. Fully realizing their corporate responsibility to minimize the effects of the proposed activities on the environment, Inco decided that it would be desirable to establish a program by which any change in the quality of environmental waters will be detected before detrimental conditions ensue, permitting prompt corrective measures to be taken. The program has been in progress for over two years. The waters are sampled and analyzed four to six times per year. Sampling stations are located in Lake Shebandowan and on the adjacent Gold Creek - Matawin River system. On-site analyses and measurements are made of flow, dissolved oxygen, temperature and pH. Samples also are collected for later analysis in the laboratory. These samples are analyzed for a wide range of chemical and biological characteristics. The paper discusses the extent of the sampling program, the techniques utilized and the value of such programs in maintaining the quality of the environment."

Jan 1, 1973

By A. Chagnes

This paper presents a modelling tool that can be used to predict the behaviour of solvent extraction processes. In particular, this model allows calculating metal extraction efficiency as a function of pH, solvent flowrate, stripping flowrate and aqueous feed flowrate in the mixers-settlers. This model is applied to the recovery of cobalt from acidic chloride media by using CYANEX® 272 as extractant diluted in kerosene. Keywords: Cobalt, mixer-settler, modelling, solvent extraction

Jan 1, 2020

By Johnson N. W, Quast K. B

Over the years there have been occasional references in the literature to the activating effect of cyanide in galena flotation with xanthates. These have usually been associated with the processing of lead-zinc or copper-lead-zinc ores. Bubble contact curves for the pure galena-xanthate system show a flotation edge at pH 10.4 independent of sodium cyanide concentration which was thought due to hydroxyl ion, not cyanide ion.Flotation tests were conducted on samples of Mount Isa lead-zinc ore using varying concentrations of sodium ethyl xanthate and sodium cyanide. At low collector concentrations, galena recovery kinetics improved with sodium cyanide addition, and the higher the cyanide concentration, the higher the galena recovery rate. At higher collector concentrations, galena recovery rate was independent of sodium cyanide addition.For a given collector addition, the lead grade-recovery curve shifted to an improved position with increasing sodium cyanide level. For the same recovery there was an increase in the lead grade with increased sodium cyanide addition, and this increase was most dramatic at high sodium cyanide concentrations.The presence of sodium cyanide during the grinding of Mount Isa ore caused surface passivation of the iron sulphides and possibly the sphalerite.These sulphides, therefore, reacted with less of the oxygen present in the pulp, hence more oxygen was directed to the surface of the galena. This resulted in an enhancement in the total amount of xanthate adsorbed on the galena that is reflected in the improved flotation response of that mineral.

Jan 1, 1990

By D J. Logan, J Jackson

"As of 1 December 2014, the 2012 edition of the JORC Code requires Ore Reserves to be defined by studies at the pre-feasibility or feasibility level. This paper examines how the pathway for most mining developments is determined in the Pre-Feasibility Study and how a trade-off must be made between the need to make the best decision, the constraints of limited time and resources, and the level of the project’s accuracy and uncertainty in terms of value. Issues considered include framing the scope of the study, planning for robust decision-making and ensuring effective communication between the diverse disciplines within the team.An inherent conflict exists between the immediate value added to a mining business from an increase in ore reserves resulting from a ‘quick’ Pre-Feasibility Study and the long-term value of pursuing a development strategy based on proper investigation and evaluation of the options. Recognition and resolution of this conflict is necessary if a project is to progress into future development stages, both in a timely manner and with the optimal development alternative and strategy.The challenge for project developers and those conducting the Pre-Feasibility Study is to understand what the key deliverables are (ie an Ore Reserve statement, option selection, business evaluation, forward work plan or risks) and how to follow good practice to ensure that these deliver value.CITATION:Logan, D J and Jackson, J, 2016. The pre-feasibility study – big choices, little time, in Proceedings Project Evaluation 2016, pp 122–132 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By Glenn Stevens

After 40 years of operation with the original design, Pan Pacific Copper determined it was necessary to rebuild the Saganoseki Flash Smelting Furnace to continue safe operation. The original design employed a rigid steel frame, which, through hearth growth, led to severe distortion of the frame. Contributing to the continued growth of the hearth were thermal cycles that occurred during the government mandated annual shutdowns. Hatch designed a unique sprung bound, pivoting binding frame to maximize crucible size within the existing furnace footprint, while integrating the PPC designed cooling jackets. The bound system maintains tight brick joints, while the new conductive hearth design with integrated bottom cooling produces a protective freeze layer to accommodate higher furnace throughput. Minimization of furnace downtime for the rebuild was achieved through effective construction planning, highly trained contractors, and through an efficient start-up and ramp-up to full production.