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By K. Peake, A. Dalvi, V. Hernandez, S. Chang, M. Oliazadeh

"Ironstone Resources Ltd. is developing the Clear Hills oolitic iron ore deposit in northwest Alberta, Canada. Sources of oolitic iron ore worldwide are abundant and ubiquitous, but there is currently no commercial technology to extract iron from oolitic iron ores. Mineral processing of the ore to generate a commercial iron ore concentrate is very challenging due to the nature of these ores. Accordingly, Hatch and Ironstone are developing a new pyrometallurgical process (Hatch Ironstone Chloride Segregation) to produce metallic iron from high silica and high phosphorus oolitic iron ores. Following the chloride segregation process, the treated ore is subjected to fine grinding. The iron is then separated by magnetic separation. The iron grade and phosphorus content of the final product shows a strong dependence on the separation methodology and the grind size. The pyrometallurgical process has been developed and tested at a lab-scale pilot plant. The commercialization of this technology could provide an opportunity for the development of a new alternate iron making technology. This paper presents the results of test work done on the raw iron ore to create a concentrate and also on the products of the pyrometallurgical process for the production of a high grade 90% metallic iron product.INTRODUCTION Oolite is a sedimentary rock formed from ooids – spherical particles with concentric layers. There are a number of large oolitic iron deposits where the mineralogical form features a low iron content and high concentration of impurities making them presently impossible to exploit on either a technical or economic basis. The fifteen largest oolitic iron ore deposits in the world are estimated to contain approximately 337 billion tonnes of iron ore, which would be a significant source of supply for worldwide steel production. A viable process that can economically recover iron from these oolitic iron ore deposits could become an important new technology to meet future demand in the steel industry. Hatch and Ironstone have demonstrated that oolitic iron ores can be exploited to produce direct reduced iron (DRI). Direct reduction ironmaking is a method for producing solid metallic iron using different techniques compared to the blast furnace process, which is the more conventional ironmaking route. The demand for the construction of direct reduction ironmaking plants has increased in response to the increasing demand for crude steel. It is viewed as a method of providing low-residual iron sources to scrap-based steelmaking in electric arc furnaces."

Jan 1, 2014

By S. O. Bada

Coal samples taken from the No. 2 Seam and No. 4 Seam in a South African colliery were tested in a rotary triboelectrostatic separator. The two-stage triboelectrostatic separation results using the -177 µm size fraction reduced No. 2 Seam coal containing about 30.4 per cent ash to a clean product of 8.9 per cent and 13.1 per cent ash with combustible recoveries of 9.6 per cent and 30.7 per cent respectively. The same separation approach on No. 4 seam feed coal, which contained 36 per cent ash, produced a clean coal product with 10.8 per cent ash at a combustible recovery of 6.0 per cent. Petrographic tests show a significant improvement in the vitrinite content and a reduction in visible minerals encountered when using the triboelectrostatic separator, with about 53 per cent vitrinite reporting to the clean fraction for No. 2 Seam compared to the feed content of 21 per cent, and a 54 per cent vitrinite in the clean No. 4 Seam from a feed content of 21 per cent. Significant sulphur reductions were also observed after separation in both coal samples, with a better separation in the second-stage coal products.

Jan 1, 2012

By Eleanor Sonley

In October 2000, temporary seismographic stations were installed above the Trail Mountain Mine, Emery County, Utah, USA to supplement a regional network. Over seven months, 1826 mining-induced seismic events were recorded with a magnitude range of M 0 to M 2.2 (Arabasz et al., 2002, 2005). Routine event locations for this dataset cluster around the longwall mining activity during the recording interval. However, applying a double difference relocation technique to the routine locations significantly improves the correlation between mining activity and event location. The resulting relocations depend greatly on station distribution and the number of arrival time picks. We use this dense temporary array to assess station distribution requirements for applying the double difference technique at other mines by systematically removing data from available stations, thus simulating sparser networks. The insight gained using the Trail Mountain dataset is used to develop a metric for assessing the usefulness of above-mine networks and to develop a tool for expanding seismic network coverage. To verify the appropriateness of these tools for wider application, we examine data from two additional mines located in the western United States. Improving the relative locations of mining-induced seismic events highlights the association of these events with active portions of the mine. Clusters, regions of quiescence and relative timing of events can be used by mine operators to assess hazard, optimize production, and evaluate performance of mine plans. The lessons learned from this study may be used in future network design to improve accuracy of event locations at other mines.

Jan 1, 2009

By Jochen Petersen, Diane Taggart

"At an average of 90.3% (for the period of 1 January 2009 to 30 September 2011), Zincor’s zinc recovery was well below the industry standard of 96%. The losses through the residues, in particular the iron residue, were the biggest contributors to the overall zinc loss. It was believed that this loss could be decreased with the implementation of seed recycling. A plant trial was run to test the implementation of a seed recycle. The rate of seed addition through recycle was increased over a 4-week period. The presence of seed decreased the insoluble zinc loss by providing additional surface area for iron to precipitate onto, and reducing coating of unleached neutralising agent. The soluble zinc loss was also decreased at low and moderate seed recycle volumes. The improvement was attributed to agglomeration growth of the recycled particles, which improves the dewatering characteristics of the precipitate. In contrast, the soluble zinc loss increased at high seed recycle rates. This result was attributed to particle crowding and a low wash ratio.INTRODUCTION The Zincor refinery, which closed in December 2011, was situated just outside of Springs in the Gauteng Province of South Africa and employed the conventional Roast-Leach-Electrowin process, which accounts for 75 to 80% of the annual primary zinc production in the world. The refinery fed up to 220 000 t/a of zinc sulphide concentrate. The major portion of the raw material was sourced in Southern Africa from the Rosh Pinah and Black Mountain mines. Between 20 000 and 40 000 t/a of material was imported to make up the deficit and to improve the grade of the feed material. The iron contained in the zinc concentrates, at an average of 6.03% (for the period of 1 January 2009 to 30 September 2011), resulted in the formation of zinc ferrite during roasting, which is insoluble under atmospheric leach conditions. At Zincor, most of the zinc ferrite was dissolved in the residue treatment plant at elevated temperature and high acid strength. The leach liquor from this aggressive leach contained between 15 to 30 g/L of iron, mostly in the ferric form, and was known as the hot iron solution (HIS). The presence of iron in the liquor had an adverse effect on the zinc operation, particularly on the current efficiency in the electrowinning circuit. Therefore the iron needed complete removal."

Jan 1, 2016

By K. N. Santini, J. M. Barker

The perlite industry in the United States continued to undergo rapid change and increased competition last year as it did in 2002. U.S. production in 2004 was 510 kt (562,000 st),an increase following five consecutive years of decline (Table 1). Perlite is exported to Canada and to the Pacific Rim. These partially offset imports. Perlite imports from Greece to the eastern and Gulf Coasts of the United States declined by about 22 percent after reaching a record 240 kt (264,000 st) in 2003.But their market remains protected by high rail rates from western U.S. plants. Minor imports of perlite persist by Termolita from Mexico.

Jan 1, 2005

By L. Malmgren, A. Ansell

This paper deals with the influence from blast induced stress waves on the performance of shotcrete support in the Kiirunavaara mine. Time histories of stress waves from blasting were obtained from measurements during production blasts in the mine, followed by failure mapping. A finite element model, consisting of beam and spring elements, was used to calculate the shotcrete response to vibrations from blasting. The modelling approach was similar to that of a building during an earthquake, with accelerations measured in-situ used as loads. The analysis showed that the calculated adhesive stresses exceeded the strength in the interface between rock and shotcrete near to the blasted ring. It also indicated that tensile rock failure did occur. These types of failure will presumably result in ejection of joint defined rock blocks or rock slabs and will require a ductile support, such as fibre reinforced shotcrete. The predicted failure was confirmed by the mapping, which also showed that the zone of failed shotcrete was much larger in areas with plain shotcrete compared to areas with reinforced shotcrete. L’influence de l’onde de pression générée par les sautages à la mine de fer de Kiruna sur la performance du béton projeté est étudiée dans le présent article. Les ondes créées par les sautages ont été enregistrées et les domages résultants ont été cartographiés. La réponse du béton projeté aux vibrations de sautage est étudiée à l’aide d’un modèle d’éléments finis, constitué de poutres et de ressorts. L’approche est similaire à celle d’un immeuble subissant un tremblement de terre, avec les accélérations internes utilisées comme charges. L’analyse montre qu’à proximité des sautages, la contrainte adhésive dépasse la résistance de l’interface roche-béton. L’analyse confirme aussi l’existence de ruptures en tension. Ces types de rupture induisent probablement l’éjection des blocks définis par les structures du massif rocheux et requierent un support ductil, comme du béton projeté renforcé par exemple. Le type de rupture est confirmé par les observations de terrain, qui montrent aussi une extension plus importante des domages lorsque le béton projeté n’est pas renforcé. In diesem Konferenzbeitrag geht es um den Einfluss, der aus einer Sprengung hervorgerufenen Schwingungswellen auf die Ausführung der Spritzbetonverstärkung in dem Kiirunavaara Bergwerk. Die Aufzeichnungen der Schwingungswellen von Sprengungen gemäß einer Fehlerkartierung beziehen sich auf Messungen, die während der Sprengungen durchgeführt wurden. Ein Finite Elemente Modell, bestehend aus Stab- und Federelementen, wurde für die Berechnung der Spritzbetondeformation in Bezug auf die Schwingungen aus Sprengungen angewendet. Die Modellierungsmethode war ähnlich der eines Gebäudes während eines Erdbebens anhand der gemessenen Beschleunigungen vor Ort, die als Lasten benutzt wurden. Die Untersuchung hat gezeigt, dass die berechnete Haftspannung größer war als die Festigkeit in der Verbindung zwischen Gestein und Spritzbeton in der Nähe des Sprengungscentrums. Die Analyse hat gezeigt, dass die Zugfestigkeit des Gesteins versagte. Diese Arten von Versagen werden als Folge der Herausnahme von Gesteinsbrocken oder Gesteinsplatten erklärt und benötigen eine faserverstärkte Spritzbeton. Das vorausgesagte Versagen bestätigte sich beim Kartieren, welches auch zeigte, dass die Zone des versagenden Spritzbetons in Bereichen mit unverstärktem Spritzbeton viel größer war als in Bereichen mit armierten Spritzbeton.

Jan 1, 2003

By Kwong. Kyei-Sing

Gasification is a process that converts a carbon feedstock into synthesis gas (CO+H2). Slagging gasifiers operate at high temperature and pressure and in a corrosive-wear environment from the slag. Cr2O3-based refractory linings are used to protect the steel vessel that comprises the gasifier from the aggressive gasification environment. Increasing service life of the gasifier is one of the keys for wide spread development of this technology. In support of the goals, research on the gasifier atmosphere, the slag chemistry, the interaction of Cr2O3 refractory with different feedstock mixtures (e.g., coal and petcoke) were characterized by post mortem analysis of bricks from service in gasifiers and thermodynamics simulation of the environment. Examples demonstrating how thermodynamic calculations can explain the post mortem results and make predictions of material interactions will be given. Attention is placed on the possibility of Cr+6 in different feedstock mixtures and operating conditions.

Jan 1, 2010

By Lewis PJ, Halfpenny R, Craighead GA

Exploration drilling by Joint Venture partners CRA Exploration Pty Ltd and Elders Mining PNG Pty Ltd has discovered a signif- icant copper and gold deposit at the Wafi River prospect, 60km WSW of Lae in Papua New Guinea. An indicated resource of 18Mt at 2.5g/t Au using a lg/t cutoff has been delineated in Zone A. No estimate has been determined for the separate copper occurr- ence at Rafferty's Zone but the copper will be significant to the project. Metallurgical studies on the gold indicate that the primary ore is refractory to direct cyanidation giving a highly variable and inadequate response. All conventional refractory ore oxidation techniques perform well on both ore and pyrite concentrate and oxidation occurs rapidly. No metallurgical studies on the copper mineralisation have been undertaken. Hypogene covellite and chalcocite copper mineralisation is associated with an intensely quartz-stockworked, and quartz and alunite-altered intrusive. Economically significant gold mineralisation occurs in distal subhorizontal lenses, within a sedimentary host, that plunge toward the intrusive. These lenses are sandwiched between overlying quartz and alunite-altered zones and underlying quartz and smectite zones in a mixed zone of quartz, dickite, kaolinite and illite alteration. The alteration and mineralisation is classified as a high sulphidation, epithermal style resulting from the influx of hot, acid magmatic fluids. Preliminary land ownership, road access, power supply and mine infrastructure studies are in progress. The project is currently at an advanced exploration stage.

Jan 1, 1991

By N. B. Aughenbaugh

This report summarizes the results of an investigation into the causes of coal mine roof instability caused by the environmental characteristics of the air ventilated through a mine. The field studies, which were mostly in the Illinois Coal Basin, concentrated on collecting data of surface weather conditions, mine air characteristics (relative humidity and temperature), roof material types, roof movements, and characteristics of roof deterioration. The field studies revealed seasonal changes in weather are reflected in the mine air. The intake air undergoes rapid tempering along its course as it interacts with the ambient mine conditions. There are seasonal moisture interchanges between the mine rock and air, and a mine will lose more water than it gains on a yearly basis. The field studies also established that when the roof rock is shaley, seasonal changes in the humidity will cause roof deterioration because of the detrimental action of moisture on the shale. Roof falls were inventoried and classified by geometry. In the laboratory investigations, physical tests proved unreliable for evaluating shales for roof stability. The Franklin slake test lacks the sensitivity needed to differentiate shale durability for roof stability. A relative humidity test that reveals the sensitivity of a shaley rock to moisture change was devised. Environemntal chamber studies showed that neither temperature nor barometric pressure have a direct influence on shale durability. Photoelastic studies showed that the rate and depth of moisture absorption into a shale is controlled by bedding planes, fractures, and holes interrupting the exposed surface.

Jan 1, 1976

By Crazy Horse - The Journal of Explosives Engineering - Vol 20 No 1

The crew at Crazy Horse Memorial has produced a w o n d e rful new video called “The Fine Art of Mountain Carving.” The video closely examines for the first time, the extraordinary explosives engineering on the Crazy Horse mountain currently in pro g ress in the Black Hills of South Dakota. The 56-minute video takes the viewer up the mountain for a behind-the-scenes look at the drilling and blasting crew at work on the mountain. The video was written, edited and produced by Robb D e Wall and is available exclusively from the Crazy Horse Memorial in both DVD and VHS formats. For i n f o rmation, see www.crazyhorsememorial.org The following, is a brief summary of the 25 steps involved in carving the mountain. The video goes into extensive detail on each of the 25 steps. Both those in the explosives industry and those outside the industry will find the video intere s t i n g .

Jan 1, 2004

Development of a permanent human base on the Moon for exploration requires a self sustaining system. This entails production and processing of limited amounts of raw material on the Moon. Any mining and construction activities on the Moon can only be performed by a robust excavation machine that can excavate a variety of material from loose surface regolith to consolidated (frozen) regolith with embedded rocks in the mixture. Meanwhile, limited amount of information on lunar regolith is available to develop and optimize a machine for given lunar ground conditions. Therefore, any excavator designed for use on the lunar surface should have the ability to adapt to a wide range of operating conditions. A prototype cutterhead for the lunar excavator was built and tested at the Kennametal facility in Latrobe PA A. This paper discusses the results of initial material characterization as well as full scale tests of a prototype cutterhead inrelevent material. A brief review of anticipated production rates under various assumed ground conditions will also be presented.

Jan 1, 2009

By José Díaz Barrios

El proceso de la explotación minera de la veta Oroya Techo, perteneciente a la mina Casapalca, ha generado un desequilibrio del macizo rocoso, donde la energía que la roca de la caja, piso y techo (volcánicos de la formación Carlos Francisco) no pueden soportar mas allá del límite de su resistencia y deformabilidad natural, es liberada o “compensada” con el estrujamiento plástico de la veta Oroya Techo (estructura carbonatada). En ese sentido, el presente texto describe una manera de cuantificar dicha deformación a través del monitoreo de convergencias, donde se emplea un simple extensómetro de cinta manual y asímediante una análisis estadístico, seleccionar estaciones de convergencia por rangos de mediciones.

Sep 12, 2005

By Albert H. Fay

The first data compiled by the Bureau of Mines relating to coal- mine accidents in the United States were published in Bulletin 69," in which the total fatalities by years and States were tabulated from 1896 to 1912. Since the publication of Bulletin 69, further research has been conducted, with the result that the bureau is now able to publish for the first time all of the fatal accidents described in the State inspectors' reports by States, causes, and calendar years, from the beginning of inspection service to date. For the anthracite mines of Pennsylvania, there is a continuous record since 1870; the records of the Pennsylvania bituminous mines are continuous from 1877, and, with the exception of one year, the Ohio records are complete from 1874 to date. In fact, the records of all of the States, with few exceptions, are complete; and incomplete data for any year may generally be attributed to the fact that no report was published during that year. The magnitude of the coal-mining industry in the United States is such that too much stress can not be placed on the need of safeguard- ing the three-quarters of a million men employed. Although the figures given herein show an appalling record for past years, they are not published for the purpose of proclaiming the high fatality rate of the past. They are a record of experience covering a period of 45 years, showing causes and results of many accidents in the coal mines of the United States. They represent a diagnosis of the hazard of the mining industry, pointing out the principal physical causes of accidents, and make available a body of uniform facts that will serve as a basis of preventive measures for use in future operations. It is with these great purposes in view that the Bureau of Mines presents the classified data in this report. Classification and study of mine accidents on the basis of number of persons killed is common and very old, but fails to throw enough light upon the problem involved. Many serious accidents in mines have no fatal results, hence in a tabulation of fatalities they are overlooked and the real hazard of the industry is not made clear. An accident does not necessarily include an injury that may result therefrom. Such accidents as the breaking of a hoisting cable, an explosion of powder, gas, or dust, a runaway car or motor are all serious. Although no loss of life results, they should be recorded, investigated, and studied to prevent their repetition. No accurate data for the United States are available showing how far the personal element as related to the miner and his co-worker, the mine foreman, or to the superintendent and others in authority, contributes to accidents. Many accidents are due to inexperience on the part of the miner, his failure to heed orders, a misunderstanding of instructions and last, but not least, carelessness of himself or his fellow worker. A foreman or superintendent may fail to give proper warning regarding the conditions of certain parts of the mine; he may not have inspected certain rooms or entries on the day of a mine accident; the mine may not be properly equipped, or the operator may neglect to comply with the inspector's recommendations. There is, therefore, a personal element on the part of both the operator and the miner that must be considered. Legislation and the enactment of compensation laws will make the operator realize the seriousness of the mine-accident situation, when fatalities and injuries are to be paid for in legal tender of the realm. The miner must be educated and made to realize the dangers he encounters; he must learn that self-preservation and the safety of his fellow workmen should receive his first attention; he should cooperate with his employer, his asso- ciates, and the State mine inspector to the end that the mine hazard may be reduced to a minimum. "Cooperation for safety" should be the watchwords of the operator, miner, State inspectors, and all others in any way interested in the mining industry.

Jan 1, 1916

By D Thorburn

This paper reviews the history of environmental assessment in New Zealand with reference to mineral developments. Emphasis is given to larger more controversial projects particularly metal mines. The changing role and application of the Environmental Protection and Enhancement Procedures is examined in the context of changes in the government's environmental administration and the response of the Ministry of Energy's resource allocation group. Conclusions are drawn on the effectiveness of the present environmental assessment activities and on the allocation of administration of priorities in the Ministry. The Ministry of Energy has effectively ceased to exist.

Jan 1, 1990

TowerMill - Advantages in Wet Grinding Applications The TowerMill, which has now been in existence for no less than 50 years, is one alternative to the horizontal ball mill and offers several advantages. The TowerMill is widely used in (coal-fired) electric power plants for the grinding of raw material for the FGD (Flue Gas Desulphurisation) process involving very high throughputs, very fine product sizes and high availability. Some companies in the mining industry also looked at the use of such optimised grinding machines several years ago and found that many of the advantages offered in other industries are transferable to new applications. Much development work has been undertaken to improve the TowerMill for new applications and, as part of that work, tests have also been conducted to make direct comparisons of their performance with that of ball mills. Grinding tests were performed using the same raw materials and comparable machine sizes. Some of the results are discussed in this paper, along with a comparison of the advantages and disadvantages. The conclusion provides an outlook for some worthwhile future applications. The test results, which are described and analysed, show that the TowerMill offers significant advantages in relation to operating costs and operational safety. An example based on the wet grinding of limestone is presented.

Sep 13, 2010

By D. McSwain-Santos

Soda ash is the trade name for sodium carbonate, a chemical refined from the mineral trona or naturally occurring sodium carbonate-bearing brines (both referred to as natural soda ash) or manufactured from one of several chemical processes (referred to as synthetic soda ash). It is an essential raw material in glass, chemicals, detergents and other important industrial products. Production U.S. soda ash production during 2004 increased to10.9 million Mt (12 million st). Five companies comprised the domestic soda ash industry. Four were in Wyoming operating five plants. One was in California with one plant.

Jan 1, 2005

By A. Paulin, J. Roth, S. Spaic

This experiment was carried out to see whether copper-iron ingots from Late Bronze Age hoards could have been produced by smelting ferruginous copper ores. Since ferruginous copper-ores are chalcopyritic, chalcopyritic concentrate from a present day copper mine was dead roasted in our experiment in lieu of a rich chalcopyritic ore. Charcoal was used as a reducing agent in the reduction of calcine (i.e., a product of dead-roasting), and quartz sand was used as a flux. Two separate metallic solutions, a copper-base and an iron-base alloy, were obtained as a result of two factors: the presence of carbon and the miscibility gap in the Cu-Fe-C system. The metallic melts appeared in a form of bigger or smaller droplets, enclosed by a molten slag which, during the cooling, solidified into metallic beads. The presence of both metals was noticed in the majority of the examined beads. It was therefore concluded that calcine consisted of an intimate mixture of oxides of both metals which were simultaneously reduced during the reduction process. Due to the miscibility gap in the Cu-Fe-C system, separate iron and copper regions were formed in the beads. In both regions, sulphide inclusions were found. The formed molten copper and molten iron solution were found to be saturated solutions. The metallographic analysis revealed the precipitation of iron out of copper and that of copper out of iron during the cooling and solidification of melts. The formed slag contained little iron and no copper oxide.

Jan 1, 2001

Study on Selective Reduction and Magnetic Separation of Low-Grade Nickel Laterite Ore to Produce High Nickel Concentrate

Sep 13, 2010

By T. D. Parris

Within a 30-mile radius of Sudbury, Ontario, the Ontario division of the International Nickel Co. of Canada, Ltd., operates nine underground mines and two open pits. Prior to 1966, ore removal from the underground workings was mainly by scraping, using 125-hp electric slushers in blasthole and caving mining, and 30-hp or less air-operated slushers for fill- method mining. The development and evaluation of low-profile, diesel-powered front-end loaders, designed specifically for underground operations, was followed with keen interest during the period 1964-1965.

Jan 6, 1969

Effect of pH and Chain Length on the Flotation Separation of Fluorite from its Synthetic Mixtures with Calcite and Dolomite with Imino-Bis-Methylene Phosphonic Acid

Sep 13, 2010