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By T. Guyaguler

An analytical technique using computer-based multiple-regression methods was employed to determine the relation between the dust-producing index and inherent rock properties of typical samples from a coal-producing area, one of the aims being to provide a preliminary predictive tool for practical use. The investigation demonstrated that factors varied in their influence under different conditions, the brittleness:toughness ratio and the hardness being the most significant inherent properties with hardness showing the highest positive correlation coefficient

Jun 13, 1905

By Huayi Yin, Wang. Dihua, Wei Xiao, Xuhui Mao, Diyong Tang

"The world production of crude steel reached 1.55 billion tons in 2012,which generated ~2.5 billion tons of CO2. Electrochemical metallurgy especially through high temperature molten salt electrolysis with renewable electricity stands for a great opportunity for producing “green” metals. In recent years, electrolytic production of iron without emission of CO2 in different molten salt systems has been reported. A cost-affordable inert anode is the key to produce acceptable eco-friendly iron by the novel molten salt electrolysis processes. Based on the authors’ research, this paper will discuss iron production by molten salt electrolysis using a nickel alloy inert anode. On the other hand, the paper also covers a novel molten salt CO2 capture and electrochemical transformation (MSCC-ET) process, in which CO2 is effectively converted to value-added carbon and oxygen in a molten bath using a cost-affordable nonconsumable SnO2 anode.1. IntroductionEnergy and materials are cornerstones to support the development of human society. The traditional primary metal production, especially iron and steel, and electricity production are mainly based on the reactions between carbon (coal) and oxygen (represented by equations (1) and (2) respectively), which produce huge amount of CO2.MxOy + 0.5y C = x M + 0.5y CO2 (g) + Q1 ( 1 )C + O2 (g) = CO2 (g) + Q2 ( 2 )In 2012, the world production of crude steel reached 1.55 billion tons, of which 46.3 %, ~0.7165 billion tons were produced in China. Based on the average level of 1.7t CO2 emission per ton steel, more than 1 billion tons of CO2 generated from steel industry in China in the year. Besides the iron and steel industry, thermal power plant leads the CO2 emission in both USA and China. The total consumed electricity in China increased to 4959 billion kWh in 2012, ~70% of it was from coal fired power plant. The average CO2 emission for electricity production in the typical thermal power plant in China is around 0.78 kg kWh-1. It accounts for ~ 3.868 billion tons of CO2 emission from thermal power plant in 2012 in China."

Jan 1, 2014

By Peter Kowalczyk

Magnetic surveying and map production is well established in land based mineral exploration. Magnetic data are routinely used to map geology in covered terrains, to estimate the depth to basement in overburden covered areas, and to identify altered zones, mineralization, bedding attitudes, and fault networks both regionally in map view, and through interpretation to depth in 3D. Best practices for magnetic survey methods and magnetic interpretation exist in all areas of land based geophysical survey methodology - mineral exploration, hydrocarbon exploration, geological mapping, archeological mapping, and in military applications. At sea, and particularly under the sea, sophisticated magnetic surveys are being done, but it can be argued that these are primarily in niche applications, for example in naval mine-hunting and UXO applications. Magnetic data is not normally collected on AUVs and ROVs conducting mapping and hydrographic survey operations. OFG has developed physical and mathematical calibration routines so that magnetometers can be mounted directly onto AUV and ROV bodies where significant heading errors and magnetic gradients exist. This simplifies the routine deployment of magnetometers on AUVs and ROVs for mineral exploration and other magnetic survey applications without the need for towed bodies, ungainly mounting frames, or degaussing of the survey equipment. Our experience shows that magnetometers can be operated routinely on AUVs and ROVs and that with careful processing useful maps can be produced routinely at low cost.

Sep 1, 2014

By H von Blottnitz, J L. Broadhurst

Eco-efficiency has been proposed by the World Business Council on Sustainable Development as an environmental performance indicator framework that contributes to sustainability by assisting corporate decision makers improve the environmental performance of their operations and processes, while also extracting additional economic value. Given that the recent engagement of the minerals industry with sustainability has highlighted the need for requisite tools and methodologies, it is therefore of interest to assess whether eco-efficiency indicators can drive sustainability performance improvement during process design within the minerals industry. Previous work indicates that the choice of sustainability performance indicators to be used for decision making needs to be governed by the decision context; ie the performance indicators need to be fit-for-purpose. Here, the strengths and weaknesses of eco-efficiency indicators are analysed using case studies. First, a more rigorous definition of eco-efficiency indicators for the minerals industry is proposed based on indicators currently offered in the literature. Two case studies are then selected to reflect typical decision situations encountered within minerals process design. For each case study, eco-efficiency indicators are computed and are compared to more traditional graphical representations of the economic and environmental performance of process design alternatives considered. The sensitivity of these indicators to various process design parameters is also investigated. Results confirm that the meaningful application of eco-efficiency indicators is strongly dependent on the decision context in which the process data is generated. Results also show that eco-efficiency indicators can be related to technical process design parameters to allow for richer communication of performance information for various decision trade-offs; however, in some cases, graphical approaches that provide more insights into the environmental-financial trade-offs should be preferred. The research thus contributes to guiding the selection of the appropriate tools for more environmentally sustainable design of minerals beneficiation processes.

Jan 1, 2009

By O. M. Bishop

From October 1943 to March 1944, the Bureau of Mines conducted core drilling at the Victory fluorspar mine, Hardin County, Ill. to test the Fredonia limestone and the included sub-Rosiclare sandstone zone beneath the existing stopes. Twenty-one vertical holes were drilled to an average depth of 60 feet. Ore was penetrated in six holes. Since its discovery in 1927, the Victory mine has produced approximately 5 percent of the total fluorspar mined in the United states after that date. The ore discovered in the early mine development is now exhausted, except that contained in pillars drifting to the northeast has partly developed one substantial ore body, and company drilling has indicated another nearby. The increasing need for fluorite for war use in 1943 suggested the desirability of mining the pillars, provided it could be established that no ore beds existed below the stopes or in areas to which access would be obtained through the present workings. This work describes the work accomplished during the project and presents the data obtained.

Jan 1, 1948

By J. K. Ahlness

The Bureau of Mines investigated technologies for determining the integrity of in situ leach mining wells. A self-contained trailer-mounted well integrity testing system (WITS) was designed and built to enable rapid testing of well casings for leaks as required by environmental regulations. The WITS utilizes two inflatable packers to seal off the entire casing length or any portion thereof. Water pressure is built between the packers to the desired test pressure, and the presence or absence of casing leaks is determined by monitoring the pressure drop between the packers. A winch and steel cable are used to run the packers in and out of the well. The WITS underwent an industry field test at the Irigaray in situ uranium leaching mine near Buffalo, WY. A total of 37 wells with an average depth of 225 ft (69 m) were tested at an average rate of four wells per 8-h shift with a two-person operating crew. This represents a 75-pct time savings and an 83-pct labor savings compared to the rigid-pipe method previously used at the mine, with which a three-person crew tested an average of one well per shift.

Jan 1, 1986

By Earl R. White

In 1950 Kaiser Steel Corporation acquired control of the Utah Fuel Company, a pioneer Utah coal concern owning large reserves of high volatile coking coal near Sunnyside, Utah. The mines at Sunnyside have been producing high quality coking coal since the late 1890's. Kaiser Steel acquired the coal deposits at Sunnyside in order to supply the necessary coke for its steel plant at Fontana, California. The Sunnyside coal deposits are made up of two mineable beds, the upper and lower Sunnyside seams. Both seams outcrop along the southward facing escarpment of the Book Cliffs. The coal seams dip under the massive sandstones of the Book Cliffs to the northeast at 5 to 22 pct., with the steepest-part being near the outcrop. Mining at Sunnyside up to 1961 had been carried on with room and pillar methods. The deep cover and rotten roof conditions, along with the need of increased tonnage, required a change of mining technique. Numerous ideas were presented, discussed, and economically analyzed. Several people involved in these discussions, with the aid of W.W. II, had been introduced to the European methods of coal mining, namely the longwall technique. The European mines had long been plagued with near similar conditions as those at Sunnyside, particularly the deep cover problem. The longwall method seemed to be working very well under these conditions, and with the extensive studies given longwalling by the Kaiser Steel mining officials, it was decided to give longwalling a try.

Jan 1, 1976

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. A. Padgham, J. A. Brophy

About 85 % of the 350 tonnes of gold produced by 25 mines in the onhwe t Territories (NWT) since 1935 has come from the Yellowknife-area mines, Con and Giant , which exploit shear zones in Archean mafic volcanic of the Slave Structural Province. Four percent of the total production has been from Archean iron formation-hosted depo its, mainly from Lupin Mine, which today produces more gold than Con and Giant combined and has been primarily responsible for the increase of WT gold output from 5 to 12 tonne per year since 1981. The remaining gold ha been won from the following deposit typesall but the last being in Archean rock : sedimentary-volcanic contact depo its uch a Discovery and Salmita (10 %); turbidite-hosted quartz-vein depo its uch a Camlaren and Ptarmigan (1%); Proterozoic deposits such as Shear Lake and Fox (1#) . All but I% of WT gold has come from the Archean Slave Structural Pro ince, which is also the premiere exploration area for gold deposit types that have yet to be productive in the NWT. These types include stratabound gold in mafic and in felsic volcanic rocks (eg. , at Indin Lake and Courageous Lake, respectively) as well as gold in plutonic rocks (eg. Anialik Gnei Complex). Deposits similar to those in the Slave have al o been found in the Archean Ennadai Belt of the Churchill Structural Province. In the Cordillera. there is potential for placer gold and for gold associated with Cretaceou intrusions.

Jan 1, 1986

By Russell Spry

THE cyanide plant of the Cariboo Gold Quartz Mining Company, Limited, at Wells, B.C:, in the Barkerville section of the Cariboo mining division, was erected during the latter part of 1932 and placed in operation in January, 1933. The initial capacity of the plant was about 50 tons daily. This was increased to 100 tons at the end of 1934 and stepped-up to 150 tons in September, 1935. It is expected that further plant extensions, for milling a total of 200 tons daily, will be required during the early part of 1936. Recent additions to the mill have been so planned as to permit ready expansion to 275 tons daily when underground development warrants the milling of this tonnage. It is the purpose of this paper to outline briefly the steps taken to bring the plant to its present capacity and to comment on possibilities for further plant expansion. The gold in Cariboo Gold Quartz ore occurs as free gold in the quartz and on pyrite surfaces. Some of it is very finely divided, specks l/10,000 inch having been observed microscopically, according to Dr. G. Hanson. In addition to pyrite, which comprises probably 15 to 20 per cent of the mill feed, galena and sphalerite are present, with small amounts of arseno-pyrite and chalcopyrite. Sulphobismuthites-chiviatite, galenobismutite, cosalite, etc.-occur more or less frequently in certain sections of the mine. Following tests on Cariboo ore by the Mines Branch, Department of Mines, at Ottawa, treatment of the ore by straigh t cyanidation was recommended and a 50-ton plant employing continuous counter-current decantation was erected. This plant was built as a pilot mill, the intention being to erect a larger mill after metallurgical treatment had proved successful over an extended period. This original installation, however, has been enlarged and retained as an operating unit, additional equipment being added to it as capacity increases have been required.

Jan 1, 1936

By Qingguo Xue, Jingsong Wang, Guang Wang, Yuanyuan Zhang

Due to complicated structure and composition of high-phosphorus iron ore, pure substances were used to simulate the chemical composition of high-phosphorus iron ore to study the reaction of fluorapatite at different temperatures and effect of additives. The gasification process of P during carbothermic reduction process was investigated using a quadrupole mass spectrometer gas analysis. It is found fluorapatite was reduced to phosphorus which diffused into iron and gas phase. From the gas analysis, it was observed that PO and P gas species were vaporized around 800 °C. As the reduction temperature increased, the diffusion of phosphorus into iron was enhanced. The presence of Ca(OH)2 as additives not only promoted the reduction of iron oxide, but also decreased the degree of fluorapatite reaction to inhibit P into iron.

Mar 1, 2018

By Jiling Wang, Xuefeng Liu, Haojian Duan, Lifeng Zhang, Ying Ren, Wen Yang

"In order to study the influence of MgO-C refractory on steel cleanliness and inclusions during steelmaking process, and to understand the reaction mechanism deeply, laboratory deoxidation and equilibrium experiments were respectively performed in MgO crucibles at 1873K. In the former experiment, after Al addition, steel samples were taken at different holding time. In the latter experiment, different slag components and different contents of carbon and aluminum in steel were considered respectively. The inclusion characteristics of each experiment were analyzed. The results showed that with the increasing of holding time after deoxidation by Al, MgO existed in the small inclusions firstly, and then in the large ones such as the clusters. The MgO content in the inclusions increased with the increasing of holding time, indicating that the MgO in crucible could be individually reduced by the aluminum in the molten steel. The reaction could occur within nine minutes.IntroductionNon-metallic inclusions would have positive or negative effect on steel quality depend on the quantity, size and composition of inclusions. Large inclusions are always detrimental. From the point of view of inclusion property, plastic inclusions are required by steel cord, while hard inclusions are preferred by pipeline steel. One of the most important ways to increase the steel quality is reducing the inclusion size and controlling the inclusion composition in steel. Nowadays, MgO based refractory is used as ladle glaze material with more and more frequency, which results in different inclusion characteristics in molten steel, for example, the inevitable generation of MgO contained inclusions during ladle treatment of steel. In other words, the inclusions in this type ladle will influence on the steel cleanliness and the product property. Thus, keeping an eye on the inclusion formation behavior in the steel with MgO-C ladle glaze is important for the steel industry. There have been a few studies in this regard. Li et al[l] studied the reactions between MgO-C refractory, molten slag and metal using a high temperature X-ray radiographic apparatus. They found that the local corrosion was regarded as due to the cyclic dissolution of MgO and graphite in the refractory into slag and metal phase. The gas bubbles formed according to the reaction of (FeO)+C(s)=Fe(l)+CO(g) greatly influenced the corrosion. On an industrial scale, Du[2] found that ladle glaze is a major source of inclusions in the ladle. An experimental study has been performed by Lehmann in order to estimate the importance of the reaction between a MgO-based tundish refractory and an Al-killed steel[3]."

Jan 1, 2014

By W. P. Sykes

SEVEN years ago, Dr. S. L. Hoyt1 presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. STEPS IN PREPARATION While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows: 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By X. K. Jiang

Pneumatic, triboelectrostatic processing of physical mixtures containing fine (-200 mesh) particulate may have significant application potential in the mining and energy industries. Such dry processing methods, especially for finely comminuted materials, have not been examined in as much detail as wet processing methods nor have been part of the training or education of mining and process engineers. We have examined fundamental and applied physical and engineering factors controlling triboelectrostatic beneficiation of fine-sized physical mixtures, one of which -combustion fly ash -has size, heterogeneity and mineral concentrations typical of those expected in mined minerals. The applicability of dry processing, however, cannot be readily evaluated because of the unavailability of standard procedures for process assessment.

Jan 1, 1999

By P. Bermingham

A new approach to load testing of high capacity piles is presented. The method is mobile, inexpensive, repeatable and non-destructive allowing for multiple pile testing at a single site. A reaction mass is placed over a pressure chamber situated atop the pile to be tested. The test method is significant in that it can produce linearly increasing forces of high magnitude (over 5.0 MN) with durations of up to 80 milliseconds. This represents pulse durations an order of magnitude longer than achieved using a drop hammer. The accelerations the pile undergoes are less than one g, (conventional dynamic methods = 50 to 100 g). These effects combine to produce pile behaviour no longer dominated by the action of stress wave, instead the pile is under high levels of stress through its length during the force input. This is representative of the situation when static loads are applied, thus the method may be considered quasi-static. Further advances introduced with this method are that pile deflection and transmitted force are measured directly by means of a laser beam and load cell. This allows accurate correlation of event load displacement histories without the error associated with zero shift (acceleration integration) or non-homogeneous materials (strain measurement). The load displacement histories emulate those obtained for static load testing.

Jan 1, 1989

By Russell E. Griffin

The current state-of-the-art of fire and smoke detection technology is reviewed from the standpoint of suitability for use in underground metal and nonmetal mines. Detection modes, fire signatures, and environmental considerations are included. Preliminary results of long-term in-mine tests are presented.

Jan 1, 1979

By M. G. Corson

THE theory of hardening by interference with slip which has been so clearly developed by Jeffries and his co-workers requires that an alloy to be amenable to age or heat hardening should contain among its components some that will stay in solid solution at high temperatures and precipitate as a secondary phase on cooling. This secondary phase may be either a more or less pure individual element (chromium in the case of copper, anti-mony in the case of lead), or some intermetallic com-pound. Those cases of hardening which depend on the precipitation of a compound are not only the most frequent, but are also far superior in the efficiency of hardening obtained. However, the slip interference theory as stated in its most general form is not sufficient to foretell new cases of this type of hardening and also will not explain some phenomena of a more intricate nature. It is not sufficient that a secondary phase might be absorbed by the main one at high temperatures and precipitated at the lower ones. The kinetics of this precipitation and the accompanying. physical phenomena of dimensional changes play independent and highly important parts. These kinetics, while not yet sufficiently studied to he formulated in the shape of physicochemical equations, might find their expression-in a qualitative systema-tization of the phenomena of precipitation according to two different viewpoints. To begin with, we encounter the question as to the velocities of the precipitation and of the growth of the phase precipitated. To harden a metal in an efficient manner we must be able to control the precipitation on one hand and also to bring the total of the secondary phase to such a number and size of the particles pre-cipitated as, will produce a desirable hardening effect under commercially feasible conditions of. age or heat hardening. From this viewpoint six different cases may be dis-cerned.

Jan 7, 1928

By H. Wotruba, K. Neubert

Dual-energy X-ray transmission (DE-XRT) imaging is known from safety luggage inspections at airports. The use of DE-XRT technology for sorting applications in the primary raw materials industry has been the subject of numerous investigations. Beside other metal ores, X-ray transmission sorting is already used for the preconcentration of tungsten ore, gold ore and coal. The applicability of DE-XRT sorting is limited to ore types where differences in metal concentrations are measurable, based on an interpretation of X-ray images. Metal contents in particles occur in large varieties in terms of concentration, grain sizes, spatial distribution and mineralogy and therefore influence the X-ray absorption. As a result, each ore has to be tested individually for its suitability for DE-XRT sorting. The objective of current research at the Department of Mineral Processing (AMR) at RWTH Aachen University is to assess parameters influencing the detectability of rare earth oxides. Two approaches were followed: (1) Practical test work, based on artificial ore samples of defined compositions and (2) Computer-based simulation of absorption features of identical particle compositions. In total, more than 300 artificial samples of various compositions and metal grades were produced and X-ray images from DE-XRT sorting were analyzed. Results from the DE-XRT sensor were put into correlation with metal grades and particle sizes, to analyze influences and limits on the detectability of rare earth oxides. In addition, a new approach was tested in which the X-ray absorption of particles of various compositions was determined based on a Monte Carlo (MCNP) simulation. During the simulation, similar compositions, as used for the artificial samples, were tested and the X-ray absorption behavior during DE-XRT sorting was determined. A comparison of results from both approaches is used to assess the applicability of the MCNP-simulation for the prediction of the X-ray attenuation behavior during DE-XRT sorting.

Jan 1, 2016

By I Hustwick

New Zealand Steel Mining Limited operates two independent sand mining operations on the West Coast of the North Island of New Zealand. Waikato North Head 30 km south of Auckland supplies ironsand concentrate as the raw feed for New Zealand Steel's works at Glenbrook and Taharoa 70 km further south, exports ironsand concentrate to Japan.   Taharoa uses two sets of six low pressure Warman centrifugal pumps in series to load bulk ore carriers 3 km off shore through two underwater pipelines. Waikato North Head delivers the ironsand to Glenbrook 18 km through a 200 mm ID buried pipeline using two stages of high pressure positive displacement (HPPD) pumping.   A high level of operating and maintenance expertise has been developed since commissioning the two systems which are proving to be reliable, efficient and of minimal impact environmentally.

Jan 1, 1990