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By Lyon F. Terry

INCREASING domestic demand for products, a sharp reduction in exports to Europe, and a rise in imports from South America were the chief features of the economic side of the industry in 1940. As the war progressed it became evident that exports to former European customers were being cut off or drastically reduced, leaving heavy inventories of products in the hands of many American refiners who had anticipated larger demands from the belligerents. Stocks of motor fuel reached burden-some proportions early in the year for the added reason that refining operations were stimulated by heavy demand for heating oils. Excessive tanker rates for Gulf to Eastern Seaboard movements during the first part of 1940 contributed to the accumulation of products on the Gulf Coast, where refinery gasoline prices were forced to extremely low levels by midyear. Tanker rates receded to normal during the summer but have since risen again to the approximate equivalent of pipe-line tariffs from the Mid-Continent.

Jan 1, 1941

By Mike Dry

While McCabe-Thiele plots are useful for designing single-component solvent extraction systems, not least because of their simplicity, they are less useful for multi-component solvent extraction. This paper presents a relatively simple method, compared to other approaches, for modelling solvent extraction as chemical equilibrium reactions between the various aqueous and organic species. The essence of this approach is how values for the equilibrium constants can be extracted from standard laboratory data. Synergistic solvent extraction of nickel is used to illustrate the method.

By Frank E. Cash

The iron-ore ranges in the Lake Superior district are the liarquette in Michigan, Menominee and Gogebic in Michigan end Wisconsin, and the Vermilion, Mesabi, and Cuvuna in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years. During the 4-year period 1940 to 1943, inclusive, 323,667,599 long tons of iron ore was shipped from the Lake Superior district.4/ Michigan and Wisconsin shipped 65,386,608 tons, or 20.2 percent of the total, and employed approximately 15,000 men; Minnesota shipped 258,280,991 tons, or 79.8 percent of the total, and employed approximately 10,000 men. The tons produced per man employed is much, greater in Minnesota than in Michigan and Wisconsin owing to the large open-cut production in Minnesota.

Jan 1, 1945

By X. L. Song

In this paper, ZrSiO4-Cd(S1-xSex) inclusion pigments were synthesized by hydrothermal method. Microstructure, morphology and properties of the powder were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared spectroscopy (IR) and CIE chromaticity, respectively. It shows that, precursors obtained at pH is about 6.0 are sol and products with higher crystallinity, red hues (a*=38.23) and inclusion ratio when hydrothermal synthesis temperature is 180? and holding time is 12h. Hydrothermal reaction mechanism was further analyzed as well. In particular, an ideal model of pigment formation was proposed.

Jan 1, 2014

By David N. Hedges

This paper discusses the actual recovery and installation of a longwall in a bituminous coal mine in Western Pennsylvania. The coal bed mined is in the Lower Freeport seam which averages 42 inches (1.07m) in height locally. Drainage from the mine is approximately 3.5 million gallons of water per day (13.25 million liters per day). This water deteriorates the mines predominately fire clay bottom making it extremely difficult to move equipment. Support removal is accomplished by pulling the 6 ton (5443 kg) shields out under their own hydraulic power and transporting them by track over four miles (6437m) co the next longwall panel. This paper also discusses the changes that will be made to aid in the succeeding longwall recoveries and installations.

Jan 1, 1984

By Walter Knox, J. D. Doherty

In 1939, at the request of The Koppers Coal Co., the Koppers Company Research Department established a Stoker Coal Research Laboratory for the purpose of investigating the performance characteristics of stoker coals in typical domestic stoker installations. Fig. I is a photograph of part of the laboratory. The material in this paper deals with the performance of one coal in a single installation. Presented are details of this installation, mechanical characteristics of the stoker, and the results of a series of burning tests in which adjustments were systematically varied. Summary OF Results Mechanical Features I. A large percentage of the total power consumed by a domestic stoker is used to operate the gear case and motor (Fig. 3)- 2' The power consumption per ton goes down with an increase in rate of coal feed (Fig. 4). 3. The automatic air control in this stoker showed advantages Over manual control (Fig. 5). 4. The air velocities through the retort tuyeres were uniform around the retort, but varied between the rows of tuyere rings (Fig. 6). 5. The crushing of coal with this stoker increased the minus 1/8-in. from 11.6 per cent to 19.2 per cent. There was a notice- able segregation of coal as it came from the retort and distribution was not uniform (Fig. 7). 6. Measurement of air entering over the fire showed that with some not uncommon adjustments this air may be a high percentage of the total air supply (Fig. 8 and Table I). Operating Performance ,. The, removal of clinker was shown to give a period of poor performance characterized by a high fuel-bed resistance and a high percentage of carbon monoxide in the flue gases (Fig. 10). 2. The fuel-bed resistance was found to decrease as the fuel bed built up in a normal response to heat demand after a prolonged hold-fire (Fig. II). 3. with intermittent operation the burning rate was almost always less than the feeding rate, The wide variations were found to be greatly dependent upon the length of the On period and the length of the intervals between On periods (Fig. 12). 4. The maintenance of a low furnace draft led to less fly ash, better clinker formation, and higher efficiencies (Fig. 13). 5. The maintenance of a minimum of excess air also resulted in less fly ash, better clinker formation, and higher efficiencies (Fig. 14). Guiding Principles In planning the investigations, the following principles were adopted: Selection of Heating Equipment.—Use only standard models of stokers and furnaces representative of those widely used.

Jan 1, 1942

By Walter Knox, J. D. Doherty

In 1939, at the request of The Koppers Coal Co., the Koppers Company Research Department established a Stoker Coal Research Laboratory for the purpose of investigating the performance characteristics of stoker coals in typical domestic stoker installations. Fig. I is a photograph of part of the laboratory. The material in this paper deals with the performance of one coal in a single installation. Presented are details of this installation, mechanical characteristics of the stoker, and the results of a series of burning tests in which adjustments were systematically varied. Summary OF Results Mechanical Features I. A large percentage of the total power consumed by a domestic stoker is used to operate the gear case and motor (Fig. 3)- 2' The power consumption per ton goes down with an increase in rate of coal feed (Fig. 4). 3. The automatic air control in this stoker showed advantages Over manual control (Fig. 5). 4. The air velocities through the retort tuyeres were uniform around the retort, but varied between the rows of tuyere rings (Fig. 6). 5. The crushing of coal with this stoker increased the minus 1/8-in. from 11.6 per cent to 19.2 per cent. There was a notice- able segregation of coal as it came from the retort and distribution was not uniform (Fig. 7). 6. Measurement of air entering over the fire showed that with some not uncommon adjustments this air may be a high percentage of the total air supply (Fig. 8 and Table I). Operating Performance ,. The, removal of clinker was shown to give a period of poor performance characterized by a high fuel-bed resistance and a high percentage of carbon monoxide in the flue gases (Fig. 10). 2. The fuel-bed resistance was found to decrease as the fuel bed built up in a normal response to heat demand after a prolonged hold-fire (Fig. II). 3. with intermittent operation the burning rate was almost always less than the feeding rate, The wide variations were found to be greatly dependent upon the length of the On period and the length of the intervals between On periods (Fig. 12). 4. The maintenance of a low furnace draft led to less fly ash, better clinker formation, and higher efficiencies (Fig. 13). 5. The maintenance of a minimum of excess air also resulted in less fly ash, better clinker formation, and higher efficiencies (Fig. 14). Guiding Principles In planning the investigations, the following principles were adopted: Selection of Heating Equipment.—Use only standard models of stokers and furnaces representative of those widely used.

Jan 1, 1942

By G. Girard, A. Larouche, J. Colbert, G. Doyer

"The Direct Chill (DC) casting process uses water to extract heat from molten aluminium and helps to control the solidification process. Many factors such as the water flowrate, water distribution around the mould and water impingement angle have significant impacts on the solidification process. It has been noted that the chemistry variation of the cooling water is also an important factor that has a major impact on the presence of defects on the ingot. A significant change in the water quality can produce defects on the ingots such as cracks, bleedouts, or runouts. Understanding the impact of water quality variation on ingots is therefore essential to ensure good ingot production and reduce defects. This paper aims at describing a new approach to follow the variations of process water quality over time. It is an original and innovative method, which is still under progress. A water quality and stability index (WQSI) is under development to evaluate changes in the water composition based on water physico-chemical parameters. The index is calculated by comparing each of the actual parameters with historical values previously modeled by a statistical law. It is a dimensionless number having an adjustable weight factor for each parameter. The positive or negative contribution of each parameter, with respect to the water cooling capacity, is taken into account to calculate the WQSI. The current selection of parameters is based on knowledge from the literature as well as on empirical experience. When the developed tool will be mature, it could be used to track water variations upon time and anticipate problems, enabling proactive actions to ensure good ingot production.INTRODUCTIONFor many years, the impact of water chemistry on heat transfer, during DC casting, has been of great interest in the aluminum industry. Several papers have been published to demonstrate the correlation between water chemistry and heat transfer (Yu, 1985), (Gildemeister, 2014). Although numerous studies do present the effects of water parameters (i. e. hardness, conductivity, oil, and grease…) on cooling capacity under controlled experimental conditions, they do not reflect the strong interactions between the parameters and variations present in a casting center. Wells and Cockcroft also demonstrated that laboratory based studies are not fully representative of real heat transfer in an industrial casthouse, there are too many factors involved (Wells, Li, & Cockcroft, 2001). In this context, it becomes very difficult to obtain a quantifiable relationship between the capacity of water to cool the ingot and ultimately the performance of the cast."

Jan 1, 2016

By Seyyed Mehdi Radeghi Mehrjou

The current work investigates the behavior of inclined micropiles under seismic loads. The dynamic finite element method (FEM) was employed. Rayleigh damping was applied to the soil, and elastic beam elements were employed to model the micropiles. The micropile structure was assumed to have one degree of freedom as a column with concentrated mass. The numerical modeling of micropiles was performed to explore the effects of their inclination on their seismic performance within homogeneous soils with uniform stiffness. In addition, the effect of soil stiffness was studied by considering various stiffness in soil depth. The results from the studies have shown significant effects on the dynamic amplification and internal seismic-induced loads of inclined micropiles.

Sep 1, 2022

By Ned Baker

Details are given of a fuel-induction system for a hydrogen, fueled engine. The induction system was designed to preclude backfire otherwise common in hydrogen fueled engines. System features and test data are presented and discussed in the context of the requirements peculiar to use in an underground mine environment. The fuel induction-system when tested in conjunction with a modified Caterpillar 3304 engine provided backfire free engine operation and satisfactory engine performance.

Jan 1, 1982

By Joseph A. DeCarlo

THE TOTAL VALUE of sales of coal-chemical materials in the 10-year period 1948-57 increased 34 percent or at an average annual rate of approximately 3.5 percent. According to the Chemical Industry Facts Book, third edition, 1957, published by Manufacturing Chemists' Association, Inc., the production of industrial chemicals since 1939 "has grown at au average rate of about 10 percent" a year (p. 7). The rapid growth of the chemical industry increased requirements of chemical raw materials at a faster pace than could be supplied by coal carboniza¬tion, and view sources of supply became necessary. The petroleum industry in the past decade increased tremendously the flow of chemical raw materials to the chemical industry through the processing of crude petroleum and natural gas. Whereas coal carbonization supplied most of the raw materials for manufacturing synthetic organic chemicals before World War 11, coke ovens supplied only about 40 percent of the total used in 1957. Although the proportion of chemical raw materials supplied to the chemical industry by coke-oven operators declined, this source of supply is large and important to our economy. In 1957, the value of coal-chemical materials sold, including surplus gas used by producing companies, totaled $358 million, compared with $267 million in 1948. Major factors that contributed to this gain were (1) increased production of all coal chemicals and (2) higher prices for tax and light-oil products. Gains in output of coal chemicals resulted principally from expansion in carbonizing capacity of coke plants owned and operated by the iron and steel industry, as yields of the basic coal¬-chemical materials (tar, ammonia, light oil, and gas) varied only slightly during the 10 years under review.

Jan 1, 1959

By J. C. Cook

In solution-mining of underground salt and similar minerals, using drilled wells for access, it is desirable to monitor the lateral growth pattern of the resulting fluid-filled cavern. Therefore, a process of seismic surveying from the surface of the ground has been conceived in which the amplitudes of waves reflected from and transmitted through the soluble formation are measured. The large acoustic impedance contrast between solid and fluid should produce striking amplitude anomalies, especially if shear waves are employed, since thick fluid bodies are opaque to shear waves. Horizontally-polarized (SH) shear waves are best for preventing conversion to P waves at the numerous horizontal interfaces in the ground. Field tests to date have shown that a truck-mounted, half-ton hammer striking horizontally against the end of a trench produces usable SH-wave energy at lateral distances up to about 850 ft. Horizontally-directed explosive wave sources were effective to about 2000 ft. Conventional magnetic-tape recording and processing were used, but with the detecting geophones oriented to favor SH waves. An irregular solution cavity in bedded salt at 500-ft depth has apparently been located by SH-wave and SV-wave reflections. Further field work is planned to corroborate and extend this result. The Brine Cavity Research Group, an association of 11 chemical and salt producing companies, is supporting this work. Major deposits of salt in tabular beds lie beneath some 300,000 sq miles of land in the central and northeastern U.S. This salt is a basic source of soda ash and chlorine, and has been extracted as brine from drilled wells for about a century. During the past two decades, the U.S. solution-mining industry, following the lead of European operators, has greatly improved the extraction process through the application of engineering and science.' In 1957, the Brine Cavity Research Group, an association of 11 chemical and salt producing companies, was formed. This group proceeded to attack certain common problems through the support of research. An outstanding problem has been that of determining the shape and location of the growing solution cavities in the underground salt, so that measures can be taken to maintain operating efficiency. The problem has been partially solved by the Dowel1 sonar mapping service, which employs a pulse-echo device lowered into the cavity through the well.2 However, the working range of this equipment is at present insufficient for large cavities, and echoes are not returned from highly sloping walls nor from behind such obstructions as rock debris. Therefore, an independent means of mapping the cavity, for example, from the surface without interfering with operation of the well, would be desirable. THEORY OF THE METHOD Seismic waves are the only physical agent known to be capable of sufficient resolution and penetration to define typical solution cavities from the surface of the ground. The geometry is unfavorable: cavity widths are generally less than half their depths below the surface; resolution and lateral location of boundaries and channels to within 50 ft at depths of 500 to 3000 ft is desirable. Conventional seismic surveying, as used for petroleum prospecting, is probably not the answer: isopach mapping, for example, is not thought accurate enough to define the cavity by the slight additional delay time it would introduce (of the order of 0.005 sec for a 50 ft-thick cavity in hard Paleozoic rocks). Refraction surveying has also been considered, but seismic specialists see little promise in it for this problem. In 1957, in correspondence with industry personnel, the writer suggested a seismic method based upon careful measurement of reflection amplitudes. As Table I illustrates, seismic reflection coefficients r for typical brine-rock interfaces are considerably higher than those for typical interfaces between different kinds of solid rock. This fact can be utilized in two ways, illustrated in Fig. 1: 1) If the cavity roof is reasonably flat (which it may sometimes be since the unsaturated top brine will be in contact with an insoluble rock stratum), extra-strong seismic reflections will be received from the salt stratum where the solid has been replaced by liquid.

Jan 1, 1964

By Thomas Oberndorfer

INTRODUCTION Since several years the author is engaged in research activities in the field of mining method modelling (Oberndorfer, 1993 and 1994). The initial goal was to improve and assist the selection of the most appropriate mining method. However during investigations it became obvious that the most beneficial application of computer support is the fast calculation of numerical assessment rather than the consideration of all, i.e. also qualitative, criterions necessary for final decision. Numerical results serve - together with qualitative considerations based on the experience of the mining engineer - as a basis for decision. The emphasis is on "fast" calculation, as only this property makes it possible to calculate and compare many distinct variations. As long as no procedure exists, which optimizes all involved parameters, calculating many variations is of great important, because it is the only way to increase the chance to pick a alternative "close to optimum", but also to learn about the sensitivity the result will react on changes of input parameters, which are rarely known exactly. Generally speaking many trials give a better basis for final decision. It is no secrete that the most important obstacle towards quick calculations of a series of alternatives is not the processing time of the computer, but the time required for setting the input data in way that the computer can start processing, which is usually inter- active man work on the screen. Furthermore usually several distinct programs are required to cover the whole range of involved problems, with corresponding problems in automatic data transfer. The research work's goal was to overcome these problems. The approach developed was to describe a mining method more in a theoretical way (i.e. to give the computer some degree of "consciousness" on mining methods), which then can be applied under any specific conditions. E.g. a cut-and-fill operation will be "generally" the same in narrow or thick deposit areas, but the resulting keyfigures, e.g. total tonnage, productivity, dilution and loss, or finally costs per ton, will differ significantly. The approach (MMM = mining method modelling) presented reflects a deduction from the general case to a specific one (rather than the other way round). The developed model is general enough to be applicable to any mining method, and also to any degree of precision the mining method should be described, contrary to programs designed for specific mining method layouts which can be adjusted in a more or less wide range. PROGRAM DEVELOPMENT The principle correctness and feasibility of the approach was proved by a prototype program. However this program was more on a research level and far away from application for "real world" problems. The reason for this was, that it was regarded wasted time to re-invent certain tools, e.g. geometry intersection, deposit modelling or visualization. Hence it was tried to attract several software producers to invest in finalizing the model. Unfortunately this endeavor was not successful. Despite this defeat - and after some months of resignation - a final start on the project was decided. he reason for this decision was not at last the research activity in respect of low-cost underground mining methods for bulk- material as a substitute of typical quarry operations due to environmental restriction. This research work - which is in particular important for Austrian mining activities in beautiful and touristically used landscape - requires a lot of calculations in the way described. Both are still in state of progress, but - regarding mining method modelling - preliminary results can be presented. A complete re-programming of the program was required. Most obvious are the changes of programming language and operating system environment. Instead of Pascal under DOS C++ under MS-WindowsNT is now used. Several problems could be solved by this, in particular memory management, device drivers for input/output, and user friendlyness by up-to-date windows technology. However also more basic structures were changed. The idea was to utilize as many existing commercially available programs as possible to minimize programming efforts. WindowsNT helps already a lot by MFC technology, but also due to its multi-task facilities. This feature allows to run simultaneously several pro-

Jan 1, 1996

By O. Ogunsola, M. Downing

This paper gives a brief overview of impacts of coal blending on coal-fired power plants performance and discuses the preliminary results of an on-going study aimed at evaluating the effect of coal properties on the effectiveness, compatibility and thermal reactivity of coal blends. Plant survey studies reported no significant impacts on an existing plant designed for a high rank coal when switched to a blend of low- and high- rank coal. However, slight modification of some aspects (handling, fuel storage/stockpile, transportation, preparation, and general housekeeping) of plant design and operation may be necessary. The preliminary results of an on-going study at the Mineral Industry Research Laboratory shows that more compatible and better blends could be made from coals where ranks are closer than from those where ranks are far apart.

Feb 24, 1997

By Jon Bowler

Daw Mill Colliery, UK Coal, near Coventry in England, mines the Warwickshire Thick Seam at 800 m/2500 ft depth using longwall retreat with gateroads supported by rockbolts. Over the last eight years the mine has worked longer and wider panels with extraction heights of over 5 m. Recently the mine has experienced high deformation conditions principally from the rib sides resulting in operational issues and production delays. Investigation of rib deformation was undertaken using new inspection and measurement techniques, including systematic laser surveying, and improved rib support consumables were developed and introduced. A new rib trussing system using textile webbing has proved very successful.. A rib support management system was also developed and introduced for face retreat. This allowed rib support to be more effectively managed both for production and safety. For the current developments, new 28-mm-diameter roof and rib bolt systems have been introduced and rib bolt length has been increased to 3 m, with the aim of achieving gateroad stability over the life of the panel. Significant reductions in roof and rib deformation have been confirmed by the latest monitoring results. These ground control innovations are allowing Daw Mill?s potential to be realised. Production from 302?s face in 2008 set new UK and European records. However the support enhancement process continues and further innovations are planned.

Jan 1, 2009

By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION The investigation of the general hazards of combustible gases and vapors in manholes owned by the Edison Electric Illuminating Co. and the study of methods for eliminating these hazards, conducted by the Bureau of Mines, the Edison Electric Illuminating Co. of Boston, and the Boston Consolidated Gas Co. since 1929, was continued during 1933.From May and through December 1933 these tests were supplemented by a study of the manholes of the New England Telephone & Telegraph Co. The test crew was under the direct supervision of John Campbell, superintendent of the Special Service Department of the Edison Electric Illuminating Co., and F. M. Goodwin, vice president of the Boston Consol¬idated Gas Co.The procedure of sampling manhole atmospheres and of shipping the samples to Pittsburgh was the same as that used heretofore. In previous reports the relative explosibility of the samples was calculated by adding the percentages of the illuminants, hydrogen, carbon monoxide, methane, and ethane, dividing the total by 6.5, and multiplying by 100. Experience has shown that the factor 6.0 is more nearly correct; therefore, this has been used in calculating the relative explosibility of all the samples listed in appendix A and B of this report. If gasoline vapor is present a smaller factor must be used.ACKNOWLEDGMENTSThe cooperative investigation was arranged through the interest and effort of W. C. Bayliss, president of the Edison Electric Illuminating Co. of Boston; W. C. Beckjord, vice president and general manager of the Boston Consolidated Gas Co., and A. C. Fieldner, chief engineer, Experiment Stations Division, United States Bureau of Mines. Thomas H. Haines, superintendent, Distribution Department of the Edison Electric Illuminating Co., cooperated heartily in furnishing both men and information for the work."

Oct 1, 1934

By Michael H. Inglis

The Technology Application Center, in conjunction with the U.S. Bureau of Mines Liaison Program, is studying the use of Landsat data for the monitoring of coal surface mine reclamation activities. Landsat may provide sufficient information to reduce the number of on-site inspections now required. The focus of the project has been the Navajo Coal Mine located in north- western New Mexico and operated by Utah International, Inc. On October 15, 1977, a field team recorded spectral measurements at the mine during the time of Landsat's overpass and a corresponding aerial photographic flight. Training sets were selected from the ground and aircraft data representing vegetated, graded, ungraded and natural environments. A supervised classification of the data was performed by the Stanford University Remote Sensing Laboratory then correlated to aerial photos and mine maps. The results, to date, have been very encouraging.

Jan 1, 1979

By O. Jerez, A. Novoselov, L. Gutiérrez, J. Morales, U. Kelm

"In Chile, the evaluation to reprocess tailings for elements other than the traditional Cu, Mo, Au, and Ag, as well as projects to implement long-term monitoring of mining residue sites are key elements of the government’s roadmap laid out for the mining industry for the next two decades. Characterization routines for tailings and mining residues in general have to be adapted from traditional ore and gangue mineral and micro-chemical studies. This contribution summarizes key aspects for the regional mining industry for a basic characterization of tailings with emphasis on small- to medium-size operations with limited in-house facilities and funds to carry out extensive characterization programs. The oldest tailings in Chile were deposited almost a century ago; this fact gives importance to the recovery of past ore /gangue feed information, process circuits and changes (e.g. acid to alkaline flotation), process water provenance and recovery, meteorological registers, and routines of filling a tailings impoundment. Basic characterization should include X-ray fluorescence spectrometry combined with laser diffraction (LD) granulometry followed by X-ray diffraction (XRD), optical microscopy (OM) and automated mineral analysis (AMA) on a reduced set of samples identified by hierarchical cluster analysis. For this detailed stage, only coarse tailings are recommended for direct a study by microscopy and automated mineralogy (P80 >100 µm); for fine tailings (P80 ~30 µm) a combination of XRD and deposit type adapted sequential extraction are more informative options. In particular, for XRD of clay phases, losses of crystallinity may result in deviation of spectra from standard reference phases due to prolonged storage. To monitor surface alteration, scanning electron microscopy can be complemented by Raman spectroscopy to detect residual reagents on mineral surfaces. For reactivity modeling BET measurements are essential."

Jan 1, 2018

By Eduard Stefanescu, James M. Mwase, Egon Sehner, Stoyan Gaydardzhiev

"The study is focused on investigating the production of synthetic rutile of 95% purity or higher from a Norwegian ilmenite ore concentrate. This was to be achieved using a sequential process involving oxidative-reductive roasting at 975°C, followed by magnetic separation to further concentrate the sample and finally leaching with 20% HCl to remove mostly Fe-based impurities leaving behind synthetic rutile. The key process parameters considered were roasting time (1 and 2 hrs), leaching temperature (100, 125 and 145°C), pulp density (15 and 25wt%) and leaching time (3 and 6 hrs). The option of directly leaching the concentrate without pre-treatment was also evaluated. Test work was conducted using samples screened to a size fraction of 105-212 µm. Samples were leached in a 1 L glass autoclave. The reactor was hermetically sealed and thus the resulting pressure was not controlled but was dependent on the process temperature. The product from leaching was calcined and analysed via XRD and SEM to determine the purity of the product. The magnetic separation step was found to be ineffective and discontinued early in the study. Thus far a product with 97% synthetic rutile purity as analysed by SEM has been produced by directly leaching the concentrate at a temperature of 145°C, pulp density of 25wt% and leaching time of 6 hrs.INTRODUCTION The study investigates the use of a process route comprising oxidative-reductive roasting, followed by magnetic separation and then hydrochloric acid leaching and calcination to produce synthetic rutile from ilmenite concentrate. The grade of synthetic rutile produced should be suitable for chlorination to produce pigment grade TiO2. Hence the proposed process should produce a product consisting of no less than 95% synthetic rutile. Additionally, the product should have no more than 1.5wt% combined content of CaO and MgO (Zhang et al., 2011) as they tend to form high-boiling-point chloride leading to the malfunctioning of fluidized bed chlorinator (Cardarelli, 2008). Finally the product should have no more than 2.1wt% of Fe2O3."

Jan 1, 2018

By M. Beth McClenaghan

This paper summarizes diamond exploration techniques used in glaciated terrain, focusing on indicator mineral and geochemical methods applied to glacial sediments. Understanding the ice flow history, depositional history, and stratigraphy of glacial sediments are essential to successful sampling, interpretation and follow-up of indicator mineral and geochemical anomalies related to kimberlites. Kimberlite indicator minerals survive glacial transport over long distances and the relative abundance of each mineral in till is a function of the primary mineralogy of individual kimberlites. Indicator mineral distributions observed at a regional scale define the net effect of glacial dispersal, often along different ice flow directions. Local-scale distributions define individual dispersal trains. The medium sand (0.25 to 0.5 mm) fraction of heavy mineral concentrates prepared from glacial sediment samples is best suited for indicator mineral surveys. The application of till geochemistry to diamond exploration is increasing because it is significantly cheaper than indicator mineral analysis and it can be performed quickly. The <0.063 mm (silt+clay) and 0.5 to 2.0 mm (coarse sand) fractions provide the best geochemical contrast between background and kimberlite-rich till. Kimberlite pathfinder elements that provide good contrast include Ni, Cr, Ba, Co, Sr, Rb, Nb, Mg, Ta, Ca, Fe, K, Ti and REE, the relative importance of which will depend on kimberlite composition as well as that of the surrounding bedrock.

May 1, 2002