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By G. J. de Korte

South Africa’s best-quality coal, located in the central Highveld basin, is becoming depleted and alternative sources of coal, such as the Waterberg coalfield, will have to be developed to supply the country with coal in the future. The quality of the coal being mined in the central basin is gradually becoming poorer. This necessitates that more of the coal be processed to improve the quality to meet customer requirements. The challenge to the coal processing industry is to process low-yielding coals to produce goodquality products and at the same time ensure that coal mining remains economically viable. This requires that more cost-effective coal processing technologies be investigated and implemented.

Jan 1, 2015

By Jack Zhang, Yunguo Tang, Baodong Zhao

"Rare earth elements (REEs) have numerous key applications in both traditional and advanced technologies. A shortage of some critical REEs is expected due to the discrepancy between the REE abundance in REE deposits and the REE demand from the market. For example, Neodymium, Europium, Terbium, Dysprosium, Erbium and Yttrium are expected to be in short supply. REE recovery and separation from secondary resources such as uranium wastes, heavy mineral sands, and recycled materials can balance the shortfall in a cost effective way.The Saskatchewan Research Council (SRC) is engaged in the development and commercialization of complete REE recovery and separation technologies in Canada. One of SRC’s newest developments is the design and commissioning of a heavy rare earth (HREE) separation pilot plant. The pilot plant uses hundreds of stages of solvent extraction (SX) to produce high purity individual HREEs from both primary and secondary resources.This paper presents the design of an HREE recovery process for the particular case of uranium processing wastes. The separation results of a group separation are reported and discussed, as well as the issues and the challenges of the development, commissioning and operation of the continuous SX pilot plant.IntroductionSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are found in uranium wastes in Saskatchewan. It estimated that about 47 tonne/a of heavy rare earth element oxides (HREO) including 27 tonne/a of Y2O3, plus 6 tonne/a of Sc2O3 are in the raffinate of every uranium mill for potential recovery. Since the HREEs are already in the raffinate, cost effective HREE production is promising in Saskatchewan.Selective precipitation including nutraulization, oxalate and double-salts precipitation, as well as sulfide precipitation, ion exchange (IX) and SX are commonly used technologies for the recovery and purification of REE solution. REE oxalate precipitation is an effective technology to remove Fe, Al, Ca, Si and other impurities by taking the advantages of the solubility difference between oxalates of REEs and impurities in acidic solution (Xu, 2005)."

Jan 1, 2017

By P M. Hancock, Associates

Lacustrine sediments, hydrothermal explosion breccias and spring precipitates deposited 5200 - 1800 years BP as a result of geothermal activity at Lake Rotokaua, contain New Zealand's largest known sulphur reserves. Current drill indicated reserves are 2 600 000 tonnes of elemental sulphur, assuming a ten per cent (dry basis) cut-off, contained in some 17 000 000 tonnes of ore with an average grade of 214.0 per cent (dry basis) sulphur. Additional inferred ore containing 500 000 - 900 000 tonnes of sulphur has yet to be prospected by drilling. Geological factors will be important in exploitation of the deposit, particularly the extent and disposition of the orebody, sulphur grades and distribution, physical characteristics of the ore, permeability and stability of the overburden and the nature and extent of geothermal activity in the area. Trials to date indicate that Frasch mining and possibly opencutting are unlikely to be successful mining methods. Further mining feasibility studies will be required to ascertain the most likely mining system for the deposit.

Jan 1, 1984

By Clyde L. Holmberg, Paul Zinner

"INTRODUCTION In view of the large tonnage of low-grade iron ore and iron-bearing material known to exist at the western limits of the Gogebic range, the Bureau of Mines undertook an investigation of the area for the purpose of evaluating the iron-bearing formations as sources of iron for possible future utilization.After 6o years of exploration an, development on the Gogebic range, the area investigated by the Bureau represents the known western limit of direct-shipping ore mined from operations on the Gogebic range.An area about 2 miles in length between the villages of Pence and Iron Bolt in Iron County, Vic., was selected for investigation, and trenches wore excavated through the overburden and fully across the iron-bearing formation to obtain 108 bulk samples for beneficiation tests. Exhaustive tests involving gravity and flotation methods, magnetic separation, and magnetizing roasts followed by magnetic separation were conducted on the samples to determine the ammability of the individual formations and the entire iron-bearing zone to beneficiation.Empirical data on the character and mineral content of the formations arc tabulated herein, as well as the results of the beneficiation tests."

Dec 1, 1947

By J J. Batchelor, J B. Metson

Titanium (ilmenite) concentrate was extracted from a New Zealandilmeno-magnetite deposit. Tailings from the existing processing line at the Waikato North Head ironsand concentration plant were used as a raw material feed. The titanium bearing mineral extracted was defined as intergrowths of ilmenite and hematite in the size range below 150 um. The Owen-Honda equation was used to determine the conditions forilmenite/hematite magnetic separation. Three distinct regions of magnetic field strength for the mineral separation have been defined. Theoretical estimates from this calculation have been confirmed experimentally. Ilmenite concentrate was obtained using medium field magnetic andelectrostatic separation. The final material contains 40.6 - 42 per cent TiO2 and 39.1 - 39.8 per cent Fe (total). The actual yield from extraction was about seven per cent of the Zircon, leucoxene and monazite were found as byproducts of thetitanium concentration process. Preliminary experiments have shown the viability of industrial zircon benefication.

Jan 1, 2000

By Reid K. J, Restarick C. J

The breakage and flow characteristics of quartz, ground as a minor constituent with calcite in a continuous wet ball mill, have been determined by carefully controlled grinding tests.A mathematical model, combining the simple functions which describe these characteristics, has been used to predict both steady state and non steady state results.The calculated results are compared with experimental data.

Jan 1, 1966

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 FOSTER HEWElT

THE scope of this paper is the description of two districts in Peru in which deposits of vanadium have been found, and the consideration of much laboratory-work that I and others have done to determine the nature of these deposits. It is with regret that I present some of the data in a state of evident incompletion, particularly the analyses of a few of the minerals, which leaves some doubt as to whether the true nature of the minerals is understood. I make no apology, however, since in this case, as in many others referring to ore-deposits, conclusive opinions cannot be stated until a great amount of work has been done, and the deposit has been thoroughly exploited. I believe that the data and the tentative conclusions here presented indicate a unique and interesting condition which may assist others in work along similar lines; and further, what is of more practical importance, stimulate a search for a metal which, though long considered rare, is probably so merely because proper care has not been taken to recognize it. An excellent bibliography on the occurrence of vanadium in nature is given by F. W. Clarke in his paper, Data of Geo-chemistry;1 and in the preparation of this paper I have consulted many of the references contained in the Bibliography of the Chemistry of Vanadium, by M. Moissan.2 A brief review of the subject having special reference to the metallurgy of vanadium is contained in the small book by P.. Nicolardot.3 One of these vanadium-deposits has already been briefly

Mar 1, 1909

Operating well designed and maintained surface mine haul roads is the key to minimising truck haulage costs - in itself a significant component of the total cost per tonne mined. Existing and proposed mining operations are subject to scrutiny, both from the economic and environmental perspectives. In the long run, this scrutiny returns improved efficiencies and leaner, 'greener' operations. The focus of this evolving evaluation process should and will certainly fall on haulage operations - simply by virtue of their contribution to overall cost of operations and sustainability impacts. Whilst the end result - improved efficiency and contributions to resource sustainability - is not in itself problematic, it is the route, or process followed to achieve these improvements that needs to be carefully managed. We can be guided on this journey by our understanding of how a road is designed, and, critically, the technological solutions that can contribute to a company's sustainability initiatives. This paper examines the current state of mine road design and operation, together with the economic and environmental issues associated with under-performance. The paper serves as a basis for evaluating the economic and environmental contributions that technology in road design and management can deliver to sustainable operations. Utilising innovation is the key to long-term sustainability and as a means of positioning the industry for the imminent structural changes to the economy and environment, changes which are now within the operating life of many mines, haul roads and haul trucks.

Jun 1, 2010

By Wilbert T. Malenka

A modified factorial experiment was used to determine the effect of operating factors in hydraulic mining of anthracite. Seven basic factors at various levels were considered. The significant factors were found to be pressure-volume, pattern, and jet traverse speed. Mining data were programed for computer, and a prediction equation was determined from printout information based on the hydraulic "jumbo" operating parameters and characteristics of anthracite, The source of error is discussed. The prediction equation is general in nature and might be useful in delineating performance characteristics in the design of equipment and/or more effective utilization in a medium with characteristics similar to those of anthracite.

Jan 1, 1968

By A. Wahab Khair

Coal mining has evolved into extensive use of continuous mining machines for development and production. This has resulted in an increase in dependence on the versatile continuous miners. The present-day continuous miners are powerful in terms of rated power but are still plagued by wear of bits which hinders development and production as the bits have to be continuously changed at regular intervals. Previous attempts to analyze bit wear has been either restricted to the theoretical approach and or laboratory testing. This paper discusses about the overall aspect of bit and drum design for different conditions. Using the laboratory model set up, numerical models and field testing, a new bit and drum design was analyzed to evaluate their performance under different conditions. The results proved that a newer bit design and drum design were successful in limiting the amount of wear as well as improving the performance of the continuous miner and production.

Jan 1, 2008

By Padmavathi V, M. Najamuddin, M. R. Madhav

Granular piles are one of the leading ground improvement techniques, adopted for the betterment of bearing capacity and reduction in settlements of the foundations and also to accelerate consolidation of the surrounding soil. In the recent past, there has been extensive research on the settlement analysis and behavior of granular piles under varied soil conditions. The application of these theoretical solutions to practical problems requires a knowledge of representative values of the deformation parameters of the ground and the granular piles. However, very little information is available on these parameters. The paper presents a new method for the estimation of the modular ratio of granular piles and modulus of deformation of the surrounding in-situ soil from the compression load tests. The load - settlement response obtained from the compression test results are used in the back analysis for estimating the modulus of deformation of the ground. The presence of granular bed, under the rigid plate for load testing, has been given due consideration in quantifying the proportion of load transferred on to the stone column. Based on these considerations a new method is developed to estimate the modulus of deformation of the ground and the modular ratio of the granular pile.

Sep 1, 2022

By Leslie C. Richards

Sooner or later the potential miner of industrial minerals reaches the conclusion that of the various factors he must consider, the marketing of his product is. the most important. The sooner he realizes this the better, as successful industrial mineral producers .will confirm. Herein lies a difference between i.ndustria1 mineral mining and metal mining. Often in the latter, technical problems of mining or concentrating are equal to or even surpass those of marketing. This is not meant to imply that there are no problems in mining and beneficiation of industrial minerals, but these usually are outweighed by the problem of marketing. Recentlv. an official of a nationally known corporation :i the elecl.ro-metallurgical industry made an industrial mineral survey in the Pacific Northwest. In the course of his investigation he interviewed producers and potential producers of the various industrial minerals scheduled for use in the plant now being constructed in this area. He stated that he was interested in only three factors: namely, (1) Can your product meet our specifications? (2) Are you able to supply our tonnage requirements? and (3) What will be the delivered price? If there are several sources of supply of sufficient grade and tonnage, as is often the case in the Northwest, then the third factor becomes the important and deciding one. While industrial minerals are usually sold f.0.b. cars with the freight being paid by the buyer, it is the delivered and riot the f.0.b. price that determines the competitive position of the producer and his industrial mineral product. Unfortunately for both the consumers and producers of industrial minerals in the Northwest, the sources are generally a considerable distance from the markets. This necessitates long rail hauls, for which transportation charges make up the largest share of the delivered cost and the delivered price of the product. Is it any wonder then, that rail rates play such an important part in the marketing of industrial minerals? In order to sell his product, the producer must be able to deliver to the market at a competitive price. It must be remembered that his largest cost factor is rail transportation, and that he is limited to markets that he can reach competitively. Since the cost of rail transportation is so important, let us compare various freight rates in the Northwest and attempt to determine their influence on marketing. A study of all rates on all industrial minerals transported in this area, is beyond the scope of this paper. For the purposes of comparison, let us consider limestone (broken, crushed, or ground), and silica rock. These are widely used industrial minerals, and are carried by several different rail routes from.the sources of supply to the centers of consumption in the Pacific Northwest. Markets and Sources of Supply: Limestone has a number of uses in western Oregon and Washington. Among them are agricultural lime for the soils of the Willamette Valley and southwestern Washington; paper rock for the mills in such cities as West Linn, Oregon City, Newberg, St. Helens, and Salem, Oregon, and Camas and Everett, Wash.; chemical and metallurgical-grade limestone for the metallurgical plants centering around Portland, and the Tacoma-Seattle areas'; and sugar rock for the sugar refineries at Toppenish, Wash., and Nyssa, Oregon. Since limestone for cement manufacture is generally processed near the quarry, transportation

Jan 1, 1951

The usefulness of laboratory studies - petrology and mineragraphy in the search for, and investigation of, mineral deposits should not be exaggerated, but it should not be overlooked, because such studies will always contribute to an understanding of the geology of the deposits, and can on occasions provide invaluable information not otherwise available. A few examples furnished by the investigations of the Mineragraphic Section of the Commonwealth Scientific and Industrial Research Organisation will show this.Petrology.In the early stages of the investigation of the King Island scheelite deposit, during the war, when the nature of, the deposit was not understood, a series of samples embodying the exposed rock types was submitted to the Mineragrap;hic Section for petrologicalexamination by the Mineral Resources Survey. It was at once apparent to the petrologist that the King Island scheelite ore was a contact metamorphic deposit, in which a series of argillaceous shales, calcareous shales, impure limestones and limestones had beenintensely metamorphosed. The shales had been converted to finegrained biotite and actinolite hornfels, according to their lime content, and the impure limestones to fine-grained diopside hornfels, garnetdiopside hornfels and garnet hornfels (calc-flint), the garnet being the lime variety grossularite. The limestones, however, after being first converted to marbles, had suffered intense pyrometasomatism, involving substitution of immense quantities ,of silica and' iron for lime and carbonate, and had been converted largely to a coarsegrained garnet rock, in which the garnet was the lime-iron variety, andradite. The silica and iron were derived from the mineralising solutions of the adja,cent ,granite. intrusion, responsible for the contact metamorphism, and were accompanied by tungsten and some molybdenum. The tungsten in the presence of so much mobile lime, was precipitated as schecelite, much of it finegrained and enclosed in or intergrown, with the andradite garnet or the quartz interstitial to the garnet.It was apparent that the King Island scheelite deposit, was a perfect example of selective pyrometallomatic replacement in a bedded contact metamorphic deposit. The bedded nature of the original rocks was preserved, and the scheelite was practically limited to the original limestone beds, 'Which had been so much more susceptible to replacement after recrystallization, than the other sediments. The further geological study of the deposit then resolved itself into the task of mapping the folding and faulting of the deposit, with bore cores to provide the stratigraphic sequence, and establish the number of scheelite-bearing beds.A second example is provided by a petrological investigation of the mineral composition and genesis of the talc deposits of the Gumeracha district of South Austral.ia, which was undertaken at the request of the South Australian ,Mines Department, in conjunctionwith mapping of these deposits. The field geologist mapping the deposits was experiencing some difficulty in interpreting the structure...

Jan 1, 1950

By G. Lyman

The cross-belt sampler is a device that is very widely used even though it has not been ratified by the Standards associations. This paper is concerned with the bias testing of two cross-belt sampler designs against stopped belt samples and a cross-stream cutter at the belt end. The bias analysis is carried out using size distribution as the analyte and conventional t-testing and the Hotelling T squared test, which are compared for their effectiveness. The paper considers the issue of detectable bias and the statistical planning of bias tests.

Jan 1, 2010

By Gunderson C. T

The use of carbide tipped integral drill steels and detachable bits is discussed in relation to the means of drilling or cutting employed. It is stressed that only by correct use can the full value of these tools be realised.Factors affecting carbide quality, the design of shanking steels and the requirements and techniques of brazing in inserts are considered.It is essential that the brazed jointing between carbide and steel be strong but ductile. The methods used for the manufacture of carbide tipped tools are briefly outlined.INTRODUCTIONIn recent years the application of tungsten carbide to various mining tools in the mining industry, has developed to the stage where it is now regarded as an essential item in the production of coal and metal ores. In fact it is claimed that certain mining operations would not be possible if it were not for the benefits obtainable from the characteristic properties of tungsten carbide. The advantages of this hardmetal have, to some extent, influenced manufacturers to revise design specifiations of some machines, while againsome machines have actually been designed with tungsten carbide as their basic medium for operation.In general the applications fall into the following three categories:(a) Drilling hard rock by percussive means.(b) Drilling soft rock and coal by rotary means.(c) Coal cuttingThis paper is concerned with tungsten carbide tools associated with these three activities in Australia, the effectiveness of their application and significant points in their design and manufacture.

Jan 1, 1958

By Prosser A. P

The conditions under which vanadium is rendered insoluble by silica in the alkali-roast process have been investigated starting with both slag and reagent-grade materials. The inert phase is a glass formed slowlyfrom soluble NaV03 produced at lower temperatures. It contains approximately 30 per cent V in a partly reduced state; iron is not a principal component. Some of the vanadium in the inert phase is slowly returned to a soluble form by heating in an oxidizing atmosphere below the temperature at which the glass is formed (750°C). As the reaction leading to the required, soluble form of vanadium is also slow between 600 and 750° optimization and control of the temperature profile and atmosphere in the furnace, and the residence time of the solids, are necessary to ensure high vanadium extraction during subsequent leaching.

Jan 1, 1976

By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

By D. F. Malan

In deep level hard rock mining the rheological behaviour of the rock is important as time-dependent aseismic processes can lead to a stable dissipation of energy thus reducing violent outbursts. Underground closure measurements, observations of time-dependent fracture formation and siesmic data indicate that the rock in deep South African gold mines shows significant time-dependent behaviour. The objective of this work is to quantify the time-dependent rock behaviour for laboratory specimens and underground conditions. Laboratory experiments indicated that lava and quartzite specimens undergo measurable creep strain at stress magnitudes below the failure stress. Quartzite is however prone to more significant creep at lower stress levels. A viscoelastic analysis showed that laboratory creep results can not fully explain the behaviour observed underground. The in situ behaviour is governed mainly by the rheological behaviour of the fracture zone and the resulting time-dependent formation of new fractures. A viscoplastic discontinuity model implemented in a boundary element program is used to simulate this behaviour.

Jan 1, 1997

By A. Visnapuu

Excessive noise and high vibration are inherently associated with equipment used in the mining, extraction, and processing of mineral resources. High vibration degrades structural components, often leading to catastrophic failure and loss of productivity, and excessive noise can result in permanent hearing loss. In order to foster efficient utilization of the Nation's mineral resources and minimize occupational hazards associated with mineral processing, the Bureau of Mines investigated the relationship between the microstructures of carbon and alloy steels and cast irons and their damping capacities (ability to absorb vibration). Researchers measured damping capacity and other properties and investigated the effects of carburizing, spheroidizing, and annealing. The investigators found that in carbon and alloy steels, rounded colonies of fine-grained pearlite in a ferrite matrix correlate well with low damping capacity. Steel microstructures that exhibit sharp-faceted pearlite in ferrite matrix and partially or fully spheroidized cementite in ferrite show considerably higher damping. In cast irons, the lowest damping capacity is associated with nodular graphite microstructure, and the specific damping capacity (SDC) increases as the graphite micro-structure progresses from nodular to compacted to flake. Predominant ferrite in cast irons is also associated with good damping. SDC data are presented for selected carbon and alloy steels and cast irons.

Jan 1, 1987