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By T. H. Jeffers

The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials for removing metal contaminants from waste waters. The beads, designated as BID-FIX beads, are prepared by blending biomass, such as sphagnum peat moss or algae, into a polymer solution and spraying the mixture into water. Laboratory studies were conducted to determine bead sorption and elution characteristics. Batch and continuous tests demonstrated that BIO-FIX beads sorbed arsenic, cadmium, lead, and other toxic metals from acid mine drainage waters collected from several sites. Selectivity for heavy and toxic metal ions over calcium and magnesium was demonstrated. The beads exhibited excellent metal sorption and handling characteristics in stirred tanks, column contactors, and a low-maintenance passive system. The sorption process was reversible, and metal ions were eluted from the beads using dilute mineral acids. Cyclic tests indicated that the beads continued to extract metal ions after repeated loading-elution cycles.

Jan 1, 1991

Our ultimate resources come from the Sun and the Earth System. At this time we face a world crisis in energy, water and soil resources. Global pollution problems are increasing in almost all nations. There is an urgent need to use our vast knowledge with a new wisdom and this requires new integrated teams of experts to provide the best alternatives for the needed new development problems. These teams must include economists, engineers and a broad spectrum of scientists. Today it is possible to produce clean energy, stop soil erosion, clean water and reduce and use wastes of many types.   There is a great need to improve science, natural science, education at all levels. All people must know how our planet works and that fluctuations, some inevitable, some controllable, are inevitable and that we must prepare for them. And it is clear that protecting the environment, eliminating pollution, preserving bio diversity is good economics. Ecology Economy cannot be separated.  

Jan 1, 1995

Ammonium nitrate-fuel oil (ANFO) explosives are unstable in hot, reactive sulphide-rich ground at Mount Isa. Under certain conditions associated with background heat, moisture, and chemical impurities from natural oxidation, ANFO composites in contact with hot ground disproportionate and the ammonium nitrate can undergo rapid exothermic reactions with sulphide.Reactions can occur in confined charges from prolonged contact with reactive sulphides, or by contamination with sulphide in loading. Partial interaction can result in misfires or premature detonation. Spilt, scattered and unpropagated explosive will undergo further reaction in sulphide-rich environments. ANFO-sulphide interaction is invariably exothermic and causes an irreversible chemical transformation of the ore.The heat generated during reaction may be dissipated, heating the environment, or rapidly accumulated to yield hot spots or areas in excess of 400°C. These can result in forced ignition of bulk sulphide and sustained combustion.Thermal analysis was used to define the critical conditions for ANFO-sulphide interaction and sulphide combustion.The occurrence of incandescent ore is attributed to the thermal interaction between exothermic hydrolysis oxidation, ANFO-sulphide, and combustion processes.Chemical agents and control methods have been developed to prevent ANFO-induced oxidation and combustion.

Jan 1, 1968

By None None

Life as a mining/mineral professional doesn’t leave much time for perusing 20-page technical papers. Yet, being technologically savvy is part and parcel of a successful career in this industry. What’s an intelligent, well-informed person to do?

By Carl Bertrand, Patrice Nadeau, Claude Bazin

"Rio Tinto Fer et Titane processes the ore extracted from the Lac Tio orebody to concentrate the hemo-ilmenite (FeO.TiO2-Fe2O3) mineral that is subsequently smelted to produce pig iron and titanium oxide slag. The ore is crushed, heat treated (roasted) and concentrated using dry magnetic separators. This paper describes a model to predict the magnetic susceptibility of the roasted ore and its behaviour in the magnetic separation plant. The model uses a classification of the ore as a function of the size and magnetic susceptibility of the particles. A subsequent division into mineral species allows the simulation of the magnetic separation process. The model is used to assess various operating options when process disturbances occur.INTRODUCTIONOre processing operations consist of ore size reduction followed by the recovery of valuable species in a concentrate that is subsequently sold for its minerals or metal content. The concentration processes are based on the physical and/or chemical properties of the minerals contained in the ore. Flotation is typically used to recover minerals of base metals such as copper, zinc, lead or nickel. Iron ore and other dense minerals are typically concentrated by gravity separation processes. Magnetic separation uses the magnetic properties of the minerals to concentrate magnetite and other minerals, to clean coal concentrate and to recycle ferrosilicon for dense separation processes (Brophy, 1985).Magnetic separators can be divided into low and high intensity separators and high gradient magnetic separators (Gillet, 2008). Most of the low gradient magnetic separators are built as rotary drums that are operated in wet or dry conditions. Dry magnetic drum separators are used by Rio Tinto Fer et Titane in Sorel-Tracy, Canada to concentrate hemo-ilmenite from the ore extracted at the Lac Tio Lake mine near Havre St-Pierre, Canada. The analysis of production data suggests that process improvement could be achieved by identifying key variables for the control of the magnetic separation circuit and/or by modification to the circuit flowsheet. The use of a process model was considered to be an effective approach to conduct a preliminary analysis of the circuit with a view toward process optimization. However, the literature contains few detailed studies dealing with the modelling of magnetic separation processes."

Jan 1, 2011

By G. St. J. Perrott, N. A. Tolch

"The measured strength of an explosive depends to a certain extent on which it is determined. An earlier investigation showed the relative propulsive strength of dynamites as determined in one type of apparatus, ballistic pendulum.4 The aim of this paper is to precept strength data on these same dynamites determined in another type of apparatus, the Trauzl lead block, and to compare the results with those of the ballistic pendulum. Trauzl lead block have been in use many years for the determination of thy strength of explosives, under moderate confinement.5 The common practice is to shoot 10 grams of explosive, in tinfoil wrapper,- and then to measure the volume of the cavity produced by the shot. The volume of the original borehole is deducted from the gross expansion and sometimes a correction is made for the expansion produced by the detonator. Dry sand is used for stemming the charge.It has been found that the expansion in Trauzl blocks is not strictly proportional to the charge. Naoum5 believed that for scientific accuracy the charge should undoubtedly be regulated to give the same average expansion for each sample tested, but for expansions of 200 to 400 cubic, centimeters the deviation from proportionality is not sufficient to give results appreciably in error.Neubner7 found that the proportionality curve is tangent to the charge-expansion curve at about 300 cubic centimeters expansion, provided that no deductions are made for the volume of the original borehole or the effect of the detonator; the total or gross expansion is proportional to the charge between expansions of 250 to 350 cubic centimeters without serious error."

Oct 1, 1930

By Javier Illanes, Maurice Moore, Felipe Moroni, Rafael Acosta

Any organization that subjects its activities to a continuous improvement process must be able to adequately measure the results of the implemented changes in order to pursue better results over time. This is no different for mining companies. When it comes to blasting, an accurate fragmentation analysis can correlate blast design and rock mass parameters to particle size distribution, enabling us to further analyze the correspondence of specific design patterns, applied to specific rock mass properties and the result in measured fragmentation indicators, such as P80 and fines percentage.

Sep 30, 2022

By J. A. Organiscak

This paper examines methods for limiting occupational silica exposures for roof bolting personnel in underground coal mining. A canopy air curtain and an air tube were evaluated as means to provide filtered air over the breathing zone of these personnel. Laboratory testing showed that dust reductions beneath the air curtain and air tube approached 60 percent and 40 percent, respectively, with low interference air velocities. The data also showed that dust reductions were highest for positions closest to the device and that these levels decreased with distance. This paper also evaluates a metal rake, a flexible insert, and a rigid insert for cleaning the roof bolter dust collector box. Less dust was produced when using the rigid insert. Surprisingly, the flexible insert was sometimes no better than scraping or raking the dust onto the mine floor. However, little dust got on the coveralls when using either of the inserts.

By Greenwood J. N

This work was commenced at a time when information on the manufacture of cemented tungsten carbide was urgently needed in Australia. Much information of a general type has been published, but many of the details of the processes used are still undisclosed. The aim of this research was to determine a satisfactory way in which cemented tungsten carbide could, be made, and to investigate the problems which are associated with the process. As the work proceeded, its ramifications grew continually, and it was necessary to limit the possible lines of investigation. After much experimental work, a 9% cobalt-tungsten carbide alloy was developed which had satisfactory properties when used as a cutting tip. The effect of certain variables on the properties of this particular alloy was investigated.The tungsten carbide was prepared in stages from King Island scheelite concentrates under strict laboratory control, whilst the cobalt (1) used was made from cobalt oxide prepared from crude cobalt oxide obtained from Eisdon.In order to clarify the detailed experimental work, a brief summary of the method used for the preparation of cemented tungsten carbide follows.Tungsten carbide and cobalt are prepared in a very finely powdered state, and are then thor,oughly mixed by a ball milling operation. The resultant mixture is pressed in a suitably shaped die into small compacts which are subsequently '''presintered,'' i.e., heated' in hydrogen between 800°C. and 1000°C. The final sintering is carried out in hydrogen between 1,400°C.and 1,600°C. for about half an hour. These "alloys" may contain from 3 to 13% cobalt, depending on the particular properties required of them.PREPARATION OF MATERIALSThe tungsten oxide prepared as described by Smithells (2) was extremely finely divided, and after a few hours' grinding in a ball mill, the powder consisted of material below 10 microns iJ;l size. The oxide was reduced to tungsten metal with hydrogen in a tube furnace. The reduction was carried out at 800-900° C., a rapid flow of hydrogen being maintained in order to remove the water vapour' formed as a result of the reactions:

Jan 1, 1942

A clay binding agent has been investigated to enhance flotation recovery of bitumen from Canadian high fines oil sand in the Clark Hot Water Extraction (CHWE) process. Selective adsorption on fine particles and subsequent agglomeration are critical for the success of clay binder enhanced oil sand flotation. A number of flotation tests have been performed at different reagent dosages under different operating conditions such as pulp pH to evaluate the reagent performance. Dissipative Quartz Crystal Microbalance (QCM-D) analyses of clay binder adsorption on quartz were carried out to better understand process mechanisms. It has been found that use of clay binder in flotation resulted in an absolute bitumen recovery increase of 18%, 25%, and 11% for the high-, medium-, and low-grade oil sand samples, respectively. The QCM-D analyses have revealed that the clay binder was strongly adsorbed on the SiO2 surface.

Jan 1, 2012

By W. G. Freeman

It is unlikely, as In the past, improvement in truck efficiency and capacity can fully offset the effects of inflation, fuel costs/shortages and ever increasing haul distances. There-fore, investigations of haulage systems less sensitive to these problems are warranted. Thus, this U.S.B.M. contract research study on alternative continuous haulage systems was prepared. This study identifies the physical, economic and technological parameters in the application of continuous haulage systems with special attention to under pit slope conveyors and skip hoisting systems. The evaluation data was gathered from extensive literature searches. European/North American mine visits, and industry comments. The study concludes that continuous underground haulage is a viable method within the proper geometric configuration.

Jan 1, 1978

By José Vidalón

Dado que las lagunas de Papacocha y la Virreyna sufren los efectos de los drenajes ácidos de minas abandonadas, relaves y desmontes depositados en sus áreas de influencia, se ha previsto el control de los mismos. En este sentido, el presente texto evalúa los pasivos y propone soluciones dirigidas al control del drenaje ácido contaminado con metales disueltos, priorizando los métodos que no requieren la construcción y operación de una planta ni supervisión permanente.

Sep 13, 2001

The Peelwood district of New South Wales is located some 65 miles south of Bathutst on the Tuena-Crookwell road. A number of occurrences of lead-zinc-copper ore are known from this district but only three mines, Peelwood, Cordillera and Mt. Costigan, have achieved any significant production. The purpose of the paper is to describe the mineral composition of sulphide ores from these three localities.HISTORYNo published information on the geology of the Peelwood area is available. Came (1899) reports that, at the time of cessation of mining operations in 1888, the Peelwood mine had produced some 600 tons of copper metal and regulus, the Cordillera mine had yielded 9000 tons of ore at the recoverable grade of 2·5 per cent Pb, 2·5 per cent Cu, 90z/ton Ag and 1 dwtjto:p. Au, but that no production figures were available from Mt. Costigan. No further work was carried out on these properties until 1951 when the Electrolytic Zinc Company of Australasia instigated a programme of geological mapping and exploratory diamond drilling (Whitten, unpublished data, 1953). The Peelwood district was recently mapped by Mutton (unpublished thesis, 1960) from whom the following geological summary account was taken.GENERAL GEOLOGYAll rocks in the Peelwood area belong to a series of interbedded fine grained sediments and volcanics that are thought...

Jan 1, 1961

By G A. Challis, A B. Christiel

Microprobe analyses of electrum grains in some Hauraki Au-Ag deposits indicate that gold fineness is in the range of 500 - 800 (50 - 80 per cent Au), but for most deposits the range is usually narrower than this. The electrums contain minor amounts (<0.8 per cent) of copper, arsenic, antimony, mercury, iron, and sulphur. Platinum and palladium were analysed for but were not detected (detection limit 0.24 per cent for Pt or Pd). For some deposits (eg Waihi), the average fineness values for the analysed electrums correspond fairly well with the electrum fineness determined by assay during the historic mining operations.

Jan 1, 1992

By J. B. Stott

The performance of an adiabatic calorimeter for measuring heats of oxidation of coal is assessed and suggestions made for its improvement and calibration. The use of magnetic analysers for measuring small oxygen deficiencies in air is described and three different methods of measuring the output for such a meter are characterised. The occurrence of spontaneous heating in an 800 tonne heap of Wyoming coal is briefly described. The major part of the report deals with the oxidation of Pittsburgh seam and Wyoming subbituminous coal and describes an experiment in which 1 tonne of Wyoming coal is stored in a 5 metre long insulated container whilst air was passed through. Temperature rises, rates of oxygen absorption and gas compositions of the air stream were measured. The report relates the results of these-experiments to a theory of spontaneous heating developed by Stott and Quan which stresses the importance of the moisture content of the coal and the relationship between the heat necessary to evaporate this water to the heat available from coal oxidation. The work was carried out over a five month period and the emphasis is on demonstrating the effects of moisture transfer and confirming the theory of Stott and Quan.

Jan 1, 1980

Very little has been written about the discovery and early history of prospecting of ironstone deposits in the Iron Knob-Middleback Range area of South Australia, the main source of supply of ironstone (hematite) for the Australian steel industry, and scanty though the record is, much of it is wrong or misleading.With the help of several people, to whom acknowledgement is made at the end of the paper, the writer has unravelled some of the story, but not the whole story. It is hoped that publication of this paper will stimulate interest in others, who may be able to supplement this account from family records, from the files of newspapers, or from archives.

Jan 1, 1969

By A. Nkolele

Paper written on project work carried out in partial fulfilment of B. Tech (Metallurgical Engineering) degree Fine coal of the Goedehoop Colliery is dewatered by centrifuging before being sold. Full-scale plant tests were carried out to reduce residual cake moisture by the addition of surfactants. It is believed that by modifying the interface between the coal surface and the adherent surface water, as well as the water occluded in the cake voids, drainage is improved. Two anionic surfactants at concentrations up to 150 g/t were tested on coal of <0.5 mm size. The results demonstrate that quite high additions of surfactant (80 g/t)were needed to reduce moisture from 20 to about 17?18%. It was observed that when increasing surfactant additions at low levels, within a very narrow concentration range, the retained moisture first increased sharply only to decrease sharply immediately thereafter; this effect points to a critical surfactant concentration. Based on the obtained results, the use of surfactants cannot be recommended at this stage; further investigations under more controlled conditions are required.

Jan 1, 2004

By W. L. Thayer, K. A. Jonasson, R. D. Coleman, J. D. Hazlett, C. E. Capes

"Loss of coal fines in reject slurries limits the yield of coal cleaning operations. Difficulties in handling fines also limit the extent of physical cleaning in treating coals with finely-disseminated impurities. Selective oil agglomeration allows even extreme fines to be processed and offers some novel approaches for coal cleaning and utilization.The oil agglomeration process for the recovery and beneficiation of fine and ultrafine coal has now been commercialized by the Chemical Engineering Section/Chemistry Division of the National Research Council (NRC). This paper describes these activities to apply oil agglomeration and related fine coal technologies on an industrial scale. Pilot plant and large scale results are described, as well as aspects of agglomerate utilization in both wet and dry form."

Jan 1, 1988

By M. S. Raseroka

An experimental rig has been constructed to produce chloride stress corrosion cracks in Type 304L stainless steel tube samples. The samples are to be used to test possible in situ repair methods in future work. The factor which influences the time to failure most strongly is the sample temperature; the distribution of cracks within the sample is affected by local temperature variations and by the position of the water line. Low-frequency oscillations in stress, caused by the on-off temperature controller, did not appear to influence cracking in these tests.

Jan 1, 2009

By A. H. Mumin, A. K. Somarin, K. S. Oran

"Synvolcanic structures played a fundamental role in the genesis, morphology, and siting of volcanogenic massive sulfide ores and associated hydrothermal alteration in the Archean South Sturgeon Lake caldera complex. The most voluminous and persistent hydrothermal venting and massive sulfide deposition occurred along synvolcanic rifts and grabens associated with faults and tectonic fissures that created permeable fracture zones deep enough to access the underlying hydrothermal reservoir. The type of fracturing is highly variable and changes with the composition, competency, degree of consolidation, and alteration of host rocks. Synvolcanic structures and fracture styles also vary according to the amount and type of tectonic movement, including extension-related collapse, shearing and faulting perpendicular to the principal direction of extension, and orthogonal faulting and shearing. Permeable conduits were created by tension fracturing along fault zones, brittle deformation at the intersections of orthogonal faults, and by extensional fractures in stockworks. In texturally uniform footwall rocks, the distribution of alteration zones was controlled by the morphology of the structural conduit. In rocks with vertical and/or lateral facies, permeability, and competency changes (e.g., Lyon Lake graben), there was an additional stratigraphic control over fluid migration. Some crosscutting synvolcanic structures, alteration zones, and intrusions appear as stratiform units at the present erosion surface due to regional deformation and the present attitude of the volcanic stratigraphy.Hydrothermal mineral assemblages (e.g., quartz, carbonates, chlorite, pyrite, chalcopyrite) infilling structurally induced fractures provide good evidence of fluid migration pathways. However, mineralogy can vary significantly according to the fluid characteristics, host rock geochemistry, and subsequent metamorphic history of the area.Clearly, one of the best methods for locating volcanogenic massive sulfide deposits is to delineate the attitudes of synvolcanic structures, and explore those that show evidence of associated high-temperature hydrothermal mineral assemblages. Excellent exploration targets occur where synvolcanic structures with hydrothermal alteration intersect paleo-seafloor horizons."

Jan 1, 2007