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By Konstantin Fedotov, Victor Beloborodov, Anatoly Potyomkin

"There are areas in Russia, which cover huge territories and they are north, and Siberia. These difficult to access regions with cold climate are rich in a great number of distant deposits of valuable and rare metals, gold and platinum. The development of such deposits requires highly effective technologies of mineral processing which could be realized in modular and quick-built processing plants.The work presented includes the results of long term research in the development of new technologies of processing of zirconium (in the form of rare mineral Baddeleyite – natural zirconium dioxide) bearing ore of the Kovdor deposit which is located in the Polar region of the Kola peninsular and also in Siberia deposits of of ledge ores of gold."

Jan 1, 2003

By Anastasia Xenaki, Edmundo Laporte, Antonio Nieto, Jesus Castillo Gomez, Oscar Velasquez

It is particularly challenging for the mining industry to create and implement an efficient and adaptable mining innovation model to secure the continuous improvement of processes and products via technology. Human resource departments must play a vital role in shifting the mining culture, enabling these new classes of digitally skilled professionals to manage the mining operations of the future. This paper proposes the implementation of a concept based on the 5S mining innovation model ((a) Nieto, 2019), in a coal mining project in Central Asia, Mongolia. Practical and empirical evidence suggests that the model could serve as a roadmap to developing technologies and methods for the mines of the future.

Feb 1, 2023

By G. Luttrell, S. Keles, M. Eraydin, R. Yoon

The dewatering of fine particles is energy intensive and often requires costly capital expenditures. To address these issues, a series of advanced dewatering technologies have been developed at Virginia Tech. These include novel dewatering aids that enhance the performance of existing filtration equipment and an innovative hyperbaric centrifuge that utilizes both air pressure and centrifugal force for dewatering. The moistures obtained using these processes are 30-50% lower than those obtained using conventional methods. Another dewatering technology, known as the hydrophobic displacement process, can reduce product moistures to a level previously attainable only through the use of thermal dryers. This article presents test results obtained with these various advanced dewatering technologies along with estimates of the power consumption for each process.

Jan 1, 2007

By William E. Young

There are many large rhodonite-bearing veins containing manganese in the Eureka-Animas Forks area of the San Juan Mountains in Colorado. The Sunnyside vein is the largest known vein in the area. As observed on the surface, the vein is mineralized over 8,000 feet and attains a maximum width of 200 feet. The average width of the vein and its branches and ramifications is 58 feet in the area that was mapped in detail. The weighted-average analysis of surface and underground samples from the northeastern extension of the Sunnyside vein is 8 percent manganese. Most other known veins in the area have a similar manganese content. The Hidden Treasure vein lies southeast of the Sunnyside-No Name-Mastadon vein. The weighted average of the analyses of surface and underground samples from this vein is 13 percent manganese. Exposures of the Scotia-Silver Chord vein are visible over a strike length of 4,000 feet on Treasure Mountain. Diamond-drill holes show that the vein contains 10 percent or more manganese to a depth of 400 feet. The vein has an average width of 28 feet. The Independence vein is exposed on the surface for a distance of 600 feet and has an average width of 6 feet. Three cut samples taken across the vein had an average content of 20.7 percent manganese. Sampling of the outcrops of eight veins in the Placer Gulch area also indicates manganese. Numerous other veins cropping out in the surrounding area are similar to the outcrop of the Sunnyside vein system mineralogically and are worth investigating.

Jan 1, 1966

Preparation of MgO Nano-Particles with Magnesite

Sep 13, 2010

By K. Gie Tan, Frank Wright

"Misty Mountain Gold Limited (MGL - TSE VSE, MGLCF - NASDAQ) of Vancouver, owns the Harmony Gold Project located in the Queen Charlotte Islands of British Columbia. The deposit contains a mineable reserve of 2.3 million ounces of gold, at a 1.2 g/t cut-off and an average grade of 2.1 1 g/t Au.Discovered in 1970 and frequently investigated by previous owners, full-scale production has not yet occurred because of the complex metallurgy of the deposit. Recent process studies that were completed in six months at Process Research Associates Ltd. (PRA) of Vancouver resulted in significant improvements to the project viability. The work involved detailed mineral processing studies aimed at achieving a marketable concentrate. An option for bio-oxidation and cyanidation to allow on-site dor6 production was also investigated.The main findings at PRA followed the front-end recovery of finely divided free gold (Au) by gravity concentration. Approximately 20% of Au reported to less than 0.2% of the mass, resulting in a grade exceeding 500g/t Au. The resulting gravity tailing provided a uniform feed for flotation evaluation. The optimization of this step allowed for a reasonable primary grind size of 80% passing (&) 50pm. Efficient slime’s rejection was made possible by flotation at a reduced pulp density, and pre-oxidized sulphides were reactivated with Na,S. The regrinding of the bulk flotation concentrate followed by up to five stages of cleaning resulted in a combined gravity + flotation product of 50g/t Au with 82% recovery in less than 4% of the feed mass.Further studies indicated that the flotation concentrate was amenable also to tank bio-oxidation. At 65% sulphide oxidation the gold recovery improved from less than 70% to 90% by cyanide extraction using CIL (carbon in leach). This compares to less than 45% gold recovery from whole-ore cyanidation in several previous studies. Heap leaching may also be considered for lower grade material. PRA’s methodical approach and consistent results dispelled the uncertainty about predicting the material behavior for the Harmony Property."

Jan 1, 2000

By Peter E. Price

Salt dome hosted metallic sulfide deposits are the product of a complex evolutionary system involving halokinesis, cap rock development and diagenesis, and the generation, migration, and accumulation of basinal brines and hydrocarbons. Hydrocarbons play an important role in: (1) the production of calcite cap rock which hosts some of the metallic sulfide and sulfur concentrations, and (2) the generation of the reduced sulfur available for metallic sulfide precipitation and sulfur formation. Hydrocarbons and related fluids also are involved in the transporta¬tion and remobilization of the metals. Hydrocarbon consumption, in the course of cap rock development and sulfide mineralization at Hockley dome, is estimated to have been 6.4 million barrels of oil or 114 million cubic feet of methane. Mineral textures, including cap-rock banding, sulfide bands in anhydrite, and fine sulfide mineral banding indicate both episodic fluid influx and fluid compositional differences through time. Features such as pyrite "shells" and sphalerite and marcasite hemispheres may have been localized by hydrocarbon droplets and /or bacterial colonies. Marcasite mineralization in shallow strata above and flanking Hockley dome is best developed over the western and southern parts of the dome. This pattern mimics the known distribution of sulfide mineralization, which is dominantly marcasite, in the underlying cap rock. The iron sulfide paragenetic sequence in the sediments is pyritohedral and cubic + pyrithohedral pyrite followed by marcasite which is encrusted by cubic pyrite. Sulfur isotopic averages for the three stages are +20.8, -20.2, and +6.4 per mil, respectively. These values generally coincide with cap rock sulfate (+20 per mil), cap rock hosted metallic sulfides (-20 to +4 per mil), and sulfur in hydrocarbons (+5.8 per mil). Hydrocarbon compositions indicate provincial variations in oil composition and generation history. Long Point and Boling domes, which have an intergrown sulfide-sulfate-sulfur mineral assemblage indicative of mixed reducing-oxidizing environment, contain oils that are less mature than Hockley dome which appears to be more mineralogically segregated. Sterane biomarker compositions of the oils at Hockley, Long Point and Boling domes indicate a local, dominantly terrestrial source. An oil sample from supracap sandstones on the northeast flank of Hockley dome contained over 750 ppm combined Fe, Zn, Pb, and Co, indicating that hydrocarbons are carrying or remobilizing metals. Cap rock calcite and anhydrite also exhibit provincial variations in strontium isotopic ratios. Calcite and anhydrite cap rocks from several sulfide mineralized domes in the Houston diapir province have strontium isotopic ratios that are more radiogenic than Jurassic sea water (>0.7078). A calcite sample within massive sulfides at Winnfield dome also has a high 87Sr/86Sr ratio (0.7085). Variations in strontium isotopic ratios with strontium content indicate the mixing of at least three Sr-bearing fluids in the cap rock environment, one of which may have been the metal carrier. Anhydrite residues from diapiric salt have strontium ratios up to 0.7100, considerably more radiogenic than Jurassic seawater. These high ratios indicate either that salt and anhydrite recrystallized sometime post-Jurassic in the presence of a fluid with a high 87Sr/86Sr ratio, or that they precipitated in the Jurassic from a fluid with a higher 87Sr/86Sr ratio than Jurassic seawater. Salt domes with cap rocks containing metallic sulfides have only been found in basins that have geopressured zones. Waters from geopressured zones in the vicinity of mineralized salt domes have salinities that are two or more times higher and iron and base metal concentrations that are three to one thousand times higher, than geopressured fluids from other parts of the basin.

Jan 1, 2013

By Charles Steed

The design of pillars in room and pillar operations is always a compromise between factor of safety and ore recovery. In actively mined and accessed areas the stability of pillars must be sufficient to support the roof, providing safe working conditions for men and equipment, while optimizing ore recovery. As a reserve is mined out, and if conditions are favourable, pillars are often removed to increase recovery. Considerations for pillar removal include value of the ore, the effect on immediate and overall mine stability and the safety of the mining operations as well as the consequence of disruption of overlying strata and surface infrastructure as the support of the pillars are removed. Many parameters influence pillar strength and the contribution of the pillar to ground support. These include seam height, seam depth, seam inclination, room span, quality of rock, time, etc.. Empirical, analytical and numerical modeling methods are commonly used to optimize pillar sizing and placement and predict influence of pillar extraction or reduction on ground stability. Practical examples for pillar design and optimization in low seam gypsum mining operations and optimizing sequencing of pillar extraction in thick seam metal mining operations are outlined.

Jan 1, 2003

As part of the Bureau of Mines program for conserving domestic mineral resources, a survey was made of the methods used for identifying scrap metals. Because of the large number of alloys currently being scrapped, correct identification of these materials is essential if they are to be recycled effectively. The methods and instruments used to identify scrap metals are described and evaluated. These include object recognition, color, density, magnetic testing, spark testing, chemical spot testing, thermoelectric measurements, eddy current measurements, and elemental analysis by chemical and instrumental methods. Other potential techniques are discussed also.

Jan 1, 1982

By K. Mondal

A macroscopic approach integrated with microscopic analyses for wettability characterization is presented. Wetting depends on 1) Contact between the dust and the fluid droplets, 2) Wettability of the particles by the wetting fluid, and 3) Wettability rate (due to low contact times). The goal of this paper is to show that the wetting rate is a significant factor in dust control. Samples from the roof, three different horizons of the coal seam and the floor were pulverized to less than 25 µm. Experiments were conducted with known wetting fluids to correlate surface tension and equilibrium wettability. Further analyses were performed in terms of surface charge (zeta potential), particle size, mineral composition, elemental composition, and quartz content. The surface tension reduction was also achieved by the use of chemicals and/or altering the temperature of the water. Two methods were used to evaluate wettability rates: a) near real-time comparison of wettability rates, and b) comprehensive evaluation of the intrinsic wettability rates. The data obtained provides meaningful insights towards the design of engineering controls for an economical solution to dust control in coal mines.

Jan 1, 2012

By Marius B. Wechsler

There are considered deep piles which are fixed in blocks of rotating machinery foundations. A mathematical background is developed for determining the behavior of this kind of piles for motions caused by horizontal and vertical oscillations, as well as by roc-king and twisting. It is assumed that the piles come across a top soil layer of depth c, not capable of lateral support, and penetrate over a length b, in a bottom firm soil layer, or in a bottom soft soil layer in which vibrations can produce voids around the piles. With respect to b and c, as well as to the elastic properties of piles and soils, the analysis leads to the maximum bending moments and shear forces subjecting the piles, to the maximum lateral bearing on the bottom soil layer, as well as to the deflection of the pile and the displacement of the foundation block. The results of the performed analysis can be applied to seismic loads too, and they are illustrated by a numerical example.

Jan 1, 1987

By D R. Peacor, J L. Mauk

Dioctahedral clay minerals in the volcanic-hosted Golden Cross epithermal Au deposit, New Zealand, have been investigated by petrography, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy/analytical electron microscopy (TEM/AEM) to determine the nature of these minerals in a hydrothermal ore deposit. Heterogeneity in the distribution of dioctahedral clays is observed from the hand-specimen scale to the TEM scale, indicating that primary rock textures and fluid pathways (related to rock type, porosity/permeability and fluid/rock ratios), in addition to temperature, are important factors controlling the distribution. As the proportion of illite in mixed-layer illite/smectite (I/S) decreases, TEM observations show decreasing layer stacking order, parallelism of packets, and packet size, and increasing apparent porosity. AEM structural data show a corresponding decrease in AlIV, AlVI, and K+, and an increase in Si, Ca2+, and Fetotal. The observations of this study indicate that local dioctahedral clay mineral reaction progress is controlled mainly by permeability and structure, but that this is superimposed on a predictable, system-wide clay mineral distribution that is controlled by temperature and fluid/rock ratio.

Jan 1, 1999

By T. B. Armstrong

"The developing world energy crisis and spiraling fuel costs have created a new public awareness and general acceptance of the need for energy conservation.Plants will have different objectives for an energy conservation program but there appears to be a common approach on how to save electrical energy.Data for a 180tph Rod Mill powered by a 750 hp motor will be used to demonstrate the relationship of energy input and production levels and to seek an optimum operating condition.Energy Conservation:Plants that have examined ways of dealing with the energy situations have concluded that energy conservation has important benefits for industry, including reduced costs, fewer production slowdowns inthe event of fuel shortages and a continued competitive position.There have been some ""startling"" conservation achievements attained through such simple plant maintenance and operating practices as reducing unnecessary lighting in buildings and yards, turning off' equipment not needed at night or over week-ends, through planning maintenance and production schedules to minimize energy use and through improving quality control to eliminate waste.Significant reducti.ons in energy use have been achieved by some rather simple but vigorous maintenance and plant engineering efforts directed at finding and fixing energy ""leaks"" rather than technological advances or major rework or redesign of facilities and equipment.An Energy Conservation Program often must overcome such obstacles as historic operating practices and emp1-oyee indifference, i.e. the ris.ing costs of fuel should result in re-examination of so1ne basic attitudes to energy conservation. Some measures, rejected in the past largely on the grounds of capj.tal. expenditure, now make economic sense in the light of future escalating energy costs."

Jan 1, 1978

By Richard E. Danell

"Blasting is a principal step in the surface mining process for breaking and, in the case of overburdencasting, moving rocks and minerals. As many surface mines are coming to the end of theiroperational life, blasting can once again play an important role through the earthmoving operationsrequired to rehabilitate the minesite. Since blasting is such an energetic and destructive process, itis difficult initially to envisage its use in rehabilitation. However, blasting has found applications inmany civil engineering projects aimed at rehabilitation, including well digging, channelling and soilcompaction. For surface mine rehabilitation, the main purpose of earthmoving operations is toproduce a stable landfonn that will sustain revegetation. In particular, blasting can be applied toreducing the slope of steep walls left by quarrying and open pit mining through a modified form ofthe overburden casting technique. Blasting can also be applied to breaking up pit floors andbenches to speed and improve revegetation of these areas (subsoiling)."

Jan 1, 1994

By G P. Taylor

Mining Lease SML 57 was registered to Mount Kasi on 5 January, 1995. The Mount Kasi gold mine is located in Vanua Levu, Fiji's second largest island and operated from 1932 to 1946 producing 261,000t of ore at an average grade of 7.5g/t Au. The deposit represents a structurally controlled style of high sulphidation copper gold mineralisation with peripheral low sulphidation mesothermal vein type gold mineralisation. The resource consists of 1,048,000 tonnes of residual soils (eluvium) containing 1.9 g/t Au at 0.5 g/t Au cut off and 1,240,000 tonnes of hard rock at 3.0 g/t Au and 1.0 g/t Au cut. 94 drill holes, 298 auger holes and 85 pits were modelled to outline the resource. 29% of the pits bottomed in mineralisation and it is likely the full thickness of eluvium has been understated. The pit is scheduled to produce 500,000 tonnes of ore per annum to yield 35,000 ounces of gold with an initial 2 years of eluvial ore followed by a further 2 years of hard rock ore. Total capital costs are estimated to be less than 10.0 million dollars with construction planned to commence in 1995. The likelihood of locating further ore is high.

Jan 1, 1995

By A. C. Wilson

In 1991, local prospector C. ?Mickey? Clement recovered at least three alluvial diamonds from the Michipicoten River. Two of these stones were sent to the Department of Mineralogy, Royal Ontario Museum, where they were identified as industrial grade diamonds with weights of 1.05 and 1.13 carats. Both stones were described as frosted and graphite-inclusion riddled. In 1995, prospector Sandor Surmacz and geologist Marcelle Hauseux discovered diamonds in bedrock approximately 20 km north of the Michipicoten River. An 18.1-kg bulk sample of a xenolith-rich lamprophyre, taken from an outcrop at the side of the Trans Canada Highway north of Wawa, yielded 1 macro diamond and 5 micro diamonds. All but one was gem quality (Sage 2000). Since then, more than 36 occurrences of diamonds in bedrock have been reported in an approximately 30 km2 area centred 20 km north of the town of Wawa. The occurrences are hosted within a sequence of unusual, Archean-aged, heterolithic breccias previously considered to have no economic significance. Ten kimberlite occurrences also have been confirmed in the Michipicoten greenstone belt in the last 5 years. Two of these kimberlites are diamondiferous. To date, expenditures on property acquisition and diamond exploration in the Wawa are estimated at $120 million (CAN). This paper summarizes the geological observations made on these occurrences and discusses including the relationship between the occurrences and the regional geology.

May 1, 2003

By Axel Preusse

Mining subsidence plays an increasing important role in the Chinese hard coal mining. Reasons for this are a substantial rise of production during the last decade, a dense settlement in many mining regions, the increasing emergence of private residential property as well as a grown environmental awareness. German companies and research institutions hold an over more than 150 years existing know-how in all subjects of mining subsidence engineering. Due to partially comparable preconditions regarding mining depth, mining methods and geological conditions, a close co-operation between German and Chinese mining subsidence engineering experts has been in existence for some years. This German-chinese co-operation is introduced in this paper.

Jan 1, 2007

By D. Peatfield

The design and operation of coal preparation plants are governed by the inherent quality of the raw coal to be processed, market specifications and the saleable tonnage requirements. Topography influences the layout of the plant but does not affect the process design. The coal market comprises many sectors, each having specific requirements with respect to both size and quality. In turn, these have led to different levels of preparation and the development of specific types of coal preparation plant design. Developments in processing techniques and processing equipment have also influenced the design and now give the preparation engineer numerous permutations in process and equipment selection. This paper gives an overview of the coal industry in general and summarizes some of the developments in the design of plants and technical developments in the areas of dense medium processing, fine coal treatment and equipment design.

Jan 1, 2003

By R. E. Barbosa

Seepage forces generated during tunnel excavation affect the ground response and may cause severe instability problems, including total ground collapse and flooding into the tunnel. This paper presents a new closed-form analytical solution, for stresses and displacements around a cylindrical tunnel excavated in a porous water-bearing elasto-plastic material, which includes the effects of seepage forces. The analysis is carried out in terms of effective stresses and pore water pressures. The solution shows that seepage forces may have a major effect on the effective stresses around the tunnel, on the extent of the plastic zone, on the radial displacements, and on the tunnel support requirements. The conditions for development of a ?flowing ground? condition at the tunnel face have been identified. The paper presents a procedure for the hydromechanical ground-support interaction analysis, to determine the excavation induced inflow and the pressures acting on the lining, throughout the progressive driving of the tunnel, including the effective pressures exerted by the ground and the pressures generated by the water.

May 1, 2009

Uranium ore at Sleisbeck, N.T., occurs as lenticular bodies associated with zones of bleached carbonized schists lying between walls of closely folded quartzite. The ore consists mainly of uranium micas with Borne pitchblende.INTRODUCTIONThe Sleisbeck uranium prospect is about 70 miles E. of Pine Creek, and 160 miles S.E. of Darwin (Fig. 1). The prospect consists of a well-defined, E.-W. trending line of hills, about I! miles long. The line is composed of 3 major hills called the Eastern, Central and Western hills, with minor interconnecting hills and outcrops (Fig. 2).

Jan 1, 1955