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By K. Esmaieli

This paper addresses issues associated with ore pass degradation caused by material impact. A series of numerical experiments, using the particle flow code, were undertaken to investigate the influence of various finger raise configuration. This has allowed the identification of favorable configurations. The results of this analysis, when coupled with field observations, can contribute to the design of ore pass systems that can prolong the useful operating life of ore pass systems.

May 1, 2009

By Werner Ruegg

El presente texto describe algunos aspectos y propiedades de índole mineralógico, genético e individual de los diferentes yacimientos fosfatados. Existe una diversidad de fosfatos combinados como calcio, fluor, hierro, etc pero están aquellos también que son usados para fertilizantes limitados a los fosfatos cálcicos. De éstos, la apatita es su forma cristalina primaria, constituyéndose como la fuente de combinaciones. La fosforita, a su vez, es su contraparte amorfa, que establece un precipitado químico o un residuo orgánico donde existen combinaciones entre los dos.

Mar 1, 1984

By V. Songmene, A. Tahan, J. P. Michaud

The machining of thin wall parts, often used in the aeronautical industry still creates a number of problems, including panel deformation. Quality and productivity are often affected. This study seeks to determine the optimal conditions for cutting in order to guarantee a competitive fabrication of parts while still maintaining quality and delivery deadlines. The studied model (Spar) is a typical structural part used in the assembly of airplane wings. The main objective of this study was to improve two performance aspects: surface quality finish (quality criteria) and the rate of cutting by stock removal (economic criteria). To achieve this objective, we used an evaluation process of the geometrical error issuing from the machine-tool. We also determined the stability zones of the machine-tool's dynamic system. Finally, a series of high-speed machining tests (finishing cuts) were conducted using an experimental structured approach (16 000 - 24 000 rpm). Profile measures of surface roughness and cycle times registered during trials allowed us to establish optimal cutting conditions. Surface roughness improved as well as cutting by stock removal. Four parameters were taken into consideration: axial depth of cut, chip load, spindle speed, and cutting fluid. Finally, the influence of the type of cutting fluid was evaluated to show that it did not significantly affect machining results.

Jan 1, 2006

This paper describes the results of a laboratory study on the upgrading of Algoma siderite by the amine flotation of silica and silicate gangue. The experiments indicate that a virtually complete removal of silica is possible in a rougher flotation con-ducted in tap water at natural pH, without prior desliming of the ore. Grinding considerably finer than the apparent liberation size is essential for maximum silica rejection. A cationic collector, Aeromine 3037, gave best results when used in combination with a modifier. Of the several modifiers tested, a Dutch potato dextrin, Dextrin 4356, was found to be the most effective. Both iron recovery and the grade of the final iron product are enhanced by floating the pyrite contained in the ore prior to the amine flotation of the silica, and by scalping the magnetics from the silica concentrate. F OR over twenty years, the Algoma Ore Properties Division of The Algoma Steel

Jan 1, 1963

By José Fernandes De Oliveira Ugarte

El presente texto señala los resultados de la caracterización mineralógica de muestras pertenecientes a yacimientos hidrotermales de Lima y así conocer laa mineralogía de de diferentes minerales de plata y sus respectivas asociaciones, así como sus relaciones geoquímicas. Así para evaluar la afinidad de la plata, se realizó el estudio geoquímico estadístico con los minerales alabandita, rodocrosita, pirita, esfalerita, galena, arsenopirita y calcita obtenidos por difracción de rayos X. El contenido de plata se obtuvo con los análisis químicos por fluorescencia de rayos X.

Jun 1, 2013

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By K R. Vining, T E. Norgate

A study was carried out to compare the environmental impacts of the two major iron ore agglomeration processes, sintering and pelletising, using life cycle assessment (LCA) methodology. The following agglomeration processing routes, with the fuel options shown, were investigated:sintering with combined natural gas/coke breeze or charcoal as fuel, grate-kiln pelletising with combined natural gas/coke breeze as fuel, and straight-grate pelletising with combined natural gas/coke breeze as fuel. Inventory data for each process derived from the literature, and in some instances supplemented by additional simulations and calculations, were used in the study and the environmental impact categories considered were gross energy requirement (GER), global warming potential (GWP) and acidification potential (AP). The results of the study showed that the GER, GWP and AP for a sinter plant are higher than those for a pellet plant for the same amount of metallic iron in the agglomerated products. These results are partly due to higher consumption of solid fuel and flux in the sintering process. However, it should be pointed out that the study only compared substantially fluxed sinters with acid pellets that may require additional flux (and hence potentially more greenhouse gases emissions) to be a balanced blast furnace feedstock. Extending the LCA to the blast furnace process stage was beyond the scope of the current study. Within the sinter plant, the sintering stage itself is the largest contributor to the GER, GWP and AP. In the case of pellet plant, the pellet induration stage is the largest contributor to the various environmental impacts. The GER and GWP of a straight-grate pellet plant are marginally higher than those of a grate-kiln pellet plant due to the higher electrical power required by the straight grate system. The substitution of coke breeze with charcoal in the sintering process results in an increase in GER but a decrease in GWP. However, a substantial proportion of the GER is derived from renewable sources (wood), resulting in a decrease in the non-renewable components of this environmental impact. Given the source of the inventory data and the assumptions and approximations made in carrying out the LCAs, it is emphasised that the results presented in this paper should be considered as indicative rather than as definitive results for the two iron ore agglomeration processing routes considered.

Jan 1, 2006

By E. A. Magill

The Bureau of Mines has begun a study of the copper resources of the Cascade Mountains of Washington. The program includes reconnaissance of mineralized areas and examination and occasionally limited exploration of deposits that are considered characteristic of an area. The Bureau of Mines believes that published information may assist industry in searching for new sources of copper. The Miners Queen is one of a few Cascade Mountain deposits selected for prelim¬inary exploration. The investigation was not planned to delineate the ore body. A diamond-drilling program was carried out at the Miners Queen mine in the summer of 1955. Five diamond-drill holes were completed, totaling 628 feet. Two 35-foot shafts were dewatered, and all accessible underground and surface workings were examined.

Jan 1, 1957

By R. Mensah-Biney

The kinetics of gold-bromide loading onto activated carbon has been investigated in a batch stirred reactor. The amount of gold adsorbed by the carbon was correlated with time based on a second-order equation. The rate constant for gold-bromide species onto activated carbon ranged from 0.27 to 1.2 x 10-3 (kg/t)-l(min)-l from a solution containing 25 ppm of Au, with 0.8 g carbon per liter of solution at 30° C. The equilibrium saturation capacity (Q.) was 36±3.0 kg/t from the same system. The rate of loading increased with decreasing particle size, decreasing pH, increasing temperature, and decreasing concentration of gold in solution. The calculated activation energy E. was 8.8 kcal/mole, significantly higher than those reported for physical adsorption. The equilibrium saturation capacity (Q.) increased with increasing concentration of gold in solution, but was independent of other variables such as temperature, agitation speed, particle size and pH. These rate constants and equilibrium saturation capacity for the gold-bromide species are higher than those reported for the gold-cyanide systems.

Jan 1, 1996

By Nadir Ansari, Brian W. Wilson, Marina S. W. Li

"A hybrid Deep Mixing (DM) shoring system was recently constructed for a high-rise development in downtown Vancouver, British Columbia, Canada for the temporary support of a five-level basement excavation. The site is bounded by an existing bridge off-ramp structure along its longest side and by city streets on the other two sides, which formed a truncated triangle in plan. A conventional secant pile wall was installed along the longest side, about 380 ft (116 m) in length, of the site. Hybrid shoring walls (HSW) 1 and 2 were installed along two shorter sides with each being 235 to 246 ft (72 to 75 m) long. HSW 3 completed the excavation support system along the shortest side with a length of about 55 ft (17 m). Cutter soil mixing (CSM) was proposed by the excavation and shoring design-build team in lieu of conventional secant piling. CSM was the preferred method to construct the infill panels between soldier piles because of the speed at which the shoring system could be constructed in the variable fill, peat, wood waste and overburden. Design ConsiderationsTo minimize the impact on buried utilities along the outside perimeter of the excavation, the temporary shoring was designed to limit the lateral displacements to less than 0.8 in (20 mm). Factors taken into consideration for shoring design included the lateral earth pressures from the fill and native soils, groundwater pressures, temporary construction loads (e.g., crane or heavy plant/equipment), and permanent structural requirements. The subsurface conditions at this site typically consisted of fill (cohesive and granular), overlying peat and/or wood waste, overlying clayey silt to sandy silt, overlying weathered to dense to very dense clayey silt till to sandy silt till with silt layers. Localized, perched groundwater was observed within the fill, peat, wood waste and sandy silt layers above the dense till."

Jan 1, 2017

By J Mukhopadhyay, J Gutzmer

Most world-class high-grade (60 - 67 wt per cent Fe) hematite iron ore deposits are the product of enrichment of Precambrian iron-formations but processes responsible for enrichment are still unclear. Different models, ranging from syngenetic and diagenetic (King, 1989), deep-seated hydrothermal (Powell et al, 1999; Barley et al, 1999; Taylor et al, 2001; Gutzmer et al, 2002) and ancient supergene (Morris, 1980; 1985; Van Schalkwyk and Beukes, 1986) to modern supergene (MacLeod, 1966) have been suggested. The high-grade hematite deposits stand in contrast to martiteûgoethite ores which are generally accepted to be the result of supergene enrichment of iron-formation because they are found along Cretaceous to Tertiary lateritic weathering profiles (Morris, 1980; Harmsworth et al, 1990). Uncertainties about the origin of the high-grade hematite ores appear largely due to the monomineralic composition of the ores. They are almost exclusively composed of hematite (as microcrystalline hematite and martite), a mineral with wide stability field and very simple chemical composition that reveals little about its origin. Second, many of the deposits have been overprinted by later deformation and chemical weathering obscuring primary ore characteristics and zonation (Taylor et al, 2001). Third, surprisingly few detailed geological studies have been undertaken on the deposits with the aim of unraveling ore genesis. Most studies focus on the present-day structure of orebodies and their general physical-chemical composition for mining and beneficiation purposes. A more thorough understanding of the origin of high-grade hematite iron ore deposits may be gained by combining available mining-orientated data with systematic petrographic-geochemical analyses of different ore generations and hematite phases. This paper presents a first summary of results of an ongoing study, started some two years ago, of high-grade iron ore deposits in South Africa, India and Brazil, including a comparison with the rather well studied deposits of the Hamersley Province in Australia.

Jan 1, 2002

By S. Mao

Total station has been predominantly applied in stationary survey scenarios in construction. With the moving target tracking and point survey automation functions, a robotic total station (RTS) lends itself well to more dynamic applications. Nevertheless, a RTS unit is still unable to track multiple targets simultaneously or to survey a target point when the line-of-sight is temporarily unavailable. In this paper, we propose a methodology to synchronize and automate multiple RTS units intended to address dynamic tracking and surveying applications in the construction field. By using the application programming interface (API) from the manufacturer, we implement the proposed methodology and the prototype system integrates two RTS units in regard to space and time and communicates survey command instructions among RTS units through wireless networks. The two RTS units can be operated to survey the two ends of one swinging sling concurrently in order to retrieve the actual length of the sling within several millimeters accuracy. Besides, in applications where line-of-sight between a target object and one RTS unit cannot be guaranteed all the time, continuous surveying can be materialized by automatically delegating the task to another synchronized RTS unit with clear view of the target object. A field test was conducted to demonstrate the application of the proposed automation approach in which sling length was measured of a rigging framework used for lifting industrial modules. The testing results are presented and achievable accuracy and reliability are discussed. The proposed solution overcomes the limitations of global positioning system (GPS) and laser scanning and holds high potential to provide cost effective solutions to many dynamic field applications.

Aug 1, 2013

By Gaballah Djona M.

Spent hydrorefining catalysts contain about 5 % of CoO and/or NiO, 12 % of MoO3 and up to 10 % of V205. They are generally supported by alumina and contain up to 25 percent of C, S and hydrocarbons. Such materials are potentially hazardous to the soil and to water resources. Selective chlorination of raw unroasted samples with Cl2 + air gas mixture had been investigated. At temperatures lower than 600 °C, it was possible to recover more than 90 % of nickel and cobalt chlorides, about 99 % of the molybdenum and up to 75 % of vanadium chlorinated compounds. CoCl2 and Ni/Cl2 were extracted from the chlorination residues by their dissolution with acidified water. Molybdenum and vanadium chlorinated compounds were recovered by selective condensation from the vapor phase. The chlorination of Al2O3 could be limited to less than 6 %. The scale up of this treatment was successful and a flow-sheet is proposed.

Jan 1, 1995

By T. Shoji

"The human history is characterized by social development based on mineral and energy resources, and many conflicts to take the resources by power. This is shown by not only world wars but also many local conflicts as well as international supremacy.IntroductionThe world population after B. C. 10000, which is summarized in several papers, is approximated by four straight lines on a semilogarithmic diagram as shown in Figure 1 [l]. The annual rates of increasing are 0.0041, 0.071, 0.53, and 1.85 % from the old and young periods. The boundaries among four periods are approximately B. C. 4600, AD. 1670, and 1930. The start of the second period seems to correspond to the beginning of agriculture and cattle breeding. Precisely speaking, the usage of natural energy resources such as woods and domestic animals already began, but is inferred to have become common after the age. The third and fourth periods are characterized by the common usage of coal and oil, respectivety. Not only energy resources but also mineral resources including gold, copper, iron and others are also important for the human history.Mineral and energy resources have supported the development of the .human civilization, and have caused many conflicts because of this reason. Every day newspapers report conflicts, such as Chechnya, East Timor and Ache. We can easily point out the facts that the conflicts closely relate to mineral and energy resources. Groznyj, Capital of Chechnya, is located on the western margin of Caspian oil field. Many mineral deposits occur in Kavkaz Mountains running south of Chechnya. Subsea oil fields occur in Timor Gap located between East Timor and Australia. Ache is also one of oil fields in Indonesia. It is very difficult to state present conflicts independently of a political view of point. For this reason let us try to historically review the relation between mineral and energy resources and international domination and conflicts [2] based on many papers [3]."

Jan 1, 2000

By Ann C. Kim

This Bureau of Mines report summarizes the methods and results of many of the laboratory studies on spontaneous heating of coal published in the last 50 years. It includes a brief description of experimental methods, indices of combustibility, and important contributing factors. Adiabatic calorimetry, isothermal calorimetry, [0], sorption systems, or temperature differential are the most frequently used experimental methods. Indices of combustibility include various heating rates, crossing point temperature, ignition temperature, and CO index. Factors that affect the spontaneous heating of coal include air flow rate, changes in moisture content, particle size, rank, temperature, pyrite content, geological factors, and mining practice. Experimental conditions and results from 20 papers are summarized in an appendix, and the bibliography contains 45 references.

Jan 1, 1977

An enhanced gravity concentrator was installed in conjunction with an intensive leach reactor at the Sadiola plant in Mali last year and commissioned in December 2007. There has been much debate over the years as to the effect of gravity concentration on overall plant performance. The late Dr Laplante suggested that for every ten per cent of gold recovered by gravity, there was a corresponding 0.1 per cent to one per cent additional overall plant recovery. The results at Sadiola are consistent with this hypothesis with an overall four per cent gain in plant recovery. With total gold recovery of 12 per cent in the gravity section, grades are increased from 3.54 g/t in the gravity feed to an average of 2 600 g/t in the concentrator feed to the inline reactor. The recovery of gold in the inline reactor is in excess of 98.5 per cent. This paper discusses the background to the project, the laboratory test work prior to the equipment selection, the operational results of the system, as well as the benefi ts of the future application of high mass yield centrifugal concentrators in base metals, sulfides and industrial minerals. Bench scale, pilot scale and plant practice examples are also presented.

Aug 1, 2010

By John Paul Gries

During World. War II, when the curtailment of imports led to an unprecedented demand for domestic mica, beryl, spodumene, and other pegmatite minerals, the Bureau of Mines and the Geological Survey entered upon a program designed to expedite mining of these minerals from the Black Hills area of South Dakota. The program involved napping, sampling, and drilling of many pegmatite dikes in the southern portion of the Black Hills and beneficiation conducted in the field and in the Bureau of Mines laboratories at Rapid City, S. Dak., Rolla, Mo., Salt Lake City, Utah, and College Park, Md. This report describes the occurrence and sampling of the Beecher No. 2 pegmatite, which was investigated as part of the general pegmatite study in South Dakota. Investigation of the Beecher No. 2 pegmatite was started on November 20, 1943, and terminated in the spring of 1944. During this period, the Bureau of Mines took a series of trench samples across the pegmatite at the surface for grain-count studies and chemical analyses. The Geological Survey mapped the geology of the deposit after it was exposed by trenching and stripping.

Jan 1, 1950

By Jaeheon Lee, Jae-Chun Lee, Doyun Shin, Minseuk Kim, Hyunsik Park

"The appropriate treatment of cyanide waste water is becoming an emerging issue because of the toxic residue and large quantity produced from gold processing plants. In the present article, we designed and operated a continuous biological cyanide treatment system using domestic sewage sludge and various microorganisms including a cyanide-producing and degrading bacterium, Chromobacterium violaceum. The synthetic wastewater containing 50 mg/L of cyanide was pumped continuously into the reactor at a flow rate of 500 mL/d for 21 days. When 50 mg/L of cyanide was fed, the cyanide concentration in the effluent of the reactor inoculated with activated sludge (S-50) decreased by 7.5 mg/L in the effluent. The other reactors did not show significant cyanide degradation and the reactor inoculated with C. violaceum showed increased cyanide concentration in the effluent. The microbial community in the reactors was analyzed by 16S rRNA-gene based pyrosequencing technique to investigate microbial response to cyanide addition and operation time. The microbial community analysis shows that the phylum Proteobacteria was detected in the reactors showing significant cyanide degradation (S-50), while Firmicutes and Bacteroidetes was dominant in the other reactors with very low cyanide degradation. Proteobacteria could not compete when the other phyla Firmicutes or Bacteroidetes were inoculated. This study shows the feasibility of the biological cyanide treatment system for gold processing plants and contributes new fundamental knowledge about the microbial community in the biological cyanide treatment system. INTRODUCTION Cyanidation has been widely used to recover gold from ores or secondary resources since first proposed by MacArthur and Forrest in 1888 (MacArthur et al., 1888) and it is used in many states of the USA, including Nevada, Arizona, California, Colorado, and Idaho (Laitos, 2012). Cyanide compounds are highly toxic and create serious problems for wildlife and water management (Solomonson, 1981; Donato et al., 2007). Furthermore, because many countries have imposed strict standards for cyanide discharge (USEPA, 1985), it is essential to develop a cost-effective and environmentally friendly technology for treating cyanide-containing wastewater."

Jan 1, 2018

By I. D. Ustinov, V. A. Arsentyev, A. O. Mezenin, A. M. Gerasimov

"The solid mineral raw materials of the sediment deposits containing the argillaceous variations such as the coal and the potash ores are the most multi-tonnage solid minerals mined and processed in the territory of the Russian Federation. Both types of the deposits have relatively simple geology aspects with large and medium-sized solids and as a rule, the most often, with the regular bedding which are characterized by the fitchery thickness and the internal structure. Such deposits are very difficult for mining and processing. The thermal modification of this of ores allows changing the physico-chemical properties of its components in such a way that their further processing - grinding, separation, transportation and storage can be carried out without the use of process water or significantly reduces its consumption. The purpose of the present study is to increase the efficiency of the mineral processing containing the layered aluminum silicate by reducing their negative impact on the basic dressing processes, the separation of suspended matters and the storage of waste. INTRODUCTION Many deposits of minerals are associated with the presence of layered silicates such as the argil, mudstones, argillaceous slate - highly hydrophilic mineral varieties which have the ability to swell in the water. This ability to self-disperse creates the great difficulties both for the extraction and the processing of such ores. Since the dressing of most minerals is associated with the use of wet processes, where in contact with water the swelling layered silicates are dispersed to a particle size of less than 50 µm, but due to their high hydrophylic property they form bonds that promote the formation of so-called structured suspensions having increased viscosity. In this case the structured suspensions make it difficult to perform the separation operations as the classification, the gravity and magnetic separation, the flotation and thickening and filtration operations."

Jan 1, 2018

By M. W. Pullen

It is recognized that the determination of electrical resistivity of the earth within a given area may furnish information concerning the location of certain mineralized strata of economic importance. Present knowledge of the electrical resistivity of the various rock formations is almost nil, and the geophysicist who is detailed to make a survey of an area without any data as to the relative resistivity of the underlying rocks is greatly handicapped. Such surveys are usually made within areas known to contain mineral deposits to aid in locating desirable points for drilling. Usually these areas have been prospected by diamond drilling, and drill cores of the various rocks and ores are usually obtainable. Were it possible to make resistivity tests in a laboratory of the drill cores or from pieces of the rocks and ore within an area before attempting a field survey, this would indicate not only the advisability for such a survey but would aid considerably in the interpretation of the results of such a survey. To be of most value a definite method should be used for all such tests, and as yet such a method has not been established.

Jan 1, 1929