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By A. Subbotin

During developing the Ingulska mine at the Mi-churinske uranium deposit in the central part of Ukraine the radioactive rock dumps have been piled. A height of dumps reaches to 15-25m. They occupy a large territory and can be a source of covering with radioactive dust the area around the Ingulska mine. Uranium content exceeds 0,01% in all dump rocks samples while in the dust fraction samples it ranges from 0,01 to 0,06%. Uranium content in road dust at the dump?s foot reaches 0,137%. A new (for Ukraine) method of f-radiography of tree and bush leaves sampled at the territory about 100km2 has been used. It is based on fission of 235U nucleuses due to heat neutron influence in a nuclear reactor and on following study of the Lausan films with tracks drawn by the fractures of these nucleuses. Uranium content of the dif-fusion-disseminated dust type is (0.9-22.2)?10-6% while in the individual particles it can be considered much more because of burned holes in Lavsan above them. The dust content with uranium in Kirovograd reaches to 20-50 part/cm2 while near the dumps it ranges from 100 part/cm2 to 300 part/cm2 in the radius of 1,5-2km from the Ingulska mine.

Jan 1, 2005

By Y. Q. Lu

Efficient flotation of fine phosphate minerals from a deslimed waste phosphate stream (-74 microns) has been achieved by both bench-scale flotation and by flotation with a 2-inch air-sparged hydrocyclone (ASH) unit. A sample was collected from the waste phosphate slime stream at the SF Phosphate Limited Operations near Vernal, Utah, for flotation experiments at University of Utah laboratories. The collector used was a mixture of fatty acid, petroleum sulfonate and kerosene. Bench-scale flotation test results show that the minus 15-micron particles have a significant adverse effect on phosphate flotation. When the minus 15-micron material was removed by a classifying hydrocyclone, improved flotation recovery and concentrate grade were realized. A bench-scale flotation recovery of 86 % with a concentrate grade of 16% P2O5 was obtained from classified waste slime (74 x 15 microns) feed material containing 11.3% P2O5 In contrast, a 90% P2O5 recovery was achieved with a concentrate grade of 16-18% P2O5 by single-stage ASH flotation. With a second stage of ASH flotation, a concentrate containing 23% P2O5 was realized at an overall recovery of 75%. These results indicate that the industrial application of ASH flotation technology for phosphate recovery from waste slimes is promising.

Jan 1, 1995

By Douglas Beahm

Energy Metals Corp. (EMC) holds numerous mineral properties in the northern portion of the Great Divide Basin. The JAB property is one of several potential properties being planned for development as a satellite facility to the greater Antelope uranium project. A National Instrument 43-101 Technical Report was completed for the JAB property. This report estimated total measured and indicated mineral resources on the property totaling 1.6 kt (3,555,022 lbs) U3O8 contained in 2.2 Mt (2.4 million st) at an average grade of 0.073 percent U3O8 at a 0.25 grade times thickness (GT) cutoff in accordance with CIM Standards on Mineral Resources and Reserves. The JAB property is located in Sections 13, 14, 15, 16, 21, 22 and 23, Township 26 North, Range 94 West, approximately Latitude 42° 14’ North and Longitude 108° 00’ West (Fig. 1). This property consists of unpatented mining lode claims and Wyoming state mineral leases com-prising approximately 850 hm2 (2,100 acres).

Jan 1, 2007

By S. V. Krishnan

Stability of fine quartz suspensions in process water is of concern in several mineral processing applications. In alkaline solutions, the presence of magnesium ions, arising from such sources as water hardness and magnesium-bearing minerals, leads to the precipitation of Mg(OH)2 which coats the surfaces of quartz. The conditions under which heterocoagulation or surface precipitation of Mg(OH)2 on quartz occur and the manner in which they influence the settling behavior of ground quartz was studied by means of settling tests, coating density determinations, zeta potential measurements and electron microscope observations. Coating density was greater when Mg(OH)2 nucleated on the surface of quartz than when the precipitates heterocoagulated on the quartz surface. The settling curves of quartz suspensions in the presence of different concentrations of MgCl2 exhibited a maximum of maxima which occurred at 10-3M MgC12 and pH 11. Interactions between quartz and Mg(OH)2, and flocculation-dispersion characteristics of quartz suspensions in this system are discussed.

Jan 1, 1983

By L. A. Taylor

The production of oxygen on the Moon utilizing indigenous materials is paramount to a successful lunar colonization. And several processes have been put forth to accomplish this. The LLOX generation schemes which have received the most study to date are those involving?: 1) the reduction of ilmenite (FeTi03) by H2, C, CO, CH4, CO-CI2, & Cl2 plasma, 2) magma electrolysis, both unadulterated and fluoride-fluxed, and 3) several others, including carbo-chlorination, HF acid leaching, fluorine extraction, magma oxidation, and vapor pyrolysis. The H2 reductions of ilmenite and magma electrolysis processes have received the most study to date. They are both feasible schemes with various pros and cons, including their feedstock requirements. However, all processes should be addressed at least at the onset of our considerations. There is an obvious need for considerably more experimentation and study. Some of these requisite studies are in progress, and this paper reviews several of the most studied and feasible processes for winning oxygen from lunar materials.

Jan 1, 1991

By AKIHIRO YOSHIMURA, HIDEKAZU KATO, KOTA TAKATORI, YASUNARI MATSUNO

Chalcopyrite (CuFeS2) is the most refractory copper mineral when treated in conventional sulfate media leaching systems. This is the first study to examine the use of a dimethyl sulfoxide (CH3SOCH3, DMSO) solution containing copper chloride (CuCl2) for the leaching of chalcopyrite. Leaching experiments for a copper concentrate composed mainly of chalcopyrite were conducted at ambient pressure at 313–413 K. The leaching fractions of Cu, Fe, S, Au, and As were investigated. It was found that 90% of the Cu was extracted in 2 h, and 94% was extracted in 4 h at 373 K, which is competitive with other conventional processes. A DMSO solution containing CuCl2 could selectively dissolve the valuable metals Cu and Au from chalcopyrite, but leave minerals with little economic value such as pyrite (FeS2) and As in the residue. Chalcopyrite is oxidized by cupric ion in proportion to the stoichiometric ratio of Cu in the concentrate to the initial cupric ion in the DMSO solution, which is enhanced by the presence of oxygen below 373 K.

Mar 12, 2021

By M. Yekeler

The critical surface tension of wetting values (Ye) of realgar (AsS), talc [Mg3si401o (OH) 2]' stibnite (Sb2S3), and sulfur (S) were determined by flotation in the absence of conventional flotation collectors as 38.7, 38.0, 35.5, and 30.0 dyne/cm, respectively. The surface tensions of flotation media were arranged by methanol. Separation of binary mixtures of these minerals was performed exploiting their Ye differences-which form the basis of the "ganuna flotation process". One step flotation test showed that sulfur floats preferentially from its mixtures with realgar and stibnite at recoveries of 73.6 and 70.7 % and grades of 81.7 and 91.2 %, respectively. The separation of stibnite from realgar gave a recovery of 4.1 % and a grade of 41.2 % for stibnite, indicate that a minimal Ye difference of 3.6±0.2 dyne/cm is essential for such separation when conventional flotation reagents are not used. This paper presents data and describes the approach employed in these separations.

Jan 1, 1994

By F. Freme

Coal production in the United States reached a record level in 2005, ending the year at 1.03 Gt (1,133.3 million st) according to preliminary data from the U.S. Energy Information Administration (Table 1). Production in 2005 was 19.2 Mt (21.2 million st) higher than the 2004 level of 1 Gt (1,112.1 million st) and surpassed the prior record set in 2001 by 5.1 Mt (5.6 million st). Although total U.S. coal consumption rose in 2005, not all coal-consuming sectors had increased consumption for the year. Coal consumption increased in the electric power sector by 2.2 percent and declined in the other industrial sector, while coking coal consumption decreased slightly.

Jan 1, 2006

The classical slope analysis and a statistical technique were used in order to determine the iron complexes formed in the organic phase during the extraction of Fe(III) from Fe-Ni-Co sulfate solutions with Di-(2-ethylhexyl) phosphoric acid (D2EHPA) in kerosene. Equilibrium constants for the extraction based on these complexes were also calculated. The complexes determined were of the general form (Fe(OH)3-nRn?sHR)x' where n varied between 1 and 2.5 and s between 0 and 3, and both were found to be decreasing as the iron loading in the organic phase increased. Values of 1,2 and 3 were generally found for x, indicating that the complexes were monomers, dimers and trimers.

Jan 1, 1988

By L. Max Scott

[INTRODUCTION] The significance of gamma exposure to uranium miners has been recognized only in the last few years. Most ore deposits which have been underground mined, were 1% or less U308. Full-time mining of this grade ore can result in exposure exceeding 1 Rem per year. Several companies in Saskatchewan are planning to mine recently discovered ore bodies which contain ore pods in excess of 10% U308. The purpose of this paper is to present dose data which can be used to estimate gamma exposure from high-grade ore deposits, and to present mining techniques which will minimize miner exposure. [Dose Estimates] When one has a point source of radiation, the conventional laws of isotropic emission and the fall of dose with square of the distance, make dose calculations relatively easy. However, if one has an area source of infinite thickness, the assumption must be made that a uniform gamma flux is being emitted from all faces of the source (Figure 1). Dose from gamma emission would fall off only due to air attenuation up to such a distance at which the source can be considered to be a point source (usually 10 times the largest dimension of the source). For short distances, such as to the cab of ore-moving equipment, the dose reduction would be negligible. Assumptions: 1) Radium and gamma-emitting daughters are in secular equilibrium with uranium. 2) All gamma radiation is emitted from radium and its daughters. 3) Average gamma energy of 0.8 MeV. 4) Uranium ore has a linear attenuation coefficient of 0.212 cm-1, similar to that of Si02(sand). 5) Uranium ore density of 3.0 gm/cm3. 6) One curie of radium emits 6.84 x 1010 photon/sec(l). 7) One percent uranium ore contains 1 x 10-8 Ci/cm3 of radium. 8) Each MeV of 0.8 MeV photon results in a dose of 2.10[ ]10-3 mRem/hr. per MeV/cm2 -sec. 1) 9) Minimum ore depth 100 cm. 10) Linear attenuation coefficient instant for radium gamma of 0.374 cm -1 [ ] The photon flux from a radioactive slab is computed as follows: [Flux = photon/cm3 3(1) 2u S] [where, us is the linear absorption coefficient of s the source (uranium ore).] Thus, 1% uranium ore, in the form of an infinite slab, emits 1613 photon/cm2-sec, which results in a dose rate of 2.71 mRem/hr. Since the dose from an infinite slab is the same as a dose from an infinite radius right circular cylinder, the only correction needed from the above dose rate is for finite radius and point of dose above the end of the cylinder (Figure 2) [Dose = mRem/hr. {E2(bl) - E2(b3) - [(E2(b1sec[E] -E2(b3sec[E]]cos[O](1)]

Jan 1, 1981

By Frederick A. Subosits

The Lithium Corporation of America's Hallman-Beam spodumene-pegmatite open pit mine is located in the Kings Mountain area of North Carolina. Figure 1. Presently this area of North Carolina is the lithium center of the U.S., if not of the whole world. The Lithium Corporation mine was started in 1968 and now covers 61,000m2 (15 acres) with projected are reserves in excess of 20 years. Lithium occurs at the Hallman-Beam property in a mineral known as spodumene (LiAlSi2O6), a lithium aluminum silicate. The run-of-mine are averages 1.43 Li2O. Figure 2 of the general Mining Division flow sheet follows the concentration of the Li2O to 5.5% and also lists the various by-products that are sold commercially. The unique properties of lithium have led to many commercial applications, some of these including lubricating greases, ceramics, glasses, glazes, welding fluxes, aluminum reduction cells, dehumidifying and air-conditioning equipment, sanitizers, polymerization catalysts, batteries, and pharmaceuticals. (3) (5)

Jan 1, 1978

By G. P. Dvoichenkova, E. A. Trofimova, M. V. Zaskevich, V. A. Chanturiya

The paper presents theoretical and practical aspects of directed adjustment of physicochemical properties (pH,Eh) and ion composition of recycle and mine water by electrochemical treatment. Treatment is run in the conditioners of diaphragm-type with production of alkaline catholyte of pH value up to 12 and acidic anolyte of pH up to 2. In process of water electrolysis the directed motion of Mg2+ and Ca2+ ions is observed from anode volume to cathode one, were they precipitate as hydroxides and carbonates; it leads to decrease of salt content in anolyte and catholyte. The anolyte has been concentrating anions, it is being saturated with oxygen, which reaches 20-35 mg/L. The results of experimental and industrial testing of electrochemical technique for mine and recycle water in flotation of diamond-containing and sulphide-scheelite, hematite, phosporite, apatite-nephelite, bauxite ores indicated the increase of recovery up to 2-1 5% and grade up to 0,5-2%, concurrent with decrease of reagent consumption from 15 to 50 %. Modules of industrial conditioners of different type capacity have been developed.

Jan 1, 1995

By David L. Hill

Newmont Gold Company's Mill No. 4 is located along the Carlin trend, about 25 miles North of Carlin, Nevada. The plant consists of a primary grinding circuit using a 7.2 m (22 ft) diameter by 2.6 m (8 ft) long semi-autogenous mill along with a 2.3 m (7 ft) diameter cone crusher. Secondary grinding is performed in a 4.8 m (14.5 ft) diameter by 9.2 m (28 ft) long overflow ball mill in closed circuit with a set of 66 cm (26 in) diameter cyclones. The ground product is fed to a typical carbon-in-leach gold leach circuit. The grinding/crushing circuit operation and control scheme are the topics of this paper.

Jan 1, 1993

By Robert G. McLusky

Since 1998, environmental extremists have waged war with the central Appalachian coal industry in West Virginia and Kentucky. In particular, they have filed three lawsuits challenging the legality of excess spoil ‘valley fills’ under CWA, NEPA and SMCRA: 1) Bragg v. Robertson, 72 F.Supp. 2d 642 (S.D.W.Va. 1999), rev’d. 248 F.3d 275 (4th Cir. 2001); 2) Kentuckians for the Commonwealth v. Rivenburgh, 204 F.Supp. 2d 927 and 206 F. Supp. 2d 782 (S.D.W.Va. 2002), rev’d. 317 F.3d 425 (4th Cir. 2003); and 3) OVEC v. Bulen, 2004 U.S. Dist. LEXIS 12690, July 8, 2004; OVEC v. Bulen, 2004 U.S. Dist. LEXIS 16078, August 13, 2004.

Jan 1, 2005

By Mandira Madhuchhanda, N. B. Devi, P. C. Rath, R. K. Paramguru, K. Srinivasa Rao

An experimental investigation of the dissolution of three base-metal sulfide minerals, namely, CuFeS2, ZnS and PbS, in hydrochloric acid medium in the presence of manganese dioxide is reported. Polarization measurements and leaching studies were employed in the study. Dissolution occurred in the following three ways: by the cyclic action of the Fe3+/Fe2+ redox couple, by galvanic interaction between Mn02 and the sulfide minerals, and because of chlorine evolution from the system. The later two routes were found more effective at higher HCI levels. PbS appeared to be oxidized easily, whereas CuFeS2 was the most difficult to dissolve. ZnS dissolution fell in between PbS and CuFeS2.

Jan 1, 2002

Coal-derived flue gases contain CO2/SO2 and these contaminants preferably have to be captured by cheap sorbents. This remediation approach is from the standpoint of addressing issues such as global warming, acid rain and development of Advanced Power Generation Systems and to realize the economic gain as well. Conventional and existing dry scrubbing technologies use regenerable sorbents which are pollutant specific and require expensive stabilizers in order to attain versatility. This paper discusses the use a novel class of sorbents prepared from the heavy metal contaminated Berkeley Pit water (Butte, Montana) by a proprietary process developed at The University of Nevada, Reno. These sorbents are activated mixed spinel ferrite (MxFe,_X04)' Preliminary experimental results show that the sorbents have good desulfurization and CO2 decomposition capacities. The decomposition effectiveness of these mixed spinel ferrites was studied at 300°C and compared against the synthetic magnetite obtained from ferrous sulfate solution in our laboratory. The results indicated that the mixed spinel ferrite had good affinity for the adsorption and decomposition. The CO2 decomposition data of both sorbents fitted the first order reaction kinetics. Even though the surface area of the magnetite was higher than that of mixed spinel ferrite, the CO2 decomposition rate of the mixed spinel ferrite was estimated to be 2.5 times higher than that of magnetite under identical conditions. The carbon analysis deposited on the sample indicated that the CO2 was 100% decomposed into carbon and other carbon! hydrogen compounds by the mixed spinel ferrite whereas the conversion was 43% by the magnetite. In terms of specific adsorption of carbon, ferrite was 3-5 times more efficient than magnetite.

Jan 1, 1996

By A. Bascetin

The human requirements have increased rapidly depending on population density and urbanization thus industrialization has grown steadily. As a result of the situation, the greenhouse gas emissions into the atmosphere and the global warming have increased slowly. Today this effect has continued to increase. Therefore, the effects of greenhouse gases in all areas of production must be controlled. The study presents the methods of determination the CO2 emissions (CO2-e) and energy consumption in aggregate production. The aggregate constitute approximately 70% by volume of concrete that has widespread use as construction material in the world. One of the most important elements in today's terms is sustainable use of resources and minimum CO2 emissions (CO2 + CO + NOx + CH4.vb.) at every stage of production of aggregate. Therefore, these elements must be taken into consideration in the aggregate production standards. The choice of production method of aggregate is very important for optimum use of energy and effects of greenhouse gas emissions. So the properties of the aggregate material must be known well to obtain the target. Within the scope of this study, the unit value of CO2-e that release when the production of aggregate in different formations is determined for our country. Thus, the effects of green house gas emission can be evaluated according to the characteristics of material in aggregate production planning. In this study, energies consumed during the production of aggregates at a quarry in Istanbul Cendere region were investigated by taking the different formations encountered at the quarry into consideration. The unit CO2 emission values per ton of produced aggregates were calculated as a result of this investigation. Besides, energy consumption values of previous months at this quarry were taken and the unit CO2 emission values were also calculated.

Jan 1, 2011

By Richard E. McGee

The paper presents a description of the procedures that were used to generate a ventilation criterion based on measurements of ambient mine air exhaust pollutant gases and ventilation airflow quantities. Today's economics dictate that a ventilation requirement be based on actual operating conditions. This will assure optimum economics and a safe working environment at the same time. The paper presents a methodology by which a ventilation requirement is based on the average maximum expected concentrations of nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), and carbon dioxide (CO2) that equipment operators in one of our Southeast Missouri mines will be subjected to. A graph has been generated whereby the expected maximum levels of NO, NO2, CO and CO2 are plotted against the ventilation quantity of a mine stope.

Jan 1, 1982

By T. McCallum, C. Cooper, C. Lewis

"Following a successful solvent extraction (SX) pilot plant demonstration in 2016, CYANEX® 600 has been used commercially to recover molybdenum from concentrate leach liquor since March 2017. Consistent with the piloting results, the commercial plant has achieved expected molybdenum recovery, a significant reduction in base consumption, and a step-change improvement in physical performance. This paper highlights the optimization activities and plant performance from startup through normal operation. INTRODUCTION Historically, tertiary amines have been the most commonly used extractant for molybdenum and rhenium recovery. Tertiary amines utilize a protonation of the ligand combined with an anion exchange mechanism as proposed in equations (1-2). R3N + H+ ???R3NH + (1) 4R3NH+ + Mo8O264- ???(R3NH+)4Mo8O264- (2) In addition to the transfer of Mo and Re, the amine transfers acid and other anions to the strip liquor. The undesirable transfer of other species increases base consumption during stripping, impacting operating costs. Additionally, lower solubility of molybdenum-amine complexes create operational challenges, resulting in diminished physical performance. The presence of colloidal Si in concentrate leach liquors and the formation of Pickering Emulsions adds to the physical plant performance challenges with the amine extractant. CYANEX® 600, a phosphinic acid-based extractant, uses a cation exchange mechanism proposed by equation (3). 2(H2R2) + MoO22+ ??(HR2)2MoO2 + 2H+ (3) The cationic exchange mechanism eliminates chemical transfer of acid and other anionic impurities and avoids some of the physical challenges of the amine extractant (emulsion and 3rd phase formation). In addition, the reagent offers high selectivity for Mo over Re, which may be desirable in certain moly pressure oxidation (POX) flowsheets. Alkali base (ammonium hydroxide, sodium hydroxide, sodium carbonate, etc.) is used for molybdenum stripping. Therefore, reduction or elimination of chemical acid transfer from extract can significantly reduce base consumption in strip. Extensive laboratory and pilot plant testing was completed to evaluate the use of CYANEX® 600 for molybdenum recovery at Freeport-McMoRan’s Bagdad operation. The test work and pilot demonstration confirmed a reduction in base consumption along with improved selectivity. In addition, the evaluation highlighted a step-change improvement in physical performance over the incumbent amine extractant. The decision was made to convert the commercial operation to CYANEX® 600 in March 2017."

Jan 1, 2018

By C. A. Born

AMAX Inc. climax's mine-mill complex at Climax, Colorado is best known for its molybdenite production: 50,000 TPY of molybdenite flotation concentrate (95% MoS2) from mill heads containing 0.35% molybdenite. Less recognized are the byproducts that are concentrated from the tails generated in the rougher flotation circuit (see Figure 1). Climax recovers a heavy mineral concentrate by passing the rougher tailings from molybdenite flotation over Humphrey spirals (Figure 2a). This concentrate is floated using xanthate at pH 4 to remove sulfides, principally pyrite. The tails from the pyrite float are then cleaned of quartz, feldspar and light minerals by tabling (Figure 2b). Amine flotation follows at pH 1.5 and 75°C to float monazite (Figure 2c). The present circuit at Climax dries the monazite flotation tailings and utilizes high intensity cross-belt magnetic separation Figure 2d) to generate a high grade wolframite concentrate and a low-grade cassiterite product, both of which are contaminated with the mineral brannerite, (UO, TiO, UO2)TiO3. The uranium specifications have recently become difficult to meet due to the increasing percentage of brannerite reporting in the mill feed. A plant is being built utilizing hot sulfuric acid and sodium chlorate to leach this uranium from the monazite flotation tailings prior to their being fed to the wolframite- cassiterite magnetic separators. This modification is the subject of our paper.

Jan 1, 1975