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Lead and zinc ore deposits of the Mississippi Valley type (MVT), located in the Olkusz ore district (south Poland) are connected with strongly karstified Triassic carbonates, mainly dolomites. In this paper changes in the groundwater inflow quantities to the Zn-Pb mines in the Olkusz region are discussed: Boleslaw, Olkusz and Pomorzany. Themining activity in the Olkusz region is connected with probably highest groundwater inflows in the World. Occurrence of the karstic systems within Triassic rocks is a reason for extremely high water inflow to the underground mining workings, obtaining the value of 40 m3/min in Boleslaw mine, about 95 m3/min in Olkusz mine and about 300 m3/min in Pomorzany mine. The main problem in the dewatering of the Triassic ground is the presence of the water-filled karstic systems. After the cutting of the karstic channels or caverns by the mining workings an abrupt increase of the water inflow to the mine dewatering systems is observed. Karstic forms, as an intrinsic drainage systems for fissures and matrix porosity, are responsible for enlargement of the recharge zone of mines.

A composite mixture of three typical Cu/Zn complex ores, namely black-, yellow- and altered-ore, from Cayeli deposit in Turkey, was used for leaching experiments under atmospheric pressure in ferric sulphate solutions, in order to study the reaction kinetics of the copper and zinc dissolution in the temperature range from 50 to 80°C; also in the presence of a solvent for elemental sulphur, such as CCl 4 . Owing to the fact that quite low copper extraction yields were obtained and to the clearly evident necessity of using pressure leaching in autoclave at higher temperatures, a tentative process of the ore enrichment by selective or bulk-flotation was then examined. Leaching tests in an autoclave at temperatures ranging from 100 to 230°C were carried out on the bulk-concentrate produced. Good extraction yields for both metals were achieved at 140°C after a few hours leaching by ferric sulphate.

In past years, regional to detailed gravity and aeromagnetic surveys have been employed to develop a greater understanding of the geology in and around the Mount Isa copper and silver?lead?zinc ore bodies. In recent years, several downhole electromagnetic (DHEM) surveys have been conducted, primarily to target further massive sulphide mineralisation. This paper will present some of the results from these geophysical surveys. Gravity data show a complex but clearly anomalous effect over the mineralisation. A large negative anomaly is correlated with a zone of deep oxidation and leaching in the footwall, with a complex but strong positive anomaly associated with the silica dolomite alteration and silver?lead?zinc mineralisation. Aeromagnetic data over the ore zone are partly obscured by the cultural effects of the city and mine. The removal of the cultural effects has been attempted by measuring the field at a number of terrain clearances and then calculating an actual vertical gradient. These vertical gradients were then used to compute a 'culture' filter. The data, after filtering the cultural effects, suggested that the silver?lead?zinc ore bodies produce an anomaly with a magnitude of approximately 35 nT. Two holes have been probed using DHEM. The results show a complex superposition of responses from many sources and demonstrate the applicablilty of DHEM in exploring for base-metal mineralisation, within the conductive environment at Mount Isa. They also show the heterogeneous nature of the system given the differing responses from both holes.

An indirect complexometric method is described for the determination of zinc(II) using 2,2′-bipyridyl as masking agent. Zinc(II) in a given sample solution is initially complexed with an excess of EDTA and surplus EDTA is titrated with lead nitrate solution at pH 5.0–6.0 (hexamine), using xylenol orange as indicator. An excess of 2,2′-bipyridyl is then added, the mixture shaken well and the EDTA released from the Zn-EDTA complex is titrated with standard lead nitrate solution. Results are obtained for 3–39 mg of Zn with relative errors ≤ 0.5% and standard deviations ± 0.06 mg. The interference of various ions are studied. The method is applied for the determination of zinc in its alloys and ores.

Zn-Pb-Ag ores at Nanisivik, northwest Baffin Island, are hosted by upper Proterozoic laminated dolostone of the Society Cliffs Formation. Sulfide orebodies containing pyrite, sphalerite, galena, sparry dolomite, and pyrite pseudomorphous after marcasite are characterized by well-banded ore textures considered to have resulted from the progressive replacement of carbonate wall rock. Textural and mineralogical variations enable the Main orebody to be divided into three vertical and four horizontal ore zones. The upper lens of the Main orebody may be further subdivided into six texturally distinct, laterally extensive mine units.In the eastern upper lens, where textural variations are best developed, fluid inclusions indicate that most ore mineralization took place over the temperature range of 165 degrees to 210 degrees C and involved a brine containing 20 to 38 wt percent NaCl equiv. The sulfur isotope compositions of main- and late-stage pyrite crystals range from (delta 34 S = 27.4 to 28.0 per mil. Iron contents of sphalerite vary from 14 to 0 mole percent FeS, corresponding to well-developed color zoning, and constrain the oxygen activity of the ore fluid to 10 (super -46) to 10 (super -41) at 200 degrees C during sphalerite precipitation. Interbanded primary marcasite and sparry dolomite gangue indicates that the ore fluid fluctuated around pH = 5.Ore formation is modeled based on processes involving in situ reduction of sulfate by hydrocarbons and minor H 2 S encountered at the site of ore deposition. The location and configuration of the orebodies was probably controlled in part by the former position of a horizontal fluid interface. Banding is likely the result of repetitive sulfate reduction, metal precipitation, wall-rock dissolution, and dolomite recrystallization in response to the pulsatory influx of ore fluid. Textural and mineralogic variations probably resulted from slight variations in the availability of reduced sulfur.

The isotopic composition of ore lead in galena from the volcanogenic sulfide ores at Garpenberg district is presented. Despite of textural, compositional, and mineralogical differences, as well as the variable extent of deformation of the various sulfide ore types, the ores are characterized by a narrow range in lead isotopic composition. Dolomite-hosted ores are commonly more radiogenic than those hosted by skarn or altered volcanic rocks. Compared with the average growth curve of Stacey & Kramers, the ore lead at Garpenberg is slightly enriched in radiogenic lead. The influence of metamorphism on the ore lead composition of galena samples is negligible. The observed trend in the standard diagrams may be explained in terms of a mixing line, where the ore lead was derived from two different crustal sources originally enriched in radiogenic lead (e.g. volcanic and sedimentary rocks). Alternatively, it could represent sulfide ores of slightly different ages derived from a common rock source. The co...

The polymetallic Madem Lakkos sulfide deposit in northern Greece is hosted within marble of the Mesozoic (?) Kerdylia Formation, a high-grade metamorphic complex composed of migmatitic biotite gneiss interlayered with marble, hornblende gneiss, and amphibolite. The Kerdylia Formation is invaded by a variety of foliated and nonfoliated intermediate to felsic intrusions of Tertiary age. The Madem Lakkos deposit is long-believed to have formed from a single epigenetic hydrothermal replacement event related to Tertiary magmatism, but this research has recognized the presence of three different and distinct ore types in the deposit that resulted from a much longer and more complex genetic history.Based on ore mineralogy, textures, and geochemistry, the Madem Lakkos ores can be characterized as (1) massive sulfide ore, (2) disseminated sulfide ore, and (3) skarn ore. The massive pyrite-sphalerite-galena ore exhibits abundant and well-developed metamorphic structures and textures that indicate the ore has been metamorphosed to upper amphibolite grade, at temperatures of at least 600 degrees C, together with its marble and gneissic host rocks. These textures include foliated-lineated galena and sphalerite, slip planes and deformation twinning in galena and sphalerite, and granoblastic annealing-recrystallization features with the development of 120 degrees triple-point junctions in galena, sphalerite, and pyrite. Despite its metamorphism, this ore preserves a generally stratiform nature with sharp, unaltered host-rock contacts, a regional and stratigraphic association with chemical and possible evaporitic metasedimentary rocks, compositional layering, and metal zoning that are consistent with formation as a sedimentary massive sulfide deposit.Disseminated sulfide ore, the most abundant type in the deposit, consists of complex veins and irregular manto-type impregnations in altered marble that are composed of pyrite, sphalerite, tennantite, chalcopyrite, arsenopyrite, galena, seligmannite, boulangerite, and minor amounts of a wide variety of additional sulfominerals in a quartz-sericite-manganiferous carbonate gangue. Disseminated sulfide ore transects and has reacted with the earlier massive sulfide ore and does not exhibit evidence of metamorphism. Euhedral zoned crystals with mineral and fluid inclusions, open-space fillings, and complex textural relationships are characteristic of this ore type and indicate that it formed through the replacement of marble by reaction with hydrothermal solutions. Disseminated sulfide ore is enriched in Cu, As, Mn, Sb, and Bi in comparison with the massive sulfide ore.Skarn ore contains pyrite, chalcopyrite, scheelite, and minor amounts sphalerite, galena, and Pb-Bi sulfominerals in a calc-silicate assemblage of gangue minerals that includes andradite-grossularite garnet, diopside, calcite, quartz, epidote, and minor chlorite, actinolite, and magnetite. Textures similar to those found in the disseminated sulfide ore and an absence of metamorphic features are characteristic of the skarn ore. Highly saline fluid inclusions in quartz from the skarn ore suggest that high-temperature, low-pressure porphyry copper-type magmatic fluids were involved in generation of this ore. Skarn ore does not exhibit a spatial relationship to igneous rocks in the mine but may be related to porphyritic quartz diorite stocks a few kilometers to the south that have halos of propylitic and phyllic alteration and porphyry copper-type mineralization.The different ore types are characterized by a very similar lead isotope composition ( 206 pb/ 204 pb = 18.78-18.82, 207 pb/ 204 pb = 15.67, 208 Pb/ 204 pb = 38.88-38.92), which lies within the restricted field of igneous rocks from northern Greece. Although this resemblance between ore and igneous rock lead has been used to support a magmatic origin for the Madem Lakkos and related sulfide deposits, the uniform isotopic composition of all lead in this tectonically active region weakens this argument. If, as is proposed, the massive sulfide ore was initially deposited as a synsedimentary body within the Kerdylia Formation, the modern model age of the lead strongly suggests that mineralization took place only a short time before the rocks were metamorphosed.The superposition of multiple ore types having different mineralogic and chemical compositions, textures, metamorphic grades, and apparent ages indicates a complex, multistage, polygenetic origin for the Madem Lakkos deposit. An interpretation consistent with this evidence is that synsedimentary massive sulfide ore was deposited as a stratiform body within a sequence of probably Mesozoic shallow-water platform carbonate and clastic-volcaniclastic sediments, possible evaporitic sediments, and lesser amounts of volcanic rocks. This ore and its host rocks were metamorphosed to upper amphibolite grade during Cretaceous-Tertiary regional metamorphism.Coregional, post-tectonic intrusions generated heat and magmatic fluids that produced skarn and skarn ore by replacement of marble at temperatures above 360 degrees C. A continuing but cooling convective hydrothermal system mixed magmatic fluids with meteoric water. These hydrothermal fluids permeated marble and massive sulfide ore peripheral to the skarn ore, reacting with them and extensively altering the marble to form disseminated sulfide ore. Massive sulfide ore and related chemical sedimentary rocks were partly dissolved by and incorporated into the hydrothermal solutions, thereby contributing Pb, Zn, Fe, Mn, Ag, Au, and minor amounts of other constituents to the hydrothermal system. Fe, Cu, W, As, Sb, and Bi were probably magmatic contributions.

A new concept has been developed for the production of zinc from zinc and complex zinc concentrates. It is a two-stage process involving oxidation of zinc sulfide to oxide and dissolution into slag and the fuming of zinc from the slag by injecting carbonaceous materials into it to produce zinc vapors which can be subsequently condensed in a lead-splash condenser such as those used in the Imperial Smelting Process (ISP). In this paper, the effects of the quantity of air, temperature, and concentrate feed rate have been discussed on the production of zinc-rich slag, which is the first stage of the proposed process.

The Angouran mine in northwestern Iran is a very high grade zinc ore deposit with some 18.2 Mt of nonsulphide ore (28.1 % Zn, 4.2 % Pb, 110 g/t Ag) and an additional 4 Mt of sulphide ore (40.4 % Zn, 1.9 % Pb).

The possibility of production of ceramic floor tile based on kaolin from the Angrenskoe Deposit and flotation waste from a lead-zinc plant (SOF) is studied. The main physicochemical properties of ceramic specimens sintered from mixtures with different contents of kaolin and SOF are described. An optimum temperature regime for the firing process is suggested.

Lead-Zinc mineralization in some parts of Izzi area has attracted a number of private miners into the area. The miners can not be said to have been very successful. This is due to the nature of mineralization which occur in isolated vein-lodes that are fracture controlled. Their information on the mineralization or prospecting has been based on reports of Villagers, Shallow hand-dug pits and of douncing rod exercise. Results of 30 electric Self Potential (SP) measurements at two prospective zones of the locality has positive responses for Sulphide mineralization indicated by high negative SP anomaly along two separate bands. The trend of anomaly shows prospective zones of mineralization in the North-South axis across the area, with dip direction towards the North, following the trend of the shale host rock and along the two prospective bands. Result of seven Vertical Electric Soundings (VES) show that the overburden material to the shale host rock consisting of Sandy-Siltstone and Shaly-Mudstone has average depth between 25-39m, given thickness of 11-19m across the area. The Shale host rock is classified into three layer-zones based on resistivity value. A non mineralized zone, with resistivity value less than 3000 (ohm-m). A mineralized zone with resistivity value between 3000 to 5000 (ohm-m) where sphelarite (Zinc ore) is predominant and a highly mineralized zone with resistivity value between 6000 to 8000 (ohm-m) where Galena (lead ore) is dominant. The two bands are due to faulting . Band A at the down throw portion of the fault corresponds to the topographically low area and Band B at the upthrown, corresponds to high topography zone of the study area. KEY WORDS: Fault-fractures, Vein-lodes, Dip, Contours, Resistivity, Geo-Electric Section, Anomaly and Mineralization Potential. Global Jnl Geological Sciences . Vol.2(1) 2004: 61-66

A flow injection (FI) in-valve-mini-column packed with Chelex-100 resin is proposed for on-line sample pretreatment for some metal ions, namely, Cd(II), Pb(II) and Zn(II), prior to simultaneous determination using ion chromatography (IC). A solution containing a mixture of the cations was first passed through the in-valve-mini-column, followed by on-line elution. The eluate was then flowed further to an injection valve and was injected into an ion chromatograph. Conditions of the system were optimized. A single standard calibration was possible. The recoveries of cations were found to be in the range of 95-105%. The developed method was applied to the accurate analysis of zinc ore samples.

The primary goal of this study was to evaluate anecdotal evidence that within Jasper and Newton Counties, Missouri, two counties within the Tri-State Mining District, granular mine tailings were commonly used in place of river sands in wall plasters and mortar. Interior wall plaster and mortar samples from structures in this mining district were analyzed for lead, cadmium, and zinc, and compared to samples from Springfield, MO (comparison site). The Jasper and Newton County samples showed elevated concentrations of the three elements, consistent with the inclusion of mine tailings, with a number of samples containing lead and cadmium at concentrations greater than EPA remediation targets for yard soil. X-ray diffraction studies showed the presence of the zinc ore minerals, sphalerite and hemimorphite, in high level samples. Thin section optical studies identified the major component of the aggregate as chert, a mineral abundant within the tailing piles. Because dust from crumbling plaster and mortar could represent an avenue for significant heavy metal exposure to building occupants, we suggest that there may be associated health consequences that should be further evaluated.

Mineral catalysis may be the dominant mechanism controlling carbon–hydrogen bonding in Earth’s interior.

Low molecular weight polyacrylamide (PAM) polymers were used to separate copper-activated sphalerite from pyrite in the presence of isobutyl xanthate (IBX). The effects of carboxyl, sulfonate, hydroxyl or thiourea functional groups attached to the polymers on the flotation recoveries of sphalerite and pyrite were studied as a function of polymer concentration and order of reagent addition. It was found that all the PAMs depressed pyrite flotation with no or little depression of sphalerite. The following order for pyrite depression was obtained: hydroxy>carboxyl≥thiourea>sulfonate, and for mineral selectivity: carboxyl≥sulfonate>hydroxy≫thiourea. It was also found that a greater mineral depression was obtained for the coarser particles and when the PAMs were added before the collector.

The application of SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) is reported for analysis of huge Raman image data of dust samples collected in the vicinity of lead and zinc smelters. The Raman data were carried out using Raman microprobe and automated mapping stage at 1 μm step size over at most 80 μm ×70 μm sample area for each experiment. Numerous significant pure spectra were extracted by the SIMPLISMA method. Results provide the number of major as well as minor chemical species. Concentration maps of the resolved components demonstrate the heterogeneity of individual particles at level of 1 μm spatial resolution. A discussion is given addressing the analysis aspects of SIMPLISMA and the relative merits and drawbacks of the technique in comparison with conventional analysis from two real Raman image data.

Three methods of improving zinc concentrate grade in the flotation of two massive sulphide ores were investigated. These methods involve the use of oxygen gas conditioning, copper specific collectors or selective polymeric depressants. The results obtained demonstrated that all three methods provide high zinc concentrate grades through depression of iron sulphide minerals. It was also found that by combining two methods, reagent consumption could be decreased without decreasing overall performance.

X-ray absorption spectroscopy and x-ray fluorescence microprobe studies of 35-million-year-old calcite from a Mississippi Valley–type zinc ore deposit indicate substitution of tetravalent uranium for divalent calcium. Thus, tetravalent uranium has a stable location in calcite deposited under reducing conditions. This result validates uranium-series dating methods (including uranium/lead dating) for ancient calcite and shows that calcite provides a sink for uranium in deep groundwater aquifers and anoxic lacustrine and marine basins.

Oxygen isotope fractionation in the zinc oxides has been calculated by means of the modified increment method. The results suggest that zincite is slightly enriched in 18O relative to the franklinite of the spinel-type structure but considerably depleted in 18O relative to the franklinite of the inverse spinel-type structure. The zinc oxides are significantly depleted in 18O relative to water under hydrothermal and metamorphic conditions. The oxygen isotope analyses of mineral pairs including the zinc oxides and the common gangue minerals such as calcite and quartz can constitute a sensitive isotope geothermometer. Application of oxygen isotope geothermometry to natural assemblages is attempted for the calcite-zinc ore mineral pairs from the Sterling Hill deposit in USA. The results indicate that the temperature of the zinc mineralization may be in the range from 410° to 630 °C and thus lower than the metamorphic temperatures of granulite facies. A metamorphic fluid could have been involved in the formation of the zinc ore minerals. Franklinite would structurally be an inverse spinel in the infancy of its formation, and thus could have originally evolved from Zn2 + substitution to Fe2 + of magnetite at the high temperatures.

The present study rests on the treatment's process optimization by flotation of the Chaabet El Hamra's zinc ore (Algeria), for the optimization parameters relating to the production. The choice of parameter to optimize for flotation, and the arrangements and the scheme's initial flotation, while considering the studies already undertaken, all this has enabled us to better focus our work, while minimizing the consumption of reagents in different tests, This has resulted in successful outcomes. Keywords: Flotation, Sphalerite, Zinc, Amylxanthate,HAZEN, time.

Kosovo lead and zinc ore deposits are located in the Trepca Belt which extends for over 80 km. Several ore deposits occur in that belt, with the most important - Stan Terg (Trepca). Stan Terg deposit originating at the contact between volcanic breccias and carbonate rocks. Two different types of mineralization can be distinguished. The older one has origin related to pneumatolitic processes, when skarns were formed. The more recent one was formed by hydrothermal processes and has the largest economic importance. Over 70 minerals have been recognized in the Trepca deposit. Further mineralogical investigations will allow for the identification of other rare minerals.

A flow-injection, cold-vapor atomic absorption spectrophotometric method was developed for the determination of trace amounts of mercury in a proposed zinc ore concentrate Standard Reference Material (SRM 113b). The samples were digested with nitric and hydrochloric acids in closed Teflon digestion vessels. The experimental details for sample preparation and the flow injection method are discussed. The effect of matrix and various acid concentrations on the extraction and subsequent analysis of mercury were also studied. The method has a detection limit of 0.08 μg Hg/g in the sample. A certified reference material (CZN-1) was analyzed and the results obtained agreed well with the certified value.

The search for economic Zn-Cu-S- deposits has been going on in the Pyhasalmi area, central Finland for nearly 30 years . In 1958, when the Pyhasalmi ore deposit was discovered the studies undertaken by Outokumpu Exploration in the area were given a big boost. immediately after discovery of the deposit, systematic magnetic, EM and gravimetric surveys were started over and in the vicinity of the orebody . The massive pyritic Pyhasalmi Zn-Cu-S ore causes a distinct gravimetric and electrical slingram anomaly . The ore contains 2 - 4% pyrrhotite ; which greatly improves its electric conductivity . The results of the geophysical survey had a decisive impact on the instruments and methods used in the following search for a massive pyritic zinc ore of the Pyhasalmi type .

The mining of zinc in Tennessee dates back to 1854 although the presence of zinc minerals had been reported as early as 1844 by Gerard Troost, the first State Geologist. When the Mossy Creek open pit mine, in what is now Jefferson City, Jefferson County, was opened, it became the first mine in what is now known as the Mascot-Jefferson City Zinc District. In these early years, only the oxidized ore was removed, and mining stopped when the sulfide ore zone was reached because a method to treat “hard ore”, as it was called, had not yet been developed. Mining continued at the Mossy Creek operation until 1858, then ceased through the Civil War years until 1867, at which time the property was taken over by the East Tennessee Zinc Company. This company built a smelter to manufacture zinc oxide, but after only a few months of operation, the company became involved in litigation and mining ceased. In 1882, the Mossy Creek property was sold to the Eades, Mixter and Heald Zinc Company which operated intermittently until 1894, becoming the first substantial zinc mining company in Tennessee as well as the first to produce significant amounts of sulfide ore. This latter was made possible by the construction of a zinc smelter at Clinton, Tennessee, some 45 rail-miles to the west. The Mossy Creek mine was operated or prospected only sporadically thereafter, and was closed by its final owner, the American Zinc Company, in 1919. In the meantime, the discovery of lead and zinc ore in the Powell River area of Claiborne and Union Counties, some 30 miles northwest of Jefferson City, caught the attention of the mine operators. In 1883, the New Prospect mine was opened with only the lead recovered. By 1889, Eades, Mixter and Heald had taken over, erected a mill and mined the property intermittently until 1897. The lead was handpicked and shipped to New Jersey while the zinc was barged to the smelter at Clinton. There was little further activity until World War II when the very high grade pillars were robbed. The only other producing mine in the Powell River district was at Straight Creek. It operated from 1880 to 1894, the latter part of this period by Eades, Mixter and Heald Zinc Company, which also built a mill. Beyond this there was only a short period of exploration and mining from 1906 to 1908 and another effort by Universal Exploration Company in the latter part of World War II.

The abundance of iron in Mississippi Valley–type lead-zinc deposits and districts varies greatly; some deposits contain large amounts and others are almost free of iron. Iron in Mississippi Valley–type deposits is largely paragenetically early pyrite or marcasite that was replaced by sphalerite and galena, often in the central part of the deposit or district. Sedimentary exhalative and Irish-type base metal deposits, which also form from basinal brines, have similar variations in iron content. Calculated metal contents of brines in equilibrium with galena, sphalerite, and pyrite show that iron is significantly more abundant than lead and zinc in high-temperature (>200 °C), relatively acid brines with low sulfur contents, whereas zinc dominates under most other conditions, including brines with high temperatures and high sulfur contents. These results suggest that iron-rich Mississippi Valley–type deposits form from brines expelled from the deepest, hottest parts of sedimentary basins.

Ratio measurements can be made by inductively coupled plasma mass spectrometry (ICP-MS) with precisions approaching 0.1–0.2% relative standard deviation, under carefully controlled conditions. This capability is well suited to isotope dilution quantification, since quantitative data are based solely on ratio measurements. Conversion of the precision of isotopic ratio measurements to accuracy requires attention to both the operation of the ICP mass spectrometer and to the sample preparation procedures. The concentration of Mg, Cd, Mo and Pb were determined in synthetic samples with average precision and accuracy of

The Number One orebody is the largest and most sulfide-rich ore zone (at least 200,000 tons containing 8.4 wt % Cu) at the Ruby Creek copper deposit, in the southwestern Brooks Range of Alaska. Pyrite and copper-bearing sulfide minerals are concentrated within the matrix of a dolostone breccia body, which is enclosed by phyllite and calcic marble of Middle to Late Devonian age. The Number One orebody has three mineralogical zones that grade into each other: (1) an outer zone, widest toward the hanging wall, containing mostly pyrite with minor amounts of chalcopyrite and traces of carrollitc and sphalerite; (2) an intermediate zone containing major chalcopyrite and pyrite, minor tennantite-tetrahedrite, bornitc, carrollitc, and sphalerite, and traces of galena; and (3) a core zone containing major bornitc, chalcopyrite, pyrite, and chalcocite, minor carrollitc, digenite, and sphalerite, and traces of galena, covellite, and the germanium-bearing sulfides renierite and germanitc. Small clots of anthracitelike organic material (anthraxolite) are found throughout the ore. Much of the pyrite is fine grained and was deposited before the other sulfides, being increasingly replaced by Cu-bearing sulfides from the outer zone to the core. Some of this pyrite recrystallized into coarser grains having cobaltiferous rims, and these grains were generally not replaced. The sulfide minerals are commonly pseudomorphous after lath-shaped crystals within the dolomite clasts; no unreplaced examples were found, though the crystals closely resemble those of marcasite. The abundant fine-grained, porous pyrite also may represent replacement of marcasite. The origin and timing of brecciation and ore deposition remain unknown, though dolomitization and ore deposition appear to have occurred in preexisting carbonate breccia. Close mineralogical and geologic similarities are noted with the Kipushi Cu-Zn-Pb deposit in Zaire and with several other carbonate-hosted copper-rich organic-bearing deposits. The common concentration of the rare metals Co, Ge, and Ga in these structurally and mineralogically complex ores should increase their economic attractiveness.

A method has been developed for routine determination of fluorine in zinc sulfide ores by activation with fast neutrons from a 6.6 Ci227Ac−Be isotope source and counting of the 4.5 to 7 MeV gamma-rays of the product nuclide16N. Samples and standards consist of pellets pressed from a mixture of powdered material with wax or graphite. Samples and standards alternate in a sequence of 20 seconds irradiation, 4 seconds decay and 20 seconds counting. This analysis sequence, including the computation of the analysis results from the counting data automated by means of a LSI-11 Microprocessor with 12K×16 bit memory. The zinc ores, containing 0.3 to 0.7% fluorine have been analysed with a precision ranging from 1.56 to 1.33% relative. As a test for the reliability of the method, three standard reference materials were analysed in the same way as the zinc ore samples.

Energy dispersive X-ray fluorescence method for the determination of iron /3.5–26% of Fe/, zinc /0.5–9% of Zn/ and lead /0.05–5% of Pb/in zinc-lead ores containing arsenic has been worked out. In order to eliminate the interelement effect intensity correction equation had been proposed. The relative standard deviation of the determination varies from 3.6 to 9.2% depending on the element.

Strata-bound dolomite-hosted lead-zinc deposit. Crusts of colloform sphalerite, galena, pyrite, and marcasite (stage I mineralization) were deposited on the surfaces of the karst-produced solution cavities. Reduced sulfur was produced by sulfate-reducing bacteria within the karst system. A second stage of mineralization consisting of coarsely crystalline sphalerite, galena, pyrite, and marcasite occurs in veins and as the matrix for dolomite breccias.--Modified journal abstract.

Computerized bibliographic databases have become sufficiently well developed and widely available to researchers that they have become potentially an important source of time series estimates of the growth of scientific literature. This paper uses the GEOREF3 database in such an application to estimation of the growth of geoscience. It is found by comparison with studies previously done from the hardcopy equivalents of GEOREF3 that the computer-derived time series can achieve results similar to their equivalents and do this more efficiently, more inexpensively and more comprehensively. Examples are given for geoscience as a whole, and for the literature related to several mineral commodities: iron ore, lead ore, nickel ore, petroleum and natural gas, radioactive minerals and ores, and zinc ore.

A multi-element geochemical study of the wall rocks of intermediate to felsic volcanic-hosted massive sulfide deposits was carried out to identify pathfinder elements which significantly enlarge the size of exploration targets. Drill core samples from the Crandon massive sulfide deposit in Wisconsin, and outcrop samples from the United Verde and Iron King deposits in Arizona, and from the Captains Flat, Mt. Costigan, and Wiseman Creek deposits in New South Wales, Australia were analyzed. Because anomalously high fluorine values have been described in several volcanic-hosted ore systems, fluorine was included in the study. All of the above deposits have patterns of fluorine enrichment around ore. Drill core samples from two noneconomic prospects within ten miles of the Crandon deposit contain background to only weakly anomalous fluorine values. At the large Crandon deposit (> 50 million tons of zinc, copper ore), fluorine enrichment extends approximately 320 m into the footwall rocks and at least 220 m into the hanging wall rocks. At the large United Verde deposit (> 50 million tons of copper, zinc ore), fluorine enrichment is recognizable in the footwall rocks at least 650 m from the ore. At the smaller Iron King deposit (five million tons production of zinc, lead, copper ore), fluorine enrichment extends for a distance of approximately 60 m into the footwall rocks. At the small deposits in New South Wales ( Fluorine occurs in some hydrothermal systems unassociated with mineralization and is therefore not a specific signature of ore-forming processes. From the work completed, many massive sulfide deposits in volcanic rocks occur in hydrothermal systems which contain fluorine. On the basis of the data presented, if anomalously high fluorine values do exist in an exploration search area, the chances of finding a massive sulfide ore deposit are improved. Genetic models for volcanic-hosted massive sulfide ore deposits have concentrated on rock textures, alteration mineralogy, and geochemistry of the ore metals. From the data presented, fluorine should be considered as a component of massive sulfide systems in intermediate to felsic volcanic rocks, and should be considered as a possible complexing agent for the ore metals.

Soils and soil gas samples were collected along three traverses across the copper-zinc ore bodies at Johnson Camp, in southeastern Arizona. The copper-zinc ore occurs as isolated sulfide and oxidized sulfide replacement bodies in limestone host rocks covered by 10–225 m of alluvium. Samples were analyzed for helium using mass spectrometry and for carbon dioxide and sulfur compounds by gas chromatography. Above average concentrations of carbon dioxide and helium in soil gases, as well as above average concentrations of carbon dioxide degassed from soils, occurred over and adjacent to all three ore bodies. Carbonyl sulfide and carbon disulfide degassed from soils occurred in the vicinity of ore bodies as deep as 150 m, but not to 225 m depth. Volatile constituents in soil gas samples collected by hollow probe defined the ore bodies better than volatile constituents degassed from surficial soil samples.

The collectorless flotation of sphalerite due to inadvertant activation is quite limited and the floatability of iron-bearing sphalerites with the aid of collector is due to the formation of diethyldixanthogen which forms a 5-membered ring complex with zinc(II). Hence activation of sphalerite by heavy metal ions, prefarably the softer species, is necessary in a majority of flotation circuits. Copper(II) ‘dopes’ ZnS phase and the surface compound slowly gets converted to covellite with simultaneous formation of sulphur, It has been reported that the formation of sulphur is also observed during activation by other metal ions; but lacks firm experimental support. However the standard redox potential of S2−/S0 indicates that the formation of sulphur is favourable, more so in acidic medium. But the sulphur formed is highly unstable and hence undergoes SN 2 reactions with the reductants. A majority of workers agree that rate of activation take place in two stages and slow stage of activation is due to diffusion...

Greenex A/S is a Danish Limited company, which since 1973 has operated a lead/zine mine at Maarmorilik on the west coast of Greenland, 500 km north of the Polar Circle. In 1981, 650,000 tons of lead and zinc ore were mined and concentrated to 38,000 tons of lead, 144,000 tons of zinc concentrate and 468,000 tons of waste — called tailing-containing minerals of no value and traces of lead, zinc and cadmium. After chemical treatment, the tailings are discharged in a sea water suspension into a threshold fiord in 40 m depth via an especially constructed outled system. When the tailings are mixed with sea water, cadmium, lead and zinc are partly dissolved and spread in the marine environment by natural transport processes. Determined efforts have been made over the years to protect the natural environment, aimed especially at reducing the metal content in the tailings, and in particular the content of soluble metals. Good results have been achieved from these comprehensive endeavours which have been undertaken at a cost of 40 mill. Dkr. Since 1977, the biology and marine chemistry as well as the oceanography, including mixing and transport mechanisms in the sea water around Maarmorilik, has been studied intensively by Greenex in cooperation with a great number of both international and Danish experts. Today, the marine environment around Maarmorilik is one of the best studied areas in the world.

A uranium- and apatite-bearing horizon was found in close association with the pyrite, zinc, and copper ores of the middle Precambrian Lampinsaari ore complex, Vihanti. The characteristic rock types in the horizon are phosphorite-banded dolomite and fine-grained apatite-bearing quartz-plagioclase gneiss, a metamorphic derivative of phosphatic tuff. Parts of the phosphatic metatuff contain pyrite bands and, on the basis of position and geochemical characteristics, the pyrite-banded metatuff is regarded as a termination of the pyrite ore proper and hence, at least partly, the U-P rocks belong to the same horizon.Uranium shows a strong correlation with apatite in both distribution and content. In the phosphorite bands uranium seems to be mainly bound in uraninite and in the phosphatic metatuff mainly in apatite. The mean uranium content in the horizon is 0.03 percent and the mean P 2 O 5 content of grade 3 to 5 percent. The thorium content was found to be less than 10 ppm.The isotopic composition of sulfide sulfur was determined in 43 analyses and found to be strongly dependent on the lithology of the horizon. The changes in pH of the source fluids are regarded as the principal factor behind this interdependence. The hydrothermal temperature range is assumed for the formation of at least the phosphorite-banded dolomite. A volcanic exhalation mechanism is favored by the delta 34 S pattern of the sulfides as well as by the paleolithology of the uranium- and apatite-bearing horizon.

Magmont ore samples have a paragenetic sequence of mineral deposition. Early disseminated mineralization was followed by sulfides characterized by colloform texture. These were succeeded by the deposition of crystalline sulfides, quartz, and calcite in fractures and vugs. The sequence is characterized by overlap and repeated deposition of sulfide minerals. Galena and chalcopyrite were deposited during six intervals; sphalerite, marcasite, and pyrite during four; and dolomite and quartz during three. The interpretation is that the Magmont ore deposits, like other deposits in the Viburnum Trend, were formed over a long period of time during which the ore-bearing fluids passed through sequences of mineral deposition, nondeposition, dissolution, and subsequent deposition.The general paragenetic sequence corresponds with the areal and vertical mineral zoning of the Magmont orebodies. The earliest copper and zinc mineralizations occur in the lower and central portions of the breccia that initially controlled the deposition of the ore. Younger lead mineralization occurs within and peripheral to the copper and zinc. The youngest minerals are concentrated in the upper and outer portions of the orebodies. The relationship of paragenesis to zoning suggests that the ore fluids moved upward and outward during the mineralization of the breccia.

Laboratory studies have been conducted on the leaching of chalcopyrite and sphalerite with hypochlorous acid. The effects of stirring speed, temperature, pH, and hypochlorous acid concentration on the leaching rates have been determined. In addition, the leaching mechanisms have been resolved by analyzing the concentrations of the reaction products. It has been found that more than 90 pct extraction of both chalcopyrite and sphalerite can be achieved in one hour using less than 0.3 molar hypochlorous acid at room temperature. The primary leach products of chalcopyrite and sphalerite were sulfur and sulfate in the mole ratios of 1 to 1 and 2 to 1, respectively. A mixed kinetic model was applied to explain the leaching rates of chalcopyrite while a diffusion model was applied to explain the leaching rates of sphalerite. The mixed kinetic model involved steady-state diffusion of hypochlorous acid through the sulfur layer by a chemical reaction at the reaction interface. Good agreement between these models and the leaching rates of both minerals was obtained.

A direct X-ray fluorescence (XRF) method has been developed for the rapid determination of zinc, lead, iron and total sulphur present in zinc ore concentrates. The concentrations of the elements present, mainly as sphalerite, galena, pyrite and pyrrhotite, vary widely: Zn, 40–65; Pb, 0.1–10; Fe, 0.5–11; and S, 25–33%m/m. Using a wavelength-dispersive X-ray spectrometer and samples prepared as briquettes, Zn and Pb may be determined directly using the Kβ and Lγ1 lines, respectively. For Zn, a mathematical model (concentration-based correction equation) was applied to correct for inter-element effects. For the determination of Fe the ratio of the fluorescence intensities of the Fe Kα and Zn Kβ lines was used and, for the determination of total S, the intensity of the S Kα line was corrected with the Rayleigh scatter tube line, Rh Lα. For both iron and total sulphur, subsequent application of the mathematical model helped to correct for the residual inter-element effects. Good agreement was obtained between experimental and certified values for two international reference materials.

On-line X-ray fluorescence analysis is used in the mineral processing industry to monitor the composition of the solids contained in various slurry streams. This study compares wavelength dispersive and energy dispersive techniques by using a slurry recirculation system employing both an X-ray tube excitation-wavelength dispersive system, and an isotope-excitation energy dispersive system. The results showed the less costly energy dispersive system yields accurate information that can be used to control milling operations.

Microbially mediated leaching and solubilization of zinc ore concentrate by native aquatic microbial communities incubated under aerobic and oxygen‐limited conditions were examined in static microcosms consisting of stream sediment and water. Sterile controls provided information on abiotic sulfide oxidation and leaching of zinc, lead, cadmium, and copper. The flux of these heavy metals from the sediments to the water column was greatest under biotic oxygen‐limited conditions. When calculated as the percentage of total metal available in zinc concentrate‐amended microcosms, the order of metal solubilization under oxygen‐limited conditions was lead, copper, zinc, and cadmium. Under biotic aerobic conditions, the order of solubilization was zinc, lead, cadmium, and copper. This study indicates that aquatic heterotrophs are capable of leaching and solubilizing metallic sulfides under conditions of neutral to slightly acidic pH and are effective in releasing heavy metals to the water column under oxy...

Zinc calcine, cakes, waelz and fuming oxides, etc. are investigated, applying DTG and thermogravimetric analysis. X-ray phase analysis, Mossbauer spectroscope, chemical and chemical phase analysis. Their phase contents are defined. The phase ZnO. 2ZnSO 4 occurs in some semi-finished products in addition to ZnO, ZnO·Fe 2 O 3 , Zn 2 SiO 4 , ZnSO 4 , and ZnS. The obtained results are of great importance to the improvement of the indices of the technological processes in zinc production by the hydrometallurgical method.