Barite Ore Research Articles

Assessing the geochemical and environmental baseline of heavy metals in soils around hydrothermal hematite-barite-galena veins in Baghin area, Kerman, Iran.

To assess the geochemical and environmental baseline as well as the availability of the heavy elements in soils around the hematite-barite-galena veins in the Baghin area, a total of 70 soil samples were collected and analyzed by ICP-OES for 43 heavy metals and metalloids. Compared to the global soil level or crustal abundance, the calcareous soils are 2-26 magnitudes enriched in Ca, Cu, Pb, Zn, Cd, Se, As, Sb and Sr. The ferruginous soils are highly enriched in Fe, Mo, Pb, Zn, Cd, As, Sb, Ba and Sr, almost 2-49 orders higher than the crustal abundance and global soil level. Additionally, the baritic soils are 3-94 times higher than the crustal and global soil values for Ba, Cu, Mo, Pb, Zn, Ni, Co, Cd, Se, As, Sb and Sr. However, the soils developed on the shale layers are moderately enriched in As, Zn, Se, Sb, Ba, Pb and Sr. The high concentrations of heavy metals are possibly related to the presence of minor sulfide minerals in barite-rich soils or adsorption by Fe-oxy-hydroxides formed by oxidation of sulfide minerals. Therefore, the oxidation of minor sulfide minerals in barite veins may be prone to acid mine generation and of environmental concern. The inhalation of silica dusts released by silica-rich barite ores (20% SiO2) during crushing, milling, as well as using in drilling mud may trigger silicosis. Despite the high baseline values of some heavy metals and metalloids, the presence of Fe-oxy-hydroxides and clay minerals in the soils could play significant roles in sequestering the toxic effects of heavy metals contamination in soil, groundwater, plants, wildlife and humans.

Setting, sulfur isotope variations, and metamorphism of Jurassic massiveZn‐Pb‐Agsulfide mineralization associated with arc‐type volcanism (Skra, Vardar zone, Νorthern Greece)

AbstractMassive Zn‐Pb‐Ag sulfide mineralization appears conformable with felsic volcanism, developed in an Upper Jurassic volcanic arc to the Southwest (SW) of the Serbo‐Macedonian continent in Northern Greece. The host volcanic sequence of the mineralization comprises mylonitized rhyolitic to rhyodacitic lavas, pyroclastics, quartz‐feldspar porphyries, and cherty tuffs. A “white mica—quartz—pyrite” mineral assemblage characterizes the volcanic rocks in the footwall and hanging‐wall of massive sulfide ore layers, formed as a result of greenschist‐grade regional metamorphism on “clay‐quartz‐pyrite” hydrothermal alteration haloes. Massive ore lenses are usually underlain by deformed Cu‐pyrite and quartz‐pyrite stockworks. Most of the sulfide ore bodies have proximal‐type features. Ductile deformation and regional metamorphism have transformed many of the stockwork structures. The mineralization is characterized by high Zn, Pb, and Ag contents, while Cu and critical metals are low. Primary depositional textures, for example, layering, clastic pyrite, colloform, and atoll textures were identified. The overall textural features of the mineralization indicate it has undergone mechanical deformation. The most prominent features of the effects of metamorphism, folding and shearing, are modification of the ore body morphology toward flattened and boudinage structures and transformation of the ore textures toward the dominance of planar fabrics. Sulfur isotope analyses of sulfides along with textural observations are consistent with a dual source of sulfide sulfur. Sulfur isotope values for sphalerite, non‐colloform pyrite, galena, and chalcopyrite fall in a limited range from −1.6 to +4.8‰ (mean δ34S + 2‰), indicating a hydrothermal source derived from the reduction of coeval seawater sulfate in the convective system. Pyrites with colloform and atoll textures are characterized by a34S depletion, indicating a bacterial reduction of coeval seawater sulfate. The morphology of ore beds, the mineralogy, sulfide textures, and ore chemistry along with the petrology and tectonic setting of the host rocks can be attributed to typical of a bimodal‐felsic metallogenesis. Although similar in many respects to classic Kuroko‐type volcanogenic massive sulfide mineralization, it has some atypical features, like the absence of barite ore, which is possibly a result of significant temporal depletion in sulfate due to bacterial reduction, a conclusion supported by the widespread occurrence of colloidal and atoll textures of pyrite.

Preparation of Barium Titanate from Barite Ore of Andhra Pradesh

Barium titanate (BaTiO3) is an attractive material in the field of electro ceramics and microelectronics due to its better characteristics. It is having high dielectric constant and low loss characteristics and hence barium titanate is an excellent choice for many applications, such as capacitors, multilayer capacitors (MLCs) and energy storage devices. In the present study an attempt is made to prepare barium titanate from ore using reduction ,leaching ,precipitation and calcinations techniques. The material is giving higher dielectric constant compared to the synthetically prepared materials.

Comparison of Nigerian Barite Production with some Top Barite Producing Countries

Barite is a very important industrial minerals used as weighting material in the petroleum industry. The nature of barite ores, geology of barite ores based on location were discussed. This paper presents top barite producing countries in the world, their production and consumption of barite, as well as their reserve. Despite all the barite deposits in Nigeria, which is approximately 15 million tonnes, it still imports barite from other countries for use in the drilling of oil and gas in Nigeria. This of course brings about unnecessary expenses been incurred by the government of Nigeria. Some of the challenges faced with the mining and processing of the Nigerian Barite were discussed. Proposed solutions to the mentioned challenges were also stated. The main challenge of the Nigerian barite is not with the American Petroleum Institute (API) standard, but the policies which do not favour investors. Investment by private companies into the mineral sector of Nigeria will bring about a lot of revenue to the government, if the right things are set in place. Keywords— Barite, producing countries, low-grade

Geology, isotope geochemistry, and fluid inclusion investigation of the Robat Zn-Pb-Ba deposit, Malayer-Esfahan metallogenic belt, southwestern Iran

The Robat Zn-Pb-Ba deposit in the Arak mining district in the Malayer-Esfahan metallogenic belt (MEMB) has an estimated reserve of 5 million tonnes (Mt) ore grading 2.1 wt% Zn and 1.4 wt% Pb and 4 Mt barite ore. This deposit, hosted by Early Cretaceous carbonate rocks, formed in an extensional back-arc environment between the Sanandaj-Sirjan Zone and Central Iranian Microcontinent. Sulfide and barite ores display a strong lithological control and form stratabound stacked ore lenses, which are hosted in two horizons by silicified and dolomitized limestone. They are generally best developed below marl layers within intercalated shale, marl, and limestone.The textural and mineralogical data indicate two main stages of sulfide and barite mineralization at the Robat deposit. The first stage comprised deposition of volumetrically minor early fine-grained disseminated sulfides and barite near the seafloor in unconsolidated sediments. Subsequently, sub-seafloor replacement of barite, carbonate, and early sulfide laminae/bands occurred by precipitation of late sulfides and other hydrothermal minerals within the Early Cretaceous limestone-dominant sequence. The minerals in this later stage were deposited in a close relationship with quartz veins.Electron microprobe analyses revealed that sphalerite has a very high Fe content averaging about 1.23 wt% and is relatively enriched in As, Ga, Ge, Cd, Ag, and Bi, which is similar to Irish-type carbonate-hosted deposits. In addition, the Ag content of galena is comparatively low, although concentrations of Ga, Ge, Cd, Zn, and Sb are fairly high. Fluid inclusion microthermometric study of hydrothermal quartz revealed two types of primary two-phase (L + V) fluid inclusions in hydrothermal quartz. Type I fluid inclusions with irregular shapes were recorded along crystal growth zones, whereas type II inclusions are observed as isolated inclusions with relatively regular shapes that are less common than type I. Type I and II inclusions exhibit homogenization temperatures of 140–239 °C and 233–290 °C, with salinities of 2.2–11.8 and 5.5–11.5 wt% NaCl equiv., respectively. Fluid inclusions extracted from quartz displayed δDSMOW between −67‰ and −56‰ and measurements of hydrothermal quartz yielded δ18Ofluid (SMOW) of 12.9‰ to 23.5‰. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios of galena samples fell in the ranges of 18.412–18.427, 15.642–15.647, and 38.556–38.580, respectively. The different ratios for the Pb isotopes suggest a dominant continental crust origin for Pb in the ores. Geological, textural, mineralogical, and isotopic data may be cumulatively interpreted to indicate that the Robat carbonate-hosted deposit formed from sub-seafloor replacement like commonly observed for Irish-type base metal deposits.

Microthermometric evidence for the formation of Permian VHMS deposits in Tasik Chini area, Central Belt of Peninsular Malaysia

The VHMS deposits of Tasik Chini area are located in the Pahang State of Central Belt, Peninsular Malaysia. The deposits occur in a package of Permian volcanics within mixed volcano-sedimentary sequence, and have been exploited from the Bukit Botol and Bukit Ketaya deposits. They have many similarities with Kuroko-style massive sulfide deposits. The host rocks at both deposits are felsic volcanic rocks of rhyolitic to rhyodacitic composition. Mineralization occurs as distinct ore zonation forming a stringer to massive sulfide zone at the footwall followed by barite lenses and exhalite layers (Fe + Mn ± Si ore) at the stratigraphic top. The sulfide phases are characterized by pyrite as the major sulfide mineral, with subordinate chalcopyrite, sphalerite and rare galena; traces of gold, silver- and Sn-bearing minerals occur in the massive sulfide and barite ores. Primary fluid inclusions within quartz and barite occur as two types: (1) type I: two phase, liquid-vapour inclusions without daughter minerals, and (2) type II: three phase, liquid CO2-bearing carbonic inclusions. These three phase inclusions include liquid H2O, liquid CO2 and vapour CO2, with variable CO2 content, and often decrepitate before complete homogenization. Microthermometric measurements of the type I inclusions show that the temperature of homogenization (Th) varies between 180 °C and 310 °C with salinities ranging from 1.0 to 15.0 wt% NaCl equivalent in the quartz samples. Homogenization temperatures (Th) of 190 °C to 300 °C and salinities between 1.0 and 13.0 wt% NaCl equivalent are recorded from the barite samples. Type II inclusions have an initial melting temperature range of −57.1 °C to −57.5 °C, clathrate melting temperature (Tmclathrate) of 7.4 °C to 8.0 °C and CO2 homogenization temperature (ThCO2) between 30.1 °C and 30.3 °C, and salinity ranging from 4.0 to 5.1 wt% NaCl equivalent. Densities, pressure and depth of ore forming fluids range from 0.711 to 0.970 g/cm3, 12 to 93 bars, and ∼1500 m depth of seawater. Laser Raman spectroscopic analysis shows the presence of CO2 in the carbonic inclusions. The fluid inclusion results suggest that the main ore fluid during the formation of the Tasik Chini VHMS deposit is a seawater-dominated fluid, but contribution from a modified seawater or possibly magmatic origin is also indicated by higher salinities relative to seawater (3.2 wt% NaCl) and the presence of CO2. Taking into account the regional geodynamic evolution, it is also concluded that the formation of VHMS deposits in the Tasik Chini area occurred in a back-arc geotectonic setting.

Beneficiation of Barite Ore from Azara in Nassarawa State, Nigeria, using froth flotation

Barite ore from Azara in Nassarawa State has been beneficiated using Jigging and Froth Flotation techniques by varying the pH of the solution. The chemical analysis indicates the presence of major elements Ba, S, O and minor elements like Ti, V, Al and Si which confirms that it is barite while the particle size analysis showed that the average particle size is ≈ 150 μm with a 1,167 cm 2 /g specific surface area. The X-ray diffraction analysis of both the as-mined ore and beneficiated samples indicate increased intensity in the later. The jigging result shows that 51% of the feed is the underflow while 46.7% is the overflow. The measured specific gravity as a function of pH show that values between 3.78 and 4.23 are obtained. The elemental composition of the Barite after beneficiation shows that in addition to high contents of BaO and SO 3 , the amount of SiO 2 present is still very high. The sample with a pH value of 7 gave the highest specific-gravity value of 4.23 while that with pH of 3 gave the lowest specific-gravity value of 3.78. The implication is that the barite sample with pH of 7 is acceptable for oil and gas applications while more work is needed for samples with other pH values. Keywords: Barite ore, Froth flotation, Specific gravity, Beneficiation, pH, Jigging

Beneficiation of Azara Barite ore using a combination of jigging, froth flotation and leaching

In this research, Jigging, Froth Flotation and leaching have been used to beneficiate barite ore from Azara, Nasarawa State Nigeria. Chemical analysis on the ore indicates that it contains 53.09% of Ba and 11.52% S with a specific gravity value of 3.207±0.03. After the jigging operation, the specific gravity values of the underflow and overflow are 3.77±0.029 and 2.77±0.058 respectively while the Ba and S increased to 78.61% and 15.87% respectively. After the froth-flotation, the specific gravity values obtained are 3.95, 4.1 and 4.05 corresponding to pH values of 5, 7 and 9 respectively. Frothed barite with pH of 7 was leached with 0.2M HCl and a mixture of 0.2M HCl and HOCl. After leaching, the specific gravity values are 4.38±0.03 and 4.27±0.02 for HCl and HCl+HOCl respectively. The X-ray diffraction patterns show that highly crystalline peaks are obtained after froth flotation while more phases are added with leaching.Keywords: Barite; Jigging; Froth Flotation; Leaching; Specific gravity

The genesis of the Dahebian Zn-Pb deposit and associated barite mineralization: Implications for hydrothermal fluid venting events along the Nanhua Basin, South China

The Dahebian stratiform barite deposit, which is situated in the Nanhua Basin, is one of the world’s largest and most important barite deposits. This deposit was formed through sedimentary exhalative processes in the early Cambrian stage. Recently, beneath stratiform barite ore, stratabound Zn-Pb-(Fe-bearing) sulfide mineralization, which is hosted by the Doushantuo Formation, was discovered. Ores that represent Zn-Pb sulfide mineralization are mainly discordant but stratabound. The Doushantuo Formation consists of laminated interbedded layers of micritic dolomite and carbonaceous mudstone, associated with phosphorite and chert. The sulfide ores consist primarily of sphalerite, pyrite and galena. The associated gangue minerals are barite, quartz, minor calcite, as well as trace amounts of apatite and hyalophane. Hyalophane found in the stratiform barite ore is richer in barium but poorer in potassium than that associated with the sulfide ores. This outcome corresponds to ascending hydrothermal fluids that are richer in barium along with sulfide mineralization. Investigation of the ore fluid reveals relatively high temperature (142–368 °C) with scattered salinity (0.53–25.62 wt% NaCl eq.). This finding suggests that fluid cooling and/or mixing with seawater could be the primary mechanisms that prompted the ore formation. Sulfides selected from the zinc-lead sulfide ores and stratiform barite ore have similar sulfur isotopic compositions, with δ34S values ranging from 13.5‰ to 30.0‰; δ34S values of barite from these ores are analogous, with δ34S values ranging from 29.5‰ to 55.1‰. The sulfur isotopic fractionation between minerals (barite and sulfide) and the early Cambrian seawater is ΔBarite-Seawater = 7.8‰ and ΔSulfide-Seawater = −12.1‰, respectively, demonstrating that the sulfur in the Dahebian zinc-lead deposit and the stratiform barite deposit were derived from the early Cambrian stratified seawater column. Lead isotopic compositions of sulfide ores indicate that these ore metals are mainly sourced from rocks of the Doushantuo Formation and the underlying fold basement.Therefore, the Dahebian zinc-lead deposit and stratiform barite deposit probably arose from Selwyn-Type sedimentary exhalative hydrothermal fluids. Zn-Pb sulfides were mineralized in the feeder zone of these hydrothermal fluids, and the stratiform barite ore deposits represent the upper sedimentary-exhalative mineralization. This finding points to intensive Zn-Pb-Fe-Ba hydrothermal fluid venting into the Nanhua Basin and to relatively oxic deep ocean waters during the early Cambrian.

Textures and trace element composition of pyrite from the Bukit Botol volcanic-hosted massive sulphide deposit, Peninsular Malaysia

The Bukit Botol volcanic-hosted massive sulphide (VHMS) deposit is located in the Central Belt of Peninsular Malaysia. The deposit occurs in a package of Permian-aged coherent felsic volcanic and volcaniclastic rocks which have a geochemical signature indicative of a volcanic arc tectonic setting. Mineralisation shows distinct ore zonation, forming a stringer to massive sulphide zone at the footwall followed by barite lenses and exhalite layers (Fe-Mn ore) at the top. Mineralogy is characterised by pyrite as the major sulphide mineral, with minor chalcopyrite, sphalerite, and rare galena; traces of gold, silver- and tin-bearing minerals also occur in the massive sulphide and barite ores. Laser ablation inductively coupled plasma mass spectrometry (LA−ICP−MS) analysis combined with the textural characteristics of pyrite provides evidence for significant variations of trace elements in different pyrite types at Bukit Botol, having three types of pyrite in the paragenetic sequence. The concentrations of As, Se, Te, Cu, Zn and Pb decrease from the early pyrite 1 to the late stage pyrite 3, and the Co/Ni ratios vary for the three pyrite types. The combined textural and compositional data of pyrite suggest that the hydrothermal fluid responsible for mineralisation evolved from an early, high temperature, reduced, low pH and desulphurized fluid to more S-rich, oxidized, high pH and cooler fluid. Available sulphur isotope data from the Bukit Botol deposit point to reduced seawater, along with a possible magmatic contribution, as the most probable sources for the ore-forming fluids.

Experimental modeling for upgrading of brown barite ore by different processing methods

Barite powder as a weighting agent is the most important additive into drilling mud for the oil and gas extraction. In this study, production of brown barite powder (SG 4.065 g/cm3) was examined by flotation (direct and reverse) and magnetic separation for upgrading the quality of fine barite particles and receive it to the standard point for drilling applications (SG higher than 4.2 g/cm3). Mineralogy analysis showed that hematite was the main associated mineral, and particles were liberated below 200 µm. Thus wet high intensity magnetic separator (WHIMS) was used and results indicated that WHIMS could increase the quality of product to SG ~ 4.2 g/cm3. However, flotation separation was examined for the possible improvement in quality of the product. The Taguchi experimental modeling method was applied to scheme flotation tests, compute the various values of flotation parameters for upgrading the SG of products and determine their optimal values. Outcomes demonstrated that flotation can provide higher quality for products than WHIMS, S.G: 4.44 and 4.35 g/cm3 in direct and reverse flotation, respectively. Results indicated that Taguchi method can successfully be used for design of experiments in the manufacturing process; reduce risks and costs of industrial development. These outcomes illustrated that the Mehdiabad brown barite ore can be upgraded by direct flotation and meet the required quality for drilling.

Designing different beneficiation techniques by Taguchi method for upgrading Mehdi-Abad white barite ore

ABSTRACTGravity separation (jigging) and flotation were used to upgrade barite ore from the under developed Mehdi-Abad deposit with general specific gravity (S.G) 3.59 gr/cm3. Jigging experiments on coarse particles did not indicate significant upgrading (S.G 3.94 gr/cm3 and recovery 90%) where barite particles are mainly liberated in fine size fractions (-175µm). Optimized flotation parameters were selected based on results of designed experiments: Na-dodecylsulphate (collector) 750 g/t, sodium silicate (depressant) 2000 g/t, pH 9, size -106+63µm, conditioning time 4 min. Results of flotation tests based on optimized parameters (S.G 4.31 gr/cm3, recovery 94%) showed substantial improvement in comparison with jigging results.

Geological and geochemical constraints on the origin of the Early Cambrian Kalaizi Fe–Ba deposit in Western Kunlun, NW China

The Kalaizi deposit in the Bulunkuole Group of Taxkorgan area, Western Kunlun (NW China) is a unique regional Fe–Ba deposit accompanied with sporadic Fe–Pb–Zn sulfide mineralization within a series of iron deposits. All the ore bodies are stratabound and hosted by the Early Cambrian metamorphosed argillaceous clastic rocks. Here, we analyzed C–S–O–Sr isotopes and trace elements in individual minerals (e.g., magnetite, barite, ankerite) from the Kalaizi deposit to investigate the origin of this deposit for the first time. The S isotope fractionation (average of 21‰) between sulfate and sulfide minerals provided clear evidence that the deposit was formed in a semi-closed marine depositional environment with moderate replenishment of seawater sulfate. The distinct Post-Archean Australian Shale (PAAS)-normalized positive Eu anomalies (2.02–11.03) and lower Y/Ho ratios (27.2–33.4) relative to modern seawater in all individual magnetite minerals separated from magnetite–barite ores and the δ18O isotope signatures (10.0–13.0‰) in individual sulfate minerals suggested that hydrothermal activity played an important role in the formation of the deposit. Barium was likely derived from the dissolution of marine barite with a contribution from more radiogenic terrigenous sediments considering the slight deviations (within ±0.0013) of 87Sr/86Sr ratios of Kalaizi barites from the Early Cambrian seawater. The sulfate and sulfide minerals in the ore deposit should evolve from coeval seawater containing residual SO42− and resultant H2S by means of bacterial sulfate reduction process because (i) δ34S values (37.8–42.8‰) of anhydrite and barite minerals were slightly higher than those of penecontemporaneous seawater, (ii) pyrite and galena minerals owned δ34S values (16.3–23.5‰) were lower than coeval seawater, and (iii) 13C isotope values (−10.0 to −12.1‰) of single ankerite minerals were depleted. To summarize, the Kalaizi bedded Fe–Ba deposit is interpreted as a cold seep barite deposit overprinted by hydrothermal fluids.

Numerical Simulation of Shielding Performance of Different Aggregate Concrete

The shielding properties of different energy (1MeV, 2MeV, 3MeV) γ-rays were studied for the concrete with magnetite, magnetite ore, barite, barite ore, steel ball, ordinary sand and crushed stone as aggregates. Based on MCNP5 program, the shielding performance of different aggregate concrete was simulated and analyzed, and the attenuation coefficients, transmittance and transmission spectrum of the three-rays concrete through different aggregate concrete were obtained. Research indicates：For the same energy γ-rays, the shielding effect of concrete with steel ball, magnetite ore and magnetite as the aggregate is the best, and the shielding effect of the concrete decreases with the increase of γ-rays energy. And the transmittance of γ-rays of the same aggregate concrete is different; when γ-rays energy is higher than 1.02MeV, from the transmission spectrum can be seen, γ-rays and concrete electron-pair effect and the Compton effect probability increases

Statistical Assessment of the Microstructure of Barite Aggregate from Different Deposits Using X-Ray Microtomography and Optical Microscopy

AbstractTwo different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions’ distribution and to present the important differences of the barite aggregate specimens microstructure.

Beneficiation Study on Barite Ore of Duddar Area, District Lasbela, Balochistan Province, Pakistan

This study highlights the results of processing an indigenous low to medium grade barite oreof Duddar area, district Lasbela, Balochistan, Pakistan. The ore was characterized by x-ray diffractiontechnique. The gravity concentration and forth flotation technologies were employed to beneficiate theore in order to achieve commercial grade barite concentrate with economical recovery. The results showedthat flotation was the better method than gravity concentration to concentrate the barite mineral. A processflow sheet was designed in the light of these experiments. The flotation tests revealed that barite concentrateassaying 95.85% BaSO4 could be obtained with recovery of 82.06% from an ore containing 76.04% BaSO4.The flotation concentrate was leached to get rid of objectionable impurities. The final leached bariteconcentrate possesses 98.86% BaSO4 content and conforms to the specifications of industrial grade bariteconcentrate.

Kinetics of barite reduction from refractory barite-sulphide ore

Refractory sulphide–barite ore was reduced with carbon in order to release lead, zinc, and copper sulphide from barite-pyrite base. Mineralogical investigations showed that due to the complex structural-textural relationships of lead, copper and zinc minerals with gangue minerals, it is not possible to enrich the ore using the conventional methods of mineral processing. The influence of temperature and time was studied to optimize the conditions, and to determine the kinetics of the barite reduction. The maximum removal of barite from ore was 96.7% at 900oC after 180 min. Chemically controlled kinetic model showed the best compliance with the experimental data. An activation energy of 142 kJ/mol was found.

Mineralogy, Geochemistry and Fluid Inclusion Data from the Tumanpınarı Volcanic Rock-Hosted Fe-Mn-Ba Deposit, Balıkesir-Dursunbey, Turkey

The Tumanpınarı mineralization is a volcanic rock-hosted epithermal Fe-Mn-Ba deposit located in the southwestern part of Dursunbey, Balıkesir, Turkey. The deposit constitutes one of the most important deposits of the Havran-Dursunbey metallogenic sub-province in which numerous Early Miocene Fe-Mn-Ba deposits are distributed. The ore occurs as open-space fillings in faults, fractures, and breccias in the andesite. Early hydrothermal activity was responsible for four types of hypogene alteration in decreasing intensity: silicification, sericitization, hematization and argillic alteration. The mineral assemblage includes pyrolusite, psilomelane, hematite, and barite as well as minor magnetite, manganite, poliannite, limonite, braunite, bixbyite, galena, pyrite, and goethite. Mineralogically, three ore types are recognized as pyrolusite + psilomelane + hematite + barite ore, pyrolusite + psilomelane + poliannite ore and barite + pyrolusite + psilomelane + hematite ore (barite-dominant ore). In addition to Fe, Mn and Ba, the ore contains substantial quantities of Pb, Zn, As. Chemically, the transition from fresh to altered rocks has little effect on the elemental levels for Si, Al, Fe, Ca, Mg, K, Rb, Sr and H2O. The homogenization temperature of fluid inclusions hosted in the main stage quartz and barite ranged from 113 to 410 °C with salinities ranging from 0.4 to 14.9 eq. wt % NaCl, respectively. Overall, the available data suggest that the deposits formed as the result of the interaction of two aqueous fluids: a higher-salinity fluid (probably magmatic) and a dilute meteoric fluid.

The vein-type barite mineralization of the Draïssa ore field, Ougarta; SW- Algeria: mineralogy, trace elements and halogens

The Draissa barite vein system in the Ougarta district is located in southwestern Algeria. It is the principal mineral deposit of economic interest of the area. The mineralization is hosted by Cambrian sedimentary rocks that unconformably overlie Precambrian formations. The mineralized structures consist mostly of barite and quartz with minor sulfide minerals and trend dominantly NE-SW, NW-SE, and E-W. Siliceous alteration zones are associated with the vein system. Samples of barite ore are characterized by low total REE contents ranging from 9 to 50 ppm and positive Eu (2–2.15 ppm) and Y (1.2–11.1 ppm) anomalies, indicating hydrothermal activity during mineralization. Halogen data of the barite show that the Cl/Br molar ratio is 189:571 and the Na/Br ratio is 34:376, indicating that the sulfur was derived from seawater. The Ba-enrichment trend in the volcanic rocks of Draissa is interpreted as possible probable source of the Ba (424–3039 ppm Ba). It appears that the barite-quartz deposits were formed in two stages. Endogenous fluids deposited the primary vein materials, consisting of quartz associated with copper sulfides. Exogenous fluids (cold seawater) became heated during ascendant fluid movement. Mineralization was governed by convective motions and the barite and galena fillings were deposited in openings created by normal faulting.

Cost-effective integrated strategy for the fabrication of hard-magnet barium hexaferrite powders from low-grade barite ore

Ultrafine barium hexaferrite (BaFe12O19) powders were synthesized from the metallurgical extracts of low-grade Egyptian barite ore via a co-precipitation route. Hydrometallurgical treatment of barite ore was systematically studied to achieve the maximum dissolution efficiency of Fe (~99.7%) under the optimum conditions. The hexaferrite precursors were obtained by the co-precipitation of BaS produced by the reduction of barite ore with carbon at 1273 K and then dissolved in diluted HCl and FeCl3 solution at pH 10 using NaOH as a base; the product was then annealed at 1273 K in an open atmosphere. The effect of Fe3+/Ba2+ molar ratio and the addition of hydrogen peroxide (H2O2) on the phase structure, crystallite size, morphology, and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. Single-phase BaFe12O19 powder was obtained at an Fe3+/Ba2+ molar ratio of 8.00. The formed powders exhibited a hexagonal platelet-like structure. Good maximum magnetization (48.3 A·m2·kg–1) was achieved in the material prepared at an Fe3+/Ba2+ molar ratio of 8.0 in the presence of 5% H2O2 as an oxidizer and at 1273 K because of the formation of a uniform, hexagonal-shaped structure.