The production of tetraamminezinc diperrhenate was studied at various concentrations of rhenium in the solution. The concentration varies from 0.025 to 0.1 mol/L. The amounts of ammonia and zinc sulfate required for the formation of [Zn(NH 3) 4](ReO 4) 2 were estimated taking rhenium concentration into consideration and the …

or rhenium with a certain concentration. 1 mol/L Nitric acid or sodium hydroxide was used to adjust the solution pH. After that, glass vials were shaken in a shaker with a constant temperature at a speed of 120 r/min for 24 h to reach equilibrium. Concentrations of uranium and rhenium were determined by bromocolorimetry and thiourea photometry

Abstract The recovery of rhenium from waste acid is an urgent issue due to low rhenium concentration and high sulfuric acidity. To solve the problem, novel coated solvent-impregnated resins consisting of inert resins LS-300, Alamine 304-1 and the PVA film (304-CSIRs) were prepared for the separation of Re(VII) from high sulfuric acid …

Use of Dowex 1X8 and AgCl Column.A Dowex 1X8 anion exchanger (Cl-form, 200–400 mesh) with a capacity of 3–5 meq/g (Sigma Chemicals) and extra pure AgCl were used in this method of postelution concentration [].Between 10 and 12 mg of Dowex 1X8 resin was taken in a 2 mL syringe and placed in a polypropylene tube (~8 mm × 1 mm) with a few …

The results of joint uranium and rhenium sorptions from the solutions with strong base anion exchange resin Ambersep A920U (herein after A920), are presented in the paper. Effect of salt form (sulfate, chloride, nitrate, hydroxide), nature of sulfate, nitrate, and chloride containing compounds (acids, their sodium and zinc salts), sodium …

1. Introduction. Rhenium was discovered in 1925 and it is considered to be an extremely rare metal with unique properties. Despite low rhenium concentration in the earth's crust of about 10 −7 %, it acquired wide industrial application [1,2].World rhenium consumption from primary sources ranges from about 50 to 60 metric tons per year [].About 70% of the …

Rhenium compounds are included in molybdenum concentrates derived from porphyry copper deposits, and rhenium is recovered as a byproduct from roasting such …

It was found that almost 100% of Re was in dissolved forms, mainly ReO4-, therefore, the Re concentration was constant from the surface to 30 m depth and ranged from 6.1-7.4 ng. kg-1.

Abstract Rhenium (Re) is a critical and extremely rare element. The unique properties of Re have enabled it a vital element in making superalloys and in petroleum …

The rhenium concentration was controlled by varying the Mo precursor flow rate. The concentration of the rhenium precursor in the form of samples with pre-deposited ReO x particles was maintained constant. This method allows for film synthesis over the large scale.

Rhenium concentrations in RMs dissolved by alkaline fusion and acid digestion methods Table 2, Table 3 list the Re values in the RMs determined by both digestion methods. The Re concentrations determined by the alkaline fusion method in igneous rock samples ranged from 0.036 to 3.9 ng g −1 which agreed well with the …

Molybdenite contains the highest concentration of rhenium, up to 1.88%. The geochemical link between rhenium and molybdenum is based on the similar radii of Re 4+ ... NH 4 ReO 4 is the most common form in which rhenium is traded. The crystal structure of cubic NH 4 ReO 4 (space group I4 1 /a, a = 587.1 pm, Z = 4) is that of …

The electroreduction mechanism of ReO 4 − in acidic solution is investigated intensively via experiments and thermodynamic analysis. High acidity and low ReO 4 − concentration are the advantageous conditions to fabricate metallic rhenium, while under other conditions only small amount of rhenium oxides can be obtained. The reduction of …

Although the DO concentrations vary significantly (2–14 mg/L), the rhenium concentrations of the Chilika show no statistically significant correlation with the DO content (r = −0.17; n = 17). This observation indicates that the redox state of the water column has a limited effect on the observed Re removal from the Chilika waters ( Fig. 4 ).

Commercially, Rhenium exists in powder form, but it can be consolidated by sintering and pressing it in a hydrogen or vacuum atmosphere. The consolidation process produces a small solid whose density is over 90% of the metal. ... The balance of these tungsten-rhenium alloys improves with an increase in rhenium concentrations, and …

Thallium (Tl) is an extremely toxic rare metal to the eco-environment. Trace thallium impurity in ammonium perrhenate is harmful to the high-temperature mechanical properties of rhenium metal used for aeroengine single crystal blade. The di(2-ethylhexyl) phosphoric acid (P204) extraction to remove thallium in ammonium perrhenate solution …

@article{osti_5535958, title = {Cermet fuel reactors}, author = {Cowan, C L and Palmer, R S and Van Hoomissen, J E and Bhattacharyya, S K and Barner, J O}, abstractNote = {Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high …

Element Rhenium (Re), Group 7, Atomic Number 75, d-block, Mass 186.207. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images. Jump to main content.

Introduction Rhenium (Re, atomic mass 186.207) is one of the least abundant chemical elements present on Earth, with concentrations in most materials ranging from 10−12 g …

Introduction. Rhenium has been widely used mainly in oil refinery industries and high temperature superalloy productions. In addition, it is one of the rarest elements in Earth's crust with an average concentration of 1 ppb, and is usually recovered from molybdenite with a rhenium concentration of 0.2% through roasting or direct reduction …

where C Re and V leaching are the concentration of rhenium and the total volume of leaching solution, respectively. M element is the mass fraction of rhenium element in the dry filter cake, and m sample represents the mass of the wet filter cake.. To optimize the leaching process, the initial copper ion concentration, solid-to-liquid ratio, …

Lead sludge from copper production is a source of rare metals, such as rhenium and osmium, whose content reaches 0.06–0.08% and 0.0025–0.0050%, respectively. The base of the sludge consists of ...

Rhenium (Re) is a trace element whose redox chemistry makes it an ideal candidate to trace a range of geochemical processes. In particular, fractionation of its …

The behavior of rhenium and iodine release was comparable within a given half-cell test. The release of iodine and rhenium at 4% moisture content initiated with an initial concentration spike in the sediment immediately contacting the concrete monolith. The concentration profile rapidly decreased to zero within the first 5 cm of the sediment ...

The abundance of rhenium (Re) in sedimentary records can inform us about the redox conditions and inputs of organic matter prevailing in modern and ancient oceans. In this contribution, spatial distributions of dissolved rhenium concentrations along the salinity gradient of a large tropical lagoon (Chilika lagoon (India), an estuary-like feature …

In the second series, the initial acid concentration was constant (0.010, 0.10 or 0.50 mol/L) and the rhenium concentration was varied between 0.33 and 32 ... It is known that rhenium forms also chloride complexes at HCl concentrations exceeding 3 ...

The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge …

In this work, the chemical and phase compositions of ternary electrolytic alloys CoWRe deposited from an acidic citrate electrolyte have been investigated as a function of current density. The obtained coatings were found to have electrocatalytic properties in the hydrogen evolution reaction (HER). In the studied range of tungsten and rhenium …

The world resources of rhenium are estimated at 11–17 kt, and the average annual production (in a form of metal and compounds) is about 35 t. The largest manufacturer is Molymet company from Chile, which produces 60% of the total world production — in a form of metallic rhenium, ammonium perrhenate and perrhenic acid …

Rhenium is most enriched in molybdenites from volcanic sublimates (23,800 ± 5 ppm), with skarn Fe and Au (560 ± 5 ppm and 540 ± 3 ppm respectively) and porphyry Cu and Cu-Au deposits next (470 ...