Therefore, the process for the capture of uranium from other more abundant metal ions requires high affinity, selectivity and the ability to deal with an enormous volume of water. Various techniques have been studied and developed for the extraction of uranium from seawater 5,6,7,8,9,10,11,12,13,14,15.
Through experiments, the optimized leaching conditions for this uranium ore are: sulfuric acid dosage of 32kg t –1, particle size of − 100mesh, liquid–solid ratio of 1:1, temperature of 50 °C, oxidant of 10 kg t –1 manganese dioxide, stirring leaching for 8 h, with a stirring intensity of 150 rpm. Under these conditions, the leaching ...
The results from our institute and other early marine tests for the extraction of uranium have shown that fairly quantities of manganese were sorbed onto amidoxime-functionalized polymers 35,36.
Dissolution of uranium is the first hydrometallurgical process in the extraction of uranium from the uranium containing minerals in the ore. Leaching procedures selected for dissolving ... Following is a discussion of each of the oxidants typically used in acid leaching of uranium. Manganese dioxide (MnO 2) This is the traditional oxidant used ...
This is avoided by adding a secondary, strong oxidising agent such as hydrogen peroxide or manganese dioxide, which are considered one of the major costs associated with this process (Muñoz et al., 1995).
In the uranium mining industry, ore containing uranium is first leached to dissolve out the uranium . The leaching process can be done under acidic or alkaline conditions, and uses the solubility of uranium ... Common oxidants are iron, manganese dioxide (MnO 2), and hydrogen peroxide (H 2 O 2) [13, 14].
A hydrometallurgical process is used to produce uranium from uranium ore, using chemicals and solutions to extract the uranium from the ore matrix. The process is complete when the final uranium product, known as yellowcake, is produced in a sufficient high purity (typically 75 to 85 percent U 3 O 8 ) so that it can be used in the …
In the acidic leaching uranium process, pyrolusite or manganese oxide (MnO2) powder is often used as an oxidizer. In the processed effluent, manganese ion present as a contaminant in addition to U, Ra, Th, As, Zn, Cu, F, SO4 2-, etc. Manganese ion content is about 100~200 mg/1 in effluent. In this case, a new process technique
Solid sulfur (powder) with a purity greater than 99.99 wt% was used as a reducing agent for investigating the reaction mechanism of manganese dioxide. Sulfur waste, obtained from an oxygen pressure …
The ore grade of manganese can be classified as manganese dioxide ore or depending on the manganese content in the ore. ... Life cycle assessment is a widely used tool to assess and quantify the environmental effects from a mining process or a system of processes (Norgate et al., 2007; Nuss and Eckelman, 2014; Stewart and …
For the calcification roasting process with n(CaO)/n(V 2 O 3) of 2, the leaching rate of manganese decreases gradually with the increase of m(MnO)/m(V 2 O 3), which shows that manganese plays the smaller role in the process of vanadium extraction due to the introduction of calcium salt. Furthermore, once the amount of calcium salt …
Temperature has a significant impact on the adsorption of + UO 2 2 over the GO surfaces. Some studies reported a favorable adsorption process at elevated temperature, i.e., the amount of the ...
used is manganese dioxide. The stages in the leaching process at which the different reagents are added varies from mine to mine. The effects of these two reagents on the extraction of uranium are shown in Figs. 1 (for manganese dioxide) and 2 (for acid). Both figures show an initial steep rise in extraction as the reagents are added. Above an ...
Important amounts of uranium (U(VI)) derived from mining, milling, and enriching activities were released into environment, and were potentially becoming a common toxic radioactive contaminant to aquatic organism and human health [1, 2].An maximum amount of 9 and 20 μg L −1 of U(VI) concentration in drinking waters and …
A manganese dioxide coprecipitation procedure is utilized to replace a time-consuming evaporation step for the extraction of thorium, uranium and cerium from freshwater samples. The average recovery for 20-liter samples is greater than 95% for234Th and144Ce. The data indicate that the manganese dioxide coprecipitation process does …
The mechanism of precipitation-air aeration-hydrated manganese hydroxide adsorption takes advantage of the Mn2+ ion in uranium effluent to treat the effluent, i.e. waste …
The chemistry of the leaching process revolves around the oxidation of the Uranium compounds, which is achieved due to Manganese dioxide, Sodium Chlorate, and Iron salts. The reaction is typically …
The New Uranium Mining Boom: Challenges and Lessons Learned; Springer: Berlin/Heidelberg, Germany, 2011; Part 3; pp. 433–442. ISBN 978-3-642-22121-7. [Google Scholar] Patel, R.; Clifford, D. Radium Removal from Water by Manganese Dioxide Adsorption and Diatomaceous-Earth Filtration Final Report (PB--92 …
Uranium Mining Ef-fluent by a ... The < 0.125 mm fraction of manganese dioxide black powder (Carlo Erba, BET surface area: 4 m 2 g −1 ), MDBP, was selected for Ra adsorption experiments ...
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WEBas manganese dioxide or sodium chlorate has to be added to achieve satisfactory uranium extraction. The oxidant is needed because most ores contain uranium in the …
Manganese dioxide ore is delivered to the harbour in Walvis Bay by ship and then railed to site and stored in a storage bunker. It is transported by front end loader to a crushing, grinding and thickening plant adjacent to the leach modules where a finely ground slurry is produced and delivered to the leach tanks as part of the extraction process.
In present paper, delta manganese dioxide is prepared with a hydrothermal method, and the adsorption is investigated with a batch method. The maximum sorption capacity for uranium and lead are calculated to be 41.32 and 492.61 mg g−1 respectively. Pseudo-second-order kinetic is proved to regulate the sorption kinetics, and Langmuir …
The optimum conditions for the extraction of cadmium were found to be 30 min of static extraction followed by 30 min of dynamic extraction, a temperature of 323 K, a pressure of 20.27 MPa, a CO 2 ...
The first phase of this study was conducted to examine the feasibility of extracting manganese from Georgia umber ore by means of a three-stage continuous sulfuric acid-ferrous sulfate pickle liquor leaching …
There are about ~15% of equilibrium manganese complex with the ligand in seawater pH(8.3), indicating that manganese could compete to some degree with uranium for sorption sites.
The adsorption process followed the pseudosecondary kinetics and Langmuir models. The maximum U(VI) adsorption capacity of the GONRs/CTS composite membrane was calculated to be 320 mg∙g−1. Hence, the GONRs/CTS composite membrane prepared in this study was found to be suitable for separating and recovering …
This paper will address the life-cycle environmental-impact assessment for three different mining process of uranium extraction: open-pit, underground, and in-situ …
They were able to show that this process matched the extraction efficiency of lithium, nickel, cobalt and manganese to 90% when compared to the conventional leaching processes, while also using ...
Underground mining holds the second position overall while the most sustainable uranium extraction process identified is open-pit mining. The reason behind this result is the radon-222 emission from underground mining, which is 1000000 kBq, while from open-pit mining radon-222 emission is 13000 kBq and from in-situ leaching, it …
To date, various nanomaterials, such as metal oxide nanoparticles, carbon nanotubes, and graphene oxides, have been used for adsorbing uranium from aqueous solutions (e.g., Zahran et al., 2019).