Acid dissolution of neodymium magnet Nd-Fe-B in different conditions

The separation of rare-earth elements (REE) from a neodymium magnet has been widely studied last year. During the research it was identified that the waste of computer hard disk contains 25.41 % neodymium, 64.09 % iron, and <<1 % boron. To further isolate rare-earth metals, the magnet was acidically dissolved in open and closed systems. In both methods of dissolution, concentrated nitric acid was used. The difference between these methods is the conditions of dissolution of magnet. The magnet was dissolved in a microwave sample preparation system at different temperatures and pressures in a closed system. In the open system, the acid dissolution of the magnet is conducted at room temperature. 0.2 g of the neodymium magnet sample was taken under two conditions, and the dissolution process in the closed system lasted 1 hour, and in the open system 30-40 minutes. The open system is a non-laborious, simple, and cheap method of dissolving the magnet by comparing both systems. Therefore, an open sample preparation system is used for further work. To remove the iron in the magnet, oxalic acid was used and REEs are precipitated as oxalates under both conditions. According to the result of the Inductively coupled plasma mass spectrometry (ICP-MS) method, it was identified that the neodymium and iron contents in the precipitate are 24.66 % and 0.06 %, respectively. This shows that the iron has almost completely passed to the filtrate

Influence of alkaline pre-treatment on acid dissolution of cathode material of 18650 lithium battery

Lithium battery cathodes contain lithium, cobalt, nickel, and manganese. Recycling of spent lithium batteries aims to recover these elements for re-use. Liberation of cathode materials from other metals in the battery such as aluminium, copper, and iron, is essential to obtain a good leaching efficiency in the recovery of valuable metals from end-of-life lithium batteries. This study investigates the behaviour of cathode materials and other metals in spent 18650 lithium batteries during leaching in H2SO4 solution with and without NaOH pre-treatment. Dissolution of aluminium using NaOH is a selective method to separate the metal from other elements. The influence of a 2-hour NaOH pre-treatment on subsequent acid leaching of cathode materials was investigated at both room temperature and 80°C. The extraction of aluminium increased to 75% at a higher temperature. Lithium concentration in the pregnant leach solution from acid leaching also increases with NaOH pre-treatment. The pre-treatment had a negligible effect on nickel, manganese, iron, and copper extraction. However, the cobalt extraction with NaOH pre-treatment was significantly lower. The result was likely due to indirect impact of less hydrogen gas was generated from a lower Al amount. The lattice structure of the leach residue for the sample with NaOH pre-treatment was monoclinic rather than rhombohedral due to stronger delithiation.

Acid dissolution behavior of ferritic FeCrAl tubes candidates for nuclear fuel cladding.

The international materials community is engaged in finding safer alternatives to zirconium alloys for the cladding of fuel in light water reactors. One solution is to replace the zirconium cladding using ferritic iron-chromium-aluminum -FeCrAl- alloys, which offer extraordinary resistance to high temperature reaction with air or steam due to the formation of a protective alumina layer on the external surface. It is important to characterize the behavior of FeCrAl not only during accident conditions but in the entire fuel cycle, which may include reprocessing of the used fuel after it is removed from the power reactors. The reprocessing may involve the dissolution of the fuel rods in mineral acids. Little or nothing is known on the dissolution of FeCrAl alloys in common mineral acids, therefore the objective of this research was to study the dissolution of typical cladding tubing having two compositions of FeCrAl (APMT & C26M) in three acids (H2SO4, HNO3 & HCl) as a function of the temperature using both standard ASTM immersion tests as well as electrochemical tests. The dissolution behavior of the FeCrAl alloys is compared to the dissolution capability of other traditional nuclear materials such as austenitic stainless steels (304SS & 316SS) and austenitic nickel alloys (Alloy 600 and Hastelloy C-276). Results show that both C26M and APMT have a higher dissolution capability in the studied mineral acids, which will be beneficial for reprocessing procedures.

Determination of Carbonate Concentrations in Calcareous Soils with Common Vinegar Test

Calcareous soils are those that have free calcium carbonate (CaCO3) and have pH values in the range of 7.0 to 8.3. If they are managed properly, calcareous soils can be used to grow any crop. Before employing any management practices, it is important to know how much carbonate exists in the soil. Soil carbonate is usually quantified by acid dissolution followed by the volumetric analysis of the released carbon dioxide (CO2). In geological sciences, a simple acid test consists of placing a drop of dilute hydrochloric acid on a rock or mineral and observing if there are CO2 bubbles released; the bubbles indicate the presence of carbonate minerals. The household test below uses vinegar and other simple instruments to estimate soil carbonate concentration. Minor revision with an added author.

Integrated Workflow with Experimentation, Modeling, and Field Studies Enhances Fracture Diversion Design in Carbonate Reservoirs

Multiple near-wellbore diverters and their applications exist in the industry. However, understanding of their effectiveness in carbonate acid fracturing applications still has unanswered questions, mainly due to the lack of knowledge on how the fracture width develops at entry points with continuous acid dissolution. This continuum needs to be understood through integrated modeling and experimentation at the yard-scale, and field-scale perspectives. An advanced numerical model was used to analyze the width development in varying calcite/dolomite fractions and acid concentrations. A robust diversion pill was developed during extensive testing, and its performance was validated in the laboratory using a slot test. The goal was to create a system with reliable bridging ability and low permeability to ensure isolation. Multimodal particles help to ensure effective bridging and plug stability. A similar bridging test was conducted at the yard scale with a small pump and low-pressure line setup leading to an 8-mm inside diameter pipe. Results from the laboratory were validated in the yard test to see parameters affecting the bridging. Finally, a well-specific robust workflow was constructed for diversion pill design. Modeling done on a high-resolution fracture hydrodynamics and in-situ kinetics model showed that width development in different scenarios varied from 1.5 to 3.0 mm. Laboratory testing was performed in 0.31- to 063-inch width rectangular slots to normalize the flow rate/area of the cross section, and the plug experienced pressure up to 1,200 psi for several hours at temperatures from 115 to 205°F. No extrusion was observed during the test, which is a valid indicator of plug stability. Sensitivity to flow conditions and carrier fluid properties were estimated. The diversion slurry was mixed in a 0.5 wt% solution of guar gum and displaced at pump rates 100 to 999 ml/min. A yard test was designed to see the bridging of the pill at various concentrations of 75 to 300 lbm/1,000 gal and rates of 0.5 to 3 gal/min. All the laboratory- and yard-scale experimental findings were combined with field case studies to understand fracture bridging for dynamic diversion applications. A workflow using modeling and advanced volumetrics design was devised to enhance the diversion success in field applications. This led to formulating a parametric design measure β, which showed direct correlation and effectiveness on the diversion process. This study gives a 360° solution-based understanding of diversion physics. The proposed combination of mechanical and chemical diversion is a cost-effective method for multistage fracturing. Current comprehensive research involving digitized cores and advanced modeling has significant potential to make this a reliable method to develop tight carbonate formations around the globe.

Purification of Crude Sodium Di-Uranate from Tummalapalle Source, India to Nuclear Grade Ammonium Di-Uranate Using Sulphamic Acid Dissolution Route

Crude Sodium Di-Uranate (SDU) of Tummalapalle mine India, contains 2-3% (w/w) of silica besides 5-7% (w/w) of organic matter including polyacrylamides and humic masses with 2-5% Zirconium (Zr) (w/w) as major impurities, hence the direct conversion of SDU, to Nuclear Grade (NG) Ammonium Di-Uranate Cake (ADUC) for fuel fabrication via HNO3-Tributyl Phosphate (TBP) extraction route is onerous due to silica gel creation, third phase inception enounces presence of excess Zr and micro-emulsion formation confirms organic matter introduces difficulties in filtration, recovery and purification stages. Various analytical techniques such as X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) as well as Inductively Coupled Optical Emission Spectrometer (ICP-OES) has been utilized to characterize raw material (SDU), intermediate products (gel and residues) as well as final product (NG-ADUC). In this research; an innovative, novel route for dissolution of SDU employing sulphamic acid (25% w/v) to remove silica, organic matter, and Zr followed by the conventional route to NG-ADU; eliminates the three major process difficulties viz., (i) gelation, (ii) third phase formation and (iii) microemulsion formation. In addition, sulphamic acid extracted Uranium (U)-bearing stream ultimately articulates 99.5% overall U recovery and enunciates nuclear grade U with desirable morphological characteristics.

Towards Bioleaching of a Vanadium Containing Magnetite for Metal Recovery

Vanadium – a transition metal – is found in the ferrous-ferric mineral, magnetite. Vanadium has many industrial applications, such as in the production of high-strength low-alloy steels, and its increasing global industrial consumption requires new primary sources. Bioleaching is a biotechnological process for microbially catalyzed dissolution of minerals and wastes for metal recovery such as biogenic organic acid dissolution of bauxite residues. In this study, 16S rRNA gene amplicon sequencing was used to identify microorganisms in Nordic mining environments influenced by vanadium containing sources. These data identified gene sequences that aligned to the Gluconobacter genus that produce gluconic acid. Several strategies for magnetite dissolution were tested including oxidative and reductive bioleaching by acidophilic microbes along with dissimilatory reduction by Shewanella spp. that did not yield significant metal release. In addition, abiotic dissolution of the magnetite was tested with gluconic and oxalic acids, and yielded 3.99 and 81.31% iron release as a proxy for vanadium release, respectively. As a proof of principle, leaching via gluconic acid production by Gluconobacter oxydans resulted in a maximum yield of 9.8% of the available iron and 3.3% of the vanadium. Addition of an increased concentration of glucose as electron donor for gluconic acid production alone, or in combination with calcium carbonate to buffer the pH, increased the rate of iron dissolution and final vanadium recoveries. These data suggest a strategy of biogenic organic acid mediated vanadium recovery from magnetite and point the way to testing additional microbial species to optimize the recovery.

Acid Dissolution of Neodymium Magnet Nd-Fe-B in Different Conditions

The separation of rare earth metals (REM) from a neodymium magnet has been widely studied in the last year. We have shown that the waste of computer hard disk contains 25.41 % neodymium, 64.09 % iron, and &amp;lt;&amp;lt;1 % boron. To further isolate rare-earth metals, the magnet was acidically dissolved in open and closed systems. In both methods of dissolution was used concentrated nitric acid. The difference between these methods are the conditions of dissolution of magnet. The magnet was dissolved in a microwave sample preparation system at different temperatures and pressures in a closed system. In the open system, the acid dissolution of the magnet conducted at room temperature. 0.2 g of the neodymium magnet sample was taken under two conditions, and the dissolution process in the closed system lasted 1 hour, and in the open system-30-40 minutes. The open system is a non-laborious, simple and cheap method of dissolving the magnet by comparing both systems. Therefore, an open sample preparation system is used for further work. To remove the iron in the magnet, oxalic acid was used and precipitated as oxalates under both conditions. According to the result of the ICP-MS method, it is shown that the neodymium and iron contents in the precipitate are 24.66 % and 0.06 %, respectively. This shows that the iron has almost completely passed to the filtrate. Thus, it is possible to remove the iron from the sample.