hydrochloric acid leaching: Topics by Science.gov
The leaching process uses three acid leaching steps with 0.1 M H2SO4 at 75degrees C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5 amperes (A) for 75 min. Ten counter-current remediation cycles were completed achieving > or = 94% copper extraction from the wood ...
Graphite purification methods and their advantages and …
In the process, the desiliconized product is leached with acid, so that the metal oxides in it are converted into soluble metal compounds, while impurities such as carbonates in graphite and acid-soluble compounds formed during the alkali leaching process react with acid and enter the liquid phase, and then separated from graphite by filtration ...
Purification of spent graphite and surface modification with …
Schematic diagram of pre-oxidation and acid leaching process for spent graphite. The AG and PG were obtained from the first and second leaching process, respectively. The levels of metal impurities in SG, AG, and PG were detected, and the results are presented in Table 1. It turns out that after the first leaching treatment, the content of ...
The Review of Existing Strategies of End-of-Life …
The leaching process is the most widely used treatment to liberate and purify the spent graphite anode. This hydrometallurgical strategy allows one to remove the impurities from the recovered graphite, and moreover, this …
How to Purify Graphite Ore?
In addition, there is also the disadvantage of graphite loss. 4. Acid Leaching. Acid leaching can use to purify graphite ore by sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, and other methods. Sulfuric acid and hydrochloric acid are more suitable for leaching, with strong leaching ability.
Separation Science and Technology Preparation of high-purity graphite
Alkali roasting pre-treatment and acid leaching process was used to prepare high-purity graphite from a fine microcrystalline graphite concentrate. The results showed that the alkali roasting pre-treatment and acid leaching process could enhance the fixed carbon of microcrystalline graphite to a higher level.
Purification effect of the methods used for the preparation …
Acid leaching, alkali roasting, chlorination roasting methods can be used to further upgrade the carbon content of graphite. However, the flotation, acid leaching, alkali roasting, chlorination roasting methods are less effective for microcrystalline graphite due to the dense, fine texture of microcrystalline graphite [13], [14]. When compared ...
Environmental Impacts of Graphite Recycling from …
Laboratory-scale recycling is scaled up into pilot-scale processes able to treat 100 kg of spent graphite. With values ranging from 0.53 to 9.76 kg·CO 2 equiv. per 1 kg of graphite, energy consumption and waste acid …
Purification of spent graphite and surface modification with …
In summary, the spent graphite underwent purification to yield industrial-grade graphite, accomplished through a tandem process of pre-oxidation coupled with acid leaching. Subsequently, the surface-modified graphite was synthesized utilizing a surface carbon-coating method which employed phenol–formaldehyde resin or coal tar pitch as ...
Zenyatta Announces a Simplified Graphite Purification Process …
The first phase program investigated a process based on high-pressure caustic leaching of graphite concentrate followed by acid leaching (Zenyatta Pressure Leach or ZPL). At this stage, our objective was to determine the efficacy of the process in removing the bulk of impurities and not to produce any specific purity of product.
Sci-Hub | Preparation of high-purity graphite from a fine
Wang, H., Feng, Q., Tang, X., & Liu, K. (2016). Preparation of high-purity graphite from a fine microcrystalline graphite concentrate: Effect of alkali roasting pre ...
Sulfuric Acid Leaching Process for Producing High Purity Graphite …
Based on the characteristics of roasted graphite concentrate from Bao Ha, Lao Cai district, the present research a technology to increase the purity of the graphite carbon from 92.6% to 98%. Study was conducted on leaching agents, concentration of sulfuric acid, temperature, time, liquid/solid ratio affecting the process.
Graphite Recycling from End‐of‐Life Lithium‐Ion …
Graphite (Gr) is the most common form of naturally occurring polymorphs of crystalline carbon, which typically occur as black crystal flakes and masses. ... recycled Gr via a hybrid process: sulfuric acid leaching combined …
Harnessing Regenerated Graphite from Spent Lithium‐Ion …
To treat spent graphite, leaching agents such as HCl, H 2 SO 4, citric acid, HNO 3, and H 3 BO 3 are used to remove impurities, followed by low-temperature calcination to rebuild the graphite structure. 8-15 Using the sulfate roasting method, some impurities in spent graphite were removed by transformed into their corresponding sulfate. 16 Gao ...
Graphite Ore Processing: Optimal Processes and Equipment
If high-purity graphite is required, further purification is required. The purification process includes a high-temperature method, thermal refining, hydrofluoric acid leaching, mixed acid leaching, etc. Among them, the high-temperature method is the most favored, which can purify graphite to more than 97-99%. Conclusion Graphite is on the cusp ...
Green & efficient regeneration of graphite anode from spent …
In this paper, we report a direct regeneration process for spent graphite anode. Using asphalt as the coated carbon source and spent graphite as the core, the asphalt …
Graphite regenerating from retired (LFP) lithium-ion battery: …
In order to remove metal impurities from spent graphite, hydrometallurgical process [[18], [19], [20]] was proposed to purify anode graphite.For example, Guo [18], Chang [19] and Yang [20] et al. adopted hydrochloric acid, H 2 SO 4 and citric acid as leaching agents, respectively, and then a pure graphite could be obtained.This method does not involve the …
AU633608B2
In the preferred two-stage HCl/NaOH leach process developed for upgrading graphite, SiO0 and Al 2 03 levels in the caustic solution increase due to the dissolution of clays in the ore. ... A method as claimed in any one of claims 1 to 3 in which the acid leaching step is carried out using 7.5% v/v of mineral acid to form a slurry of the ore and ...
Purification mechanism of microcrystalline graphite and …
Low impurity content is crucial for graphite applications and microcrystalline graphite is an important candidate material. In this study, natural microcrystalline graphite, with a fixed carbon content of 76.65%, was purified by an alkaline autoclave-acid leaching method. The effects of the mole ratio of NaOH to Si and Al in graphite, the liquid–solid ratio of NaOH …
Experimental Investigation on the Purification of Natural …
Material Characterization. X-ray fluorescence (XRF) analysis was carried out on raw materials and graphite samples at different stages of the purification process, namely, alkali melting and water washing, alkali melting, acid leaching followed by water washing, and the incorporation of sodium metaborate (4% of graphite mass) and potassium pyrosulfate (4% of …
Critical strategies for recycling process of graphite from …
Then, the copper was easily oxidized to copper oxide at 500 °C for 1 h under an air atmosphere. Subsequently, graphite and copper were separated using a simple acid leaching process. Graphite separated by this method met all of the technical indexes of regenerated anode materials and even exceed those of midrange graphite.
Development of vein graphite by optimizing the NaOH
In our previous studies, the optimum HCl concentration for acid leaching of raw vein graphite had been determined as 5 vol. % [6, 7, 32]. By utilizing that finding, the HCl acid leaching process performed under the present study resulted 99.2% of purity with 68.0% of impurity removal efficiency.
Re-utilization of waste graphite anode materials from spent …
The regeneration process of graphite in Fig. 1 outlines the synthesis schematic of LGG from purification to structural modification, which mainly involves acid leaching and high-temperature treatment. Firstly, the scrapped graphite was pretreated with the sulfuric acid solution, removing the residue metallic impurities and water-soluble substances.
Harnessing Regenerated Graphite from Spent …
In this work, a facile hydrometallurgical approach combined with heat treatment has been adopted to recycle spent graphite from retired lithium-ion battery cells. Graphite regenerated with 18 M H 2 SO 4 leaching leads to a …
Full article: Elemental Concentrations of Natural Graphite …
Preparation of high-purity graphite from a fine microcrystalline graphite concentrate: effect of alkali roasting pre-treatment and acid leaching process. Separation Science and Technology . 51 ( 14 ):2465–72. doi: 10.1080/01496395.2016.1206933.
A Complete Guide to Graphite Purification Process
Chemical Purification Systems for Graphite: Alkali roasting systems High temperatures and alkalies are utilized to remove non-carbonaceous impurities from the graphite. Acid leaching unit: Involves using acids in graphite purification process to extract out metal impurities and retain pure graphite. Hydrofluoric Acid-Based Purification
Preparation of high-purity graphite from a fine …
Graphite is one of four forms of crystalline carbon; the others are carbon nanotube, diamond, and fullerene.[1] ... Alkali roasting pre-treatment and acid leaching process was used to prepare high-purity graphite from a fine microcrystalline graphite concentrate. The results showed that the alkali roasting pre-treatment and acid leaching ...
Graphite Recycling from End‐of‐Life Lithium‐Ion …
In another research study, Liu and coworkers recycled Gr via a hybrid process: sulfuric acid leaching combined with thermal treatment at 800 °C, and utilized the R-Gr in anodes for SIBs application. The resulting anodes …
The Review of Existing Strategies of End-of-Life Graphite …
Later, the same research team investigated the impact of heat treatment temperature (heat treatment was conducted after the sulfuric acid leaching process) on the structural and morphological characteristics of the obtained graphite and, moreover, on its electrochemical behavior . The analysis of the obtained material demonstrated that even at ...
Purification and impurity evolution of natural graphite by alkali acid
The natural flake graphite (GO) with an initial fixed carbon content of 6.23% is purified using flotation combined with alkali-melting acid leaching to obtain the high purity graphite (PG3) for ...