Purification process of natural graphite as anode for Li-ion …
Finally, the study suggests that introducing fluoride salts may be a promising method for deep impurity removal in the ultrasound-assisted hydrochloric acid leaching process of aphanitic graphite. Effective purification of graphite via low pulp density flotation-low temperature alkali roasting-acid leaching route: From laboratory-scale to …
Recycling of graphite anode from spent lithium‐ion …
Graphite has a layer structure and the original distance between graphite layers is 0.335 nm. 68 In the charging and discharging process, the interlayer spacing of graphite expands to accommodate Li +. 69 Previous researches indicated that the interlayer spacing of recovered GA is about 0.3703 nm, 70 which is ~10.5% higher than fresh GA. It is ...
Environmental Impacts of Graphite Recycling from Spent …
Graphite recycling/regeneration has been accomplished through diverse approaches, including hydrometallurgical methods based on acid–base leaching processes (for example by using acids HCl or H 2 SO 4) or a pyrometallurgical process where graphite is treated under temperatures above 1000 °C so that the residual metals, metal oxides, and ...
Determination of Elements in Acid Leaching of Graphite …
Keywords: graphite, nuclear material, INAA, acid leaching, element determination 1. Introduction Graphite which is a naturally occurring crystal carbon polymorphs is composed of a series of stacked parallel layer planes of the carbon structure. Graphite has been widely used in many application in various fields, such as metallurgy
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 …
Research on the process of carbon thermal reduction for
In the study of the acid-leaching liquid–solid ratio, the acid-leaching process was controlled at a stirring speed of 300 rpm and an acid concentration of 3.5 mol/l. Liquid–solid ratios in the range of 5–15 ml/g were selected for the study, and the metal ion leaching rates were obtained as shown in Fig. 5 g.
(PDF) Effect of acid leaching on upgrading the graphite …
The optimal leaching parameters were time reaction 120 minutes, temperature 180° C, solid-liquid ratio 1:5 and purity of acid 48%. The determination of the carbon content showed that the carbon ...
Development of vein graphite by optimizing the NaOH
However, when the acid-alkali-acid, H2SO4/H2O2-NaOH−HCl, chemical purification process was employed in this study, CC was significantly improved to 99.68 % (or 99.72 % after additional HF ...
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.
Effective purification of graphite via low pulp density …
Semantic Scholar extracted view of "Effective purification of graphite via low pulp density flotation-low temperature alkali roasting-acid leaching route: From laboratory-scale to pilot-scale" by Hochol Ri et al. ... ABSTRACT Purification of microcrystalline graphite concentrate with alkali-acid leaching process was studied in this paper. The ...
Effect of ultrasound power on HCl leaching kinetics of …
Wang, et al. increased the carbon content of aphanitic graphite from 90.20 % to 99.00 % by combining alkali roasting (1 h roasting time) and acid leaching process (2 h leching time). Kaya and Canbazoğlu [ 27 ] reported that the fixed carbon content of graphite can be increased by ∼ 60 % with 20 % HCl + 4 % HF and 4 h of leaching time.
Purification of Waste Graphite from Crucibles …
WG was purified using an alkaline-acid method, whose optimal process parameters were a solid alkali ratio of 3, calcination temperature of 600 °C, calcination time of 120 min, HCl concentration of …
Effect of roasting and acid leaching process on graphite …
A procedure based on acid extraction using a mixture of conc. sulfuric and nitric acids (8:1) to recover graphite attached to rock pieces of the vein contact zones of graphite mines, is developed ...
Development of vein graphite by optimizing the NaOH
Altogether, this novel combined alkali roasting and HCl acid leaching method have resulted in adequate purification and modification as well as promising …
[PDF] 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. The technological …
Recovery and Reuse of Anode Graphite from Spent Lithium …
With the rapid growth of retired lithium-ion batteries (LIBs), the recycling of electrode materials has become a hot topic in research. Considering the economic factors, the recovery of cathode electrodes has always been the focus of research. Until now, the recovery of anode electrode materials has gained much attention due to their large …
The dissolution behavior and mechanism of kaolinite in alkali-acid …
Compare the XRD patterns of graphite before and after chemical purification (shown in supplementary material), the silicate impurity mainly composed of kaolinite in microcrystalline graphite concentrate was removed completely by alkali-acid leaching process, which was the main reason for the improvement on purity of graphite.
Graphite Recycling from End‐of‐Life Lithium‐Ion Batteries: …
According to the recent advances regarding Gr recycling, three major regeneration processes of Gr are categorized, including i) washing Gr with different …
Minerals | Free Full-Text | Insights into Alkali-Acid Leaching …
Sericite is a typical silicate impurity in microcrystalline graphite ores, and its removal is important in the preparation of high-purity graphite preparations. Alkali-acid leaching is an effective method used to purify graphite and remove silicate minerals. In this study, the dissolution behavior and mechanism of sericite in alkali-acid leaching were …
A novel technique for microcrystalline graphite
The kinetic process analyses indicated that the aphanitic graphite acid leaching process for the ore fitted well with the unreacted shrinkage core model (diffusion reaction). The reaction's ...
Regeneration of graphite and manganese carbonate from …
For the mixed powder of lithium manganate and graphite, the acid leaching process was used to separate graphite and metal elements such as lithium and manganese. When the concentration of H 2 SO 4 is 0.5 mol/L and the concentration of H 2 O 2 is 6%, LiMn 2 O 4 is basically completely decomposed, ...
A promising method for recovery of graphite and cathode
For the acid leaching process, the aim is to convert the metals in the cathode active materials obtained from the above pretreatment process to ions in a …
(PDF) Purification of Indonesian Natural Graphite …
This paper focuses on the purification of the Indonesian natural graphite by using hydrometallurgy method with acid treatments. The characteristic of the purified graphite was studied for its...
Progress in separation, purification, and application of flake graphite …
When Liu Yuhai et al. [4] used alkali melting and acid leaching to purify fine flake graphite in a place in Heilongjiang Province, by discussing the appropriate process parameters, the fixed carbon content of graphite was increased from 95.89% to 99.94% by alkali melting roasting water leaching acid leaching process.
Regenerating spent graphite from scrapped lithium-ion …
2.2. Acid leaching and high-temperature treatment. Spent graphite was first treated via sulfuric acid solution. 100 g of spent graphite was weighed and added into 200 g/L sulfuric acid (H 2 SO 4) solution.The leaching conditions included a water bath temperature of 95 °C, a liquid-solid ratio (L/S) of 5:1, a reaction time of 4 h, and magnetic …
Preparation of high-purity and low-sulphur graphite from …
An alkali roasting process, which consists of roasting with caustic soda, water washing and sulphuric acid leaching, has been found to be an effective method for graphite purification even at low roasting temperature. With this process, a flotation fine concentrate containing 87–88% carbon could be purified to about 99.4% carbon when …
(PDF) Purification of Indonesian Natural …
The obtained graphite concentrates with an enriched carbon content above 90% after flotation was subjected to chemical treatment process including alkali roasting and acid leaching, which yielded ...
Recovery and regeneration of anode graphite …
The spent graphite, the commercial graphite and the regenerated graphite obtained by a conventional and commonly used acid leaching method were selected as control groups for comparison …
Hydrometallurgical recycling of EV lithium-ion
A reducing thermal treatment followed by acid leaching was studied by Yang et al. (2016) ... Li et al. (2016) studied this process using graphite from the anode, ... an easier leaching process could be attained, involving lower energy consumption, with no H 2 emissions and more facile conditions for a complete leaching. (6) ...
Preparation of high purity graphite by an alkaline roasting–leaching …
An alkaline roasting-leaching method was used to prepare high purity graphite from flake graphite from Hubei Jinchang instead of the commonly-used alkaline-acid method. The process parameters were ...