Insights into Alkali-Acid Leaching of Sericite: Dissolution Behavior and Mechanism

Abstract

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 investigated. The dissolution of sericite was mainly affected by alkali leaching temperature, sodium hydroxide concentration, and alkali leaching time. According to the XRD, FTIR, and SEM-EDS analyses, the dissolution mechanism of sericite is a three-stage process: (1) sericite is dissolved in the form of soluble silicate and aluminate; (2) the dissolved silicate and aluminate then react with each other to form aluminosilicate; and (3) finally the aluminosilicate mainly composed of hydroxycancrinite and sodalite is almost completely dissolved in the hydrochloric acid solution.

Synthesis of a MnO2/Fe3O4/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

“…2 shows the FTIR spectra of purified diatomite, Fe 3 O 4 /diatomite and MnO 2 /Fe 3 O 4 /diatomite. The broad peaks at 3400 and 1630 cm −1 that are observed in all three samples are typically related to stretching vibrations of hydroxyl (–OH) groups on the surface of the samples [ 22 ]. The peaks at 1094, 804 and 467 cm −1 are attributed to asymmetric stretching, symmetric stretching and bending modes of Si–O–Si bonds in diatomite [ 23 – 25 ].…”

Dual Copper (II) Complex Supported on Diatomite as a Novel and Green Catalyst for the Synthesis of Dihydropyrano[3;2‐b]Chromenediones and Aminopyranopyrans

“…The broad peaks around 3600 and 1600 cm À 1 , which can be seen in all samples, are related to stretching vibrations of hydroxyl (À OH) groups on the surface of the diatomite and modified diatomite. [38] The peaks at 1038 and 794 cm À 1 are attributed to asymmetric and symmetric stretching modes of SiÀ OÀ Si bonds in diatomite. [39][40][41][42] The band at 470 cm À 1 was assigned to bending SiÀ OÀ Si (Figure 1A).…”

Improved parameterization of the weathering kinetics module in the PROFILE and ForSAFE models

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