METHOD OF PRODUCING REDUCED GRAPHENE OXIDE FROM GRAPHITE KISH Russian patent published in 2021 - IPC C01B32/198 C09K5/10 B82Y40/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to recycling metallurgy wastes and can be used in production of ferrous and non-ferrous metals and alloys, production of metal composites, coatings and cooling agents. First, Kish-graphite is obtained and subjected to pretreatment, involving the following steps: screening with size separation and separating the fraction with particle size of 50–300 mcm; flotation of said Kish-graphite fraction; acid leaching at weight ratio of acid to Kish-graphite from 0.25 to 1.0; optional flushing and drying. Preliminarily treated Kish-graphite is mixed with acid and, optionally, sodium nitrate. Obtained mixture is held at temperature below 5 °C, adding an oxidiser and a component for terminating the oxidation reaction after achieving a given degree of oxidation. Obtained graphene (OG) oxide can be separated from the mixture by centrifugation, decantation or filtration, washed, dried and subjected to peeling by thermal or ultrasound. Then, exhaust gas is reduced to reduced graphene oxide (FOG). At leaching and oxidation stages there used is hydrochloric, phosphoric, sulphuric, nitric acid or their mixture. Oxidising agent is selected from potassium permanganate, H₂O₂, O₃, H₂S₂O₈, H₂SO₅, KNO₃, NaClO or mixtures thereof. Component used to terminate the oxidation reaction is selected from an acid, non-ionised or deionised water, H₂O₂ or mixtures thereof. Reducing agent is selected from ascorbic acid, urea or hydrazine hydrate.

EFFECT: method is simple, environmentally friendly, provides high-quality FOG from Kish-graphite, which is a waste of metallurgy.

22 cl, 1 tbl, 2 dwg