Synergistic lubricating performance of h-BN/GF nanoparticles as oil additives for steel-steel contact

The major objective of this work is to investigate the synergistic lubricating performance of hexagonal boron nitride (h-BN) and graphite fluoride (GF) nanoparticles (NPs) as lubricant additive in white oil. The tribological tests were carried out on steel-steel contacts using reciprocating ball-on-disk tribometer. Compared with white oil, addition of 0.1 wt. % h-BN/GF reduced the friction coefficient, wear rate and wear depth by 41.1 %, 89.1 %, and 92.3 %, respectively. Furthermore, when the mass ratio of h-BN and GF is 1:1 and the content of h-BN/GF nanocomposites is 0.1 wt. % the white oil show the best lubrication and wear resistance performance. Finally, the synergistic lubrication mechanism was investigated, the unique microstructure of the h-BN/GF composite and weak interfacial interaction between h-BN and GF contributed to the formation of continuous and adhesive tribo-films at the interface.

Occurrence State of Carbon and Electrolyte in Anode Carbon Residue From Electrolytic Aluminum

Anode carbon residue is produced in the production of electrolytic aluminum. Its properties need to be studied for secondary utilization. In this paper, mineralogy of anode carbon residue from an electrolytic aluminum plant in Guizhou was studied. The anode residue chemical composition, structure, mineral composition, occurrence state of main elements, etc, was investigated. The results show that: Anode carbon residue is mainly composed of 14 minerals such as cryolite, cryolithionite, elpasolite and graphite. Among them, the opaque minerals are mainly graphite and the transparent minerals are mainly cryolite. Carbon in the form of independent mineral occurrence in graphite; fluoride in the form of independent mineral occurrence in cryolite, cryolithionite, elpasolite and fluorite; aluminum in the form of independent mineral occurrence in cryolite, cryolithionite, elpasolite, aluminium oxide and magnesium aluminate; sodium in the form of independent mineral occurrence in cryolite, cryolithionite, elpasolite. The mineralogical characteristics and occurrence state of carbon and electrolyte were studied, which provided a basis for the separation and recovery of carbon and electrolyte in anode carbon residue.

Preparation and Applications of Fluorinated Graphenes

The present review focuses on the numerous routes for the preparation of fluorinated graphene (FG) according to the starting materials. Two strategies are considered: (i) addition of fluorine atoms on graphenes of various nature and quality and (ii) exfoliation of graphite fluoride. Chemical bonding in fluorinated graphene, related properties and a selection of applications for lubrication, energy storage, and gas sensing will then be discussed.