A step towards meeting battery raw material demand: the geology and exploration of graphite deposits, examples from northern Norway

Abstract

Abstract In northern Norway, we have identified more than 40 occurrences of graphite through airborne geophysical surveys and follow-up fieldwork. Out of these, 29 have been investigated in detail using ground-based geophysical methods. For 21 of these occurrences, in combination with surface sampling, it is possible to estimate approximately the grade and tonnage of graphite. The graphite deposits are concentrated in two areas: the island of Senja and the Lofoten–Vesterålen islands. The aggregated tonnage and average graphite grade are 8.1 Mt and 12.6% graphite, respectively. Data collected from 17 international deposits show similar averages of 30.7 Mt and 10.8% graphite. Thus, the Norwegian deposits show a similar span in tonnage and grade and are most likely typical for graphite deposits worldwide. Similarly, and common elsewhere, the Norwegian graphite deposits in a succession of high metamorphic grade supracrustal rocks, comprising meta-arenites, carbonates and garnet- and pyroxene-bearing gneisses of variable composition. In parts, this succession is migmatized. Two bench-scale ore-dressing trials show that the graphite can be upgraded to market quality. Our work demonstrates a successful approach for locating and evaluating graphite deposits by combining nearly all the methods used in economic geology investigations.