ScandiVanadium presents regular updates on the progress of their Skåne project to investors. In their last update, which was published July 19, the company reports on the analysis of samples in collaboration with RISE (the Research Institutes of Sweden) and the University of Copenhagen. I thought it would be interesting to have a closer look at the information contained in this update and to compare it with what we already know about the Alum shale and its geochemistry since several decades.
ScandiVanadium‘s interest is in Vanadium, which is known to occur in very high amounts in the upper part of the Alum shale, in the so-called Dictyonema formation. The company’s idea is to open vanadium mines in eastern Skåne. The Alum shale is known for its high content of uranium and other toxic elements, which easily leak into soil and groundwater when the shale is subject to weathering. The uranium content is highest in the middle part of the Alum shale and decreases gradually upwards. However, even in the upper part of the Alum shale (sort skifer), which is the vanadium-rich Dictyonema formation (D1-D3), uranium is still present with around 40-80 ppm, as seen in the Figure published by Buchardt et al. 1997 and shown below.
Figure 17 from Buchardt, B., Nielsen, A. T. og Schovsbo, N. H.: Alun Skiferen i Skandinavien.
Geologisk Tidsskrift, 3, pp. 1-30, København, 1997-09-05.
The article by Schovsbo et al. (2002) presents how the uranium content in the Alum shale varies in time and space and compares analytical results on several drill cores from Skåne, Öland, Östergötland, Västergötland and Närke. The analysis of the uranium content in the Gislövshammar-2 core (which can be a representative for Skåne) refers to the figure and analyses presented in Buchardt et al. 1997, meaning that the values presented by Schovsbo et al. (2002) for Gislövshammar-2 are the exactly same values as shown in the figure above. What the comparison made by Schovsbo et al. shows is that the uranium content in the Dictyonema formation is lower than at the other sites, but it is still high!
Figure 5 from Schovsbo, N.H., 2002: Uranium enrichment shorewards in black shales:
A case study from the Scandinavian Alum Shale. GFF Vol. 124 (Pt. 2,
June), pp. 107–115. Stockholm. ISSN 1103-5897. See this article for further references to the various cores.
ScandiVanadium has taken samples in the outcrop at Flagabro (I wrote about Flagabro in one of my earlier blogs) and also got access to samples from the Fågeltofta-2 drill core, which is stored at the University of Copenhagen. Five samples from the Dictyonema formation from each locality were analysed by RISE using the μXRF fluorescence equipment M4 Tornado (Bruker).
One of the results of these analyses is that samples from weathered (Flagabro) and non-weathered Alum shale (Fågeltofta-2 drill core) show little differences, which means, according to ScandiVanadium “that there should be limited difference between the processing of weathered ore and fresh ore“. A further result of these analyses is “that the vanadium is distributed evenly throughout the clay matrix of the Dictyonema Seam. This indicates that there should be a very low nugget effect in Vanadium grade distribution which would allow broad spacing in exploration drilling“. In other words: weathered Alum shale seems to behave similar as non weathered shale and vanadium occurs in high amounts in both weathered and non-weathered alum shale. And – less drill cores would be needed to circle in the vanadium-rich part of the Alum shale.
None of this is great news and has been known for a long time, at least since the Andrarum (described by Westergård in 1944) and Flagabro drill cores were obtained (see Tjernvik 1958, 1960) and vanadium was mined during a short time at Flagabro as mentioned in an excursion guide from 1982 by Jan Bergström. For those of you who want to read the respective articles, here are the references:
Westergård, A. H. (1944): Borrningar genom Skånes alunskiffer, 1941-1942. SGU C
459, 45 pp.
Torsten E. Tjernvik (1958) The Tremadocian Beds at Flagabro in South-Eastern Scania (Sweden), Geologiska Föreningen i Stockholm Förhandlingar, 80:3, 259-276, DOI: 10.1080/11035895809454886.
Torsten E. Tjernvik (1960) The Lower Didymograptus Shales of the Flagabro Drilling Core, Geologiska Föreningen i Stockholm Förhandlingar, 82:2, 203-217, DOI: 10.1080/11035896009449193
What really caught my attention, however, was another statement by ScandiVanadium: “The occurrence of uranium was below detection limit for the XRF scan in all instances, confirming that uranium is only present in very low concentration in the Dictyonema Formation.” This is an interesting statement and merits some attention. As shown in the two figures above: the Dictyonema formation of the Alum shale has U contents of 40-80 ppm. But according to ScandiVanadium the U content was below detection limit. I did a bit of research regarding this and also contacted people at RISE to learn a bit more about the detection limit of their instruments. It is actually not so easy to detect U by XRF scanning unless the element is specifically targeted. Maybe ScandiVanadium should answer the following questions to support their statement: Was the measurement focus on U or not? What is the detection limit of U for the respective XRF instrument? How representative were the analysed samples in respect to U content? What other elements did the XRF analyses reveal?
The detection limit for U with most XRF scanning instruments is generally above 100 ppm, which means that lower U contents of 40-80 ppm are not easily captured. But it does certainly not mean that the analysed samples do not contain considerable amounts of U.
I have come to realise that ScandiVanadium wants to downplay the amount of U contained in the Dictyonema shale, because U is not a nice element to deal with. It would also be interesting to get detailed analyses of all the other (toxic and less-toxic) elements that should have appeared in the XRF scan. But these are not mentioned at all in the latest ASX update. Downplaying the U content in the shale (or not mentioning all the other toxic elements which are present in the Alum shale) really fits poorly with the picture of a green vanadium mine or sustainable mining, as ScandiVanadium‘s vision is continuously presented to various stake holders and politicians (only recently in the Magazine Filter).
If ScandiVanadium‘s CEO’s vision of sustainable mining, of contributing to saving the Planet and of helping the transition from fossil to green technologies really would hold true, then the company should focus on all the enormous mining waste deposits that contain tonnes of vanadium instead of opening new mines that will contaminate soils and groundwater for generations to come. A focus on old mining waste would really be something new and should be the first target for extracting vanadium and other innovative metals and minerals.
Promising the moon (lova guld och gröna skogar) to people in Skåne and Österlen and talking about how concerned ScandiVanadium‘s CEO is in respect to the environment is nothing else than fake news I am afraid.
Barbara Wohlfarth 