I am a researcher focused on the iron and steel industry, and your questions have caught my attention. Given their strategic nature, I am pleased to respond. First, let me congratulate you on your insightful inquiries.
*
Publications from Mining Technology and Mining Intelligence and News point to two significant sites: the Malmberget Iron Ore Mine in Sweden and the Los Colorados mine in Chile. These findings are further supported by the article with DOI: https://doi.org/10.1007/s00126-019-00861-z. Personally, I believe that countries within the Pacific Alliance hold potential in this area.
*
While I do not have specific information about how much ore remains at these two sites, I suspect that areas with historical volcanic and magmatic activity could host potential iron skarn deposits.
For the near future, this may be either a useful prediction or a futile one, but I feel regions such as Central Asia and Mongolia, the Andes in South America, Greenland, Canada, and Alaska might offer potential. Whether this assumption will be confirmed by geological studies or dismissed as baseless remains to be seen.
*
In addition to the two aforementioned mines, I would also like to highlight the Kiirunavaara Mine in Sweden. A review of these sites reveals a consistent pattern, as the mines operated by LKAB are prominent in this field. There may be more detailed information in the company’s annual reports.