Sustainable recycling of iron concentrate obtained from the processing of iron-silicate uranium ore

Abstract

In the processing of iron silicate ore by blast-furnace smelting for uranium extraction, the problem of safe reuse of iron concentrate arises. That concentrate contains up to 65% of iron and therefore can be used as raw material for ferrous metallurgy. This provides significant resource savings compared to other industrial uranium ore processing technologies. However, the increased content of radioactive elements (U, Ra, Po) in this concentrate requires the development of methods for separating these elements before smelting. In this regard, we studied the distribution of radioactive elements (U, 228Ra, 210Po, and 210Pb) in ordinary ore of the Pershotravneve deposit (Ukraine) and other products (agglomerates, slag, dust, iron concentrate). Data on nitric acid leaching of ore under various conditions showed a possibility of reducing the radioactivity of slag for up to 84% calculated for 210Po and 210Pb. Results indicate a significant release of 210Po and 210Pb into the gaseous phase during agglomeration, which requires the implementation of an additional off-gases cleaning system. Nevertheless, the results show that mixing the iron concentrate with ordinary ore (in an amount of ≤3 wt%) leads to an insignificant increase in the overall activity during agglomeration (no more than 4–10% for 210Po and 210Pb altogether). Thus, such slags can be safely used as a building material.