2000

Hintikka, Väinö; Parvinen, Pekka; Sten, Pekka; Laukkanen, Jukka; Leppinen, Jaakko

The possibilities of using mineral processing techniques to remediate rifle range soils were evaluated.The studied soils originated from two Finnish rifle ranges, Viikinmäki and Utti, and were heavily contaminated by lead- and copper-containing bullets and their disintegrated fine-grained weathering products.Most of the lead and copper in the soil samples is in the form of coarser particles, which can be easily recovered mechanically by combining wet sieving with consecutive gravity concentration stages.In this process, 83-85% of the total lead and 91-99% of the total copper can be recovered into a ca. 90% pure bullet product.The fine soil fraction contains 14-17% of the total lead, mainly as fine-grained carbona-ceous weathering products of the bullets, and 1-3% of the total copper.Due to the higher solubility of the lead carbonates and the high surface area of these particles, they form a significant source of contamination for the environment.Complex-forming leaching was used to recover the lead and copper from the fine soil fractions with recoveries of 95-98%.By combining the mechanical and leaching processes, lead and copper recoveries higher than 99.4% can be reached.