Laserfiche WebLink
r <br /> NICKEL TAILINGS <br /> 270 <br /> &-CONTROL <br /> 260 x-PR2000 x <br /> 250 <br /> u 240 <br /> X <br /> X <br /> g 230 <br /> E 220 <br /> 0 210 <br /> U - <br /> Q 200 <br /> 190 <br /> x <br /> 180 <br /> 0 10 20 30 40 50 60 <br /> TIME in DAYS <br /> Figure 9. Acidity from Incubation of Nickel Tailings <br /> Batch incubation data by itself shows that significant inhibition <br /> of iron-oxidation and subsequent pyrite oxidation and acid formation <br /> were . witnessed only for copper ore tailings. The lack of a positive <br /> bacterial response for! nickel- leachates suggests that inorganic <br /> kinetics were governing the pyritic oxidation and the nickel tailings <br /> were not acidic enough for vigorous - bacterial activity. However, <br /> uranium tailing leachates exhibiting strong positive bacterial <br /> responses produced minimal levels of acid inhibition during interim <br /> incubation periods. - High baseline acidities for this material may <br /> generate potential acid hydrolysis of the bactericide solution- <br /> producing limited effects. <br /> FUTURE OF BACTERICIDES IN THE PREVENTION OF AMD <br /> With the rebound of mining and an increased concern to restore <br /> mined land to its original condition, bactericides may become standard <br /> practice in reclamation. Indeed, Ohio, Illinois and Indiana have cited <br /> ProMac Systems- in their reclamation specifications.;- Montana, West <br /> Virginia, California, Texas, and Pennsylvania are expected to follow <br /> suit. <br /> Microbial based technologies have allowed the extraction of metals <br /> from low grade ores, thereby increasing the volume of waste associated <br /> with these operations. T. ferrooxidans is the most widely studied <br /> leaching microorganism of economic-importance.. Bactericide technology <br /> may hold _the key to the disposal of such wastes. <br /> . '� rmrl t <br />