Comparison of gold extraction yields by cyanide treatment vs. bioleaching procedure

<p>Samples from the tailings of the Picacho mine in California were leached using NaCN and native bacteria, <em>Alcaligenes faecalis,</em> in column experiments to compare the gold recovery yields in the effluents. Four columns were treated with a different liquid: water, bacteria, NaCN and a mixture of cyanide and bacteria. After they were leached the effluents were analyzed to determine gold yields. During experiment I the total Au recovered in the effluent in the column treated with bacteria was only 10.09% less than those treated with cyanide (C2) and 81.7% more than the control. In experiment II, Au values measured were below detection limits. In experiment III Au recovered in the effluents for the Bacteria Column was 18.51% less than the Cyanide (C2) column and 34.27% more than the control.. Mass balance calculations for experiment I show that the column treated with bacteria has a higher percentage recovery yield of the Au recovered in both the effluent (18%) and in the two columns treated with cyanide (13% and 15%, respectively). In experiment III, mass balance calculations show that the percentage of Au recovered in the effluents of the columns treated with the bacteria was 15% and the other two columns trreated with cyanide had 25% of Au from the effluents. These findings indicates that the use of <em>A.faecalis</em> as an encouraging option for Au leaching of mine tailings which requires little supervision that translates in lower costs. The leaching treatment with bacteria produced favorable results that challenge cyanidation.</p>

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Earth and Atmospheric Sciences

Year dc:date.available

2019

Author dc:creator

• Pineda, Yilman Steven

Contributors dc:contributor

• Karin Block

• bioleaching
• Alcaligenes
• faecalis
• gold
• recovery
• mining
• Environmental Sciences
• Natural Resource Economics
• Other Environmental Sciences

Repository record dc:identifier

https://academicworks.cuny.edu/cc_etds_theses/770

OAI identifier oai:identifier

oai:academicworks.cuny.edu:cc_etds_theses-1835