Leaching behavior of a low grade gold ore: A performance comparison of column and tank leaching

Today, with the rise of gold prices, exploration activities in Turkey have increased. As a result of this increase, the number of gold mines opened has increased day by day, and gold production has gained a great speed. As a result of these, the start of the operation of low-grade gold mines has also come to the agenda. The operation of low-grade or high-grade gold mines is made possible by the application of many chemical processes. This study was conducted by taking samples from Balıköy area of Tavşanlı District of Kütahya. Firstly, samples were sent to MTA laboratories for mineralogical-petrographic analysis in order to determine mineralogy. According to the laboratory results, the particle size ranges of which gold is heavily present were determined as -1000+500, -500+300 and -212+106 µm. In order to study the behavior of low-grade gold reserves belonging to the region in leaching tests, 2 different laboratory tests were applied and these were compared. These tests were column and tank leaching tests and examinations were carried out for different particle sizes. Column tests were applied for -20 mm and -12.5 mm breaking particle size and tank leaching tests were applied for -0.075 mm. NaCN was used in the leaching tests and Ca(OH)₂ (slaked lime) was preferred as the pH regulator. As a result of tests performed in different particle sizes, consumption values for both chemicals were calculated and comparisons were made. As a result of this research, gold recovery rates for low-grade gold ore were calculated and the maximum gold yield was realized at a particle size of -0.075 mm. As a result of this research, leaching behavior in different tests for low-grade ore was examined and appropriate methods were proposed for the gold acquisition process to be applied. Keywords: Gold Ore, Column Leaching, Tank Leaching, NaCN, Ca(OH)₂, Recovery.