Effect of Particle Size and pH on Recovery of Gold with Bottle Roll Test Method at PT Citra Palu Minerals

Sari, Rayska Hayu Randana
Prayuditha, Margaretha

Journal of Metallurgical Engineering and Processing Technology
(August 2025)

Bottle Roll Test (BRT) is a leaching testing method on a laboratory scale used in this test. The sample tested was low grade gold ore (< 1 ppm Au) from Poboya, Palu, Central Sulawesi at PT Citra Palu Minerals. Leaching was carried out for 24 hours with samples taken at 2, 4, 6, 12, and 24 hours. The parameters tested were particle size (-125 +100 µm, -100 +75 µm, and -75 µm), and pH (10-11, 11-12, and 12-13). The parameters set are 48% solid percent, 300 ppm cyanide concentration, dissolved oxygen using free air, 50 RPM agitation speed, and 24 hours leaching residence time. The research results showed that the highest gold recovery was obtained in samples with particle size of -75 µm and a pH of 10-11. The highest gold recovery is 91,5%.