Metals, Vol. 14, Pages 416: Study of Preg-Robbing with Quicklime in Gold Cyanide Solutions Analyzed by Time-of-Flight Secondary Ion Mass Spectrometry

Metals, Vol. 14, Pages 416: Study of Preg-Robbing with Quicklime in Gold Cyanide Solutions Analyzed by Time-of-Flight Secondary Ion Mass Spectrometry

Metals doi: 10.3390/met14040416

Authors: Eber Manuel Garcia Rosales Jesús Emilio Camporredondo Saucedo Yuriy Kudriavtsev Grover Johnny Mamani Maron Fernando Rojas Venegas Laura Guadalupe Castruita Avila

Preg-robbing is a phenomenon in which minerals retain gold, especially due to the presence of species like carbonaceous matter and silicates in the mineral. This study demonstrates the impact of quicklime, used to adjust the pH of a gold cyanidation solution, on the retention of gold contained in pregnant cyanidation solutions and sorption mechanisms. The retention capacity of four quicklime solutions was evaluated using proportions of 200 g of lime in 800 mL of solution and 10 g of lime in 500 mL of solution. The concentrations of the gold cyanide solutions were 10, 15, and 25 ppm. The insoluble lime residue in the acetic acid solution was separated and analyzed by XRD, FTIR, elemental carbon, and Raman spectroscopy techniques. SEM and TOF-SIMS were used to analyze the lime samples after exposure to the gold cyanide solution. The results show that retention was attributable to quicklime due to the effects of its carbon and silicate content, although chemisorption and physisorption mechanisms may also be responsible.