THE ROLE OF PROTECTIVE ALKALINITY AND CA2+ IONS IN THE CYANIDATION OFREFRACTORY SILVER ORES

The effect of protective alkali on the extraction of silver from refra ctory ores, taken from the Kutahya-Gumuskoy region of Turkey, and the behaviour of dissolved Ca2+ ions during cyanidation were investigated. It was shown that high concentrations of protective alkali are benefi cial in the cyanidation of these ores, in contrast to gold cyanidation where they prohibit gold dissolution. Calcium ions are advantageous i n the cyanidation of sulphidic silver ores since they prevent the detr imental effects of ions which hinder silver dissolution and consume CN - ions. Using high concentrations of protective alkalis decreases the cyanide consumption.