Selective attachment processes in ancient gold ore beneficiation

Ancient reports and mining relicts indicate that in antiquity technologies of high empirical level were used to enrich finely dispersed gold. This review describes the scientific bases behind these beneficiation technologies and confirms their historical significance. All of these ancient processes operate on the principle of selectively attaching finely dispersed gold particles onto a solid collector material via hydrophobicity, chemisorptive bonding, or electrical surface charges. This work begins by presenting the physical and chemical fundamentals of these processes. New research provides scientific explanations for several ancient variants of gold ore beneficiation that are discussed in the second section, including the dry and wet attachment processes used in pharaonic Egypt, sheepskins utilized as gold collectors in the Caucasian region, hemp utilized as a gold collector in Celtic Bohemia, and the use of gorse for gold beneficiation in the Roman Empire. The highest performing antique gold beneficiation technique was the use of gorse as a superhydrophobic gold collector and can be regarded as a precursor to the modern flotation process. The ancient processes demonstrate interesting correlations with modern gold ore beneficiation.