Caractérisation De La Pratique Et Besoins De L’orpaillage Artisanal A Dabolava : Vers La Conception D’un Séparateur Gravimétrique Adapté

This study characterizes artisanal gold mining practices in Dabolava (Madagascar) to define the requirements for adapted mechanization. Despite an attractive gold price (350,000 Ar/g in 2024, ≈70€),), the activity, practiced by individuals aged 10 to 60, remains inefficient. Statistical analysis reveals a major disconnect between labor and output (R2 = 0.23), with a marginal yield of only 0.021 g/h. Particle size analysis using the Gates-Gaudin-Schumann (GGS) model proves that the resource consists primarily of fine gold. The application of Stokes' Law establishes a critical terminal settling velocity of 0.10 m/s, confirming that manual panning turbulences prevent the sedimentation of these micro-particles. These findings demonstrate the urgent need for a transition toward mechanical gravity separation. This study sets the technical specifications for a prototype capable of maintaining a controlled laminar flow, which is essential for optimizing fine gold recovery and sustainably improving the income of local micro-production units. « Caractérisation de la pratique et besoins de l’orpaillage artisanal à Dabolava : Vers la conception d’un séparateur gravimétrique adapté »