Mechanical Agitation in the Carbon-In-Pulp Process

Authors:

John A. Shaw

Robert J. McDonough

This paper discusses the role of mechanical agitation in the Carbon-in-Pulp (CIP) process used for gold extraction, emphasizing the relationship between energy, shear, and flow in agitator design. It compares open impeller agitation and draft tube circulator systems, analyzing their efficiency, power requirements, and impact on carbon attrition. Overall, the study concludes that while draft tube circulators have higher capital costs, they offer significantly lower power consumption and improved operational stability when properly designed.

Key Learnings

• Mechanical agitation plays a critical role in the efficiency of the Carbon-in-Pulp (CIP) process for gold recovery.
• Draft tube circulator systems provide more controlled flow and better mixing uniformity compared to open impeller systems.
• Proper impeller and tank design can significantly reduce power consumption and improve energy efficiency.
• Excessive shear rates can lead to carbon attrition, which negatively impacts process performance.
• The relationship between energy input, shear, and flow must be optimized for effective solids suspension and slurry mixing.
• Laser velocimetry provides valuable insights into flow patterns and mixing dynamics in different agitator configurations.
• Although draft tube circulators have higher initial costs, they offer long-term operational benefits through reduced energy use and maintenance needs.
• Understanding flow-controlled systems is essential for improving process reliability and scaling up CIP operations efficiently.