Diluent
also known as carrier solvent · kerosene
The diluent is the bulk of the organic phase — typically a hydrotreated kerosene or a similar aliphatic cut. It does not take part in the extraction reaction, but it sets the organic's viscosity, density and interfacial tension, and therefore the droplet size, coalescence behaviour and phase disengagement time of the system. Its flash point and aromatic content are safety-relevant.
Why it matters in practice
Changing the diluent changes phase disengagement time even when the extractant and chemistry are unchanged, so a diluent substitution is never a purely administrative change. It is also the main driver of the organic phase's fire classification and of operator exposure.
Where this appears on this site
Equipment referenced in this entry
Related terms
Reference entry GL-DILUENT. Definitions on this page describe engineering practice in hydrometallurgical process design; they are not a substitute for test work on your own material.