Procedure Title: Solvent Cleaning
Instrumentation: Soxhlet Extractor apparatus
Theory of Operation:
Solvent cleaning is a process of removing the effect of the mud additives and drilling fluids from the rock samples by repeatedly flushing the sample with an appropriate solvent such as Dichloromethane and methanol (DCM/MeOH; continuous extraction) until the sample becomes free of all contamination.
Remove any obvious contaminants from the sample.
Clean and crush the sample to pass through a 180-Mesh sieve.
Weigh the sample.
Each sample is placed in a clean filter paper and tightly folded. Up to 40 samples can be fitted in a 2000 cc Soxhlet or 20 samples in a 500 cc Soxhlet.
Clean solvent (mix of Dichloromethane and methanol) is added to the apparatus; the analyst assembles the apparatus and ensures that the cold water is circulating through the condenser.
The duration of the solvent cleaning depends on the degree of sample contamination, while repeatedly changing the solvent as it becomes saturated with extracted contaminant.
The samples will be considered clean when the circulated solvent is totally clear.
The samples are removed from the Soxhlet and placed in an oven at low temperature to evaporate the solvent.