Precious Metals Recovery LLC RCRA Permit Application Dry Hills ...

9.0 METHOD PERFORMANCE
9.1 Ruggedness. Two ruggedness studies have been performed to determine
the effect of various perturbations on specific elements of the TCLP protocol.
Ruggedness testing determines the sensitivity of small procedural variations
which might be expected to occur during routine laboratory application.
9.1.1 Metals - The following conditions were used when leaching
a waste for metals analysis:
Varying Conditions
Liquid/Solid ratio 19:1 vs. 21:1
Extraction time 16 hours vs. 18 hours
Headspace 20% vs. 60%
Buffer #2 acidity 190 meq vs. 210 meq
Acid-washed filters yes vs. no
Filter type 0.7 µm glass fiber vs. 0.45 µm
vs. polycarbonate
Bottle type borosilicate vs. flint glass
Of the seven method variations examined, acidity of the extraction
fluid had the greatest impact on the results. Four of 13 metals from an
API separator sludge/electroplating waste (API/EW) mixture and two of
three metals from an ammonia lime still bottom waste were extracted at
higher levels by the more acidic buffer. Because of the sensitivity to pH
changes, the method requires that the extraction fluids be prepared so
that the final pH is within + 0.05 units as specified.
9.1.2 Volatile Organic Compounds - The following conditions were
used when leaching a waste for VOC analysis:
Varying Conditions
Liquid/Solid ratio 19:1 vs. 21:1
Headspace 0% vs. 5%
Buffer #1 acidity 60 meq vs. 80 meq
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Method of storing extract Syringe vs. Tedlar bag
Aliquotting yes vs. no
Pressure behind piston 0 psi vs. 20 psi
CD-ROM 1311- 22 Revision 0
July 1992