Humboldt H-1499 REFLUX EXTRACTOR - Manual (Page 2)

Introduction
This Reflux Extractor is designed using hot solvent extraction, determines percentage
of bitumen in paving mixture. For H-1495 each cone has 500g capacity and for
replacement filter paper use H-1497 series. For H-1499 each cone has 1,000g capacity
and for replacement filter paper use H-1482 or H-1498 series. Components are available
as replacement parts.
Sample Preparation
1. If the mixture is not sufficiently soft to separate with a spatula or trowel, place
approximately 4,000g in a large flat pan and warm in the oven at 240°F (115.6°C)
only until it can be so handled. Separate the mixture using care not to fracture
the mineral particles. Mix and quarter the warm material to obtain a portion for
extraction weighing approximately 1,000g. For routine testing, smaller samples
maybe used when the maximum size aggregate therein is less than ¼" (6.4mm).
2. At the same time weigh a 500g portion into a metal still, Humboldt 1871,
conforming to section 2 (A) of the standard method of test for moisture or volatile
distillates in bituminous mixtures (AASHTO) Designation T-110 & ASTM D1461.
3. Dry, if necessary and weigh two sheets of filter paper. Fold each sheet separately on
its diameter and fold twice again, one fold being made over the other to make three
segments. Open to form a hollow 3-ply cone with a single 1-ply seam and place in
wire cones of extractor frames.
4. Weigh each frame with filter paper in cone to nearest 0.1g. Record these tare
weights identifying each frame by number (see Note below).
5. Place approximately 500g of the prepared sample for the H-1495 and 1,000g for
the H-1499 reflux extractors in each of the filter paper lined cones and weigh the
loaded frames to the nearest 0.1g (see Note below). Compact each of the portions
by tamping lightly with finger or spatula blade.
6. Assemble the load frames and place in jar. Carefully pour about 500ml of solvent
over sample in top frame. At no time should the solvent level contact the tip of the
cone in the lower frame. Four or five glass beads placed in jar will facilitate easy
boiling of solvent.
7. Place loaded jar on electric hot plate with ceramic pad between glass and the
heating element cover with condenser and circulate cold water by just cracking
water valve open and waiting for flow.
Caution: Opening the water valve fully will subject the condenser to excessive
pressure beyond the 4 psi limit at which units are 100% factory tested.
8. Adjust heater so that solvent boils gently and a steady flow of condensed solvent
drips into the top cone. Care must be taken to adjust heat so that each portion
of sample is covered with solvent and at the same time the filter cones do not
overflow.
9. Continue extraction until solvent running from tip of lower cone appears colorless
when viewed against a white background. Then shut off heat but not water through
condenser and allow standing until cool enough to handle.
10. Remove frames from jar, dry first in air and then to constant weight in an oven at
240°F (see Note below). If drying at 240°F causes the filter papers to become so
brittle they cannot be handled and brushed, they may be dried separately from the
aggregate and at a lower temperature.