There are several methods in use for heavy liquid separations in the laboratory. A generic version is shown below.
Deslime sample. (Remove the very fine particles)
Screen over size material.
Dry sample. Split Sample.
Weigh sample to be separated.
Use only glass or plastic equipment and tools while working with LMT.
Adjust the density of the LMT by adding de ionized water or evaporating excess water (see below - Recycling LMT).
Add LMT at the desired density to a clean separatory funnel.
Place sample in separatory funnel and stir or shake to ensure the sample is wetted.
Allow the sample to separate(time will vary depending on the particle sizes and densities).
Drain the sink fraction from the separatory funnel.
Filter and rinse the sink fraction(using de ionized water), a Buckner funnel connected to a vacuum pump is ideal for this. Two to three wettings of the sample is usually sufficient.
Dry and weigh the sink fraction.
Drain, filter, rinse, dry and weigh the float fraction.
Place the filtered dilute LMT solution into a coverable glass container on a magnetically stirred hot plate. Do not cover the container while evaporating.
Heat while stirring to evaporate the excess liquid solution. It is ok heat the hot plate to 200 degrees C as long as the LMT is not dried out completely at above 100 degrees C as the LMT will be damaged.
Tip: Place a child’s glass marble in the solution - the marble will float when the LMT is near density. Depending on the marble, this is usually at about 2.7 Specific Gravity.
Evaporate the LMT until the solution is at the desired density.
Tip: If a 2.9 mg/l density or higher is desired, heat and stir the LMT until a film forms on the top of the solution. Turn off the heat, cover, leave the stirrer on and allow the sample to cool until the film dissipates.
Store LMT in a tightly sealed glass or plastic container.
Please contact us to discuss your specific application.