ION EXCHANGE RESINS
Ion exchange resins and activated
carbon are well known
collection medias for precious metals.
There are several aspects one needs to know before using these
medias for collection. Personal experimentation is the key as
each ore can be changeling.
Below are a few of the finding from these tests with a variety of
A method used is the spoon test.
Using a high grade of stainless steel
spoon, one can do a quick test to determine if the resin used has
collected any interesting metals. Only after further testing can one
determine the exact content of elements collected. The visual
microscope viewing will only tell the observer if metallic' have been collected. It
is important to know the Ph of the solutions, as acidic solution may contaminate
the spoon with the metallurgy of the spoon.
Assumptions can be made when working with raw platinum group metals and pgm minerals. The PGM's in nature are rarely found as native free elemetal metal. The minerals of pgm's do not act like metal and therefore one should not assume to be treated like zero valance elements.
Ores containing pgm range from not soluble to very soluble. Under the right conditions DH2O can place the mineral pgm into solution. Remember 100g of finely divided ore, - 1,000mesh, is more subject to going into solution than grains of sand. The range of pH can also be a factor as how soluble the pgm minerals can be.
Above is a spoon with ion exchange beads that were placed into a solution containing PGM/Au.
Above is a close up of the loaded
resin. This test used DH2O with loaded beads and
brought to a boil. The DH20 desorbed the metals as the ion state was still very soluble to do
so. Once the H20 evaporated, the metals remain not only in the resin, but as a crust on the
surface of the spoon.
Metals in a very unstable are also
very volatile and flash as a vapor to be collected as a skin
on the surface of the edge of the spoon. There may be some extra action of vapor, cementation ,
and residue deposits. Additional testing using SS in vapor cloud also collected metal on the SS.
Metals collected with this process
from another test, shows, suspected Au, and PGMs. What
is derived from this image is the PGM's dissolved in the H20 first and Au remained as a residue
locked in the beads. The spoon test uses a three step process in the ignition method. One bring the
heat up slow to a boil for as long as possible. Once the liquid has evaporated, let cool. Next
apply heat slowly until white smoke is observed, let cool. Next apply the flame until black smoke can be seen and stops. Let cool. The white smoke is residual elements which will flash at lower temperatures.
The black smoke is plastic matrix of the beads. If this is not done in steps values can be blown off with
some of the precious metals. The final step is bring the flame under the spoon to red hot heat, using map gas to reach 1,150F do not melt the spoon. The residue in the above spoon has Au/PGM's in all
the remaining residue.
Closer viewing of the residue is
loaded with Au, Pt, Ir, Rh, Ru, Pd, no Os was detected.
The reside is not loaded as precious metal popery. Some soluble in AR and some not.
The content of Ir, Rh, Ru is high therefore soluble fusions must be made to place them
into solution. Now how to part the alloy's of Au/Pt/Pd/Ru/Rh/Ir?
The above image is from a batch of
resin use in the same solution after several selected
stages of adding resin beads. When ion's of all the pgm's and Au are present there is a
selective step process in collection. This step shows mostly Au.
Au? Once it was determined the resin was caring Au, the side of spoon is gray
metal, and beads are brown Sn was placed as a collector.
The temperature was bung up to red
heat and melted Sn will flatten and pick up
Au readily. The temperature is reduced and a bead of Sn will soon coated with Au.
Sn is very good metal collection element. The above is an example of using Sn + ore + heat + flux +
fusion + mold = alloy. 5,000pm Au. with xray diffraction. Xray only penetrates a few microns . The samples were 1/4 inch to 3/8 think. The top and bottom read close to the same. Many reading were above 10,000pm.
With that said, the assumption is, all layers are the same, however hot and cold spots are also assumed.
The total value may be as hi as
150,000pm. The interfering factors are the Sn also collected other base metals
and pgm's. Parting these metal is the objective.