- Joined
- Jun 28, 2020
- Messages
- 38
Again, apologies if I'm asking too many questions in forum. If so, just respond or PM me. Let me know.
I'd like to determine if I have rhodium in PGM test samples from concentrates. How can this be done (other than sending off for assay)? Here's background.
I've been testing samples of placer panning concentrates. If samples seem adequately interesting, then I send them off for assay. The test process (to determine "interesting-ness") that seems to work the best for me given small sample sizes is to dissolve sample in AR, test with stannous chloride, and then validate stannous chloride test by cementing out values on copper. With this process, I can categorize (well enough) material in samples as gold, palladium, platinum , or other PGM. "Other PGM", as it turns out, is problematic as a category.
Here's the challenge. I have sample material that has low concentrations of gold and palladium. Maybe a little platinum. Not a huge surprise, since assays of local rocks gave similar results. The placer samples' relative concentrations of aforementioned minerals are greater than ore concentrations. However, not enough to get terribly excited about. ... well, unless samples happen to contain noticeable amounts of rhodium.
Rhodium is insanely rare, so do I actually have enough to be noticeable given my rudimentary testing rubric? Probably not. However, I have test material that might be rhodium based on process of elimination.
The mystery material doesn't dissolve is warm AR. It does dissolve (with difficulty) in boiling temperature AR. Once dissolved, this material can be cemented out of solution with copper. The material has metallic luster and is highly reflective. It appears in placer concentrates in combination with magnetite or some other ferromagnetic mineral. Finally, mystery material is lighter than gold but still heavy in pan, about same apparent density of lead.
Given above, it'd be quite useful if I could either rule out presence of rhodium or further verify that it might be present.
In the end, I could just send off samples for assay. However, experience with past assay results motivates me to test as much as I can before falling back on assaying. It saves a lot of money
I'd like to determine if I have rhodium in PGM test samples from concentrates. How can this be done (other than sending off for assay)? Here's background.
I've been testing samples of placer panning concentrates. If samples seem adequately interesting, then I send them off for assay. The test process (to determine "interesting-ness") that seems to work the best for me given small sample sizes is to dissolve sample in AR, test with stannous chloride, and then validate stannous chloride test by cementing out values on copper. With this process, I can categorize (well enough) material in samples as gold, palladium, platinum , or other PGM. "Other PGM", as it turns out, is problematic as a category.
Here's the challenge. I have sample material that has low concentrations of gold and palladium. Maybe a little platinum. Not a huge surprise, since assays of local rocks gave similar results. The placer samples' relative concentrations of aforementioned minerals are greater than ore concentrations. However, not enough to get terribly excited about. ... well, unless samples happen to contain noticeable amounts of rhodium.
Rhodium is insanely rare, so do I actually have enough to be noticeable given my rudimentary testing rubric? Probably not. However, I have test material that might be rhodium based on process of elimination.
The mystery material doesn't dissolve is warm AR. It does dissolve (with difficulty) in boiling temperature AR. Once dissolved, this material can be cemented out of solution with copper. The material has metallic luster and is highly reflective. It appears in placer concentrates in combination with magnetite or some other ferromagnetic mineral. Finally, mystery material is lighter than gold but still heavy in pan, about same apparent density of lead.
Given above, it'd be quite useful if I could either rule out presence of rhodium or further verify that it might be present.
In the end, I could just send off samples for assay. However, experience with past assay results motivates me to test as much as I can before falling back on assaying. It saves a lot of money
