Standard Test Solution 100mg/100ml Gold

[lazersteve]

It was through the use of these types of standard test solutions along with some research into testing methods that I developed this straight forward way to test for Rh in solution with stannous chloride:

Rhodium Stannous Test

Of course, I didn't invent the process, I simply laid the testing procedure out in an easy to understand process, tested my results against standard solutions, and then posted the consolidated data for everyone to use in their Rhodium refining efforts. There is nothing more valuable in refining than concise, accurate test methods, with easy to obtain chemicals (preferrably on hand already). As Harold has stated numerous times, proper testing is your 'eyes' into the solution.

Once again, great job!

Steve

 

[kadriver]

Steve:

I have not gotten to rhodium yet - but I know it is probably already in some of my solutions.

I can look back and see the progression - first is was silver.

Next was gold, and a silver cell. then a long pause.

Then the platinum bug hit (with palladium making its appearance in the silver cell).

Finally arriving at rhodium.

Thank you for giving the test process for the rhodium - it seems the logical next element that will be showing up in my shop - and that right soon.

kadriver

 

[k2CO]

I have already bought from another seller - I told him up front that I would know right away if he was selling me palladium and not platinum - the DMG test don't lie.

He responded favorably. He knew about the swapping of palladium, and calling it platinum.

He guaranteed the item and said I would be pleased. I got a good vibe and placed the order for 2 grains at $11.65 each.

kadriver

First posting for a fairly new member...don't cringe yet! I've been slowly researching, reading and preparing to begin some experimentation on recovery and refining...the intuition-building phase. I was just going over how to make up the standard solutions for gold, platinum and palladium per Hoke and trying to assess what I need to create them. One big hurdle seems to be getting a small amount (2-10 grains) of pure platinum and palladium...shot or foil.

ka...was your source from this link an ebay seller?...can you share your source? Any other advice or direction from other forum members would be much appreciated...

Thank you,

- Richard (k2CO)

 

[patnor1011]

I have already bought from another seller - I told him up front that I would know right away if he was selling me palladium and not platinum - the DMG test don't lie.

He responded favorably. He knew about the swapping of palladium, and calling it platinum.

He guaranteed the item and said I would be pleased. I got a good vibe and placed the order for 2 grains at $11.65 each.

kadriver

First posting for a fairly new member...don't cringe yet! I've been slowly researching, reading and preparing to begin some experimentation on recovery and refining...the intuition-building phase. I was just going over how to make up the standard solutions for gold, platinum and palladium per Hoke and trying to assess what I need to create them. One big hurdle seems to be getting a small amount (2-10 grains) of pure platinum and palladium...shot or foil.

ka...was your source from this link an ebay seller?...can you share your source? Any other advice or direction from other forum members would be much appreciated...

Thank you,

- Richard (k2CO)

Ask any jeweller. I got mine from jeweller in city 1/4 or 1/2 gram is more than what you need. Pd dissolve in AR without much of a problem but I had to heat Pt in AR to dissolve it faster. I got 3-5 pieces of hair thin like Pt wire, total length about 5cm - weight not really measurable but when I placed it in AR and heated it gave me strong reaction when tested with stannous. And wires did not even dissolve completely.

 

[Lobby]

Picture of my standard test solutions.

I salute you. You are setting excellent examples in your structured and orderly approaches to refining.
The response you're getting from the attempt to dissolve platinum is exactly as it should be. You'll notice the color will be much lighter than palladium in solution, and will be somewhat more orange than gold in solution at that level of concentration.

Harold

I like this post. And I like this thread.

 

[manneke_pis]

Hi ..

I am interested in Standard Solutions as well.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=13998

after some research ideally I think Gold Standard Solution colour should be like :

 

[rewalston]

I have an oddball question. I've seen/read the instructions for making gold standard solution. A certain weight in a precise amount of aqua regia. Considering that nitric acid is rather expensive and really difficult to get, can HCl/bleach be used to make the standard solution instead?

Rusty

 

[Geo]

I have an oddball question. I've seen/read the instructions for making gold standard solution. A certain weight in a precise amount of aqua regia. Considering that nitric acid is rather expensive and really difficult to get, can HCl/bleach be used to make the standard solution instead?

Rusty

short answer, yes. AuCl is AuCl however you slice it.

 

[rewalston]

Thank you Geo, that was what I was thinking but I thought I'd ask anyway. Now all I need to do is get to the point where I can make some. Still collecting...never ending battle

Rusty

 

[g_axelsson]

I'm slowly reading up on all posts that happened during my two year hiatus from the forum. I will read all the posts on the forum... eventually. :mrgreen:

I just thought this is such a good thread on testing solutions it deserved to be brought back to life now and then.

There were just one tiny thing I noticed...

My scale is accurate to .1 grams.

I put a small 10 ml beaker on the scale and tared the scale to zero.

Then, using a very thin stainless steel blade, I transfered tiny amounts of dried gold powder to the beaker until it flipped from 0.0 grams to 0.1 grams.

I know this is not very accurate, but for now it will have to do.

By doing it that way you may have as much as 50% error in concentration even if the scale had no error in measurement. Bear with me, I'll try to explain what I mean.

For a scale that measures digitally it could do it in two ways:
- Round to nearest scale point.
0.00-0.05 -> 0.0g
0.05-0.15 -> 0.1g
0.15-0.25 -> 0.2g
...

- Truncate the scale
0.0-0.1 -> 0.0g
0.1-0.2 -> 0.1g
0.2-0.3 -> 0.2g
...

If you round to the digital scale used then your scale have an error of 0.05g, if you truncate then the scale have an error of 0.1g, therefore most digital scales uses the rounding method.
So when you measured your gold you might have gotten only 0.05g.
I suggest you would measure it this way...
1. put two small beakers on your scale and tare.
2. in the first beaker add gold powder until the scale starts to flip between 0.0 and 0.1g
3. in the second beaker add gold powder until the scale flips between 0.1 and 0.2g
4. use the gold in the second beaker to make your testing solution

This will also reveal how your scale measures. If the gold in the beakers seems to be equal then it uses the truncating method, if it is twice as much in the second beaker then it uses the rounding method.

Göran

 

[jonn]

Kadriver,
I just want to compliment you on a job well done, I have been following some of your other posts and must say I am very impressed. It's nice to see everything is well explained and I still can't figure how you keep everything so clean
Great job, please keep it up. Thank you

 

[Gratilla]

My scale is accurate to .1 grams.

I put a small 10 ml beaker on the scale and tared the scale to zero.

Then, using a very thin stainless steel blade, I transfered tiny amounts of dried gold powder to the beaker until it flipped from 0.0 grams to 0.1 grams.

I know this is not very accurate, but for now it will have to do.

Or, or, or...

Weigh out 1gm (ie one gram) gold powder, dissolve in 1 liter AR, take out 100ml for standard solution and recover the gold in the rest. Voila.

 

[Geo]

1g in 1L is very diluted. 1g in 500ml may be better. you need the standard to be very clear. if you need a dilute standard, you can always dilute with water.

 

[Gratilla]

I simply multiplied all the initial quantities by ten - in order to minimize the percentage of error.

I'll be making my own set of standard bottles (1ppm to 10ppm) in a week or so and have been doing some thinking. <ouch!>

 

[kadriver]

The test solution is used primarily to determine the potency of my stannous chloride solution. If my stannous test solution is old or giving weird results, then I can go to a know sample of gold test solution and test the stannous.

When I make a new batch of stannous chloride, I test it immediately using my standard gold test solution, then note the darkness, color, and general appearence of the reaction.

I can then use that as a reference to see if my stannous chloride is getting weak or going to the bad.

The amount of gold in the solution is not all that critical (according to C.M. Hoke) as long as you use the same concentration each time.

The 100ml of test solution I have will probably last me for the rest of my life and it will be here long after I am gone.

Hope this helps!

kadriver

 

[kadriver]

I stand corrected (after reviewing the book).

Hoke pg 93 says, "if your only objective is to become acquainted with the various solutions, it is not necessary to use exact measurements. But later on, when trying to estimate precious metal in a solution, it will be EXTREMELY helpful to have standard solutions made up with a definite weight of metal in a definite volume of liquid."

This makes sense when using the test solutions as a comparator to try and determine the amount of metal dissolved in a solution.

I can't recall ever doing it with gold. but I have tried to determine concentration of dissolved Pd in a solution, using a standard Pd test solution as a comparison.

I do use the gold test solution to test my stannous chloride test solution regularly.

So... The scale used to weigh out the metal to be used in a standard test solution (if it will be used as a comparator to determine dissolved metal concentration) should be as accurate as possible, probably down to at least .01 grams (my opinion, of course).

kadriver

 

[kadriver]

Kadriver,
I just want to compliment you on a job well done, I have been following some of your other posts and must say I am very impressed. It's nice to see everything is well explained and I still can't figure how you keep everything so clean
Great job, please keep it up. Thank you

Thank you for your kind words. It is always good to read encouraging responses for others concerning ones work efforts.

Kadriver

 

[g_axelsson]

I agree with you fully, kadriver, for verification that your stannous is working there is no need to have any known concentration. Just keep it quite diluted so that you know it will detect weak concentrations, any stronger concentration will work too.
But for quantitative measurements then your reference needs to be of a known concentration. Any error in the reference solution will automatically add to any measurements you try to do.

I hadn't read that in Hoke... haven't read it straight through yet ... but to do that is my new years resolution. 8)

The absolute limit of the measurement isn't the important thing, 0.03g with 0.01g error has an uncertainty of 33% while 30g with 1g error is only 3.3% uncertain. To get a good solution with a cheap scale, take for example 10.0g gold (+/-0.05g uncertainty for a scale with 0.1g step), dissolve, add water to 100 ml which gives 0.1g/ml or 100g/liter, call it solution A. Save some as a reference if you want.
From solution A take 1 ml, add 9 ml and you have a 0.01g/ml or 10g/liter standard solution.
From solution A take 1 ml, add 99 ml and you have a 0.001g/ml or 1g/liter standard solution.
Any standard solution you don't want to keep, just pour it into your favorite precipitation beaker and turn it back to gold again. Your standard solutions that you just made have a known concentration within a few percent, even as low as below 1% error. Most errors will come from how good you can measure the liquid volumes.
Keep your solutions in closed bottles all the time as evaporation will make them more concentrated over time.

Göran

 

[MEANIE]

I think this needs to bumped to the top.
Seeing kadriver went to the trouble to share with us (new people) IMHO to learn the right way to start recovering and refining .
Thanks kadriver you inspire me this is what I was trying to do and I looked in all the testing threads and didn't find what I was looking for.


Todd aka MEANIE

ps Thanks AndyWilliams for linking me here.