Help with Assay results as it relates to fine gold recovery from earlier thread
Welcome guest, is this your first visit?
Member
Discoveries
 
Results 1 to 5 of 5
  1. #1
    us
    Nov 2009
    27
    2 times
    All Types Of Treasure Hunting

    Help with Assay results as it relates to fine gold recovery from earlier thread

    Hello:

    Can anyone help out with some calculations from an Assay, if would be greatly appreciated.

    As per a previous post re: fine gold recovery. Lots of good advice have just built classifier system to get all material under 1/8 of an inch with ability to go through 10 tons of material a day. End Result will be 3 tons of classified material from which we can expect 1000 pounds of black sand. We took a sample of the black sand which will be the final material run in a ball mill. So, from the results below can anyone extrapolate as to how much gold we can expect per 1000 pounds of black sand based on assay results? Or if anyone else has any ideas on how to make a determination if this is a worthwhile project to pursue that would be great too! This is new territory for me and all advice and ideas are encouraged and appreciated. Here are assay results,

    Summary:
    Sample preparation:
    ICP-OES analysis:
    • The calibration was done with a 5 ppm and 1 ppm mixed CMS-2 standard from Inorganic Ventures, Inc. These standards were dilutions from an original 10 ppm standard (Lot#D2-MEB324017).
    • Weight started with: 5.4757 gm black sands; Aqua Regia used: 37.1841 gm.
    • Sample (as received) was digested at 80⁰C for 1 hour.
    • 2 mL of sample digest, 0.14 mL internal standard solution (Y/Sc) were diluted to 14 mL with deionized water. Thus, the dilution is 7X, with this taken into account.
    • Where ever it is noted in the concentration as INTF, this means there was interference from other non-precious metals.
    • Where it is noted as ND, this means “not detected”
    • A different CMS-2 standard was tested at the end having the concentration of 7 ppm as a check.
    • Qualifying Statement: Given the fact there is obviously a lot of other metals in this sample, the best we can do here is to note where there is clearly interference from other elements (i.e. where there is a large difference in the signal at two different emission wavelengths). If the response is similar at both wavelengths we have a good chance that the signal is probably real, but there is still a possibility that there is equal interference at both wavelengths, which is rare.

    Results:
    1. Black Sand Sample
    a. Au (267.959 nm) = 7.54 ppm (0.000754 wt%)
    i. Calibration: R2=0.999996 (5 ppm, 1 ppm, thru 0)
    b. Au (242.795 nm) = 10.71 ppm (0.00107 wt%)
    i. Calibration: R2=1.00000 (5 ppm, 1 ppm, thru 0)
    2. Alternate CMS-2 Standard (7 ppm)
    a. Au (267.959 nm) = 6.31 ppm (90.1% recovery)
    b. Au (242.795 nm) = 6.31 ppm (90.1% recovery)

    Note: 1 ppm = 0.0001 wt% or 1000 ppm = 0.1 wt%

    Great care was taken in the experiment to minimize “false positive” results. This is why two different wavelengths were used for each element and a “check” sample was used. However, it is still possible that some interference from elements in the unknown sample contribute to some of the signal observed.

    The following was from the lab owner,

    Buckyboy,
    Given this was an acid digestion (not hydrofluoric acid) of black sands, the sample probably has at least 50% more gold in it. Aqua regia isn't going to break up or dissolve the sand (silica) so there could be gold encapsulated in the sand grains. Given that, you have to do some calculations to see if it is worth it.
    Regards,

    So if anyone can help break down this info I will look forward to your feed back. Thanks Mucho, Buckyboy!

  2. #2
    us
    Sep 2008
    46
    1 times

    Re: Help with Assay results as it relates to fine gold recovery from earlier thread

    34 ppm equals one oz. per ton. Extrapolate that and add that to your take through your regular gravity methods. Subtract costs for time, equipment, shipping of 3 1/2 tons per week to your local (!) refining entity who can hopefully drag a bit more pay out of it than your assayer did and see how you come out. Probably should bite the bullet, go with gravity methods, and shoot for volume. Either that or go ahead and put in some cool cyanide leach pits on site. Bit of humor there, but I actually do think the cyanide leach pits are kinda cool. They should be more plentiful, we have the technology. Small scale miners generally will not profit from values locked up in black sands, transport and refining will kill ya. Let them go and good luck. c

  3. #3
    us
    Mar 2003
    Redding,Calif.
    5,846
    6662 times
    All Types Of Treasure Hunting

    Re: Help with Assay results as it relates to fine gold recovery from earlier thread

    Sorry to tell ya this but all that work and money thrown in the toilet. #1 rule of a ASSAY is -NEVER HIGRADE SAMPLES- all you get is extrapolated bs and not a comprehensive analysis. No not never,multiple ROUGH samples only-John

  4. #4
    us
    Nov 2009
    27
    2 times
    All Types Of Treasure Hunting

    Re: Help with Assay results as it relates to fine gold recovery from earlier thread

    Hoser & Chadrack,

    The truth will set you free and I thank you for that. The cost to me was a lot of time, a little $ but worth it for the experience. I built a portable classifier that works really well, and other equipment to take on my next mission.

    If you ever watch Gold Fever on the Outdoor Channel you may remember the guy that was working nothing but fines from the San Gabriel Mountains. He sluiced as much as he could and pulled out black sands with a magnet. After he worked all of the gold out he put his black sands in a makeshift ball mill with some mercury and pulled out an impressive amount of gold as a result. "Small scale miners generally will not profit from values locked up in black sands" lot of truth to that but if you have a lot of time and can keep costs down may be worth it. Not completely giving up yet, will work through a couple hundred pounds of material I have here and let you all know the results before throwing in the towel.

    all for now over and out


  5. #5
    us
    Mar 2003
    Redding,Calif.
    5,846
    6662 times
    All Types Of Treasure Hunting

    Re: Help with Assay results as it relates to fine gold recovery from earlier thread

    Never EVER said to give up--just for ACCURACY a proper analysis procedure is a absolute imperative-then you have a REAL world answer to your GREAT question and the info to go ahead or buy a beer and relax-thats all-John

 

 

Home | Forum | Active Topics | What's New

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Search tags for this page

assay black sands

,

black sand assay

,
black sand assay results
,

black sand assay ton

,
does 34 ppm equal 1 ppm in assay gold
,

gold assay good bad

,
gold mining what is a good asay
,

how to get best assay on gold

,

what are good gold assay results

,

what is a good gold assay

Click on a term to search for related topics.
Powered by vBadvanced CMPS v4.3.0