* User Info

Welcome, Guest. Please login or register.
Did you miss your activation email?

* Who's Online


Dot Guests: 116 | Dot Users
Dot Hidden: 0

* Board Stats

  • stats Total Members: 12649
  • stats Total Posts: 125198
  • stats Total Topics: 17428
  • stats Total Categories: 5
  • stats Total Boards: 48
  • stats Most Online: 814

* Advertisers

Author Topic: WORKING BLACK SAND and SULFIDES in GOLD RECOVERY  (Read 14189 times)

0 Members and 1 Guest are viewing this topic.

Offline Seeker

  • PPT Invited
  • *****
  • Posts: 310
  • Province/State: BC Canada
  • Kudos: 9
« on: November 10, 2006, 07:15:59 PM »

Here’s How You Do It

Getting up to 90% of your Sulfide Gold out of the Black Sand Concentrates

1,[FOR STARTERS] What you'll need to process Black Sand Concentrates.
one #12 classifier...
one #20 classifier...
two gold pans...
wash tub....
few 5 gallon buckets...

The balance of this copyrighted, original article can be found at:
Gold Fever -- Part 2

Offline Steppegold

  • Full Member
  • ****
  • Posts: 74
  • Province/State: Ulaanbaatar, Mongolia
  • Kudos: 7
« Reply #1 on: November 11, 2006, 03:26:12 PM »
Hi Seeker - nice post.
I've got a question fro you. Would oxalic acid work instead of cider vinegar or citric acid?

It seems a shame to waste the cider! And we can't grow citrus fruits here in Mongolia, but - and here you'll learn something new - Mongolia is the gene capital of the world not only for the HORSE, ASS and CAMEL but also for rhubarb!

The reason the horses, asses, camels and for that matter goats and sheep leave the rhubarb alone is that, as everyone knows, the rhubarb leaves are full of poison, aka OXALIC ACID.  If you want a cool way to clean rusty limonite off quartz etc, then just dig up some rhubarb from Outer Mongolia or buy it from your local store. Then in an aluminium pan boil the stems in water to eat, and in a DIFFERENT aluminium pan boil the leaves with some rusty quartz.

After half an hour not only will the quartz be clean but the aluminium pan will also be sparkling clean as the oxalic acid dissolves the dull aluminium oxide off the inside of the pan. Oh, and you'll also find that there is enough oxalic acid in the pan with the stems that that pan is also the cleanest-clean-its-ever-been on the inside.

So, enjoy the rhubarb stems, together with the trace of oxalic acid (no-no for kidney stones!!) and trace of aluminium metal poison.

But don't drink the rhubarb leaf water or you'll be pushing up the daisies (ie dead or worse). Throw it away in the garden but wow the quartz looks is as clean as mother nature intended.

Thats enough rhurbarb- but does OXALIC ACID do the trick for gold recovery?

Offline Seeker

  • PPT Invited
  • *****
  • Posts: 310
  • Province/State: BC Canada
  • Kudos: 9
« Reply #2 on: November 11, 2006, 09:46:53 PM »
I've heard a method for recovering gold from solution by means of adsorbing the solution onto a silica-containing catalyst to form a gel, reducing the gold with oxalic acid, removing the precipitated gold by washing, and recycling the catalyst and any unused reducing agent immediately to the adsorption step; recovery is allegedly greater than 99% effective.

Found this on the net...


A solution of 5% gold was prepared by dissolving gold chloride (HAuC1.sub.4 .3H.sub.2 O) in a suitable amount of water. Dry sodium silicate gel powder was added in an amount of solution sufficient to hydrate all of the dry gel. The excess solution was poured off so that the level for the solution equalled the height of the gel. Saturated oxalic acid solution was added in an amount equal to approximately one-half the volume of the gel and the test tube covered with film to prevent evaporation. Upon completion of the reduction reaction, the suspension turned purplish-brown in color, and the solution was swirled and decanted. The decanted solution was then filtered to remove the elemental gold dust. Purity of the recovered elemental gold was 99.99%; 100% of the gold in the feed solution was recovered.

The gold solution may have any concentration of gold attainable and it may be a gold solution of water or alcohol. The amount of silicon-containing compound used is not critical but must be in an amount sufficient to act as a suitable catalyst for the reducing agent to reduce all of the gold present. Although the oxalic acid used was a saturated solution, a more dilute solution may be used so long as enough oxalic acid is used to reduce all of the gold present; however, a more dilute solution will take more time for the complete reduction to occur. Various mechanical means may be used to separate the gold from the solution or gel.

The following additional tests were made using the identical procedure as that used for Example 1:

    No.   Reductant          Metal   Catalyst

    2     Cinnamic Acid
                                   Gold    Gypsum-bound silicate (Na+)
    3     Cinnamic Acid
                                   Gold    Silicic acid
    4     Tartaric Acid
                                   Gold    Gypsum-bound silicate (Na+)
    5     Tartaric Acid
                                   Gold    Silicic acid
    6     Citric Acid           
                                   Gold    Gypsum-bound silicate (Na+)
    7     Citric Acid   
                                   Gold    Silicic acid
    8     Oxalic Acid
                                   Gold    Silicic acid
    9     Oxalic Acid 
                                   Gold    Grade 7, Chromatographic silicate
    10    Oxalic Acid
                                   Silver  Gypsum-bound silicate

Examples 2 through 9 gave good yields of gold, the best yields being obtained using oxalic acid as the reductant and gypsum bound (Na+ ) silicate as the catalyst. A good yield of silver was obtained in Example 10.

It can be seen from the above that a useful method for effectively removing gold or silver from solution which avoids the use of toxic or expensive chemicals, and mitigates waste disposal and pollution control problems. Further, provides a closed-circuit, high yield, short step process allowing control of the resultant particle size.