Small Scale Treatment of PM Sulfide Ores

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Reno Chris African mining "secret": Gold PGMs including their sulfide forms and Diamonds all stick to vaseline petrolium Jelly. Make a simple sluice box with a plastic sheet layer in the bottom and coat it with a layer of vaseline. low angle slow water run your crushed ore over it. Re- run ore to make sure you got most all of it and the remove the plastic sheet scrape off the vaseline with a plastic paint scraper and thin the vaseline with acetone till watery consistancy the metals will drop to the bottom of your comtainer. de cant the fluid. put in a fireproof metal container ... stainless steel bowl. light on fire to burn of vaseline / acetone residue and process from there as you wish. Sounds wierd but it works well. Best of success in your efforts. Ron
Works on Sapphires also. :)
 
rhwhite67 said:
Reno Chris African mining "secret": Gold PGMs including their sulfide forms and Diamonds all stick to vaseline petrolium Jelly. Make a simple sluice box with a plastic sheet layer in the bottom and coat it with a layer of vaseline. low angle slow water run your crushed ore over it. Re- run ore to make sure you got most all of it and the remove the plastic sheet scrape off the vaseline with a plastic paint scraper and thin the vaseline with acetone till watery consistancy the metals will drop to the bottom of your comtainer. de cant the fluid. put in a fireproof metal container ... stainless steel bowl. light on fire to burn of vaseline / acetone residue and process from there as you wish. Sounds wierd but it works well. Best of success in your efforts. Ron
Works on Sapphires also. :)

What purpose does this procedure have in treatment of sulfide ores? That is, after all, the purpose of this thread.
 
The purpose of this vaseline sluice process set-up would be a way to simply and easily concentrate the sulfides from the crushed ore as after crushing it replacing the shaker table Chris said he would like to use here in @2 of he post with something just as effective and a whole lot less expensive and if he re-runs the material a couple of times he will capture virtually all of it. No matter what else you do to process sulfide ore the next step after crushing is concentration of the ore. Most large companies do this through flotation or as Chris mentioned a bank of tables. For us small guys on a budget this is a really good alternative that works well.
Ron


2. Reduce the bulk of the ore.
My 200 pounds of ore is a lot of rock to deal with. I will concentrate it down to the heavy components. Sulfides are generally dense minerals and gold is as well, so I will concentrate using a specially made sluice system. I wish I could use a shaker table, but these are several thousand dollars to purchase, an amount much more than I want to spend on this project. Yep, I will lose some, but I do not have infinite monetary resources. The ore has a 5 to 10 percent sulfide content, so I expect about 10 to 20 pounds of sulfide concentrate. Dealing with 10 to 20 pounds is a lot easier than 200 pounds. There will be some loss of values in this operation - but I accept this because although the method is less than optimal, it's the best I can put together.
 
Reno Chris said:
I cant believe that its been that long - I've made more plans and done only a little. toward moving this to reality.

I really need to work on this, hopefully when the weather here improves.

Also, I now plan on doing a full Youtube video of the entire process.

I find this thread very interesting. Thank you. Also, what is your YouTube channel?

thanks again
 
Here is a video I have done on Youtube on using a metal detector to find gold:
https://www.youtube.com/watch?v=sA2feW5XOFM

If you go there you can subscribe or sign up for my you tube channel.

I have gathered now 166 pounds of free gold type gold ore, some of which has visible gold in the rock. This is 1/12th of a ton. In the next month or so, I am going to do a video on taking that gold ore rock all the way to a button of metallic gold.
 
Hello Chris,
One comment on your original plan to process a sulfide ore, don't use a HEPA filter for protection from fumes.
Fumes are vapors, which should go right through a HEPA filter. A canister type of filter with activated carbon would be best.
JCDOG
 
solarsmith said:
your crushing milling goal should be 80% passing -200 I have made a ball mill that can do about 300 lbs an hr. since you have a sufide type ore you should be looking at processing via a floatation cell or column . I will not try to convince you as to method but id you look up someing caled the (75 ways of gold concentrating) your answer will almost certainly be there. Its the best info on methodes for finding grind size for each way od slucing or floating ore. good luck Bryan in denver [email protected]

Found that 75-Gold-Recovery-Methods book on Scribd:
https://www.scribd.com/document/281938063/75-Gold-Recovery-Methods

Also found a similar copy here with some of the same info "Fine Gold Recovery – Alternatives to Mercury and Cyanide Purpose of study":
https://www.researchgate.net/profil...urpose-of-study.pdf?origin=publication_detail
 
This is an old thread, but relevant to my situation. I've got perhaps 700-800 pounds of high grade sulfide ore, that I collected from abandoned silver prospect sites. More is available. Grinding a very small sample, acid, filter, and precipitation showed there is indeed a goodly amount of silver present - lead too - and likely small quantities of many of the other sulfides present (I expect manganese from one site), and perhaps a little gold.

No deserts where I live. I'm a bit nervous about working with sulfides - especially roasting. As an alternative to roasting, I've read, after a fine grind - say 200 minus - then, in a open air vat, if I add a small amount of fertilizer, keep damp, and stir occasionally, that naturally occurring bacteria will remove the sulfur - likely taking a few months to do so. Or perhaps, I'm overly concerned; roasting 800 pounds of 'galena' (not much rock in much of this stuff), in small batches, might not disturb my flora and neighbors?

I wonder though, if I've gone the bacteria route, should I proceed with concentration and refining, just as if the material has been roasted, or do I have something else - something that should be concentrated (no shaker table or flotation cell available) and refined in some specific fashion?
 
The easiest way to treat your ore is to see if you can find some one who will toll treat or purchase the ore based on assays.

If you cannot find such an outlet, reasons may be nothing such exists locally or your ore is too low a grade or too small a volume, then you are stuck with treating it yourself.

Roasting the ore will result in an amount of pollution that neither you or your neighbours will be able to believe. Totally forget this approach unless you enjoy being closely attended to by the EPA.

Sulfide ores suffer from sliming when milled, provided you are willing to suffer high sulphide losses then milling and concentration is feasible.

Keep in mind that your ore sources are likely very limited so you do not want to be putting a lot of money into concentration methods which will get little use.

Bacterial leaching is not quite as easy as you say, pH, bacteria starter type, moisture content and temperature are some of the conditions which are important.

The easiest way to treat sulfides is to jaw crush them to the tightest setting on the jaw crusher, usually around 10mm.

Pile the milled material on a thick sheet of black plastic with a drain pipe at the bottom to send any liquid to a holding pond.

A 20% NaOH solution is sprayed from the holding pond pump over the top of the heap for 6 hours and then the pump is stopped for 1 to 2 hours, then the cycle is repeated.

This sequence is continued until the sulfides have all been destroyed, depending on the temperature and the sulfide type this can take from weeks to months to achieve.

Deano
 
Thanks Deano,

First - you've confirmed all my worst fears - that's a good thing - keeps me out of trouble.

Second - Many reasons I'd like to do this myself - chief among them: 1) learning and curiosity 2) The material is from several general locations and quite a few veins. I haven't done a good job of keeping it separated. If I can learn how do this in small bulk samples in the remote area I'm working, I'll be able to determine what is worth more attention.

Third - a small crusher and leach system sounds good. I lack some critical knowledge though. I've done some acid extractions, and selectively precipitated lead and silver from them. I have no idea where to learn to selectively precipitate, individually, or in some group for later separation, the metals the pregnant caustic solution might contain. Where might I research this?
 
The base metals which are most likely to be dissolved in a caustic leach are lead and zinc, tin will also dissolve but it is likely that any tin levels will be low, any other metals will most likely be present at even lower levels. Keep in mind that cobalt will also dissolve in alkali solution and cobalt often accompanies copper rich ores.

There are many pH solubility charts for various metals on the internet but it is difficult to get a clean separation by precipitation.

If you are just wanting to drop out any dissolved metals then it is easiest to do so as a bulk lot, if you are only using small amounts of ore for testing then the value of these metals is low.

The above comments also apply to selective electrowinning of the various metals.

Deano
 
Perhaps I should plan 2 leaches:

A base leach to remove the base metals - much lead, plus who knows what else.

Then follow with some other leach to remove the silver - hopefully separated and reasonably pure from everything else. I've read a lab analysis summary of this stuff, but i don't know what the input the was; that is, pure vein material, some form of concentrate, or a more bulk sample. The acid/precipitation test I ran looked real good. I'm doing this for the fun and learning - a lot of the fun though will be seeing/producing/having hundreds of ounces of silver when I'm done.

You say though "difficult to get a clean separation by precipitation", so I wonder if I'm thinking entirely wrong about this. I'm looking/thinking I want a small scale, DIY, practical (meaning a safe and decent but not best recovery) means to refine my 700-800 pounds of ore - and perhaps double/triple that quantity later if it looks financially attractive.
 
Deano said:
The easiest way to treat sulfides is to jaw crush them to the tightest setting on the jaw crusher, usually around 10mm.

Pile the milled material on a thick sheet of black plastic with a drain pipe at the bottom to send any liquid to a holding pond.

A 20% NaOH solution is sprayed from the holding pond pump over the top of the heap for 6 hours and then the pump is stopped for 1 to 2 hours, then the cycle is repeated.

This sequence is continued until the sulfides have all been destroyed, depending on the temperature and the sulfide type this can take from weeks to months to achieve.

Deano

Thanks again, I have a growing quantity of massive Ruby Silver, Acanthite and PGM sulfides and Antimonides to find a processing method for. Would a flood and drain system on a relatively thin bed (>4") of finer milled material speed this up a little for a smaller operator? Heap leaching on site isn't an option.
Breaking down the sulfides rather than roasting or trying to smelt directly sounds pretty good to me

Cheers Wal
 
If you are treating a small quantity of material then you most assuredly can do as you suggested with a thin bed system.

The crux of treatment is to subject the ore to alternating cycles of liquor and air, the method you use is limited only by your imagination.

Heating the leach solution will speed up the reaction with the sulfides, a small solar heating system will do a good job.

Note that all wetted components of the system must be stable in the presence of strong caustic solution.

Deano
 
Thanks, I'll try a sample and test it at intervals.
If I can remove the Antimony and Bismuth at the same time as converting the Sulfides would be good
Do the base metals drop as hydroxides/oxides in the leach reservoir as the Sodium Hydroxide becomes spent or is it necessary to add Sodium Hydroxide at regular intervals and maintain pH to keep them in solution?
I'm assuming any Silver Halides in the ore will be converted to Silver Oxide and I may put some of this into solution if the NaOH levels are too high.

Cheers Wal
 
Silver complexes are slightly soluble in caustic solution, you would need a vast amount of leach solution to have appreciable silver losses in solution.

If you are approaching saturation level for base metals in caustic solution then a drop in alkali level in that solution will cause the base metals to precipitate from solution.

Keep in mind that a drop in alkali level in the solution will also cause the solution to be less effective in sulfide breakdown, so you should keep a check on the alkali levels for this reason rather than for base metal saturation in the solution.

It would be an uncommon silver ore which has such high levels of alkali soluble base metals that they appreciably affected the breakdown of sulphides.

Deano
 
I have noticed several replies concerning thecorrect mesh sizes for extraction. The purpose of size reduction in ore processing is to reach a size range that gives you discrete particles of ore and of waste. Then a clean extraction can take place. Gravity separations are good down to anywhere from 60 to 100 mesh. Any smaller and hindered settling starts to take place or the slimes will just go with the flow (tables). Anything smaller than 100 esh is generally treated with froth flotation Sluice boxes can be highly effecient in recovering the heavy mineral being processed and can recover fine material but this is usually at the expense of larger sized material (nuggets).
 
Has anybody heard of flexicone technology for sulfide ores. They have been around for a few years now. If what they claim is true it sure would seem to change some things for mining sulfide ores
 
Very few sellers of recovery systems actually show assays of ore from before and after processing.
Being able to show concentrate assays is meaningless unless a set of tailings assays shows that the process has high recovery rates.
I do not think that any gravity methodology will cause sleepless nights for the flotation designers.
Each technology has its area of best use, gravity whether natural or enhanced gives best results on coarser feeds.
Originally, straight gravity separation was the only option for concentration of sulfides.
Use of a table allowed cleaner separation of concentrates and treatment of finer sulfides.
Flotation meant that the entire mining industry changed to using this technology virtually overnight such was the improvement in recovery and selectivity.
If you really think that going back to any form of gravity method to replace flotation is a good idea then best of luck to you.
If I absolutely had to use a gravity method it would be wilfley or similar tables set up with sized feeds.
Very slow to process with but the recovery is good and the cons are clean.
Deano
 
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