SMB

[FrugalRefiner]

From the introduction in my versions of Hoke's book:

Evaporation - Hoke discusses reducing the volume of solutions in various
chapters throughout the book. This process is known as evaporation. In
other areas, she writes about boiling solutions for various reasons. It is
important to understand the difference. Boiling is used in processes like
dissolution and washing. When a solution containing values is being
boiled, the vessel should be covered with a watch glass or be otherwise
similarly contained. Boiling creates tiny eruptions at the surface of the
solutution as bubbles pop, and can propel values out of the vessel. The
watch glass captures these minute droplets and causes them to drop back
into the vessel. When evaporating a solution to reduce its volume, the
solution must be kept below the boiling point to avoid any bubbling
which could cause a loss of values, as the vessel is not covered during
evaporation. Do not boil when evaporating. (page 44, 57)

Dave

 

[steyr223]

Exactly whay i mean

Evaporation - Hoke discusses reducing the volume of solutions in various
chapters throughout the book. This process is known as evaporation. In
other areas, she writes about boiling solutions for various reasons. It is
important to understand the difference
Boiling is used in processes like
dissolution and washing.

----------***************
When a solution containing values is being
boiled, the vessel should be covered with a watch glass or be otherwise
similarly contained
----------***************

. Boiling creates tiny eruptions at the surface of the
solutution as bubbles pop, and can propel values out of the vessel. The
watch glass captures these minute droplets and causes them to drop back
into the vessel. When evaporating a solution to reduce its volume, the
solution must be kept below the boiling point to avoid any bubbling
which could cause a loss of values, as the vessel is not covered during
evaporation. Do not boil when evaporating. (page 44, 57)

Yes i have read this many times
Sorry if this is interrupting the original thread
This brings up a whole new subject
When asked mutiple times if covering during evaporating impedes the process the answer has been no but she says not to cover
I will attempt yo find the thread but one of the major contributors of this form says many a times it is ok if you cover
I am not trying to be difficult i am just ttrying to understand :mrgreen:

Göran it's not that i want to boil this is not a problem anymore as i add only the right amount of nitre now( i only
Needed to evaporate once for 26 hrs to never whant to again)
But it is much easier to turn up the flame and walk away
Thanks steyr223 rob

 

[g_axelsson]

...
When asked multiple times if covering during evaporating impedes the process the answer has been no but she says not to cover
I will attempt yo find the thread but one of the major contributors of this form says many a times it is ok if you cover
I am not trying to be difficult i am just trying to understand :mrgreen:

Göran it's not that i want to boil this is not a problem anymore as i add only the right amount of nitre now( i only
Needed to evaporate once for 26 hrs to never want to again)
But it is much easier to turn up the flame and walk away
Thanks steyr223 rob

To cover up while evaporating is totally wrong, it diminishes the evaporation.
Instead of cranking up the heat, remove the cover, use a low and wide vessel (for example an evaporating dish) and put a fan blowing air past the opening of the vessel and it will go a lot faster.

Göran

 

[steyr223]

Thanks Göran
I do exactly that or did exactly that even though i was
Confused i considered it a more logical approach
But thanks now idont have to wonder

Back on track sorry
Thanks steyr223rob

 

[freechemist]

Can you remember the loud, whistling sound, created by the boiling contents of a overheated teapot, the softly simmering sounds of the same pot, heated cosily on a stove? - Both sounds originate from gaseous water (water-vapour), escaping through a small opening at the top. Hearing them, means becoming aware of an ongoing process of evaporation.

The boiling point of a liquid is defined as the temperature, e.g. displayed by a thermometer, placed in the gas-phase over a boiling liquid substance, in equilibrium with 100% of the given substance in the gas-phase, at a given pressure. Thus:

-The process, creating the sounds of the teapot, is commonly called "evaporation".
- Covering e.g. a beaker with a watch glass, while boiling it's contents minimizes losses due to splashing, but does not make evaporation impossible.

 

[Pantherlikher]

I see both points...To boil or not...
Boiling as Harold said a few times allows bubbles to burst, atomizing PMs which can escape with the evaporating liquids.

I don't know about you but if there is a possibility of loss, I'd rather go the safe route.

I'm also working on using a projection screen TV lense as a heat magnifier.
Experimenting with solar heat. I'm building a heater for the swimming pool as well as evaporation. Depending on how much heat I can generate at the focal point using mirrors.

B.S.

 

[steyr223]

Freechemist. Hows the projecting going (seems like you
Always have something goin on

Pantherlikher



I have 2 more. With stands so they can spin as to track
The sun

I attempted to heat up borax in a dish
It worked but only kept one part molten while
The rest was not

I guess if i had a melting dish the size of a dime and
Actually put it exactly at the focal point...........46inch,,,,........

I am also working on a microwave gun :mrgreen:

Steyr22 . Rob

 

[Pantherlikher]

Nice...
Automatically tracking the sun is what stumps me. I can't afford to go buy something so I'm deep in thought about a substitute.

I also have thoughts about using mirrors from the focal point to a centralized burn spot.
Just ideas bouncing around the vast emptiness of the brain pan.

B.S.

 

[Anonymous]

For excess Nitric I either use a pre weighed amount of gold to use up Nitric and/or I use Sulfamic acid.

Frankly the Sulfamic acid works pretty effectively so I don't have to evaporate down, use sulphuric, or any other other methods mentioned. I add Sulfamic until there is no reaction even on vigorous stirring and then leave for half an hour. Don't worry if there are crystals left over in the bottom because you'll then be filtering it before dropping it.

It's a right royal pain in the behind learning to get the right amount of Nitric especially if you're trying to dissolve your product rapidly and don't have days to wait but it does come with experience OP so don't worry. I would guess that every single guy on this forum has overcooked it on the Nitric more than once so do you're not alone.

Regards

Jon

 

[steyr223]

Curios
I had always just added a pinch of sulfumic
But spaceships you say add till reaction is done
When do you add when still hot on the burner

What would the actuall chemical reaction be for this
I mean what actually happens
H2s04 +Hn03

Thanks steyr223 rob

 

[goldsilverpro]

Curios
I had always just added a pinch of sulfumic
But spaceships you say add till reaction is done
When do you add when still hot on the burner

What would the actuall chemical reaction be for this
I mean what actually happens
H2s04 +Hn03

Thanks steyr223 rob

Theoretically, it takes about 1.54g of sulfamic acid to treat 1ml of 70% HNO3. Sulfuric acid and nitrous oxide (laughing gas) are produced.

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=10799&p=105096&hilit=sulfamic+acid#p105096

 

[rich_2137]

Thanks for all the advice guys! :-D

 

[steyr223]

Thats a lot of sulfumic
So i take it, spaceships,
You would have to be getting pretty darn
Close

Thanks gsp
Steyr223 rob

 

[goldsilverpro]

Thanks, Rob.

It's all on here Rob. You just have to look for it.

 

[jason_recliner]

I'm still in the process of recovering my first solution(s).
I've added SMB to one of my more recent AuCl attempts, and watched nothing happen at all. I know it probably has way too much NO3 in it. But not even an initial drop. I kind of expected that anyway, having read about excess nitrate, and was surprised to read the above post about it dropping and slowly redissolving.

Now, will the added SMB (or part of it) slowly evaporate out at room temperatures? That is, either the sulphur leaves and the sodium remains, or does it all go, or all stay? I ask because it has a smell, which suggests it's slowly leaving.

Also on the subject of evaporating nitrate. I have a Goran/Jason coffee maker but don't currently have anything resembling a watchglass. Why the watchglass if not boiling it? If hot (say 80-90°C) vapours hit the colder watchglass, will they not just condense and drop back into my solution? Wouldn't it be better to let it all out, as long as I'm not also boiling away my gold?

There's talk about both sulfamic and sulphuric. I have ready mixed sulphuric battery acid tucked away somewhere. Is a few drops of that useful?

[Edit: Oops. Didn't realise there was more than one page of forum replies when posting this. Some questions already answered. Don't use watchglass. Sulphamic, not sulphuric. Still interested about the SMB.]

 

[solar_plasma]

@jason

Still interested about the SMB

Maybe there are more factors,I don't see right now, but those different observations can be explained by the speed of reaction, which increases with concentration and temperature. So, higher concentration of excess nitric and higher temperature might redissolve the gold before it is even visible. Also the concentration of gold, contaminants, the amount of smb and even sunlight will influence the speed and quality of reaction.

I think until now I had only few precipitations, that looked completely similar. Typically only, if the solutions are quite clean, really free of oxidizers and have comparable concentrations of gold.

 

[g_axelsson]

If you need a watch glass (not for this occasion though) then just use a saucer, preferably a glass one. Great to keep the nitric in when dissolving gold or platinum. Just as you say, it condenses and drops back into the reaction. A type of reflux process.

Göran

 

[Clneal2003]

I'm not saying I haven't done it before , I've been successful s few times with AR and I do understand the process I've just never came across this before so I've had no need to research it, Sorry if I'm not allowed to ask for a little help and you seem to be going off what my original question was but in don't matter now anyway!

Hi rich, dont be discouraged, try the sulfamic acid to get rid of the extra nitric, then try drop with smb again
remember that it only takes about 1ml to dissolve 1 gram of gold of excess nitric in AR

the next time you make your AR ad the nitric slowly with a pipette or eye dropper

Odd question. I just got my first bottle of CP Nitric and before I get busy... I wanted to know if Nitric will dissolve a plastic pipette? I know it doesn't play nice with some plastics.

 

[Geo]

High density polymers hold up better to nitric acid than just plain rubber. HDP is the material trash bags are made of. Most clinical pipettes are made of HDP so unless it's something I have never seen before, any clinical pipette will work for nitric acid usage.

As an aside, spaceX's "space ship 1" uses ground up rubber tires and hot nitric acid as its main fuel source.