Non-Chemical Cleaning Glassware???

[dbrick81]

Would some one fill me in on a good way to clean glassware. I thought i had a beaker nice and clean, then went to dissolve some silver in HNO3. Next thing I know it starts precipitating silver chloride, and yes the day before I used the same beaker for HCl (but I thought I cleaned it well). I've heard some one say to clean the glass with acetone but this seems a little harsh to me. Any help would be great.

Thanks,

David

 

[lazersteve]

David,

I clean with hot soapy water, then rinse with lots of water. For silver I follow up with a rinsing spray of distilled that I dispose of before using the beaker.

For really stubborn organics Piranha works well (but it's dangerous).

Here's the wiki on Piranha:

Piranha

If you have precious metals clinging to the beaker try some of the usual reagents (HCl-Cl or AR) after wiping with a clean filter paper.

For general use plain tap water works fine.

With silver solutions be sure you use distilled water in the reaction or the silver chloride formation is inevitable.

Harold has mentioned using a non-abrasive cleaner, perhaps he will restate the exact one he used.

Steve

 

[Noxx]

BonAmi is used to clean glass without scratching it.

David, I may be wrong but I don't think the problem your glassware...

Was it technical grade nitric acid or homemade ?

 

[Lou]

It does not take much chloride anion to start precipitating silver chloride. You should have rinsed more with distilled water, at least 3 times. Tap water will leave a residue of chloride upon drying. Remember to swirl the water in the beaker and then invert so that the water coats the walls on its way out of the beaker.

Bon Ami works wonders, as does Alconox, which is the classic detergent-of-choice for laboratories.

For cleaning glass, it depends on what you want to do.
For non demanding work just a scrub with hot, soapy water will do the trick. Rinse it with distilled or deionized water and then dry.

Acetone and salt is a good trick to remove stuck on gunk. It's also a nifty way to dry glass out, although ethanol works well too.

If I am doing demanding work, I clean my glass in a dishwasher, follow with acetone-salt, rinse 3X with distilled water, heat in an oven at 340C for 2 hours, cool, and then rinse with hot aqua regia.


As for Piranha solution, there should be no recommendations for its use on this forum, as there are no situations that call for cleaning anything whatsoever with it. It is arguably one of the most dangerous compositions to use, and I do not sanction its use. It is extremely unstable!

There are many workarounds for it, most notably is the safer alternative ammonium peroxydisulfate and 18M H2SO4; very effective. Potassium permanganate and KOH is very good. Even chromic acid is a safer alternative to removing organics, but CrO3/H2SO4 is useless to us refiners because it contaminates your glassware with hard to remove chromium, and its carcinogenicity makes it an issue to handle and dispose. That further contaminates your precious metals.

Piranha is a last ditch option and it should be avoided at all costs because it is very easy to run into trouble using it. I've had accidents with it in a controlled laboratory environment with the best equipment and safety measures in place.

 

[Harold_V]

Harold has mentioned using a non-abrasive cleaner, perhaps he will restate the exact one he used.

Bon Ami

It doesn't harm the surface of glassware. I know of NO other (scrubbing) cleanser that can be used without harming glass.

Avoid using scratched containers for precipitation. Gold often clings tenatiously to the scratches. There are instances where I had to use AR to eliminate some, having grabbed the wrong beaker.

Harold

 

[Harold_V]

It does not take much chloride anion to start precipitating silver chloride.

I'm sure that's true, but how critical is it to the guy that is reclaiming gold in his garage, or his garden shed?

While I agree with your comments, from a practical standpoint, assuming the average guy is interested in producing gold of industrial quality, I am more than convinced that the use of distilled water is wasted energy.

I learned, long ago, to live with traces of silver chloride. They are generally eliminated in the final filtration, with the values recovered when the filters are processed. I never found an instance where it limited my ability-----and to my knowledge, I achieved full recovery. I had my slag assayed before discarding. Values were found to be so low that it was not worth re-processing by a firm that specialized in that type of operation.

Washing the resulting gold in ammonium hydroxide, for all practical purposes, eliminates any residual silver chloride that may have followed gold through the refining process.

I'm not suggesting, not for one moment, that using distilled water isn't a requirement for ultra high purity----but for the average guy that is likely to introduce more contamination to his product through handling and using dirty vessels, I see it's use as unnecessary. Frankly, he has a great deal more to be concerned with than the chance of introducing contaminants with his water.

How many actually use a good washing technique? Far more undesirable material is eliminated in that simple function than would be added by tap water.

I've said it before, and I'll say it again----my end product spoke for itself. How many do you know that can melt their gold powder without fluxing and have a bright surface? I used tap water exclusively for everything but test solutions and electrolyte for my silver cell , in spite of the fact that I distilled my own water, so it was readily available. I'd do the same thing all over again if I was still refining

I won't post the picture I post regularly---you've all seen it now. Proof positive that tap water works adequately (for most situations).

Harold

 

[Lou]

Indeed, I am spoiled in that case because I have it on tap.


Could also be that your tap water was/is far superior to tap water in my area. By no means should you think that tap water in Utah is the same as tap water in Ohio or in any other state. Logic would state that it would be federally standardized, but it isn't.


Lou

 

[SilverFox]

Logic would state that it would be federally standardized, but it isn't.

Lou

Careful what you wish for, Goverment often operate like they were coated in slick 50.
Situations like this, You can have your fedral mandate on water purity if you agree to this this this and this. Those other things may in the long run cost you more then the electricity to distill your own.

Harold never did specify whether the water used was from one of the follow sources. Well, City, Community well or lake stream water."

Hell if there is a natural gas drill somewhere within 5 miles of your well you could be facing the possibility of extra sediment in your well water.

 

[Harold_V]

Indeed, I am spoiled in that case because I have it on tap.

Could also be that your tap water was/is far superior to tap water in my area. By no means should you think that tap water in Utah is the same as tap water in Ohio or in any other state. Logic would state that it would be federally standardized, but it isn't.

I certainly agree with that. The water from our first well, here in Washington, was heavily contaminated with iron. So much so that we had to install a filter. The well didn't last long, once pumped dry, it produced water at a miserable quart/hour. Our new well, over 350' deep, lacks the iron, so our filter system is a bonus.

The water we had in Utah was not great, but the contaminants didn't report in the gold. Not everything will, as I'm sure you know.

When I ran my still, the buildup on the heating coil was staggering. I'd have to clean it after making 20 gallons. The buildup was so thick it came off in chunks. Lots of mineralization, but apparently little in the way of dissolved metals.

Water in Washington is known to be contaminated with manganese, although I have no clue how badly, or how commonly. I agree, there are instances where distilled water would be a requirement----just trying to enlighten folks that they may or may not need to go to the expense. If they refined on a large scale, it could prove costly.

Harold