Duracell alkalines leaking?

I got the wrong formula, Potassium Carbide, K2C2 instead of Potassium Carbonate, K2CO3.

However, if it was the carbide, then it would release Acetylene when combined with water. This was use in carbide lamps and is still preferred for some cave explorations. See

Carbide lamp From Wikipedia, the free encyclopedia

More background info:

Edmund Davy first made acetylene in 1836 from a compound produced during the manufacture of potassium from potassium tartrate and charcoal, which under certain conditions yielded a black compound decomposed by water with considerable violence and the evolution of acetylene. This compound was afterwards fully investigated by J J Berzelius, who showed it to be potassium carbide.

He also made the corresponding sodium compound and showed that it evolved the same gas, whilst in 1862 F. Wohler first made calcium carbide, and found that water decomposed it into lime and acetylene.

It was not, however, until 1892 that the almost simultaneous discovery was made by T. L. Wilson in America and H. Moissan in France that if lime and carbon be fused together at the temperature of the electric furnace, the lime is reduced to calcium, which unites with the excess of carbon present to form calcium carbide.

Other carbides which yield acetylene when brought in contact with water are those of potassium, sodium, lithium, barium and strontium, but calcium carbide is the most economical to produce and use.

Pity I got the compound mixed up. It would have made a wonderful way to make small explosions:)

Because after cleaning, it starts to corrode again. If the base metal is steel, I get rust. If there's some residual potassium hydroxide, the green/blue/white crud (mostly potassium carbonate) begins to form, resulting in intermittent connections. I've found that silver plating tends to slow down or stop the corrosion.

The KOH reacts with CO2 in the atmosphere and forms K2CO3 (potassium carbonate) and water. A weak acid will clean off both any residual KOH, while warm water will clean off the K2CO3.

I can see some gas bubbles forming when I clean off the crud. I thought it was H2 (hydrogen) but C2H2 (acetylene) is possible. You're tempting me to dig some rotten batteries out of my "to be recycled" bin, spray on some white vinegar, and see if I can ignite the gas. H2 burns with color, but low temp acetylene should produce some soot.

Vaseline attacks rubber seals. Silicone grease (not silicon grease) is probably a better choice.

Vaseline liquefies at 99F (37C). Get it warm enough and it will drip like mineral oil.

It's also flammable and makes a nice fire starter.

In many cases, the battery contacts can be removed and replaced: More: Such hardware is available at all the usual online places.

Long ago, I tried Vaseline on automotive relay contacts. Most were switching several amps of DC at 12V. They worked nicely for about two years, and then slowly failed one after another. The problem was that the arcing had turned the Vaseline to carbon, which created a resistive connection. I suspect that I may have used to much Vaseline where a spark caused it to ignite. It might have worked with a thinner layer.

Drivel: "How to convert a Lead Acid Battery into an Alkaline Battery" I haven't tried this (yet).

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

All is not lost. You can smear some Vaseline on a cotton ball and make a usable fire starter: No explosion, but it would probably cause a greasy paper label inside the battery compartment to burn (until it runs out of air). Bouncing the unit around until the battery contacts produce a spark should serve as a suitable igniter.

Meanwhile, if you really want an explosion, I recommend one of the Lithium Ion battery based explosive and incindiary devices: "Don't Blame the Batteries For Every Lithium-Ion Explosion"

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I've often seen 'recipes' for certain compounds where they speak of carrying out this or that reaction "in the presence of" [some other chemical, often an acid]. I've always wondered what the hell that "in the presence of" actually meant. It doesn't seem very scientific since there's no quantative info ever given. Since you seem to be clued-up in this field, have you any idea?

In the manufacture of calcium carbide, it's a mixture of coke and lime being heated in a carbon arc furnace using graphite electrodes: The carbon comes from both the coke (coal) and the graphite electrodes. I guess(tm) "in the presense of" is a reasonable substitute for a complexicated explanation attempting to describe how the carbon enters the reaction.

More detail: "Calcium Carbide Manufacturing"

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Sorry, Here's a better article. Check figs 4 and 5 showing contact resistance dry and with mineral oil:

Yes, Thanks. You have sharp eyes.

I have a lot of trouble with typos. I lost several keyboards to coffee spills, so I started using Logitech K310 washable keyboards:

K310/dp/B008D1JRIO

They are small and don't take up much desk space, but the keys are too close together and very difficult to type on. So I spend most of my time looking for typos.

You are correct about the formula. I eventually found it also, and started looking for more information on the CO2 concentration, pressure and temperature used. I found the process is seldom used, and most companies have switched over to a liquid process involving potassium chloride.

So I wonder, how efficient is the potassium hydroxide process? I can imagine the industrial process would use 100% CO2, and raise the temperature and pressure to the highest level they could to speed up the reaction.

However, in our situation, we would only have atmospheric pressure and room temperature. The CO2 concentration is 400 ppm, which is only 0.04% by weight. So I don't think much potassium carbonate would be produced.

The conclusion is clear. Remove all batteries from unused equipment. Treat any corrosion from leaking alkalines with vinegar. The vinegar neutralizes potassium hydroxide, and the water in the vinegar would dissolve any potassium carbonate, where the acetic acid would neutralize the alkaline solution.

Wash any residue with plain water and allow to dry. Then coat with a liberal dab of vaseline to protect the contact surfaces and provide an extremely low contact resistance. See Figs 4 and 5 in

On 12/3/2017 2:03 PM, Jeff Liebermann wrote: [snip]

Silicone spray and grease has worked well for me in contact/wiper situations. Apply it, rub it in, wipe off the excess. Worked well on silver contacts and copper pads on pcb pads where the gold had worn off.

A bit more on whatever manufactories are using as a substitute for mercury in alkaline cells. The basic problem is how to get rid of the hydrogen gas produced by zinc corrosion that pushes the electrolyte out the valve.

Duracell's Aarschot plant in Belgium making alkaline AA batteries: At 3:09, the machine adds "secret performance enhancers" to the zinc.

I suspected that suitable mercury substitutes had been patented:

"Alkaline battery" "...an oxide or hydroxide of indium, lead, gallium, bismuth."

"Alkaline battery, manufacture thereof, and appliance using alkaline battery" "An inhibitor selected from an indium compound, lead oxide, a hydroxide of alkali earth metal, and polyoxyethylene alkylamide is added to an electrolyte or a negative active material. Hydrogen gas evolution is retarded and deterioration in performance is prevented."

"Alkaline battery without mercury and electronic apparatus powered thereby" "the negative electrode contains one or more indium compounds selected from the group consisting of indium sulfate, indium sulfamate and indium chloride." This patent has a good but rather lengthy description of the problem, alternatives, and solutions.

My guess(tm) is that indium sulfate, sulfamate, or chloride might be the "secret performance enhancers".

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I use silicone spray a lot. For example, did you know it works wonders on your seat belt to make it softer and slicker and a lot easier to extract? And it slides right back in when you leave your car.

But the feeling I get when I rub my fingers is completely different from vaseline. So I wonder if silicone spray or grease would clean electrical contacts the same way vaseline does.

Vaseline also creeps a little, so it self-repairs when connectors are removed and replaced. I wonder if silicone grease would do the same.

Finally, mineral oil, a close relative of vaseline, has documented effects reducing contact resistance in fretting conditions. See Figs 4 and 5 in

Although I found a significant reduction in contact resistance on plain tin/lead contacts using vaseline. So I feel I already know what silicone spray will do, but I need to get some silicone grease and see what effect it has on contact resistance compared to vaseline.

Thanks for the reply, Jeff. It's always a pleasure to chat with you.

I live in Ontario, which is the rust capital of the world. I have never seen such intense rusting anywhere else when I lived in the states. All my tools start rusting immediately when I moved back here. I found that a rust converter made by Rust Check saved my equipment. This product contains tannic and phosphoric acid. These change rust into ferric tannate and ferric phosphate. The feric phosphate is very hard and turns the steel black. It never rusts again. I would be lost without it. Here's the product as sold in Canadian Tire:

0477964p.html

Blue and green indicate copper compounds. Potassium carbonate is white:

There are a few more options:

1. Plate with copper or nickel

Copper and Nickel plating at home

1. Use Rust Converter shown above

1. Remove rust and coat with vaseline

The K2CO3 dissolves in water from the vinegar, then the acetic acid neutralizes the solution.

However, I really don't think much K2CO3 is produced. The reaction is at normal atmospheric pressure and room temperature. The CO2 concentration is

400ppm, which is 0.04% by weight. Contrast this with industrial process, where the CO2 concentration is 100%, and the temperature and pressure are raised to the highest level possible. I think in our situation, the amount of K2CO3 is negligible.

This turns out to be completely false. I grabbed the wrong formula: K2C2 instead of K2CO3. There is no potassium carbide in leaking alkaline batteries.

I'm concerned silicone grease may not give the true metal-to-metal contact that vaseline gives, but I will have to try it. See Figs 4 and 5 in

As far as rubber seals, there should be none around battery contacts. Most o-rings do not use natural rubber.

From Stack Exchange:

tl dr - Have no fear of Vaseline and o-rings

O-rings are made out of many different materials. I would suggest that those o-rings which are made to work in the automotive realm are made to be resistant to things such as oil, gasoline, and other petroleum products. This would include Vaseline. While Vaseline and other petroleum products may degrade real rubber (actually made from the rubber tree), current o-rings technology does not use natural rubber. The Parker O-ring Handbook states:

A polymer is the "result of a chemical linking of molecules into a long chain-like structure." Both plastics and elastomers are classified as polymers. In this handbook, polymer generally refers to a basic class of elastomer, members of which have similar chemical and physical properties. O-rings are made from many polymers, but a few polymers account for the majority of O-rings produced, namely Nitrile, EPDM and Neoprene.

Looking throughout the matrix you can see that natural rubber does very poorly against oil, while Neoprene does fair to good and Nitrile does excellent. (Note: Even though EPDM is said to be used as one of the big three substances, I'm not finding it on the list.)

With this in mind, you should have no worries about whether to utilize Vaseline on any of the o-rings. Vaseline is a very mild petroleum product. If it wasn't, we wouldn't use it in so many products which involve skin care. If o-rings were actually made of rubber, then there would be concern.

rubber

If you can remove the damaged contact and replace it with these, that would be the way to go. Just apply a liberal coat of vaseline to protect the contact and provide a very low contact resistance.

Vaseline is not for arcing contacts. It burns as you have found out.

It appears he hasn't yet either:)

I don't think he understands the chemistry of alkaline batteries.

Nice thanks. (Mineral oil, good.) My usb thumb drive to 'scope connection treated with WD-40 is still working fine.

George H.

Some people claim WD-40 is basically kerosene, which is a poor lubricant and tends to evaporate:

Next time, try vaseline. It is ideal for USB connectors.

So when have I bought those?

--
Regards, Joerg 

http://www.analogconsultants.com/

Iron phosphate is white. It makes a neutral paintable surface. It's the tannate that's black. It's what (used to be?) used to print newspapers. Tannic acid is an excellent anti-oxidant.

Typical of you. Rather than man up and admit that you were wrong, you try to change the subject. No one mentioned you buying them until your last message. You claimed that you hadn't SEEN them.

I have read that silicone greases and oils (and even their vapours) turn into a deposit of insulating glass on sparking relay contacts, which makes them unreliable. The story was that silicone floor polish was banned in phone exchanges for this reason.

Relay manufacturers do warn about this. Search the following documents for the word silicone to see the warnings:

You have to search this one for the word silicon, as they forgot the e on the end when translating from Japanese I guess:

The usual reason is to initiate the reaction but then playing no further part - IOW acting as a catalyst. It won't work without a trace of the acid but how much makes little difference to the outcome.

Lots of chemical (and biological) reactions only work at the right pH acid or alkaline. Some reactions are very fussy.

The other common family are peroxide initiators for free radical polymerisation reactions where the resin is shipped with an inhibitor and you add a few drops of peroxide and mix it in prior to use.

Trace mercury was used in batteries to discourage them from gassing back in the days before they found safer alternatives.

--
Regards, 
Martin Brown

When have I seen them, and where?

--
Regards, Joerg 

http://www.analogconsultants.com/