Sciencemadness Discussion Board

calcium carbide from calcium chloride, magnesium and coal

BauArf56 - 22-5-2021 at 03:30

so i thought about an easy way to make calcium carbide from household items. I discovered that melting a mixture of calcium chloride (pellets for humidity) and magnesium turnings gives a blackish solid that react with water as calcium would do. As it react the water gets cloudy (calcium hydroxide), so this is probably calcium metal (Mg + CaCl2 → Ca + MgCl2). So now i thought to add some coal to the mix, so while calcium forms, it reacts with carbon and gives calcium carbide. Unfortunately i didn't do this yet, although it looks feasible. Any ideas?

Johnny Cappone - 22-5-2021 at 04:17

Even if it worked, I think you would at most get finely divided crystals of CaC2 that would react immediately with atmospheric moisture, since larger granules can only be formed when the substance is melted somewhere around 3,000 degrees Celsius.
Carbide is usually a widely available reagent. I have doubts about the economic viability of a production route that requires metallic magnesium. I have a microwave transformer that I found in the junkyard whose secondary was rewound in order to supply 38V, if i use it to open an arc with graphite electrodes close to a mixture of powdered graphite and CaO/Ca(OH)2/CaCO3, it usually yields some carbide. Production processes on an industrial scale are not always suitable for the amateur chemist, but this is one of them. As it was adopted by the industry, I am inclined to believe that it is the cheapest route as well. Anyway, try and report your experiments!

Alkoholvergiftung - 22-5-2021 at 05:00

From "Chemie und ihre Technologie".
For Carbide electricity isnt nesecary only engough heat. An reaction of
3CaO + 6C + 2Al (powder)= 3CaC2 + 2Al2O3.The Thermal heat of the Thermit reaction is enough for CaC2 production but it was never used because electricity is cheaper.I cant finde the text passage now but an frechn guy used magnesium instead.

BauArf56 - 22-5-2021 at 23:00

Quote: Originally posted by Alkoholvergiftung  
From "Chemie und ihre Technologie".
For Carbide electricity isnt nesecary only engough heat. An reaction of
3CaO + 6C + 2Al (powder)= 3CaC2 + 2Al2O3.The Thermal heat of the Thermit reaction is enough for CaC2 production but it was never used because electricity is cheaper.I cant finde the text passage now but an frechn guy used magnesium instead.


that's what i wanted! exploiting the high heat generated by the magnesium to make sure the calcium and carbon react.

For the electrochemical stuff, there would be the same problem with the reaction between magnesium and sodium hydroxide: although magnesium is less reactive than sodium, at high temp, it's able to reduce it (for a better explanation see this: https://www.instructables.com/Making-Sodium-Metal/). Anyway, i tried, but it's too hard to ignite, so i'm going to wait to get a new blowtorch...

[Edited on 23-5-2021 by BauArf56]

Fyndium - 23-5-2021 at 00:14

Considering any second hand sales of magnesium, thermite compounds etc command a significant premium, it would be hardly economical to produce it yourself by a significant margin. The large industry benefits from getting their stuff at market price.

What costs $4 per kg at market, you will pay minimum 20-50$ or even more even if you buy bulk. If you buy commercialized goods, the price can have even a second 0 before the nomination.

BauArf56 - 10-6-2021 at 02:41

PubChem on the lithium page:
Since lithium will burn in oxygen, nitrogen or carbon dioxide, and when alight it will remove the combined oxygen in sand, sodium carbonate, etc., it is difficult to extinguish once alight ... Use of normal fire extinguishers (containing water, form, carbon dioxide, halocarbons, dry powders) will either accelerate combustion or cause explosion.

Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990, p. 1312

So lithium is able to break carbonate bonds. Maybe it could react like this: Li + Na2CO3 ----> 2Li2O + Na2C2
May this work for small amounts of carbide? (obviously i'm not going to waste all my lithium in this reaction)