# Is it possible to make metal fulminates?

Is it possible to make fulminates such as: magnesium fulminate, copper fulminate, etc. by the metal + $\ce{HNO3}$ + $\ce{EtOH}$ reaction?

• Welcome to chemistry.se! If you have questions about how to beautify your posts, have a look at the help center. Do you want to know more about this site, please take the tour. At least copper fulminate seems to be straight forward. – Martin - マーチン Jan 20 '15 at 5:47
• the wikipedia article on potassium fulminate mentions preparation by reacktion of potassium amalgam with mercury fulminate, which is slightly soluble. I'm pretty sure, other metals that can reduce mercury should work as well. However, it MUST be noted, that synthesis with slightly soluble explosive salt may take months, as stirring is obviously not an option. – permeakra Jan 20 '15 at 10:07

In The Preparatory Manual of Explosives (paperback at amazon), the author, Jared Ledgard, provides a procedure for the preparation of copper fulminate that can be summarized as follows:

To 100 mL of 70% $\ce{HNO3}$, 30 g of anhydrous $\ce{Cu(NO3)2}$ is added under stirring. If the copper nitrate doesn't dissolve properly, add water dropwise until it does. (NOTE: Adding water to concentrated acids usually isn't the best idea!) The solution is stirred for 24 hrs at room temperature and then heated to roughly 80 °C. Under stirring, 120 g of 95% ethanol are added. After addition of the ethanol, the heat source is removed and the mixture is alllowed to reach room temperature. The precipitate is rapidly filtered off, washed with several hundred mL od cold water and dried in a desiccator over magnesium sulfate. The product, copper fulminate, should be stored in a desiccator over sodium sulfate in a refrigerator.

NOTE

1. To my opinion, the procedure leaves out significant information, such as the exact temperature of the aqueous solution while adding the ethanol. It is not clear whether and how much ethanol is supposed to evaporate. While the author suggests to carry out the reaction in a beaker, a setup with a two-neck flask, reflux condenser and a dropping funnel might be a better idea.

2. Handling fairly concentrated nitric acid requires safety precautions: A fume hood, eye protection, gloves and a lab coat are mandatory!

3. The reaction product is a primary explosive! While less shock sensitive than mercury fulminate, it still will go off on impact (or upon heating above ~200 °C).

In the case of these or similar sensitive materials, there is a good rule of thumb: If you have to ask on a Q&A site - Don't touch it!

• The best part of it is I think the insane amounts they use, absolutely "blown" out of proportion. (+1) for the safety advice. – Martin - マーチン Jan 20 '15 at 9:41
• @Martin the manual is NOT for academic science, it is for applied chemistry, when you need a lot of staff. Basically, it offer mostly upscaled procedures, usable to produce a large loads of staff. For example, a kilo or so of priming mixture for capsules, a good firework and so on. Some procedures mentioned in the book operates literally kilos of reagents (and litres of solvents) – permeakra Jan 20 '15 at 10:03
• @Martin And yes, it does contain a procedure involving close to kilo of mercury fulminate as a raw material. – permeakra Jan 20 '15 at 10:08