Uses for Ferric chloride
Ferric Chloride forms a corrosive solution which is used as a coagulant in sewage and wastewater treatment and drinking water production. It is used to remove suspended solids and particulate matter from water. As a flocculant it has the function of precipitating heavy metals and sulfides, bleaching, deodorization, degreasing, sterilizing, dephosphorizing and decreasing the COD & BOD of effluent water.
It is commonly used as an etchant for copper-based metals in printed circuit boards. Iron(III) chloride etches copper in a two-step redox reaction to copper(I) chloride and then to copper(II) chloride in the production of printed circuit boards. "Click Here" for instructions on how to make up etching solution using solid ferric chloride.
See below for How to etch copper with Ferric chloride
See below for Neutralising Ferric Chloride Solution
For further information on using Citric acid as a catalyst with ferric chloride for copper and brass in the Edinburgh Etch "Click Here"
Other uses include:
Ferric chloride In the laboratory
iron(III) chloride is commonly employed as a Lewis acid for catalysing reactions such as chlorination of aromatic compounds and Friedel-Crafts reaction of aromatics. It forms adducts with Lewis bases such as triphenylphosphine oxide, e.g. FeCl3(OPPh3)2.
Iron(III) chloride is a mild oxidising agent, for example, it is capable of oxidising copper(I) chloride to copper(II) chloride.
When heated with iron(III) oxide at 350C, iron(III) chloride gives iron oxychloride.
Reducing agents such as hydrazine convert iron(III) chloride to complexes of iron(II).
Reacts with cyclopentadienyl magnesium bromide in one preparation of ferrocene, a metal-sandwich complex.
Used in conjunction with NaI in acetonitrile to mildly reduce organic azides to primary amines.
It is used to produce Weigerts iron hematoxylin solution for nuclear stains and trichrome staining.
Other uses include:
Staining blades of swords and knives. Etching the widmanstatten pattern in iron meteorites. For the etching of photogravure plates for printing photographic and fine art images in intaglio and for etching rotogravure cylinders used in the printing industry and for making printed circuit boards(PCBs) Used in veterinary practice to treat overcropping of an animal's claws Reacts with cyclopentadienylmagnesium bromide in one preparation of ferrocene, a metal-sandwich complex. Sometimes used in the technique of Raku firing as an additive during the reduction process, turning a pottery piece a burnt orange color due to the iron content present in the reducing atmosphere. Used to test the pitting and crevice corrosion resistance of stainless steels and other alloys. Used in conjunction with NaI in acetonitrile to mildly reduce organic azides to primary amines.
How to etch copper with Ferric chloride
This solution is a ready to use strength of ferric chloride and do not require further diluting with water. Immerse prepared copper board in ferric chloride solution. Using tapes adhered to the back will help to place the plate in solution so that it is not resting on base of tank. Agitate until etching has been completed. Etching process can be accelerated by heating solution up to a maximum of 55°C. When removing plate from tank allow resiual solution to drain back into tank. Rinse thoroughly with clean water. Check if the etch is as desired and if not retun plate into the solution and repeat the process.
A fresh bath of ferric chloride will be a red / brown colour and with use it will change to a muddy brown colour as more and more copper is dissolved. Eventually the solution will turn almost black indicating that the solution is exhausted.
Neutralising Ferric Chloride Solution:
Ferric chloride solution can be neutralised with Soda ash / sodium carbonate. The ferric chloride solution and the sodium carbonate should be mixed together on a 1:1 ratio (i.e. 1kg sodium carbonate will neutralise 1L of ferric chloride solution). Neutralisation will produce gasses so it is important to carry out the procedure in a well ventilated area and wear all necessary safety protective gear. After 10 to 15 minutes a solid precipitate should form and this can then be disposed of.
PLEASE NOTE: This product is not for human or animal consumption.
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