Ferric Chloride 2

Ferric Chloride

Ferric chlorideFerric Chloride is effective primary coagulants based on trivalent iron (Fe3+), excellent for drinking water production, wastewater treatment applications such as phosphorus removal, struvite control and sludge conditioning. The products also control the formation of hydrogen sulfide and prevent the formation of odour and corrosion.

Iron(III) chloride, also called ferric chloride, is an industrial scale commodity chemical compound, with the formula FeCl3and with iron in the +3 oxidation state. The colour of iron(III) chloride crystals depends on the viewing angle: by reflected light, the crystals appear dark green, but by the transmitted light they appear purple-red. Anhydrous iron(III) chloride is deliquescent, forming hydrated hydrogen chloride mists in moist air. It is rarely observed in its natural form, the mineral molysite, known mainly from some fumaroles.

When dissolved in water, iron(III) chloride undergoes hydrolysis and gives off heat in an exothermic reaction. The resulting brown, acidic, and corrosive solution is used as a flocculant in sewage treatment and drinking water production, and as an etchant for copper-based metals in printed circuit boards. Anhydrous iron(III) chloride is a fairly strong Lewis acid, and it is used as a catalyst in organic synthesis.

Why is ferric chloride base?

Simply, except in the presence of free oxygen, copper will not react to any significant extent with hydrochloric acid which is the acid produced with ferric chloride solutions. When ferric chloride is dissolved in water the solution becomes strongly acidic as a result of hydrolysis.


ferric chloride Why is ferric chloride used in water treatment?

Ferric chloride is the coagulant of choice for many industrial and sanitary wastewater treatment applications, due to its high efficiency, effectiveness in clarification, and utility as a sludge dewatering agent. The chemical leaves a slight residual colour and offers very good turbidity removal.

What neutralises ferric chloride?

The solution must not be put down the drain because of residual copper ions left in it. To make it safe for disposal, you can add sodium carbonate (washing soda) or sodium hydroxide to it to neutralise it, until the pH value goes up to between 7.0 and 8.0, testing it with indicator paper.

Are Iron based coagulants hazardous?

CHEMICAL DANGERS: The substance decomposes on heating above 200°C producing toxic and corrosive gases including chlorine and hydrogen chloride. The substance decomposes on contact with water producing hydrogen chloride. The solution in water is a medium strong acid.

What is the use of Ferrous chloride?

It is used in sewage treatment, in the dying of fabrics, and for many other uses. Ferrous chloride solution is the greenish-white crystalline solid dissolved in water. It is corrosive to metals and tissue. It is used in dyeing, in medicine, and sewage treatment.


Iron(III) chloride is used in sewage treatment and drinking water production. In this application, FeCl3 in slightly basic water reacts with the hydroxide ion to form a floc of iron(III) hydroxide, or more precisely formulated as FeO(OH), that can remove suspended materials.

[Fe(H2O)6]3+ + 4 HO → [Fe(H2O)2(HO)4] + 4 H2O → [Fe(H2O)O(HO)2] + 6 H2O

It is also used as a leaching agent in chloride hydrometallurgy, for example in the production of Si from FeSi (Silgrain process).

Another important application of iron(III) chloride is etching copper in a two-step redox reaction to copper(I) chloride and then to copper(II) chloride in the production of printed circuit boards.

FeCl3 + Cu → FeCl2 + CuCl
FeCl3 + CuCl → FeCl2 + CuCl2

Iron(III) chloride is used as a catalyst for the reaction of ethylene with chlorine, forming ethylene dichloride (1,2-dichloroethane), an important commodity chemical, which is mainly used for the industrial production of vinyl chloride, the monomer for making PVC.

H2C=CH2 + Cl2 → ClCH2CH2Cl

Other Uses

  • Used in anhydrous form as a drying reagent in certain reactions.
  • Used to detect the presence of phenol compounds in organic synthesis; e.g., examining the purity of synthesised Aspirin.
  • Used in water and wastewater treatment to precipitate phosphate as iron(III) phosphate.
  • Used by American coin collectors to identify the dates of Buffalo nickels that are so badly worn that the date is no longer visible.
  • Used by bladesmiths and artisans in pattern welding to etch the metal, giving it a contrasting effect, to view metal layering or imperfections.
  • Used to etch the widmanstatten pattern in iron meteorites.
  • Necessary 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.
  • Used to make printed circuit boards (PCBs).
  • Used in veterinary practice to treat overcropping of an animal’s claws, particularly when the overcropping results in bleeding.
  • Reacts with cyclopentadienyl magnesium bromide in one preparation of ferrocene, a metal-sandwich complex.
  • Sometimes used in a technique of Raku ware firing, the iron colouring a pottery piece shades of pink, brown, and orange.
  • 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.
  • Used in an animal thrombosis model.
  • Used in energy storage systems
  • Historically it was used to make direct positive blueprints.
  • A component of modified Carnoy’s solution used for surgical treatment of keratocystic odontogenic tumour (KOT)

Is It Corrosive?

Ferric chloride solution is colourless to light brown aqueous solution that has a faint hydrochloric acid odour. Highly corrosive to most metals and probably corrosive to tissue. Noncombustible. Used in sewage treatment and water purification.

ferric chlorideWhere can I buy Ferric Chloride?

You can buy it directly from us, just send us a message at bottom of this page or give us a call.
We are a UK company based in Kent and are able to supply you with your wastewater treatment chemicals.
Ferric Chloride MSD Sheets – GPC Ferric Chloride Solution

What is the use of flocculant?

Flocculants, or flocculating agents (also known as flocking agents), are chemicals that promote flocculation by causing colloids and other suspended particles in liquids to aggregate, forming a floc. Flocculants are used in water treatment processes to improve the sedimentation or filterability of small particles.
Read more about flocculants here

Chemical Economics Handbook

In industrialized regions (United States, Western Europe, and Japan), ferric chloride markets are relatively mature. Although it is recognized as a highly effective flocculant and sequestering agent for sludge and odour control, substitution from competing products will lead to relatively flat demand growth.

In Asia and the Middle East, where economic and population expansion has drawn greater demand for water management, ferric chloride continues to experience above-average growth.

For countries in Central and Eastern Europe, which have mostly completed compliance with new regulations, or many countries in Latin America, which are slow to invest in infrastructure or adopt necessary environmental and health legislation, growth is likely to be slower. As a result, global demand is forecast to increase by only about 1% per year through 2021.

Consumption in the United States is forecast to grow at 1.3% annually during 2016-21. Ferric chloride producers tend to have a regional, rather than a national outlook because transportation costs are significant. More than 80% of all ferric chloride is sold in municipal bids, with 53% sold for municipal wastewater applications, and 37% for potable water treatment applications.

Industrial water treatment applications account for 6% of consumption, with the remaining 5% sold in non-waterbased treatment applications, such as electronic and photographic etchants, metal surface treatment, and as a catalyst. Much of the etchant activity has moved to Asia. Electronic applications, especially for PCBs, are small in the United States.

In Western Europe, ferric chloride is used mostly as a coagulant for sewage treatment and potable water production. It is also used as an etchant for copper-based metals in printed circuit boards, a precursor in synthetic iron oxide and speciality pigment production, and in the pharmaceutical industry, where it is used as a precursor for iron-bearing medicine for anaemia treatment.

Growth in Western Europe is stable, with all countries having installations in place to comply with EU legislation for clean water standards in both the municipal and industrial sectors. In the forecast period, consumption is expected to stagnate, with a largely mature water treatment market. No new uses for ferric chloride are on the horizon.

Water treatment will continue to be the largest end use for ferric chloride in China, accounting for about 69% of the total consumption in 2016. Wastewater is treated and recycled extensively for industry use and farm irrigation.

Although industry wastewater discharge has been decreasing in recent years, the discharge of domestic sewage has been growing rapidly. Therefore, as a very economic wastewater treatment agent, ferric chloride in this end use is expected to increase moderately at an average annual rate of 2.9% during 2016-21.

This excerpt is taken from the chemical economics handbook* – https://ihsmarkit.com/products/ferric-chloride-chemical-economics-handbook.html


ferric chloride warning

Iron(III) chloride is harmful, highly corrosive and acidic. The anhydrous material is a powerful dehydrating agent.

Although reports of poisoning in humans are rare, ingestion of ferric chloride can result in serious morbidity and mortality. Inappropriate labelling and storage lead to accidental swallowing or misdiagnosis. Early diagnosis is important, especially in seriously poisoned patients.


Ferric Chloride 4

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Removal of Suspended Solids and COD
You coagulate and flocculate effluent to remove the suspended solids from wastewater at the end of a manufacturing process.

The coagulant changes the electrical charge of the suspended solids so they start to attract each other to form small particles. Flocculation brings these small particles together to form flocs, using mechanical processes (eg DAF) these flocs can be made to either rise or fall to allow them to be removed from the wastewater.

Once these suspended solids and the COD values associated with them are removed, the clean effluent can then be let to sewer, potentially saving your company thousands of pounds annually in trade effluent charges.

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