How can I effectively dry out Iron Chloride?

In summary, the solution of iron chloride is very hygroscopic, making it difficult to evaporate the water off. Evaporation of the water only leads to the formation of a "muddy" substance. Another way to de-hydrate the substance is to heat it, but this is not possible because it is in a plastic container. The final way to de-hydrate the substance is by using azotropic distillation.
  • #1
mrjeffy321
Science Advisor
877
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I have/had a solution of Iron (III) Chloride. I wanted to extract the Iron Chloride out of solution, so I decided to evaporate all the water off and just collect the crystals that form, right? Wrong, appearently, it is very hygroscopic making it some what difficult to actually dry it. I have gotten it to a thick, dark brown, "muddy" lucking substance, but it won't dry any further. I am attempting to evaportate off the water in the hot summer sun, but after about a week at this same stage, it hasnt changed.

Is there another way of de-hydrating, this substance that seems to just love water?

I can't really heat it very much (using an oven or flame) because, for one, I have it in a plastic container because Iron Chloride acts like an acid on metals, so I don't want to melt the container, and two, I think that the Iron Chloride melts and deomposes at a very low temperature, so I don't want to alter the substance either.

I suppose, in theory, if I could put it in a container that is air tight, the lower the pressure sugnificantly, I could lower the boiling point of water and pump the steam out. But this is a little to much in the way of building something than I had intended. Is there an easy chemical way?
Once I get it dried out, all I need to do is make sure I keep it in a sealed container, so as not to let any more water get to it.
 
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  • #2
It will decompose to a basic iron chloride, or even ferric hydroxide. It's tough to get ride of the water with just heating.

I'm not sure if pulling a vacuum on it will do the job either, worth a try I suppose.

Normally anhydrous ferric chloride is made by passing chlorine over hot iron, the FeCl3 drops out of the vapour state downstream as the gases cool.

You can heat it in a stream of HCl gas, or mix it with several times its volume of ammonium chloride and then heat the mixture to drive off water and excess NH4Cl. The ammonium chloride functions as a local source of HCl.

You _might_ be able to do it by using azotropic distallation. Drop the FeCl3 into some alcohol, ethanol or isopropanol will do, and add some heptane or toluene. Then slowly distill off the water-alcohol-hydrocarbon azeotrope, the alcohol replacing the water as a complexing agent with the FeCl3. Once all the water is removed, the alcohol and hydrocarbon can be distilled off until the FeCl3 starts to crystallize out. Again, I can't 100% promise that will work.

One more route would be to add more HCl and then extract the FeCl3 from the water using ether, and remove the organic solvent.

All of those mean using glassware, plastic isn't going to cut it.

Hmm, also see:
http://www.answers.com/topic/ferric-chloride
 
  • #3


One option for effectively drying out Iron Chloride is to use a desiccant, such as silica gel or calcium chloride. These substances are able to absorb moisture from the air and can help to dry out your Iron Chloride. Simply place the desiccant in a sealed container with your Iron Chloride and let it sit for a few days, checking periodically until it is completely dry.

Another option is to use a vacuum oven. This involves placing your Iron Chloride in a heat-resistant container and placing it in a vacuum oven, which removes the air and lowers the pressure, causing the water to evaporate at a lower temperature. This method may require specialized equipment, but it can be more effective than simply using heat.

You could also try using a heat gun or hair dryer on a low setting to gently warm and dry out the Iron Chloride. Be sure to use caution and monitor the temperature to avoid melting the plastic container or causing the Iron Chloride to decompose.

If all else fails, you could try contacting a chemical supply company or laboratory for advice on how to effectively dry out Iron Chloride. They may have specialized equipment or techniques that can help you achieve your goal.
 

1. What is Iron Chloride and why does it need to be dried?

Iron Chloride, also known as ferric chloride, is a chemical compound made up of iron and chlorine atoms. It is commonly used as a coagulant in water treatment and for etching copper in the production of circuit boards. It needs to be dried for various reasons, such as preserving its chemical stability and preventing clumping or caking.

2. How is Iron Chloride typically dried?

Iron Chloride can be dried through several methods, including air drying, oven drying, or using a desiccant such as silica gel. The most common method is air drying, where the compound is left to sit in a well-ventilated area until all moisture has evaporated. Oven drying can also be used, but it requires careful monitoring of temperature to prevent the compound from decomposing. Using a desiccant is the most efficient method, as it absorbs moisture quickly and effectively.

3. What are the potential risks of not properly drying Iron Chloride?

If Iron Chloride is not properly dried, it can lead to the formation of iron oxychloride, which can cause the compound to become unstable and potentially hazardous. This can result in a loss of its coagulation properties, making it ineffective in water treatment processes. Additionally, the presence of moisture can also cause the compound to clump or cake, making it difficult to use in industrial applications.

4. How can the drying process be expedited?

The drying process can be expedited by increasing the surface area of the Iron Chloride. This can be achieved by breaking up large lumps or using a fine powder instead of larger granules. Additionally, using a desiccant or applying gentle heat can also speed up the process.

5. Are there any safety precautions to take when drying Iron Chloride?

Yes, there are some safety precautions to consider when drying Iron Chloride. It is important to wear protective gear, such as gloves and a mask, to avoid direct contact with the compound. If using an oven, make sure to carefully monitor the temperature to prevent overheating and the formation of toxic fumes. It is also important to handle the compound in a well-ventilated area to avoid inhaling any dust particles.

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