FIELD OF THE INVENTION
The present invention relates to an improved method for estimation of metallic iron (Fe
met) in sponge iron applicable in steel industries.
BACKGROUND OF THE INVENTION
The process of sponge iron making aims to remove oxygen from iron ore, wherein the
departing oxygen causes micro process in the ore body making it porous. The quality of
sponge iron is primarily ascertained by the percentage of metallization (removal of
oxygen), which is the ratio of metallic iron to total iron present in the product.
Hence estimation of Fe (met) accurately is of prime importance to ascertain its quality.
The method estimation of Fe (met) is as follows:
There are two conventional method for estimation of Fe (met) which are commonly
used in industries. First one is the ferric chloride method and the second one is the
bromine methanol method.

In the first method, about 1.0 gm of sample is added to 200 ml Fe Cl3
solution and the mixture is stirred for about one hour. The mixture is then
Altered and the filtrate, is added with 400 ml of water, 25 ml of Hcl, 25 ml
of H3 PO4 and 3-4 drops of diphenyl amine sulfonate. The resulting
solution is titrated with O 1 N K2 Cr2 D7.
In the bromine methanol method, the combined iron and total iron are
estimated separately and the difference between the two is taken as the
metallic iron
OBJECTS OF THE INVENTION
It is therefore, an object of the present Invention to propose an improved
method for estimation of metallic iron in sponge iron which eliminates the
disadvantages of the prior art.
Another object of the present invention is to propose an Improved method
for estimation of metallic iron in sponge iron which is economic is use.
A further object of the present invention is to propose an improved method
for estimation of metallic Iron in sponge iron which save the time.

A still further object of the present invention is to propose an Improved
method for estimation of metallic iron in sponge iron which improves
efficiency of test result characteristic.
SUMMARY OF THE INVENTION
The present invented method of testing procedure is described as follows:
A sample of 0.5-1.0 gram of sponge iron is taken is a clean and dried
100ml measuring flask to which 3-5 gm mercuric chloride and 60-07 ml
oxygen free water are added. The contents of flask are wormed below the
boiling point for 1 hour. Thereafter the flask is cooled by covering the
mouth of the flask. The contents of the flask are then filtered through
grade 40 and 41 filter paper, the filtrate is taken in a 250 ml comical flask.
The residue is washed five times with oxygen free water and then 5-10 ml
of ortho phosphoric acid is added to it. The content of the flask Is then
titrated against standard 5/56 NKMn04 solution to obtain a faint pink at end
point. Volume of standardKMn04 consumed in ml gives metallic Iron
content is percentage on 0.5-10 gram sample bins.
To validate the above methods, the same sample has been tested by two
existing methods and the comparative results obtained are given table-1


The comperative result indicates clearly that the present invention is
capable of estimating Fe (met) content is sponge Iron with improved
performance marginally.

WE CLAIM
1. A method of estimation of metallic iron in sponge iron comprising following
steps:
- a sample of 0.5-1.0 gram of sponge iron is taken in a clean and dried 100 ml
measuring flask;
- adding 3-5 gms of mercuric chloride and 60-70 ml of oxygen free water to the
sample;
- heating the solution at 80-90°C for 1-2 hours;
- filtering the solution after cooling at ambient temperature through wattman 40
and 41 grade filter paper;
- washing the residue for 5-10 times with oxygen free water and thereafter 5 ml of
ortho-phosphoric acid is added;
- titrating the contents of the flask with standard 5/56 (N) KMnO4 solution to
obtain a faint pink at the end point;
characterized in that the volume of standard KMnO4 consumed in ml which gives
direct result of metallic iron content present in sponge iron.

The present invention relates to a method of estimation of metallic iron in sponge iron
comprising of a sample of 0.5-1.0 gram of sponge iron is taken in a clean and dried 100
ml measuring flask and adding 3-5 gms of mercuric chloride and 60-70 ml of oxygen
free water to the sample and heating the solution at 80-90°C for 1-2 hours and filtering
the solution after cooling at ambient temperature through wattman 40 and 41 grade
filter paper and washing the residue for 5-10 times with oxygen free water and
thereafter 5 ml of ortho-phosphoric acid is added and titrating the contents of the flask
with standard 5/56 (N) KMnO4 solution to obtain a faint pink at the end point
characterized in that the volume of standard KMnO4 consumed in ml which gives direct
result of metallic iron content present in sponge iron.