FIELD OF INVENTION
The present invention relates to a Simplified Inductively Coupled Plasma (ICP)
Spectrometric method for estimation of Fe (met) in sponge iron.
BACKGROUND OF THE INVENTION
The process of sponge iron making aims to remove oxygen from iron ore,
wherein the departing oxygen causes micro pores 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 the total
iron present in the product. Hence estimation of Fe(met) accurately is of prime
importance to ascertain its quality.
There are two methods which are commonly used for estimation of Fe(met). One
is the Ferric Chloride method and the other is the bromine methanol method.

In the ferric chloride method, to about 1.0 gm of the sample 200 ml of FeCI3
solution is added and the mixture stirred for one hour. The mixture is then
filtered and to the filtrate 400 ml of water, 25 ml of HCI, 25 ml of H3P04 and 3-4
drops of diphenyl amine sulfonate is added. The resulting solution is titrated with
0.1N K2Cr207.
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 ICP
Spectrometry method for estimation of Fe(met) which is an easier method than
the existing state of Arts.
Another object of the present invention is to propose an ICP Spectrometry
method for estimation of Fe(met) which is faster and less time consuming.
A further object of the present invention is to propose an ICP Spectrometric
method for estimation of Fe(met) which consumes less number of chemicals.

BRIEF DESCRIPTION OF THE INVENTION
In a 500 ml conical flask distilled water is filled half and boiled to remove
dissolved oxygen. Then 0.1-0.5 gm sample is taken in a clean and dried 100 ml
volumetric flask.
60-70 ml of oxygen free water is added and 1.0-2.0 gm mercuric chloride is
added to the flask to convert metallic iron to ferrous chloride.
Fe + HgCI2 = FeCI2 + Hg
The flask is then cooled by covering the mouth of the flask. The contents are
then filtered through grade 41 filter paper and filtrate collected into a 100 ml
volumetric flask. The residue is washed five times with oxygen free water and
then the volume is made up to 100 ml. The ICP Spectrometer is calibrated using
four synthetic standards having iron concentration of 0, 100, 500 and 800 ppm.
The calibration standards are matrix matched with the sample solution by adding
the same quantity of mercuric chloride. ,259.44 nm line is used for making the
measurements in ICP.

The method can also be used for determination of metallic iron content in iron
and steel making slag and other related materials. If the metallic Fe content is less than 10% then 0.5g of the sample is used.
To validate the above method, samples have been tested by all the three
methods and the results obtained are given below:

The close agreement between the results indicate that the method is well
capable of estimating Fe(met) content in Sponge Iron.

WE CLAIM
1. A simplified ICP Spectrometric method for estimation of Fe(met) in sponge
iron in a sample comprising the step of:
- taking 0.1-0.5 gm sample in a clean and dried volumetric flask;
- adding 60-70 ml boiled filter water and 1.0-2.0 gm mercuric chloride to
the volumetric flask containing the sample to convert metallic iron to
ferrous chloride;
- cooling the flask ;
- filtering the contents of the flask ;
- collecting the filtrate into a volumetric flask;
- washing the residue with boiled filter water at least five times, adding the
washings to the filtrate and making up the volume of the filtrate up to 100
ml;
- calibrating the ICP spectrometer using four synthetic standards having
concentration 0,100,500 and 800 ppm;
- matching the matrix of calibration standards with sample solution by
adding same quantity of mercuric chloride;
- making the measurement in ICP using 259.44 nm spectra line.

2. An ICP Spectrometric method for estimation of Fe(met) as claimed in
claim 1 which can also be used for estimation of Fe(met) in iron and steel
making slags.

ABSTRACT

TITLE; AN ICP SPECTROMETRIC METHOD FOR ESTIMATION OF
FE(MET) IN SPONGE IRON
This invention relates to a simplified ICP Spectrometric method for
estimation of Fe(met) in sponge iron in a sample comprising the step of:
- taking 0.1-0.5 gm sample in a clean and dried volumetric flask;
- adding 60-70 ml boiled filter water and 1.0-2.0 gm mercuric chloride to
the volumetric flask containing the sample to convert metallic iron to
ferrous chloride;
- cooling the flask ;
- filtering the contents of the flask ;
- collecting the filtrate into a volumetric flask;
- washing the residue with boiled filter water at least five times, adding
the washings to the filtrate and making up the volume of the filtrate up
to 100 ml;
- calibrating the ICP spectrometer using four synthetic standards having
concentration 0,100,500 and 800 ppm;
- matching the matrix of calibration standards with sample solution by
adding same quantity of mercuric chloride;
- making the measurement in ICP using 259.44 nm spectra line.