22-02-2013, 02:28 PM
DETERMINATION OF IRON IN PLAIN CARBON STEEL
Theory :
Steel is the most important commercial form of iron. It is an alloy
of iron containing 0.05 to 1.5 % carbon and traces of silicon,
manganese, sulphur, phosphorous, etc. Steel is classified into
two varieties based on composition. Plain carbon steel and alloy
steel. The main alloying element in plain carbon steel is carbon.
In addition to carbon, it may contain traces of Mn, Si, S, and P as
impurities. The major component of plain carbon steel is iron.
In the analysis of iron in the plain carbon steel, the sample is
dissolved in conc. HCl and evaporated a couple of times. This
repeated process of evaporation and leaching with conc. HCl
removes the impurities of C, S and P. The mass is finally
extracted with dil. HCl and filtered to remove silica. The filtrate
containing iron and manganese is worked out volumetrically by
titrating and aliquot quantity of the solution with a standard
KMnO4 solution.
Procedure :
1) Preparation of the sample solution :
Weigh accurately 0.5 gm of finely powdered plain carbon steel
and treat it with conc. HCl in a porcelain dish. Evaporate the
solution to dryness on a water bath. The dry mass is then
leached with small amount of conc. HCl and again evaporated.
This process of evaporation and leaching is carried out several
times, when finally the cooled mass is dissolved in about 100 ml
of dil. 2N HCl. The solution is boiled and filtered when silica is
removed as a residue and the filtrate containing iron in solution is
taken for estimation volumetrically
Result : The iron content of plain steel = __________ %
Theory :
Steel is the most important commercial form of iron. It is an alloy
of iron containing 0.05 to 1.5 % carbon and traces of silicon,
manganese, sulphur, phosphorous, etc. Steel is classified into
two varieties based on composition. Plain carbon steel and alloy
steel. The main alloying element in plain carbon steel is carbon.
In addition to carbon, it may contain traces of Mn, Si, S, and P as
impurities. The major component of plain carbon steel is iron.
In the analysis of iron in the plain carbon steel, the sample is
dissolved in conc. HCl and evaporated a couple of times. This
repeated process of evaporation and leaching with conc. HCl
removes the impurities of C, S and P. The mass is finally
extracted with dil. HCl and filtered to remove silica. The filtrate
containing iron and manganese is worked out volumetrically by
titrating and aliquot quantity of the solution with a standard
KMnO4 solution.
Procedure :
1) Preparation of the sample solution :
Weigh accurately 0.5 gm of finely powdered plain carbon steel
and treat it with conc. HCl in a porcelain dish. Evaporate the
solution to dryness on a water bath. The dry mass is then
leached with small amount of conc. HCl and again evaporated.
This process of evaporation and leaching is carried out several
times, when finally the cooled mass is dissolved in about 100 ml
of dil. 2N HCl. The solution is boiled and filtered when silica is
removed as a residue and the filtrate containing iron in solution is
taken for estimation volumetrically
Result : The iron content of plain steel = __________ %