Pyroxinite is naturally occurring Magnesium Silicate mineral. It is an ultrabasic igneous rock consisting essentially of minerals of the Pyroxene group. The types of Pyroxene and the ore minerals present in the rock form the basis for determination of the variety of Pyroxinite. Pyroxinites are mainly composed of SiO2 and MgO whereas Cr2O3, CaO, Al2O3, Fe2O3 etc are present as minor constituents.

Pyroxinites are used as flux in Iron and Steel industry as well as Ferro-Alloy Plants. Pyroxinite helps to condition the slag as well as to control the basicity. Main benefits of Pyroxinite over Dolomite in slag conditioning are: higher MgO content, reduced energy consumption, lower coke consumption, reduced slag vilume and lower CO2 emissions.

Analysis of Pyroxinite by Classical method is time consuming. Attempts have been made in order to achieve a rapid method to evaluate parameters like Al, Ca, Mg, Cr, Fe of Pyroxinite by dissolving the sample with the help of Microwave Digester and analyzing the Microwave Digested solution by ICP-OES. One inhouse standard sample of Pyroxinite was analyzed in duplicate and the calibration was made with ICP multi element standard (100mg/litre)

Details of Microwave Digestion:

Sample wt = 0.200 gm;

Temp.          = IR 230 0C

Pressure     = 40 bar

Reagents used:
HCl       = 2 ml
HNO= 6 ml
HF        = 3 cc
H2O2 = 1 cc
Parameters Classical results (%) Obtained results by ICP (%)
(1) (2)
Al2O3 3.20 3.12 3.14
Cr2O3 0.38 0.34 0.30
Fe2O3 9.63 9.54 9.71
CaO 1.83 1.89 1.79
MgO 31.20 31.33 30.68

Analysis Spectra

Analysis Spectra 1

Contributed by: Mr. Kajal Roy (under guidance of Prof. Barun Gupta)