Investigation Of Matisaa Gray Rock As A Potential Raw Material For The Manufacture Of Cement

ABSTRACT

Owing to the depletion rates of coastal limestone, the characterization of cementitious

materials occurring on the dry land is important in order to assess their potential as alternative

materials for the manufacture of cement. In this study, a naturally occurring

terrestrial rock herein referred to as “Matisaa gray rock” has been studied to determine

its potential for the manufacture of cement. Matisaa gray rock is found in Matisaa village,

Kitui County, Kenya, and it covers an approximate area of 7 acres.

These cementitious properties were studied using X-ray fluorescence, X-ray diffraction,

vibrational spectroscopy, scanning electron microscopy, micro-sieve, and Blaine

techniques. Matisaa gray rock was found to contain all the oxides of cement in the following

percentage abundances: 39.03 – 42.73 wt.% for CaO, 15.68 – 16.79 wt.% for

SiO2, 0.47 – 4.81 wt.% for Al2O3, 0.55 – 1.04 wt.% for Fe2O3, 1.56 – 3.56 wt.% for

MgO, 3.30 – 6.06 wt.% for SO3, 0.11 – 0.21 wt.% for Na2O, and 0.59 – 2.64 wt.% for

K2O. Except for SO3, the proportions of the remaining oxides were found to be within

the recommended thresholds.

The minerals that dominate Matisaa gray rock are dolomite (CaMg[CO3]2) and kutnohorite

(Ca[Mn2+;Mg; Fe2+][CO3]2) with trace mineral phases of quartz (SiO2) and

periclase (MgO). The morphology of Matisaa gray rock powder comprises of irregularly

shaped particles that are compact with rough superficial texture. 69.65% of the

particle size composition of Matisaa gray rock was found to be