The region of the Capim River (Northeast of the State of Pará), due to its
large reserves of kaolin for covering paper, stands out nationally. The extraction
of the ore occurs on average at a depth of 20 meters, covered by clayey-sandy
sediments from the barrier formation, and from a level of hard kaolin, also known
as flint or semi-flint kaolin(Ferruginous), considered stable depending on the
content high iron content, which makes its application for roofing unfeasible. The
research aims to address the development of geopolymers synthesized from
waste containing aluminum silicate. Geopolymers are amorphous, threedimensional
alkalis. Aluminosilicate binder materials synthesized from alkaline
activation of clays, calcined clays, calcined kaolin, minerals, industrial waste, fly
ash and other aluminosilicates. The fly ash generated in the Bayer process
boilers under conditions of 900 °C and 120KPa was also used as a source of
aluminosilicate in the geopolymerization reaction. To increase the reactivity of the
reaction, the use of soft kaolin and flint and semi-flint(ferruginous) kaolin calcined
at different temperatures(450,550,650, 700 and 800 °C) was evaluated. And, also
at different calcination times(15,30,60 ,90 and 120 minutes). Sodium hydroxide
(NaOH, 5-30 M) and sodium silicate (Na2SiO3, SiO2/Na2O = 3.2) as alkaline
reaction medium. The residues were characterized by X-ray fluorescence (XRF),
X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR),
thermogravimetric analysis (TGA) and differential thermal analysis (DTA). And,
compressive strength tests were also carried out on the geopolymeric samples
to evaluate the degree of polymerization, since the more polymerized the
structure is, the greater the resistance. For the geopolymer based on (soft kaolin
and fly ash), the best results were obtained for the SiO2/Al2O3 ratio of 2.65 and
3.4. For the geopolymer based on (flint kaolin and fly ash) the best result was for
the SiO2/Al2O3 ratio of 2.95 and 3.57. The best results for the geopolymers based
on (ferruginous metakaolin and fly ash) were obtained with a SiO2/Al2O3 ratio of
2.88 and 3.54. The geopolymeric ceramic plate obtained showed satisfactory
performance in relation to mechanical resistance to compression and was also
synthesized with raw material that contaminates the environment, as it is
considered kaolin residue due to its high iron content.
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