"Aplicação da difração e flourescência de raios-X (WDXRF): ensaios de argilominerais"

Abstract

Clay minerals are structural elements of soil applied in agreement with its properties. The characterization of this material has been necessary for technological, environmental, ecological and legal factors. In this scope to make possible a fast methodology, safe and efficient is especially important. In this work two procedures are described, the first to identify the clay minerals found in loamy soils by x-ray diffraction and the second determine quantitative constituent macro and micro of the clay by x-ray fluorescence (WDXRF), applied the fundamental parameters method, that, it doesn't use calibration curves. Those procedures were applied in five soil samples given by a company of little, located in Ipube, Pe. The results by x-ray diffraction showed the predominance of the clays minerals kaolinite and illite, the ones which, they were confirmed by means of the quantitative analyses of the majority elements by x-ray fluorescence. The results for the minority elements they were compared with the values reference for soil published by CETESB.

Mineralogical characterization of natural clays from Brazilian Southeast region for industrial applications

“…The XRD patterns of heated samples did not show the characteristic peaks of kaolinite (dioctahedral). This result verified the presence of kaolinite in both clays [44]. The results obtained in this work for both clay samples showed that the dominant clay minerals were illite and kaolinite.…”

“…4b), illite was identified by the presence of peaks (001) at 10.29 Å and (002) at 4.98 Å while kaolinite was detected by the peaks (001) at 7.16 Å and (002) at 3.58 Å. The illite peak (003) at 3.3 Å was overlapped by the quartz peak at 3.35 Å. Quartz peak (001) was not present [44]. The XRD patterns of glycolated samples showed small variations in the position of the illite peak (001) of Taubaté clay, whereas that peak of Tremembé clay remained at 10.29 Å.…”

Using the mineralogy of river sediments as pollution indicator of clay mining activity

“…This procedure is performed to assist the clay minerals identification. The ethylene glycol treatment is used to identify expansible minerals, allowing distinguish the smectite group minerals, while the heat treatment promotes the disappearance of the kaolinite, smectite and gibbsite peaks due to loss of the mineral crystalline structure that becomes amorphous to X-rays (SCAPIN, 2003).…”

Aplicação da quimiometria para caracterização química de combustíveis tipo MTR por fluorescência de raios X

“…Assim, interpolando-se nessa curva a cps do elemento de uma amostra desconhecida, determina-se a sua concentração (Pimentel et al, 1996;Souza 2007 espessura infinita e tem uma superfície razoavelmente plana (Lachance et al, 1995;Scapin, 2003). Na etapa da previsão é necessário estimar primeiramente uma composição aproximada da amostra.…”

“…O método de parâmetros fundamentais (FP) utiliza algoritmos que permitem calcular a composição química de uma amostra, sem a utilização de padrões similares, a partir da medida da intensidade da linha de emissão do analito e dos valores tabelados dos principais parâmetros fundamentais, como distribuição espectral primária (fonte), coeficiente de absorção (fotoelétrico e de massa), rendimento de fluorescência e outros (Bertin, 1970;Lachance et al, 1995;Nagata et al, 2001;Scapin, 2003;Scapin, 2008).…”