Caracterização tecnológica e radiométrica de um diabásio da região de Apuiarés - CE

• Ano de defesa: 2011
• Autor(a) principal: Silva, Francisco Diones Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Geologia; Rochas ornamentais; Caracterização radiométrica; Radônio; Diabásio; Petrologia; Rochas - Testes
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/1425

This paper presents the technological and mineralogical characteristics of a diabase, which outcrop in the form of dike is located in the district Canafístula in Apuiarés - CE. In order to assess their qualities for application as ornamental, were carried out technological tests of fitness levels and physical-mechanical, based on standards from ABNT, as well as radiometric measurements of the amount of uranium, thorium and radioactive potassium in the rock, beyond radon exhalation rate. The radiometric measurements were performed using the methods of gamma spectrometry and detection of active exhalation of radon gas to monitor the amount of 222Rn. Added to the main objectives of this study were also made petrographic directed to the recognition of the mineralogical composition and textural features among other features. The petrographic analysis allowed to classify the rock as olivine diabase, porphyritic texture, composed of mineralogically titanaugita olivine + plagioclase + + + apatite ± opaque ± iddingsita clorofeíta ± biotite. This has lithotype ranging gray to black, with isotropic structure. The degree of microcracking of the rock is located around 3.53 / mm ², where 97.9% of the cracks are of the type intragrão and 2.1% are of the intergrain. The physical indices showed higher than average for siliciclastic rocks in Brazil, namely, apparent specific gravity, porosity and water absorption with respectively 3113 kg / m³, 0.17% and 0.06%. The values of uniaxial compressive strength also exceed the average for Brazilian siliciclastic rocks and also within the limits of ASTM, with an excellent compressive strength of 192 MPa. Regarding the 3-point bending test, the rock exhibited value of 20.4 MPa, well above the average for Brazilian siliciclastic rocks and ASTM. The behavior of the samples when subjected to wear AMSLER, gave a performance with 0.66 mm wear for a journey of 1000m below the average for Brazilian siliciclastic rocks. The analysis by gamma spectrometry provided values for 238U and 40K, of 0.54 ppm and 2.88%, and when transformed into Bq.kg-1, corresponded to 6.8 and 48.3, respectively. The final activity of radon emanation (CRN) and radon exhalation rate (E) registered a content of <0.016 Bq.kg-1 (<0.432 pCi.kg-1) and <0.002 Bq.m-2h-1 (<0.054 pCi.m-2.h-1).Within this context, the olivine diabase porphyry shown to have diverse applications such as ornamental material for optimal mechanical characteristics and low concentrations of radioactive elements as well as low emanation and exhalation of 222Rn, that due to its material characteristics of basic composition, good mechanical strength, low porosity and low amount of microcracking