Characterization Physics, Chemistry and Mineralogy of Waste from Kaolin and their Potential Pozzolanic to Alkali Activation

Abstract

The University Federal of Paraíba has developed various researches to explore the potential for recycling of industrial waste of Paraíba. Among them, the potential of use in the waste generated by processing of kaolin, which is one of the activities of great economic importance to the State of Paraíba and municipalities producers, because it causes a great environmental impact due to lack of an established recycling process. The kaolin processing generates large amounts of waste, one of fractions, a sandy (called in this study of RGC) containing quartz, mica and calcite; and other clay (called in this study of RFC) containing higher amounts of kaolinite. This objective of study is the characterization physical, chemical and mineralogical of waste kaolin (RFC and RGC) in order to evaluate the potential use of these wastes in the alkaline activation using silicates sodium and potassium. The characterizations physics, chemistry and mineralogy were by XRF, XRD, Unit Mass, Specific Mass and Specific Area. With the objective of studying the potential of waste as a material pozzolanic, it was processing through grinding at 10.000, 20.000, 40.000, 60.000 and 80.000 rpm and with the purpose of evaluating the reactivity of materials, these wastes were calcined at 750°C/2h.The wastes RFC and RGC had different properties according to the processing. Thus, the waste RFChas the potential pozzolanic to use in alkaline activation.

Alkaline Activation of Aluminum and Iron Rich Precursors

“…The main geopolymers precursors used are fly ash and blast furnace slag but also metakaolin. However, other materials such as kaolin waste, red brick waste and weathered soils have not been systematically investigated with regard to development of matrices geopolymerics [10][11][12], possibly because such precursors often contain much lower amounts of aluminium and very high amounts of iron oxide when compared to the main precursors. This paper aims to access the potential use of iron rich sources as precursors for alkaline activation.…”

Reuse of Waste from the South West of England in Alkali-Activated Cement Concrete

“…A previous paper of this project [11], looking at the performance of the waste in AAC mortar, showed that the increase of the water demand was the main reason for the reduction in the compressive strength of the test mortars using mica and china clay sand. Other authors have looked at the kaolin waste from Brazil with a focus on altering the leftover kaolinite to metakaolin to use it as binder [12][13][14]. However, that cannot apply to the waste of the UK china clay production, as it does not contain high amounts of left-over kaolinite as present in the waste from Brazil.…”