Activation Alkaline Waste Kaolin for Fabrication of Building Blocks

Abstract

In the state of Paraíba, one of the activities of great economic importance is that of the kaolin processing industry. This type of processing generates large amounts of waste that are displayed randomly in the environment, which has attracted attention, because the environmental impact caused by it and the lack of established process of recycling. The University Federal o Paraíba has been developing several research to explore the potential for recycling of industrial waste from Paraíba, mainly waste of kaolin. This research have pointed to the feasibility of using waste as aggregate and pozzolan in the development of mortars use multiple. These wastes have different size fractions, depending on the stage of processing: a sandy (termed in this study of RGC) containing mainly quartz, mica and calcite; and other clay (termed in this study of RFC) is thinner, containing higher amounts of kaolinite. This study aims to evaluate the potential of alkaline activation from waste kaolin (RGC and RFC) by comparing the activation using sodium silicate and hidroxide of calcium. With the objective of studying the potential of waste as a material pozzolanic, it was processing through grinding at 80.000, 60.000, 40.000, 20.000 and 10.000 rotations and with the purpose of evaluating the reactivity of materials, these wastes were calcined at 750°C/2h. For the mechanical characterization was using an equipment universal testing of Shimadzu Servopulser, where it was observed that only RFC, when calcined, developed strength in both activations, and the activated with silicate sodium with higher strength. The RGC, both in the state in natura and calcined did not show satisfactory mechanical strength to the test under the conditions of synthesis used in this research. Thus, the waste RFC's studied in this work has the potential to be used as constituent materials for building blocks in terms of its mechanical properties.

Estudio cristalográfico, reactividad térmica y caracterización de residuos Silicoaluminatos feldespáticos.

“…Universidad Autónoma del Estado de Hidalgo ISSN: 2395-8405 pág. 30 con silicato de sodio e hidróxido de calcio, ha sido empleado por Gómez et al, para la fabricación de block de construcción [13]. Con las arenas de caolín se han logrado producir cerámicos con alta resistencia térmica, gracias a sus propiedades puzolánicas se ha empleado para la elaboración de cementos [14,15].…”

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.…”