Utilisation of wood ash from biomass for the production of ceramic products

Abstract

Utilisation of biomass as fuel is very attractive from the ecological point of view. Such way of energy extraction is ecologically clean (zero CO2 emission) and biomass is renewable and theoretically inexhaustible local energy source. However, during the utilisation of secondary raw materials of biomass for energy production, higher amount of ash accumulates. Wood ash analysed in the research consists of two types of particles: first type – nonflammable mineral particles consisting of the following main elements: Si, Ca, Fe, O and C (86%) and the main elements of the particles of second type are C and O (98%). The aim of the research is to analyse the possibility to utilise wood ash from biomass for the production of ceramic products. Formation masses are prepared by incorporating from 5% to 60% of wood ash additive and burned at various temperatures. It is identified that this additive influences the properties of ceramic body, i.e. reduces drying and burning shrinkage, density, compressive strength, thermal conductivity, increases water absorption and porosity. Additive of wood ash from biomass influences the ceramic body as a natural pigment that brightens the ceramic body. Colour change is determined by sufficient amounts of calcium pyroxene in the composition thereof iron is inserted.