Use of Ash from the Incineration of Elephant Grass (<i>Pennisetum purpureums shaum</i>) into Clayey Ceramic

Abstract

Ashes generated in industrial processes are usually discarded and contribute to environmental pollution. Large scale incorporation into clayey ceramic products for civil construction, such as bricks and tiles, could be a permanent solution. Based on this rationale, this works has as its objective to characterize an ash waste from the incineration of elephant grass and to evaluate its incorporation into a clay to produce red ceramic. The waste was submitted to mineralogical and chemical characterization. Compositions were prepared with incorporation of the waste in amounts of up to 20 wt.% into the clay. Specimens were prepared by extrusion and fired in a laboratory furnace at 850°C. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural strength. The results showed that the waste is mainly composed of quartz and calcium compounds that sensibly reduce the linear shrinkage and does not change the other properties of the ceramic.

Assessing technological properties and environmental impact of fired bricks made by partially adding bottom ash from an industrial approach

“…At this point, discrepancies among researchers can be highlighted. While Sutcu et al [15] and Silva et al [34] reported similar increasing rates or both apparent porosity and water absorption, in the case o 20 wt% o BBA replacement (between 6 and 8%), Eliche-Quesada and Leite-Costa [28] showed higher values or the same replacement percentages (more than 100% in the case o water absorption and 40% in the case o apparent porosity). The dierence may be based on the particle size distribution o added ashes.…”

Influence of Firing Temperature on the Behavior of Clay Ceramics Incorporated with Elephant Grass Ash

“…Table 1 presents the chemical composition of the EGA [11], indicating that SiO 2 and MgO are the main constituents. It is also important to note in this table that alkaline, K 2 O, and earth alkaline, CaO, compounds exhibit relatively higher contents that may contribute to the formation of low temperature liquid phases.…”

“…The basic materials used in this work were an elephant grass ash (EGA) collected as bottom ash in a ceramic furnace of an industry in the municipal area of Campos dos Goytacazes, north of the state of Rio de Janeiro, Brazil. A preliminary characterization of this EGA was presented elsewhere [11]. The clay body employed as matrix for EGA incorporation was supplied by the Cerâmica Sardinha, a ceramic firm located in Campos dos Goytacazes.…”

“…Moreover, the EGA incorporation did not apparently affected both the ceramic water absorption and flexural strength. As a continuation of that previous wok [11], the present one investigated the influence of other firing temperatures on the microstructural and technological properties of clay ceramics incorporated with EGA.…”

“…A specific biomass ash is that obtained from incineration of elephant grass (Pennisetum pupureums Shaum), which has been cultivated in Brazil mainly as cattle fodder, but also used as fuel in ceramic industries. In a recent work [11] a preliminary characterization was performed on elephant grass ash (EGA) incorporated clay ceramics fired at 850ºC. In that work it was found by X-ray diffraction that the EGA is composed of quartz as well as calcium based sulphate, phosphate and carbonate.…”