Utilization of recycled paper processing residues and clay of different sources for the production of porous anorthite ceramics

Abstract

Production of porous anorthite ceramics from mixtures of paper processing residues and three different clays are investigated. Suitability of three different clays such as enriched clay, commercial clay and fireclay for manufacturing of anorthite based lightweight refractory bricks was studied. Porous character to the ceramic was provided by addition of paper processing residues (PPR). Samples with 30-40 wt% PPR fired at 1200-1400• C contained anorthite (CaO·Al 2 O 3 ·2SiO 2 ) as major phase and some minor secondary phases such as mullite (3Al 2 O 3 ·2SiO 2 ) or gehlenite (2CaO·Al 2 O 3 ·SiO 2 ), depending on the calcite to clay ratio. Anorthite formation for all clay types was quite successful in samples with 30-40 wt% of paper residues fired at 1300• C. A higher firing temperature of 1400• C was needed for the fireclay added samples to produce a well sintered product with large pores. Gehlenite phase occurred mostly at lower temperatures and in samples containing higher amount of calcium (50 wt% PPR). Compressive strength of compacted and fired pellets consisting of mainly anorthite ranged from 8 to 43 MPa.

Production of anorthite refractory insulating firebrick from mixtures of clay and recycled paper waste with sawdust addition

“…previous study of the authors [15]. This was because the sawdust addition was expected to supply additional heat to the sample during firing and hence samples may warp due to premature melting.…”

“…In order to increase the amount of porosity in the samples, wooden sawdust with particle size smaller than 3 mm was used as burnout pore-making additive as well as the paper waste. The mixtures containing clay and 30 wt% paper waste (on dry basis) that supplied the strongest anorthite composition [15] were prepared for production of the samples. Recycled paper processing waste was in sludge form.…”

“…Recently, there has been considerable research on the reuse of pulp and paper industry wastes as a new source of raw material or pore-former in the ceramic materials due to their organic and inorganic contents [10][11][12][13][14][15]. A patent was reported on how to produce low density ceramics from paper recycling residuals [11].…”

“…However, in this invention, the intervals of parameters for producing ceramics are not sufficiently defined. In a previous study by authors [15], production of porous anorthite ceramics from mixtures of paper processing residues and three different clays (enriched clay, K244 clay and fireclay) were investigated. Paper processing residues composed of calcium carbonate (as CaO source) and fine cellulose fibers (as pore former) were used as an additive to clay raw materials to make porous anorthite ceramic.…”

Elaboration and characterization of mullite-anorthite-albite porous ceramics prepared from Algerian kaolin

“…Other studies [23,24] have confirmed that the presence of anorthite increases the strength and chemical stability of the material and improves its physical properties such as low thermal expansion coefficient, high thermal shock resistance, and low dielectric constant. Actually, porous anorthite ceramics with high compressive strength are obtained from mixtures of paper processing residues and clays [25]. Anorthite based ceramics with an important dielectric resistance were also prepared from kaolin DD2 and calcite [26].…”