Abstract: The objective of this study is to investigate the effect of adding coal to obtain insulating ceramic product. The preparation of mixtures is achieved with 04 types of different masse compositions, consisting of gray and yellow clay, and coal. Analyses are performed on local raw materials by adding coal as additive. The coal content varies from 5 to 20 % in weight by varying the size of coal particles ranging from 0.25mm to 1.60mm.
Initially, each natural moisture content of a raw material has been determined at the temperature of 105°C in a laboratory oven. The Influence of low-coal content on absorption, the apparent density, the contraction and the resistance during compression have been evaluated. The experimental results showed that the optimized composition could be obtained by adding 10% by weight of coal leading thus to insulating ceramic products with water absorption, a density and resistance to compression of 9.40 %, 1.88 g/cm3, 35.46 MPa, respectively. The results show that coal, when mixed with traditional raw materials, offers the conditions to be used as an additive in the production of lightweight ceramic products.
Abstract: This paper studies the application of a variety of
sawdust materials in the production of lightweight insulating bricks.
First, the mineralogical and chemical composition of clays was determined. Next, ceramic bricks were fabricated with different
quantities of materials (3–6 and 9 wt. % for sawdust, 65 wt. % for grey clay, 24–27 and 30 wt. % for yellow clay and 2 wt% of tuff).
These bricks were fired at 800 and 950 °C. The effect of adding this sawdust on the technological behaviour of the brick was assessed by
drying and firing shrinkage, water absorption, porosity, bulk density
and compressive strength. The results have shown that the optimum
sintering temperature is 950 °C. Below this temperature, at 950 °C,
increased open porosity was observed, which decreased the compressive strength of the bricks. Based on the results obtained, the
optimum amounts of waste were 9 wt. % sawdust of eucalyptus, 24 wt. % shaping moisture and 1.6 particle size diameter. These percentages produced bricks whose mechanical properties were
suitable for use as secondary raw materials in ceramic brick
production.