Djambazov S.Yoleva A.Chervenliev P.Georgiev A.2024-07-162024-07-162024-07-162024-07-162015-01-011314-79781314-7471SCOPUS_ID:84937841482https://rlib.uctm.edu/handle/123456789/1103The effect of amorphous silicate and zeolite on the thermal conductivity and porosity of ceramic building bricks is studied. The aim of the present work is to produce porous bricks of reduced thermal conductivity and acceptable compressive strength by using a combination of natural raw materials (amorphous silicate and zeolite) as well as sawdust and coal dust as pore forming agents. Clay from Lucovite deposits is used as the main component of the ceramic bodies (over 60 %). The content of amorphous silicate is increased from 7 mass % to 20 mass %, while that of zeolite - from 7 mass % to 30 mass %. The green samples are prepared by plastic extrusion. After moulding and drying at 100oC, the samples are fired at 800oC and 850oC for one hour. Then their water absorption, apparent density and apparent porosity, mechanical compressive strength and thermal conductivity are analyzed. It is found that the amorphous silicate has a small effect on the properties of the bricks obtained. The bricks containing zeolite have low?r thermal conductivity and higher porosity when compared to those of other compositions. A tendency of thermal conductivity decrease and porosity increase with zeolite quantity increase is found at both firing temperatures. Bricks of improved properties are prepared at the lower firing temperature. The highest porosity (36,00 %) and the lowest thermal conductivity (0,67 W/mK) is obtained in case of bricks containing 30 % zeolite and firing temperature of 800oC. The results of this work show that building bricks of lower thermal conductivity and higher porosity can be produced at a lower firing temperature by introducing zeolite to their composition. They are a potential heat insulating material.enArticle