BORON-ADDED PUMICE BRICK PRODUCTION: DETERMINATION OF PHYSICOMECHANICAL AND CHEMICAL PROPERTIES

In Turkey, colemanite and borax minerals are produced in boron processing plants located respectively in Emet and Kırka. In addition, there are lots of pumice deposits in various regions of the country. Within the scope of this work, it is aimed to produce bricks which are fireproof, light, with high strength, and earthquake resistant for building and construction sector by employing strategically important boron minerals as well as their wastes. Boron minerals were used within the pumice aggregate as much as 6-12% by taking advantage of its binding properties. Experimental studies were carried out in laboratories located at Mineral Research and Exploration General Directory. Appropriate sizes of pumice (0-8 mm) and other boron minerals were mixed in the presence of clay and carboxymethylcellulose, CMC, to prepare dry mixture. Sufficient amount water forming a semi-dry mixture was then added. The semi-dry mixture was then compressed into molds with 10-20 bar pressure. The green-bodies were subsequently left natural drying. The dried samples were fired at 700-850 oC for 2 h. The final composition containing pumice, tincal, colemanite, boron waste, clay, and CMC was determined at the end of the laboratory work. Specifically, CMC in the composition kept between 0.5-1.5%. Mechanical, physical, and chemical experiments were carried out on baked products according to Turkish Standards Institution and international standards. On the best sample, thermal conductivity (0.1939 W/mK) and compressive strength (3.63 MPa) were measured. The bulk density (0.62 g/cm3), water absorption (32%) and apparent porosity (37.1%) by Archimedes method were determined. The results were also compared with similar bricks. It was determined that the bricks can be produced in industrial size (5x10x20 cm3).