Keen Interest in Reducing the Cost of Tile Production
Worldwide demand for floor and wall tiles has been on the increase for many years. Production has doubled since the year 2000. Most of the manufacturing (70 % of worldwide production volumes) takes place in the Asian countries.
When supply exceeds domestic demand, tiles are exported to the rest of the world. As a result, competitive pricing is vital for any producer. The amount of money spent on energy is a major cost factor in ceramic tile production. A number of innovations and improvements have been introduced to enhance the drying and firing process in recent years. Little has changed however in the preparation of compounds used for dry pressing in tile production. Natural gas and oil are normally used as heating fuels for the wet ball mills and spray dryers. At temperatures between 450–600 °C, the water content of ceramic body slurries is reduced from perhaps 35 % to a residual level of 6–7 %. At Tecnargilla 2014 (22–24.09.2014. Rimini), EIRICH/DE presented a technique based on build-up agglomeration for producing granulate for the pressing process. During the drying process, the moisture content of the granules only needs to be reduced from 11 to 6 % respectively, which has considerable advantages from the energy standpoint. Build-up agglomeration using the EIRICH mixing granulator has a proven track record in many industries including ceramics. A tile producer in Germany began using this type of system back in 1986. In the past, oversize grains had to be removed by screening and re-processed, which was a disadvantage. This step is no longer needed. Over the past few years, EIRICH has developed an advanced grain standardization process suitable for industrial-scale use with ceramic compounds based on techniques used in the food and pharmaceutical sectors. In conjunction with build-up agglomeration, in-spec grain yields approaching 100 % are now achievable. The granulate is comparable with spray grains and is even suitable for production of large tiles. Combined use of granulate production with the EIRICH mixing granulator and grain standardization with the EIRICH-Pellet Sizer® can have substantial benefits for tile producers. This is the case at a large producer in Thailand, for example. At a production rate of 32 t/h, the annual savings exceed USD 3,5 million. Besides a reduction in energy costs, there are also other advantages. The current build-up agglomeration process eliminates or significantly reduces need for organic lubricants and binders. This in turn reduces emissions from the drying and firing process. This is why EIRICH has named the new process EcoPrep®. In recent years, a number of suppliers have developed spray wetting techniques suitable for mass production which promise to offer similar improvements in energy efficiency. In contrast to those methods however, granulate with flow properties similar to those of spray grains can be produced using the EIRICH process, making it possible to produce large, high-quality tiles.