SELECTIVE BATCHING FOR IMPROVED COMMERCIAL GLASS MELTING

摘要

In the typical method for melting raw materials for commercial glass production preferential reactions between alkali and alkaline earth carbonates could result in the formation of a low viscosity liquid that segregates from sand grains, thus promoting the segregation of the batch after introduction into the furnace. If true, then segregation can substantially increase the time required to form a homogeneous melt. The large raw material particle size necessary to reduce dusting problems further increases the time required for melting and reaction. To improve the melting efficiency, and to control the reaction paths during the melting process, selective batching was introduced in which reactions between the alkali and alkaline earth carbonates were eliminated or reduced, promoting reactions between the fluxes and quartz earlier in the melting process. In this study two intermediate materials of {Na_2CO_3+SiO_2} and {CaCO_3+MgCO_3·CaCO_3+SiO_2} are prepared by the selective batching process, subsequently mixed mechanically, and introduced into the furnace. The data indicate that from 81-92% reductions in melting times are possible through a combination of reduced raw material particle size and controlled reaction paths during the melting process. Preliminary results suggest that, in addition to energy savings, selective batching has other potential benefits, including: reduced emissions, shorter fining times, increased throughput, and increased refractory lifetimes.