Chapter 15. Using Surface Area to Solve an Inappropriate Mixing Problem

Summary

Sometimes, in spite of best intentions and established protocols, accidents occur. In this case, 50 000 lb (one truckload) of nepheline syenite was inappropriately added to a raw material silo containing 120 000 lb of quartz flour. Once this occurred, there were two options:dump the silo or figure out how to use the material. The immediate response was to dump the silo, however, that created a new problem: what to do with 170 000 lb of undesirable material. Knowing how to use the material required knowledge of the ratio of nepheline syenite to quartz, which was constantly changing due to funnel flow within the storage silo. Since the density of nepheline syenite and quartz is nearly identical, density was not a viable route to solving the problem. Data obtained from previous raw material testing provided a sufficient baseline to predict the ratio of nepheline syenite to quartz using surface area measurements. The ratios were independently verified through button-type melting tests.