An investigation of the silica deposits of southern Illinois . that each sample contained the same amount of the various sized part-icles. Portions of each saraple were mixed v;ith the various bonding agents used,water added, and were then molded into test pieces. Sets of trial pieces con-taining two trials for each sample and binder were burned to different temper-atures. The complete series contained, therefore, two trial pieces for eachsample and binder and for each temperature burned to. Cones were employed formeasuring the temperature with a pyrometer to check. The apparent specificgravit
An investigation of the silica deposits of southern Illinois . that each sample contained the same amount of the various sized part-icles. Portions of each saraple were mixed v;ith the various bonding agents used,water added, and were then molded into test pieces. Sets of trial pieces con-taining two trials for each sample and binder were burned to different temper-atures. The complete series contained, therefore, two trial pieces for eachsample and binder and for each temperature burned to. Cones were employed formeasuring the temperature with a pyrometer to check. The apparent specificgravities of each trial piece were determined by determining the loss of weightv/hen suspended in water. The results obtained were plotted against temperature,giving curves for each sample and binder, showing the effect of temperature onthe specific gravity. A comparison of the curves for each sample shows theeffect of the binder upon the rate of inversion or change in specific gravity. FIRST SERIES:- The raw materials were crushed in a jaw crusher and then passed. 15. thru screens and sized. Weighed amoimts of the various sized materials were mixed together thoroughly in the following proportions:- ^ of Material caught % of Material passing on Screens of through a 10-mesh 20-mesh 30-mesh 40-meeh 40 mesh Screen 10^ 15^ 5^ 5^ 65^ This corresponds approximately to the medium grind used for silica brick accord-ing to MacDowells screen analysis.^ Enough of each sample was weighed out to make twenty one cubes and 2^ ofthe binder was added to each batch. Where a salt was used enough was added tocorrespond to 2^ of the oxide. The sample and binders were mixed together thor-oughly by hand and enough water was added to make the mass v/oikable. This variedwith the material, the novaculite requiring 18/^, the gannister and white silica,25^. Thi 8 was due to the fact that the latter two materials contained much finerlparticles in the portions that passed through the 40 mesh sieve,which was thefr
Size: 1341px × 1864px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectminesandmineralresou
