Silica, ground

Ground silica, generally available below 300 mesh in size (5 m2/g), is used as a cheap heat resistant filler for a variety of compounds. There is no effect on the rate or state of cure. 

In the production process used by National Lead Industries, a solution of chromic acid is added to an aqueous slurry of lead oxide, finely ground silica, and a small amount of basic lead acetate ... 

Figure 5. Diagram of prepulse system. A 2nd harmonic generator B 3rd or 4th harmonic generator C 97% reflector D 50% UV beamsplitter or pellicle E 99% reflector (variable delay) F 99% reflector G sample cell H polarizer J spectrograph input mirror K ground silica diffuser L1-3 lenses M spectrograph.

Fig. 11.6 Effects of partial replacement of cement by finely ground silica on the compressive strengths of mixes cured normally and in the autoclave. After Mcnzcl (MHO).

The common availability of silica is not the sole reason for its extensive use. Probably, it is the chemical inertness and durability of silica which determined its popularity. The fillers discussed here include not only natural minerals but also a variety of synthetic products. Natural products can be divided into crystalline and amorphous. Crystalline silica fillers include sands, ground silica (or silica flour), and a form of quartz - tripoli, whereas the amorphous types include diatomaceous earth. 

Names sand, silica flour, ground silica... 

Siivo Bond. [Unimin Specialty Minerals] Ground silica fill, flatting agent for paints, mastics, adhesives, bu g compds., elec, qroxy conq)ds. 

SYNONYMS finely ground silica, randanite, silica four, tripoli. 

Chem. Descrip. Ground silica Chem. Analysis SiOj (99.6-99.8%)... 

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