Talk:Silica fume

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This entry was taken in whole from http://www.fhwa.dot.gov, a federal agency.

The conversion of 215,280 sq ft./lb to 20,000 sq meter/kg isn't right. 215,280 sq ft/lb = 20,000 sq. meter/lb. In sq meters/kg it's 44,000. I didn't edit the pages as I'm not sure which is right. Regardless, the conversion is wrong. I found the reference at http://www.fhwa.dot.gov and it contains these same numbers but one of them is certainly wrong. —Preceding unsigned comment added by 63.122.213.254 (talk) 16:21, 14 May 2008 (UTC)

I contacted fhwa.dot.gov and they are correcting the page that this information was taken from to read, "Silica Fume consists of very fine vitreous particles with a surface area ranging from 60,000 to 150,000 ft^2/lb or 13,000 to 30,000 m^2/kg." I'll edit the article to reflect this. Scot —Preceding unsigned comment added by 63.122.213.254 (talk) 17:45, 16 May 2008 (UTC)

Yes the site referenced by this wikipage is incorrect. It is true that 215, 280 ft²/lb = 44,000 m²/kg = 44 m²/g. Why anyone would write 215,280 ft²/lb is beyond me. m²/g are the typical units fumed silica is manufactured to and marketed under. And that is not the only issue with this wikipedia page.

Silica fume and fumed silica are basically the same thing with one exception. They are both made by condensing SiO2 vapor at high temperature (hence the need for a combustion of SiCl4). The word fumed means "of smoke" in both cases. Either can be made of low and high surface area (large and small primary particles of silica). The big difference is in marketing.

Fumed silica is a commodity product used in everything and it is made by a handful of companies around the world. A few companies have started producing LOW surface area (not high surface area but LOW surface area) fumed silica particles for the concrete market and are attempting to differentiate themselves. But again, both are "of smoke". —Preceding unsigned comment added by MNIN001 (talk • contribs) 02:28, 6 July 2010 (UTC)

Other issues. The container of "silica" shown in the picture is Cabot's EH-5 grade of "fumed silica" not of the self proclaimed "silica fume" for the concrete business. It is about the highest surface area fumed silica available. Not 17 to 30 m²/g "silica fume" as advertised on this website http://www.norchem.com/silica-fume.html

I'll suggest this. combine this wiki article and the fumed silica articles together and mention a marketing difference based on surface are and application.

Substituted transclusion for File
I substituted a transclusion of Template:Components of Cement, Comparison of Chemical and Physical Characteristics for File:Comparison of Chemical and Physical Characteristics Portland Cement - Fly Ash, Slag Cement, and Silica Fume.jpg, which had been flagged for translation to SVG, as if it were a graphic. But since it is really a table, I have re-rendered it in wiki markup. The references cited in the table have been freshly extracted from the source document of the table. I have done this change for each of the three articles in which that file was referenced (Concrete, Cement, and Silica fume).ArthurOgawa (talk) 23:23, 6 November 2014 (UTC)