Serpentine powder

Serpentine Powder. BlkPdr ground dry to a flourlike compn. At about the middle of the fifteenth century it was supplanted by corned powder (See also under Black Powder or Gunpowder in Vol 2, B169-L)... 

Figure 20.1 Micrographs of nanoscaled fillers (a) serpentine powder, (b) Ser-KAc compound, (c) worm-Uke EG, (d) and (e) FESEM (Field Emission Scanning Electron Microscopy) for nano-EG. Panel (d) denotes the whole micrograph and panel (e) indicates the enlarged micrograph in the rectangular region.

Wilson, S.A., Raudsepp, M., Dipple G.M. 2006. Verifying and quantifying carbon fixation in minerals from serpentine-rich mine tailings using the Rietveld method with X-ray powder diffraction data. American Mineralogist, 91, 1331-1341. 

In this year is the earliest known reference to corned powder. It was in the Firebook of Conrad von Schongau and listed in Marshall 1 (Ref 11, p 25). Corning means that the BkPdr cake was broken into small grains instead of preparing it in fine powder, known as serpentine . The process was essentially the same as described in Vol 2 of Encycl, p B169-L... 

In Finland, investigations into stepwise carbonation processes initially involved the use of Finnish serpentine and (calcined) magnesium hydroxide powder ( 20gm, 99% pure) in a PTGA with humid C02, at 0.1 to 3.5 MPa pressure. The materials were first heated to 1273 K, and then cooled in (mainly) C02/N2 mixtures. Tests conducted at elevated pressures did not produce the expected increase in MgO carbonation rate, as the final carbonation conversions fell from 5.6% at 0.1 MPa to 2.9% at 3.5 MPa in 99%/l% C02/H20. Hence, the decision was taken to proceed with Mg(OH)2 under test conditions where MgO formation was thermodynamically unfavorable [85, 96]. 

Deer, Howie and Zussman (19J give physical and optical constants for amphibole minerals in Vol. two, Rock Forming Minerals, (chain silicates), and for Serpentine minerals (chrysotile) in volume three (sheet silicates). X-ray diffraction data is obtainable from the Powder Diffraction file, Inorganic (20). This data can be used for a double check of asbestos standards. 

When adding serpentine, magnesia powder or magnesite as Mg-bearing fluxes info the hematite pellets, the strength of both preheated and roasted pellets decreased as the MgO content increased. 

Mixtures of serpentine minerals in soils can be separated with reasonable confidence by electron micrography. Tubular and lathlike crystals are chrysotile platy or broadly lathlike crystals are probably antigorite. The other serpentine minerals cannot be separated from antigorite by this means, or in mixtures, even by X-ray powder patterns, but they are uncommon constituents of soils and may generally be assumed to be absent. 

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