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Pebbly Hills Project Overview.

Silicon Metal or Ferrosilicon

Pebbly Hills Project has always advertised the Pebbly Hill Project deposit silica to be of a high purity type and when extracted and processed (washed and screened) formed the primary feedstock for the manufacture of various grades of silicon including metallurgical grade silicon (“MGS”) and high purity electronic grades (“EGS”) and solar grades (“SGS”).

 PHP documented chemical properties and granulometric observations on the samples taken by MDS in 2004 and the Camden Geoserve CPR 2011 supported this view. At that time, the following chemical properties of the silica product defined the suitability of either MGS production or ferrosilicon (Table 1). Now in 2017 the specifications for ferrosilicon or silicon metal has changed (Table 2).


Table 1:    The Major element Specs for silicon manufacture (2011)

Silicon metal production in 2017 requires lump silica to be very pure with at least 99.5% silica (SiO2), while specifications for iron oxide (Fe2O3) impurities range from 0.05% to 0.10%, alumina (Al2O3) from 0.10% to 0.20% and titanium dioxide (TiO2) up to 0.006%, CaO and MgO impurities must be no more than 0.2% and P and As must be avoided. Resistance to thermal shock is critical and the product should retain at least 80% on a 12.5 mm screen after undergoing thermal shock. PHP testwork to date shows preliminary test work meeting this requirement

Table 1: 2017 General chemical and physical specifications for different uses of silica

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