Breaking down Silica Valley

• Autores: Cameron Perks
• Localización: Industrial Minerals, ISSN 0019-8544, Nº. 589, 2016 (Ejemplar dedicado a: Diciembre/Enero)
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Ascertaining market prices for HPQ is a difficult task. Part of the problem is the definition of HPQ differs depending on end use specifications. HPQ sand for solar PV-grade CZ crucible manufacture contains less than 30ppm impurities and semiconductor-grade material requires a maximum of 10ppm impurities. Elemental impurities also need to be within certain tolerances.

    End product specifications for HPQ are strict, with at least 99.995% purity required by most entry level, lower grade quartz applications. A silica content of at least 99.997% (<30ppm impurities) is required for high-end applications like CZ crucibles and quartzware machine parts for the solar industry, while the semiconductor industry requires purity of 99.999% (<10ppm impurities). Solar grade HPQ must contain less than 30ppm impurities after processing. If quartz cannot be economically processed to these levels, it cannot be used for high value applications and is only suitable for entry level uses, such as halogen lighting and liquid crystal display (LCD) TV substrates.