Experimental Petrology and Metallurgy/Starting materials

Preparing starting mixes Synthetic compounds + Caption text Component (mostly oxides) Added as Motivation Notes Na2O Na2CO3 Oxide hygroscopic -- CaO CaCO3 Oxide hygroscopic -- K2O K2CO3 Oxide hygroscopic -- FeO Fe2O3 Oxide non-stoichiometric -- MgO MgO / Mg2SiO4 Oxide hygroscopic -- Al2O3 Al2O3 Fire at 1000 C before weighing -- Cr2O3 Cr2O3 Fire at 1000 C before weighing -- SiO2 SiO2 Fire at 1000 C before weighing -- P2O5 Ca3(PO4)2 Very hygroscopic -- CO2 Carbonates (see above) Heat gently before weighing. MgCO3 should be natural magnesite, as excess water is impossible to drive off the structure. -- H2O Mg(OH)2, Al(OH)3, PtO2.4H2O Liquid water difficult to weigh -- Decarbonation Put powders into a crucible Place in 1 atm furnace at room temperature Heat slowly (over at least two hours to avoid spitting during decarbonation) to around 200 K above decarbonation temperature. Gas mixing Pelletisation Gas mixing with H2-CO or CO-CO2. Make sure there is >20 mol% of both gases to ensure good control of fO2. Sol-gel Starting form Glasses Crystalline powder