The effect of P₂O₅ on the viscosity of haplogranitic liquid

The effect of P₂O₅ on the viscosity of a haplogranitic liquid has been determined at 1 atm pressure in the temperature interval of 700-1650°C. The viscosity decreases with the addition of P₂ O₅ at all temperatures investigated. The viscosity decrease is nonlinear, with the strongest decrease exhibited at low P₂O₅ concentration. The temperature-dependence of the viscosity of all the investigated liquids is Arrhenian, as is the case for P₂O₅ liquid. At temperatures corresponding to the crystallization of phosphorus-rich granitic and pegmatitic systems the addition of 1 wt.% of PO₂O₅ decreases the viscosity 0.2 log₁₀ units. -from Authors