Shock Wave Equation of State and Shock-Induced Melting of Melanterite

Shock compression experiments were conducted on melanterite samples with an initial density of 1.714 g/cm3 up to 100 GPa. The experimental data can be divided into a low-pressure region consisting of a partially molten state, and a completely liquid state at high-pressure. The shock velocity D is a linear function of the particle velocity u in these two regimes: D=0.59+2.06u for u3.12 km/s and D=3.18+1.223u for u3.12 km/s. K0S and K0S, the zero pressure adiabatic bulk modulus and its first pressure derivative of Birch-Murnaghan EOS (isentrope), are obtained in terms of shock Hugoniot data by using the Eulerian finite strain theory. Under the assumption =3.12(0/), then for the low pressure phase (0=1.898 g/cm3), K0S=3.72 GPa and K0S=4. We find 0=1.60 g/cm3, K0S=3.28 GPa and K0S=10.5 for the high pressure phase (liquid state), with a STP melting energy of 80 J/g and =1.46(0/). The melting curve of melanterite is determined according to Lindemann's law and can be approximately described as: pm(GPa) =0.159(Tm(K)/1000)6.3371+0.69.