|Budget Amount *help
¥35,100,000 (Direct Cost : ¥35,100,000)
Fiscal Year 1993 : ¥4,000,000 (Direct Cost : ¥4,000,000)
Fiscal Year 1992 : ¥6,300,000 (Direct Cost : ¥6,300,000)
Fiscal Year 1991 : ¥24,800,000 (Direct Cost : ¥24,800,000)
The phase equilibrium relations on the following three sulfide systems have been studied by means of hydrothermal synthesis in the profect for three years. The Fe-Mn-Zn-S system, including common ore minarals of sphalerite, pyrrhotite, and alabandite, the Pb-Ag-Bi-S system of many kinds of Ag-sulfosalts minerals, and the Fe-Ni-S system containing most of Ni-ore minerals.
The Fe-Mn-Zn-S system ; The phase equilibrium relations of the system have been determined at 350ﾟC under hydrothermal conditions, Sphalerite could contain considerable amount of both Fe and Mn, while alabandite contains Fe but no Zn. Wurtzite, which has been known as a high temperature polymorph of sphalerite (1020ﾟC) exist stably at low temperature as 350ﾟC, because of containing Mn, and has a wide area of solid solution in the phase diagram of this system.
The Pb-Ag-Bi-S system ; Asa results of hydrothermal experiments of the system at 400ﾟC, the following nine menerals were synthesized. Galena-matildite ss., galenobismutite, lillianite, cannizzarite, heyrovskite, pavonite, benjaminite, bismuthinite, and argentite. Most of minerals have a solid solution by substitution of Ag^+ + Bi^<3+> = Pb^<2+>. Galena-matildite ss. has still complete solid solution between two minerals and lillianite homologous series (Macovicky & Karup-Mphiller, 1970) was synthesized first in this experiments. The phase diagram of the system at 400ﾟC was obtained under hydrothermal conditions.
The Fe-Ni-S system ; The system which has been almost completely determined above 500ﾟC, was studied by hydrothermal synthesis at 400ﾟC, and the phase relations of the system were made clear. MSS is still stable as a perfect solid solution between FeS and NiS.