PHASES K_H; KH = K+ - H+; -no_check

SOLUTION 1 pH 11; K 1 K_H 8; Al 1 K-feldspar; Si 1 K-mica

USE solution 1EQUILIBRIUM_PHASESMackinawite 0 10Greigite 0 10

PHASES Mackinawite FeS + H+ = Fe+2 + HS- log_k -4.648 delta_h -0 kcal Greigite Fe3S4 + 4H+ = 2Fe+3 + Fe+2 + 4HS- log_k -45.035 delta_h -0 kcal Pyrite FeS2 + 2H+ + 2e- = Fe+2 + 2HS- log_k -18.479 delta_h 11.3 kcalSELECTED_OUTPUT -file Phase test.sel -activities Fe+2 H+ HS- Fe+3 -si Mackinawite Greigite Pyrite -equilibrium Mackinawite Greigite Pyrite ENDPHASES Fe_H2; FeH2 = Fe+2 - 2H+; -no_checkENDUSER_GRAPH 1 -headings Greigite/Mackinawite -initial_solutions true -axis_titles "Log activity of H2(aq)" "Log activity (Fe+2/H+^2)" "" -start10 PLOT_XY LA("H2"), SI("Fe_H2"), color = Black, symbol = None -endSOLUTION 1 pH 11 ; Fe(2) 1 Fe_H2 8; Fe(3) 1 Mackinawite; S(-2) 1 GreigiteSOLUTION 3 pH 6; Fe(2) 1 Fe_H2 1; Fe(3) 1 Greigite; S(-2) 1 MackinawiteENDUSER_GRAPH -headings Greigite/Pyrite 10 PLOT_XY LA("H2"), SI("Fe_H2"), color = Red, symbol = None SOLUTION 2pH 10 charge ; pe -8 Fe_H2 20; Fe 1 Pyrite; S 1 GreigiteSOLUTION 4 pH 8 charge; pe -8 Fe_H2 14; Fe 1 Pyrite; S 1 Greigite