TITLE Example 6A.--React to phase boundaries. SOLUTION 1 PURE WATER pH 7.0 charge temp 25.0 PHASES Gibbsite Al(OH)3 + 3 H+ = Al+3 + 3 H2O log_k 8.049 delta_h -22.792 kcal Kaolinite Al2Si2O5(OH)4 + 6 H+ = H2O + 2 H4SiO4 + 2 Al+3 log_k 5.708 delta_h -35.306 kcal K-mica KAl3Si3O10(OH)2 + 10 H+ = 3 Al+3 + 3 H4SiO4 + K+ log_k 12.970 delta_h -59.377 kcal K-feldspar KAlSi3O8 + 4 H2O + 4 H+ = Al+3 + 3 H4SiO4 + K+ log_k 0.875 delta_h -12.467 kcal SELECTED_OUTPUT -file ex6A-B.sel -activities K+ H+ H4SiO4 -si Gibbsite Kaolinite K-mica K-feldspar -equilibrium Gibbsite Kaolinite K-mica K-feldspar END TITLE Example 6A1.--Find amount of K-feldspar dissolved to reach gibbsite saturation. USE solution 1 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 KAlSi3O8 10.0 Kaolinite 0.0 0.0 K-mica 0.0 0.0 K-feldspar 0.0 0.0 END TITLE Example 6A2.--Find amount of K-feldspar dissolved to reach kaolinite saturation. USE solution 1 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 0.0 Kaolinite 0.0 KAlSi3O8 10.0 K-mica 0.0 0.0 K-feldspar 0.0 0.0 END TITLE Example 6A3.--Find amount of K-feldspar dissolved to reach K-mica saturation. USE solution 1 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 0.0 Kaolinite 0.0 0.0 K-mica 0.0 KAlSi3O8 10.0 K-feldspar 0.0 0.0 END TITLE Example 6A4.--Find amount of K-feldspar dissolved to reach K-feldspar saturation. USE solution 1 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 0.0 Kaolinite 0.0 0.0 K-mica 0.0 0.0 K-feldspar 0.0 KAlSi3O8 10.0 END TITLE Example 6A5.--Find point with kaolinite present, but no gibbsite. USE solution 1 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 KAlSi3O8 10.0 Kaolinite 0.0 1.0 END TITLE Example 6A6.--Find point with K-mica present, but no kaolinite USE solution 1 EQUILIBRIUM_PHASES 1 Kaolinite 0.0 KAlSi3O8 10.0 K-mica 0.0 1.0 END TITLE Example 6B.--Path between phase boundaries. USE solution 1 EQUILIBRIUM_PHASES 1 Kaolinite 0.0 0.0 Gibbsite 0.0 0.0 K-mica 0.0 0.0 K-feldspar 0.0 0.0 REACTION 1 K-feldspar 1.0 0.04 0.08 0.16 0.32 0.64 1.0 2.0 4.0 8.0 16.0 32.0 64.0 100 200 umol END TITLE Example 6C.--kinetic calculation SOLUTION 1 -units mol/kgw Al 1.e-13 K 1.e-13 Si 3.e-13 EQUILIBRIUM_PHASES 1 Gibbsite 0.0 0.0 Kaolinite 0.0 0.0 K-mica 0.0 0.0 KINETICS 1 K-feldspar # k0 * A/V = 1e-16 mol/cm2/s * (10% fsp, 0.1mm cubes) 136/cm = 136.e-13 mol/dm3/s -parms 1.36e-11 -m0 2.16 -m 1.94 -step_divide 1e-6 -steps 1e2 1e3 1e4 1e5 1e6 1e7 1e8 INCREMENTAL_REACTIONS true RATES K-feldspar -start 10 REM store the initial amount of K-feldspar 20 IF EXISTS(1) = 0 THEN PUT(M, 1) 30 REM calculate moles of reaction 40 SR_kfld = SR("K-feldspar") 50 moles = PARM(1) * (M/M0)^0.67 * (1 - SR_kfld) * TIME 60 REM The following is for printout of phase transitions 80 REM Start Gibbsite 90 if ABS(SI("Gibbsite")) > 1e-3 THEN GOTO 150 100 i = 2 110 GOSUB 1500 150 REM Start Gibbsite -> Kaolinite 160 if ABS(SI("Kaolinite")) > 1e-3 THEN GOTO 200 170 i = 3 180 GOSUB 1500 200 REM End Gibbsite -> Kaolinite 210 if ABS(SI("Kaolinite")) > 1e-3 OR EQUI("Gibbsite") > 0 THEN GOTO 250 220 i = 4 230 GOSUB 1500 250 REM Start Kaolinite -> K-mica 260 if ABS(SI("K-mica")) > 1e-3 THEN GOTO 300 270 i = 5 280 GOSUB 1500 300 REM End Kaolinite -> K-mica 310 if ABS(SI("K-mica")) > 1e-3 OR EQUI("Kaolinite") > 0 THEN GOTO 350 320 i = 6 330 GOSUB 1500 350 REM Start K-mica -> K-feldspar 360 if ABS(SI("K-feldspar")) > 1e-3 THEN GOTO 1000 370 i = 7 380 GOSUB 1500 1000 SAVE moles 1010 END 1500 REM subroutine to store data 1510 if GET(i) >= M THEN RETURN 1520 PUT(M, i) 1530 PUT(TOTAL_TIME, i, 1) 1540 PUT(LA("K+")-LA("H+"), i, 2) 1550 PUT(LA("H4SiO4"), i, 3) 1560 RETURN -end USER_PRINT 10 DATA "A: Gibbsite ", "B: Gibbsite -> Kaolinite ", \ "C: Gibbsite -> Kaolinite ", "D: Kaolinite -> K-mica ", \ "E: Kaolinite -> K-mica ", "F: K-mica -> K-feldspar" 20 PRINT " Transition Time K-feldspar LA(K/H) LA(H4SiO4)" 30 PRINT " reacted" 40 PRINT " (moles)" 50 FOR i = 2 TO 7 60 READ s$ 70 IF EXISTS(i) THEN PRINT s$, GET(i,1), GET(1) - GET(i), GET(i,2), GET(i,3) 80 NEXT i SELECTED_OUTPUT -file ex6C.sel -reset false USER_PUNCH -head pH+log[K] log[H4SiO4] 10 PUNCH LA("K+")-LA("H+") LA("H4SiO4") END