The effect of composition on the ferric-ferrous ratio in basaltic liquids at atmospheric pressure

Geochmuca

er Cosmochmuco

Acto Vol. 44. pp. 525 to 532

Perpamon Press Ltd 19X0. Prmted m Great Britam

The effect of composition on the ferric-ferrous ratio in basaltic liquids at atmospheric pressure CARL R. THORNBER*. PETERL. ROEDERand J. ROBERTFOSTER N.L. Bowen Research Laboratory, Department of Geological Sciences, Queens University,

Kingston, Ontario, Canada (Reraivrd

21 March 1979:

accepted

in reaisedform

9 November

1979)

Abstract-The

effects on the ferric-ferrous ratio of varymg individual components in a dry basaltic liquid have been determined at atmospheric pressure and constant oxygen fugacity (f0,). Experiments were conducted by suspending 100 mg samples from pt loops at 1200-C (f0, = 10-satm) and 1360°C (fOz = lo-” atm) in an atmosphere controlled by mixtures of CO2 and Hz. A ~cro~alytical wetchemical technique and the electron microprobe were used to determine the composition of the resulting basaltic glasses. In order of decreasing significance, the addition of oxides of K, Na, Si, Al, or Ca produces an increase in the ferric-ferrous ratio of the melt at 1200°C. The change in the ferric-ferrous ratio produced by component addition is less at 136O’C than at 12OO’C.

TEMPERATURE,pressure

and bulk composition are interdependent variables controlling the ratio of ferric to ferrous iron in rock melts. Relative variations of the ferric-ferrous ratio of a silicate melt caused by changes in temperature and the fugacity of oxygen (f0,) at constant total pressure can be explained using thermodynamic equations to express the equilibrium reaction between simple ferric and ferrous oxides: the proportion of ferric to ferrous species increases with increasing f0, at constant temperature and decreases with increasing temperature at constant f02. Evidence confir~ng this general behavior of the ferric-ferrous ratio of magmas is provided by experiments of KR\INEDY(1948) and FUDA~I(1965). who use natural starting materials heated at atmospheric pressure and controlled temperature and f02. Increased pressure results in progressive ferric iron reduction, as indicated by DRICKAMERer al. (1969) for synthetic materials compressed to as much as 200 kbar. Recent attempts to rationalize ferric-ferrous changes with pressure in experiments more relevant to magmatic systems (GAFF, 1977: MYSENand VIRGO, 1978) indicate the same generai trend in reduction of ferric iron as pressure increases. The magnitude of this effect appears to depend upon composition and is interpreted as being related to structural variations in silicate melts. The illustrated effects of fO,, temperature and pressure on the ferric-ferrous ratio, along with the evidence of FUDALI (1965) for a discrete dependency of the ratio upon bulk composition of rock melts,

* Present address: U.S. Geological Survey. 959 National Center, Reston. VA 22092, U.S.A. + The 401 diabase was collected for this investigation at the intersection of highways 15 and 401 in Kingston, Ontario, Canada. The same starting material was used bg HILL and ROEDER (1974) and HAUGHTONet d. (!974) and designated RHBI and DHBZ. respectively.

confirm that redox equilibria in natural silicate liquids are exceedingly complex. Quantification of the relation between the measured ferric-ferrous ratio of a rock and its equilibrium oxygen fugacity requires a more complete knowledge of the factors controlling oxidation or reduction of iron in silicate melts. It is probabie that Fe3+ and Fe’+ cations involved in redox reactions are incorporated in liquid poiymers, or complex anions, which vary in structure and composition as composition and physical conditions of a melt change. An evaluation of the specific effects of individual elements on relative proportions of ferric to ferrous iron in compositionaIly complex silicate liquids is therefore a prerequisite to an understanding of redox geochemistry in magmas. The present authors have investigated the effects on the ferric-ferrous ratio of varying individual components in a basaltic liquid equilibrated at atmospheric pressure and controlled temperature and f02. Results of this investigation provide a basis for evaluating concentrations of ferric and ferrous iron in silicate melts and thus may be used to improve models of magmatic crystallization in terrestrial and planetary crustal environments. A general predictive equation describing how the ferric-ferrous ratio of basaltic liquid varies with bulk composition is presented by THORNBER (1977). Attempts to derive an equation stating the concise relation of Fe3+,/Fe2+ variation with temperature and bulk composition of silicate melts have not been altogether satisfactory, due to limitations of the current data base. EXPERIMENTAL AND ANALYTICAL METHODS Effects of melt composition on the ferric-ferrous ratio have been determined by adding major oxide components to a natural material of tholeiitic basalt composition (401 d&base).+ Experiments were conducted at about liquidus temperature (1200°C) and

C. R. THORNBER, P. L. ROEDER and J. R. F~S.TER

526

S

0

2

4

6

8

10 RUN

Fig. 1. Equilibration

12 TIME

14

16

20

I8

22

24

(HOURS)

time as a function of the ferric-ferrous ratio using 401 powder melted at 12OO’C and at an f02 of 10-s atm as a liquid droplet.

at a temperature well above the liquidus temperature (1360°C). Oxygen fugacity values of lo-* and 10e6 atm, respectively, were chosen to approximate conditions in terrestrial magmas at these temperatures, as summarized by HAGGERTY(1976). The 1,T vs log fO2 relation defined by our experimental conditions is slightly above and parallel to the fayalitemagnetite-quartz buffer as defined by EUCSTERand WONES (1962). Powdered starting materials were compressed into pellets, fused to a looped platinum wire using a strip furnace, and suspended in a vertical quench-furnace, which had an fO2 controlled by a mixture of carbon dioxide and hydrogen gases. Samples were dropquenched at the furnace bottom in the gas mixture, thereby minimizing oxidation. The sample holding technique (DONALDSONet al., 1975) virtually eliminated iron loss resulting from crucible-melt reaction and minimized time required for gas-melt equilibration. Figure 1 represents the ferric-ferrous ratio in the melt as a function of time, at 1200°C and an fO2

of lo-’ atm. Reproducibility of ferric-ferrous ratio values of glasses quenched from liquids indicates that equilibrium conditions should prevail in runs lasting more than 5 hr. The liquid droplet experimental technique has proven to be considerably more efficient, in terms of required run time. than conventional procedures in which corrosive basaltic liquids are enveloped in crucibles for a minimum of 24-48 hr (KENNEDY, 1948; FUDALI. 1965; HILL, 1969; HAUGHTCIN et a/., 1974). Comparison of ‘time-equilibration’ data of the above investigators indicates that the time required for oxidation ratio stabilization in rock melts decreases with increasing temperature at constant fO2 and increases slightly with increasing fO2 at. constant temperature. Therefore, for experiments at 1360°C and an f02 of 10e6, runs lasting only 4-6 hr were considered optimum in order to avoid excess vaporization of alkalies. The experimental technique used restricted sample weight to less than 1OOmg and required precise methods of chemical microanalysis for the detection

Table 1. Wt% Fe0 obtained on reference materials SY2 and MRGI before and after correction Batch number

SY2

1

3.40

2

MRCl After correction

Obtained value *

Obtained value

After

cotrection

3.57

8.32

8.74

3.76

3.61

8.97

8.61

3

3.64

3.68

8.37

a.45

4

3.58

3.65

a.25

8.42

5

3.49

3.59

0.39

8.64

No.

Determinations

14

3.57

SD

Recommended Value

13

3.62

0.14

a.57

a.46

0.29

3.59

8.61

Ferric-ferrous

ratio in basaltic liquids at atmospheric pressure

of sfight variations in iron oxidation state. Ferrous iron values were determined by a volumetric titration technique (WILSON, 1960). Modifications to the method involved changes in reagent concentrations and consistent use of approximately 2Omg of sampie for each analysis. Ammonium vanadate (0.0139N) and ammonium ferrous sulphate (0.00695N) were added using a Metrohm E457 micro-burette. which had a measured reproducibility of kO.005 ml. Canadian reference materials SY2 and MRGI (ABBEY. 1976) were analyzed with each batch of samples. An average ratio of recommended vs measured Fe0 values for the reference materials wa{ applied as a correction factor to Fe0 in the samples because of small but consistent differences between batches. The uncorrected and corrected wt”/‘, Fe0 values and also the mean and standard deviation for the reference materiab are presented in Table 1. Thirteen determinatjons of wt?‘, Fe0 in the unheated 401 diabase were made by this procedure. These analyses. which were spread throughout five sample batches. ranged from 9.52 to 9.91 wt% FeO, and had a mean of 9.74 and standard deviation of 0.17. In the majoritj of cases, samples were analyzed in duplicate. The standard deviation of the 56 duplicate sample analyses was calculated to be 0.11 wt”,; over the range 6.61-10.68 wt:, FeO. Total iron was analyzed with other major elements by means of an ARL-AMX electron microprobe with an energy dispersive detector. Ferric iron was determined by the difference between total iron and ferrous iron. All analyses were conducted at I5 kV and a beam current off 0.35-0.45 x lo-’ A. Total iron analyses proved to be the greatest source of variance of the ferric-ferrous ratio due to an average iron heterogenelty of up to 0.5 wt?; per three analyses of glass in each run. Potassium addition to basaltic starting material

resulted in crystallization of olivine at 1200°C or, from extremely potassic melts, sanidine plus olivine. Likewise, at 1200°C all melts enriched in aluminum contained crystals of plagioclase and hercynitic spinel. In those runs containing crystals, the wet chemical value for ferrous iron was corrected to obtain the weight fraction of ferrous oxide in the liquid, considering volume, density and iron concentration in all phases concerned. RESULTS In order of decreasing significance, the addition of oxides of potassium, sodium, aluminum, silicon and calcium. produce an increase in the ferric iron concentration of the melt at 120DcC. The effect of each of these major components on the ferric-ferrous ratio in the liquid is considerably less at 1360°C than at 1200°C. Figure 2 (a-j) shows the change in the ferricferrous ratio per mol% added oxide in the liquid of each run series. Ferric and ferrous iron variation is presented as the ratio of moi% FeOls to molS; Fe0 and all melt components are treated as molld single cationic oxides (e.g. Na00.5r Si02). Variation bars in each diagram represent the maximum difference in ferric/ferrous values for each run and are primarily attributable to iron heterogeneity in the glass as determined by electron microprobe analysis. Best fit lines in each diagram were calculated by least squares regression analysis of the data points and the degree of linear correlation is represented by the correlation coefficient (cc). Comparison of data at 1200°C with that at 1360°C indicates that the effect of increased temperature is to reduce the effect of composition upon ferric-ferrous ratio changes in the melt. Furthermore, it appears that aikalis and lime have a greater effect on the ratio at higher temperature. relative to alumina and silica. P s Zi t

0.d 0

’ 2

8

4 MOLE

’ 6 PERCENT

’ 8 ROM

’ 10

L

J 12

If-4 LlQUfD

kg. 2c

0.

1200-C

a

lo-8

ZlI

atm 102

527

SLOPE = o.otr CL s 0.70

2(aii).

Pig. 2b o.soo

l%o‘C

0.loot

lO+olmfO,

528

R.

C.

P. L.

THORNBER.

and J. R. FOSTER

ROEDER

Fig. 2h

4& MOLE FERCENT

Sro,

4%

52

50

MOLE

IN LIQUID

54

56

58

PERCENT S102 IN LIQUIO

Fig. 2i

SLOPE so.009 cc= 0.89

0.500

1200x

0.400

10-e atm fC&

0.

1

oocd

.

8

Fig.

I

IO

1

t

12

1

14

16

MOLE

PERCENT

.

.

CA0

*

1

I

18

20

.

I

22

.

8

,

24

IN LtQUID

2j

0.

0.

136Dz 10e6 atm fg2

Fig. 2a-j. Ferric-ferrous ratio variation with molqb oxides added to 401 (i.e. KOo.os, NaOos, Si02, A101.5, and CaOl at 1200 and 1360°C. Open circles represent runs of ‘undoped’ 401 starting material. ‘cc’ is the correlation

coefficient

of least squares

DISCUSSION The pronounced effect of alkalies (the ‘alkali effect’ of CARMICHAEL et al.,1974) in controlling the ratio of ferric to ferrous iron in the 401 basaltic liquids is analogous to results of investigations of multivalent cation ratio variations in simple, synthetic glasses (PAUL and DOUGLAS, 1965a,b; NATH and DOUGLAS, 1965; PAUL and LAHIRI, 1966). According to these studies, iron, cerium, chromium and manganese are oxidized as a function of bulk alkali enrichment and,

regression

analysis

of the data

points.

in accordance with our data, highest oxidation ratios are invariably attributed to potassium-enriched glasses. Using data of the FUDALI (1965) investigation of ferric-ferrous iron equilibrium for a variety of natural compositions. CARMICHAELer al. (1974) point out that ferric iron concentration increases as percent normative feldspar increases. indicating that alkalies, and alumina and silica may significantly contribute to fixing the redox state of the melt. This implication is confirmed by experimental results of the present study.

Ferric-ferrous

ratio in basaltic liquids at atmospheric pressure

SCHREIBER (1977) presents data on the differences in Cr3+Crz+ and TiJ+,Ti3+ ratios of two, iron-free, model basalt compositions at 1500°C and indicated that enrichment of CaO in the melt enhanced oxidation of these species to a greater extent than alumina enrichment. These data are in agreement with relative differences in the Fe3+/FeZ+ ratio produced by addition of lime and alumina to 401 at a temperature well above the liquidus (1360°C) ‘(see Figs 2f and j). At present. there are no comprehensive data regarding the effect of individual components of natural melts on the valence states of chromium and titanium at lower f02 values typical of the lunar environment. However. in light of the analogous compositional dependence of the oxidation state of iron and other multivalent elements. it is probable that changes in Cr3+Cr2+ and Ti4+:Ti3’ ratios in lunar basaltic liquids are affected by composition in a similar manner. Systematic variation of oxidation ratios with composition in melts equilibrated at identical conditions of P. T and f02. imply that chemical reactions involving discrete melt components define redox equilibria. Continued investigation of compositional effects on oxidation ratios will provide not only information pertaining to the oxygen buffering capacities of magmas. but also a basis for more accurate models of the actual structural entities (i.e. complex anions or polymers) involved in specific redox reactions.

Acknowledgements-Critical

reviews of this paper by R.

WENDLANDT.B. LIPIN. G. CZAMANSKE.M. SATO and H.

WAFF. are gratefully acknowledged.

REFERENCES ABBEYS. (1976) Report on the collaborative analysis of three Canadian rock samples for use as certified reference materials. Supplement 1. Canadian Met. Report 76-36. Printing and Publishing Supply Services. CARMICHAELI. S. E.. TURNER F. J. and VERH~~GENJ. (1974) Igneous Petrolog.r. 739 pp. McGraw-Hill. DONALDSON C. H.. WILLIAMSR. J. and LOFGRENG. (1975)

(APPENDIX--see

529

A sample holding technique for study of crystal growth in silicate melts. Am. Mineral. 60. 324-326. DRICKAMERH. G.. LEVK~S Ci. K. JR and FUNG S. C. (1969) The oxidation state of iron at high pressure. Science 163. 885-890. EUGSTERH. P. and WONESD. R. (1962) Stability relations of the ferruginous biotite. annite. J. Petrol. 3. 82-125. FUDALI R. F. (1965) Oxygen fugacities of basaltic and andesitic magmas. Geochim. Cosmockim. Acta 29, 1063-1075.

HAGGERTYS. E (1976) Opaque mineral oxides m terrestrial igneous rocks. In O.xide Minerals (ed. D. Rumble III) Mineral. Sot. Am. Short Course Notes, Vol. 3, Chap. 8. pp. 101-l 76. Southern Printing Co. HAUGHTOKD. R.. ROEDERP. L. and SKINNERB. J. (1974) Solubility of sulfur in mafic magmas. &on. Geol. 69, 451-467. HILL R. E. T, (1969) The crystallization of basaltic melts as a function of oxygen fugacity. Ph.D. Thesis. Queen’s University. HILL R. and ROEDERP (1974) The crystallization of spine1 from basalttc liquid as a function of oxygen fugacity. J. Geol. 82. 709-729. KENNEDYG. C. (1948) Equilibrium between volatiles and iron oxides in igneous rocks. Am. J. Sci. 246. 529-549. MYSENB. 0. and VIRGO D. (1978) Influence of pressure, temperature and bulk composition on melt structures m the system NaAlSi,06-NaFe3+ Si,O,. Am. J. Sci. 278, 1907-l 322. NATH P. and DOUGLASR. W. (1965) Cr3+-Cr6+ equilibrium in binary alkali silicate glasses. Phys. Chem. Glasses 6, 197-202. PAUL A. and DOUGLASR. W. (1965s) Ferrous-ferric equilibrium in binary alkali silicate glasses. Phys. Chem. Glasses 6, 207-2 11. PAULA. and DOUGLASR. W. (1965b) Cerous-ceric equilibrium in binary alkali borate and alkali silicate glasses. Phys. Chem. Glasses 6. 212-215. PAULA. and LAHIRID. (1966) Manganous-manganic equilibrium in alkali borate glasses. J. Am. Ceram. Sot. 49, 565-567. SCHREIBER H. D. (1977) Redox states of Ti. Zr, Hf, Cr and Eu in basaltic magmas: an experimental study. Proc. 8th Lunar Sci. Cor$ pp. 1785-1807. THORNBERC. R. (1977) Factors controlling the ferricferrous ratio in basaltic liquids. MSc. Thesis. Queen’s University. WAFF H. S. (1977) The structural role of ferric iron in silicate melts. Can. Mineral. 15, 198-199. WILSONA. D. (1960) The micro-determination of ferrous iron in silicate minerals by a volumetric and a colorimetric method. Anol?;sr 85, 823-827.

next page)

C. R. THORNBER. P. L. ROEDERand J. R. FOSTER

530

APPENDIX Composition

and run data Table A. 401 Diabase

Run No. femp (“C)

54 1200

61 1200

Time (hrs.)

29.:

29.:

COZIHZ 109 fo D

Liq. Alp. Na20 M90 Al 203 Si02 K20 CaO Ti02 MnO Fe0

52 1200

14.5

118 1355

98

13lyg

142 1363

16.3

4.5

22.5

i2.5

29.0 -8.03

28.3 -6.11

28.3 -6.15

28.3 -6.07

3.12 6.62 15.34 49.68 0.89 a. 73 1.73 0.18 12.09 98.38 10.68 -+o. 02

-8.03

-8.03

29.0 -8.03

2.99 6.67 15.48 49.45 0.83 8.49 1.78 0.23 12.55

2.92 6.56 15.40 49.33 0.90 8.80 1.89 0.14 12.39

3.25 6.74 15.30 49.47 0.77 8.67 2.10 0.18 12.35

3.11 6.62 15.58 49.70 0.87 a. 74 1.90 0.00 12.33

2.70 6.57 15.04 49.33 0.81 a.95 0.19 12.42

2.80 6.68 l5.16 49.64 0.80 a. 87 1.98 0.18 12.48

98.47 il.01 LO.04

98.33 10.60 20.20

98.83 11.12 +0.09

98.85 10.88 zo.09

97.84 10.03 +o. 05

98.59 9.98 -+o. 14

0.133

0.238

0,250

0.132

100% L

100% L

100% L

100% L

(wt.%)

Total Fe0 ( wet them.) MO;;;

51 1200

1.83

kc$_’

Phases jVo1 umel)

0.140

0.168

0.110

100% L

100% L

100% L

Table B. Potassium addition runs Run No. Temp. (“C) Time (hrs.) CO2/‘H2 109 fo 3

401 Kl 70 1202 17.5 29.0 -8.01

401 Kl 71

401 Kl

401 Kl 77 1203

401 K2 74 1203

401 Kl 72 34203 5 2813 -8.03

2;:; -8.00

29.1: -8.00

29,; -8.00

401 K2 125 1205 18.5 28.3 -8.00

::03

NaiO MgO A’203 Si02 K20 CaO Ti02 MnO Fe0

’ 3.07 5.84 15.09 47.99 4.75 8.28 1.96 0.28 11.07

3.08 5.61 15.18 47.73 4,76 8.60 1.79 0.17 11.63

2.97 6.16 15.44 47.94 4.56 8.58 1.87 0.08 12.00

3.03 5.45 15.10 47.57 4.70 8.69 1.93 0.19 11.71

2.72 5.81 15.02 47.61 4.82 8.29 1.70 II.28 II.87

3.46 5.90 12.92 44.43 5.69 10.19 2.14 0.14 13.62

2.59 6.27 12.96 44.86 6.19 9.78 2.06 0.27 13.47

Total Fe0 (wet them.)

98.33 9.47 +0.16 -8.80

98.55 . +0.09 -8.95

99.60 10.03 +o. 06 -9.40

98.37 9.98 +O. 58 -9.10

98.12 9 ‘1 +0:;7 -9.09

98.49 9.29 +0.01 io.47

98.45 9.iO 10.20

0.257 95 5PO:

0.299 93% 7% 0:

0.276 95% L 5% 01

0.286 93% L 7x. ‘)1

0.305 95% 5x 0:

0.300 70% L 20% Sa 10% 01

0.320 70% L 20% Sa 10%

Fe0 in Liq. ~ (Volume I)

oi

Ferric-ferrous Table Run No. Temp (“C)

ratio in basaltic B. Potassium

401 K2 135 96

Fe0 in Liq. Mol eX Fe01 Mole% Fe0 Phases (Volume X)

98.67 9.60 +0.07 io.93 0.221 7O?iL

runs (continued) 401 K2 111 1363

401 Kl 121 1359

401 K2 22 1359

401 K5 131 1366

28.: -6.11

20.3 20 -6.07

28.3 19 -6.11

28.43 -6.02

2.75 6.41 14.62 47.58 4.4% 8.41 1.77 0.12 11.84

2.51 6.49 14.79 47.74 4.50 a.48 1.99 0.0% 11.82

1.83 6.40 14.64 47.60 5.9% 8.10 1.60 0.20 11.16

2.01 6.4% 14.51 47.41 6.2% 8.39 1.79 0.16 11.61

2.52 6.30 14.09 45.52 7.63 8.00 I?:‘! 11.72

97.98 9.40 +0.08 -

98.40 . ~0.06

97.51 8.92 -+0.15

98.64 . ‘0.10

97.77 9.11 zo.02

0.259 1007xL

0.237 100% L

0.251 100% L

0.300 100% L

C. Sodium

ad&Ion

0.286 100% L

runs

401 Nal 401 Nal 401 Nal 401 Nal 401 Nal 401 Na2 401 Na2 58 63 64 53 55 56 57 1200 1206 1200 1200 :7.: 20 1197 1199 7 7 17.5 17.5 23 17 29.0 29.0 28.3 29.0 29.0 28.3 28.3 -8.03. -:7.9% -8.05 -8.03 -8.01 -8.09 -8.08

(wt.%)

“._)

Total Fe0 (wet

531

c,

1

Liq. C:mp. Na20 M90 A101.5 SiO7 KOn-& CaO Ti02 MnO Fe0

pressure

28.3 5.5 -6.07

Table Run No. Temp (“Cj Time (hrs. C02/H; 109 f0"

addition

401 Kl 110 1363

C02/H2(hrs.) 20.3 Time ::.5 lo9 fo -8.09 2 Liq. Comp. (wt.%) Na20 3.05 W’ 6.16 A’ 203 12.86 Si02 44.8% K2O 5.76 CaO 10.14 Ti02 2.2% MnO 0.19 Fe0 13.35 Total Fe0 ( wet them.)

liquids at atmospheric

them.)

Mole% FeOl_5 Mole% Fe0

3.98 6.59 15.40 49.71 0.87 8.5% 1.82 0.13 11.46

5.53 6.53 15.18 4%. 42 0.85 8.56 1.74 0.06 11.84

5.60 6.56 14.94 48.51 0.70 8.4% 1.82 0.26 11.85

5.85 6.4% 14.93 4%. 20 0.85 8.44 1.82 0.12 11.5%

5.45 6.15 14.74 47.12 0. a2 8.61 1.95 0.22 12.32

7.71 6.58 14.78 4%. 06

98.54 10.6% -to.06

98.71 10.36 LO.04

98.72 10.22 to. 01

98.27 10.20 to.06

0.072

0.143

0.159

100% L

100% L

100% L

7.93 6.73 14.65 47.40

0.79

0.77

8.36 1.69 0.01 11.92

8.18 1.78 0.2% 11.79

97.3% 10.08 +o.oz

99.90 9.51 zo.03

99.51 9.61 20.05

0.119

0.221

0.253

0.183

100% L

100% L

100% L

100% L

Phacnc ..W__”

(Volume%)

Table Run No. Temp (“C) Time (hrs.) CO2/H2 lo9 fo ? Liq. CLmp. (wt.%) Na20 M90 A’ 203 siop K20 CaO Ti02 MnO Fe0 Total Fe0 (wet

them.)

Mole% Fe01.5 Mole% Feo Phase< (Vol ume”b)

C. Sodium

401 Na2 67 1200 29.: -8.03

addition

runs (continued)

401 Na2 401 Na3 401 Nal 401 Na2 401 Na2 401 ‘Na2 6% 147 120 129 139 119 1200 1200 356 1360 1364 1360 :7.5 4 7 5.3 5.5 2%. 3 28.3 28.43 28.3 28.3 2%. 3 -6. i4 -6.10 -6.05 -8.05 -8.05 -6.10

5.55 6.42 14.87 47.96 0.62 8.53 1.74 0.23 11.23

6.77 6.32 14.60 47.01 Z 1.83 0.12 11.63

6.96 6.10 15.11 47.84 0.79 0.32 1.59 0.19 11.02

97.15

LO.12

97.29 a.99 +o. 13

97.92 a.82 TO.01

0.284

0.245

0.293

0.249

100% L

100% L

100% L

100% L

a. 50 6.54 14.67 47.66 0.84 8.24 1.78 0.07 11.51

8.2% 6.43 14.76 46.8% 0.89

99.81 9.42 LO.05

99.30 8.89 +0.03

+0.04

LO.05

0.222

0.323

0.22%

100% L

100% L

100% L

8.17 1.85 0.2% 11.76

7.87 6.24 14.3% 46.05 0.87 8.20 1.64 0.12 12.00

4.84 6.53 14.66 48.03 0.83 8.36 1.91 0.14 12.10

97.37

97.40

9.77

9.42

9.02

C.

532

R.

THORNBER,P. L. ROEDERand J. R. FOSTER Table D. Aluminum addition runs

Run No. Temp (“C) Time (hrs.) C02/H2 lo9 fo 2 Liq. Comp. Na20 M90 Al 203 Si02 K20 CaO Ti02 MnO Fe0

401 All 104 1197 8 29.0 -8.05

401 All 134 1195 5.5 28.3 -8.10

2.88 6.44 17.81 47.27 0.90 7.88 2.01 0.19 12.19

Total

97.57

Fe0 (wet them.)

. 9

(Vol umeX)

-8.00

401 A12 401 Al2 149 150 1200 1200 18 6 28.3 28.3 -8.05 -8.05

401 All 102 1359 6 28.3 -6.11

2.98 6.75 17.16 47.48 0.82 8.15 1.88 0.03 12.67

2.64 6.06 19.32 46.52 0.83 7.35 2.10 0.26 12.82

2.75 6.18 28.68 46.68 1.01 6.85 2.10 0.29 13.13

2.70 5.99 18.34 45.72 0.98 6.83 2.26 0.33 12.96

97.92

97.90

97.67

96.11

9 69

10.09

20.00

LO.09

0.196 L

-0.190 L

i.2,:

0.23;

0.098

3% sp 2% PI

3% sp 2% Pl

30% sp 30% Pl

30% sp 30% Pl

25% Sp 25% Pl

401 Sil 114 1207

E.

-6.07

108 1363 19 28.3 -6.07

AlZ 130 135917.5 28.3 -6.11

2.62 6.53 20.32 46.96 0.71 8.36 1.67 0.16 9.79

2.59 6.49 20.49 46.74 0.78 8.31 1.72 0.34 11.24

2.57 6.14 25.08 44.93 0.71 7.92 1.69 0.05 10.18

2.53 5.92 24.50 43.35 0.72 7.80 1.57 a. 26 10.78

97.12

98.70

99.27

97.43

8.63

9.61 to.02

8.65 to.03

9.36 20.06

9.96

to:01

Table Run No. Temp (“C) Time (hrs.) CO2/H2 109 fo_

9.53

to.04

LO.01 w P

401 A12 126 1205 28.:

401 Al2 401

401 All 103 1363 2813

0.;“:

“.;6;

l&7;

0.15;

Silicon addition runs

401 Sil 112 1207 20 29.0 -7.97

401 Sil 146 1196

292: -7.97

28:: -8.10

29203 -8.03

281: -8.09

28:: -6.07

28.5 -6.10

2823” -6.08

401 Si2 132 1363 19.3 28.3 -6.07

Liq. Ccdnp. (wt.%) Na20 M90 Al $ 3 Si 2 K20 CaO Ti02 MnO Fe0

2.85 6.12 14.40 55.02 0.78 8.03 1.59 0.16 10.17

2.23 5.70 13.25 56.83 0.62 7.64 1.59 0.15 10.92

2.71 6.35 13.89 53.12 0.85 8.19 1.66 0.22 12.06

2.38 5.95 12.90 57.84 0.64 7.40 1.66 0.08 11.15

2.38 5.62 12.63 56.99 0.70 7.37 1.40 0.23 10.35

2.38 6.43 13.79 53.98 0.81 8.03 1.77 0.17 11.06

2.62 6.45 13.87 53.44 0.79 8.14 1.64 0.27 11.76

2.31 5.33 12.67 58.68 0.71 7.14 1.38 0.21 9.61

2.23 5.51 12.43 57.68 0.66 7.48 1.52 0.00 10.01

Total ? 0 (wet

99.12 8 88

98.93 8 *36

99.05 $12 0 18

99.64

97.68

98.42 8.72 ~0.16

99.04 9.69 ~0.10

98.04 8.10 20.04

97.52 8.62 LO.04

go1 0.145

LO.02 0.305

0.184

LO.17 0.242

LO.09 0.182

0.268

0.213

0.185

0.163

100% L

100% L

100% L

100% L

100% L

100% L

100% L

401 Cal 95 1205

401 Ca2 96 1205

401 Sil 116 1200

401 Si2 137 1198

401 Sil 113 1363

401 Sil 138 1360

401 Si2 117 1362

z

them.)

&W (Vol ume%)

.

.

100% L

100% L

Table F. Calcium addition runs Run No. Temp (“C) Time (hrs.) CO2/H2 lo9 fo ^

401 Ca2+ 148 1200

29.: -7.99

29:: -7.99

28:: -8.05

401 Ca3 401 Cd3 401 Cal 401 Ca2 401 Ca3 401 Ca3 40‘1 Ca3 124 133 105 109 123 129 141 1207 1211 1363 1363 1357 1359 1363 7 7.5 24.3 28.3 28:: 28.: 28:: 28.3 28.3 248:: -7.99 -7.94 -6.07 -6.07 -6.13 -6.11 -6.07

2.07 6.46 14.92 48.26 0.87 11.56 1.77 0.17 11.56

2.91 6.70 14.71 47.78 0.80 11.39 1.81 0.13 11.94

2.62 6.14 14.20 46.45 0.83 14.33 1.69 0.10 11.53

2.40 5.72 13.31 41.93 0.70 23.82 1.61 0.10 10.14

2.40 5.70 12.85 41.46 0.59 23.40 1.72 0.12 10.16

2.72 6.72 14.80 48.28 0.80 11.62 1.86 0.23 11.75

2.31 6.35 15.25 47.98 0.71 11.67 1.74 0.18 11.61

1.57 6.02 13.08 42.25 0.33 24.07 1.66 0.07 9.95

1.13 5.72 13.48 42.14 0.23 24.25 1.58 0.19 9.65

1.85 5.46 12.88 41.72 0.62 23.92 1.45 0.25 10.11

97.64 +0:03 9 75

98.17 20.16 9.93

97.89 20.02 lo:06

99.73 7.73 ‘.I0

98.40 8.10

98.78 9.66 ‘.I0

97.80 9.70 +o. 11 -

99.00 6.76 to.03

98.37 7.87 -+0.04

98.26 . 0.05

0.185

0.202

0.146

0.311

0.254

0.216

0.196

0.474

0.226

0.292

100% L

100% L

100% L

100% L

100% L

100% L

100% L

100% L

100% L

100% L

L

1‘

. camp.

$0 WJ A’ 3 Si ;i”2 K20 CaO TiOp MnO Fe0 Total

(Vol urn&)

wt.