541.12 : 541.13

REGIONS OF REACTION. X '). THE REACTION REGIONS Fe-S-SiO, Pc-Mg-S

and Fe-Al-S BY

W. P. JORISSEN AND B. L. ONGKIEHONG.

It is wellknown that a reaction, started locally in a mixture of solid substances, may propagate itself through the whole mass, if the composition of the mixture is suitable. W e have only to call to mind gun powder, made from charcoal, sulphur and salpetre, and the different mixtures in fireworks. As lecture experiments there may be cited the propagation of the reaction in mixtures of iron and sulphur, of magnesium and silica and such like.

The importance of the study of such reactions has become obvious since Hans Goldschmidt z, applied the aluminothermic reduction to his "thermites". When we read W. Prandtl's "Thermitreaktionen" 3, we get an impression of the great variety of the reactions taking place in an analogous way.

The reaction region, however, has not been investigated till now in any of these cases.

The following experiments will show that, using mixtures of solid substances, we may find reaction regions which resemble those ob-

I) The 9 previous communications have appeared under the titles: O n the influence of noninflammable vapours ,of organic liquids on the limits of inflammability of methane air mixtures, I. (with J. Velisek. Rec. trav. chim. 43. 80 (1924)) ; 11 (with J. C. Meuwisscn, Ibid. i3. 591 (1924)) ; The influence of some noninflammable vapours of organic liquids on the limits of inflammability of mixtures of inflammable gases and air 111 (with J. C. Meuwissen. Ibid. 44, 132 (1925)): 1V. The influence of dichloro- and trichloro- ethylene on the limits of inflammability of carbon monoxide-air mixtures (with J. H. A. P. Langen van der Valk. Ibid. 4i, 810 (1925)): V. The influence oftrichloro- ethylene on the limits of inflammability of hydrogen-air mixtures (with B. L. Ongkiehong, Ibid. 44, 814 (1925)) ; L'influence que des gaz et des vapeurs. inflammables ou non, exercent sur les limites d'explosibilttk de melanges de gaz et d'air VI: La reprhentation graphique. Ibid. 44, 1039 (1925) ; Domaines d'explosion VII : L'influence de I'&hylene sur les limites d'explosion du gaz tonnant (with B. L. Ongkiehong. Ibid. 45, 162 (1926)) ; Explosion regions Vlll: The explosion regions of hydrogen-ammonia- air and hydrcgen-ammonia-oxygen mixtures (with B. L. Ongkiehong, Ibid. 45,224 (1926)) : Explosion regions IX: The explosion space C,HjBr-NHa--O,-N, (with B. L. Ongkiehong, Ibid. 45, 400 (1926)).

*) 2. Elektrochem. 4, 494 (1897). 6. 53 (1899); Ann. 301, 19 (1898); 2. angew. Chem. 1898, 821 : J. Soc. Chem. Ind. 17, 543 (1898).

3, Stabler's Handbuch d. Arbeitsmethoden in der anorgan. Chem. IV 2, 315 (1926).

.

54 1

served by us with gaseous mixtures ').

T h e r e a c t i o n r e g i o n Fe-S-SiO,. The iron powder used was ferrum pulverat. Ph. Ned. IV; the sulphur was pulverized roll sulphur : the silica powder was prepared from precipitated silicic acid by heating this to constant weight. All three powders had been sieved by means of a copper gauze having 9 holes per mm'. The mixtures were carefully made from weighed quantities. They were fired by means of a mixture of 56 parts of iron and 32 parts of sulphur to which a small flame was applied.

The experiments were made using glass tubes (length 10 cm., diameter 0.75 cm.), closed at one end. They were laid on asbestos board and surrounded by metal gauze.

Mixtures of iron and sulphur: no reaction with 46 Ole, 48 (2 exps.), 49 o / o (2 exps.) and 50 O Fe (2d exp. : propagation 2-3 cm.), reaction with 51 O o , 52 o / o . 75 Ole, 80 o / o and 84 Ole, but not with 85 O o, 86O/, and 90' Fe. Lower reaction limit: 50.5 o / o Fe and 49.5 " S; upper reaction limit 84.5 o / o Fe and 15.5 S.

Mixtures of iron. sulphur and silicon dioxide. 10 SiO,: No reaction with 49 and 50 Fe, reaction with

51 O o , 52O o , 6 0 ° o , 68'10 and 69 o , o Fe, but not with 70°i0 Fe (2 exps.). Lower reaction limit : 10 SiO,. 50.5 Fe and 39.5 S; upper reaction limit: 10 o / o SiO,, 69.5 O l 0 Fe and 20.5 O l 0 S.

SiO, : No reaction with 50 Ol0 and 51 o:o Fe, reaction with 52 O o , 53 Ole, 54 O o , 60 Ole, 62 and 63 o / o Fe (2 exps.), but not with 64 O l 0 and 65 o / o Fe. Lower reaction limit: 15 O i 0 SiO,, 51.5 o!o Fe and 33.5 O ,, S; upper reaction limit: 15 o / o SiO,. 63.5 o / o Fe and 2 1 S o j 0 S.

18 O SiO,: Reaction with 57 O l 0 and 59 o / o Fe, but not with 60 O/, Fe. Upper reaction limit: 18 O,l0 SiO,, 59.5 Oilo Fe and 22.5 S.

19 Ol0 SiO,: Reaction with 54 o / o , 55 Ole, 56 20 " i0 SiO,: No reaction with 54 Ole, reaction with 55 Ole. but

21 O l 0 SiO, : No reaction with 53 O o , 54 ' l o , 55 o / o . 56 and

The top of the curve (see fig. 1 ) is thus to be found at about

15 O

and 57 O l 0 Fe.

not with 56°/0 Fe.

57 '' Fe.

20 O l 0 SiO,. 55 o / o Fe and 25 O S .

SlOZ

Fc

: I , , , ,

S 10 20 3 0 4 0 5 0 6 0 7 0 8 0

Fig. 1. Rcnccton rcg,on Fc-S--&a. ---

') See foot-note I .

542

The reaction region resembles those observed with mixtures of CH,, air and CCl, 7. CO, air and C,HCI, e), CO, air and CHCI, ').

T h e r e a c t i o n r e g i o n Fe, Mg a n d S. The reaction limits of iron with sulphur have been given above.

Mixtures of magnesium and sulphur. No reaction with 20 Ole, 22 and 23 O l 0 Mg, reaction with 24 o:o. 26 O o , 30 o ; o . 43 Ole. 67 o;o. 80 Ole. 82 O l 0 and 83 o , o , but not with 84 O l 0 (2 exps.) and 90 Ole. Lower reaction limit: 23.5 o / o Mg and 76.5 o/o S; upper reaction limit: 83.5 Mg and 16.5 O S.

Mixtures of iron, magnesium and sulphur. 10 O/,, Fe: No reaction with 15 o , o and 17 Mg, reaction with

18 Ole, 19°/o. 71 and 72 O l 0 Mg. but not with 73 O o, 74 O and 75 Mg. Lower reaction limit: 10 Fe, 17.5 Mg and 72.5 S; upper reaction limit: loo:, Fe, 72S0 Mg and 17.5OiO S.

30 O1, Fe: No reaction with 8 Ole, 9 Ole, 10 " ' o (2 exps.). 11 O (2 exps.) and 12°/0 Mg, reaction with 13OiO and 14°/o Mg. Lower reaction limit: 30 o / o Fe, 12.5 Mg and 57.5 S. 40 Fe: No reaction with 6 o/o, 7 Ole. 8 Ole, 9 O (2 exps.) and

10 Ol0 (2 exps.), reaction with 11 Oi0, 12 Ole, 45 Ol0 and 46 O l 0 (2 exps.), but not with 47 o/o (2 exps.) and 48 Mg. Lower reaction limit: 40 Fe, 10.5 o ' o Mg. and 49.5 o/o S; upper reaction limit: 40 Fe, 46.5 O l 0 Mg and 13.5 S.

Mg

50 .

4 0 -

3 0 -

Pe 10 20 30 40 50 60 70 80

Fig. 2. Reaction region Pc-Mg-S.

') Rec. trav. chim. 53, 593 (1924): Meuwissen O) Ibid. 44, 813 (1925): Langen van der Valk ') Chem. Weekblad 23. 80 (1926). fig. 9 : Chem. News 132, 151 (1926). fig IX:

Langen van der Valk.

543

56" Fe: Reaction with 29 O and 30" Mg (2 exps.), but not with 31 o!o and 32 O

Mg and 13.5 S.

not with 14 " i 0 , 18 O

13.5 "io Mg and 16.5 O i 0 S.

Mg. Upper reaction limit: 56 n!o Fe, 30.5

70 '' Fe: Reaction with 10 "i0, 11 O ! " . 12 O and 13 O Mg. but and 20 ' / o Mg. Upper reaction limit: 70 o/o Fe,

The reaction region is represented in fig. 2. It resembles that observed with gas mixtures of, for example,

C,H,, H, and oxygen ') and of H,, NH, and oxygen 9).

T h e r e a c t i o n r e g i o n Fe, A1 a n d S. The reaction limits of iron with sulphur have been mentioned

above. Mixtures of aluminium and sulphur alone could not be made to react by means of the firing mixture 1 Fe + 1 S.

As it is wellknown that a more powerful firing mixture is able to start a reaction between aluminium and sulphur, we expected a reaction region Fe- Al-S resembling that of NH,-H,-air lo) and of CO-CH,Cl,-air ' I ) .

Mixtures of iron, aluminium and sulphur. 10" Al: N o reaction with 40" and 41 "in Fe, reaction with

42 'I (2 exps.) and 45 ' 1 , (2 exps.), 70 O i 0 and 71 " /o Fe, but not with 72 "i l l . 75 "/, and 78 O / , , Fe. Lower reaction limit: 10 'lo Al, 41.5 Fe and 48.5 O S; upper reaction limit: I0 " ' ' Al, 71.5 "i0 Fe and 18.5 " : 0 S.

15 ' j o Al: No reaction with 38 ,, and 39 Fe, reaction with 40 o i ," and 41 and 65 u / o Fe (2 exps.), not with 66 'lo, 67 O i 0 and 68 o ' o Fe. Lower reaction limit: 15 O i 0 Al. 39.5'!:, Fe and 45.5 Al, 65.5 Oi0 Fe and 19.5 o/o S.

20°;, Al: No reaction with 34O/, and 36°/0 Fe, reaction with 37 Ole, 38 o/o (2 exps.), 40 (2 exps.) and 60 "!,, Fe (2 exps.), but not with 61 "/,. 62 O f, and 64 "/,, Fe. Lower reaction limit: 20 "!,, Al, 36.5 S ; upper reaction limit: 20 " ll Al, 60.5 Fe and 19.5 I ' ,, S.

Fe, reaction with 33 o,,o (2 exps.), 34 'I Fe (2 exps.). but not with 43 O:o and 44 Fe. Lower reaction limit: 35 "in Al, 32.5 ",', Fe and 32.5 (I/,, S; upper reaction limit: 35 ' j , , Al, 42.5

38 Al: N o reaction with 35" and 36 ",',, Fe, reaction with 37 (2 exps.), but not with 38 " Fe.

39 ' fl Al: No reaction with 34 O i 0 and 35 "/11 Fe. The reaction region is represented in fig. 3. W e see that it tries

(2 exps.), 62 O

S; upper reaction limit: 15 O

50

Fe and 43.5

35 ' I A1 : No reaction with 32 37 "I,, (2 exps.), 40 " , I and 42

Fe and 22.5 S.

to reach the S - Al axis. - ....

$) Rec. trav. chim. 45, 162 (1926): Ongkiehong. ') Ibid. 45. 224 (1926): Ongkiehong.

I") Rec. trav. chim. 45, 227 (1926): Ongkiehong. l ' ) Chem. Weekblad 23, 80 (1926). fig. 9 ; Chem. News 132, 151 (1926). fig. IX:

Langen van der Valk.

544

This research (which has been supported by the Hoogewerff-Fonds) Al

Fig. 3. Reaction region Fe- AI-S.

has resulted in the finding of the three principal types of reaction regions.

Other systems, in which we may expect special cases to appear, will now be investigated ”). W e also intend to determine the reaction velocity in different parts of the reaction regions.

L e i d e n , The University. Inorganic Chemistry Laboratory, June 1926.

( R e p le 15 juin 1926).

11) See also Chem. Weekblad 23. 79 (1926): Chem. News 132, 149 11926).