THE SYSTEM, MAGNESIUM-OXIDE--BORIC-OXIDE

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D O C T O R A L D I S S E R T A T I O N SERIES

Ttje. System, Magnesium Oxide-Boric Oxide

TITLE

AUTHOR

M ellen A u b rey K n ig h t

UNIVERSITY. DEGREE_

DATE

Aug. I$42

Tbmsylvdnid Sidit College

EbJX.

_

PUBLICATION NO. pi1 ijijiji i|i|i|i ij>i|i|i , T fi

UNIVERSITY MICROFILMS /M

ANN

ARBOR

■

MICHIGAN

The P e n n s y lv a n ia S t a t e C o lle g e The G raduate S c h o o l D epartm ent o f C eram ics

The S y stem , Magnesium O xide - B o r ic O xide

A T h e s is by M ellen A ubrey K n ight

S u b m itte d in p a r t ia l, f u l f i l l m e n t o f t h e req u ir e m e n ts f o r th e d e g r e e o f D o c to r o f P h ilo s o p h y

A u g u st, 1942 Approved A ugust 2 0 , 1942 Head o f th e D epartm ent

T a b le o f C o n ten ts

P age, la I.I a

III.

STATEMENT OF PROBLEM

1

HISTORICAL

2

A*

MATERIALS

2

1.

B o r ic O xide:

2

2„

Magnesium O x id e:

2

B.

SYNTHESIS OF BATCHES

5

C,

CHEMICAL ANALYSIS

7

D,

THERMAL ANALYSIS

E.

PETROGRAPHIC EXAMINATION

9

Fe

MIXTURES OF B2 0 ? AND MgO

10

_

8

APPARATUS

13

A.

GAS FURNACES

13

B9

CASCADE FURNACE

15

1.

C o n s tr u c tio n :

15

2e

Tem perature M easurem ent:

15

a® T h erm o elem en ts-

16

bo

C a lib r a t io n o f T h erm o co u p les-

17

c®

E l e c t r i c a l I n str u m e n ts—

20

d6

T em perature M easu ring C ir c u it —

20

3»

4,e

IV.

Tem perature C o n tr o l:

21

a®

C u rren t C o n tr o l”

21

b®

C o n sta n t T em perature C o n tro l A p p a r a tu s-

21

Co

H e a tin g Curve Tem perature C o n t r o l-

22

W iring D iagram F or C ascade Furnace

22

EXPERIMENTAL TECHNIQUES

22

A*

PREPARATION OF BATCHES

22

1®

M a te r ia ls :

22

2®

S y n t h e s is o f B a tc h e s :

23

3®

V o l a t i l i z a t i o n and H om ogeneity:

25

Be

C®

CHEMICAL ANALYSIS OFBATCHES

26

1®

G en eral P r o c e d u r e :

26

2®

R e a g e n ts:

26

a®

S ta n d a rd B a s e -

26

b«

S ta n d a rd A c id -

2?

c*

I n v e r t S ugar S o l u t io n —

27

de

I n d ic a t o r S o lu t io n s

27 £ *I

3®

Sam pling and W eighing o f Sam ples:

27

A®

D i g e s t i o n o f S am p les:

28

5*

T itr a tio n s :

28

THERMAL ANALYSIS

29

1.

Q uenching:

29

2a

H e a tin g C urve:

29

3®

T w o-L iquid S e p a r a t io n s :

30

4.

C o n sta n t Tem perature P r e p a r a tio n s :

31

D.

V II

PETROC-RAPHIC STUDIES

31

EXPERIMENT^ RESULTS

33

A*

BATCHES

33

Bo

IMMISCIBILITY REGION

34

C*

HEATING CURVE RESULTS

35

Do

X-RAY PATTERNS

38

DISCUSSION OF RESULTS

40

A«

THERMAL ANALYSIS

•41

B©

JMMISCIBXLITY REGION

t/

Ca

STRUCTURE OF LIQUIDUS

45

Do

INVESTIGATION OF Mg0*B2 0 ?

47

SUMMARY AND DISCUSSION

B i b l i o graphy

I.

STATEMENT OF PROBLEM

The o b j e c t o f t h i s r e s e a r c h i s to d e te r m in e t h e p h a se e q u i l i b r i a i n th e s y s te m , magnesium o x id e - b oron o x id e as c o m p le te ly a s th e e x ­ p e r im e n ta l te c h n iq u e s and equipm ent p e r m it.

The p r i n c i p a l e x p e r im e n ta l

l i m i t a t i o n i s t h a t o f th e p r o d u c tio n o f h ig h te m p e r a tu r e s ♦

The t e s t s

a r e e x te n d e d t o te m p e r a tu r e s a t t a i n a b l e in t h e p la tin u m -rh o d iu m c a sca d e fu r n a c e and p la tin u m ware made f o r t h i s r e s e a r c h * In a d d it io n to i t s academ ic i n t e r e s t , th e s o l u t i o n o f t h i s problem i s

c o n t r ib u t io n t o th e e v e r grow ing s to r e h o u s e o f p h a se

e q u ilib r iu m d a ta from w h ich so o f t e n u n p lan ned and u n e x p e c te d b e n e f i t s came* The g e n e r a l u se o f b o r ic a c i d as a m in e r a liz e r i s w e l l e s t a b ­ lish e d ®

T h is p r o p e r ty h as been a p p lie d to m a g n esia and m a g n e sia -

c o n t a in in g bodies®

A know ledge o f th e r e a c t i o n s o f b o r ic o x id e w ith

magnesium o x id e h a s d i r e c t b e a r in g on a p p lic a t io n s o f t h i s ty p e*

I I HISTORICAL

The p u rp o se o f t h i s s e c t i o n i s to d i s c u s s b r i e f l y c e r t a i n p a p ers s e l e c t e d from t h e abundant l i t e r a t u r e r e l a t i n g to th e s tu d y o f h ig h tem p era tu re p h a s e - e q u ilib r iu m p rob lem s i n g e n e r a l, and t o r e v ie w r e f e r e n c e s t o t h e m a t e r ia ls u se d i n t h i s r e s e a r c h .

T h is i s

n o t in te n d e d t o be a c o m p le te s u r v e y o f t h e p a p ers on t h e g e n e r a l tech n iq u es®

One t n e s e s u b j e c t s some o f t h e a r t i c l e s t h a t w ere fo u n d

t o b e e s p e c i a l l y u se fu l, i n t h i s work are m e n tio n e d .

A.

MATERIALS 1®

B o r ic O xid e: Anhydrous b o r ic o x id e i s r e a d i l y p re p a r e d a s a pure g l a s s

by s im p le i g n i t i o n a t te m p e r a tu r e s around 1 3 0 0 °C o f b o r ic a c id o r '•b o ric a c id a n h y d r id e ,"

1

(3b) ,

th e in d e x 1*4637 Na f o r

(io)

g la s s .

^

(4 o ) 0

W in c h e ll ( 4 -5 ) g i v e s

The g l a s s i s s t r o n g l y h y g r o s c o p ic

The p r e p a r a tio n o f c r y s t a l l i n e b o r ic o x id e p r e s e n te d a d i f f i c u l t problem b e c a u se o f t h e s tr o n g g l a s s fo rm in g te n d e n c y o f t h e B2 O3 str u c tu r e ® lo w p r e s s u r e ,

In 1934> by h e a t in g b o r ic a c id a t a b o u t 2 0 0 °C tinder

( u n t i l th e sp e cim en s h e a te d a t 1 0 0 0 °C f o r t h i r t y m in u te s

showed no w e ig h t l o s s ) , C o le and T a y lo r ( 2 .)

o b ta in e d a p r o d u c t h a v in

an abrupt m e lt in g p o in t a t 2 9 4 * 1 °C t h a t gave a s h a r p - l in e ty p e o f x -ra y d if f a c t io n p a tte r n .

By h o ld in g B^O^ g l a s s , p rep a red a t 1400°C ,

a t a tem p era tu re ab ou t 2 3 0 °C, above th e s o f t e n i n g p o in t o f t h e g l a s s b u t b elow th e 2 9 4 °C p o i n t , t h e y p rep a red m a t e r ia l g i v in g x - r a y and

in d e x r e s u l t s t h e same a s i n t h e c a s e o f t h e vacuum d eh y d r a te d b o r ic a c id .

I n v ie w o f more r e c e n t work i t ap p ears t h a t t h e p h a se o b ta in e d

wa 3 n o t c r y s t a l l i n e BpO^* M cC ulloch ( 25) i n 1 9 3 8 o b t a in e d , from p a r t i a l l y d e -h y d r a te d open m e l t s , c r y s t a l s a n a ly z in g 9 9 -3 p e r c e n t B2 O3 ® He r e p o r t e d th e m e ltin g p o i n t a s b etw een 4 6 0 and 4 7 0 °C®.

E x p erim en ts c o n d u cted b y

K racek, M orey and Merwin w ere i n p r o g r e s s a t t h i s tim e a t t h e Geo­ p h y s i c a l L a b o ra to r y in W ashington on "The S y ste m , W ater-B oron O xide In a v e r y e x a c t and th o r o u g h s tu d y o f th e s y s te m t h e y g iv e a co m p le te d i s c u s s i o n o f t h e c r y s t a l l i z a t i o n problem *

B2 Q3 d o e s n o t

sp o n ta n eo u sly c r y s t a l l i z e from, d eh y d r a te d m e lt s % s e e d s o f HBO - I a r e n e c e s s a r y t o a c t a s n u c le i*

I f a m e lt i s d eh y d r a te d beyohd th e

HBOg-I s t a g e , n o c r y s t a l l i z a t i o n o c c u r s u n le s s seme c r y s t a l s o f HBOghappen t o remain®

The a u th o r s p r e s e n t a d e t a i l e d h e a t in g s c h e d u le

f o r th e c r y s t a l l i s a t i o n p ro cess® A t t h e tim e o f t h e i r p u b l i c a t i o n , t h e l a r g e s t c r y s t a l s t h e y had o b ta in e d w ere s t i l l t o o s m a ll f o r co m p le te p e t r o g r a p h ic exam in a­ t i o n , b e in g a b o u t 0 . 0 5 mm. i n d ia m e t e r .

C r y s t a ls o f B2 O3 had th e

a s p e c t o f rhom bohedra, and w ere n e a r ly or q u i t e u n i a x i a l w it h o f ,o r f} and y ) = l * 6 4 g , and

4 (o r °c) = l e 6 l^ »

C ru sh in g e i t h e r in d u c e s

a m inute l a m e lla r tw in n in g o r p o s s i b l y r e v e a l s a tw in n in g c a u sed b y in v e r sio n ®

Numbers i n p a r e n t h e s e s r e f e r t o b ib lio g r a p h y a t end o f d is s e r t a t io n ®

The m e lt in g p o in t o f B2 O3 , 450 + 2°C * , r e p o r te d by K racek, e t a le

( 2 0 ) , was d e te r m in e d b y means o f t h e q u en ch in g t e c h n iq u e ,

w ith t h r e e days a llo w e d f o r th e a tta in m e n t o f e q u ilib r iu m a t each te m p e ra tu r e«,

T h is i s i n e s s e n t i a l agreem en t w it h M cC ulloch*s v a lu e *

There i s

c o n s id e r a b le l o s s o f B2 O3 t y v o l a t i l i z a t i o n when

b o r ic a c id i s fu se d *

In t h e p r e s e n c e o f b u t s m a ll amounts o f w a t e r ,

h ow ever, BpCb h as a v e r y lo w v a p o r p r e s s u r e , b e in g p r a c t i c a l l y n o n v o l a t i l e in t h e co m p lete a b se n c e o f w a t e r , ( 2 .0 ) e H2 O-B2 O3 ,

In t h e system

( 2.0 ) , v o l a t i l i z a t i o n m ust be a s c r i b e d t o t h e p r e s e n c e o f

compounds s t a b l e in. th e v a p o r ph ase*

The lo w v a p o r p r e s s u r e o f

n e a r ly c o m p le te ly d eh y d r a ted b o r ic a c id a c c o u n ts f o r t h e n eed o f h ig h te m p er a tu r es f o r co m p le te d eh y d r a tio n * C o le and T a y le r ( 2 -) m easured t h e v a p o r p r e s s u r e o f m olten a t te m p e r a tu r e s b etw een 1200 °C and 1 4 0 0 °C b y means o f t h e dynamic m ethod w it h N2 as t h e i n e r t gas*

I n t h e c a l c u l a t i o n s t h e y assum ed

a sim p le m o le c u le f o r B2 O3 i n th e g a se o u s s ta te ®

The r e s u l t i n g

v a lu e o f t h e rnola.1 e n tr o p y o f v a p o r i z a t io n , 3 2 *2 , su p p o r ts t h i s a ssu m p tio n i n i t s

c l o s e n e s s t o t y p i c a l v a l u e s f o r p o la r l i q u i d s

(H2 O - 3 2 * 0 , CH3 OH - 3 3 * 4 )*

T h eir r e s u l t s a r e a s f o ll o w s : Vapor P r e s s u r e (Mm. o f M ercury)

1.200

0*83

1250

2*0

13 0 0

3 -4

1350

6 .9

1400

12*0

5

Sou th ard (4C>) g iv e s d a t a on t h e l o s s o f w e ig h t upon i g n i t i o n o f c r y s t a l l i n e B2 03 «

The o r i g n i a l

a n a ly s e d :

B2 0 3

99®73$

H2 0

0®12

O ther im p x iriti.es

0 *15

H ea tin g o v e r n ig h t a t 3 7 5 °C g a v e: B2 0 3

99®£2$

H2 0

0®03

The i g n i t i o n l o s s w as d eterm in ed b y t h e f u s io n o f t h e c r y s ta ls ® The w e ig h ts w ere ch eck ed on an u n s e a le d c a p s u le c o n t a in in g t h e f u s e d B2 0 3 a t 1 1 2 5 , 1 2 5 0 , and 1 5 0 0 °C« 0*03 p e r c e n t in

Up t o 3.500°C, w here th e sam ple l o s t

s e v e r a l hours* t h e r e was v i r t u a l l y no l o s s i n w eight®

As a b o v e , t h i s i n d i c a t e s t h a t anhydrous B2 0 3 has a v e r y lo w v a p o r p r e s s u r e up t o 1 5 0 0 °C® 2e

Magnesium O x id e : Two form s in w h ich MgO can b e added t o b a tc h e s a re t h e

ca rb o n a te and t h e p r e c a lc in e d oxide®

L atim er and

H ild eb ran d ( 2.1 )

g iv e f o r th e forrrmla o f th e b a s i c c a r b o n a te , Mg^(0 H) 2 (C03 ) 3 ♦ 3 H2 0 , I t i s i n t h i s form , t h a t t h e CP c a r b o n a te i s a v a ila b le ®

Such a

c o m p o sitio n upon i g n i t i o n s h o u ld y i e l d 4 4 .1 4 p e r c e n t MgO®

(The

ca rb o n a te u se d in t h i s r e s e a r c h i g n i t e d t o 4 1 . 0 p e r c e n t MgO®)

The

ca rb o n a te can b e ta k e n i n t o s o l u t i o n d i r e c t l y or ca n be c a lc i n e d when used®

The o x id e i s v e r y r e a c t i v e t o w a te r vapor u n le s s v e r y s t r o n g l y

ca lcin ed ® MgO®

G r e ig ( ' 3 ) d e s c r ib e s t h e p r e p a r a t io n and u se o f c a lc in e d

The m e ltin g p o i n t o f MgO was d eterm in ed i n g r a p h ite c r u c i b l e s by K an olt ( IB) i n an Arsern g r a p h ite r e s i s t a n c e fu r n a c e w ith a ft, a tm o sp h ere.

The v ie w in g p a th f o r th e o p t i c a l p yrom eter was sw ep t

c le a r o f v a p o r b y means o f a g a s d r a f t j an y r e a c t io n o f th e c r u c i b l e and th e MgO c r e a t e s o n ly CO and Mg v a p o r s .

The r e s u l t s o b t a in e d i n

s i x d e t e r m in a t io n s , w it h an a v era g e d e v ia t io n o f 1 3 °C, was 2 8 0 0 °C„ MgO v a p o r iz e s c o m p le te ly i n v a cu o b e fo r e t h e m e lt in g p o in t i s r e a c h e d , K a n o lt (^ 8 ) ,

The l o s s i n n e u t r a l or o x i d i z i n g atm osp h ere

up t o 1 8 0 0 °C, i s n e g l i g i b l e , Morre and P a t r ic k (2 .7 ), w h ile seme d i s s o c i a t i o n i n vacu o a t 1 9 0 0 °C has b e e n r e c o r d e d . The o p t i c s 1 p r o p e r t ie s r e p o r te d i n W in c h e ll (4 5 ) a r e : I s o m e tr ic i n c u b e s , o c ta h e d r o n s and g r a in s w ith p e r f e c t 100 c le v a g e and im p e r fe c t 111 le a v a g e « NaCl sp a c e l a t t i c e .

C r y s t a ls h ave th e

C o lo r le s s ,

I s o t r o p i c w it h n * 1#734--1«737« B.

SYNTHESIS OF BATCHES, In work i n v o l v i n g v o l a t i l e c o n s t i t u e n t s , g ra d u a l h e a t in g

sc h e d u le s d e c r e a s e v o l a t i l i s a t i o n l o s s e s b y a llo w in g r e a c t io n s o f th e com ponents t o ta k e p la c e b e f o r e v e r y h ig h te m p e r a tu r e s a r e r e a c h e d , G e lle r and B u n tin g (u ) , F a u st and P eek ( 7 ) ®

I f p r a c t i c a b l e , th e

co m b in a tio n o f t h e v o l a t i l e c o n s t i t u e n t w it h one o f th e o th e r con ­ s t i t u e n t s b e f o r e th e s y n t h e s is o f th e f i l i a l b a tc h e s h e lp s s o l v e th e p rob lem , F l i n t and W e lls ( 8 )« In. sy ste m s i n v o l v i n g B2 0 ^ , two g e n e r a l m ethods o f b a tc h p r e p a r a tio n have been u s e d .

In th e f i r s t

(w hich i s th e m ethod u se d

i n t h i s r e s e a r c h ) , t h e b o r ic a c id (o r anhydrous I^O^) i s i g n i t e d t o

c o n s ta n t w e ig h t and th e am ounts o f o t h e r com ponents are c a l c u l a t e d on t h e b a s is o f t h i s weight®

The seco n d m ethod i n v o l v e s t h e a d d it io n o f

th e B2 O3 a s b o r i c a c i d , w it h e s t im a t e d a llo w a n c e s made f o r v o l a t i l ­ i s a t i o n , t o t h e o th e r components®

I n e i t h e r c a s e , a n a ly s is o f th e

b a tc h e s i s n ecessa ry ® The v o l a t i l i z a t i o n o f i s n e g lig ib le * iz a tio n o f

from a lr e a d y com bined m ix tu r e s

C a r lso n ( 4 ) r e p o r t s t h a t , b y a n a l y s i s , v o l i t i l from p r e p a r e d b a tc h e s when t h e y w ere s u b s e q u e n tly

u s e d i n h e a t in g c u r v e s was n o t a p p rec ia b le ® (4 / ) r e p o r t t h e

T orop ov and K anovalov

same foi* t h e i r work w i t h MgO and

t h e i n f l u e n c e s o f r e p e a t e d m e lt in g s on t h e

C®

^

regard to

com p osition ®

CHEMICAL ANALYSIS* Of t h e numerous m ethods o f a n a l y s i s f o r

and m ost u s e d i s t h e t i t r a t i o n o f t h e m a n n it o l, i n v e r t su g a r or g ly c e r o l®

as H^BO^ f o r t i f i e d w ith I n t h e s e t i t r a t i o n s t h e H^BO^

com p lex a c t s a s a r e l a t i v e l y s tr o n g m on ob asic acid® makes th e m o st e co n o m ic a l reagen t®

t h e s im p le s t

I n v e r t su g a r

A v a r i e t y o f i n d i c a t o r s has b een

u s e d , b u t t h e m ethod i n v o l v e s i n e a c h c a s e th e n e u t r a l i z a t i o n o f th e s o l u t i o n t o a pH o f a b o u t 5 w ith an i n d i c a t o r u n r e s p o n s iv e t o b o r ic a c id , f o llo w e d b y th e a d d it io n o f m a n n it o l, or th e l i k e , and t i t r a t i o n t o pH 8 w it h s ta n d a r d base®

K racek , M orey and M erwin (ZO)

u se d Ba(QH)p s o l u t i o n , m a n n ito l and p h e n o lp h t h a le in in t i t r a t i n g m e ta b o r ic a c i d m o d ific a tio n s ® In d e te r m in in g CaO and B2®3* Gar,l s °n ( 4 ) f i r s t t i t r a t e d t h e CaO w ith 0*5 N HC1 s o l u t i o n u s in g m e th y l r e d , t h e a c id a c t i n g as s o l v e n t f o r t h e sample®

The

was th e n t i t r a t e d w ith 0®5N

NaOH t o t h e p h e n o lp h th a le in e n d p o in t u s in g m a n n ito l*

A pesper b y S c h a fe r and S i e v e r t s (3 6 ) p r e s e n ts two m eth o d s| t h e o ld e r u s e s * - n a p t h o lp h t h e le in f o r th e pH 8 i n d i c a t o r , w h ile th e new p roced u re u s e s m e th y l r e d , or p e r f e r a b ly b ro m c r e so l p u r p le , f o r both th e i n i t i a l , n e u t r a liz a t io n , and t h e f i n a l t i t r a t i o n *

V ery co m p le te

d e t a i l s a r e g iv en * A " p a r t it io n law " m ethod b a se d on t h e r e l a t i v e s o l u b i l i t y o f b o r ie a c id in w a te r and i n an e t h e r - e t h a n o l m ix tu r e i s d is c u s s e d by G laze and F in n ('£■) as b e in g u s e f u l i n g l a s s a n a ly s e s * F or s m a ll q u a n t i t i e s o f E^O-j , Geg, A nderson and Payne ( /.* / ■CO A

' I —i

»

nrtr n / n

f*~\

CGR

1

3

5 °/rain t o 9 r0 .

8 4 5 -1 1 6 0 98 7 1143

1

1

rJaUOUs > .a.

7 7 5 -1 1 7 0

T

1

B a tc h .

6 70—1200 °8 5

i.

1

B a tc h .

8 5 0 -1 1 7 0 035 1 1 4 0

41

.2..

2

A;w„0

SSO-13C5 985 1139

67

2

1

B a tc h .

8 5 0 -1 2 9 0 988 1141 1219

68

2 ■2

AQ.j 1 1 7 0 f o r 15 m in; l^ /m in to 1 1 2 5 .

1

1

B a tc h .

57

T

2

1 1 6 0 -1 1 3 0 f o r 3 h r ; t o 9 7 0 ; * ,O ’,.«, -H '•
' »

22 43 - 3 5 6 .2

.

V)D 11/2

1 0 7 0 - 1 2 6 0 — _ 1145 ---------

)r1 1 2 6 6 8 4 5 -1 2 7 5 no/.. 17 7

1137

1

47

4

■1

48

/

2

AQ.

9 0 0 - 1 2 0 0 980 1136

1

1

B a tc h .

8 7 0 -1 3 2 5 985 1126 1303

0

1

1 0 6/m in t o 1 1 5 0 j 4 0/m in to 1 1 0 0 ; AQu

3 1 5 -1 3 2 5 986 1136 T 5P

0

i f i ’ /m’ n t.n

62 63 /■ _i

29

4 6.4

ro

C

'S

11-50: ..A0/m in to

3 2 5 -1 3 1 0

48

•'

*D4

Ar‘ Jis,«

900-12GCj980 1X36

62 29 26.4 53.

1

1

Batch.

o 70-1325| 985 1126 1303 i

f\r-

CCR 4

63

2

1

1 0 % in to;1150j 4 s/min to

315-1325 986 1136 1313

CCR 5

64

2 .2

1 0 % in to 11-50;'..4 V oin to

325-1310!

1090; AQ-.

2 3

1 0 % 'in to 850.

DC

2 4

1165 to 1115 a t 1° per min; to 1040 in 2 :2G.y Batch,

42 24 47-8 5

^

OCR 6

350-1315

65

:

850-13401983 1125 1319 1123 130S

43

2 1

49

3

1 Batch,

905-1330 983 1126 1308

4

1 AQ4> Batch.

900-1340 983 1125 1308

51

4

2 1300 to 875 in 7:30.

375-1340

52

4

3 10°/nin to 1135; 2 3/min to 950; to 420.. ; 6

910-1345 c-% 1142 1309

50

■

AQ. + Batch.

1040-1310

915-1345

1

Batches are a ir quenched and are ground to pass a IGO-aesh screen,

2

AQ. * a ir quenched.

r

r>jcf

1C in d icates very *6ak, questionable, 'effect#. ir.'iicates no e ffe c t was found rh ere one is to be expected.

1144 130Q

CCR 2

Table

(continued )

H ea tin g Curve R e s u lts

B Yfeight % No MgO B20 3

c R

o

5

6

1

1

B a tc h .

33

1

2

AO.

39

1

3

1 0 “/m in to 1190.

1

1

B ate!;.

.1

2

1

76 r7*7

Run No. 'X

37;

73

15

30

2

4

53.2 4 6 .8

5 3 .3 4 6 .2

74 75

85 :

31

32

5 5 .4 4 4 .6

56.3 4 3 .7

86

78

34

58.8 4 1 .2

79 80

33

6 0 .5 3 9 .5

P re c o o lin g o f Charge 7

Temp. I n te r v a l s .3

Endotherm ic E ffe c ts .

Remarks

9

830-1370

1337

870-1370

1337

1190-1375

1338

/ 890-1375

1339

1 0 “/m in to 1220.

1220-1370

1340

1

B a tc h .

1110-1365

1311

1334

'.

R e c a le sc e n e e .

2

1

6 °/m in t o 1245; AQ., + B a tc h .

1180-1330

1312

1334

CCR 8 .

R e c a le sc e n e e .

2

2

5°/rain to 1190; AQ.

1155-1365

1326

1333

R e c a le sc e n e e „

1

1

B a tc h .

1250-1350

1315

1330

R e c a le sc e n e e .

1

2

1 0 “/rain to 1190.

1220-1360

1

1

Batch*

1240-1355

1

2

3 “/rain

—•>_L 1

.

. -

:

1350 t o 1150.

1325 1313

1140-1360

1326

CCR 9 ; r e c a le s c e n e e m easured.

1326

B atch

1145-1380

1311

1344

CCR 10.

5“/rain to 1120; + B atch.

1045-1400

1313

1341

CCR 1 1 .

R ec a le sc e n e e .

31

2

82

2

o

4 °/rain to 1300; AQ.

1240-1390

1319

1349

AQ.; no r e c a le s c e n e e .

1

i■ X

Batch.,

1170-1420 :

1305

1339

CCR 12; no r e c a le s c e n e e .

1

2

5 “/m in to 1120.

1220-1400'

1314

1361

AQ.; no r e c a le s c e n e e .

33 84

35

6 2 .6 3 7 .4

AQ.

2

2

4 °/n iIn t o 1300; AQ.

1 2 4 0 -1 3 9 0

1319

1349

AQ.; no r e c a l e s c e n e e .

1

1

B atch.

1 1 7 0 -1 4 2 0 .

1305

1339

CCR 12; no r e c a l e s c e n e e .

1

2

5 °/m in to 1 1 2 0 .

1 2 2 0 -1 4 0 0 '

1314

1361

AQ.; no r e c a l e s c e n e e .

1

1

B a tc h .

9 7 5 -1 3 9 5

1357

1364

1

2

AQ.

1 2 1 0 -1 3 9 0

1

1

B a tc h .

1 1 2 5 -1 3 9 0

1

2

4 a/in in to 1250; AQ.

1 2 3 0 -1 3 9 0

1369

1

3

1 0 °/m in t o 12 50..

1 2 6 0 -1 3 8 5

1361

1

4

AQ.

1 2 6 0 -1 3 9 0

1362

1

1

B a tc h .

1 1 7 0 -1 3 9 0

1357

M elted ; up T. C. W ires l / 8

.1

2

1 2 5 0 -1 3 9 0

1 360

No c h a n g e .

2

1

8 ° /m in t o 1290; l ° / m i n t o . 1250. B a tc h .

1 2 5 0 -1 4 7 0

1359

M e lte d .

2

2

8 ° /ra in to 1300; AQ.

1 3 0 0 -1 5 0 0

1359

C o n s id e r a b le c r e e p .

1

1

B a tc h .

1 2 5 5 -1 3 9 0

1355

Not a l l m e lt e d .

1

2

3 °/m in t o 1 2 5 0 ..

1 2 5 5 -1 5 0 0

1358

S e ttle d

1

3

AQ.

1 2 2 0 -1 4 0 0

1360

C lu s te r o f c r y s t a l s on T. C. W ire,

100

1

4

■8c/m in t o 1 1 5 0 .

1 2 5 5 -1 3 9 0

1359

No c h a n g e .

107

2

1

B a tc h .

1 2 7 5 -1 5 6 0

1359

C om plete s e t t l i n g .

103

2

2

1 2 8 0 -1 6 0 5

1354

1

1

1 2 ° /rain to 1400; 3 ° / t o 1200 B atch

1 2 1 0 -1 4 5 0

1357

In mound around T. C. l e a d s .

102

1

2

4 */m in to 1260.

1 2 5 5 -1 3 9 0

1360

Not a l l . m e lt e d .

103

1

3

8 % i n to 1270.

1 2 7 0 -1 3 9 0

1362

No c h a n g e .

104/

1

4

8 °/m in to 1230.

1 2 3 5 -1 5 0 0

1361

No c h a n g e.

2

1

B a tc h .

1 2 6 0 -1 6 0 0

1359

A ppears m e lte d ; up T . C. W ires 1 /8 " .

532; 33

35

6 2 .6

37.4.

8487

36

38

6 7 .0

3 3 .0

.

39.

37

9C

.

67 .0 ' 3 3 .0

91 92

.

:

95.

33

.7 1 .5 2 8 .5

9o

105

.

106

97

39

73^

2 6 .3

98 • 99

101

.109

:

40

7 6 .0 2 4 .0

■

AQ.

.

.

'

1357 1353

1363

CCR 1 3 .

M e lte d .

Up i n Wound.

•

36

The r e p r o d u c i b i l i t y o f t h e r u n s w as f o u n d t o o f th e d i f f e r e n t i a l re a d in g a f t e r p a ssin g i t s i n g l y rap id ®

The s h a r p p e a k i s

be v e r y good®

The r e c o v e r y

maximum v a l u e i s e x c e e d ­

used as th e te m p e ra tu re d e te rm in in g p o in t

in a l l e ases» C e rta in v a r ia r io n s w ere fo u n d as a r e s u l t o f d i f f e r e n t p r e ­ v io u s h e a t t r e a t m e n t s o f t h e charges® s h a r p e r th e r m a l e f f e c t s upon m e l t i n g ,

N a t u r a l l y , a. p h a s e w i l l g i v e th e b e t t e r i t

is c ry sta llise d *

S lo w c o o l i n g t r e a t m e n t s t h r o u g h c r i t i c a l t e m p e r a t u r e r a n g e s w e r e g iv e n c h a rg e s i n o r d e r to d e v e lo p th e d e s ir e d p h ases* W ith in l i m i t s th e m a g n itu d e o f th e d i f f e r e n t i a l i n th e effect is

a f u n c t i o n o f t h e s i a e o f t h e c h a rg e ®

"When o n l y h a l f t h e

u s u a l c h a r g e w a s a d d e d t h e p e a k s w e r e r o u g h l y one h a l f t h e u s u a l h e ig h t * C o o lin g c u rv e s gave l a r g e u n d e r c o o lin g e f fe c ts ®

The m o s t

i n t e r e s t i n g o f t h e s e w as a p r o n o u n c e d r e c a l e s c e n e e e x h i b i t e d b y b a t c h e s c o n s i s t i n g o f m i x t u r e s o f 2MgO*BpOo a n d 3Mg0«B20o«,

The

e f f e c t , w as v e r y s t r o n g i n t h e b a t c h e s c o n t a i n i n g 5 4 - 4 , 56*3 a n d 3 8 * 8 w e i g h t p e r c e n t o f MgO, c a u s i n g a b r i g h t f l a r e - u p a n d a v e r y f a i n t c l i c k i n g n o is e upon c r y s t a l l i s a t i o n * w as t o o l a r g e

A lth o u g h th e d i f f e r e n t i a l a f f e c t

a n d t o o r a p i d t o b e m e a s u r e d p r e c i s e l y , t h e b a t c h temper™

a t u r e w as r a i s e d a b o u t 75 t o 1 0 0 ®C a n d t h e d i f f e r e n t i a l r e a d i n g f e l l to th e o r ig in a l v a lu e w ith in a lu m in a

60 s e c o n d s „

( r e f e r e n c e m a t e r i a ] . ) -was r a i s e d

The t e m p e r a t u r e i n t h e a b o u t

1 5 °C*

The r e c a l e s c e n e e

t o o k p l a c e a r o u n d 1 1 9 0 °C a f t e r v a r i o u s s c h e d u l e s f o r c o o l i n g fro m a b o v e th e liq u id u s •

I n a 6 0 * 5 p e r c e n t b a t c h t h e c r y s t a l l i s a t i o n w as n o t so

a b r u p t a n d t h e u n d e r c o o l i n g w a s l e s s , w i t h h o r e c a l e s c e n e e i n som e c o o lin g s *

The r e c a l e s c e n e e t o o k p l a c e o v e r a n i n t e r v a l i n b a tc h

c o m p o s it io n s a b o u t 6 p e r c e n t w i d e , c e n t e r e d a b o u t t h e SMgOE^O^ e u t e c t i c , a t 57®8 w e i g h t p e r c e n t MgO* H e a t in g c u r v e s i n t h e t w o - l i q u i d z o n e sh ow ed o n l y tw o w e l l se p a r a te d b r e a k s.

From 670® t h e r e w as n o s i g n o f a n y b r e a k s b e lo w t h e

988® o n e , i n c o n t r a s t t o t h e r e s u l t s r e p o r t e d b y T o ro p o v a n d K o n o v a lo v ( 4 - / ) i s e e s e c t i o n VI® F ig u r e 5 , H e a t in g C u rve No® 4-6, sh o w s a t y p i c a l h e a t i n g c u r v e on a b a t c h h a v in g a c o m p o s i t io n b e tw e e n t h a t o f t h e MgO'BpO^ and t h e 2MgO*

co m p o u n d s.

t h e r m ic e f f e c t s .

I n t h i s t y p e o f c u r v e t h e r e a r e t h r e e en d o —

The f i r s t ,

is

t h a t due t o th e d i s s o c i a t i o n , or

in c o n g r u e n t m e l t i n g o f t h e MgO^l^O^ com pound a t 9 8 8 1 5**C®

When

t h e t e m p e r a t u r e h a s r i s e n t o 1 1 4 -2 ± 5 °C , t h e p r o c e s s e s a t t e n d i n g t h e ap p earan ce, b ecau se o f th e im m is c ib ilit y r e g io n , o f th e seco n d liq u id make a s e c o n d b r e a k occu r©

From t h i s t e m p e r a t u r e u n t i l t h e f i n a l

liq u id u s i s r e a c h e d c o n s id e r a b le m e lt in g t a k e s p la c e *

T h is i s

show n

b y t h e d e p r e s s i o n o f t h e d i f f e r e n t i a l r e a d in g o v e r a n e x t e n d e d p e r io d ® The s u d d e n r i s e

a t t h e en d o f t h i s r e g u l a r p e r i o d i s

a t t a i n m e n t o f t h e f i n a l liq u id u s ©

c a u se d b y t h e

At t h is p o in t th e f i n a l c r y s t a ls

o f SMgOoB^O^ m e l t , and t h e e n d o t h e r m ic e f f e c t s a r e e n d e d .

The o t h e r

v a r i a t i o n s i n t h e d i f f e r e n t i a l a r e d ue t o t h e v e r y s m a l l tem p e r a t tir e in c r e a s e s in th e fu r n a c e a s th e c u r r e n t i s

i n c r e a s e d m a n u a lly .

I n t h e r e g i o n b e tw e e n t h e SMgO-BpC^ and t h e IMgO^BpO^ com­ p o u n d s t h e h e a t i n g s c u r v e s g a v e tw o b r e a k s p a r t i a l l y s u p e r im p o s e d , w i t h o n e o c c u r r i n g p a r t w a y dow n, o r u p , t h e o t h e r b r e a k .

For

0.0600

1300

.0400

.0200

T im e in Seconds

I£00

2400

\ 3000

3600 /

4200

4800

■mo

in

1100

-0600

1000

M000

~.I400

Degrees

ISO0

Figure 51 heating Cutve /Vo. 4 7 900

Tem perature

500^

Centigrade

1200

.0000

38

b a t c h e s n e a r e s t t h e e u t e c t i c t h e e u t e c t i c b r e a k was v e r y p r o m in e n t , w h ile t h e f i n a l li.q u id u s e f f e c t becam e m ore p r o n o u n ced as t h e c o m p o s it io n s l e f t t h a t o f t h e e u t e c t i c and a p p r o a c h e d e i t h e r o f t h e com pounds* W h eth er t h e c h a r g e w as -"100 pow der o r a l r e a d y m e lt e d down c o n s i d e r a b l y a f f e c t e d t h e m a g n itu d e o f t h e d i f f e r e n t i a l *

The - 1 0 0

p o w d e r s , i n a lm o s t a l l c a s e s g a v e l a r g e r te m p e r a tu r e d i f f e r e n t i a l s th a n d id t h e m e l t e d c h a r g e s u pon r e s p e c t i v e s u c c e d in g r u n s*

In t h e b a tc h e s

r i c h e r i n MgO th a n t h a t 3Mg0*B20^ c o m p o s it io n , 6 3 * 6 9 w e ig h t p e r c e n t , t h e c h a r g e s on t h e f i r s t r u n s g a v e l a r g e , ’’d o u b le p r o n g e d ” p e a k s w i t h a s m a l l p a r t i a l r e c o v e r y i n t h e d i f f e r e n t i a l b e f o r e t h e f i n a l d rop p r o c e e d in g t h e v e r y r a p i d r i s e i n d i f f e r e n t i a l a t t h e m e ltin g ®

A ll

b a t c h e s i n t h i s r a n g e g a v e t h i s t y p e o f s t r u c t u r e i n t h e f i r s t run on e a c h ch a rg in g ®

H o w ev er, i n a l l t h e s u b s e q u e n t ru n s on e a c h o f

t h a c h a r g e s a. s i n g l e sh a r p p e a k w as o b t a in e d (e x c e p t i n t h e tw o 6 7 * 0 p e r c e n t b a t c h e s w h e r e tw o e f f e c t s c l o s e t o g e t h e r vrere f o u n d ) »

A

d e f i n i t e e x p la n a tio n f o r t h i s e f f e c t h as n o t b een fo u n d , b u t t e n t a t i v e l y I t I s a t t r ib u t e d t o s e t t l i n g o f th e f i r s t s u r fa c e l i q u i d in to th e p o w d ery c h a r g e d u r in g t h e m e lt in g *

D®

X-RAY PATTERNS To o b t a i n e v id e n c e b ey o n d t h a t o f t h e m ic r o s c o p e on t h e

q u e s t i o n o f t h e e x i s t e n c e o f MgO'BgO-j and on t h e r e l a t i o n o f t h i s compound t o t h e 2 MgO’ B2 0 3 c e r t a i n c h a r g e s vrere p r e p a r e d f o r x - r a y s t u d y b y b e i n g h e l d a t c o n s t a n t te m p e r a tu r e arid th e n a i r q u e n c h e d , o r s l o w l y c o o l e d th r o u g h c r i t i c a l r a n g e s * i n T a b le 2 ,

T h e se t r e a t m e n t s , d e s c r ib e d

c o m p r is e C o n s ta n t T em p era tu re Runs 5 , 7 , 8 and 1 4 .

39

Pow der d e f f r a c t i o n p a t t e r n s w e r e rim b y P« C o r b e t t o f t h i s D epartm ent®

The p a t t e r n s w e r e ta k e n w i t h c o p p e r K r a d i a t i o n w i t h t h e

f i n e l y g ro u n d s a m p le s c e m e n te d on c o p p e r w i r e s w i t h Canada balsam ® film

d a ta a r e g iv e n i n th e f o llo w in g t a b le s

T a b le 5

1

5

24

4 7 .8

2

1055

2 :0 0

4

2

5

24

4 7 .8

2

1055

*®

D e v e lo p Min i n D -1 9

B a tc h N o.

0 0

E x p o su re ( i n hrs>)

CTR N o.

01

T r e a tm e n t Hr a t °C

F ilm N o.

3 .5

3

7

18

2 5 .9

12

950

2 :0 0

3 .5

4

8

24

4 7 .8

12

950

2 :2 0

4

5

14

26

37®6

S lo w c o o l i n g p ast 9 9 0 °

2 120

4

Wt.jK MgO

T h e se p a t t e r n s a r e d i s c u s s e d i n S e c t i o n VI©

The

40

VI DISCUSSION OF RESULTS

The p h a s e - e q u i l i b r i u m shown i n F ig u r e 6® of

^ 0

d ia g ra m d e t e r m in e d i n t h i s

N o t show n i n t h e f i g u r e i s

research i s

e it h e r th e m e ltin g p o in t

1 2 4C a s m e a s u r e d b y K r a c e k , M orey an d M erw in,

t h a t o f MgO, d e t e r m in e d b y K a n o lt a s 2 8 0 0 °C.

(2-°)

or

No i n d i c a t i o n s o f s o l i d

s o l u t i o n w e r e f o u n d , a n d t h e d ia g r a m i s draw n on t h e u s u a l b a s i s o f n o t r e p r e s e n tin g a v e r y lim it e d s o l i d a r ie d *

T h is p r a c t i c e i s

s o u l t i o n s t h a t o c c u r a t p h a s e bound—

d i s c u s s e d c o m p l e t e l y b y M arsh (2-4)®

e s t a b l i s h e d IMgOBpOq an d BMgdBoQ^ com pounds a r e c o n fir m e d *

The w e l l The

e q u a l m o l e p e r c e n t com pound, MgO®B2 0 ^ , w h ic h h a s b e e n and d e n ie d i n t h e lite r a tu r e i s in v o lv e d ®

fo u n d t o e x i s t e v e r o n l y p a r t o f t h e te m p e r a tu r e r a n g e

I t is

c o n s id e r e d t h a t t h e c o n t r o v e r s i a l n a t u r e o f t h e s t a t e ­

m en ts c o n c e r n in g t h e MgO^BgO^ i s

e x p l a i n a b l e i n t h e l i g h t o f t h e in c r o n —

g r u e n t m e l t i n g o f t h e compound®

The s u p e r p o s i t i o n o f t h e z o n e o f

i m m i s i c a b i l i t y u p on t h i s in e r o n g u e n t m e l t i n g m akes an i n t e r e s t i n g reg io n ® The p a r t o f t h e s y s t e m on t h e MgO s i d e o f t h e tw o l i q u i d

zone,

(w h ich

en d s a t 3 6 . 0 w e i g h t p e r c e n t o f MgO), c o n s i s t s o f s t r a i g h t f o r w a r d e u t e c t i c str u c tu r e s® B ec a u se o f th e d i f f i c u l t i e s i n t h e r e g i o n b e tw e e n p u r e

i n s y n t h e s i z i n g an d a n a l y z i n g b a t c h e s

and t h e l i q u i d u s r i s i n g a b r u p t l y t o t h e

tw o l i q u i d z o n e , n o a t t e m p t w as made t o ru n e x p e r im e n t s i n t h i s t i o n range®

c o m p o si­

The h i g h e s t MgO c o n c e n t r a t i o n t h a t c o u ld b e t e s t e d w as

l i m i t e d b y t h e t e m p e r a t u r e t h a t c o u ld b e a tta in e d ® The p h a s e d ia g r a m d e t e r m in e d b y T o ro p o v and K o n o v a lc p u b l i s h e d w h i l e t h i s r e s e a r c h w as i n

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rve d a t a . L i q u i d Z o n e bg A n al y s i s . ' t e d ” du rin g h e a t i n g c u r v e run At i id s rc n

3

K r a c k , M orey and Merwln ( 2 - ° ) , and t h e s t a r t o f t h e i m m i s c i b i l i t y gap a t 0 * 6 w e i g h t p e r c e n t o f MgO and 1 1 4 2 + 5 °C ,

( a c c o r d in g t o t h i s r e s e a r c h ) ,

t h e r e i s n o d i r e c t e v id e n c e o f t h e s t r u c t u r e o f t h e l i q u i d u s « th e p o s s i b i l i t i e s or,

o f e ith e r

T h ere a r e

(a ) e x te n s iv e s o li d s o lu t io n in t h is a r e a ,

( b ) a s im p le e u t e c t i c s tr u c t u r e ®

I t is

q u ite l i k e l y t h a t th e s o li d

s o l u t i o n o f Mg0 ®B2 0 3 i n B2 O3 , a lt h o u g h s m a ll i n a b s o l u t e am ount o c c u p ie s a la r g e f r a c t i o n o f th e a v a ila b le area*

The in c o n g r u e n t m e l t in g o f MgO*

B2 O3 com pound m u st ea.use a ch a n g e i n t h e c u r v a t u r e o f t h e l i q u i d u s a t 9 8 8 + 5 ° C .,

( t h e te m p e r a tu r e o f t h i s e f f e c t a s d e t e r m in e d i n t h e p r e s e n t

w o r k ) , i n t h e u s u a l m anner a s s o c i a t e d w it h t h i s t y p e o f e f f e c t ®

V ery

r e f i n e d t e c h n iq u e s w o u ld b e n e c e s s a r y i n o r d e r t h a t a n y e x a c t d a t a c o u ld b e o b t a in e d In t h i s r e s t r i c t e d r e g i o n .

46

The t e m p e r a t u r e o f t h e l i q u i d u s on t h e i m m i s c i b i l i t y r e g io n i s 114-2 £ 5°C»

As p r e v i o u s l y m e n tio n e d , t h e i m m i s c i b i l i t y z o n e e x t e n d s t o

h ig h t e m p e r a t u r e s w i t h o u t a n y n o t i c e a b l e ch a n g es*

No a tte m p ts a t e x ­

p e r im e n t a l d e t e r m i n a t i o n o f t h e s l o p e o f t h e c u r v e s e p a r a t i n g t h e t w o l i q u i d r e g i o n from t h e s i n g l e l i q u i d a r e a w e r e a tte m p te d * From 3 6 * 0 t o

5 3 * 6 6 w e i g h t p e r c e n t o f MgO, ( t h e 2Mg0®B20^ com­

p o s i t i o n ) , t h e l i q u i d u s c u r v e r i s e s s m o o t h ly t o 1 3 4 0 £ 5 ° 0 , -the m e lt in g p o i n t o f 2M g0eB2 0^« com pounds i s

The e u t e c t i c b e tw e e n t h e 2Mg0«B2 0^ and th e 3Mg0«B2 0^

a t 1 3 1 3 £ 5*0 and com es a t 57»8 w e ig h t p e r c e n t o f MgO*

From

t h i s e u t e c t i c t h e l i q u i d u s t e m p e r a tu r e i n c r e a s e s t o 1 3 6 6 £ 5 °C , t h e m e l t i n g p o i n t o f 3MgO®B2Q3 a t 63©46 w e ig h t p e r c e n t o f MgO* To t h e r i g h t o f t h e 3 MgO®B2 0 3 compound o n ly o n e b a t c h c o m p o s it io n , 6 7 * 0 p e r c e n t , g a v e w e l l s e p a r a t e d b r e a k s f o r t h e e u t e c t i c an d t h e f i n a l m e ltin g e f f e c t s „

T h se s r u n s f i x e d t h e l i q u i d u s c u r v e a t 1 3 6 4 £ 5°C

f o r t h e co m p o so tio a ©

I n t h e r u n s on b a t c h e s r i c h e r i n MgO o n ly t h e e u t e c —

± c t e m p e r a t u r e , 1 3 5 3 ± 5°C , w as o b ta in ed ®

A lth o u g h c h a r g e s w ere run t o

t e m p e r a t u r e s a t w h ic h t h e y a p p e a r e d t o h a v e b e e n c o m p le t e ly m e lt e d d u r in g t h e r u n , f i n a l l i q u i d u s e f f e c t s w ere n o t fo u n d on e i t h e r s i d e o f t h e e u t e c t i c , t h e e x a c t c o m p o s it io n o f w h ic h c o u ld n o t b e d e te r m in e d *

1'he

s m a ll th e r m a l e f f e c t r e m a in in g when t h i s s t e e p l i q u i d u s was r e a c h e d made no d e t e c t a b l e i n f l u e n c e on t h e t e m p e r a tu r e d i f f e r e n t i a l . *

A

f a s t e r h e a t i n g r a t e w o u ld d o u b t l e s s h a v e im p ro v ed t h e d i f f e r e n t i a l a t t h i s p o in t*

B u t a f a s t h e a t i n g s c h e d u le a t s u c h a h ig h te m p e r a tu r e w ou ld

h a v e b e e n d e s t r u c t i v e t o t h e p la tin u m r e s i s t a n c e w in d in g o f t h e f u r n a c e . A good i n d i c a t i o n o f t h e l o c a t i o n i s c o n d itio n o f th e b a tc h e s

g iv e n from t h e o b s e r v a t i o n s on t h e

a f t e r t h e v a r io u s ru n s*

S in c e t h e b a t c h e s i n

t h i s c o m o o s i t i o n .range c o n s i s t e d o f 3M»B and MgO, i t

i s o b v io u s t h a t t h e

47

s l o p e o f t h e l i q u i d u s r i s i n g t o t h e MgO m e l t i n g p o i n t i s l a r g e , its

c u r v a t u r e i s sm all®

and t h a t

I n t h e d ia g ra m a d o t t e d l i n e from t h e MgO

m e l t i n g p o i n t , p a s s i n g b e tw e e n t h e " m elted " and " u n m e lte d 11 p o i n t s , s t r i k e s th e e u t e c t i c

is o t h e r m a t a b o u t 7 2 p e r c e n t *

T h is v a l u e i s

te n ta tiv e ly

a c c e p t e d a s t h e 1 iq u id u s c o m p o s itio n *

Do

INVESTIGATION OF M g O B p O ^ , ■

S in c e th e e x is t e n c e

o f th e

com pound, MgOB^O^,

o w in g t o t h e d is a g r e e m e n t s i n t h e l i t e r a t u r e ,

w as i n d o u b t

on e o f t h e e s p e c i a l l y

i n t e r e s t i n g p a r t s o f t h i s r e s e a r c h c e n t e r e d a b o u t t h e p r o b le m o f p r o v in g o r d is p r o v in g th e e x is t e n c e

o f t h i s compound®

The f i r s t f e s t s made on b a t c h e s i n t h e n e ig h b o r h o o d

o f th e

50

m o le p e r c e n t , 3 6 * 6 7 w e i g h t p e r c e n t c o m p o s it io n seem ed t o i n d i c a t e t h e a b s e n c e o f a n y s u c h corapoundo

S lo w c o o l i n g o f b a t c h e s th r o u g h t h e l i q u i d u s

p r o d u c e d o n l y m ix t u r e s o f g l a s s and t h e d im agn esiu m b o r a t e , w h i l e q u en ch ed s a m p le s g a v e a t y p i c a l c o n f u s e d m ix tu r e o f v e r y p o o r l y d e v e lo p e d c r y s t a l s em bedded i n 'g la s s * , quenched ch a rg es*

L i t t l e c o u l d b e d e te r m in e d m i c r o s c o p i c a l l y on t h e s e The d a t a o b t a in e d i n d i c a t e d t h a t a t l e a s t a t t h e l i q —

u id u s t h e com pound d id n o t e x is t ® To s t u d y t h e p o s s i b i l i t y o f t h e e x i s t e n c e o f t h e compound up t o t h e t e m p e r a tu r e o f t h e f i r s t h e a t i n g c u r v e e f f e c t , a t 9 8 8 °C «, c h a r g e s o f c o m p o s it io n s c o v e r i n g a c o n s id e r a b l e r a n g e on e i t h e r s i d e o f t h e 1 : 1 c o m p o s it io n and a l s o

o n e s v e r y n e a r t h e MgO-BpO^ c a l c u l a t e d p e r c e n t ­

a g e w ere h e l d a t te m p e r a t u r e s a b o v e and b e lo w 9 8 8 °C® c o o l e d th r o u g h v a r io u s t e m p e r a tu r e r a n g e s * i n T a b le 2*

Some w e r e s l o w l y

T h e se e x p e r im e n ts a r e l i s t e d

4-8

E ven "with t h e c a r e f u l l y c o n t r o l l e d h e a t t r e a tm e n t o f t h e c h a r g e s n e a r t h e t h e o r e t i c a l c o m p o s it io n , go o d c r y s t a l s i n a t i o n w e r e n o t o b t a in e d ,,

f o r m ic r o s c o p ic exam­

D e f i n i t e c o n f ir m a t io n o f a p h a se b e s i d e s

t h e g l a s s a n d t h e d im a g n esiu m b o r a t e was n o t a cco m p lish ed ® H o w ev er, t h e d e v e lo p m e n t o f t h e 2MgOB 2 0^ c r y s t a l s w as a f f e c t e d i n t h e m anner t o b e e x p e c t e d i f

t h e MgOoB^O^ d id e x i s t up t o 9 8 8 °C*

B a tc h I S c o n t a i n i n g 2 5 # 9 w e ig h t p e r c e n t g ave v e r y p o o r c r y s t a l d e v e lo p ­ m en t o f a n y k in d when a i r q u en ch ed from t e m p e r a t u r e s b e lo w 988*0®

When

t h i s b a t c h w as h e l d b e tw e e n 9 8 8 ° and 1 1 4 2 °C 2 : 1 c r y s t a l s w ere fo r m e d and a r e l a t i v e l y l a r g e amount o f g l a s s w as p r e se n t®

S a m p les o f B a tc h 2 6

c o n t a i n i n g 37.. 6 w e i g h t p e r c e n t o f MgO show ed p o o r d e v e lo p m e n t o f t h e 2 : 1 c r y s t a l s when c o o l e d th r o u g h t h e 9 8 3 °C r a n g e , w h e r e a s th e n t h e y w ere a i r q u e n c h e d fro m b e tw e e n 9 8 8 ®C an d 1 1 4 2 °C t h e d e v e lo p m e n t o f 2 : 1 c r y s t a l s w as much b e t te r ®

B a tc h 2 4 , 4 7 ®8 w e ig h t p e r c e n t , g a v e much

b e t t e r d e v e lo p m e n t o f t h e 2 : 1 c r y s t a l s t h a n B a tc h 2 6 upon s i m i l a r h e a t trea tm en t® A l s o , a v e r y e n c o u r a g in g , m a c r o s c o p ic e f f e c t w as o b s e r v e d i n t h e d e g r e e o f c a l c i n a t i o n and s h r in k a g e o f t h e c h a r g e s h e l d i n t h e co n ­ s t a n t te m p e r a tu r e runs®

The i n d i c a t i o n s o f t h e am ounts o f l i q u i d form ed

d u r in g t h e v a r i o u s ru n s c o r r e l a t e d w it h t h e r e s u l t s t o b e e x p e c t e d i f t h e com pound w as s t a b l e up t o 9 8 8 °C« and m e lt e d i n c o n g r u e n t l y t t t h a t t e m p e r a t u r e , fo r m in g SMgOBpC^ and B2 O3 r i c h liq u id ®

B a tc h e s h e l d

b e tw e e n t h e 1 : 1 a n d 2 : 1 c o m p o s itb n s a t te m p e r a t u r e s b e lo w 9 8 8 * 0 w e r e s t i l l i n pow der form®

When t h e s e b a t c h e s h e ld a b o v e 988 °G and b e lo w

1 1 4 2 °C t h e r e w as some s h r in k a g e and l i q u i d

form ation ®

49

To c o n fir m t h e e x i s t e n c e o f t h e com pound, s a m p le s w e r e s e l e c t e d f o r X ~ ra y e x a m in a t io n , a s i n d i c a t e d i n T a b le s 2 and 5 , o f th e p a tte r n s i s

The p r e p a r a t io n

d i s c u s s e d i n s e c t i o n V -D,

The p a t t e r n s w e r e ex a m in ed v i s u a l l y ® i n t e n s i t y o f v a r io la s g r o u p s o f l i n e s

The p r e s e n c e , a b s e n c e and

co n v ir m s t h e e x i s t e n c e o f MgO*B2 0 3 «

The f o l l o w i n g F ilm num bers r e f e r t o t h o s e i n T o b le 5* l i n e s p r e s e n t i n F ilm 3 , a r e c a u s e d b y t h e MgCPB^O^®

The c h a r a c t e r i s t i c F ilm s 1 an d 2

show e i t h e r no t r a c e o r o n ly t h e v e r y f a i n t e s t t r a c e o f MgOBgO^ c h a r a c te r is tic l in e s .

T h e se f i l m s h a v e a d i f f e r e n t s e t o f u n iq u e l i n e s

t h a t a r e n o t fo u n d i n F ilm 3® w ith th e 1 : 1 l i n e s

F ilm s 4 and 5 c o n t a in b o t h s e t s o f l i n e s ,

s t r o n g e r i n F ilm $ and t h e 2 : 1 s t r o n g e r i n F ilm 4

a s i s t o b e e x p e c te d ® As d i s c u s s e d a b o v e , t h e e x p e r im e n t a l e v id e n c e c o n fir m s t h e e x i s t e n c e o f t h e com pound, MgO*BpO^ up t o 9 8 8 °G»

The compound d o e s

n o t c r y s t a l l i z e r e a d i l y s o t h a t good p e t r o g r a p h ie s a m p le s a r e o b t a in e d w ith d if f ic u lt y ®

L i k e w i s e , t h e X -r a y d i f f r a c t i o n p a t t e r n s a r e weak®

E q u ilib r iu m , c o n d i t i o n s o f s e p a r a t i o n ,

a s shown b y t h e X—r a y r e s u l t s on

th e b a tc h e s h e ld a t c o n s ta n t te m p e r a tu r e , a r e a t t a in e d s lo w ly i n b a t c h e s h a v in g c o m p o s it io n s b e tw e e n 3 0 and 50 w e ig h t p e r c e n t o f MgO a t t e m p e r a t u r e s b e lo w 1 1 4 5 °Ce

50

V II

SUMMARY AND CONCLUSIONS*

The s /s t e r n 2 MgO—3 2 ^3 a h a s b e e n i n v e s t i g a t e d b y m eans o f s ta n d a r d c h e m i c a l , t h e r m a l and o p t i c a l t e c h n i q u e s , and t h e p h a s e d iagram f o r t h e s y s te m h a s b e e n c o n s tr u c te d ® The l i q u i d u s c u r v e h a s b e e n e s t a b l i s h e d from 0 * 6 t o 70 w e ig h t p e r c e n t MgO b y m eans o f h e a t i n g c u r v e s , s u p p le m e n te d b y c o n s t a n t te m p e r a tu r e w ork*

The th e r m o c o u p le s u s e d w ere c h e c k e d a g a i n s t a s ta n d a r d

and a g a i n s t t h e known m e l t i n g p o i n t s o f K^SO^ and 2 Ca0 °B2 0 2 © A z o n e o f i m m i s c i b i l i t y e x t e n d s from 0 * 6 t o 3 6 * 0 w e ig h t p e r c e n t MgO; t h e s e l i m i t s w e r e d e te r m in e d b y a c h e m ic a l a n a l y s i s * The t h r e e i n t e r m e d i a t e com pounds p r e s e n t i n t h e s y s t e m a r e : MgQ’ I^O^ — m e l t s i n c o n g r u e n t l y a t 9 8 8 + 5 °C; 2MgO

“ meTbs c o n g r u e n t ly a t 1 5 4 0 ± 5 °

3 Mg0 *B2 0 3 ~ m e l t s

C, and

c o n g r u e n t ly a t 1 3 6 6 + 5 °C®

Good c r y s t a l p r e p a r a t io n w as n o t r e a l i z e d w it h t h e MgO^^O^, and n o d e f i n i t e o p t i c a l d a t a w as o b t a in e d on t h i s compound* K o n o v a lo v ( 4 1 ) g i v e

f o r ¥ § 0 8 2 0 3 b ia x ia l ( - ) la r g e

“ 1*617®

w as

2MgO*B2°3

1 * 6 3 5 , n * 1*660*

2V , Ng

t o he b ia x ia l ( - ) w ith

2V

T orop ov and »1 * 6 6 1 , ®3 0 ° , n

Np «

T o ro p o v a n d K o n o v a lo v r e p o r t f o r 2MgO*B 0 b i a x i a l •* 5

( —) w i t h n ” 1 * 6 7 3 ,

n “ 1 * 6 5 9 ., n “ 1 * 5 8 8 *

W in c h e ll ( 4 5 ) g i v e s

f o r 3Mg0*B 2 0 3 :

ViThite G « 2*99 O rth o rh o m b ic a : b : o * 0*641

s 1 : 0*549®

c r y s t a l s p r i s m a t i c w it h good 1 0 0 c le a v a g e ®

5/

B i a x i a l ( 4-)«

2 V * 21 + 1 °

O p tic p la n e i s 010* * 1*6527; N

- 1*6537; N

- 1*6748*

Z « C, H e a t in g c u r v e t e s t s on c h a r g e s r i c h e r i n MgO th a n 67% gave o n ly t h e e u t e c t i c t e m p e r a t u r e , 1 3 5 8 ± 5 ° 6 &J b e tw e e n t h e 3 * 1 compound and MgO®

No th e r m a l b r e a k s w e r e fo u n d a b ove t h i s te m p e r a tu r e a lth o u g h

c h a r g e s w e r e a p p a r e n t ly m e lt e d c o m p le t e ly i n s o n s o f t h e r u n s .

The

melting o r non-Biel ting of the various charges at different temperatures g a v e an i n d i c a t i o n o f t h e p a th o f t h e l i q u i d u s from t h e MgO m e l t i n g p o in y t o t h e e u t e c t i c te m p e r a tu r e i n q u e s t io n s

The v a l u e e s t im a t e d

i n t h i s m anner i s 7 2 . 0 w e i g h t p e r c e n t MgO, a s com pared t o t h e 7 2 .5 w e ig h t p e r c e n t r e p o r t e d b y T orop ov and K o n o v a lo v ( 4 1 ) ®

___

The SMgOBpOq m e l t s c o n g r u e n t ly a t 1 3 6 6 * 5 * 0 , and t h e 2MgO* Bo0 o a t 1 3 4 0 + 5 &c.-, w i t h t h e in t e r m e d ia t e e u t e c t i c a t 1 3 1 3 ± 5 0C« and 2 3 ~ 57©? w e i g h t p e r c e n t MgO.

T h is i s

t o b e com pared t o 1300"' and 5 7 .0

w e ig h t p e r c e n t r e p o r t e d b y T orop ov and K onovalov® From t h e 2Mg0 B> 0^ c o m p o s it io n t h e l i q u i d u s c u r v e f a l l s f a i r l y r a p i d l y t o t h e 3 6 . 0 w e ig h t p e r c e n t a b s c i s s a , w h ere t h e im m is c ib ility

r e g io n b e g in s .

The l i q u i d u s t e m p e r a tu r e o f t h i s

zon e i s 1 1 4 2

± No m ea su rem en ts w e re made i n t h e n a rro w zon e b e tw e e n 9 9 * 4 and 1 0 0 w e ig h t p e r c e n t B2 O3 *

The l i q u i d u s m u st f a l l i n t h i s zon e t o t h e

4 5 0 °C m e l t i n g p o i n t o f c r y s t a l l i n e

52

B i b l i o 2 ra p h y 1»

0 . He B u r g e s s and A. H o lt., "The B e h a v io r o f M e t a l l i c O x id e s Tow ards F F u se d B o r ic A n h y d r id e " , P r o c . Chen. S o c . ^ 9 , 2 2 1 - 2 2 2 (1 9 0 3 )

S . S . C o le s a d N. V . T a y l o r , "The S y stem Nas 0 oBE03 " , 2. " I. P r e p a r a t io n o f C r y s t a l l i n e B2 0 3 and Some o f I t s P r o p e r t i e s " , J . Am. C e r . S o c . I S , 5 5 - 3 8 ( 1 9 3 5 ) 3.

"IV . V apor P r e s s u r e s o f B o r ic O x id e , Sodium A le ta b o r a te , and Sodium L ib o r a t e b e tw e e n 1 1 5 0 °C and 1 4 0 0 °C " , The P e n n s y lv a n ia S t a t e C o l l e g e , M in e r a l I n d u s t r i e s E x p e rim en t S t a t i o n , T ec h . P a p e r No. 3-4, 1 9 3 4 .

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7.

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(1 8 4 8 ) 3 3 , 34 (1 8 5 1 )

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and L . S . V e i l s , "The S y stem Lime—B o r ic O xid e—S i l i c a " , N a t l . B u r . S t a n d a r d s , 1 7 , 7 2 7 -7 5 2 ( 1 9 3 6 ) , RP 9 4 1

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Marc F o e x , "So1.’a b i l i t y o f O x id e s i n F u se d B o r ic A n h y d r id e " , A n a l. Chim. 3 1 , 359-4-09 ( 1 9 3 9 )

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R. F . Ge3!ar & E . N. B u n t in g , "The S y stem Fb0-B 2 0 3 " , J . R e s e a r c h N a t l . Bur® S ta n d a r d s 1 8 , 5 8 5 - 5 9 3 ( 1 9 3 7 ) RP 995

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R. F . G e l l e r and E . N. b u n t in g , "The S y stem F b 0 -B 2 G3 ~ S i0 2 " , J • R e s e a r c h N a t l . B u r . S ta n d a r d s 2(3, 2 7 5 - 2 8 3 ( 1 9 3 9 ) RP 1 2 3 1

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F . V . G la z e and A. N . F in n , " R o u tin e D e t e r m in a t io n o f B oron i n J . R e s e a r c h N a t l . B u r S ta n d a r d s 1 6 , 4 2 1 - / 2 9 ( 1 9 3 6 ) EP 8 8 2

G la s s " ,

13.

J . "W "» G r e r g , " I n n i s c i o i l x t y i n S i l i c a t e m e lt s " , An* Jo S c i 13., 3.—4 4 , 1 3 3 - 1 5 4 ( 1 9 2 7 ) , 1 A , 4 7 3 - / 8 4 (1 9 2 7 )

14.

,W. G u e r t l e r , "Uber d i e G ren sen d e r I .l s c h b a r k e i t von B o r s a u r e a n h y d r id und B o r a t e s im S c h m e lz f u s s " , Z» a n o r g . Chem. AO 2 2 5 —2 o 8 (1 9 0 4 )

15.

w . G u e r t l e r , "ITcer d i e S c h a e lz p u n k te d e r m isch u n g en d e r s l k a l i s c h e n E rden m it B o r a a u r e a n h y d r id e " , Z. a n o r g . Chen. 40 (3 ) 3 3 7 - 3 5 4 (1 9 0 4 )

53

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M* H« G eg, Be A n d erso n and C. J„ P a y n e , "Some Nevr B a ta c o n c e r n in g K o r n e r u p in e and I t s c h e m i s t r y 11, M i n e r a lo g ic a l Mag. and J . M in e r a lo g i c a l S o c . , L ondon 26 ( 1 7 5 ) 1 1 9 -1 3 G (1 9 4 1 )

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,ja. Hu g i l l H* M a tts and J . V y s e , " R e a c tio n s i n M ix tu r e s o f C h ro m ite, M a g n e sia and A lu n in a . I* I n f l u e n c e o f B o r ic A cid and Calcium . F lu o r id e i n P r o m o tin g C o m b in a tio n " , T r a n s . 'B r it . C e r . S e e . 40 (1 0 ) 3 6 3 -7 9 (1 9 4 1 )

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C, W. K a n o lt , "The M e lt in g P o i n t s o f Sorae R e f r a c t o r y O xid es" 5 J* Mash* A ca d . S c i . 8 , 315 ( 1 9 1 5 )

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20*

F . C. K r a c e k , M orey and H. B . M er g e s, 15The S y s te m , M a ter — B o ro n O x id e 11, Aon. J . S c i . V, 3 5 -A , 1 4 3 - 1 7 1 (1 9 3 8 )

21.

W. M* L a tim e r and J . H. H ild e b r a n d , " R e fe r e n c e Book o f I n o r g a n ic C h e m is tr y " , The M a c m illa n C o ., Per; Y o rk , 194.0

22.

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23.

B* M a lla r d , Ann. d e s l i n e s ,

24.

J . S . M arsh, " P r i n c i p l e s o f P h a se D ia g r a m s" , M eG raw -H ill Book C o ., I n c . , New Y o rk , 1935*

25.

L« M c C u llo c h , "A c r y s t a l l i n e B^Oa5], (1 9 3 7 )

26*

J . W. M e l l o r , "C o m p reh en siv e T r e a t i s e on I n o r g a n ic and T h e o r e t i c a l C h e m istr y " , V o l. V, 9 6 - 9 8 , Long n a n s , G reen and C o ., New Y ork , 1 9 3 9 .

27*

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28.

G* W. M orey, "A. C om parison o f t h e P le a tin g Curve and Q u en ch in g M ethods o f M e l t i n g - P o in t D e t e r m in a t io n s " , J . W ash. A cad . S o i l 12. (14-) 326 (1 9 2 3 )

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30*

G, J . M o r r is , " R e f r a c t o r y L a b o r a t o r y F a r e fr o m Bonded P e r i c l a s e " , B . S . T h e s i s , The P e n n s y lv a n ia S t a t e C o l l e g e , J u n e , 1 9 3 7

33 »

P . N i g g l i "Das Magma Und S e in e P r o d u k te " , 1. T e i l , P h y s ik a lis c h - C h e m is c h e G ru n d la g e n , L e i p a i g , 1 9 3 7

j

N o v -D e e .

(1 8 9 1 )

( lo S 7 )

Am. Chem. S o c . 5 9 , 2 6 5 0 —2 6 5 2

(1 9 3 5 )

S4

32a

F 0 H- H orton " C r i t i c a l S tu d y o f t h e D i f f e r e n t i a l Therm al M ethod f o r t h e S tu o y o f C lay M in e r a ls , J . Am. C er. S o c . 22 5 4 - 6 3 (1 9 3 9 )

33e

h. R o b e r t s , "The G e o p h y s ic a l L a b o r a to r y F u rn ace T h e r m o sta t" , J . O p t. S c o . Am. F e v . S c i . I n s t r . 1 1 1 7 1 -1 8 6 (1 9 2 5 )

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35«

P .o eser and H. T . W e n z e l, "M ethods o f T e s t in g T h erm ocou p les T h erm ocou p le M a t e r ia l: ^ J . R e se a r c h N a t l. B u r . S ta n d a r d s 1 4 (3 ) 2 4 7 -2 8 2 (1 9 4 8 ) RP 768

36.

K. S c h a f e r and A. S i e v e r t s , " T it r im e t r ic D e t e r m in a t io n o f B o r ic A cid 1,1 Z . anal® Chem. 1 2 1 . 1 6 1 —169 (1 9 4 1 )

37.

E . S . sh e p h e r d and G. A. P a n k in , " B in a ry S y stem s o f A lum ina w it h S i l i c a , Lim e and M a g n e sia " , Am. J . S c i . 2 8 . 208 (1 9 0 9 )

38®

8 e B„ S la w so n and A . B . P e c k , "The D e t e r m in a t io n o f The R e f r a c t iv e I n d i c e s o f M xnei-als b y t h e Im m ersion Method"., Am. m in e r a lo g i s t 2 1 . 5 2 3 -5 2 8 (1 9 3 6 )

39«

P . L . S m ith , " S t u d ie s on t h e S t r u c t u r e o f G la s s b y t h e M ethod o f Gas D i f f u s i o n " , D o c t o r Ss D i s s e r t a t i o n , The P e n n s y lv a n ia S t a t e C o ll e g e , A u g u st, 1 9 3 7 .

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S . C. S o u th a r d , "Therm al P r o p e r t ie s o f B o r ic O x id e " , J . Am. Chem® S o c . 6 2 3 1 4 7 - 3 1 5 0 (1 9 4 1 )

41.

N. A* T orop ov and P . F« K on ovalov "The B in a r y S y stem M agnesium O xide B o r ic A nhydride" ( i n R u s s ia n ) , Z h u r. F i z . Khim. ( U .S .S .I t. ) 14., 1 1 0 3 — 1 1 0 9 (1 9 4 0 )

42.

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43.

B . E , W arren and A. G. P in c u s , " A to n ic C o n s id e r a t io n o f t h e I m m is c ib i l i t y I n G la s s S y s te m s " , J . Am. Cer* S o c . 2T3 (1 0 ) 3 0 1 - 3 0 4 (1 9 4 0 )

44®

T« W a ta n a b e, " K o t o it e , A New R o c k -fo im in g M agnesium B o r a te " , M in e r a lo g . and P e t r o g . M i t t . 5 0 . 4H--4-62 ( 1 9 3 9 ); C er. A b s t r a c t s 1 £ (3 ) 75 (1 9 4 0 )

45.

A. N« W i n c h e l l , " -M icroscop ic C h a r a c te r s o f A r t i f i c a l M in e r a ls " , 2nd E d ., John W ile y and S o n s , i n c . , 1931®

and

A ck n o w led gem en t

To Dr® N e l s o n T a y lo r and t h e c o m p le te s t a f f o f t h e C e r a m ic s D e p a r tm e n t, a l l o f whom, h a v e h e lp e d i n t h i s w ork i n in n u m e r a b le w a y s , t h e a u t h o r e x t e n d s h i s a p p r e c ia t io n ®

S p e c i a l th a n k s a r e d u e t o

D r . H. M® D a v is who th r o u g h o u t t h e c o n d u c t o f t h e s e e x p e r im e n ts h a s b e e n a m o s t w i l l i n g a d v i s o r and g u i d e .

Y iith o u t h i s n e v e r c e a s i n g

a i d a n d i n t e r e s t t h i s w ork c o u ld n o t h a v e b e e n a c c o m p lish e d ® The w r i t e r i s i n d e b t e d t o D r . P . D . K r y n in e f o r h i s t r a n s ­ l a t i o n o f t h e w ork o f T o ro p o v an d K o n o v a lo v ( 4 1 ) . I n t h e c o n s t r u c t i o n o f e q u ip m e n t, Mr® S h e e d e r o f t h e M in e r a l I n d u s t r i e s M ach in e Shop h a s g iv e n g r e a t s e r v ic e ® F i n a n c i a l a s s i s t a n c e i n t h i s w ork h a s come fro m a v a r i e t y o f so u rces.

The w o rk w as b eg u n w h i l e t h e w r i t e r w a s a G rad u ate A s s i s t a n t

i n t h i s D epartm ent®

G r a n ts from The P e n n s y lv a n ia S t a t e C o l l e g e C o u n c il

on R e s e a r c h m a t e r i a l l y a i d e d i n t h e c o n s t r u c t i o n o f t h e f u r n a c e and o t h e r eq u ip m en t*

F o r t h e p a s t 1 4 m o n th s, t h e w r i t e r h a s b e e n t h e

r e c i p i e n t o f t h e O rton F e ll o w s h i p g iv e n b y t h e Edward O r to n , J r . , C era m ic F o u n d a t io n , C olu m bu s, O h io .

For a l l th e s e th e w r it e r i s

g r a t e f u l and w is h e d t o e x p r e s s h i s a p p r e c ia t io n ®

very