Investigation of Raw Materials for the Production of Mineral Wool

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NATIONAL RESEARCH COUNCIL OF CANADA DIVISION OF INFORMATI ON SERVICES

Technf c a l T r a n s l a t f on No, 13-10

IhWSTIGATION OF KAIV MATERIALS FOR THE

PRODUCTION OF FAINEHAL WOOL

( I s s l e d o v a n f e S y r f i a d l f a P r o f z v o d s t v a Mfneralnof S h e r s t f )

by

V,F, Zhuravlev and

MOM,

Sychev,

OTTAWA

2 Nsvenber, 1949,

T h i s r e p o r t may n o t be p u b l i s h e d f n whole o r i n p a r t w i t h o u t t h e w r i t t e n c o n s e n t of t h e N a t i o n a l Research Council,

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NATIONAL RESEARCH LABORATORIES Ottawa, Canada

TEZHNICAL TRANSLATION NO0 IS-10 0

E f v f sion o f Informati on Servf c e s

T i t l e : ! I n v e s t i g a t i o n of Raw Materials f o r the ProductLon

0 % Mineral ?Noolo

By:: V,F,

Zhuravlev

and MOM, Sychsvo

Reference J. Zhurnal PrfkUadnof Khimff ( J o u r n a l of Applied

C h s m f a t r y ) Academy of Sef ences,

U,

So S6R,

VcS,

21,

No,

3, March, 194B0 T r a n s l a t e d by: Esther Rabkfn

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JOURNAL O F APPLIED CHEMISTRY, ACADZJrTY OF SCIENCES, U, S o S,R, VOLo 21, N O e 3, MARCH, 19480

PnvestfgatiLon a-a-. of Raw - M a t e r i a l s f o r t h e P r o d u c t f o n of Mineral

-

Woof, bY=

VoFo Zhuravlev and IdoMo Sychev,

Eenfngraz Tsv:hnoEogf c a l I n s t i t u t e Trar1.~kate<3. by E s t h e r Rabki

n

The most i m p o r t a n t p r o p e r t i e s of m f n e r a l wool a r e s smal: weight p e r u n i t volume (from 30 t o 160 kgo p e r 1 hI3) and

a v e r y s m a l l c o e f f i c i e n t of t h e r m a l c o n d u c t i v i t y (from 0 0 0 5 t o 0,07 k aal/M.hro "C). The f a c t t h a t m f n e r a l wool does n o t Pose

i t s heat i n a u f a t f n g p r o p e r t f o s a t f a f r l y h f g h t s m p e r a t u r e s , and

i t does n o t d e t e r i o r a t e from mofsture i s a l s o of c o n s i d e r a b l e impostarlce.

Mineral wool f i n d s wide a p p l f c a t f o n because of t h e s e p p o p e ~ ~ t i e s , Thus, f o r example, m i n e r a l wool i s u s e d a s a h e a t i n s u l a t o r i n b o i l e r i n s t a l l a t i o n s , a s a h e a t f n s u l a t o r and F i l t r a t i n g m a t e r i a l i n chemical a p p a r a t u s and i n r e f r f g e r n t f o n , b u t the bu%%df ng i n d u a t r y i s t h e mai n consumer of m i n e r a l wool a n d its p r o d u c t s o

The c u r r e n t methods f n t h e buf Pding i n d u s t r y , whi ch u t f l f z e p r e f a b r i c a t e d wooden c o n s t r u c t i ons on a l a r g e s c a l e , demand c o n s i d e r a b l e q u a n t i t i e s of h e a t i n s u l a t i n g r n a t e r f a l s such

as m i n e s a l wool, Because of t h i s , i t f a n e c e s s a r y t o e n s u r e t h a t t h e developing i n d u s t r y of m i n e r a l wool p r o d u c t i o n h a s a

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The low c o s t of m i n e r a l wool and t h e p o s s f b f l f t y of utf.11 z i n g raw m a t e r i a l s of varf ous and abundant t y p e s permf t t h e

o r g a n i z a t f on of t h e i n d u s t r y i n regf ons of g r e a t e s t demando

L i t e r a t u r e s o u r c e s f n d f c a t e t h a t a wfde v a r f e t y of raw m a t e r i a l s can be u s e d f o r t h e p r o d u c t f o n of m i n e r a l wool, The use of t h e f o l l o w i n g m a t e r i a l s i s w e l l known8

1, S c h i s t dolomite e s n t a i n f n g c l a y ( P I

2, Minerals of t h e pyroxene group, p a r t i c u l a r i y w o l l a n s t o n i t e ( 2 ) 3, By-products of b a u x f t e (3)

4, Mixtures of c l a y e y s c h i s t , sandstone, c l a y and l i m e ( 4 ) 5, Lime marl w i t h a n admfxture of dolomite ( 5 )

An a n a l y s i s OF v a r i o u s samples of m i n e r a l wool gave t h e f o l l o w i n g v a r i a t i o n s f n t h e composftfon of t h e b a s i c components (6,7,3) Sf02 from 35 t o 46% A 1 2 0 3 from 1 0 t o 30$ Fe203 Prom 0 t o 35% CaO from 4 t o 43% MgO froro 0 t o 18% I n t h e United S t a t e s q u i t e o f t e n m i n e r a l wool f a c t o r f e a a r e b u i

Pt

b e s i d e P o r t l a n d cement f a c t o r i e s , so t h a t t h e y c a n u t i l i z e t h e by-products of t h e raw m a t e r f a l s u s e d i n t h e P o r t l a n d cement i n d u s t r y (9,lO). I n t h e Unfted S t a t e s m i n e r a l s whfch a r e s u i t a b l e f o r t h e p r o d u c t i o n of m i n e r a l wool 1vPthout i n t r o d u c f n g , a n y a d d i t i o n s i n t o t h e m i x t u r e a r e c a l l e d wwoolrockn, b u t t h e r o c k s whfch

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r e q u i r e t h e a d d f t f o n of a substance with e i t h e r a c i d i c o r b a s i c p r o p e r t i e s a r e c a l l e d "subwoolrockn,

The production of mineral wool i s p o s s i b l e from v a r i o u s t y p e s of raw m a t e r i a l and t h e r e f o r e t h e i n d u s t r y can be d i s -

t r i b u t e d throughout wide r e g i o n s of t h e S o v i e t Union where such m a t e r i a l s a r e a v a i l a b l e o The main problem i n choosing t h e raw m a t e r i a l i s t h e s e l e c t i o n of t h e proper mixture which w f l l pro-

duce mineral woo% of t h e n e c e s s a r y q u a l i t y . The s o l u t i on of

t h i s problem I s i n i t s t u r n dependent on t h e methods of e v a l u a t i n g t h e raw m a t e r i a l s and t h e methods of s e l e c t i n g t h e mixtureo

A s i s known, t h e production of m i n e r a l wool i s based on t h e obtainment of a s i l i c a t e f u s i o n and t h e a t o m i z a t i o n of t h e stream of t h i s f u s i o n i n t o very f i n e f i b r e s , Hence, f i r s t of a l l , i t i s n e c e s s a r y t o e s t a b l i s h s p e c i f i c a t i o n s f o r t h e p r o p e r t i e s and composition of s i l i c a t e f u s i ons s u i t a b l e f o r t h e production of mineral wool,

The hollowing c o n d i t i o n s can be e s t a b l i s h e d on t h e b a s i s of t h e d a t a e x i s t i n g i n l i t e r a t u r e s

P o The chemf e a l compositi on of t h e mixture s u i t a b l e f o r t h e production of mineral wool must be such a s t o bnsure t h a t t h e f u s i o n upon cooling w f l l become a g l a s s l i k e s t r u c t u r e without any tendency t o become b r i t t l e ,

2, The chemical composition of t h e mixture must e n s u r e a s u f - f i c i e n t l y low v f s c o s f t y of t h e f u s i o n i n t h e i n t e r v a l of 1250- 135OoC0 The v i u e o s i t y of t h e f u s i on during t h e I n i t i a l moment

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of t h e f i b r e formation determines t o a g r e a t degree t h e q u a l i t y of t h e wool, and i s Gainly r e s p o n s i b l e f o r t h e f i n e n e s s of t h e f i b r e ,

3, The chemical composition of t h e mixture must be such a s t o

allow t h e u t i l i z a t i o n of t h e p r e s e n t l y e x i s t i n g melting a p p a r a t u s , I n cupola and b a t h f u r n a c e s , m a t e r f a l s can be h e a t e d up t o

temperatures of 1500-1600°C, I f we t a k e i n t o account t h a t an overheating of t h e f u s i o n up t o 200-300°C (12) i s r e q u i r e d durfng t h e production, t h e n temperatures of 1200-1250°C w i l l

be t h e optimum l i m f t s f o r t h e melting of t h e mfxtureo

When planning t h e mixture, i t i s good p r a c t i c e t o

c o r r e l a t e t h e e a s e of f u s i b i l i t y of t h e mixture with t h e minimum v f s c o s l t y of t h e f u s i o n ,

The work of Pavlov (13) proves t h a t t h e degree of l i q u e f i c a t i o n of b l a s t - s l a g i s d i r e c t l y p r o p o r t i o n a l t o t h e r a t i o of t h e q u a n t f t i e s of lime and s i l i c a t o c l a y p r e s e n t i n

themc A predomination of Si02

+

A1203 over lime makes t h e s l a g

vf scous, t h i c k and slow-cooling, g r a d u a l l y becoming ( p a s s i n g through a doughy s t a t e ) a g l a s s - l i k e mass, S l a g s i n which t h e r a t i o Si02 + AP203 i s c l o s e t o u n i t y l i q u e f y more easil-y, cool

CaO

more qufckly, becoming a s t o n e - l i k e mass, which g i v e s an ochreous f r a c t u r e , I f t h e q u a n t i t y of lime i s i n c r e a s e d , t h e s e s l a g s

qui c k l y l o s e t h e f r vf s c o s i t y , become thf ck ( " s h o r t " s l a g s ) , and upon coolf ng df s i n t e g r a t e i n t o powder.

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TABLF:

1

Lfme content

9n

s l a g

-

30%

TABLE 2

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TABLE

3 Lime c o n t e n t i n s l a g

-

45%

TABLE

4 Lfme c o n t e n t i n s l a g

-

48% I t i s a l s o n e c e s s a r y t o e x p l a i n t h e e f f e c t of t h e A1203 r a t i o

-

on t h e p r o p e r t i e s of t h e f u s i o n o Sf O2

From a s t u d y of McCaffrey dfagrams on t h e v i s c o s f t y of s l a g 3 i t i s p o s s i b l e t o e x p l a l n t h e e f f e c t of t h e r a t t o I A'2°3

₁

_0.13 1 I I ? p o i s e

.

o o o

--

0.18 7 ' 0.24 0,30

I

0037

I

6

-

I i min 8 ' 1 0

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on the v i s c o s i t y of the f u s i o n f o r a given lime content.

Sf O2

Data expressing t h e e f f e c t of the r a t i o A1203 on t h e Sf O2

vf s c o s f t y f o r f u s f ons with various contents of CaO a t a temperature of 1500°C a r e compf l e d i n Tables 1, 2, 3 and 4.

The following conclusions can be made on the a n a l y s f s o f t a b l e s 1, 2, 3 and 41

1. For low contents of CaO ( &30$) t h e r e i s a s u f f i c i e n t l y wide f n t e r v a l i n which a change i n the r a t i o A1203 (from 0.5

Sf 02

t o 1,O) has l f t t l e e f f e c t on the v f s c o s f t y of t h e fusfona, 2, By f ncreasfng the content of CaO, t h f s f n t e r v a l becomes considerably narrower ( a t CaO

=

40$,, "

--

- -

from 0,2 t o 0,33,

a t 45%

- - - -

from 0.1 t o 0.37); a t a content of CaO cor- reapondfng t o t h e mfnimum vf s c o s i t y (CaO

=

48) thf s f n t e r v a l becomes a p o i n t , I t must be noted, t h a t although a t t h e optimum

o f

content / ~ a 0 , t h f s f n t e r v a l becomes a point the quantf tat1 ve change f n the r a t i o *'z03 is very small,

Sf O2

3, A t a content of lfme l e s s than 30$, and a t an optfmum content of lfme (optfmum from the point of view of obtafnfng minimum

v f s c o s f t y ) a f a f r l y r i d e deviation i n the r a t i o "2O3 i s per- Sf

o,,

6,

mf s e f b l e ,

It i s possible t o c o n t r o l the p r o p e r t i e s of a fusion, obtained from any raw m a t e r i a l , f n order t o lower i t s vfscosfty. Thus a t 1400

-

1600° the i n t r o d u c t i o n of MgO up t o 5% n o t i c e a b l y

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lowers t h e v i s c o s i t y o A g r e a t e r I n c r e a s e I n t h e c o n t e n t of MgO makes t h e f u s i o n even more f l u i d , s o t h a t a t 15-20s of MgO t h e v f a c o s i t y of s l a g s i s 6

--

8 tfmes l e s s t h a n t h e v i s c o s i t y of s l a g s not c o n t a i n i n g MgO, I t i s a l s o e s s e n t f a l t o note t h a t w f t h t h e i n t r o d u c t i o n of I Q O , t h e r e g i o n of f a i r l y f l u i d s l a g s i s widened ( 1 4 ) , Therefore, i n a d d f t i o n t o t h e l f q u e f y f n g a c t i o n , t h e presence of I Q O makes i t p o s s i b l e t o widen t h e l i m i t s of t h e r a t i o *1203 without any e s s e n t i a l

Sf O2

change i n t h e v i s c o s i t y of t h e f u s i o n s ,

There a r e I n d f c a t i o n s t h a t the prejence of Fe203 i n t h e f u s i o n h a s even a g r e a t e r e f f e c t on t h e v ' i s c o s i t y t h a n t h e presence of MgO, p a r t i c u l a r l y i f FeZ03 i s p r e s e n t f n consider- a b l e q u a n t i t i e s,

I n order t o lower t h e m e l t i n g temperature of t h e mix- t u r e , 202% of a l k a l i ( r e c a l c u l a t e d on t h e oxide) a r e added, Sodium s u l p h a t e i a g e n e r a l l y used,

For t h e same purpose BaO may be i n t r o d u c e d up t o 6% (heavy s p a r may be used) a t t h e expense of lowerfng t h e content of CaO, I n t h i a case t h e temperatures of f u s i o n have been

Bswered t o t h e order of 100Oo0 I t must be p o i n t e d out t h a t t h e temperature of f u s i on w i l l a g a i n i n c r e a s e i f t h e percent content of BaO f s i n c r e a s e d ( 1 4 ) ,

I n o r d e r t o r e g u l a t e t h e p r o p e r t i e s of t h e f u s i on, a,

f l u x of t h e type CaF2 can be i n t r o d u c e d i n t o t h e mixture which s ~ m u l t a n e c u s l y lowers t h e temperature and t h e v i s c o s f t y of t h e f u s i on (141,

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According t o Levinson

--

Lessfng (15) t h e halogen s a l t s produce e u t e c t f c s w i t h sf l f e a t e systems, and t h a t t h e s e e u t e c % i c s a r e d i s p l a c e d i n t h e d i r e c t i o n of t h e n o n - s f l f c a t e

eomponen%s, From t h f s p o i n t of vfew, sodfum c h l o r i d e can be used a s a f l u , The p o s s i b i l i t y of u s i n g t h i s f s explafned f n t h e work by .Dflaktorskf (16),

The above s t a t e d can be summarfzed a s followsx

l o The r a t f o Si02 + A1203 should be g r e a t e r t h a n unf t y , which

CaO

w i l l ensure a g l a s s - l f k e s t r u c t u r e upon coolfng, Such a f u s f o n w f l l be a 'slowly coolfng f u s i o n , passfng through a doughy s t a t e , 2, The value of t h e r a t i o c o n s i d e r a b l y a f f e c t s t h e

Sf O2

v f s c o s f t y of t h e f u s i o n a t a d e f f n f t e lime content,

3, Fluxes should be used (dolomite, heavy s p a r , f l u o r s p a r , sodfum s u l p h a t e , sodfum c h l o r f d e ) f o r t h e c o r r e c t 1 on of t h e fusf on,

4, The tendency should be t o obtaf n eomposftf s n s which p o s s e s s m i nfmum f u s f on %emperatweso The f u s i on temperature of t h e mixture should not exceed 1200-1250°C,

S i l i c a t e f u s i o n s must p o s s e s s a number of d e f i n i t e propertf e s whf ch determf ne thef r suf tabf l f t y f o r t h e product1 on of mineral. wool, S p e e f f f e a t i o n s f o r t h e raw m a t e r f a l can be e s t a b l i s h e d by technologPca1 t e s t s , The method of t e s t i n g worked o u t by us i n c l u d e s t h e P o l l o w f n g ~

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( a ) The d e t e r m i n a t i o n of t h e chemical compositi on of t h e r a w

m a t e r i a l s and f l u x e s ,

( b ) The p l a n n i n g of m i x t u r e s on t h e b a s i s of above s t a t e d s p e c i f i c a t i o n s r e g a r d i n g t h e chemical composi

ti

on of f u s f ons,

( e l

The d e t e r m i n a t i o n of t h e f u s i o n t e m p e r a t u r e s f o r t h e s e l e c t e d m i x t w e s ,

The F i b r e q u a l i t y of m f n e r a l wool i s determined by t h e v i s c o s i t y , t h e r a t e of cooling. " d u c t i l i t y " , and, f i n a l l y , by t h e value of t h e s u r f a c e t e n s i o n of t h e f u s i o n , The t o t a l e f f e c t of' t h e vf s c o s i t y , r a t e of c o o l i n g , " d u c t i l f

tyn

and

s u r f a c e t e n s i o n can be a s c e r t a i n e d by a s t u d y of t h e phenomena of t h e s o c a l l e d f l o w a b i l i t y of t h e f u s f ono

Becuause of t h i s , t h e t e s t i n g method should a l s o

i nclude s

( d ) The d e t e r m i n a t i o n of t h e f l o w a b i l i t y of t h e f u s i o n s from t h e s e l e c t e d m i x t u r e s o

( e ) The p r o d u c t i o n of m i n e r a l wool from t h e sample f i s i onso ( f ) The s t u d y of t h e p r o p e r t i e s of t h e o b t a i n e d m i n e r a l wool (composition of t h e f i b r e s , weight p e r u n i t volume, c o e f f i c i e n t of t h e r m a l c o n d u c t i v i t y , h y g r o s c o p i c i t y ) , (g) C o r r e c t i r ~ g , when n e c e s s a r y , t h e p r o p e r t i e s of f u s i o n by i n t r o d u c i n g f l u x e s and by r e p e a t i n g t h e i n v e s t i g a t i o n s of t h e p r o p e r t i e s of t h e f u s i o n and t h e wool, ( h ) To e s t a b l i s h t h e p o s s i b i l i t y of" u t i l i z i n g t h e raw m a t e r i a l s under f n v e s t i g a t i on,

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THE

EXSERINIENTAL SECT1 ON

Method e f i n v e s t i g a t i o n

The temperatuxe of f u s i o n of t h e m i x t u r e was d e t e r - mined by t h e Seger cone i n a KryptoP f u r n a c e ,

The d e t e r m i n a t i o n of t h e f l o w a b i l i t y of t h e f u s i on8

i s c a r r i e d out b y t h e S e l i v a n o v method (17, 181, The method c o n s i s t s of t h e f o l l o w i n g o t h e f u s i o n a t some d e f i n i t e

temperatuke i s poured out o n t o a pouring g a t e l o c a t e d a t a n a n g l e t o She h o r i z o n t a l , The c r o s s s e c t i o n o r t h e p o u r i n g g a t e is i ~ n i f s m Rhroughoue i t s l e n g t h , The P e r g t h of t h e

s t r e a m a f t e r c o o l i n g , and t h e weight of t h e c o o l e d m a t e r i a l a r e measured and t h e r a t 1 o of t h e l e n g t h of t h e stream t o t h e

weigh* of the m a t e r i a l i s c a l c u l a t e d , T h i s r a t i o seTves a s a a t a c d a r d f o r t h e f i o w a b i l i t y o

An i r o n a n g l e 25

x

25 p l a n e d a l o n g t h e i n n e r s u r f a c e s was iased a s t h e pouring g a t e , The a n g l e of i n c l i n a was 16'"

I n l a b o r a t o r y i n v e s t i g a t f ons t h e s e l e c t i o n of t h e method f o r t h e productfon of m i n e r a l wool i s v e r y i m p o r t a n t and q u i t e comp9ex0 The main Tiff f e u h t y f s( t h e f a c t t h a t i t

i s n o t p o s s i b l e t o o b t a i n f u s i ons of consf d e r a b l e quantf t i e s ,

FOP t h e l a b o r a t o r y i n v e s t i g a t f o n s we have s e l e c t e d t h e mechanical method f o r a t o m i z a t i o n ( E n g l i s h p a t e n t Buss (131, w i t h modf-

f i c a t i ons by PerkaY a n d E p s t e i n (12) )

,

The i a b ~ r a t o r y a p p a r a t u s f o r t h e p r o d u c t i o n of m i n e r a l woo% was c o n s t r u c t e d , The

(15)

aoa%terlng!, and t h e n e c e s s a r y equf pment f o r i t s i n s t a l P a t 1 on and e l e c t p i eal conneetf onso

The ~ ~ t a t X n g element consi s t s of a m e t a l l i c p r o p e l l e r t o which a r e a t t a c h e d m e t a l l i c apokes of a s p e c i a l c r o s s -

aec$i on ( s e e photograph), Two such r o t a t i n g elements were pre- paredo One had e i g h t spokes and t h e o t h e r a i x t e e n , The pro- p e l l e r f s mounted on a v e r t i c a l a h a f t a t t a c h e d by two b a l l

bearlnga, The s h a f t i s a l s o s u p p l i e d wf t h a p u l l e y , The whole system f s i n s t a l l e d on a frame on whfch thm electric motor i s moua%edo An A o C o motor of 0 0 5

Kwo

and 1500 spm i s used, The r a t i o between the motor and the p u l l e y cn %he vertica'a a h a f t f a such t h a t t h e element r o t a t e a a % tiipproxi-

mately 4030 spm,

The wool i s obtained i n t h e followf ng manner; a f i n e j e t cf t h e f u s i o n a t a d e f i n i t e temperature i s poured onto the apokes cf the r ~ t a t i n g element, The spokes due to the h i g h ~ s t a t i o n a P v e l o c i t y of t h e element (4600 x L6

-

64,000 blows on t h e j e t pe% minute) break up t h e j e t i n t o miriute drops whfch during t h e f l i g h t a r e d r a m out i n t o f i n e f i b r e s ,

I n order t o p r o t e c t t h e worker from t h e s p a t t e r i n g 9 of t h o fusf on, a s p e c i a l coat w a s made from aheet i r o n ,

Thia 5. n s t a l l a t f on proved v e r y convenf e n t f o r t h e experiment

,

It i s p a p t i e u l a r l y valuable because e x p e r i men$ s w i t h small q u a n t i t i e s of f u s f on can be c a r r i e d o u t o

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Name of M a t e r i a l 1, Marl 1.96 2, Dolomite 3, Speckled I 4. Sand 0,26 100.63

For our experiments we used a K r y p t o l f u r n a c e ,

The raw materialS t o be used f n a new f a c t o r y f o r t h e p r o d u c t i o n of m i n e r a l wool have been i n v e s t i g a t e d by t h f s method.

Marl, dolomite, dfatomf t e and sand were s u b j e c t e d t o t h e s e i n v e u t i g a t i ons, The chemical composi t f on of t h e components of t h e raw m a t e r i a l 1.3 gfven i n Table 5,

S i x mfxtures were compounded, A l l m i x t u r e s contaf ned a p p r o x i m a t e i y uniform amounts of A1203 and Fe2O3, whf ch p e r m i t t e d t o e s t a b l i s h t h e e f f e c t s produced by CaO and NO on t h e pro-

p e r t i e s of t h e f u s i o n o

The chemical composition of t h e m i x t u r e s a r e compiled i n Table 6,

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Table 7 g i v e s t h e chemical compositions of t h e f u s i o n s and

.of'

t h e modulus s

The mixtures i n t h f s t a b l e a r e subdf vided i n t o two groups, From t h e f f ~ s t group (numbers 6, 4 , 1 ) i t i s p o s s i b l e t o judge t h e e f f e c t of t h e content of CaO on t h e p r o p e r t i e s of t h e fusf on, The second group(nurnbers 1, 3, 2 ) e x p l a f n t h e e f f e c t

TABLE 4

The r e s u l t s of the d e t e r m i n a t i o n of t h e m e l t i n g temper- a t u r e of t h e mfxturea and t h e f l o w a b i l i t y of t h e f u s i o n a r e given i n t a b l e 80

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From a comparison of t h e d a t a given i n t a b l e s 7 and 8, i t

i s e v i d e n t t h a t a n i n c r e a s e I n t h e s o n t e n t of CaO from 30 t o 40$

makes t h e kusi on more f l u i d ; an i n c r e a s e f n t h e content of MgO a l s o makes t h e f u s f on more f l u i d ; however, t h e i n c r e a s e i n t h e q u a n t i t y of MgO i n c r e a s e s t h e temperature of melting, Mixture No, 5 gave t h e most f l u i d f u s i o n with a s u f f i c i e n t l y low tempes- a t u r e of melting,

A mineral wool with t h e f o l l o w f n g p r o p e r t i e s was o b t a i n e d

from mixture NO, 5,

B,

Thickness of f i b r e x maxfmum --lo6

p,

minimum - - l o 2 5

p,

2, The compositi on of the wool by t h e f i b r e t h i ckness ( i n p e r c e n t ) z from 1,25 t o 9,4 JI --30, from g 0 4 t o 19 p--60, from 19 t o PO6 )1

--lo,

3, Length of f i b r e from 0 , s t o

l o o

cm,

A eomparYson of t h e q u a l i t y of t h e o b t a i ned wool wPth t h e s t a n d a r d s p e c i f i c a t f o n s f o r s l a g c o t t o n ( s t a n d a r d 14--3915) shows t h a t t h e o b t a i n e d wool does not s a t f s f y t h i s standard,

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From observatfons during t h e experiment, it i s p o s s i b l e t o con- clude t h a t t h e poor q u a l i t y of t h e wool i s due t o t h e v e r y h i g h v i s c o s i t y of t h e f u s f o n d u r i n g t h e time of i t s atomfzatfon,

The vf s c o s f t y of t h e fusf on can be lowered by t h r e e

met hods :

1, By i n c r e a s i n g t h e r e h e a t i n g temperature of t h e f u s i o n , T h i s could not be done s i n c e t h e experiments were c a r r i e d o u t a t a very hfgh temperatureo

2, By an i n c r e a s e i n t h e content of MgO; t h i s i n c r e a s e was un- d e s i r a b l e s i n c e the fusf on a l r e a d y contained about 8% of MgO and a f u r t h e r a d d i t i o n of MgO would l e a d t o a h i g h e r temperature of melting,

3 , By t h e i n t r o d u c t i o n of f l u x e s which would lower t h e v i s c o s i t y , but which would not i n c r e a s e t h e malting temperature of t h e

mixtureo

Sodium s u l p h a t e i n t h e amount of 6,58$ ( c a l c u l a t e d so a s t o i n t r o d u c e up t o 2% of NaaO i n t o t h e f u s i o n ) was used a s t h e f l u , The changed composition of t h e f u s i o n s due t o t h e addl ti ons of t h e sodfum s u l p h a t e a r e compiled i n Table 9,

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The r e s u l t s of t h e d e t e r m i n a t i o n of t h e m e l t f n g t e m p e r a t u r e s of t h e m i x t u r e s c o r r e c t e d due t o t h e a d d i t i o n of sodium s u l p h a t e , and t h e f l o w a b i l i t i e s of t h e new s e r i e s of f u s f o n s a r e compfled i n t a b l e 10,

TABLE 1 0

b

Noo of t h e f u s f on

The i n t r o d u c t i o n up t o 2% of Na20 i n t o t h e composition of t h e f u s f ons lowers t h e v i s c o s i t y t o a c o n s i d e r a b l e degree, Moreover,

Chemical Compdsition of t h e F u s i o n s ( i n %) Number of t h e Mixture 1 29 3 9 4 ' 50 69

t h e value of t h f s d e c r e a s e i s n o t uniform f o r a l l f u s i o n s . The Si02 i

1'

38,85 2

'

29054 31,34 48060 5 ' 40060 6 56073 Melting Temperature ( i n OC)

-

1390 1200 1100 1160 1100 A1203

-

10046 7010 8,50 9035 8 , 7 0 7035 F l o w a b i l i t y of F u s i o n ( k ) CaO 42,48 43010 45,80 34.39 37.00 29068 Fe203 3,58 lo87 4,40 3040 4,15 2056 Temperature of t h e experiment

No

2,73 15060 7,99 2046 7 , 6 5 l o 9 6 Length (1) of Stream 3 Na2 0 l o g o 2,06 l 0 9 7 l O 8 O l o g o 1 0 7 2 ( i n OC) ( i n m 0 ) c o o l e d m a t e r i a l

7

k

=

l / g

j

Weight (g) of t h e 1400

_-

1400 1400 1400 1400 I ( i n g o )

1

90

-

17 2 89 118 52 1 l 0 2 5 8,OO

_-

i

,

-

I 14,40 11, 95 I 1 l O 7 O 7 , 6 0 9 0 97 11,84

i

8029 6,27

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I n t r o d u c t i o n of Na20 produces t h e g r e a t e s t e f f e c t on f u s i o n s r i c h i n MgO, s i n c e t h e i n t r o d u c t i o n of Na20 i n c r e a s e s t h e l i q u e f y i n g a c t i o n of MgO. If t h e a d d i t i o n of 1.9% Na20 i n t o t h e composition of t h e f u s i o n number 1 i n c r e a s e s i t s f l u i d i t y by 26$, t h e n t h e a d d i t i o n of 1 ~ 9 7 % NaZO i n t o t h e composition of t h e f u s i o n number

3 ( r i c h i n MgO) i n c r e a s e s i t s f l u i d i t y by 73g0 Analogous r e s u l t s a r e observed f o r m i x t u r e number 5 ( c o n t a i n i n g a p p r o x i m a t e l y t h e same amount of MgO a s mixture number 3 ) t h e f l u i d i t y of which was I n c r e a s e d by 7 0 % ~

The m i x t u r e s N o . 1 ~ 5 and 3 p o s s e s s i n g t h e g r e a t e s t f l u i d i t y , were used t o o b t a i n m i n e r a l wool,

The c h a r a c t e r i s t i c s of t h e p r o p e r t i e s of t h i s m i n e r a l wool a r e compiled i n t a b l e llo

(22)

(23)

The l i n e a r v e l o c i t y of t h e atomizing element a t t h e p o i n t s of c o n t a c t of t h e f u s i o n j e t w i t h t h e spokes does n o t exceed 7 0 ~ / s e c . I n i n d u s t r y atomization i s c a r r i e d out by steam, which has a v e l o c i t y a t t h e time of e x i t from t h e b o i l e r of 300 t o 800 1vI/seo, By atom- i z i n g mixture No, 5 w i t h steam, i t i s p o s s i b l e t o o b t a i n

a

wool c o n t a i n i n g a l a r g e r p e r c e n t of f i b r s s having a diameter from 1 t o

We can recommend mixture Noo 5 t o i n d u s t r y , on t h e b a o i s of t h e experiments which we have c a r r i e d o u t o

I n s p i t e of t h e f a c t t h a t mixture NO. 3 produces a c o t t o n which f s more uniform i n q u a l i t y t h a n mixture NO, 5, we can n o t recommend mixture Noo 3 t o i n d u s t r y , s i n c e the f u s i o n has t h e

tendency t o break up i n t o powder upon cooling, This tendency i s

Si02

+

A1203

+

Fe203

q u i t e understandable, s i n c e t h e r a t i o

CaO

+

MgO f s l e s s t h a n u n i t y f o r mixture No, 3,,

Conclusions

A method f o r t h e i n v e s t i g a t i o n of raw m a t e r i a l s t o be used

4n t h e production of mineral wool has been worked out, It was

a l s o p o s s i b l e t o o b t a i n a mineral wool from t h e raw m a t e r i a l s under i n v e s t i g a t i o n and recommend a composition of t h e mixture, Bibliography

l o Canado Min, Metallurg, Bull,, 2, 93 ( 1 9 3 6 ) ~

2, J O T o Thorndyke, UoSoP., 2, 193, 982*

30 UoSoPog 2, 022, 8110

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Ro Rach, T o n f n d u s t r i e Zeitung, 46 (1937),

Do

Lo

Kaufman, Keramfka, 9, 1939,

Khrapkovskf, American Technique and I n d u s t r y , 7, (1945).

Ch, Fo Ramseyer, U,S.P., 2, 193, 9820

Rock P r o d u c t s , 49, 1, 97 (1946)0 P f t and Quarry, 38 1, 107 (1946)0

Mo

G o Cherniak and M o C o Aslanova, Keramika and G l a s s , 4, (1938).

Z o Eo P e r k a l a n d A o C, E p s t e i n , The I n d u s t r y of B u i l d i n g M a t e r f a l s , 48, (1940), M o A o Pavlov, S o v f e t Metallurgy, 3, (1932).

L.

V o Zverev, V i s c o s i t y of S l a g s , U n i t e d T e c h n o l o g i c a l Publf s h e r s (1935), Levinson--Le a s i n g , P e t r o g r a p h y o D i l a k % o r s U , Notes of t h e Union M i n e r a l o g f c a l S o c f e t y , 2nd S e r l e s , P t o 68, 1.

Vo Po Selfvanov, The M e t a l l u r g y of Cast I r o n o

No No

Kurnakov and o t h e r s , Dokladi Akademli Nauk, New S e r i e s ,

111, 30

J, Buss, B r , Po 435, 064,

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