Foundary Fluxes

8/17/2019 Foundary Fluxes

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FOUNDARY FLUXES

DEFINITION AND CONCEPTa) A fux is a low meltin !oint mate"ial#) $%en %eate& u!' it melts an& (om#ines wit% as%' is(ous slas' san&' metalli(

oxi&es et(*' an& ma+es a fui& an& eas, fowin sla*() T%is sla #ein li%te" (omes on to t%e su"-a(e o- t%e molten metal -"om w%e"e

it (an #e easil, s+imme&' ta!!e& o" "emoe& #e-o"e !ou"in t%e metal into t%e

mol&*&) Sla !"ote(ts molten metal -"om -u"na(e atmos!%e"e*

TYPES OF FLUXES

a) Limestone is use& as fux in (u!ola w%en meltin (ast i"on*#) So&ium (a"#onate w%en use& wit% limestone as a fux in (u!ola ies "ise to

a sla w%i(% (an "emoe sul!%u" -"om (ast i"on*() Nit"oen' .elium' an& (%lo"ine a"e use& as aseous fuxes in aluminium

-oun&", -o" "emoin &issole& %,&"oen an& t%e ent"a!!e& &"oss* D"oss

(onsists o- aluminium' manesium' sili(on' (o!!e" et(*' w%i(% ma, foat on

t%e su"-a(e o- molten aluminium o" sin+' &e!en&in u!on t%ei" s!e(i/(

"ait,*

Fluxes se!a"ate molten metal an& &"oss*

0esi&es aseous fuxes' soli& fuxes o- some (om!ositions o- (%lo"i&es o-

aluminium an& 1in( a"e also em!lo,e& to se!a"ate metal an& &"oss*Soli& fuxes a"e eas, to use as (om!a"e& to aseous ones*

&) Flux use& -o" meltin manesium allo,s (onsists o- 2Cl' 3O' 3Cl4' CaF4'

0aCl4' an& 3nCl4*#esi&es ot%e" -un(tions' fuxes !"eent t%e #u"nin o-

manesium allo,s* Nit"oen ma, #e #u##le& slowl, t%"ou% t%e molten

manesium -o" "emoin %,&"oen*e) In (o!!e" allo, -oun&", !"a(ti(e' (%a"(oal is use& to !"eent t%e molten metal

-"om #ein oxi&i1e&' an& some (omme"(iall, aaila#le fuxes ma, #e

em!lo,e& to (leanse t%e metal i*e* to se!a"ate it -"om &"oss*



Re-"a(to"iesINTRODUCTION5

A) Re-"a(to"ies a"e %eat "esistant mate"ials*0) T%e, (an wit%stan& %i% tem!e"atu"es wit%out #ein -use&*C) C"u(i#les an& -u"na(es si&es an& #ottoms (ontainin molten metal a"e ma&e

u! o- "e-"a(to"ies*D) Re-"a(to"ies a"e use& as la&les -o" !ou"in metal into t%e mol&

E) Re-"a(to"ies (onstitute -u"na(e walls an& "oo- an& t%us minimi1in %eatlosses*

F) T%e main (onstituents o- -oun&", "e-"a(to"ies a"e 3O' SiO4' Al4O6 an& t%ei"

mixtu"es*7) T%e newe" "e-"a(to", mate"ials a"e manesia an& 1i"(onia*

P"o!e"ties5

A) "e-"a(tie s%oul& #e %eat' (o""osion an& a#"asion "esistant0) T%e, s%oul& !ossess %i% -usion tem!e"atu"es*C) T%e, s%oul& !ossess low t%e"mal (oe8(ient o- ex!ansion*

D) T%e, s%oul& not %ae (%emi(al a8nit, wit% t%e molten metal t%e, %ol&*E) T%e, s%oul& #e a#le to wit%stan& %i% tem!e"atu"es an& !"essu"es 9&ue to

t%e wei%t o- t%e molten (%a"e*)F) T%e, s%oul& !ossess %eat an& ele(t"i( insulatin !"o!e"ties*

Classi/(ation5

Re-"a(tie ma, #e "ou!e& into -ollowin (ateo"ies*

:* A(i& "e-"a(to"ies

4* 0asi( "e-"a(to"ies6* Neut"al "e-"a(to"ies

A(i& "e-"a(to"ies5

T,!e

a!!"ox* -usion tem!e"atu"e9C):* Sili(a

:;<<



4* Aluminium sili(a9=>?Al4o6@=? SIo4)

:;B<6* Alumina 9Al4o6)

4<<=* Silimanite 9>6?Al4o6@6;?Sio4)

:<<

0asi( "e-"a(to"ies

:* 3anesia

4B<<0auxite an& &olomite a"e also #asi( "e-"a(tie

Neut"al "e-"a(to"ies

:* C%"omite

4:B<

4* 7"a!%ite6<<<

Re-"a(to", mate"ials5:* Re-"a(tie a"e o#taine& -"om o"es o- sili(a o" t%ose o- sili(a an&

alumina*4* A-te" minin o" (%emi(al !"o&u(tion an& (ali(inin' "e-"a(to", mate"ials

a"e ("us%e&' "oun& an& !"e!a"e& to si1e* T%e, a"e t%en mixe& wit%

ot%e" mate"ials an& s%a!e& as #"i(+s* 0"i(+s a"e use& -o" lininmeltin

an& ot%e" -u"na(es* 0"i(+s o- a(i&' #asi( an& neut"al "e-"a(to"ies an& o- &ie"ent s%a!es a"e aaila#le -o" -u"na(e (onst"u(tion*6* 0"i(+s &u"in (onst"u(tion wo"+ a"e #on&e& an& (us%ione& wit% t%e

%el! o- a mo"ta" (onsistin o- (%"ome' sili(on (a"#i&e' sili(a an&

alumina* 3o"ta" ma, #e s!e(i/e& #, t%e #"i(+ manu-a(tu"e"*=* 0"i(+ wo"+ ma, #e (oate& wit% t%in mo"ta" -o" -u"t%e" !"ote(tin t%e

same &u"in -u"na(e o!e"ation*





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Foundary Fluxes