Brick Notes • Brick is made from clay or hale formed, dried and red into durable ceramic product. • 3 ways to form the shape and size of bricks: 1. Extr uded st i! mud" # ma$ority of bricks from this method %. &olded soft mud" 3. 'r y( pr essed • )olour of bricks deri*ed from minerals in the red clay or coatin+ applied before and after rin+ process. • Bricks shrink durin+ manufacturin+ process as *itrication occurs. Bricks will *ary in size due to the manufacturin+ process. hese *ariations are addressed by -& standards. • ðod used to form a brick has a ma$or impact on its texture. and(nished surfaces are typical with molded brick. - *ariety of textures can be achie*ed with extruded brick. • 3 principle forms of clay of similar chemical composition but di!erent physical properties: 1. urfa ce clay s # may be the up thrus ts of olde r depo sits or of more recent sedimentary formations and are found near surface of earth. %. hale s # clays that ha* e been sub$e cted to hi+h pr essur e until they ha*e nearly hardened into slate. 3. /ire clays # clays usually mined at deeper le*els than other clays and ha*e refractory 0ualities. -ll three types of clay are composed of silca and alumina with *aryin+ amounts of metallic oxides. &etallic oxides act as uxes promo tin+ fusion of the particles at lower temperatur es. • Essentially, bricks are produced by mixin+ +round clay with water, formin+ the clay into the desired shape, and dryin+ and rin+. • 2 +eneral phases of manufacturin+: 1. &inin + and stor a+e o f raw mate rials %. r eparin + raw materia ls 3. /ormin+ the bric k # Extrud ed, &olde d or 'ry( r essed 4. 'ryi n+ # %4h t o 45h in 356 ) to %746) 8. / irin+ and co olin+ # rin + for 17h to 47h. )oo lin+ for ma x. 17h in tunnel kiln and 8h to %4h in periodic kiln. 2. 'e(hackin+ and storin+ nished product • 8 sta+es in rin+ phase: 1. / inal dr yin+ 9 %746) %. 'eh ydr ati on 9 146) t o 5%6) 3. ;xi dat ion 9 83 56) to 5%6 ) 4. <i tri ca tio n 9 5=16 ) to 13126) 8. /lash in+ or r educti on ri n+ 9 dec linin+ t emps . • > • > • >
Brick is made from clay or hale formed, dried and fired into
durable ceramic product. 3 ways to form the shape and size of
bricks:1. Extruded (stiff mud) majority of bricks from this
method2. Molded (soft mud)3. Dry-pressed Colour of bricks derived
from minerals in the fired clay or coating applied before and after
firing process. Bricks shrink during manufacturing process as
vitrification occurs. Bricks will vary in size due to the
manufacturing process. These variations are addressed by ASTM
standards. Method used to form a brick has a major impact on its
texture. Sand-finished surfaces are typical with molded brick. A
variety of textures can be achieved with extruded brick. 3
principle forms of clay of similar chemical composition but
different physical properties:1. Surface clays may be the upthrusts
of older deposits or of more recent sedimentary formations and are
found near surface of earth.2. Shales clays that have been
subjected to high pressure until they have nearly hardened into
slate.3. Fire clays clays usually mined at deeper levels than other
clays and have refractory qualities.All three types of clay are
composed of silca and alumina with varying amounts of metallic
oxides. Metallic oxides act as fluxes promoting fusion of the
particles at lower temperatures. Essentially, bricks are produced
by mixing ground clay with water, forming the clay into the desired
shape, and drying and firing. 6 general phases of manufacturing:1.
Mining and storage of raw materials2. Preparing raw materials3.
Forming the brick Extruded, Molded or Dry-Pressed4. Drying 24h to
48h in 38C to 204C5. Firing and cooling firing for 10h to 40h.
Cooling for max. 10h in tunnel kiln and 5h to 24h in periodic
kiln.6. De-hacking and storing finished product 5 stages in firing
phase:1. Final drying @ 204C2. Dehydration @ 149C to 982C3.
Oxidation @ 538C to 982C4. Vitrification @ 871C to 1316C5. Flashing
or reduction firing @ declining temps. X X X X X
