CERAMIC INDUSTRY Flashcards
ONE OF THE MAIN TYPE OF MATERIALS USED IN THE
DIFFERENT FIELDS OF ENGINEERING ALONGSIDE METAL POLYMER AND COMPOSITE MATERIALS.
CERAMICS
A COMPOUND THAT PRIMARILY CONSIST OF METALLIC AND NONMETALLIC ELEMENTS.
CERAMICS
SOMETIMES ALSO CALLED THE CLAY PRODUCTS
OR SILICATE INDUSTRIES.
CERAMIC INDUSTRIES
ALWAYS HAVE SILICATES AS THEIR FINISHED
MATERIAL IN A VARIETY OF PRODUCTIONS.
CERAMIC INDUSTRY
THE OLDEST KNOWN CERAMIC ARTIFACT IS
DATED AS EARLY AS 28,000 BC, DURING THE
LATE PALEOLITHIC PERIOD (CAVEMAN)
OLDEST KNOWN CERAMIC ARTIFACT
STATUETTE OF A WOMAN NAMED VENUS OF DOLNI VESTONICE
IN THIS LOCATION (CZECH REPUBLIC),
HUNDREDS OF CLAY FIGURINES
REPRESENTING________ WERE
ALSO UNCOVERED NEAR THE REMAINS OF A
HORSESHOE-SHAPED KILN.
ICE AGE ANIMALS
DATING BACK TO
15,000 B.C. WHAT WERE ALSO FOUND AND
RECORDED.
BURNT CLAYWARES
-WHO BECAME
ENGAGED IN THE ART OF CERAMICS 10
CENTURIES LATER (5000 B.C.)
CHINESE AND THE EGYPTIANS
ART OF CERAMICS BECAME A HOBBY FOR
AMERICAN MEN AND WOMEN
MUSEUMS NOWADAYS CONTAIN
CERAMIC MATERIALS, AS A
RECORD OF MAN’S CULTURE,
MANY SIGNIFICANT NEW
DEVELOPMENTS HAVE TAKEN PLACE IN
1920
(RESISTANT
TO THE CHANGES IN THE TEMPERATURE),
PURE OXIDE REFRACTORIES
EXAMPLE OF PURE OXIDE REFRACTORY
ALUMINUM OXIDE
1925 THE PRODUCTION OF COMMON BRICKS REACHED
7.6B
IN 1924, FACE BRICKS ATTAINED HOW MUCH?
2.5 B
TOP 6 CHIEF MANUFACTURING STATES FOR CERAMIC INDUSTRIES
OHIO
PENNSYLVANIA
NEW HERSEY
WEST VIRGINIA
CALIFORNIA
MISSOURI
THREE MAIN RAW MATERIALS FOR CERAMIC
INDUSTRY:
CLAY
FELDSPAR (SPAR)
SAND (FLINT)
IMPURE HYDRATED ALUMINUM
SILICATES THAT HAVE RESULTED FROM THE
WEATHERING OF IGNEOUS ROCKS
CLAY
ARE PRODUCED THROUGH THE
HYDROLYSIS OF WEATHERING REACTIONS
OF IGNEOUS ROCKS
CLAY
CLAY VARIES DEPENDING ON THE
CONTENT OF THE CLAY MINERAL.
TRUE
THE DIFFERENT CLAY MINERALS
KAOLINITE 122 WHITE
BEIDELLITE 131 YELLOWISH
MONTMORILLONITE 141 PINKISH
HALLOYSITE 123 BLUISH
ARE PLASTIC AND MOLDABLE WHEN SUFFICIENTLY FINELY PULVERIZED.
CLAY
WHEN CLAY IS BEING AIR-DRIED.
WET, RIGID
CLAY WHEN FIRED AT A SUITABLY HIGH TEMPERATURE.
VITREOUS
SAME CLAY BODIES “MATURE” AT DIFFERENT TEMPERATURES
FALSE
A TERM USED TO IDENTIFY THAT AT A SPECIFIC TEMPERATURE, CLAY CAN BE
FORMULATED TO PRODUCE NEW PRODUCTS.
MATURE
THE HIGHER A
CLAY BODY IS DESIGNED TO FIRE, THE MORE VITREOUS IT IS.
TRUE
A VITREOUS CLAY IS MORE RESISTANT TO WATER ABSORPTION, WHICH IN TURN
CAN PREVENT DEFECTS AND CRACKING FROM HAPPENING.
TRUE
IS A PROPERTY OF CLAY THAT ALLOWS IT TO CHANGE ITS SHAPE WITHOUT
RUPTURING EVEN AFTER PUTTING A GREATER AMOUNT OF FORCE .
PLASTICITY
THE MOST BASIC CLAY MINERAL USED IN THE
CERAMIC INDUSTRY
KAOLINITE
IT IS THE MOST
ABUNNDANT CLAY MINERAL OF ALL DIFFERENT TYPES
(WIDELY USED IN POTTERY AS WELL).
KAOLINITE
ARE BASED ON
MONTMORILLONITE CLAYS, THEY ARE USED TO SOME
EXTENT WHERE VERY HIGH PLASTICITY IS DESIRED.
BENTONITE CLAYS
CLAYS DONT VARY AND HAVE A LOT OF IMPURITIES PRESENT.
FALSE
WAY FOR US TO INCREASE THE CONTENT OF CLAY MINERALS IN
CLAYS
BENEFICIATION
INCREASE CONTENT OF CLAY MINERALS WHILE DECREASING THE CONTENT OF QUARTZ
BENEFICIATION
ALSO HELPS TO ACHIEVE THE REQUIRED
PARTICULAR SIZE AND SIZE DISTRIBUTION OF RAW MATERIALS.
BENEFICITION
MAJORITY OF THE PROCESS OF BENEFICIATION OF CLAY CONSISTS OF
UNIT OPERATIONS
TRUE
SIZE SEPARATION IS DONE BY
SCREENING OR SELECTIVE SETTLING FILTRATION OR DRYING
ARE ADDED AS THE APPROPRIATE
ADDITIONAL AGENTS USED TO CONTROL THE COLLOIDAL PROPERTIES OF
CLAY.
SODIUM SILICATE AND ALUMINUM
A GROUP OF ALUMINOSILICATE MINERALS
THAT ALSO CONTAINS CALCIUM, SODIUM
AND POTASSIUM.
FELDSPAR
MAKES UP MORE THAN HALF OF THE EARTH’S
CRUST.
FELDSPAR
MOST COMMON MINERAL IN THE EARTH’S
CRUST.
FELDSPAR
THE 3 COMMON TYPES OF FELDSPAR USED IN THE
CERAMIC INDUSTRY.
POTASH
SODA
LIME OR ANORTHITE
MOST COMMON TYPE OF FELSPAR
POTASH
IS OF GREAT IMPORTANCE AS A FLUXING CONSTITUENT IN CERAMIC
FORMULAS
FELDSPAR
THE PRESENCE OF FLUXES TENDS TO LOWER THE TEMPERATURE OF THE FORMATION
OF MULLITE AND INCREASES THE ATTAINMENT OF THE
EQUILIBRIUM CONDITIONS DURING THE MANUFACTURING PROCESS.
true
(FORMS WHEN CLAY MINERALS ARE IN CONTANCT WITH EACH OTHER
AND UNDERGOES METAMORPHISM)
mullite
fluxing agent
feldspar
PROMOTES VITRIFICATION/ INCREASES THE
VITREOUS PROPERTY OF CLAY.
fluxing agent
PROMOTES VITRIFICATION/ INCREASES THE
VITREOUS PROPERTY OF CLAY.
fluxing agent
AS it MELTS AT LOWER TEMPERATURES, IT FORMS A GLASSY PHASE
CONDITION WHICH BONDS THE CERAMIC BODY AND FORMS THE BASIS OF THE CERAMIC
MATERIAL.
GLAZE
A TYPE OF MINERAL THAT NATURALLY CONSIST OF SILICA/ QUARTZ OR SIO2.
SAND
A SAND WITH______ SHOULD BE CHOSEN FOR THE
MANUFACTURING OF LIGHT-COLORED CERAMIC PRODUCTS.
A LOW IRON CONTENT
FUSIBILITY OF KAOLINITE AND QUARTZ
REFRACTORY
FUSIBILITY OF FELDSPAR
EASILY FUSIBLE BINDER
HEATING TO FIRING
TEMPERATURES.
THESE TEMPERATURES MAY BE AS LOW
AS ____ TO AS HIGH AS ___
700°C
1300 TO 1400 C.
DEHYDRATION IS ALSO CALLED
CHEMICAL WATER SMOKING
DEHYDRATION TEMPERATURE
150 TO 650
CALCINATION TEMP
600 TO 900
OXIDATION OF FERROUS IRON AND ORGANIC MATTER
350 TO 900
SILICATE FORMATION TEMP
900 AND ABOVE
THE DEGREE OF REFRACTORINESS
OF A GIVEN PRODUCT IS DETERMINED BY THE
RELATIVE QUANTITIES OF ___________
REFRACTORY
OXIDES AND FLUXING OXIDES.
THE PRINCIPAL REFRACTORY OXIDES:
SIO2, AL2O3, CAO, MGO , ZRO2, TIO2,
CR2O3, BEO
THE PRINCIPAL FLUXING OXIDES:
NA2O,
K2O, B2O3, SNO2 AND SOME FLUORIDES.
THE MOST ESSENTIAL INGREDIENT OF
ALL MATERIALS IS
CLAY
BYPRODUCTS FROM HYDRATION OF CLAY
AMORPHOUS MIXTURE
OF ALUMINA AND SILICA.
A LARGE PROPORTION OF THE ALUMINA CAN
BE EXTRACTED WITH ________ AT THIS STAGE.
HYDROCHLORIC ACID
AS THE TEMPERATURE OF THE
AMORPHOUS ALUMINA (KAOLIN)
CHANGES TO 940 C, IT FORMS A
CRYSTALLINE FORM CALLED
“GAMMA
ALUMINA”
AT ABOUT 1000 C, THE ALUMINA AND
SILICA COMBINE TO FORM
MULLITE
AS THE TEMPERATURE EXCEEDS TO MORE
THAN 1000 C, THE MULLITE IS
CONVERTED TO A CRYSTALLINE FORM
CALLED
CRISTOBALITE
VARIOUS SILICATES AND ALUMINATES OF CALCIUM, MAGNESIUM, AND
POSSIBLY THE ALKALI METALS MIGHT BE PRESENT IN THE FINAL CERAMIC PRODUCT
TRUE
THE VITREOUS PHASE IMPARTS DESIRABLE PROPERTIES TO SOME
CERAMIC BODIES, LIKE
ACTING AS A BOND
IMPART TRANSLUCENCY IN CHINAWARE
THE DEGREE
OF VITRIFICATION DEPENDS UPON
THE FOLLOWING FACTORS:
RELATIVE AMOUNTS OF REFRACTORY
AND FLUXING OXIDES IN THE
COMPOSITION
THE TEMPERATURE
THE TIME OF HEATING
VARYING AMOUNT OF FLUXES, HEAT MODERATELY HIGH AND VARYING VITRIFICATION
WHITEWARES
ABUNDANT FLUXES, HEAT AT LOW TEMP, LITTLE VITIRFICATION
HEAVY CLAY PRODUCTS
LITTLE FLUXES, HIGH HEAT TEMP, LITTLE VITIRFIcation
refractories
moderate flux, heat at high temp, complete vitri
glass
very abundant flux, heat at moderate, complete vitri
enamels
TERM FOR CERAMIC
PRODUCTS WHICH ARE USUALLY WHITE
AND OF FINE TEXTURE.
whitewares
SELECTED GRADES OF CLAY
BONDED TOGETHER WITH VARYING
AMOUNTS OF FLUXES.
whitewares
SOMETIMES CALLED SEMI-VITREOUS DINNERWARE, WHICH ARE POROUS AND
NON-TRANSLUCENT WITH A SOFT GLAZE.
earthware
VITRIFIED TRANSLUCENT WARE WITH A MEDIUM GLAZE THAT CAN RESIST
ABRASION TO A DEGREE AND USED FOR NONTECHNICAL purposes
chinaware
VITRIFIED
TRANSLUCENT WARE WITH A HARD GLAZE, AND CAN RESIST ABRASION TO
THE MAXIMUM DEGREE.
porcelain
FORMERLY MADE FROM CLAY, USUALLY POROUS; HENCE, HAS VITREOUS
COMPOSITION, PREFIRED AND SIZED VITREOUS GROG IS SOMETIMES INCLUDED
WITH THE TRIAXIAL COMPOSITION.
sanitary ware
ONE OF THE OLDEST OF CERAMIC WARES, WAS IN USE LONG BEFORE
PORCELAIN WAS DEVELOPED, REGARDED AS A CRUDE PORCELAIN MADE FROM
A POORER GRADE OF NOT CAREFULLY FABRICATED RAW MATERIALS.
stoneware
CLASSIFIED AS FLOOR TILES, RESISTANT TO ABRASION, IMPERVIOUS TO
STAIN PENETRATIO, MAY BE GLAZED OR UNGLAZED, ALSO USED AS WALL TILES
WHICH HAVE A HARD, PERMANENT SURFACE AND COME IN A VARIETY OF COLORS
AND TEXTURES.
whiteware tiles
CLASSIFIED AS FLOOR TILES, RESISTANT TO ABRASION, IMPERVIOUS TO
STAIN PENETRATIO, MAY BE GLAZED OR UNGLAZED, ALSO USED AS WALL TILES
WHICH HAVE A HARD, PERMANENT SURFACE AND COME IN A VARIETY OF COLORS
AND TEXTURES.
whiteware tiles
USED FOR PRODUCTION OF FINE-GRAINED
HIGHLY GLAZED INSULATORS FOR HIGH-
VOLTAGE SERVICE.
wet process porcelain
PROCESS EMPLOYED FOR RAPID PRODUCTION
OF MORE OPEN-TEXTURED LOW-VOLTAGE
PIECES.
dry process porce
NECESSARY FOR THE MAKING OF PIECES THAT
ARE EITHER TOO LARGE OR TOO INTRICATE
FOR THE OTHER TWO METHODS.
cast porce
THE PRODUCTION OF TABLEWARE CONSISTS
OF MORE COMPLICATED PROCEDURES THAN
THE PRODUCTION OF PORCELAIN.
true
porcelain are shaped by
throwing on the pooter’s wheel
cast from the cast slip
MASS PRODUCTION OF SIMPLE ROUND OBJECTS LIKE
CUPS, SAUCERS, OR PLATES, IS CARRIED OUT
ECONOMICALLY BY
jigging
THE PLASTIC CLAY IS
PRESSED INTO OR ON A SINGLE REVOLVING MOLD.
jigging
THE PROCESS OF VITRIFICATION FOR THE PRODUCTION
OF PORCELAIN IS DONE THROUGH A
one fire process
the only unit process in the production of porce
(vitirification)
IS ALWAYS IMPORTANT IN THE
PRODUCTION OF WHITEWARES.
glazing
IS A THIN COATING OF GLASS THAT
IS MELTED AND IS APPLIED THE SURFACE OF
THE POROUS CERAMIC WARE.
glaze
glazing naturally contains two ingre.
refractory mat and fluxes
IS THE TECHNICAL TERM FOR THE FIRING OF
THE GLAZE INSIDE THE KILN.
glost firing
LARGE SHAPES SHOULD BE PACKED IN THE
CENTER OF THE KILN TO AVOID UNEVEN
HEATING AND SHOULD BE FIRED MORE
SLOWLY THAN SMALL ONES.
true
earthenware should be glazed between
1050 and 1100
stoneware should be glazed between
1250 and 1300
LOW-COST BUT VERY DURABLE PRODUCTS.
heavy clay products
BRICK, FACE BRICK, TERRA COTTA,
SEWER PIPE, AND DRAIN TILE, ARE FREQUENTLY
MANUFACTURED FROM THE
CHEAPEST OF
COMMON CLAYS WITH OR WITHOUT ANY
GLAZING.
PROCESS OF GLAZING IN SEWER PIPE
AND DRAIN TILE BY THROWING SALT UPON
THE KILN FIRE FOR IT TO REACT AND FORM THE
FUSIBLE COATING OR THE GLAZE.
salt glaze
ONE OF THE MOST IMPORTANT OF CLAY
PRODUCTS IS THE
building brick
ARE THE STANDARD BRICK TYPE AND THE
MOST ABUNDANTLY USED BUILDING
MATERIAL IN MODERN CONSTRUCTION.
common bricks
TENDS TO HAVE A MORE AESTHETICALLY
PLEASING APPEARANCE IN COMPARISON
WITH A COMMON BRIC, AS THEY ARE MORE
UNIFORM IN COLOR AND SMOOTHER IN
TEXTURE THAN THE COMMON BRICK.
face brick
(MOST USED CLAY FOR BOTH
COMMON AND FACE BRICK)
red burning clay
THree RAW MATERIALS FOR BUILDING BRICKS
red
white
budd
FREEDOM FROM WARPING, ABSENCE OF SOLUBLE SALTS,
SUFFICIENT HARDNESS WHEN BURNED AT A MODERATE
TEMPERATURE, AND GENERAL UNIFORMITY IN COLOR
UPON BURNING.
face brick
CONSIST OF MOLDING THE CLAY MIXTURE CONTAINING 20 TO 30 PERCENT WATER IN
MOLDS COATED WITH A THIN LAYER OF EITHER SAND OR WATER TO PREVENT STICKING.
SOFT-MUD PROCEDURE
USUALLY MUCH EMPLOYED FOR FIREBRICK AND IS THE ANCIENT METHOD FOR MAKING
BUILDING BRICKS.
SOFT-MUD PROCEDURE
THE CLAY IS JUST WET ENOUGH (12 TO 15 PER CENT) TO STICK TOGETHER WHEN WORKING.
THE CLAY IS FORCED OUT THROUGH A DIE IN A SCREW OR AUGER MACHINE (DRILLER)
STIFF-MUD PROCEDURE
THE WATER CONTENT IS FROM 4 TO 7 PERCENT (USUALLY THE “AS-IS” CONDITION) WHICH
MAKES THE CLAY RELATIVELY NONPLASTIC.
dry process
THE BRICK UNIT in dry process IS MOLDED AT PRESSURES AROUND
5 TONS PER SQ.
THE GREATER PERCENTAGE OF CLAY WARE IS MADE BY
STIFF-MUD PROCESS.
THE PROCESS OF REMOVING AIR FROM THE PUG MILL.
de-airing
NOT ONLY ENSURES A MORE UNIFORM SHAPE BUT OVERCOMES THE
INTERNAL STRESSES SET UP BY THE EXTRUSION IN THE SCREW.
repressing
THESE MOLDED BRICKS MAY BE STACKED_____ FT. HIGH WITHOUT DAMAGE BEFORE BEING
DRIED.
6 TO 10
REFER TO MATERIALS
WHICH ARE USED TO WITHSTAND THE
THERMAL, CHEMICAL, AND PHYSICAL
EFFECTS THAT ARE PRESENT IN FURNACE
PROCEDURES.
REFRACTORIES
REFRACTORIES CAN BE LABELED AS
ACID, BASIC,
AND NEUTRAL.
SEVERAL TYPES OF REFRACTORIES ARE REQUIRED FOR THE
CONSTRUCTION OF A _______
SINGLE FURNACE,
SILICA BRICKS ARE
ACID
-MAGNESITE BRICKS ARE
STRONGLY BASIC
-FIRE-CLAY BRICKS
NEUTRAL GROUP
-IT IS USUALLY UNADVISABLE TO EMPLOY AN ACID BRICK IN CONTACT WITH
AN ALKALINE PRODUCT OR VICE VERSA
TRUE
THE QUALITY OR DEGREE OF HAVING MINUTE SPACES OR HOLES THROUGH WHICH
LIQUID OR AIR MAY PASS.
POROSITY
HIGHER THE POROSITY OF THE BRICK THE MORE EASILY IT IS
PENETRATED BY MOLTEN FLUXES AND GASSES.
TRUE
-FOR A GIVEN CLASS OF BRICK, THOSE WITH THE LOWEST POROSITY HAVE THE
GREATEST STRENGTH, THERMAL CONDUCTIVITY, AND HEAT CAPACITY
TRUE
THE POINT WHERE THE MOLECULES HOLDING THEIR BONDS TOGETHER BREAK APART
AND FORM A LIQUID.
FUSION POINT OR MELTING POINT
IT MEASURE HEAT-WORK, THE EFFECT OF TIME, AND
TEMPERATURE.
PYROMETRIC CONES
A FRACTURING OF A REFRACTORY BRICK OR BLOCK DUE TO UNEVEN HEAT
STRESSES OR COMPRESSION CAUSED BY HEAT.
SPALLING
-REFRACTORIES USUALLY EXPAND WHEN HEATED
TRUE
-THOSE THAT UNDERGO THE GREATEST EXPANSION AT THE
LEAST UNIFORM RATE ARE MOST SUSCEPTIBLE TO SPALLING
WHEN SUBJECTED TO RAPID COOLING AND HEATING
TRUE
RESISTANCE TO ABRASION OR EROSION
STRENGTH
USUALLY ONLY HAS A SLIGHT BEARING ON
STRENGTH AT HIGH TEMPERATURES.
COLD STRENGTH
THE COMPRESSIVE OR FLEXURAL STRENGTH
DETERMINED PRIOR TO FIRING.
COLD STRENGTH:
BRICKS WITH THE LOWEST THERMAL EXPANSION AND COARSEST
TEXTURE ARE THE MOST RESISTANT TO RAPID THERMAL CHANGES AND
DEVELOP LESS STRAIN.
TRUE
-THE DENSEST AND LEAST POROUS BRICKS HAVE THE HIGHEST
THERMAL CONDUCTIVITY
TRUE
FURNACE HEAT CAPACITY DEPENDS UPON THE FOLLOWING PROPERTIES OF THE REFRACTORY:
A) THE THERMAL CONDUCTIVITY,
B) THE SPECIFIC HEAT,
C) THE SPECIFIC GRAVITY
THE LOW QUANTITY OF HEAT ABSORBED BY LIGHTWEIGHT BRICK WORKS AS AN
ADVANTAGE WHEN FURNACES ARE OPERATED INTERMITTENTLY,
TRUE
-USUALLY, THE MOST IMPORTANT SINGLE PROPERTY TO PRODUCE IN
MANUFACTURE IS ,
HIGH BULK DENSITY
FOR INSULATING REFRACTORIES, A POROUS STRUCTURE IS REQUIRED, WHICH MEANS
LOW DENSITY.
TRUE
A MIXTURE IN WHICH THE PROPORTION OF COARSE AND FINE
PARTICLES IS ABOUT
55: 45,
REAL FUNCTION OF MIXING IS THE DISTRIBUTION OF THE PLASTIC MATERIAL
SO AS TO THOROUGHLY COAT THE NONPLASTIC CONSTITUENTS.
TRUE
A METHOD THAT IS PARTICULARLY SUITED FOR BATCHES THAT CONSISTS
PRIMARILY OF NONPLASTIC MATERIALS.
DRY-PRESS METHOD OF MOLDING
IS USED TO REMOVE THE MOISTURE ADDED BEFORE MOLDING TO
DEVELOP PLASTICITY.
DRYING
-THE ELIMINATION OF WATER LEAVES VOIDS AND CAUSES HIGH SHRINKAGE
AND INTERNAL STRAINS.
TRUE
-TWO IMPORTANT THINGS TAKE PLACE DURING BURNING:
THE DEVELOPMENT OF A PERMANENT BOND BY PARTIAL VITRIFICATION OF
THE MIX,
2) THE DEVELOPMENT OF STABLE MINERAL FORMS FOR FUTURE SERVICE,
CHANGES THAT TAKE PLACE DURING BURNING ARE
HYDRATION
CALCINATION
OXIDATION
DURING BURNING, VOLUME MAY SHRINK AS MUCH AS HOW MANY PERCENT?
30
PERCENT
THIS
SHRINKAGE MAY BE ELIMINATED DURING BURNING BY _________
PRESTABILIZATION OF THE MATERIALS USED.
PERCENTAGE OF NON BASIC REFRACTORIES
95%
ARE THE MOST WIDELY USED OF ALL AVAILABLE REFRACTORY MATERIALS,
SINCE THEY ARE WELL SUITED FOR A VARIETY OF APPLICATIONS.
FIRECLAY
ARE THE LARGEST CONSUMERS OF REFRACTORIES FOR THE
LININGS OF BLAST FURNACES, STOVES, OPEN HEARTHS, AND OTHER FURNACES.
STEEL INDUSTRIES
CONTAINS APPROXIMATELY 95 TO 96% SIO2 AND ABOUT 2% LIME
ADDED DURING GRINDING TO FURNISH THE BOND.
SILICA BRICK
THEY HAVE A VERY HOMOGENEOUS TEXTURE, ARE FREE FROM AIR
POCKETS AND MOLDING DEFECTS, AND POSSESS LOW POROSITY.
SILICA BRICK
THE IMPORTANT BASIC BRICKS ARE MADE FROM
MAGNESIA. CHROMITE. AND FORSTERITE.
TRUE
ARE MADE FROM DOMESTIC MAGNESITES OR MAGNESIA
EXTRACTED FROM BRINES
-MAGNESIA REFRACTORIES
THE MOST STABLE SILICATE AT HIGH TEMPERATURES.
FORSTERITE,
ARE MADE FROM NATURALLY
POROUS DIATOMACEOUS EARTH,
BACKING REFRACTORY BRICKS
, ARE SIMILAR IN COMPOSITION TO HEAVY BRICKS AND
OWE THEIR INSULATING VALUE TO THE METHOD OF MANUFACTURE.
LIGHTWEIGHT REFRACTORIES
KNOWN TO HAVE GOOD:
-ALKALI CORROSION RESISTANCE,
-RESISTANCE TO THERMAL LOAD CAN WITHSTAND UP TO 1400C
-OXIDATION RESISTANCE,
-WEAR RESISTANCE,
-HIGH THERMAL CONDUCTIVITY,
-THERMAL SHOCK RESISTANCE
- EXTREMELY LOW ELECTRICAL CONDUCTIVITY.
-ABRASION AND SPALLING.
SILICON CARBIDE
SILICON CARBIDE’S ABILITY TO ABSORB AND RELEASE HEAT RAPIDLY AND THEIR RESISTANCE TO
SPALLING UNDER REPEATED TEMPERATURE CHANGES MAKE THEM DESIRABLE FOR
_____________
RECUPERATORS.
-LIGHT WEIGHT (REDUCE FURNACE LOAD AND EXTEND FURNACE LIFE);
-LOW HEAT CAPACITY (LESS HEAT ABSORPTION AND RAPID TEMPERATURE RISE);
-LOW THERMAL CONDUCTIVITY (LESS HEAT LOSS);
-SIMPLE CONSTRUCTION (NO NEED TO LEAVE EXPANSION JOINTS);
-WIDE RANGE OF USE;
-THERMAL SHOCK RESISTANCE;
-RESISTANCE TO MECHANICAL VIBRATION (WITH FLEXIBILITY AND ELASTICITY);
-GOOD SOUND INSULATION PERFORMANCE (REDUCE NOISE POLLUTION);
ALUMINUM SILICATE
ALSO KNOWN AS “PORCELAIN
ENAMEL”
VITREOUS ENAMEL
IS A SMOOTH, GLASSY, AND
DURABLE SURFACE THAT IS FUSED AT
TEMPERATURES HIGHER THAN 800 C
VITREOUS ENAMEL
THE VITREOUS ENAMEL PROCESS STARTS
WITH SMALL PIECES OF GLASS CALLED
“FRIT”
COLOURED OXIDE IS ALSO CALLED ?
(PIGMENT)
ACTS AS THE
GRINDING AND MIXING
MECHANISM IN VITEROUS ENAMEL PRODUCTION UNTIL THE ENAMEL REACHES A LIQUID STATE
ROTATING BARREL
THIS LIQUID ENAMEL
COATING CAN THEN BE APPLIED TO
A SUBSTRATE SUCH AS
STEEL AND CAST IRON
TO CREATE A SMOOTH FINISH IN COATING OF ENAMEL TO A SUBSTRATE, USE WHAT?
A SPRAY GUN
