Refractory & general engineering

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Refractory & general engineering

Refractory & general engineering

A material called “refractory” if it is able to withstand a very high flame or temperature, continuously for a long time, without experiencing significant dimensional and property changes, and also resistant to abrasion and corrosion at high temperatures, both by objects solid, liquid and gas.

Refractory definition according to ASTM C 71

That is a non-metallic material with properties and chemical content that can be applied to form a structure or part of a system exposed by an environment of temperatures above 1000 ° F, 811 K, or 538 ° C.

Refractory classification  

  • Classification based on chemical composition contained in the material 

ACIDIC REFRACTORIES

Examples of materials: Alumina, Silica, Alumina silicate, Fire flay bricks

Characteristics:

  • Not easily affected or react with materials that are acidic, but easily affected by basic materials.
  • Material that can react with a combination of Alumina-Silicate, namely hydrofluoric acid, phosphoric acid, and fluorinated gases .
  • In high temperature Acidic Refractories also react with Limes and basic oxides.

BASIC REFRACTORIES

Examples of material: Magnesia, Magnesia Chrome, Dolomite
Characteristics:
  • It doesn’t change by alkaline materials but reacts easily with Aciid materials.

    Many are used in basic areas and slags.

NEUTRAL REFRACTORIES

Examples of material: Pure alumina, Chrome and Carbon

Characteristics:
  • This material tends not to change in acidic or basic conditions.
    Generally used in areas where atmosphere conditions and slags are in an acid or basic state.
  • Material classification based on the production method
  • SHAPPED REFRACTORIES (FIRE BRICKS)
FIRE BRICKS (DENSE FIRE BRICKS) 
  1. Pessed bricks (Standard size & special size)
  2. Precast bricks
  3.  Fused cast bricks

INSULATING FIRE BRICKS

  1. Hot face lining
  2. Back up lining
  • UNSHAPPED REFRACTORIES (MONOLITIC REFRACTORIES)
CASTABLE REFRACTORIES
  1. Dense castable refractories
  2.  Insulating castable refractories

GUNNING CASTABLE REFRACTORIES

  1. Dense gunning castable refractories
  2. Insulating gunning castable refractories
  • PLASTIC REFRACTORIES 
  • SPECIAL CASTABLE FOR REPAIR
  • INJECTION CASTABLES
  • REFRACTORY MORTAR
There are very few references about refractory material that we can find, because this material has never been taught in school or college, except for very few, in this blog I try to summarize the refractory material that I got in my work for at least 2 years this last, namely in the company PT. IDM, which is one of the leading manufacturers and applicators for refractory products in Indonesia.

In general, refractory material is a material or material that can maintain its strength at high temperatures.
Whereas ASTM C71 defines refractory as “a non-metallic material that has chemical and physical properties that make it resistant to conditions above 1,000 ° F (811 K, 538 ° C)”
Refractory materials used in coatings for furnaces, kiln, incinerator and reactor and also used to make crucibles or insenerators.

Materials fire-resistant (refractory)must be resistant to chemical and physical treatment stable at high temperatures. Depending on the operating environment, refractory materials must be resistant to thermal shock, chemically and / or have a certain range of thermal conductivity and coefficient of thermal expansion.
Aluminum oxide (alumina), silicon (silica) and magnesium (magnesium) are the most important materials used in making refractories. Another oxide usually found in refractories is calcium oxide (lime). Fire clays are also widely used in making refractories.
Refractories must be chosen according to the conditions they will face. Some applications require special refractory materials. Zirconia is used when matter must withstand very high temperatures. Silicon carbide and carbon (graphite) are two other refractory materials that are used in some very severe temperature conditions, but they cannot be used in contact with oxygen, because they will oxidize and burn.
Binary compounds such as tungsten carbide or boron nitride can be very fire resistant. Hafnium carbide is the most refractory known binary compound, with a melting point of 3890 ° C. The ternary compound tantalum carbide hafnium has one of the highest melting points of all known compounds (4215 ° C).

Application of refractory and castable stones

Fireproof brick or fire brick is used for applications in combustion chambers or furnaces for boilers, ovens, kilns, dryers, heating furnaces, burners and others.
In the installation of refractory stones requires a clay mortar or fire resistant cement to glue. Whereas in parts that cannot be installed with refractory stones castable is used by casting, for example on the door, the shape of holes, sloping walls.
For a wall area of ​​1 square meter requires a fire-resistant stone:
1. 140 pieces with 230 mm wall thickness,
2. 70 pieces with 115 mm wall thickness,
3. 35 pieces with 65 mm wall thickness.
While the need for mortar is usually 270 kg for the installation of 1000 fireproof stones.

Castable or Fire-resistant Cast Cement serves as patching and / or making printing. Usually used in Boilers, Furnaces, Smelting, Kiln, Dryer, Rotary, Incinerator, etc.

SPECIFICATION

CASTABLE REFRACTORIES
1. Max. Service Temp (Degree):
– TNC-12 = 1050
– TNC-13 = 1200
– TNC-14 = 1350
– TNC-15 = 1400
– TNC-16 = 1500
– TNC-17 = 1650
– TNC-16H = 1500
– TNC -17H = 1700

2. Bulk Density (gr / cm3):
– TNC-12 = 1.8-1.9
– TNC-13 = 1.9-2.0
– TNC-14 = 2.0-2.2
– TNC-15 = 2.2-2.3
– TNC-16 = 2.3-2.4
– TNC-17 = 2.4-2.5
– TNC-16H = 2.1-2.4
– TNC-17H = 2.5-2.7
3. Additional Water (%):
– 12
TNCs – 14-18 – TNC-13 = 14-18
– TNC -14 = 13-18
– TNC-15 = 13-16
– TNC-16 = 12-16
– TNC-17 = 12-16
– TNC-16H = 8-12
– TNC-17H = 5-10
4. Thermal Conductivity (Kcal / mh C)
a. 350 Degree Celsius:
– TNC-12 = 0.48
– TNC-13 = 0.52
– TNC-14 = 0.71
– TNC-15 = 0.74
– TNC-16 = 0.82
– TNC-17 = 0.89
– TNC-16H = 0.80
– TNC-17H = 1.1
b. 450 Degree Celsius:
– TNC-12 = 0.52
– TNC-13 = 0.55
– TNC-14 = 0.76
– TNC-15 = 0.80
– TNC-16 = 0.87
– TNC-17 = 0.92
– TNC-16H = 0.85
– TNC-17H = 1.4
5. Chemical Composition
Al2O3 (%):
– TNC-12 => 28
– TNC-13 => 32
– TNC-14 => 40
– TNC-15 => 44
– TNC-16 => 52
– TNC-17 => 68
– TNC-16H => 50
– TNC-17H => 75
SiO2 (%):
– TNC-12 = <56
– TNC-13 = <52
– TNC-14 = <48
– TNC-15 = <45
– TNC-16 = <30
– TNC-17 = <20
– TNC-16H = <
– TNC-17H = <12

Fire Resistant Cement or Fire Mortar or Mortar is used as adhesive for refractory bricks. Cannot be used as brick acian.SPECIFICATION

– Temp. Max’s work (C):
SK-30 = 1050
SK-32 = 1150
SK-34 = 1300
SK-36 = 1500
SK-38 = 1650
– Requarired Material (kg / 1000 pcs fire brick):
SK-30 = 200-260
SK-32 = 200-260
SK-34 = 200-270
SK-36 = 225-270
SK-38 = 225-270
– Chemical Composition
A12O2 (%)
SK-30 => 25
SK-32 => 30
SK-34 => 40
SK-36 => 50
SK-38 => 60

For other details of our products about fire mortar, it can be opened at the following link this:http://batrefractories.com/semen-tahan-api-atau-refractory-mortar/

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