Cement Technology Course

Prepared and Presented By:

Dr. Abdel Monem Soltan

E-mail address: abdelmonemsoltan@gmail.com

Cement Technology Course Outline

Building Material
-History
-Importance
-Types

Introduction to Cement

-Definition
-Raw Material
-Raw Material Exploration Methods
-Quarrying Processes
-Grinding Processes
-Blending Processes

Limestone Characterization

-Acid Etching
-Petrography (microstructure)
-Classification – Mineralogy
-Chemistry

Argillaceous Rocks Characterization

-Size Analysis
-tructure
– Mineralogy
-Chemistry

Raw Mix Design

-Impact of Raw Material physical properties on processing
-The material included in the cement industry
-Check-list for potential cement raw materials (mineralogical)
-Check-list for potential cement raw material (chemical) -Deleterious constituents in cement raw materials
-Raw mix design
-Raw mix moduli “ratios”
-Principles of clinker manufacture

Firing Reactions and Mineralogical Transformations
-Firing Kilns
-Mineralogical Transformations along Dehydration Stage
-Mineralogical Transformations along Calcination Stage
-Mineralogical Transformations along Clinkering Stage
-Mineralogical Transformations along Cooling Stage
-Clinker Formation and Mineralogy
-Clinker Grinding and Gypsum Addition

Cement Hydration

-Hydration of Belite
-Hydration of Alite
-Hydration of Tri-calcium Aluminate
-Hydration of Ferrite
-Hydration of Portland Cement
-Role of Gypsum

Cement Types

-Gypsum Plasters
-Limes
-Portland Cement
-White Cement

Lime

-Definition
-Types
-Raw Material Characterization
-Raw Material Chemical Composition

Impact of Limestone Petrography
-Types of Limestones
-Petrography of Limestones
-Thermal Decomposition of Limestones
-Allochem Types and Role
-Orthochem Types and Role
-Grain Size and Role
-Roundness Classes and Role
-Porosity Types and Role
-Petrographic Modeling for Lime Production

Cement

A mixture of compounds made from burning limestone and
clay together at very high temperatures ranging from 1400 to
1600 ºC

Concrete

A composite material made up of a filler (aggregate) and a
binder (cement). The binder “glues” the filler together to
form a synthetic conglomerate

Aggregate

Solid bodies held together by the cement

Portland Cement Raw Materials

Cement Manufacture

Limestone Quarry:Limestone intercalated by marls and or shale

Explosives are used to get limestone boulders

Crushing Process

The limestone boulders are crushed by different types of crushers

Mixing Process (Raw Mix Design)

Raw Material Characterization

Initial Homogenization

Storage of Raw Mix

Grinding the Raw Mix

Firing the Raw Mix

Where to Fire …

Cement Kiln: It is steel tube 100 to 500 feet long and 8 to 15 feet diameter. It is inclined to the horizontal by 2.5° from horizontal

• It is rotated clockwise with a rate of 1 turn per 2 minutes.

• As it rotates, the kiln feed moves toward the lower end.

Fuels that have been used for primary firing include coal, natural gas and others.

Heat Distribution in Kiln –  Oxygen Distribution in Kiln

Heat even distribution affects the quality of produced clinker

Cement kiln is lined by different types of Refractory Bricks

How to Fire ..

Raw Mix enters the kiln through the Preheater Cyclons.

Raw Mix is affected by hot gases recovered from the kiln

• The cyclons clean-up the dust-laden (dust loaded gases).
• Homogenization of Raw Mix
• Efficient cooling of Exhaust Gases (Environmentalimpact) due to Heat Exchange with the Raw Mix(Economical impact) so efficiently heated.

Initial Feed of the Raw Mix

The Kiln feed is passing different reactions

Clinker Formation

The Clinker is cooled in the Cooler. Once cooled, it is ready for grinding

The Clinker heat is recirculated back to the Kiln or the Preheater

The Clinker: C3S, C2S, C3A and C4AF

The  Clinker  is ground in a ball mill filled with steel balls

Different additives are added such as gypsum to control the set. Now we have the Portland Cement

Portland Cement

The clinker and/or the cement can be stored in Silos

Most cement is shipped by trucks, or may be bagged

Cement Carrier

It can be shipped to ready-mixed concrete producers. Where, it can be combined with water and suitable prop. of aggregates (sand and gravels).

The concrete is delivered to costumer in trucks with revolving drums

LAB CONTROL 

will continue the next four chapters very soon