2. KHD Humboldt Wedag GmbH
Limestone / Clay
+ Corrective Components
Gas Conditioning
Waste Gas Cleaning
CaCO3
SiO2
Al2O3
Fe2O3
Raw Meal-Silo
• Homogenisation
• Stock Piling
Wednesday, January 28, 2009 2
Fuel Preparation
Raw Material Grinding
Stack
Cooler Waste Air
Cement
Thermal Process
•Pre-Heating
•Calcination
•Clinker Burning
•Clinker Cooling
Finish Mill
Pre-Blend Pile
3. KHD Humboldt Wedag GmbH
1 Overview – From Quarrying to Pre-Blending
1.1 Raw Material – Exploitation at quarry
1.2 Crushing plant
1.3 Pre-Blending
Wednesday, January 28, 2009 3
4. KHD Humboldt Wedag GmbH
Limestone / Clay
+ Corrective Components
Gas Conditioning
Waste Gas Cleaning
CaCO3
SiO2
Al2O3
Fe2O3
Raw Meal-Silo
• Homogenisation
• Stock Piling
Wednesday, January 28, 2009 4
Fuel Preparation
Raw Material Grinding
Stack
Cooler Waste Air
Cement
Thermal Process
•Pre-Heating
•Calcination
•Clinker Burning
•Clinker Cooling
Finish Mill
Pre-Blend Pile
5. KHD Humboldt Wedag GmbH
1. 1 Exploitation at Quarry by Ripping or Drilling and Blasting
Wednesday, January 28, 2009 5
6. KHD Humboldt Wedag GmbH
Typical Components for the Clinker Production
Lime Stone (CaO) ~ 85 %
Shale or Clay (SiO2, Al2O3, Fe2O3) ~ 15%
Additives, Corrective Components (SiO2, Al2O3, Fe2O3) 1 %
Example for raw mix composition (on ignited basis)
CaO 65 – 68 %
Wednesday, January 28, 2009 6
CaO 65 – 68 %
SiO2 20 – 23 %
Al2O3 4 – 6 %
Fe2O3 2 – 4 %
MgO 1 – 5 %
Mn2O 0,1 – 0,5 %
TiO2 0,3 – 0,5 %
SO3 0,1 – 1 %
K2O 0,1 – 1 %
Na2O 0,1 – 0,5 %
12. KHD Humboldt Wedag GmbH
1. 2 Crushing Plant
Typical feed size of rocks after mining should be in a range of less than 1200 mm.
Commonly there are primary, secondary and, occasionally, tertiary crushers in series.
Wednesday, January 28, 2009 12
Target for product size after crushing depends on raw mill system, e. g.:
For grinding in ball mill: app. 5 % Residue on 15 – 30 mm
For grinding in vertical mill: app. 5 % Residue on 50 – 100 mm
13. KHD Humboldt Wedag GmbH
Crushing Principles:
Compression or Impact Forces
Wednesday, January 28, 2009 13
15. KHD Humboldt Wedag GmbH
1. 3 Pre-Blending
Target is:
to pre-homogenize the raw material after crushing.
to have an stock pile for raw meal grinding without full shift quarry operation.
The blending bed technology is for the main components together or for each component
Wednesday, January 28, 2009 15
The blending bed technology is for the main components together or for each component
separately.
The main components are limestone and the aluminosilcate component (clay or shale).
The blending effect, H, is generally determined as the ratio between the standard
deviation Sin of one significant chemical parameter of the input to a given stockpile and the
standard deviation of the same parameter Sout of the output from the same stockpile, as
follows:
Blending effect, H = Sin/ Sout
16. KHD Humboldt Wedag GmbH
Chevron Method
For longitudinal (Chevron Method) or
circular (Chevcon Method) stockpiles.
In building up a traditional longitudinal
stockpile by the Chevron method, the
stacker moves to and for over the
central line. It is a discontinuous
Wednesday, January 28, 2009 16
central line. It is a discontinuous
technique by which stacking takes
place in one half portion of the
stockpile, while the other half portion
is reclaimed (at pile end).
In the circular stockpile build-up by
the Chevron method, there is
a continuous round base with
stacking at one end and reclaiming at
another.
17. KHD Humboldt Wedag GmbH
Windrow Method
In the Windrow method, material is
deposited from a number of positions
across the full width of the pile. This
method, essentially followed to build
up longitudinal stockpiles, prevents
segregation of coarse and fine raw
Wednesday, January 28, 2009 17
material and is preferred in cases
where the reclaimer operates in one
part of the pile cross-section at a time
or where segregation may create
situations of total unacceptability.
18. KHD Humboldt Wedag GmbH
Example of a Chevron Blending Bed, Stacker and Reclaimer
Wednesday, January 28, 2009 18
