Installation of Refractory Materials in Rotary Kilns ”Essential principles"

Installation of refractory
materials in rotary kilns
”Essential principles”

3©Refratechnik Cement GmbH
Contents
1. Preparation – before the kiln is stopped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Preparation – after the kiln has stopped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Preparation – bricklayer’s personal protective equipment (PPE) . . . . . . . . . . . . . . . . . . . . . 6
4. Essential lining tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Kiln shell preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Commencement of lining – reference lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Commencement of lining – placing the first bricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8. During the lining – correct mixing ratio of bricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9. Refratechnik‘s brick marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10. Dilatation of basic and alumina bricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11. Installation on deformed kiln shell and welding seams . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
12. Keying of brick rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
13. Installation, using the REFRA-Rig II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
14. Connecting a new lining to an old one . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
15. The editors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Before the kiln stop, make sure to have all necessary information available:
• safety regulations
• kiln stop schedule
• refractory lining history
• material lists (on stock and pending orders)
• availability and condition of own and rented tools
• contracts with subcontractors
• preparatory meetings with production and maintenance staff members
as well as subcontractors
• In the case of any doubt, suppliers should be contacted.
1. Preparation – before the kiln is stopped

2. Preparation – after the kiln has stopped
• Before starting any job, ensure that a safety briefing has been given
to all people involved in the kiln stop.
• Make sure that there are no meal/clinker/coating deposits left.
In the case of any blockings and/or coatings, have them removed before entering
the clinker production line.
• Before starting the demolition job, measure the remaining brick thickness either
using an electronic device or manually by drilling holes into the refractory lining.
This drilling should always be done in a joint running between minimum 3 bricks.
• Based on bricking history, expected duration of next campaign and determined
remaining brick thickness, it is decided which areas need to be replaced.
• For areas to be relined, calculate the required amounts of material and compare
them with the existing stock. Thus you will ensure to have available sufficient
amounts of material on site.
• Fully illuminate the areas to be replaced, before starting the relining job.

Make sure that all personnel entering the kiln will wear their PPE:
Depending on the work actually carried out, some additional protective equipment
may be necessary:
3. Preparation – bricklayer’s personal protective equipment (PPE)

masonry trowel
spirit level
brick cutting saw
mortar mixer
rubber mallet
forced action mixer
(if refractory concrete
is installed)
steel hammer
manual shim driver
pneumatic shim driver
4. Essential lining tools

5. Kiln shell preparation
In order to achieve an adequate lining lifetime, the kiln shell must be dry and free from
impurities, such as scale, grease and moisture and must not show any kiln shell corrosion.
Proper kiln shell condition Kiln shell corrosion

6. Commencement of lining – reference lines
Reference lines are essential to achieve a correct alignment of the brickwork.
• Draw reference lines onto the kiln shell parallel to the radial welding seams.
The distance between two lines should be max. 2 m. The lines can also be
plotted onto the kiln shell by means of a rotation laser. Strictly follow these
reference lines when installing the brick rings.
• For the correct alignment of a new lining, take an axially running welding seam
as a reference line. If suitable welding seams are missing, you can determine
the axial line with a spirit level and a plumb.

axial welding seams
on kiln shell
parallel
alignment
radial welding
seams on
kiln shell
axial joints
parallel alignment
radial joints
auxilary reference line,
e.g. chalk line
Reference lines for correct alignment of the brickwork

Marking up of reference lines:
Determination of the kiln axis with spirit level and masonry plumb

Place a timber batten or steel angle along this line,
and fix it to prevent the bricks from shifting.
7. Commencement of lining – placing the first bricks

Recommended lining pattern,
to avoid interlocking of individual brick rings

8. During the lining – correct mixing ratio of bricks
• A combination of two shapes with a ratio as close as possible
to 1 : 1 is to be preferred.
• In any case, try to follow the pre-calculated mixing ratio shown in the installation
drawing.
• Deviations in a clench lining can be corrected with suitable mortar.
• Therefore always have some mortar in stock, even if a clench lining is planned.

Refratechnik‘s installation drawing

correct kiln center
small B-dimension
correct false
large A-dimension
horizontal joints
False installation (overarching)

correct kiln center
small B-dimension
correct false
large A-dimension
horizontal joints
False installation (underarching)

AG85
B120
AG85
B220
AG85
B320
AG85
B420
AG85
B520
AG85
B620
AG85
B720
AG85
B820
AG85
BP20
9. Refratechnik‘s brick marking
B 216 B 316 B 416 B 516 B 616 B 716 B 816
B 218 B 318 B 418 B 518 B 618 B 718 B 818
B 220 B 320 B 420 B 520 B 620 B 720 B 820
B 222 B 322 B 422 B 522 B 622 B 722 B 822
B 225 B 325 B 425 B 525 B 625 B 725 B 825
B 230 B 330 B 430 B 530 B 630 B 730 B 830
AG85
B420
AG85
B520
AG85
B620
AG85
B720
AG85
B820
AG85
BP20
brick type
brick shape
nominal diameter
brick height
Basic bricks (VDZ shapes)
Keybricks

KX50
120
KX50
220
KX50
320
KX50
420
KX50
520
KX50
620
KX50
720
KX50
820
KX50
P 20
216 316 416 516 616 716 816
218 318 418 518 618 718 818
220 320 420 520 620 720 820
222 322 422 522 622 722 822
225 325 425 525 625 725 825
230 330 430 530 630 730 830
KX50
420
KX50
520
KX50
620
KX50
720
KX50
820
KX50
P 20
brick type
brick shape
nominal diameter
brick height
Alumina and high alumina bricks (ISO shapes)
Keybricks

10. Dilatation of basic and alumina bricks
no expansion joints
2 mm cardboard spacers in radial joints
inlet
A B
C
D
E
F
index zone brick grades installation
method
expansion of
axial joints
expansion of
radial joints
A outlet zone high alumina bricks

magnesia spinel bricks
clench or
with mortar
no expansion no expansion
2 mm cardboard
spacers (1% of
brick length)
B lower
transition
zone
magnesia zirconium bricks
magnesia chromite bricks
clench or
with mortar
no expansion 2 mm cardboard
spacers (1% of
brick length)

index zone brick grades installation
method
expansion of
axial joints
expansion of
radial joints
C burning
zone /
sintering
zone
magnesia pleonaste bricks
magnesia hercynite bricks
magnesia magnesium silicate b.
clench or
with mortar
spacers
(1% of
brick length)
D upper
transition
zone
magnesia pleonaste bricks
magnesia hercynite bricks
magnesia chromite spinel bricks
clench or
with mortar
spacers
(1% of
brick length)
E safety zone alumina or high alumina bricks
special high alumina fireclay b.
silicon carbide containing bricks
clench or
with mortar
F preheating
zone
refractory light weight
materials or alkali resistant
special fireclay bricks
clench or
with mortar

• Refractory materials show different thermal expansion behaviours. A certain thermal
expansion is of course a desired property, because it helps to tighten the lining after
start-up. However, the increased thermal expansion of magnesia bricks in the sintering
and transition zones is too high and has to be compensated for by cardboard spacers.
These cardboard spacers are generally pre-attached to the bricks already.
Please do not remove them!
• High alumina, alumina rich and lightweight bricks in the rotary kiln however do not need
any additional expansion joints, since the expansion of these materials is not as high.

There are often faced problems when installing the bricks over welding seams.
In order to achieve a good lining quality, please observe the following hints:
• In the case of welding seams or deformations of less than 8 mm in height, fill up the gap
between kiln shell and bricks with mortar so that the rings on the welding seams can be
installed parallel to the other brick rings.
• For welding seams and deformation higher than 8 mm, the bricks over the welding seams
need to be cut out. The remaining gap is then filled up with mortar, too. For both methods,
make sure that at least one corner of the brick is in contact with the kiln shell.
11. Installation on deformed kiln shell and welding seams

max.8mm
to be filled with mortarkiln shell
max.8mm
to be filled with mortar
kiln shell
Bricking over welding seams max. 8 mm in height

8mm
bricks to be cut on installation
kiln shell
kiln shell
Bricking over welding seams higher than 8 mm

Bricking over kiln shell deformations is more complicated, and therefore the bricks need to
be laid most accurately. So, please consider the following points:
• Make sure that at least one part of the a-side (cold face) of the bricks fits tightly against
the kiln shell.
• The axial joints have to point exactly in the direction of the center of the kiln
and parallel to the kiln axis.
• All bricks installed over a distorted kiln shell should be mortared. The maximum joint
thickness between two bricks must not exceed 1-1.5 mm.
• For smoothing out any irregularities, mortar with a maximum thickness of 8 mm is filled
between the brick‘s cold face and the kiln shell. Refrain from using any ramming mix or
refractory concrete, since they are not designed for such small layers.
• If a deformed area in the section is to be lined, turn the kiln in such a way that the
deformation is in a position between 7 and 9 o’clock, or between 3 and 5 o’clock, before
starting the bricking job. The distorted kiln shell section should never be in the key area of
the rings.

In the case of bricking over a deformed kiln section in the lower half of the brickwork,
apply the so-called “window” method. This implies that you install the brickwork as close
as possible to the deformation. Then leave an opening, i.e. a rectangular “window” frame,
in the area of deformation. Only after having completely installed the adjacent 3 to 4
rings, close the remaining window. This method helps to get parallel joints, also in the
deformed section.
• Even if you brick over a deformation in the kiln shell, do not change the mixing ratio.

max. 8 mm
Installation of refractory bricks over a distorted kiln shell
(correction with mortar, radial view)

max. 8 mm
Recommended installation of refractory bricks over a distorted kiln shell
(correction with mortar, radial view)

mortar joint max. 1-1.5 mmmax. 8 mm
Recommended installation of refractory bricks over a distorted kiln shell (axial view)

mortar joint max. 1-1.5 mmto be filled with mortar: max. 8 mm
Recommended installation of refractory bricks over a distorted kiln shell (axial view)

12. Keying of brick rings
A tight fit of the refractory lining in the rotary kiln is achieved and premature wear is
avoided by observing the following points:
• Do only use standard brick shapes to close the rings. Avoid any cutting of bricks
in axial direction to close the rings.
• Ensure that the axial joints of the bricks point exactly parallel to the kiln axis,
also in the key section.
• The thickness of the metal shims required for keying of the individual bricks
must not exceed 2 mm.
• Never use more than one metal shim per joint.
• If several metal shims need to be driven-in for keying of bricks, distribute them
over the entire keying area.
• Use a mix of key bricks and standard shaped bricks to get the best fit in the closing
section. Avoid to place two small key bricks side by side.

• Never insert keying shims next to a small key brick.
• For closing the rings always use a hydraulic jack. This jack has to be equipped with rubber
plates at both ends and is to be aligned according to the brick ring's center line.
• To avoid damaged key bricks, the pressure applied must not exceed 50% of the bricks
“cold crushing strength” (CCS).
Example
TOPMAG® AF cold crushing strength (CCS) = 70 N/mm²
Pressure to be applied 350 bar = 5000 psi = 35 MPa

keying shims to close the rings
1st
shape 2nd
shape key bricks
Correctly placed key bricks and keying shims

13. Installation, using the REFRA-Rig II
• REFRA-Rig II consists of a movable arch, equipped with pneumatic pistons, to
press the refractory bricks to the kiln shell, mounted on a mobile aluminum platform.
• REFRA-Rig II is available for kiln diameters from 3.50 to 6.50 m.
Refratechnik’s REFRA-Rig II, type 18/34, is designed for kiln diameters from
1.80 to 3.40 m or for tertiary air ducts with those diameters.*
• Since the equipment is movable, the entire structure can be easily moved within the kiln.
There is no need for reassembling the platform during the installation job.
• Since the kiln is not rotated, access paths, electrical wiring, illumination and material
transport systems can remain in place throughout the installation job.
• Simultaneously working on both, lower and upper half of the kiln shell, is possible.
• Very reliable method.
• High bricking progress.
* Working range:
REFRA-Rig II: 2.900-6.100 mm (inside diam. of lining)
REFRA-Rig 18/34: 1.400-2.800 mm (inside diam. of lining)

For more information, kindly refer to our brochure “Product Information”.

Installation, using the REFRA-Rig II

14. Connecting a new lining to an old one
During a kiln stop, areas with a good remaining brick thickness are normally left in the kiln.
So, the new lining has to be connected to the old one. This can either be on one or on both
sides of the new lining.
• Even with an optimally aligned brickwork, both linings have to be connected by cutting
bricks. The distance within one ring of the new lining can also differ. If the gap ranges
between 200 and 300 mm, it is necessary to cut either two standard shaped bricks or one
L shaped brick, which are also available with Refratechnik in VDZ and ISO shapes.
• In the case of cutting two standard shaped bricks, the minimum length is half a brick
(100 mm). We recommend to use L shaped bricks, since the brickwork has a higher
stability, and cutting one brick instead of two bricks is more cost-effective.

new lining old, still existing liningL shaped bricks
Recommended pattern to connect new brickwork to an old lining

15. The editors
This guide provides a brief overview and does not claim to be complete,
especially with regard to work safety and prevention of accidents.
For more detailed information about refractory linings in the rotary kiln
as well as in static areas of a clinker production line, kindly also refer
to Refratechnik‘s “Installation manual for refractory materials in rotary kilns
and corresponding aggregates”, latest issue.
For any further questions you may have, please do not hesitate
to contact your local Refratechnik representative.

Refratechnik Cement GmbH
Rudolf-Winkel-Strasse 1
37079 Göttingen
Germany
Phone +49 551 6941 0
Fax +49 551 6941 104
cement@refra.com
www.refra.com
Ce1-194-12/2017Ce1-194-12/2017

Installation of Refractory Materials in Rotary Kilns ”Essential principles"

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