How to build a small vertical shaft lime kiln
Practical Action
Kiln and ramp material quantities
Item
Interface paper
Brickforce
Bricks
Vermiculite
Refractory bricks
Fire clay
Cement
Chimney and chute
Chimney holding down bolts
Inspection pipes
Reinforcement
Reinforcing mesh
Discharge door and frame
Discharge opening frame
Metal bands and tension rods
Handrails
Hydrated lime
Stone
River sand
Pit sand
Ramp, steelwork
Ramp, boards
Quantity / Size
1⁄3 roll (14.5m2)
105m x 230mm
4000 units
24 x 25kg
900 units
6 x 50kg
25 x 50kg
1 unit
8 No. 10mm mild steel bolts, 150mm long
5 x 50mm dia. x 500mm
8 x 5.5m; X12 x 26m; X10 x 23m
2m2
480mm x 564mm x 6mm; 30mm x 20mm x
2mm x 2160mm square section
40mm x 40mm x 3.5mm angle x 1480mm;
100mm x 100mm x 8mm x 805mm
50mm x 5mm x 18.2m; 12mm dia. x 18m
25mm x 25mm x 3mm x 11.5m tube; 50mm
x 50mm x 5mm x 10m angle iron
15 x 50kg
3m3
3m3
3m3
25mm x 25mm x 3mm x 20m tube; 50mm x
50mm x 5mm x 18m angle iron
11 x 50mm x 152mm x 6300mm
Infrastructure and accessories
A ramp or hoist is needed to get limestone and fuel to the top of the kiln. If a hoist is
used, then a cat ladder or stairs will be needed for worker access to the platform. The
platform should be fitted with a safety handrail.
The Chegutu chimney is fitted with a swivel chute for loading the limestone. A simpler
solution may be to use a loose chute.
Access to the inspection/poking holes can be provided by a portable ladder or a fixed cat
ladder with protection hoops.
Costing and quantities
In 1996 the total cost of building the Chegutu Kiln was Z$47,500 (approximately £2,700,
excluding design and supervision costs). This cost was made up of Z$36,500 for materials
and Z$7,000 for labour plus Z$4,000 for infrastructure and accessories. Specified
improvements are unlikely to increase costs by more than 10%.
The main costs were refractory bricks at 32% of the materials cost and the chimney at
25%. These are likely to remain the major costs for a similar kiln in any location.
Programme
For planning purposes, the following programme can be used:
Day 1:
Site clearance and excavation for foundation. Start fabrication of chimney
plus any infrastructure and accessories.
Day 2:
Cast foundation slab.
Day 3–10:
Cure foundation slab.
6