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Zambian Double Wall Clay Stove by Dr Lubaba et al.

Boiling Point
Front cover of Boiling Point issue 31
Issue 31 (1993) Clays for Stoves
ArticleZambian Double Wall Clay Stove
AuthorDr. Lubaba, Dr Banda, Mr Minamikawa
The ceramics research laboratory in the Building and Industrial Minerals Research Unit of the National Council for Scientific Research (NCSR) has characterized various Zambian clays to determine their suitability for the manufacture of a portable, charcoal burning stove made out of fired clay without a metal cladding as used for the Kenyan Ceramic Jiko.

Work started in 1987 under the joint sponsorship of the Government of the Republic of Zambia (GRZ) and Japan International Co-operation Agency (JICA), to replace the current, widely used mbaula (brazier). The inefficient utilisation of charcoal leads to its high demand, which leads to massive destruction of forests resulting in environmental costs in terms of loss of soil fertility, soil erosion, and disturbance of natural drainage systems which could result in reduced water retention.

The project aims to make a clay stove which uses charcoal efficiently and which:
  1. does not crack from thermal stresses during use for a period of at least one year.
  2. holds enough fuel to complete any cooking cycle started on the stove.
  3. is well insulated so that it can be moved about with bare hands while it is in use, ie. the outside part of the stove shall not be too hot to handle with bare hands.

[top] [end]Research Results

The research has characterized various clays and non-plastic ceramic materials that are suitable for the manufacture of the stove.

The stove based on a Japanese design, as shown in Figures 1 and 2, has been made in the laboratory from suitable clays. This type of stove has two separate parts, an inner and outer jacket, to increase the insulation properties of the stove, to keep the outside of the stove cool and to facilitate construction. Charcoal is placed in the top of the stove as with the KCJ.

Cracking of the stove during use has been prevented by combining clay body formulation considerations, firing temperature of the final product and design considerations of the fuel holding chamber.

Because of the success achieved at the laboratory level, the Zambian National Council for Scientific Research has now built a pilot plant with a production capacity of about 1000 stoves per month to produce the clay stoves on a semi-commercial basis. However, the plant is currently producing only 400 stoves per month because of limited kiln capacity.
Figure 2: The Zambian NCSR charcoal stove adapted from a Japanese claystove
Figure 2: The Zambian NCSR charcoal stove adapted from a Japanese claystove


The stoves are sold to urban households for the purposes of establishing performance standards and also for popularising the claystove in the urban centres. Users must be encouraged to utilise charcoal more efficiently to save the forests as charcoal is made from felling live trees.

Another NCSR team is working on the development and production of coal briquettes. The briquettes are targeted towards replacing charcoal as domestic fuel in the near future.

[top] [end]Contents: Boiling Point 31: Clays for Stoves

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Effects of the Clay-Non Clay Ratio on Stove Behaviour - Clay-Non Clay Test Procedure - Clay Testing - 5 Country Reports - Clay Preparation Techniques - The Sudanese Muddy Stove - Cement Stoves from India - The Chencottai Chulah - Zambian Double Wall Clay Stove - Kenya Downdraught Kiln for Stove Liners - The KCJ - from Artisan to Factory - Working with Village Women in NWFP Pakistan - Smoked Maasai - Kachel Ovens - Metal Stoves for Developing Countries - Chimney Design

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Page created: 29 August 2007; Last edited: 27 November 2008; Version: 1
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Pagename: ZambianDoubleWallClayStove @HEDON: WCHA