Materials Needed for starting one brick factory.
Clay
Clay soil must be able to show several properties to be used for brickmaking.
Plastic when mixed with water
Have enough tensile strength to keep its shape
Clay particles must fuse together
Clay soils are compounds of silica and alumina. Calcareous clays have calcium carbonate and will burn to
a yellow or cream color. Non-calcareous typically contain feldspar and iron oxides, and will burn to a
brown, pink or red, depending on the amount of iron oxide.
The silica in the clay, when fired at 900-1200 degrees C, will turn to a glassy phase. This process,
called vitrification, will turn the clay to a crystalline structure. Therefore, temperature is important.
If under-fired, the bonding between the clay particles will be poor and the brick will be weak. If the
temperature is too high, the bricks will melt or slump.
Vitrification does not have to be complete, and does not actually occur in many of the small traditional
brickmaking plants around the world. However, the vitrification does occur enough to give sufficient
strength to the brick.
It takes approximately 3 m3 of clay soil to make 1000 bricks.
Water
There will need to be enough water for the clay, a source of water must be available during brick
production. Therefore, a source that is not present the entire year (for example, only during rainy
season) will limit the brick production.
Also, the brickmaking production should not be in competition for water with other users. If a water
source is a communal source, the water needed for brick production can take away from the other uses
of water, such as drinking and cooking, washing, livestock watering and other domestic uses. It takes
approximately 600L of water to produce 1000 bricks. A convenient method of storage is to use 3-200L
drums.
Sand
Sand can be used to make minor adjustments to the quality of soil-it can be added to soil when drying
to prevent the soil from becoming too brittle. Sand is also be used as a stabilizer in a mixture. An
important use of sand is in the brickmaking process, where it is used to keep the bricks from sticking
to the molds.
If no sand is available in a location where brickmaking is going to start up, sawdust, ash and fine dry
soil can also be used to keep the clay from sticking to the mold.
Fuel
Firewood and coal are the most common fuel sources used for firing bricks.
Coal waste from a power plant is the easiest coal source to use, if available in the area. For 1000 bricks,
it takes 1 and 1/8 sacks of coal and 1/2 sack of cinder.
Approximately 3 m3 of firewood is needed to fire 1000 bricks. Since so much firewood is needed, there is a
risk of denuding a natural forest and depleting a family’s supply. On average, only 2 to 8 m3 of firewood
per hectare per year is available in a natural forest. In a well managed woodlot, 25 to 60 m3 of firewood
can be produced annually in the same area. There are also other advantages to woodlots, such as another
food source, use as a wind break and erosion protection.