2015 Volume 83 Issue 2 Pages II_1-II_8
Import of rice is increasing and production increase of rice is required from a viewpoint of food security in sub-Sahara Africa. Although an irrigation paddy field is effective in production increase of rice, many canals are unlined, a sudden heavy rain etc. erode them, and a water supply function deteriorates. For this reason, the structure of suppressing erosion is required. But firm reinforcement by cement etc. cannot be performed, since farmers do not have sufficient capital. Then, how to generate a soil hardening material (calcium oxide) easily from the shell (calcium carbonate) was examined as a low cost canal reinforcement measure which farmers can implement. As a result, 800℃ required for calcium oxide generation was obtained using kiln with covering the upper part which can be easily constructed on site. Moreover, it turned out that a calcium oxide can be efficiently obtained by performing two-step burning. Furthermore, it found that the production cost of a kiln is equivalent to five bags (50 kg per bag) of cement.