摘要:Production of rice husk in Central Java province is around 2,825,000 tonnes annually. It can be used as an alternative energy source to substitute coal in combustion during cement production. This study was conducted to determine the impact of rice husk as a substitute energy source in cement production. The observations of rice husk comprised calorimetric tests, physical and chemical tests, and percentage rice husk substitution for coal as firing energy. The chemical properties of the cement tested include the chemical content, MgO and SO3contents, loss on ignition, insoluble residue, and total alkali. The results show that the chemical content of cement which is produced using rice husk as a substitute for coal in the combustion process still meets the Indonesian National Standard.