The purpose of this research was to study the temperature of burning surf clam shell for soil quality improvement. The experiment was divided two parts 1) the study of the optimum temperature for calcium oxide production by burning 800 900 1000 and 1100 °C 2) the study of using calcium oxide to improve soil qualities of acidic soil and saline soil. The parameters used in the analysis included elements of soil particles soil moisture pH conductivity total content nitrogen phosphorus and potassium. The results showed that the optimum temperature for the production of calcium oxide was 1100 °C since it provided the highest calcium oxide content of 90 % by weight. After applying calcium oxide into acidic soil the composition of soil particles was changed from sandy clay to sandy clay loam. In contrast the soil particle was not changed but the proportion was changed in saline soil. It was also found that calcium oxide reduced soil moisture and influenced the acidity of soil by increasing the pH from 3.39 to 6.92 in acidic soil and 6.49 to 9.11 in saline soil. In addition it was found that the electrical conductivity of the soil was related to salinity. In acidic soil the conductivity of before and after inputting calcium oxide were 0.87 and 1.24 dS/m respectively. In the case of saline soil the conductivity of before and after improvement were 14.37 and 18.80 dS/m respectively. Besides it was found that the total content of nitrogen phosphorus and potassium were reduced after the experiment.

The reduction of calcium carbonate (CaCO3) particle was prepared by wet grinding method with 40% dispersion. The particle sizes of CaCO3 were studied with various time of wet grinding. It was found that the particle sizes of CaCO3 rapidly decreased in 3 day of grinding after that it was slightly reduce. Therefore the CaCO3 at various time of wet grinding were mixed with concentrate latex (60% dry rubber content DRC). The result showed that the wet grinding for 2 days provided the superior machanical properties. In addition the compound with epoxidized natural rubber (ENR) as a coupling agent was investigated. It was found that the 5 phr of 30% mole percent of ENR results in significantly improved mechanical properties of the rubber vulcanizates.