About 1 g of Oil Shale ashed at 750 ̊C was soaked in distilled water and agitated at 700 rpm. The values of pH and conductivity obtained at different conditions are shown in Figure 5. Generally, the pH of the leachate is as high as about 12 suggesting the alkalinity nature of Oil Shale ash. This is also evident from the mineralogy of the ash; CaO in water is converted to calcium hydroxide, which is slightly soluble in water (about 2 g/l at room temperature). From the environmental point of view, high pH when Oil Shale ash pH is regarded as advantageous in neutralizing acidic mine drainage (AMD) [14].