Narrow Results

Tailings from an indigenous mining community were analyzed by PIXE to study the residual amount of gold and to check the relative increase in mercury content after the mineral dressing. The result showed that gold is sometimes left in the tailings at ore-grade concentration up to 30 ppm, and that relative mercury content is not increasing drastically. Since the tailings are trade target in the local community, it would be necessary for stakeholders to have a common and fair facility where they can assay gold content of the tailing at regular interval.

Water and tailings from lead-mining area in Kanchanaburi, Thailand were analyzed by PIXE to study how serious the alleged pollution was. Eleven water samples were collected in the field and were sealed in the tube after the pH < 2 was attained by ultrapure nitric acid. All of the samples were transported to Nishina Memorial Cyclotron Center of Japan Radioisotope Association and analyzed by its vacuum PIXE. The result showed that the water contains up to 25 ppb Pb with an average value 12 ppb. The value is lower than the environmental norm in Thailand (0.05 mg/L) but higher than that of WHO (10 μg/L = 0.01 mg/L). Tailings contain high amount of lead. Since resumption of mining is being considered to deliver the economic expectation of local people, it should be invested in treatment or containment within storage facilities. Also discharge of treated process water should be regularly monitored by competent agencies.