Direct revegetation techniques for coal tailings dam no. 3 at Saraji coal mine Central Queensland

 Coal tailings are produced as a waste product from washing the fine < 2 mm fraction of mined coal to add value to the saleable product. After washing, slurried tailings are pumped to holding dams for disposal and desiccation. Once full the core of these dams dry slowly limiting vehicular access for reprocessing or rehabilitation works. In areas where evaporation exceeds rainfall, a dry surface crust, susceptible to generating wind blown dust, develops during this desiccation phase. A revegetation strategy involving establishing vegetation directly on coal tailings was therefore developed, to reduce wind blown dust hazards whilst maintaining the potential for later coal extraction. The field studies for the project were  depth. In the wetland plant available water was adequate for plant growth but the material was poorly aerated where moisture content was high. ... This thesis demonstrated the establishment of salt tolerant vegetation was possible on tailings dam number three at Saraji Mine and, therefore, revegetation with the view of minimising dust and maintaining access was feasible. Treatments that facilitated vegetation establishment in the field were those that decreased salinity and increased plant available water (mulching and irrigation). Nitrogen and phosphorus fertiliser additions were shown to be necessary in the glasshouse. Given that low plant available water and high salinity were the major limitations plant growth, provided follow up fertiliser is applied, trees and deep rooted vegetation should continue to survive and grow once their roots are have developed sufficiently to access the higher moisture/lower salinity sub -surface tailings. With increased vegetative biomass, the volume of leaf litter produced and dropped onto the tailing surface would increase and "self mulching" could occur. Further monitoring to investigate the longer term "self mulching" potential, C. glauca water usage rates and changes in species composition are recommended.