Experimental Study on Physical and Mechanical Properties of Phosphorous Tailings

It is to study the physical and mechanical properties of phosphate rock and provide data support for the stability control of phosphate tailings dam. A series of laboratory test and a BI-90Plus laser particle size analyzer were used to test the original tailings. 13 basic physical properties and 4 indexes of mechanical properties of tailings are obtained. The results showed that most tailings of the dam are composed of a silty clay with high plasticity, remarkable expansion and contraction behavior. Particle size approximately follows a Gaussian distribution. The results of direct shear tests showed that as the clay content of the tailings increase, the internal friction angle tends to decrease, whereas the cohesion seems to increase gradually. And the difference reaches several times to dozens times. Therefore, the scientific and reasonable tailings discharge in accordance with the grain gradation and physical and mechanical properties of tailings, have an important influence on the stability of the dam. This may be related to the content of clay particles. The calculation results not only provide real data for the tailings dam design and stability, but also provides more accurate data support for engineering mechanical properties, the research of phosphate tailings sorting and storage process optimization.