Long-term experience of practical applications and lab tests implies that the engineering characteristics of tailings is related to some factors such as mineral composition

damming layout

sedimentary characteristics of the ore pulp

and more closely to the particle size distribution of tailings. In order to analyze the upriver-type tailings variations of the particle composition and its influence on the tailings engineering properties after discharging

depositing

sorting

a series of tests is performed to determine the particle-size distribution

mechanical properties and permeability of tailings at different positions on depositional beach face

and the influence of the fine particles (particle diameter less than 0.075 mm) content on the engineering properties of tailing is analyzed. It is found that as the distance from the tailings beach crest increases

the composition of fine particle gradually increases

grain size distribution situation changes from normally to well-graded

then again normally-graded; void ratio initially decreases and then increases; the tailings cohesion grows gradually as the content of fine particles increases

whereas internal friction angle changes within a relatively small range; the permeability coefficient is significantly influenced by the fine particle content

and decreases rapidly with the increase of the content.