Enhancing classification and recovery of barite from waste drilling fluid by inlet particle arranging of hydrocyclone

Improper disposal of waste drilling fluid will cause severe pollution of the ecological environment and massive loss of resources such as barite. Based on the principle of arranging particle to enhance the hydrocyclone classification, a triple hydrocyclone pre-sequencing grading system for treating waste drilling fluid was designed in this paper. The influence of the swirl particle arranger and its cone angle on the classification and recovery characteristics of barite particles in waste drilling fluid was studied. The results showed that under experimental conditions, compared with the triple hydrocyclone grading system without the particle arranger, the recovery rate of barite increases by 5.7 % to 75.0 % after setting a cylindrical arranger in front of hydrocyclone. As the arranger's cone angle increases, the device's classification performance increases first and then decreases. The classification performance was best when the arranger cone angle was 6°. At this time, the solid content of drilling cuttings in the recycled purified fluid was only 27.1 g/L. This was 47.9 % lower than the inlet. And the recovery rate of barite reached 78.9 %. This technology can realize the deep removal of drilling cuttings, the efficient recovery of barite and the recycling of betonies. [Display omitted] •The strengthening of classification by particle arranging was studied.•The best structure of swirl particle arranger cone angle was founded.•The outlet of the solid content of drilling cuttings was only 27.1 g/L.•The recovery rate of barite can reach more than 70 %.