Preconcentration of a low-grade betafite ore by dense medium cyclone

Abstract

In order to find an economical and feasible short process for betafite preconcentrating and to provide a reference for the development of similar low-grade uranium deposits, preconcentration of the betafite ore was investigated based on mineralogical characterization study, float-sink tests, and dense medium cyclone (DMC) separation experiments. The float-sink test results revealed that the gravity separation of the betafite ore was feasible, and the expected particle size range was chosen to be 3~0.3 mm. The effect of important parameters of the DMC experiment such as particle size, grade of the feed, separation density, and inlet pressure on the separation performance of betafite ore was studied. Under the optimal experimental conditions, the expanded experiments were performed and the heavy minerals contained 4557 ppm U and 5200 ppm Nb2O5 with a recovery of 88.86% and 79.73%, respectively, were obtained. Besides, the enrichment ratio (E) values of U and Nb2O5 were 14.24 and 12.78 severally, and the tailings discarding ratio (R) value was 93.76%. The results demonstrate that the preconcentration of low-grade betafite by DMC can remove a large number of tailings and obtain a high-grade uranium concentrate.

Preconcentration of a Medium-Grade Celestine Ore by Dense Medium Cyclone Using a Factorial Design

“…On the other hand, for an even higher density of the medium (2.9 kg/L), the enrichment rate decreases notably (E = 1.061; 6.1%). These results do not follow the trend of increasing enriching with the density of the media observed by other authors [12]. Thus, in this case, the best results were obtained at a density 2.8 kg/L.…”

“…Separation by dense media is based on the difference in density of the mineral phases (Figure 3) and Archimedes' Principle (Equation ( 3)) [12].…”

“…Three parameters are used to characterise the separation performance: the enrichment ratio (E, Equation ( 4)), the tailings discarding ratio (R, Equation ( 5)), and the mineral processing recovery (ε, Equation ( 6)) [12]:…”

“…The variable density of 2.7-2.9 kg/L should be that inside the hydrocyclone. The density inside the hydrocyclone is between the densities at the vortex outlet and the apex [12].…”

“…The proposed method for celestine ore concentration is based on the difference in density between the mineral phase of interest (celestine) and the rest of the uneconomical mineral phases (gravimetric concentration). Density-based separation technologies have historically been used to process a variety of materials [12]. In particular, dense media cyclones (DMCs) have been widely used in mineral processing due to their advantages, including large processing capacity, high separation efficiency, and easy automatic control [13].…”