Multi-Stage Flotation for the Removal of Ash from Fine Graphite Using Mechanical and Centrifugal Forces

Abstract

Graphite ore collected from Hunan province, south China was characterized by chemical analysis, X-ray diffraction, and optical microscopy. Rougher and multi-stage flotation tests using a mechanical flotation cell and a flotation column containing an additional centrifugal force field were carried out to promote its grade and economic value. In rougher flotation, both the mechanical flotation cell and flotation column reduced the ash content of the graphite ore from 15.43% to 10.8%, while the yield of the flotation column (91.41%) was much higher than that of the mechanical flotation cell (50%). In the presence of hydrophobic graphite, the seriously entrained gangue restricted further improvement in the quality and economic value of the graphite ore. Therefore, multi-stage flotation circuits were employed to diminish this entrainment. Multi-stage flotation circuits using the two flotation devices further decreased the ash content of the graphite ore to~8%, while the yield when using the flotation column was much higher than that obtained from the mechanical flotation cell employed. On the other hand, the ash removal efficiency of the flotation column was 3.82-fold higher than that observed for the mechanical flotation cell. The Cleaner 3 flotation circuit using the flotation column decreased the ash content in graphite from 15.43% to 7.97% with a yield of 77.53%.

Characterization and Removal Potential of Fluorine in Lignite from a Mine in Shaanxi Province, China: A Case Study

“…The release analysis test was performed to determine the floatability of the coking coal fines according to Chinese Standard GB/T 36167-2018 (Methods for coal preparation laboratory timed-release flotation analysis). Flotation release tests were performed based on published literature [40][41][42]. The flotation time was constant at 3 min for different flotation stages of release flotation.…”

Combined Column and Mechanical Flotation Cell Process for the Beneficiation of Sanshandao Gold Ore

“…Many studies have claimed that the flotation column technique yields higher recovery with better grades for fine particles during the cleaner stage. 10 − 13 Meanwhile, several works performed by the authors 14 , 15 have shown that mechanical flotation cells have advantages in recovering coarse particles at rougher or scavenger stages. In recent years, combined column and cell flotation processes have been applied to many mineral beneficiation processes and have improved the overall performance.…”

A Downhole Hydrocyclone for the Recovery of Natural Gas Hydrates and Desanding: The CFD Simulation of the Flow Field and Separation Performance

“…In downhole hydrocyclone, as a key component of the downhole in situ separation system, the performance and flow field characteristics play a decisive role. Hydrocyclones are widely used in various engineering processes because of their simple design, flexible operation, large capacity, and low maintenance costs [12,13]. Flow field characteristics are highly complex multiphase structures in a hydrocyclone.…”

“…However, the application of a hydrocyclone to recycle NGH and desand during NGH exploitation is a novel idea, and its performance needs to balance the recovery rate of the NGH outlet and the removal rate of the sand outlet. Nevertheless, the flow field and Hydrocyclones are widely used in various engineering processes because of their simple design, flexible operation, large capacity, and low maintenance costs [12,13]. Flow field characteristics are highly complex multiphase structures in a hydrocyclone.…”

“…The flow rates can be obtained by multiplying the inlet velocity by the inlet area. A velocity inlet (8,12, and 16 m/s) and pressure outlets (Relative pressure 0) were used. No slip boundary condition was adopted for the wall boundary.…”