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Researchers have reported in the past that inclined hydrocyclone operation can provide a lower water split to underflow and much coarser cut sizes. However, semi-inverted hydrocyclones (inclined higher than the horizontal position) have not been investigated in detail. This paper presents the results of a comprehensive study that was carried out at...
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Context 1
... adjust the energy balance to conditions more favourable to semi-inverted operation the original cone was replaced with a new shorter cone with a wider cone angle (15˚) as shown in Figure 3. The hydrocyclone test rig installation is schematically shown in Figure 4. The rig design allows the hydrocyclone to be tested at any angle of inclination. ...
Context 2
... suggests that the semiinverted hydrocyclone has a different flow regime than the conventional hydrocyclone. As the hydrocyclone cuts coarser and the WS is lower at semi-inverted positions, solids recovery to underflow decreases ( Figure 14, Figure 15 and Figure 16), especially for 42% solids at 135˚position135˚position. In that case, only 10 to 20% of feed reported to underflow, while in the other cases the value was greater than 30%. ...
Citations
... Semi-inverted cyclones are modified hydrocyclones installed at semi-inverted positions (higher than horizontal) as shown in Fig. 8. These cyclones can reduce the misclassification of fines to the underflow fraction and improve the recovery of water to the overflow fraction (Rasyid et al., 2019), and have classification efficiency similar to fine screening (Jokovic et al., 2020). Hybrid classification is a methodology employing both hydrocyclones (or screw classifiers) and fine screens to overcome deficiencies of these classifiers and minimise the misclassification of composite particles during size separation. ...
Demand for technologies delivering renewable energy and improving energy efficiencies are set to increase with the worldwide movement towards low carbon economies. Many of these technologies are reliant on “critical metals”: metals considered both important to society and vulnerable to supply disruption. Significant concentrations of critical metals have reported to mining and processing wastes over time; thus, an opportunity exists to meet critical metal demand through re-processing of these wastes. Mining and processing wastes have significantly different properties to run of mine ores. This means that while the overall mineral processing sequence for mining and processing wastes is the same as run of mine ore, the best technologies to achieve the liberation, separation, and concentration of critical metals is different. There are a range of innovative technologies that can be used to liberate and separate critical metals from mining and processing waste. Mineral liberation can be achieved using stirred milling, which breaks up particles and removes hydrophilic surface that can prevent particle flotation. Particle separation based on size can be achieved using semi-inverted cyclones and hybrid classification technologies. Separation of minerals from gangue can be achieved using flotation, with fluidised bed reactors and reactor-separator induced air reactors being suitable for coarse and fine particles, respectively. Gravity concentration using counter flow fluidised bed separators is also suitable for separating minerals from gangue. This review provides an overview of these technologies, as well as an introduction to the sequence of events when undertaking mineral processing, for an audience not specialised in this discipline. However, extraction of any metal value from tailings is contingent on detailed mineralogical characterisation. Three case studies are presented to demonstrate the analysis that is necessary as a crucial first step towards valorisation. Ultimately, implementation of these technologies to extract critical metals from mining and processing wastes will not only aid in meeting future critical metal demand but is essential for achieving a sustainable circular mining system with near-zero waste.
... Ye et al. [22] addressed the difficulties in the classification of ultrafine particles by traditional hydrocyclones, by studying a conical section cross-section and designing a multi-section composite cone. Jokovica et al. [23,24] proposed a semiinverted hydrocyclone and achieved encouraging results, significantly reducing the water split to coarse product and much coarser cut sizes. Tang et al. [25] used CFD technology to study the separation performance of hydrocyclone, under different inlet structure size and inlet velocity combinations. ...
Fine particles misclassification in the underflow (UF) of grinding-classification hydrocyclones might result in ore over-grinding, leading to both reduced ball mill throughput and metal recovery. In the current research, a W-shaped hydrocyclone is proposed, to efficiently decrease the misclassification of fine particles in UF. The effects of the following parameters (including cross-effects) on W-shaped hydrocyclone classification performance were studied experimentally—inlet pressure, apex diameter, and vortex finder insertion depth and diameter. A mathematical model on the basis of the response surface method was established for the prediction of W-shaped hydrocyclone separation performance. The significance of the effects of the factors on the fine particle content in UF decreased in the following order—vortex finder diameter > inlet pressure > vortex finder insertion depth > apex diameter. The significance of influences of different factors on quality effectively decreased in the following order—inlet pressure > vortex finder insertion depth > vortex finder diameter > apex diameter. The significance of factor effects on the quantity efficiency decreased in the following order—inlet pressure > vortex finder insertion depth > apex diameter > vortex finder diameter. All influence factors were considered to obtain the optimal parameter configuration—an apex diameter of 0.14 D, a vortex finder diameter of 0.31 D, an insertion depth of 1.87 D, and an inlet pressure of 0.18 MPa. The corresponding optimal result was a −25 μm particle content (C−25) in UF of 11.92%, a quality efficiency of 42.48%, and a quantity efficiency of 98.99%.
... This process happened on the radial direction. The turbulent intensity in the cone part is increasing for any the flow rate .Mohammad abdur rasyid et al [17] the effect of particle classification considered on semi inverted hydro-cyclone. They showed which deviation of angle effected on the separation of particle, on the other hand, amount of pressure loss related to cone angle and inclining the semi hydro-cyclone. ...
This research sought to examine a solid-liquid cylindrical cyclone separator, using the CFD simulation technique. By simulating the multi-phase flow using the Eulerian-Eulerian approach, the SIMPLE Pressure-velocity coupling solution algorithm was considered to simultaneously perform the pressure and fluid velocity analysis. In this way, we discussed the impact of three different turbulence models (RNG (k-ε), Realizable (k-ε), and RSM) on the results of the simulation, aiming to select the best model with acceptable accuracy among these three models (RSM) to evaluate the two-phase (solid-liquid) flow hydrodynamics. In other words, the present study aimed to optimize the parameters affecting the hydrocyclone separation. For this purpose, in order to conduct a statistical study of the CFD model on hydrocyclone performance parameters, a fluid model was developed based on response surface methodology to simulate target parameters based on design parameters with a mathematical polynomial. Finally, the neural network method was used to analyze and solve the optimization problem.
... Stirrers were used to avoid material settling inside the sump. More information about the test rig is provided by Rasyid et al. (2019). The ore sample was crushed to -6mm and divided into bags using the rotary splitter. ...
The devices most commonly used for classification in the mining industry are hydrocyclones. Hydrocyclones have been preferred over most other devices due to low operating cost and a small footprint and have not received as much attention as more expensive comminution units, and their technological progress has been incremental.
A classification study using semi-inverted hydrocyclones was conducted to determine if a hydrocyclone could be operated in a way that would produce similar results to a screen. The results from the study were encouraging with substantial reduction in water split to coarse product (Rf) and much coarser cut sizes. A hydrocyclone with lower water split to underflow (Rf) will improve classification of fines which would otherwise be sent back to the grinding circuit. The ability of hydrocyclones to cut coarser would potentially expand their application in the areas where the fine screens are currently in use. Therefore, the very low Rf and coarser cut are of paramount importance for a step change in future industrial operation. Other potential benefit compared with fine screens are reduction of the footprint required for the installation and in challenges in even slurry distribution.
The classification performance of a semi-inverted hydrocyclone will be presented in this paper.
