NUMERICAL SIMULATION OF FINE PARTICLE SEPARATION IN A ROTATIONAL TUBE SEPARATOR

This paper presents a numerical analysis of gas-solid separation in a rotational tube separator. This separator which collects fine particles from gas in laminar flow is effective for fine particle separation. The separation efficiency and critical particle diameter of the separator were simulated using CFD package （FLUENT 6.0）. The simulation showed that separation efficiency can be significantly decreased due to the presence of turbulence. The simulation also showed that the Saffman lift force has little effect on the efficiency of this separator. The critical particle diameter of this tube separator was also calculated theoretically, Some experimental data were provided to validate the simulation results. Comparison between experimental results and simulation predictions on separation efficiency showed satisfactory agreement.

New Technologies of Combined Agglomeration-separationfor Wolframite Fines

The new technology of combined agglomeration-separation and conditions for treating wolframite fineswere discussed. A mixture of wolframite and four kinds of gangue fines (quartz , fluorite, garnet and calcite)can be separated by this new technology. At high feed grade (wolframite : gangue = 1: 1) , wolframite con-centrate obtained by sedimentation assays 6 1 . 22 % ￣ 68. 33 % WO_3 with a recovery of 84. 4 % ￣93. 4 %. Atlow feed grade (wolframite : gangue =1 : 5) , wolframite ocncentrate obtained by combined agglomeration-separation and low-intensity magnetic separation assays 51 . 5% WO_3 with a recovery of 92. 0%. The majorfactors influencing these processes are the dosage of reagents and magnetite used, the time and the speed of agitation.

Influence of surfactants on selective mechanical separation of fine active materials used in high temperature electrolyzers contributing to circular economy

As one of the promising hydrogen production technologies,the development of water electrolysis systems including recycling of their functional components is actively investigated.However,the focus lies on energy and chemical intensive metallurgical operations and less on mechanical separation processes in most studies.Here,an innovative surfactant-based separation process(using CTAB and SDS)is investigated to contribute to developing a selective physical separation process for ultrafine particles used in high temperature water electrolyzers(composed of NiO,LSM,ZrO_(2),and YSZ).Their different surface charge in alkaline solutions influences the adsorption of surfactants on particle surfaces as well as the modification of particulate wettability,which is a key separation feature.Through the observations of changes in surface charge and wetting behavior in the presence of surfactants,a feasibility of liquid-liquid particle separation(LLPS)is evaluated.The performance of LLPS with model particle mixtures shows the potential of selective separation with recovery of NiO in the organic phase,while the rest of the particles remain in the aqueous phase.Perovskite LSM is not considered in this system because it shows a high possibility of being recovered by magnetic separation.The proposed process can be further optimized by increasing the phase separation stages,and further research is needed on the NiO phase,which showed exceptional behavior in the presence of the surfactants.