Perpustakaan Digital ITB

The extraction of gold from sulphide ores using cyanide leaching is a wellestablished process in the metallurgy industry. However, the sulphide ore is required roasting process to obtain high recovery rate. As a result, fluidized-bed technology has been widely used for roasting. This study focuses on investigating air-particle interaction in continuous fluidized bed reactors for gold sulphide ore using CFD simulation. The reactor used for simulation is a continuous fluidized-bed reactor with a height of 10.8m, freeboard diameter of 9.5m, and bed diameter of 7.3m. The bottom section of the reactor has a wind box and distributor plate. The wind box has a center inlet and 4 side inlets that supported air to the distribution plate and distribute to the top section of the reactor. The top section of the reactor has one feed inlet for slurry, one product outlet, and one gas outlet. Because the reactor that has been used for simulation is industrial scale, it has a relatively complex geometry. Thus, to reduce the computational time but get representative results, the reactor was simplified and divided into two sections. The top section is 2D and the bottom is section 3D. The simulation consists of 11 variants. Each variant is divided into two stages. The first stage is simulating the air blower that will be in contact with the distribution plate before being injected inside the reactor. The second stage is the interaction of air and particle inside the reactor. First-stage simulation and secondstage simulation were simulated separately from the first-stage simulation because of concerns about reducing simulation complexity and having different analysis targets. The first stage simulation was carried out using Fluid Flow CFX and the second stage was carried out using Fluid Flow Fluent with a Hybrid of Eulerian- Eulerian multi-phase model and discrete phase model (HEEDPM). The result of this simulation provides insights into operational conditions related to air-particle interaction. The simulation result exhibits the closest approximation to the existing design is simulation 4 with average volume 0.0637 faction and the 97.6% success of roasting.