4. FLOTATION PROCESS MODELLING 4.1 Flotation process modelling approach A Floatability Component Model (FCM) approach, developed as part of the AMIRA P9L project, was used to describe the flotation process at Ernest Henry Operations. The overall recovery of a mineral i (Ri) is a function of froth recovery (Rf), water recovery (Rw), cell residence time (t), degree of entrainment (ENT) and the pulp rate constant (kc). = R (1 - R ) + ENT R (1 + R ) (1 - R ) + ENT R Where kc = P*Sb denotes the floatability of an ore for a defined pulp environment and operating conditions, and Sb represents the bubble surface area flux (bubble surface area per unit time per unit cell cross-sectional area). The floatability component (P) is a set of particles that exhibit a similar flotation rate under fixed operating conditions and a fixed chemical environment (Lynch et al., 1981). The floatability parameters, including the number of components required to describe each mineral, the flotation rate constant, and the proportion of each mineral in each component, are determined by non-linear regression of the recovery equation and plant survey dataset. 4.2 Pre-installation - modelling and simulation for project justification Aiming to simulate the performance of a full‑scale flash flotation unit and assess its potential impact on recirculating loads and overall circuit performance, a floatability component model was developed for the Ernest Henry Operations flotation circuit. Simulation provided a platform for trade‑off analysis, supporting a cost–benefit evaluation to validate the viability of the project. Data from the SkimAir® pilot unit (SK0.25) was used to estimate flash flotation performance. Given the small size of the pilot unit relative to the plant’s cyclone underflow stream and particle size distribution, some degree of feed bias was possible. Significant effort was therefore directed toward configuring the spear sampler to minimise particle segregation, and particle size distribution analysis was undertaken to confirm that the sampler produced a representative feed for the flash cell. Following development of the floatability component model, a simulator incorporating a full‑scale flash flotation unit (Metso SkimAir® SK240) into the regrind circuit was calibrated in JKSimFloat. The simulator was then used to predict circuit performance under various operating scenarios. Multiple simulations were conducted to evaluate the potential benefits and impacts of the SkimAir® installation on copper and gold recovery and grade. The key considerations for the pre-installation simulation stage are as follows: 1. Impact on copper reporting to the cleaner circuit:
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