Abstract: Particle-bubble mineralization is the core step of the flotation process. Due to their low momentum and weak inertia, microfine mineral particles tend to follow streamlines and flow around bubbles, making effective particle-bubble collision difficult. In addition, micro-fine particles lack sufficient energy to overcome the micro-hydrodynamic resistance of the liquid film at the gas-solid interface. This results in poor drainage and rupture efficiency, weak particle-bubble attachment, and consequently low mineralization recovery, directly limiting flotation efficiency and performance. Focusing on the “interfacial micro-hydrodynamic resistance effect” in the particle-bubble attachment and incorporating the turbulent vortex intensification mechanism during particle-bubble collision, the concept of generalized confined space was introduced into the flotation mineralization process. A high-energy-dissipation confined turbulent-vortex mineralization process was developed, together with a novel flotation mode integrating “confined mineralization and unconfined separation”. A pilot-scale experimental system was subsequently constructed using coal gasification fine slag as the test material. Computational fluid dynamics (CFD) simulations were employed to analyze the hydrodynamic characteristics of the confined turbulent-vortex mineralization system, while carbon-ash flotation separation experiments were conducted to verify its feasibility. The results indicated that the synergistic interaction of pipe flow, impinging flow, and stirring flow within the proposed confined turbulent-vortex mineralization system induced a high-energy-dissipation turbulent flow field and generated small-scale turbulent vortices. Meanwhile, the pressurized confined-space design increased the system pressure and established a high-pressure mineralization environment. Impeller rotational speed was identified as the dominant factor affecting flow structure and turbulent energy dissipation within the confined turbulent-vortex mineralization system. As rotational speed increased, the Kolmogorov vortex scale decreased from 35.19 μm to 19.37 μm. In contrast, confined pressure had little influence on flow velocity and turbulent dissipation distributions but significantly increased the system pressure. Within the investigated range, increasing impeller rotational speed effectively improved the carbon-ash flotation separation performance of coal gasification fine slag. When the impeller speed reached 432 r/min, carbon recovery approached a plateau. Increasing confined pressure promoted the mineralization process between micro-fine carbon particles and bubbles, thus improving carbon recovery. Under high confined-pressure conditions, appropriately reducing frother dosage further enhanced the mineralization of micro-fine carbon particles and improved carbon recovery. The optimal separation performance was obtained at an impeller rotational speed of 432 r/min, a confined pressure of 0.06 MPa, and a frother dosage of 2.5 kg/t, corresponding to a carbon recovery of 90.55% and a tailing ash content of 98.91%.