In gold beneficiation, grinding is a critical stage that determines the degree of gold mineral liberation and subsequent recovery rates. For a wet closed-circuit grinding system with a processing capacity of 5 tons per hour (5 t/h), the rational selection of equipment parameters and models is essential.

First, the core system parameters must be defined. Feed particle size generally needs to be controlled at ≤25 mm, while the required discharge fineness ranges from 0.074 mm to 0.4 mm to ensure adequate liberation of gold minerals. In a wet closed-circuit process, the ball mill operates in conjunction with classification equipment (such as a spiral classifier or hydrocyclone); the classifier separates material meeting the fineness requirements, while coarse particles are returned to the ball mill for regrinding, thereby ensuring grinding efficiency and consistent product fineness. Regarding motor power, considering the 5 t/h capacity and the load characteristics of wet grinding, a motor in the 37–45 kW range is recommended to ensure stable operation while maintaining an appropriate power margin.

Second, suitable ball mill models should be selected. For a capacity of 5 t/h, ball mills with shell diameters between 1.2 m and 1.5 m are appropriate. Ideal choices include wet grate-discharge ball mills with specifications such as Φ1200×4500 or Φ1500×3000. These models typically feature a grinding media charge of 5–11 tons and a shell rotation speed of 27–32 r/min, providing sufficient grinding energy while avoiding over-grinding. Furthermore, wet grate-discharge ball mills offer rapid discharge and minimal over-pulverization, making them particularly well-suited for closed-circuit grinding systems and effective at enhancing gold recovery rates.

Additionally, equipment selection must account for liner materials and the ratio of grinding media. Wear-resistant rubber or high-manganese steel liners are recommended to reduce wear-related costs. The steel ball charge ratio should be dynamically adjusted based on ore hardness; an initial mix of large, medium, and small balls can be used, followed by optimization based on actual grinding performance.

In summary, the success of a 5 t/h wet closed-circuit gold grinding system hinges on the proper matching of parameters and the selection of appropriate equipment models. Through scientific parameter settings and appropriate equipment selection, efficient and stable grinding operations can be achieved, laying a solid foundation for subsequent beneficiation processes.