Ore washing is often necessary in the following situations:

(1) For hematite and limonite with high clay content, if the cementing clay contains very little iron minerals, the mud can be discarded as final tailings after washing, thus improving the grade of the ore.

(2) For placer tin ore, washing can separate coarse, mineral-free waste rock, and the resulting fine particles can be deslimed before beneficiation.

(3) When ore requires hand sorting or photoelectric separation, but the mud contaminates the ore surface, making it difficult to identify, washing is necessary before hand sorting or photoelectric separation.

(4) When ore contains a lot of mud, which frequently clogs crushers, screens, and ore bin openings, making continuous production difficult, washing can be used to address this.

(5) For some ores, the primary mud and ore differ significantly in beneficiation properties (e.g., floatability, magnetism). Washing separates the mud and sand, allowing for separate processing and achieving better beneficiation indicators.