**Preface to "Current Status of Low-Grade Minerals and Mine Wastes Recovery: Reaction Mechanism, Mass Transfer, and Process Control"**

This reprint focuses on chemical/bio-leaching and utilization of low-grade minerals, solid wastes, and tailings in metal mines. It will provide a good reference for researchers in the fields of mining engineering, mineral processing engineering, hydrometallurgy, etc. Thank you very much to the MDPI editors and reviewers for their tremendous support and assistance to guest editors and authors in this editing process. Last but not least, the author's academic ability is limited, and we sincerely hope that readers can provide criticism and valuable suggestions.

#### **Shenghua Yin and Leiming Wang**

*Editors*
