Research Progress and Prospects for Lubricant Additives for Water-Based Hydraulic Fluids in Hydraulic Supports

Water-based hydraulic fluids serve as the power transmission medium for hydraulic support systems in coal mines, and the performance of their lubricant additives directly affects the stable operation of the supports. This paper provides a systematic review of research progress on lubricant additives for water-based hydraulic fluids in China, focusing on two main categories: liquid and nanoparticle lubricant additives. Liquid lubricant additives are categorized into fatty alcohol ether-based, vegetable oil-based, and ionic liquid-based additives; nanoparticle-based additives include inorganic nanoparticles and organic–inorganic composite particles. This article analyzes the molecular structure design strategies, lubrication mechanisms, and performance regulation pathways of various additives. In response to the demands of intelligent coal mining and green mine construction, it is proposed that the development of lubricant additives for water-based hydraulic fluids should target multifunctional integration and environmental friendliness. Improvements in the quality of the dilution water and the maturity of cylinder anticorrosion technology will create favorable conditions for the development of single-component (or few-component) hydraulic fluids. In the future, research should deepen understanding of the structure–performance relationships of lubricant additives, so as to facilitate the engineering application of high-performance, low-dose, degradable green lubricant additives and provide technical support for intelligent coal mine construction and ecological protection in the Yellow River Basin.