煤泥水可称为选煤厂的“血液”，循环煤泥水系统则是选煤厂的“血液循环系统”。为深入了解选煤厂的循环煤泥水系统，提出了选煤水化学的概念，并通过介绍循环煤泥水系统的物质组成、无机盐类矿物的溶解、煤中无机硫的氧化、金属离子的水解与聚合、煤泥水的酸碱反应、黏土矿物对金属离子的吸附，全面解析了循环煤泥水系统的水化学性质。煤中矿物组成是影响水化学性质的关键因素，循环煤泥水系统中的一系列化学反应使煤泥水的水化学性质发生变化，包括离子组成与含量、煤泥水的酸碱体系、离子的存在形式。黏土矿物对金属离子的吸附对水化学性质有重要影响，金属阳离子在黏土矿物上的吸附形式包括静电吸附、羟基络合吸附、沉淀吸附，并从理论角度分析金属离子在黏土矿物上的吸附形态，同时其吸附过程也受pH的影响，最终使煤泥水中高价金属离子含量减少。通过反应原理、影响因素和实验模拟分别对各个反应过程进行分析，总结了多种反应之间的关联性，得出以上多个因素之间是相互影响、相互制约的，共同决定了循环煤泥水系统的水化学性质。循环煤泥水系统的水化学性质研究是实现高效选煤的基础，得出不同煤样和水质环境条件下的水化学性质变化规律，实现水化学性质的精准调控，可以有效改善煤泥浮选和煤泥水沉降效果。

Coal slime water could be called the “blood” of coal preparation plant,and the circulating coal slime water system is the “blood circulation system” of coal preparation plant.In order to systematically introduce the properties of the circulating coal slime water system of the coal preparation plant,the concept of water chemistry in coal preparation is proposed.The water chemistry properties of circulating coal slime water system are com prehensive understood by introducing the material composition of circulating coal slime water system,the disso lution of inorganic salt minerals,the oxidation of inorganic sulfur in raw coal,the hydrolysis and polymerization of metal ions,the acid base reaction of coal slime water,and the adsorption of metal ions by clay minerals.The mineral composition of raw coal is a key factor affecting the water chemistry properties.The water chemistry properties are changed after a series of chemical reactions in the circulating slime water system,including ions composition and content,acid base system of coal slime water,and occurrence mode of ions.The adsorption of metal ions by clay minerals has an important impact on water chemistry properties,which ultimately makes the content of high valent metal ions reduced in coal slime water.The adsorption form of metal cations on clay minerals includes electrostatic adsorption,hydroxyl complex adsorption and precipitation adsorption.The adsorption forms of metal ions on clay minerals are analyzed theoretically.At the same time,the adsorption process is also affected by pH,which ultimately reduces the content of high valent metal ions in the coal slime water.Through the reaction principle,influencing factors and experimental simulation,each reaction process is analyzed separately,and the correlation between the various reactions is summarized.It is concluded that the above multiple factors influence and restrict each other,which collectively determine the water chemistry properties of the circulating coal slime water system.The understanding of the water chemistry properties of the circulating slime water system is the basis for efficient coal preparation.The changing law of water chemistry under different coal samples and water quality environmental conditions can be obtained.The precise control of water chemistry properties can effectively improve the coal slime flotation and coal slime water settlement.