为研究煤矸石在淋溶作用下产酸/产碱过程的化学动力学参数,以辽宁阜新矿区新鲜煤矸石为研究对象,采用改进的静态淋溶实验方法,对三种不同矿物组分煤矸石在淋溶过程中的产酸/产碱速率进行了实验研究。结果表明:淋溶作用下煤矸石的产酸/产碱过程可分为快速和慢速两个时期。快速期内产酸/产碱速率分别受硫铁矿及方解石矿物含量的影响;慢速期内的产酸/产碱速率分别受其他硫化物和硅酸盐矿物含量的影响。经计算,实验所用三种煤矸石的快速产酸速率分别为5.184、3.504、4.465mmol·kg^-1·day^-1;慢速产酸速率分别为0.256、0.844、0.395mmol·kg^-1·day^-1;快速产碱速率分别为8.64、6.16、6.72mmol·kg^-1·day^-1;慢速产碱速率分别为0.109、0.320、0.429mmol·kg^-1·day^-1。煤矸石淋溶液酸碱性演化过程可根据影响表观pH值的矿物成分划分为方解石碱性期、硫化物产酸期、硅酸盐滞后产酸期和硅酸盐产碱期四个阶段,但受不同煤矸石所含矿物组分的差异的影响,上述四个时期的持续时间各异。
In order to study the chemical kinetics parameters in coal gangue acid/alkali production process in the leaching effect, taking the fresh coal gangue from Fuxin coal mine of Liaoning Province as the study object, adopting an improved static leaching method, experimental study of acid/alkali production rate in the leaching effect for coal gangue composed of three different mineral components was carried out. Results indicate that coal gangue acid/alkali production process in the leaching effect can be divided into two periods: fast period and slow period. During the fast period, the acid/alkali production rate is obviously affected by pyrite and calcite content, respectively, while during the slow period, the acid/alkali production rate is obviously affected by content of other sulfide minerals and silicate, respectively. The calculated acid production rates of three coal gangue samples used in experiments are 5. 184, 3. 504, 4. 465mmoi·kg^-1·day^-1, respectively, during fast period, and 0. 256, 0. 844, 0. 395mmol·kg^-1·day^-1 , respectively, during slow period. The calculated alkali production rates are 8.64,, 6. 16, 6.72retool ·kg^-1·day^-1 , respectively, during fast period, and 0. 109, 0.320, 0.429mmol·kg^-1·day^-1 , respectively, during slow period. According to the mineral components affected PH value, coal gangue leaching solution pH evolution can be divided into four phases, calcite alkaline phase, sulfide acid phase, silicate acid phase lag and silicate alkali phase lag. However, the duration of above four periods is different due to the different mineral components in coal gangues.