本研究提出了一种利用煤矸石(CG)活化和预热脱碳活化煤CG基胶凝回填材料(PCCPB)实现绿色开采的新思路。用预热脱碳煤CG(PCG)制备PCCPB,FA,活化剂,低剂量水泥,和水。该思路实现了煤质CG固体废弃物的规模化处置和资源化利用。CG的脱碳和活化通过预热燃烧技术在900°C的燃烧温度和4分钟的脱碳活化时间下将材料压碎至小于8mm。采用综合测试(包括力学性能测试,微观测试,和浸出毒性测试)。结果表明,C-S2、C-S3和C-S4的单轴抗压强度(UCS)能够满足充填开采的要求,其中固化时间为3d和28d的C-S3的UCS分别为0.545MPa和4.312MPa,分别。Na2SO4在不同的固化时间激发PCCPB,PCCPB的UCS随着Na2SO4用量的增加而增加,3%的Na2SO4对PCCPB后期强度(28d)的激发效果最好。所有组(对照组和CS1-CS4组)渗滤液重金属离子均符合地下水III类标准的要求,和PCCPB对重金属离子的稳定/凝结具有积极作用(Mn,Zn,As,Cd,Hg,Pb,Cr,Ba,Se,Mo,和公司)。最后,利用FTIR对PCCPB的微观结构进行了分析,TG/DTG,XRD,和SEM。该研究对促进煤CG残碳的资源化利用,实现煤CG活化的大规模可持续消耗具有重要意义。
This
study proposes a novel idea of the use of coal gangue (CG) activation and preheated decarburized activated coal CG-based cemented paste backfill material (PCCPB) to realize green mining. PCCPB was prepared with preheated decarburized coal CG (PCG), FA, activator, low-dose cement, and water. This idea realized scale disposal and resource utilization of coal CG solid waste. Decarbonization and activation of CG crushed the material to less than 8 mm by preheated combustion technology at a combustion temperature of 900 °C and a decarbonization activation time of 4 min. The mechanism of the effect of different Na2SO4 dosages on the performance of PCCPB was investigated using comprehensive tests (including mechanical property tests, microscopic tests, and
leaching toxicity tests). The results show that the uniaxial compressive strength (UCS) of C-S2, C-S3, and C-S4 can meet the requirements of backfill mining, among which the UCS of C-S3 with a curing time of 3 d and 28 d were 0.545 MPa and 4.312 MPa, respectively. Na2SO4 excites PCCPB at different curing time, and the UCS of PCCPB increases and then decreases with the increase in Na2SO4 dosage, and 3% of Na2SO4 had the best excitation effect on the late strength (28 d) of PCCPB. All groups\' (control and CS1-CS4 groups) leachate heavy metal ions met the requirements of groundwater class III standard, and PCCPB had a positive effect on the stabilization/coagulation of heavy metal ions (Mn, Zn, As, Cd, Hg, Pb, Cr, Ba, Se, Mo, and Co). Finally, the microstructure of PCCPB was analyzed using FTIR, TG/DTG, XRD, and SEM. The research is of great significance to promote the resource utilization of coal CG residual carbon and realize the sustainable consumption of coal CG activation on a large scale.