细粒铁尾矿固化造块及其机制的研究

Study on Solidification and Agglomeration of Fine Iron Tailings and Its Mechanism

以工业固体废弃物X及其激发剂Y、Z为固化剂,固化细粒铁尾矿,经压制成型制备固化块。考察了固化剂原料配比、用量、成型压力和养护龄期对固化块力学和耐水性能的影响,并采用X射线衍射、压汞测孔法和电镜扫描研究了其高强和耐水机制。结果表明,制备所得的尾矿固化块综合性能优良,当固化剂和尾矿掺量分别为12.7%和87.3%,成型压力为50MPa,自然养护7d后,所得尾矿固化块抗压强度和吸水饱和抗压强度分别为12.4MPa和3.4MPa,符合矿山填充要求。理论分析表明,增大成型压力,减小了固化块的平均孔径,促进了水化反应,有利于生成起粘结作用的水化硅酸钙和钙矾石晶体加固结构,从而提高固化块强度和耐水性能。该尾矿固化技术用于矿山充填塌陷区是经济可行的,具有实用价值。

Curing blocks of the fine iron tailings were prepared by press forming using industrial solid waste X as cementing material and Y,Z as activators.The effects of the ratio and content of curing agent,molding pressure and curing age on the mechanical property and water resistance of the blocks were investigated.The mechanism of high strength and water resistance of the blocks were studied by X-ray diffraction,mercury intrusion porosimetry and scanning electronic microsopy.The results indicated that the physical performance of blocks was good,when the mixing amount of the iron tailings and curing agent was 12.7%and 87.3%respectively,the forming pressure was 50 MPa,after 7days nature curing,the compressive strength and water absorption saturated compressive strength of the blocks reached 12.4MPa and 3.4 MPa respectively,which met the requirements for the backfilling.The theoretical analysis showed that inceasing molding pressure could reduce the average pore diameter and promote the hydration speed,which favored to generate calcium silicate hydrate as binder and ettringite as consolidation structure,so as to enhance the performances on machanics and water resistance.The technology of curing iron tailings to fill in the caved areas was economically feasible with practical value.