Strength and Microscopic Characteristics of Tungsten Tailings-based Cementing Material Excited by a Single Alkali under H2SO4 Solution
Aiming at the acid resistance of alkali-activated materials,NaOH and KOH were used as activators,and a tungsten tailings was used as precursor.Three kinds of alkali-solid ratios(the ratio of alkali activator mass to tailings mass)and three kinds of pH solutions were set.The variation of unconfined compressive strength of alkali-activated tungsten tailings-based cementitious materials under the action of H2SO4 solution was analyzed.Combined with scanning electron microscopy(SEM),X-ray diffraction(XRD),fourier transform infrared spectroscopy(FTIR)and inductively coupled plasma optical e-mission spectrometer(ICP-OES)test results,the influence mechanism of H2SO4 solution on the strength of alkali-activated tungsten tailings-based cementitious materials was discussed.The results showed that the softening effect of distilled water on the strength of alkali-activated tungsten tailings-based gel samples is stronger than that of sulfuric acid solution,which is mainly due to the insoluble calcium sulfate and the generated gel covering the surface of the sample to slow down the acid corrosion,and the film-like gel has stronger resistance to acid corrosion than the three-dimensional network gel.The strength of alkali-ac-tivated tungsten tailings-based cementitious material samples under the action of sulfuric acid solution is affected by alkali type,alkali concentration and solution concentration.The research results can provide scientific basis and reference value for the resource utilization of tungsten tailings.