The suitability of landfill-mined-soil-like-fraction (LFMSF), which is a major constituent of landfill-mined residues, as a pH buffer material has been established by earlier researchers. Incidentally, this would promote the utilization of LFMSF as an anthropogenic (manmade) resource for treating acidic soils and neutralization of extreme pH industrial by-products such as red mud, phosphogypsum, incineration ash, etc. However, the apprehension is that when LFMSF reacts with materials of extreme pH, the leaching of heavy metals present in it might get enhanced/accelerated, which needs to be understood thoroughly to avoid any possible geoenvironmental contamination, by considering pH-dependent leaching of heavy metals present in it. Moreover, it is worth noting that such a study should give priority to pH stabilization, whose value will be influenced by processes such as dissolution, sorption, desorption and precipitation during the addition of H+ or OH−. Unfortunately, the time required for pH stabilization has not been considered by the existing studies. Hence, the present study was conceived to establish the time required for pH stabilization when the LFMSF reacts with acid/base of different concentrations. Following this, the concentration of leachable elements from LFMSF, at the end of the pH stabilization, was determined for the samples obtained from different landfill mining sites in India. It is believed that such a study would help in understanding the pros and cons of utilizing LFMSF as a sustainable anthropogenic resource for the neutralization of industrial by-products with extreme pH conditions.