Recycling Dam Tailings as Cemented Mine Backfill: Mechanical and Geotechnical Properties

Abstract

As a result of developing technology and scientific studies, employing dam tailings as critical raw material and vital economic reserve has become widespread recently. Employing dam tailings as a main ingredient of CPB (cemented paste backfill) can offer benefits to mining operations. This study deals with the use of dam tailings in CPB, considering the mechanical and geotechnical aspects. CPB was prepared at fixed solid and cement contents (72%, and 5%, respectively) and tested for different cure ages varying from 3 to 56 days. The results disclosed that the strength of filling increased over time, with the exception of 56-day cured CPB having high sulfur minerals where strength decreased sharply. The reasons behind these strength surges could be clarified by CPB’s basicity, which quickens the hydration of cement. Voids between tailings grains are also occupied by hydration products, resulting in the high strengths. Due to the fact that higher sulfate contents can cause lower pH values within CPB, this is one of the factors that should be considered for the backfill’s strength performance. The cement tends to increase the backfill’s pH in short term, but pH of long-term cured backfills decreases because of dam tailings which is inclined to acid formations and erosions. This is a sign that the deformation properties of CPB are deteriorated. Depending on curing time, CPB’s water content and void ratio decrease, but their surface areas increase. The resulting data will endow to better apprehend the effects of dam tailings on CPB quality integrating cost and quality.

The Experimental Investigation on Mechanics and Damage Characteristics of the Aeolian Sand Paste-like Backfill Materials Based on Acoustic Emission

“…The higher the loading rate, the shorter the time internal defects are compacted, so it enters the linear elastic stage faster. The filling specimens have ductile failure characteristics and have residual strength after the peak [ 48 , 49 ]. In Figure, the stress–strain curve corresponding to 0.0050 mm/s appeared with two small peaks after the peak failure stage, indicating that ASPM specimens still have strong bearing capacity after reaching the peak failure [ 50 ].…”

Study on Natural Settlement Index Characteristics of Iron-Bearing Tailings Applied to Goaf Filling Treatment

“…The different factors affecting the properties of the backfill materials can be analyzed. The properties can be improved to achieve a better forcing environment for the goaf [26,27]. With consideration of the costs of all of the materials, in this study, tailings subsidence experiments were conducted to verify the natural subsidence characteristics of the tailings.…”

Vegetation as an ecological indicator in assessing environmental restoration in mining areas

“…This case serves as a pertinent example, given the high-frequency mining operations at the Ta’ershan Mining Area during the early years of the 21st century. These mining operations led to an escalation in mining waste discharge and significant land occupation 13 , 14 , 15 all contributing to noticeable environmental damage. It’s worth mentioning that a major tailings pond failure accident occurred in 2008 at the Ta’ershan Mining Area, due to frequent mining activities and the exceeding capacity of the tailings ponds, compounded by a lack of effective management: the Xiangfen tailings pond failure accident, also known as the Xinta Mining Company Limited Ta’ershan iron ore mine tailings pond failure accident, took place on September 8 th , 2008, in Ta’ershan Mining Area, Taosi Township (approx.…”