In recent, the placement of backfill in underground mines has emerged as a new paradigm in research as it not only improves safety but also allows disposal of byproducts including coal ash. In this regards, this paper addresses the backfilling challenges in limestone mine to prevent sinkhole and subsidence. Limestone mines, generally regarded as being safer than coal and metal mines, have been ...

Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite m...

Limestone can be an option for sulfate sorption, particularly from neutral mine drainages because calcium ions on the solid surface can bind sulfate ions. This work investigated sulfate removal from mine waters through sorption on limestone. Continuous stirred-tank experiments reduced the sulfate concentration from 588.0mg/L to 87.0mg/L at a 210-min residence time. Batch equilibrium tests showe...

The Christmas copper mine is in the Banner mining district, Gila County, Arizona. It is 8 miles north of Winkelman and 22 miles south of Globe. The mine was opened in 1905; to the end of 1943 it had produced about 55,340,000 pounds of copper. In 1946 it was operated under lease. The ore is high-lime fluxing ore, required by the smelter at Hayden. The ore produced during 1942 averaged 2.16 perce...

Based on differences in the permittivity of coal and limestone rock, a resonant cavity measurement technique is presented for the rapid determination of the proportions of coal and limestone in powdered mixtures. The ratio of the resonant frequency shift and the change in the transmission factor when mixed coal and limestone samples are inserted into the cavity provides a means for estimating t...

Coal dust explosions in underground coal mines are pre­ vented by a generous application of rock dust (usually lime­ stone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents fl ame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of ex­ plosion experiments using various coal dust and limes...

To develop a quantitative exposure-response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,3...

Vertical flow systems (VFS) are a type of passive treatment unit process in which acid mine drainage (AMD) flows vertically through layers of organic matter and limestone. Located in the coal belt of eastern Oklahoma, the Red Oak VFS was constructed to address AMD exiting an abandoned underground coal mine. The passive treatment system consists of five cells, alternating between surface flow (c...

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protoco...