Some of the most difficult coal mine roof in the United States can be found in the Illinois Basin. Factors contributing to the high roof fall rate include weak, moisture-sensitive roof rock; high horizontal stress; and limited longwall mining. The depth of cover ranges from 27 to 300 m (90 to 1,000 ft), and roof damage from horizontal stress can be severe. Moisture-sensitive roof rock, which co...

BACKGROUND The mortality experience over 22-24 years of 8,899 working coal miners initially medically examined in 1969-1971 at 31 U.S. coal mines was evaluated. METHODS A cohort life-table analysis was undertaken on underlying causes of death, and proportional hazards models were fitted to both underlying, and underlying and contributing causes of death. RESULTS Elevated mortality from nonv...

There are many sources trough which the soil get enriched and contaminated with REEs. The determination of REEs in environmental samples has been limited because of the lack of sensitive analytical techniques. Soil samples were collected from four sites including open cast coal mine, natural coal burning, coal washery and control in the coal field located in Dhanbad, India. Total concentrations...

The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the conce...

Fatalities caused by highwall/spoilbank failure in the surface mines, coal and non-metal, increased to an alarming rate of seven during 1999. To determine the causes of slope failure and successful mining practices, the National Institute for Occupational Health and Safety undertook a study. The study included: 1. A review of accident statistics; 2. A review of Federal and state mining laws per...

this paper tries to determine an optimum condition for the flotation operation of the alborz-sharghi coal washing plant. for this purpose, a series of comprehensive experiments have been conducted on representative samples from feed of the flotation system of the plant. four operational variables such as the collector dosage (fuel oil), the frother dosages (mibc), the pulp density percent and t...

background : in china, over 80% of all work-related deaths in the mining industry occur in coal mines and human factors constitute 85% of the direct causes of coal mine accidents, which indicates that significant shortcomings cur-rently exist in the safety behavior management of chinese coal mine workers. we aimed to verify the impact of human psychological behavior in coal mine accidents syste...

and ECA coal analysers have been used to control sorting and blending operations at coal mines, power plants and coal terminals. In sorting operations, the analyser results are used to sort coal into piles, bins or silos based on the measured quality. Coals can be sorted by the ash, sulphur, moisture, heating value, or by combinations of these. Sorting can be used to allow low-ash coals to bypa...

The subsoil of Morocco is marked by a wealth mineral resources (phosphate, lead, zinc, coal and others). For this reason, the mining sector still considered one main pillars national economy. Moroccan lead deposits are located mainly in Atlas region Eastern region. Zellidja smelter company has succeeded distinguishing itself being among best smelters Morocco. It known nationally internationally...