hazardous effects of limastone mining

environmental hazards of limestone mining | education - seattle pi

environmental hazards of limestone mining | education - seattle pi

Limestone deposits exist throughout the world. These alkaline, sedimentary rocks were laid down mostly as deposits on the beds of ancient seas. A valuable natural resource, limestone has many uses in construction, agriculture and industry. Limestone quarries can be above ground or underground, and can cover large areas. Environmental hazards from mining operations depend in part on the location, characteristics and extent of the mining operations.

Limestone deposits exist throughout the world. These alkaline, sedimentary rocks were laid down mostly as deposits on the beds of ancient seas. A valuable natural resource, limestone has many uses in construction, agriculture and industry. Limestone quarries can be above ground or underground, and can cover large areas. Environmental hazards from mining operations depend in part on the location, characteristics and extent of the mining operations.

Limestone mining can affect ground water conditions. Limestone deposits often occur in association with karst, a topography where limestone slowly dissolves away underground. The deposits result in sinkholes, caves and areas of rock fractures that form underground drainage areas. When mining occurs in karst, disruption to natural aquifers, or flows of underground water, can result. Often, mining operations remove ground water to expose the quarrying site, which can lower the water table and change how water flows through the rock formations.

Streams and rivers can be altered when mines pump excess water from a limestone quarry into downstream natural channels. This increases the danger of flooding, and any pollutants or changes in water quality affects the surface water. In Germany, salty water pumped from limestone quarries into rivers has degraded the water quality, according to the International Mine Water Association. Upstream surface water features, such as marshes, ponds and wetlands, can lose volume as their waters drain into the mine and are pumped out.

As water and rock are removed from mines, the support they give to underground features is gone. Sinkholes can develop, where the roofs of underground caverns are weakened or collapse. Collapse can be gradual or sudden. Although natural sinkholes develop over time, man-made ones predominate in mine areas. Sinkhole formation can cease after mine dewatering is stopped and the water table is allowed to return to normal levels.

Limestone mines use two types of blasting. Small explosive charges set along drilled lines free blocks of stone to be removed for construction. Large charges reduce whole areas of limestone to rubble, which is removed for use as crushed stone. The noise, dust, and impact from explosions can result in noise pollution and dust. Underground forces from the blasts can cause sinkholes or change the drainage and water quality of underground aquifers. Construction equipment, such as large trucks, crushing machines and earth-moving equipment, also contribute to noise and dust.

Carolyn Csanyi began writing in 1973, specializing in topics related to plants, insects and southwestern ecology. Her work has appeared in the "American Midland Naturalist" and Greenwood Press. Csanyi holds a Doctor of Philosophy in biology from the University of Wisconsin at Madison.

specific and non-specific hazards in underground mines

specific and non-specific hazards in underground mines

Blasting related hazards must also be added to that list. Although not specific to underground operations, their consequences may be exacerbated by the confined atmosphere and the workplace configuration.

Accidents are always a combination of hazards and causes. Making the issue more comprehensible is the only reason for presenting the hazards listed below. The collapse and flood of underground workings may be a consequence of a dust or gas explosion. Similarly, a fire can cause dust explosion and/or release toxic contaminants.

Fires and explosions have been some of the most destructive and dangerous hazards in the mining industry. It is also one of the most challenging safety issues that miners face. They can occur at any time, whether that's in an active or abandoned facility.

Some of fires can be so devastating that they can ruin entire towns. The town of Centralia, Pa., was evacuated because of a coal mine fire that began in 1962 and has since been burning. The exact cause of the fire has never been determined.

Just like fires, floods can cause just as much devastation in a mine. There are many reasons why mines can become flooded. Some floods are controlled meaning, they are planned. But in other cases, flooding is unintentional. Some of the reasons why floods occur may be:

The Gleision Colliery mining accident took place on Sept. 15, 2011, when seven miners intentionally detonated an explosive. Following the blast, the mine began filling with water. Three of the miners managed to escape. But rescue workers were not able to save the other four, who were trapped and died underground.

After the inrush at Gleision Colliery, the Health and Safety Executive (HSE) in the United Kingdom issued the HID 4-2011 safety bulletin focusing on Regulations 1979 (Precautions Against Inrushes). This regulation was introduced in 1973 after the Lofthouse Colliery accident, Yorkshire, where seven miners were killed after the mine flooded.

Induced Seismicity: Mines located in seismically active regions, such as the Andean region also known to be one of the wealthiest metallic mining zones in the world are particularly at risk. Especially dangerous in underground mining areas, mine-induced seismicity also causes slope instability in surface mining.

Use of Explosives: The use of explosives may cause earthquake-like events that collapse mine workings, and traps miners, as happened to the 33 miners stuck underground from August to October 2010 in a Chilean mine near the city of Copiapo, or kill them, flood the mine and damage structures on the surface.

Layers of coal trap methane a highly explosive gas. Methane can be released, leading to coal dust explosions when there are mechanical errors from tools that are improperly used or that malfunction. When explosives are also detonated intentionally, they can also lead to coal dust explosions.

One of the world's worst coal mining accidents took place at the Benxihu Colliery in Benxi, China. In April 1962, a fire broke out after gas and coal dust exploded. More than 1,500 miners died in the accident.

Timbering / Pillar Failure: Accidents in mines can be presented by properly securing areas in which miners work with pillars and timbers. These timbers support the roof or a tunnel's face during the excavation or lining process. If these are not properly secured, they may lead to collapse.

You can get an idea about the traditional way to timber a mine by reviewing this video.The role of pillars or timbers is obviously key in underground operations.The instability of pillars induced by stress or other unfavorable causes may lead to horrendous cascading pillar failure mechanisms.

Considering the atmosphere underground is limited and confined, the contaminants may include dust, aerosols, diesel fumes and particulates and fumes from blasting, as well as gasses released from the rock strata.Ventilation is key to extract or dilute to a harmless level the toxic contaminants.

Mine-induced seismicity is also another hazard. According to the National Institute for Occupational Safety and Health (NIOSH), many fatalities in underground mines related to explosives were caused by miners being too close to the blast.

Fly-Rocks: Workers struck by rocks, either because they are too close to the blast or because the rock is thrown much farther than expected, remains one of the main causes of accidents both in surface or underground mines.

Explosives Fumes: According to the Dangers of Toxic Fumes from Blasting, surface mine blasters are far more complacent about fumes as those in underground mines. This is because there is a general belief that the open air would cause the fumes to disperse. But toxic fumes can be hazardous regardless of where they occur.

The explosive products used in surface and underground blasting operations produce a variable quantity of toxic gasses. Harmful concentrations of such gasses are more likely to appear in underground confined environments.An efficient, well designed and maintained ventilation system is key to preventing or mitigate this risk.

Premature Blast: This can be due to carelessness or be accidental. Faulty wiring and fuses can also be the cause. The explosive or pyrotechnical products that remain on the ground or in the muck pile might be triggered by any mechanical effect during the digging, milling or crushing stages of the mining process, causing injuries or fatalities to blasters or operators.

Although policies and safety measures continue to be updated to ensure disasters do not take place in mines around the world, there are still precautions the industry can take to ensure hazards are minimized and workers are kept safe.

how does limestone affect the environment?

how does limestone affect the environment?

Limestone mining can pollute water and create sinkholes. When limestone dissolves while it's still in the ground, caves and gullies form, a natural phenomenon known as karst. Although this doesn't hurt the environment in its natural form, once the limestone is mined out, sinkholes can form and disrupt underground waterways. This changes the natural water table. The actual mining process also changes existing waterways, adding additional water to streams and other bodies of water that not only floods the surrounding area, but adds pollutants to it as well. At the same time, it draws water from other features such as lakes and ponds.

Limestone mining can pollute water and create sinkholes. When limestone dissolves while it's still in the ground, caves and gullies form, a natural phenomenon known as karst. Although this doesn't hurt the environment in its natural form, once the limestone is mined out, sinkholes can form and disrupt underground waterways. This changes the natural water table. The actual mining process also changes existing waterways, adding additional water to streams and other bodies of water that not only floods the surrounding area, but adds pollutants to it as well. At the same time, it draws water from other features such as lakes and ponds.

Limestone can be damaged by the environment through weather and water erosion. The stone absorbs water that can cause it to deteriorate over time. If the water has a high acidity content, the damage is more immediate. Wind can wear away stone detailing. Limestone is also prone to discoloration by exposure to oil, dyes or even organic material, such as bird droppings or decomposing plant matter. It can even get rust stains if exposed to oxidizing iron.

Limestone can be damaged by the environment through weather and water erosion. The stone absorbs water that can cause it to deteriorate over time. If the water has a high acidity content, the damage is more immediate. Wind can wear away stone detailing. Limestone is also prone to discoloration by exposure to oil, dyes or even organic material, such as bird droppings or decomposing plant matter. It can even get rust stains if exposed to oxidizing iron.

environmental hazards of limestone mining and adaptive practices for environment management plan | springerlink

environmental hazards of limestone mining and adaptive practices for environment management plan | springerlink

Limestone is a fundamental raw material in various industrial sectors. It is formed due to biochemical precipitation of calcium carbonate, and further compaction over long periods of time. A high market for limestone products and its use in a growing number of industries has led to its widespread exploration and excavation. The most widely adopted method of limestone mining is through opencast pits with bench formation. Limestone mining causes widespread disturbance in the environment. Myriad impacts are observed as changes in land use pattern, habitat loss, higher noise levels, dust emissions and changes in aquifer regimes. These environmental concerns have brought about the need for sustainable Environment Management Plan in the mining sector, so as to reduce environmental degradation during operation as well as restoration of degraded lands after final mine closure. A well-formulated Environment Management Plan will help in mitigating the impacts of mining on the environment. The best practices adopted by industries around the world can be adapted as per site characteristics is to ensure sustainable mining along with the prevention of environmental degradation.

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