Noise Control In Underground Mining

Author: Audrie Koinzan

Publisher:

ISBN:

Category:

Page: 140

View: 776

The effects of noise manifest themselves in human cost and suffering and add to the cost of doing business. Noise poses a serious threat to the health and well-being of society, and recent studies have demonstrated that environmental noise, including noise at the workplace, causes direct and indirect adverse health effects to workers. It is now recognized as a hazard to workers' safety and health in a variety of industries. If you want to know more about the engineering noise control methods that are currently being used across the world in the mining industry, then keep reading. This book about noise pollution provides a good introduction of the main topics in the area of noise control. A good starting point for graduate students and managers for additional and focused exploration!

Noise Control In Underground Mining

Author: Lee Barker

Publisher:

ISBN:

Category:

Page: 140

View: 496

The effects of noise manifest themselves in human cost and suffering and add to the cost of doing business. Noise poses a serious threat to the health and well-being of society, and recent studies have demonstrated that environmental noise, including noise at the workplace, causes direct and indirect adverse health effects to workers. It is now recognized as a hazard to workers' safety and health in a variety of industries. If you want to know more about the engineering noise control methods that are currently being used across the world in the mining industry, then keep reading. This book about noise pollution provides a good introduction of the main topics in the area of noise control. A good starting point for graduate students and managers for additional and focused exploration!
Technology & Engineering

Noise Control in Underground Metal Mining

Author: Department of Health and Human Services

Publisher: CreateSpace

ISBN:

Category: Technology & Engineering

Page: 70

View: 375

Noise-induced hearing loss (NIHL) is the most common occupational illness in the United States, with 30 million workers exposed to excessive noise levels every day. Of particular concern is the mining industry; which has the highest prevalence of hazardous noise exposure of any major industry sector and is second only to the railroad industry in prevalence of workers reporting hearing difficulty. This document is for operators, safety personnel, and mechanics in the mining industry who are not specialists in noise control engineering or acoustics. Evaluations of successful and unsuccessful attempts at controlling noise on several large, underground metal mining machines are detailed to illustrate the basic principles of noise control. Once personnel understand the guidelines and principles of noise control, they will be able to evaluate the extent of a noise problem; determine the best approach to the problem; and apply the most appropriate solution. Because of the insidious nature of NIHL, it can go unnoticed until a considerable loss of hearing has occurred. In some cases, diagnosis is delayed because an exposed individual claims to have become accustomed to the noise. In reality, that person may have already suffered irreversible hearing loss.
Mineral industries

The Bureau of Mines Noise-control Research Program

Author:

Publisher:

ISBN:

Category: Mineral industries

Page: 85

View: 995

This report summarizes the Bureau of Mines noise-control research program from 1972 to 1982. Each segment of the mining industry--under- ground coal, underground hardrock, surface mining, and processing plants--has different noise-control problems because of vast differences in working procedures, equipment, and workplace design. The Bureau has identified the most serious noise problems in each segment and has developed strategies for attacking these problems. This publication points out the need for noise control in the mining industry, discusses Federal regulations governing worker exposure to noise, and describes the Bureau's overall approach to mining noise- control research. It traces the history of noise overexposure in each segment of the mining industry and discusses the major noise sources. It provides detailed information on noise-control research efforts in the Bureau's major areas of emphasis, including the results of these efforts. Finally, the report discusses the Bureau's future role in research on mining noise control, emphasizing the need to expend more effort on long term in-house investigations into the noise problems that have been identified in past programs as the most serious ones.
Technology & Engineering

Noise Control in Underground Metal Mining

Author: Efrem R. Reeves

Publisher: CreateSpace

ISBN:

Category: Technology & Engineering

Page: 70

View: 314

This document is for operators, safety personnel, and mechanics in the mining industry who are not specialists in noise control engineering or acoustics. Evaluations of successful and unsuccessful attempts at controlling noise on several large, underground metal mining machines are detailed to illustrate the basic principles of noise control.

Active Noise Control of Stageloader Noise in Longwall Mining

Author:

Publisher:

ISBN:

Category:

Page: 22

View: 544

With the large-scale mechanization inherent to the mining industry, noise-induced hearing loss remains a major concern. As part of on-going efforts to develop engineering controls to reduce noise levels in longwall mining, active noise control experiments were conducted above ground on a modified non-working stageloader. Recorded underground stageloader noise was broadcast into the above ground stageloader. The result was an average 7 dBA reduction when the active noise control was applied. These results suggest the possibility that active noise reduction can be a useful means to reduce stageloader noise if the control system can be made sufficiently rugged. The study was divided into two phases. First, underground noise surveys were carried out at two different mines. The second phase of the study were the Active Noise Cancellation (ANC) experiments on the above ground non-operational stageloader.
Deafness, Noise induced

Noise Control in Underground Metal Mining

Author: Efrem R. Reeves

Publisher:

ISBN:

Category: Deafness, Noise induced

Page: 62

View: 713

"Engineering noise controls are the preferred solution to a noise problem because they address noise sources directly. Administrative controls and personal protective equipment should be explored as secondary solutions. Basic noise controls include barriers and sound-absorbing materials. A barrier is a solid obstacle that is somewhat impervious to sound and that interrupts the direct path from the sound source to the receiver. For the best reduction in sound level, the barrier should be: 1. placed as close as possible to either the source or receiver; 2. assembled to be as tall and wide as practical so it extends well beyond the direct source-receiver path; and 3. constructed of a material that is solid and airtight. Sound-absorbing treatments reduce reflections and the resulting echoes and reverberation. Usually, these materials are porous. Compared to high frequency sounds, low frequency sounds are more difficult to absorb with materials and to block with barriers. Therefore, it is important to know the frequency content for a particular noise problem. The effectiveness of barriers and absorptive materials as noise controls on mining equipment was tested during field studies. Following are some of the key findings. 6.1 Haul Trucks: The use of absorptive materials in the operator's area of tested haul trucks had very little effect on sound levels underground. Sound level reductions were on the order of 1 dB(A). Most of the sound reaches the operator via the direct path from the noise source to the operator. In addition, noise reflects from the walls to the operator station. Open cabs allow the direct and reflected sound to enter the operator station. Therefore, a large reduction in sound levels from installing sound-absorbing material at the operator station is not expected. 6.2 Load-Haul-Dumps (LHDs): A fully enclosed environmental cab can provide 20 dB(A) or more of noise reduction. If a fully enclosed cab is impractical, a partial cab can provide useful protection as long as the openings face away from the primary noise sources. A partial cab with three sides and a top was found to provide more than 10 dB(A) of noise reduction. Both full and partial cabs should have similar results on other underground equipment. When installing a retrofit cab, it is wise to contact the original equipment manufacturer to ensure that the integrity of the falling object protective structure (FOPS) is not compromised. 6.3 Jumbo Drills and Bolters: When applying noise control treatments, care should be taken to use the right product for the job. The 0.5-inch-thick rubber conveyor belt mats used to cover the electric-motor-powered hydraulic pumps on the jumbo drills and bolters were effective at reducing noise because the heavy rubber is a barrier material, which is the correct choice for the application. Rubber is usually not the best material to use for a barrier, but in this case it was effective. On bolter 2, the electric motor and hydraulic pumps were covered with sound-absorbing material. In this instance, the treatment had almost no effect on the noise from the electric motor and hydraulic pumps because sound-absorbing material makes a poor barrier. Sound-absorbing material is most effective when it is used at a reflective surface. The cover should have been constructed using a barrier lined with sound-absorbing material to surround the electric motor and hydraulic pumps. Prior to developing noise controls for a source, the significance of this source should be considered relative to other noise sources on a machine. In this case, the sound level with the electric motor and hydraulics operating was 85 dB(A) whereas noise due to drilling and bolting is about 100 dB(A). In this case, the noise due to the electric motor and hydraulic pumps is insignificant. Windshields on jumbo drills and bolters reduced the sound level at the operator's station during the drilling/bolting cycle up to 3 dB(A). The noise generated from drilling and bolting is relatively high frequency in nature. Therefore, the windshield provides an effective barrier. Gaps between and around sections of the windshield should be sealed for the most effective noise control. In addition, wrapping a windshield around the operator station improves the noise reduction by forcing drilling/bolting noise to travel further around the windshield to get to the operator. In addition, this helps block noise reflected from the rib from reaching the operator. 6.4 Lessons Learned: Through evaluating different noise controls on underground machinery, NIOSH researchers discovered several findings. Both the effective and ineffective treatments rendered valuable information. 1. Although it is tempting to use sound-absorbing materials for noise controls because they are inexpensive and simple to attach to existing surfaces, sound barriers were always more effective in the examples NIOSH studied for this report. 2. Windshields and environmental cabs can be highly effective noise controls, especially for high frequency noise. 3. Plugging gaps in machine panels and windshields with a material that creates an airtight seal can greatly enhance the noise reduction benefits of existing barriers. 4. Gaps in barriers compromise noise control effectiveness. 5. When openings in enclosures are necessary, a partial enclosure can provide some benefit. Enclosures should be lined with an absorptive material thick enough to absorb the dominant sound frequencies. Openings to let air in and out of the enclosure should have lined ducts with multiple bends to absorb sound and to force it to follow a circuitous pathway before exiting the enclosure. In order to reduce noise-induced hearing loss from work-related noise exposure, mine workers, union representatives, mine managers, equipment manufacturers, NIOSH, and MSHA must work in partnership to successfully construct and implement new and better noise controls. To ensure the success of a noise control program, appropriate materials must be applied and the noise sources treated must be significant in terms of the worker's daily noise exposure." - NIOSHTIC-2