Safety of Miners in the Opal Fields

Summary

This essay focuses on safety of miners in the opal fields. It looks at the major potential hazards in the opal fields and ways to ensure safety from these hazards. These hazards include explosives, unstable ground, shafts, machinery and dust.

The claim is only as safe as the miners who are working on it. If miners can not follow laws and preventions outlined then the claim will not be as safe as it could be.

Introduction

Opal mining is an exciting but potentially hazardous occupation. A responsible miner should be able to identify and minimise risks. Many people can come onto a claim such as noodlers, miners and tourists. The claim can either be current with people working or it could be old and abandoned. The condition that the claim is left in has a major impact on the safety of any person who walks onto the claim. Specific laws and regulations have been set down by the government, which must be abided by to ensure a minimum safety standard is set. The top five potential hazards are explosives, unstable ground, shafts, machinery and dust.

Content
Claim Preparation

Many risks arise from previously worked areas. Old workings such as drill holes and backfilled or covered shafts, which could be covered by vegetation, are potential risks. Shaft positions should be approximated if mining nearby. As these old shafts can collapse, it is advisable to leave a safe distance between shafts. If work is to be commenced in old shafts a number of checks should be completed. Drives, pillars and levels poor ground should all be checked and noted. Notes may include workings on two levels with the lower level directly beneath the upper. Large un-pillared areas, thin crowned pillars and fretting or cracking of pillars. Lastly cracks in the wall and roof and pillar size should also be checked.

Claim boundaries are also a key point to avoid breaking into other neighbouring shafts.

Explosives

Experience in using and handling explosives can often lead to complacency. Inexperienced people not only can be potentially dangerous to them but can also pose risks with miss fires, unstable walls and fly rock. Licences to purchase, transport, store, handle and use explosives must be acquired and kept up to date. This ensures a minimum standard of safety is achieved.

Not only are licenses important to ensure safety but storage, transport and use of explosives can be more important. Ensuring that all explosive equipment is stored appropriately is a must. Explosives should be stored correctly in a cool, dry place with detonators stored separately from explosive material. Other storage measures which should be met is that the explosive boxes are wood lined and locked. The boxes must be wood lined to ensure no static build up occurs and creates a spark.

The storage areas of diesel and Nitropril should be well separated to ensure if there is a spill that they do not mix.

Many laws are already put in place for the way explosives are transported, prepared and blasted. These laws are put in place for a specific reason which is safety, any deviation from the processes set out could result in a potential injury.

Explosive Fumes

Various gases are generated due to blasting. Gases such as carbon monoxide, nitrogen oxides along and other noxious gases pose a potential health hazard after a blast. The reason these gases are dangerous is because they displace the oxygen available for breathing. For this reason adequate ventilation is required to release these gases before entering the blasted area.

When a blast occurs a blast radius should be put in place to ensure the safety of other miners. In underground mines there is no law but it is recommended that miners do not stay underground. Gases generated from the blast can disperse throughout other shafts and may also cumulate their if there is inadequate airflow, the blast may also cause sections of the roof to collapse. Gases which are dispersed throughout the mine can cumulate in low or high cavities depending on the gas. Carbon Dioxide is heavier than air and can cumulate in low spots and floor cavities. Carbon Monoxide is lighter than air and can cumulate in high spots and roof cavities. Areas of known for having inadequate airflow should be checked after blasting to ensure the gas levels are at a safe level. Fans, blowers and other ventilation systems should be used to extract the noxious gases from the mine. These should be used in preference to natural ventilation as they are much quicker.

Unstable Structures

The geological structures of opal fields vary. There are some structures which can support a wide underground area, yet others are blocky material with faults which makes mining difficult and not recommended. Opal mining in South Australia is quite difficult as the general bearing rock is weathered, brittle and fractured. Each place in SA is different due to the stress distributions and rock types. With all of these factors it is up to the miner to decide weather it is safe to start underground mining in that area.

In certain geological structures cave-ins can occur. A survey of the underground mining area should be done, noting old workings. Whenever underground a miner has to be constantly aware of the conditions especially the roof stability. An unstable roof which could be due to hidden faults could result in a rockfall which could be fatal.

Weather conditions can also affect the wall structure and integrity. Air entering the mine can dry out ground and open up cracks, slides or faults. This drying of material can cause slabs of ground to fall. If a large amount of water gets into the mine the supporting strength of walls and pillars may be reduced. Care should be taken to identify if and fretting has occurred at the base of structures. Any operating shaft should have the entrance to it kept in good condition. Loose rocks, material and tools should all be cleared from the entrance as these can easily be knocked into the shaft. The likes of wind, weathering or even a blast close by could cause material to fall.

For all of these reasons outlined with falling objects it is essential to wear a hard hat at all times. All of these factors can potentially be fatal, but these factors are generally overlooked as miners often become complacent and do not check the stability and strength of walls and roofs very often. These checks should become essential to a miners daily routine.

Shafts

Shafts are the key entry point to the underground sections of the mine. Keeping the shaft in good condition is essential to safety. Support structures at the top of the shaft, such as timbers and pipes, should be kept in good condition. When entering any new shaft weather it is blind or dead it is essential to ventilate the shaft to clear away gases.

Underground areas must have at least two means of exit. This is in case one exit gets blocked for some reason which could be due to a rock fall. Having two exits requires regular maintenance to ensure that both mechanisms, which are subjected to corrosion and weathering, are safe to use.

There is a significant risk of people falling down an open shaft. Not only are tourists at risk but also the miners. Small shafts can catch a person’s leg or ankle and cause injuries whereas larger shafts pose risks of vehicles and people falling in. It is recommended to leave a ring of dirt around the shaft entrance to signify that a shaft is there. When a miner leaves the claim, it is their responsibility to leave the shaft and its surroundings in a safe condition. Manner

Machinery

When operating any machinery either above or below ground a pre-start check should be completed. This is to ensure the machine you are about to operate is in a safe working condition. Items which should be checked are fluid levels, tyre inflation and condition, track tension, gauges, lights, hydraulic rams, lines and buckets, brakes and steering.

Any diesel machinery in operation gives off carbon monoxide, nitrogen oxides and other noxious gases. These gases are similar to blasting gases and can be fatal if inhaled in large concentrations. When in large concentrations these gases can not be seen or smelt. Care should be taken when operating any machinery underground ensuring adequate ventilation.

Dust

A major hazard when working at a mine is dust. Dust can cause or trigger numerous health problems such as skin irritation, allergies and respiratory damage. Generally particles of dust are caught within the nose, throat and bronchial tubes. A small amount of these particles however get into the breathing system, due to their size and shape. It is these particles which cause the most respiratory problems. Dust particles which are of a particular concern are silica. Silica is found predominantly in sandstone host rocks. High exposure to small silica particles can potentially cause a fatal lung disease called silicosis. Although all dust can not be tested for silica it is essential to restrict dust exposure to a minimum.

Ways to control dust include extractors, collection systems and maximum airflow. Wearing a respirator or a dusk mask at the absolute minimum will help prevent the amount of dust that a miner will inhale. Although it is essential that the correct respirator or dust mask is used, as each one is different, depending on what cartridge is installed in the device.

Electrical

Operating machines or tools underground will generally use electricity. It is important to remember that electricity seeks the path of least resistance to earth. Most cases the path of least resistance is the human body as it is 80% water. It is vital that the design and installation of any electrical supply is safe. The miner can not come into contact with any live electrical component.

Personal protective equipment

Personal protective equipment (PPE) will help in protecting a miner from potential hazards. PPE is not a replacement for getting rid of a specific problem. It would be preferable to fit an extraction system for dust rather than wearing a dust mask.

A number of items should be worn when working in a mining area such as hard hats, footwear, breathing, hearing and eye protection. Hard hats can be uncomfortable, fall off and restrict clearance in small spaces, but these inconveniences save lives. Footwear suitable for miners are steel capped boots. They provide much more support for ankles and grip when walking on loose and rugged surfaces. The steel cap provides protection for your toes if something drops or falls onto your feet. Breathing protection general comes from dust masks either rubber of paper. Both are designed to sit on a clean shaven face. If the miner has a bear or stubble the effectiveness of these masks is reduced. Hearing protection generally comes in two forms which are ear plugs and ear muffs. Ear protection only cuts out part of the noise, usually around 20db(A). Since only part of the noise is cut out it is important to ensure that the miner realises that higher levels of ear protection is required when working next to excessively noisy machines such as jack hammers. In general eye protection should be worn at all times. There is a constant risk of particles of some nature being airborne and possibly entering the eye. Damage to the eye may be something small like a scratch to actually losing an eye.

Discussion

These rules and advised safety precautions to be taken are put in place for a reason. It is solely to help protect the individual from getting injured or killed. But miners in the opal fields generally have the she’ll be right attitude. A large amount of preventions can be put in place to help ensure safety but if the miner does not follow them these are next to useless. They may think only a short amount of exposure to dust is fine, but if they continue to have exposure to dust containing silica they could cause the onset of silicosis. Not only can you do internal damage through various noxious gases and dusts, but a lot of damage can be done to the body itself. Cuts, sprains and broken bones are a number of things which can occur depending on how safe, cautious and or ignorant the miner is.

Conclusions

The top five potential hazards in opal field mining are explosives, unstable ground, shafts, machinery and dust. All of these potential hazards have laws, regulations and precautions put in place to ensure a minimum standard of safety. This minimum standard of safety is only reached if the person who enters the claim follows the guidelines. The bottom line being that safety in the opal fields comes down to each individual that enters the claim. If the miner is ignorant, complacent or plain lazy the safety of not only themselves but for others working with them could be at risk. It is the miner’s responsibility to ensure that not only are they safe but also fellow co-workers.