This is a follow up article of the first article we penned on drill and blast dust control solutions – an industry guide. GRT further evaluates how drill and blast dust is generated, the chemistry and particle size of drill and blast dust, and best industry practice for binding drill and blast dust at its source. We start off by asking the most pertinent question which will motivate for more discussion of the critical aspects to unpack drill and blast dust control – What is drill and blast dust control? It is the use of chemical dust palliatives to control dust at its source and prevent exposure to inhalable and respirable fugitive dust particles which can lead to lung diseases such as silicosis, coal mine workers pneumoconiosis and lung cancer. Dust kills and no amount of exposure is okay and elimination of dust at its source should be a priority. Prevention is the best option for there is no cure to lung diseases that result from exposure to dust particles from drill and blast operations. Drilling and blasting are very challenging activities with many hazards. In mining and quarrying the challenges associated with rugged highwalls and bad fragments should never distract the importance of drill and blast dust control for drill cuttings, drill stockpiles and fugitive dust particles. It’s a stark contrast between productivity and saving lives with the former often prioritised over human health of workers and local communities. Perhaps the more discussions openly tackle the issues with dust exposure to workers and communities the more transparency will ensue in the interest of saving lives. Preventing dust related lung diseases is a sole mandate driving the GRT team to keep providing feasible and effective solutions for drill and blast dust control.
How is drill and blast dust generated?
How drill and blast dust is generated is a question that we will answer through describing drilling and blasting techniques. So, in essence defining drilling and blasting should precede the dust generation. Drilling and blasting are techniques used in quarrying, mining and tunnelling to derive economic value from rock masses through (1) creating a blast pattern (2) blast hole drilling into the rock surface (3) charging the blast hole with explosives (4) detonating them in a planned sequence to achieve different rock fragments. More information about drilling and blasting techniques, risks and hazards and a summary of respirable dust as a hazard are given in a recent industry article we published. Dust is generated from fragmentation of rocks in both drilling and blasting. As the cycle of retrieving rock materials continues dust also is generated from crushing and separation of the burden into smaller fragments. Transportation of the rock material also generates a lot of dust particles with vehicular movement contributing to the dust generation as well. It is very important to consider the drill to blast rock production cycle from a dust generation perspective.
Chemistry and particle size of drill and blast dust.
Chemical surfactants in combination with water can be used to suppress dust at its source. Given the particle sizes invisible to the naked eye – dust can be an invisible killer. The binding of dust particles follows a physico-chemical mechanism involving particle size distribution and the interaction between the attraction and repulsion based on the chemical nature of dust particles. Chemical surfactants superactivate water, enhancing its ability to bind to blast pattern dust and this increases the ability of water to attract fugitive dust particles and keep them bound to the ground. The silica that is harmful to humans is respirable crystalline silica.
Are environmental regulations, health and safety concerns or potential profit loss a concern right now?
Let’s break that down –
- respirable means it has to be in particles small enough to get past the upper and mid airways and into the deep portions of the lungs. Everything else will be captured and expelled in mucus or by coughing and sneezing.
- it has to be crystalline dust – the particles, although microscopic, have to have a defined crystalline shape with sharp surfaces. This is what starts causing problems in the lungs. The sharp crystals embed in the tissue of the air sacs and result in scarring. When the scarring gets severe enough, the tissue loses its ability to expand and contract. When enough tissue is damaged, the lungs lose capacity to process air. And to add insult to injury, the damage can lead to lung cancer which can result in death.
There is no cure to silicosis – the ‘sidelined yet loud’ health crisis
Most health issues related to mining occur due to some form of exposure. Notoriously, it is an occupational hazard among industries finely processing rock in the case of drilling and blasting. It’s the silica generated in these activities that can get in the air, and if inhaled, cause silicosis, a type of scarring in the lungs. Inhaling silica dust can be very harmful, particularly in high levels, which depend upon the degree of exposure. Silica dust inhalation can be caused by multiple exposures, mostly from drill cuttings from drill and blast activities. The 3 common types of silicosis are:
- Chronic silicosis — exposure to silica dust for more than 10 years
- Accelerated silicosis — exposure to silica dust for 3-10 years
- Acute silicosis — develops within weeks or months of exposure to silica dust
All 3 types affect you in the same way. The difference is how long it takes for problems to develop. Despite the source, all forms are really bad for one’s lungs, and can cause the symptoms of silicosis. The main symptoms of silicosis are shortness of breath, chest pain, cough and tiredness. But in the early stages of silicosis, there may be no symptoms. The symptoms become severe as the condition gets worse. Eventually, simple activities such as walking or climbing stairs difficult. Further effects include trouble sleeping and eating properly. Drill and blast dust kills! The risk of death increases with other health comorbidities one could have. So what is the industry best practice that GRT is offering?
Best industry practice from GRT
Mining, quarrying, exploration drilling and bore holes are just some of the few key industries benefiting considerably from GRT: 12X. which provides dynamic dust management and 12 times more effective at dust capture than water alone, GRT: 12X is the safest way to alter the profile of water so that it instantly targets the dust that causes black lung and silicosis, to prevent it from becoming an airborne hazard. Our most advanced product yet, GRT: 12X will revolutionise the way you manage dust. Dosed into the drill rigs water tank at ratios of 1:1000 to 1:2000 (soil dependent) GRT: 12X penetrates the material surfaces and intercepts airborne particles immobilising fugitive dust. It also helps to create a more stable hole, reducing the risk and subsequent costs of hole collapse. Importantly, the solution does not impact ore properties and drill and blast activities.
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REFERENCES
Petrosyan, M.I. 1994. Rock Breakage By Blasting. Taylor & Francis Group.
