Tag Archives: dust monitoring

Why Dust in Monitored

Why Dust is Monitored

Industrial dust can explode.  These occur when a large build up of combustible dust is dispersed into the air and then explode if provided with an ignition source.  Immense damage and loss of life can follow. (See video – https://www.csb.gov/csb-releases-new-safety-video-inferno-dust-explosion-at-imperial-sugar/)

Other dangers that industrial dust pose are lung diseases caused by the inhalation and retention of dust in the lungs. Coal miners especially are exposed to many kinds of dusts including silica. Tiny particles of coal dust are retained in the alveoli – they are surrounded by macrophages but, eventually, the system is overwhelmed and an immune response follows.

It is impossible to prevent all industrial dust diseases but they can be reduced by various safety precautions, such as adequate ventilation, keeping down dust levels and wearing of facemasks.

An extremely important factor in prevention of dust related problems is the monitoring of dust using specially engineered equipment. Dust monitoring equipment assist industry and agriculture in detecting harmful levels of toxic dust which in turn allows the problem to be engineered away.

Dust not only causes health and safety problems but can also cost industry money in terms of equipment maintenance and production. See the extract below from the website http://www.dust-monitoring-equipment.com/services/dustdesign.htm  : “We have successfully removed fish scales from marine diamond deposits with specialized dust control equipment.   The fish scales were not actually a dust problem but they did interfere with the optics used to separate diamonds. This is similar to the problem where we had to de-fluff diamond concentrates from underground mining operations, where a slurry explosive is pre-packed in plastic bags. The slivers of plastic fluoresced in the same way that diamonds fluoresce and needed to be removed from the process.”

In general finer suspended dust remains airborne almost indefinitely due to air currents and thermal activities on any given day, even if there is no wind at all. The unit that we use to capture this dust is the DustWatch, designed and patented in South Africa by Gerry Kuhn Environmental and Hygiene Engineering.

The use of fall-out monitoring yields a large amount of information, allowing a far greater and effective study to be undertaken than any other single sampling method. If used in combination with PM10 or total particulate dust sampling, results can be very conclusive.

Why Dust in Monitored - Dust Bucket - Fallout dust monitoring - DustWatch

Why dust is monitored

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

Fugitive dust management

A few interesting articles from Mining Weekly (please follow the links to the original articles) regarding dust and waste management.  Enjoy the read!

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Comprehensive package facilitates fugitive dust management – Mining Weekly
BY: TASNEEM BULBULIA 18th May 2018

“Fugitive dust emissions pose risks to mining companies, surrounding communities and the receiving environment, and require proper management to mitigate their effects, and environmental management company I-CAT is well poised to do so through its comprehensive solution offering.

I-CAT Environmental Management and Consulting divisional manager Leon Janse van Rensburg says fugitive dust emissions are inherently part of the mining industry, owing to the nature of mining activities, such as blasting, minerals processing activities and fugitive dust emissions emanating from haulage roads. Emissions are especially prevalent in opencast mining and associated activities, the processing of raw mine materials using crushing and screening plants, and on waste rock dumps or mine tailings through windblown activities.

While not the biggest contributor, dust emissions contribute to the overall ambient PM10 (the fraction of particulates with a diameter of 10 μm or smaller) concentration in the atmosphere. Therefore, it is still a problem that should be properly managed, Janse van Rensburg emphasises.

In terms of the environmental impact of dust emissions, dust particles can become entrained in the atmosphere, resulting in the quality of ambient air decreasing and, in some cases, cause visual impairment near the source of emission. Further, surface waterbodies can become contaminated by dust particles settling on the surface, while the biodiversity of fauna and flora in areas surrounding mining activities can also be negatively affected by dust fallout.

Janse van Rensburg highlights that surrounding communities can be affected in two ways: socioeconomically, dust contributes to the devaluation of property in a mine’s surrounding area; in terms of health, inhaling dust particles over time can lead to a range of negative health effects.

For mining companies, the impact manifests financially, such as increased maintenance for mining equipment; and operationally, such as an increase in downtime often because of visual impairment when the dust emissions become too excessive.

From a health and safety perspective, mineworkers can inhale dust emissions, resulting in a range of occupational illnesses and diseases, which could further result in increased liability to mining companies.

Comprehensive Solution

Janse van Rensburg indicates that I-CAT’s dust management package constitutes the actual planning and implementation of dust management measures and technologies for mines.

In terms of operational control measures, this can include something as simple as implementing speed limits on the roads, and avoiding the excessive clearing of natural vegetation on mining sites. This mitigates the prevalence of areas that are void of vegetation, as these areas contribute to excessive dust emissions as particles are mechanically entrained in the atmosphere through windblown activities.

I-CAT aims to deliver a customised solution geared specifically for the challenges of clients. The type of solution is usually dictated by the source of the dust, which can either originate from a point or non-point source. Point source dust emissions are created from a static point, such as dust emissions created from a processing crusher, while a non-point source is variable, such as dust emission originating from haulage roads.

Technologies for point source systems include misting systems, which can contribute towards restricting particles from becoming airborne by addressing the problem at the source. Essentially, a misting system encourages the binding of water molecules with dust particles, resulting in the formed particle being heavier and drawn down to the surface under gravity.

In terms of technologies for non-point systems, water can be used in conjunction with road dust palliatives for primary and secondary roads. Dust palliatives aim to bind soil particles together over a longer period while using less water, as the application frequency of using dust palliatives in an aqueous solution is far less than the application of a water-only solution, Janse van Rensburg indicates.

He emphasises that using water only is not a feasible solution for dust management and suppression, owing to the scarcity of this resource in the country. Water also tends to evaporate quickly, which, in turn, allows for small particles to become entrained in the atmosphere in a short time period.

Other measures entail enclosing conveyor areas of mining plants’ offloading points and associated extraction, and collecting the dust particles into dust-filtering and storage infrastructure.

I-CAT has been designing and supplying these solutions and technologies since 2009, with numerous clients indicating that implementing the company’s technologies has had a positive effect on mitigating the negative effects of dust emission at mines, says Janse van Rensburg.””

For more please follow the link above………

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Sustainable solutions possible for AMD treatment – Mining Weekly 
BY: ERIN STEENHOFF-SNETHLAGE

“Multidisciplinary engineering consultancy WSP Africa states that, while acid mine drainage (AMD) decants in the Witwatersrand goldfields and surrounds should be dealt with urgently, there is no company large enough to start a large-scale water rehabilitation programme.

“The Witwatersrand goldfields is the area most threatened by AMD. After 120 years of mining in the area, the Western basin started to decant AMD in 2002. There are no large companies currently mining in this area, so no one [can] initiate a project of the scale needed to prevent the decant,” says WSP Environment and Energy Africa senior associate Karen King.

The onus to develop, own and operate AMD treatment facilities falls on the mines, with “mine closure plans supposed to adequately account for AMD prevention solutions, new mines should not be allowed to open without such plans”, she points out.

However, the responsibility also lies with government to oversee and govern mine closure plans, King adds. “[Some] of the country’s environmental policies, centred on mining and polluted water, are far better today than what they were in the past, but they need to be more strictly enforced,” King puts forward.

To date, AMD has caused considerable damage to the Wonderfonteinspruit, Tweelopiespruit, the Tudor dam and Robinson lake areas, King emphasises. The flooding of the Central basin in the Witwatersrand area has also been linked to seismic activity.

There is no short-term solution to the AMD issue, as the “effects of AMD can never be entirely reversed”, King states. Considering the existing pollution, the AMD needs to be pumped out of the mining areas and treated. This exercise is often started but not continued, as it is an expense which could bankrupt some mines, she reiterates. Older AMD-generating mines have been closed for many years, with companies unable to afford treatment and rehabilitation programmes.

Sustainable Solutions

King believes that there are sustainable solutions that can be used to treat AMD and help restore the natural environment.

Treatment will depend on the extent, volume and the make-up of the AMD, as well as the geographical area that it affects. Solutions include the diversion of clean surface water from sources of pollution, and the prevention of seepage and groundwater infiltration into affected sites. The placement of acid- generating water also needs to be controlled.

Flooding of potential AMD-generating areas before oxidation can occur is another option, as is the development of the Western Utilities Corporation mine water reclamation project. The project entails a plan to pump the water to a central treatment plant where it can be treated and sold to water utility Rand Water at a profit, but is being received with mixed enthusiasm, claims King. “There needs to be greater market understanding and recognition that polluted water can be a resource – and not a liability – if it is appropriately treated.”

Further, King points out that some considerations need to be taken into account when building an AMD treatment facility. The most important consideration is the standard – for potable, industrial or agricultural use – to which the water will be treated, as this will impact on the design and construction costs of the facility.

The potential AMD decant volumes, AMD chemistry and pretreatment methods also need to be considered. Thereafter, the best methodology must be selected to treat the specific type/s of AMD, King illustrates. Financing, maintenance and personnel training are also important factors to consider.

These factors can also be challenges because the lack of properly managing them could lead to the failure of the AMD treatment plan, she adds. For example, poor maintenance could lead to mechanical failures in machinery, as the aeration equipment can become clogged when the calcium sulfate levels are too high.

Further, an estimated 1.6-million people live in informal settlements next to mine waste residue deposits in South Africa, the majority of which are radioactive, King says, pointing out that long-term exposure to AMD-polluted drinking water and mine-residue deposits can lead to cancer, decreased cognitive function and mental retardation in fetuses.

“AMD needs to be addressed adequately and urgently,” King concludes.”

Why monitor dust in the workplace?

Dust in the workplace

Today we have posted a couple of articles about dust in the workplace and an interesting dust control method used by the US Military………… enjoy the read!

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“Why monitor dust in the workplace? By: Josh Thomas (Source – Environmental Expert)
Courtesy of Ashtead Technology Ltd

Almost any place of employment can present a potential threat to health and safety from airborne particulates and aerosols. It is important to note, however, that dust hazards are not necessarily visible to the human eye and that the finest particles can represent the greatest threat because of their ability to travel deepest into the lungs. Effective monitoring is therefore key to the implementation of an effective risk management strategy.

There are two major reasons for monitoring dust in the workplace; to enable air quality management, and for regulatory compliance. The immediate effects of dust can be irritation to eyes, headaches, fatigue, coughing and sneezing. As such, poor indoor air quality can lower employee performance and cause increased absenteeism through sickness. In addition, particulates are known to create long-term deleterious effects, contributing to serious illnesses. In combination with outdoor exposure (to pollution form vehicles for example), the Government has estimated that 29,000 premature deaths occur in the UK every year as a result of particle pollution. This means that, particularly in urban areas, natural ventilation may not necessarily improve indoor air quality.

Employers are responsible for ensuring that staff and visitors are not exposed to poor air quality in the workplace, so it is necessary to conduct monitoring. Accurate and effective monitoring data can be used to check exposure levels and to help identify safe working practices.

Monitoring also helps to demonstrate compliance with relevant regulations. COSHH is the law that requires employers to control substances that are hazardous to health. According to the Health & Safety Executive (HSE), employers can prevent or reduce workers’ exposure to hazardous substances by finding out what the health hazards are; by deciding how to prevent harm to health; by providing effective control measures; by providing information and training; by providing monitoring and health surveillance, and by planning for emergencies.

In order to evaluate workplace safety, monitoring data is compared with Workplace Exposure levels (WELs) which prescribe the maximum exposure level to a hazardous substance over a set period of time. Failure to comply with COSHH and WELs can result in financial penalties, prosecutions and civil claims.

Indoor air quality is affected by both internal and external factors. Air pollution may arise from external sources such as neighbouring factories, building and development activities, or from vehicles – especially those with diesel engines. Internally, air quality is affected by working practices and business processes. For example, dust may arise from raw materials such as powders, or it may be produced by processes that generate particulates; including dust, mist, aerosols and smoke. In all cases, internal and external, it is important to identify both the source and the seriousness of the problem, so that appropriate and effective mitigation measures can be implemented. These might include, for example, ventilation, process dust prevention, the management of shift patterns, personal protection equipment (PPE) and alarm systems.

Regulatory requirements to monitor

Under the Workplace (Health Safety and Welfare) Regulations 1992, employers have a legal duty to ensure, so far as is reasonably practicable, the health, safety and welfare of employees. Furthermore, the Management of Health and Safety at Work Regulations 1999 require employers to assess and control risks to protect their employees. A key element of this is the requirement to comply with the COSHH Regulations. The HSE says that exposure measurement is required:

  • For COSHH assessment, to help select the right controls
    Where there is a serious risk to health from inhalation
    To check that exposure limits are not exceeded
    To check the performance of exposure controls
    To help select the right respiratory protection equipment
    To check exposure following a change in a process
    To show any need for health surveillance; or
    When an inspector issues an ‘Improvement Notice’ requiring monitoring

The COSSH Regulations include dust, mist, vapour, fumes and chemicals, but they do not cover Lead or Asbestos. Specific requirements exist for certain industries such as construction. Generally, WELs relate to particulate diameter because the health effects of particulates are heavily influenced by their size.

Inhalable dust is that which enters the nose or mouth during breathing and is available for deposition in the respiratory tract. It includes particles with a width between 2.5 and 10 microns (PM2.5 – PM10), and the WEL for this fraction is 10 mg/m3 as an 8-hour Time Weighted Average (TWA).

Respirable dust is the fraction that penetrates deep into the gas exchange region of the
lungs. It includes particles with a width between 1 and 2.5 microns (PM1– PM2.5), and the WEL for this fraction is 4 mg/m3 as an 8-hour TWA. Lower specific WELs exist for particulates that present a greater threat to health. For example, Silica dusts have a WEL of just 0.1 mg/m3 respirable dust as an 8-hour TWA.

The costs of non-compliance

In addition to the enormous numbers of premature deaths that result from exposure to outdoor air pollution, there are also numerous well-documented instances demonstrating the harm caused by exposure to indoor pollution from dust, smoke, aerosols and vapour. For example, a 46-year-old cook developed breathing problems after working with flour in a school kitchen with poor ventilation. Her breathing problems became so severe that she could hardly walk and had to sleep sitting up. She became severely asthmatic and had to retire early on health grounds. With the support of her Union she made a compensation claim on the basis that decent working conditions were not provided, and the council admitted that it had not taken sufficient action despite repeated complaints. Consequently, the courts awarded the cook £200,000 in damages.

In another example, between 1995 and 2004, a solderer was exposed to rosin based solder fumes and suffered health deterioration and breathing problems including asthma. An investigation conducted by the HSE found that the company did not have adequate control measures in place and failed to install fume extraction equipment. Furthermore, the company did not employ rosin-free solder until December 2003, despite an assessment having identified the need in 1999. The company was subsequently fined £100,000 with £30,000 costs, a punishment which attracted both local and national media attention.

Monitoring dust

A wide variety of methods exist for the measurement of dust, and the choice of equipment is dictated by the application. For example, it is obviously important to employ a technology that is able to measure the particulates that will be present. In addition, it will be necessary to determine whether monitoring should be continuous, at a single point, or whether portable instruments are necessary to check multiple locations. Monitoring might be conducted in a work space, or personal sampling might be undertaken in order to assess the exposure of an individual over an entire shift.

Personal Sampling Pumps represent the preferred method for workplace exposure monitoring where it is necessary to demonstrate regulatory compliance or where legal dispute is a possibility. An HSE document (MDHS 14/4) provides workplace exposure monitoring guidance for collecting respirable, thoracic and inhalable aerosol fractions. The samples collected by this process are analysed in a laboratory, which means that chemical analysis is also possible. However, the sampling method incurs a delay and incurs extra cost.

In response to the wide variety of applications and monitoring requirements, Ashtead Technology stocks a comprehensive range of monitors for both sale and rental, providing customers with complete financial and technical flexibility. As a TSI Gold Partner, Ashtead Technology provides a comprehensive range of maintenance and calibration services; helping customers to ensure that their monitoring equipment remains in optimal condition. Ashtead’s fleet of rental equipment includes large numbers of the latest TSI instruments, supported by the highest levels of service and technical assistance. Employing advanced light-scattering laser photometers, the TSI products are supplied with a calibration certificate and provide real-time, direct-reading aerosol monitoring and analysis of different particulate fractions in workplace, cleanroom, HVAC, fugitive emissions and environmental monitoring applications.

The TSI range of dust monitors is continually being developed to bring new levels of functionality to the market. For example, the new lightweight AM520 Personal Dust Monitor is able to measure and log PM10, Respirable (PM4), PM5 (China Respirable), PM2.5, PM1 or 0.8μm Diesel Particulate Matter (DPM), providing real-time audible and visual alarms, and running from a rechargeable battery for up to 20 hours. For outdoor applications, the MCERTS approved Environmental DustTrak is web-enabled, providing a quick and easy dust monitoring solution for applications such as building and development projects.”

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“US Military’s First Choice for Dust Control Solutions – Rhino Snot (Envirotac II)  (Source – Environmental Expert)

Home soil or foreign, whenever the US Military is in need of a dust control job, they call EP&A Envirotac Inc. without a second thought. The US Military first came to know about Envirotac’s dust control products during its Afghanistan mission in 2002, where it used Envirotac II polymer for helicopter landing site and airfields in the Camp Rhino. This is also where Envirotac II received its shiny moniker – Rhino Snot.

Again in 2008, the military used it in Iraq, when the powder-fine dust at the site of Combat Outpost Rawah made helicopter landing extremely difficult. And the best part of working with Envirotac polymers is that they are easy to apply, and make the surface ready for the desired purpose within 24-48 hours.

Besides military usage, Envirotac line of dust control products has many applications in numerous industries, such as road construction, mine tailing, oil pads, parking lots, and so on.”

Farming - dust in the workplace

“Dangers of Dust in the Workplace (Source – Workplace Safety Advice)  By Jeff Durham

Excessive dust in the workplace can be highly dangerous on a number of levels. Firstly, although it’s rare, a cloud of concentrated dust is potentially combustible and can, therefore, cause explosions so it’s important that companies keep their working environments as relatively dust-free as they can to avoid such potential catastrophes. However, the most common problem associated with dust in the workplace arises from dust-related illnesses which have been found to be one of the major killers in the UK when it comes to occupational health.

Common Environments For Contracting Dust Related Illnesses
All workplaces need to carry out cleaning duties and pay particular regard to hygiene issues and, for the most part, in places such as an office for example, dust should not present too much of a problem. However, there are many industries which need to be especially vigilant. Here is a list of some of the more common working environments where excess dust can create a real problem.

  • Mines and quarries – dust from coal, flint and silica
    Construction sites – dust from cement and asbestos
    Farming and Agriculture – dust from grain
    Carpentry and Joinery – dust from wood
    Bakeries and mills – dust from flour
    Textiles – dust from materials like leather
    Dust Related Illnesses

Workers can suffer from a variety of illnesses and medical conditions as a result of working in dust-filled environments. Depending on the nature of the work, some of these ailments can become more serious than others. The range of dust related illnesses and conditions encompass eye and nose damage, rashes and other skin conditions, asthma, silicosis, asbestosis, mesothelioma and lung cancer related to asbestos. Pneumoconiosis, which is the name given to diseases such as those caused by the likes of asbestosis and silicosis, is a broad term which describes any condition which affects the lungs causing inflammation or scarring of the lung tissue. One of the major worries is that it can often take several decades for a person to develop any symptoms of pneumoconiosis which can manifest itself in things like excess coughing, breathing difficulties and even weight loss.

Prevention and Reducing the Risks
There are a number of government legislations which incorporate provisions which are aimed at minimising the risk from dust. These include the Factories Act 1961, the Health and Safety at Work Act 1974 and the Control of Substances Hazardous to Health Regulations 1988. There are also other regulations in place specific to certain industries, the Coal Mines (Respirable Dust) Regulations 1975, being a prime example.
From an employer’s perspective, they need to do all they can to eliminate or, at least, disperse the dust. An exhaust ventilation system will remove the dust from a particular site whilst a dilution ventilation system helps to disperse dust evenly throughout a particular area as opposed to allowing it to build up into a concentrated mass within one specific spot. Where dust has a fundamental presence within a particular occupation, workers need to be provided with the correct protective clothing and with breathing respirators if need be. These are much better than dust masks which have often been proved to be relatively ineffective. Employers should also ensure that workers undergo regular health checks which might pinpoint any early signs of illness.”

For the complete article, please follow the above link.

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Have a great day! Chris

Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

Overburden Blast – Blasting During Low Wind Conditions

Overburden Blast – Blasting During Low Wind Conditions

Wind Speed during a blast will significantly increase the movement of the the dust particles below a D50 of 30 Micron. Other factors will be the temperature and the humidity during the blast so time of day for the blasting is also an important variable to consider.