A major concern in producing aggregates is the respiration of airborne dust – specifically crystalline silica dust – generated by operations including crushing and screening, conveyor movement, transportation, transfer points, stockpiles, and storage. If enough respirable silica dust is aspirated, it can develop into silicosis, a disabling and irreversible lung disease that can even become fatal.
In addition to posing health risks, fugitive aggregate dust can drift farther into the facility, where it can:
- reduce visibility
- create costly extra housekeeping and maintenance
- cause premature wear on equipment such as pulleys, idlers, motors, and portable conveyors
If left without control methods for too long, the airborne dust also can move into the wider community and endanger it as well. Fugitive dusting can be greatly reduced and controlled with a properly designed and applied dust suppression system.
Dust Control Options in the Aggregate Industry
Water Alone is NOT Your Friend
Dust-reduction methods have included using sprinklers or hoses to weight dust particles with water before they can linger and travel. Over time, however, this practice has often proven to create new issues while only temporarily addressing a dust problem. Aside from requiring extra labor hours, it can result in excess surface saturation and runoff as well.
Properties of water droplets can counteract operators’ dust control efforts as well. Droplets from hoses, sprinklers, and faucets are typically too large, hard, and heavy to properly subdue aggregate dust. Heavy water droplets remain in the air only shortly, limiting the amount of dust particles they can capture. Water’s high surface tension likewise restricts their capacity in trapping fugitive dust.
When in motion, water’s large droplets create a slipstream air current that dust particles can ride around them. The droplets and particles then cannot make contact, allowing dust to escape. Standard droplets’ limitations compound even more when a facility operates in arid conditions where water can evaporate more quickly. Because of their properties, water droplets alone will rarely achieve consistent dust control and prevention.
Dust Suppression for Aggregates
Properly controlling fugitive dust requires water droplets with a size and surface tension that better matches the material being treated. Dust suppression is the engaging of dust particles with traits more certain to subdue them. It achieves this with an eco-friendly, biodegradable dust suppressant with inherent benefits that also help to lower water consumption.
The dust suppression chemical agent breaks the surface tension of the water and particle, thus clinging to the dust particles, increasing their size and weight, and forcing them to fall from the air. When combined with water, the dust suppressant also forms a microscopic film that strengthens the bond between the material surface and dust particles to further restrict their escape. Dust suppression chemicals can help prevent ground-level dust from becoming airborne as well.
A focused and strategic dust suppression system can have a major impact on dust control throughout processes at an aggregate facility, including:
- stockpiles
- stackouts
- reclaimers
- transloading hoppers
- feeders
- pugmills
- crushers
- transfer points
- ship-loaders
- haul roads
- rail & truck dumps
- warehouses
MiniPak – Portable, Power-Free Dust Suppression
Aggregate facilities that contend with dust control in multiple areas may find they require greater ease and versatility in how and where they can apply a solution.
In such instances, dust suppression methods can include a portable powerless system for use at fixed locations. Easily installed by a single-person manual operation, the MiniPak is a power-free, self-contained enclosure that allows personnel to apply dust suppression chemicals specifically engineered to be non-toxic, non-explosive, and biodegradable anywhere from haul roads to the load zone.
The system becomes a flexible asset in providing dust control with less equipment at fewer application points. It also solves potential problems that involve space and electrical power constraints. At some aggregate facilities, larger, fixed systems may not be feasible because of these constraints.
Aggregate Industry Literature
| Aggregate Industry - Brochure | Download |
| Silica Dust Control Solutions - Brochure | Download |
| Soluciones para el Control del Polvo Sílice - Folleto | Download |
| "Silica Dust MiniPak Solution" - Success Story | Download |
| QuickSkirt (for Stacking Conveyors) - Flyer | Download |
Posted in Dust Control, and Silica Dust