Northern Life, Greater Sudbury’s community newspaper, gave Republic of Mining.com permission to post Bill Bradley’s article. www.northernlife.ca
Designing Out Trouble
(Final instalment of a four-part series) Sudbury Soils Study
Both Vale Inco and Xstrata have committed to being part of the solution and not the problem. They said that in a joint news release on May 13 after the release of the Sudbury Soil Study Human Risk Assessment.
The first necessity is better information about what emissions, such as dust, are being released.
Before the Sudbury Soils Study, the Ontario Ministry of Environment (MOE) conducted monitoring of air emissions at Nickel Street in Copper Cliff and Lisgar Street in Sudbury. In 2003, both companies agreed to fund an expanded air monitoring program, including samples of particulate matter (PM10) which is thought to be more relevant for inhalation into a persons’ lungs. In 10 locations, 20 monitors were set up. That data was used in the Sudbury Soil Study.
Two were placed close to Vale Inco’s Copper Cliff Smelter (Nickel Street in Copper Cliff and Traverse Street) in the western part of the central core. Three new stations were added in response to a SARA Group recommendation-Spruce Street, Delki Dozzi Park and at the Copper Cliff Creek station in Copper Cliff. A sixth particulate station was established in the Little Italy area of Copper Cliff in September 2007 on Venice Street.
“Information gathered from these particulate monitoring stations will allow the company to accurately measure its performance in implementing dust control measures and reducing ambient levels of nickel in PM10 dusts,” states the Risk Management Report by Vale Inco and Xstrata, as part of the release by the Sudbury Soil Study.
In addition, in May 2007, Vale Inco initiated mobile monitoring. Monitors were mounted to a truck and trailer, allowing for more flexibility of assessing dust.
Baghouse inspection was a key activity to be completed. Baghouses filter dust primarily from drying, crushing and conveying activities using fabric filter bags.
The AB Baghouse in Matte Separation was replaced with a more efficient unit. Accompanying this were modifications to conveying systems in the Fluid Bed Roaster area to reduce the amount of airborne dust generation. Real time dust monitors were installed in some baghouses and the signals routed to the control room for instant viewing by operators.
Xstrata Nickel uses an Environmental Management System (EMS). Between 2001 and 2004 an inventory was conducted of significant sources of particulates including stacks, vents and exhausts from various plant facilities, material handling activities, paved and unpaved roads, and outside sources from erosion.
In the Falconbridge area, total suspended particulate and PM10 (fine particulates) are monitored at stations on Edison Road and at the Number 4 Well Pumphouse. All data collected is shared with MOE.
Baghouse inspection was a key activity to be completed.
Old baghouses are being replaced and better detection systems for breaks are being installed. Electrostatic precipitators are another source of dust.
Electrostatic precipitators are another source of dust. They use electrically charged plates and wires to remove dust from high volume gases such as those from bulk converting, copper smelting and refining and fluid bed roasting processes. Captured dust is recycled back into the process.
For converters, studies are underway for improving dust collection in No. 7 and No. 8 converters. A plan is underway to collect process and converter aisle emissions by developing a large baghouse for the entire converter aisle emissions.
Outside sources can also be significant. Roads are being paved and a new road sweeper purchased. New dust suppressants on roadways are being tested. To further control dust, 50 hectares of reclamation per year is being undertaken with 60,000 to 100,000 trees planted.