Tag Archives: Superstack

Derrick offers higher screening productivity in confined spaces with the SuperStack

Derrick Corporation has introduced its new 8-deck SuperStack® vibratory screening machine, which, the company says, offers two-and-a-half-to-three-times the capacity of its precursor, the 5-deck Stack Sizer®.

With its eight decks operating in parallel, combined with a 30-35% increase in effective screening width per deck, the SuperStack achieves significantly higher production capacity with only a modest increase in footprint, according to Derrick.

While the 5-deck Stack Sizer is equivalent to a 5 m wide by 1.5 m long screen, the 1.42 m wide SuperStack is equivalent to a 11 x 1.5 m screen, the company said, adding that all screen frames are coated with abrasion-resistant urethane for extended service.

More effective use of screen area and increased capacity results from the front-to-back screen tensioning system, which tensions the panel in the direction of flow rather than side to side. In addition to increasing productivity, the tensioning system reduces screen panel changing time by 80-90% compared with side-to-side tensioning, according to Derrick.

Derrick Polyweb® urethane screen panels with 150 or 180 micron slotted openings are available for the SuperStack and an optional repulp spray system introduces free water into replaceable rubber wash troughs to help undersize material pass through screen openings.

Dual oversize launders (one per side) and a single undersize launder eliminate the need for a large hopper, which minimises height requirements. Each feeder additionally has a removable front cover to facilitate maintenance and debris removal, while custom designed inlet pipe configurations are available from Derrick, if needed, to meet equipment layout requirements.

The Flo-Divider™, which equalises flow from the feed source to each deck, meanwhile, is available in a number of discharge outlet configurations from two-way to 16-way.

Dual vibratory motors are positioned directly over the upper screen frame to deliver linear vibratory motion to all eight screen decks, with the motors having an internal oil lubrication system that eliminates the need for a separate lubrication system, while providing long-term maintenance-free operation and low sound production.

Todd Burchett, Vice President – Mining and Industrial Division, Derrick, said the SuperStack is a highly efficient means of achieving major production increases within a comparatively small footprint.

“Consequently, we expect the SuperStack to fill the need for higher productivity in facilities where space is limited.”

Mitch Derrick, Derrick CEO, said the innovative solution offers over twice the capacity of traditional units in a similar footprint, “significantly reducing both the upfront installation costs and ongoing operating and maintenance costs”.

Dan Cook of American Silica, which has already experienced the Superstack, said his company had seen a “vast improvement in quality and efficiency”. He was especially pleased with the ease of changing the SuperStack screen panels, according to Derrick. “The front-to-back tensioning makes screen changes faster than the 5-deck.”

Noting the productivity improvement, Cook said plant capacity had increased by about 20%. “We’ve gone from 700 tons (635 t) per shift to 950 tons per shift! And we believe it can handle more than what it’s rated for. We’re really pleased with the 8-deck!” he concluded.

Earlier this year, Derrick said Metalloinvest was planning to use the new 8-deck SuperStack at the Mikhailovsky mine, in Russia, as part of the company’s project to improve the quality of the operation’s iron ore concentrate.

Vale Canada set for Sudbury emissions cut with Clean AER operation

Vale’s Sudbury, Canada, operations are set for an 85% reduction in sulphur dioxide emissions after the Brazil-based company completed its C$1 billion ($792 million) Clean AER (Atmospheric Emission Reduction) project.

The project is the largest single environmental investment in Sudbury’s history and, on top of the sulphur dioxide emission cut, will also see metal particulate emissions come down 40%, according to Vale.

Work began on the project in 2012 and included the construction of two new converters, a wet gas cleaning plant, a new secondary baghouse and fan building and reconstruction of the smelter converter flues. Due to close coordination between the project and operations, this construction took place safely while the Copper Cliff smelter continued to operate.

Ricus Grimbeek, Chief Operating Officer of Vale’s North Atlantic Base Metals Operations and Asian Refineries, said: “The completion of our Clean AER project is a historic milestone that demonstrates how far we have come as a company in reducing our environmental footprint.”

Emissions are set to come down so significantly with the project that Vale’s Sudbury operations will no longer require its iconic “Superstack”, according to Dave Stefanuto, Vale’s Vice President of North Atlantic Projects.

The Superstack is the tallest chimney in Canada and the Western hemisphere, measuring in at 380 m. It entered full operation in 1972.

Two new 137 m stacks are currently being constructed in the Copper Cliff smelter, which will require far less energy to operate than the Superstack and reduce greenhouse gas emissions from the smelter by some 40%, Vale said. Following construction of the concrete shells, steel liners will be installed in the new stacks in 2019.

In 2020, the Superstack’s steel liner will be removed and the Superstack will be taken out of service and placed on care and maintenance. It is expected that removal of the concrete shell will begin thereafter and continue over several years.

Vale’s operations in Sudbury are home to one of the largest integrated mining complexes in the world with five mines, a mill, a smelter and a nickel refinery.