Mines benefit from corrosion resistant slurry valves

7th August 2015

Conventional valves seldom produce satisfactory results when applied in abrasive and corrosive slurries, says Weir Minerals Africa valves product manager Kobus Steyn.

He explains that this is because conventional valves are generally designed for liquid service, noting that typical problems associated with the use of these valves in slurry applications include rapid wear of valve seats and liners, sticking and leakage.

Steyn says Weir Minerals Africa’s Isogate slurry valves provide a cost-effective solution for on/off throttling and reverse flow controlling of media in processes that involve abrasive or corrosive materials. These range from sand and gravel processing to dredging, as well as use in coal-fired power plants, pulp and paper mills and shot and sand blasting equipment manufacturing.

He adds that Isogate slurry valves are successful in diverse applications because they are easy to maintain and feature low total cost of ownership as the main design criteria.

“Valves form an integral part of Weir Minerals Africa’s total solutions package for the mining and minerals processing and general industrial sectors. Isogate slurry valves operate in some of the harshest and most demanding environments globally,” says Steyn.

He adds that Isogate slurry valves are currently used in applications such as base metals (copper, nickel and iron) to precious metals and gems (gold, silver, platinum and diamonds) and industrial minerals (phosphates, talc, kaolin, silica and clays).

Isogate slurry valves can operate under wide pressure and tem- perature ranges, while sleeves are available in a variety of materials, such as natural rubber, nitrile and neoprene, says Steyn.

“In addition, a unique feature of the valves is that Weir Minerals Africa can also offer its proprietary abrasion-resistant Linatex premium natural rubber liners.”

Product Line
Isogate mechanical pinch valves use a flexible rubber-lined pinch sleeve that is collapsed between two mechanical bars for accurate modulating control, positive closure and drip-tight shut-off. The inside diameter of the pinch sleeve is full-line size for maximum throughput and minimum pressure drop.

The Isogate pneumatic pinch valves are pneumatic or hydraulic actuated, enclosed body pinch valves ideal for remote operations as they use typical plant air and do not require auxiliary cylinder operators.

The valves use flexible rubber-lined pinch sleeves and pinch liners enclosed in robust cast metal bodies that collapse when plant air or hydraulic pressure is applied.

Meanwhile, Isogate heavy-duty slurry knife gate valves combine a low maintenance design with a range of materials for diverse applications, and their particular focus is on abrasion resistance.

Further, the BDK valve range is ideal for general and specialised industrial applications. These range from power generation to oil and gas, petrochemicals, steel, fertiliser, pharmaceuticals and water treatment.

The BDK valve range encompasses ball, butterfly, gate, globe and check valves, as well as diaphragm, knife gate and plug valves.

“What is important to note is that we are the original-equipment manufacturer, as opposed to being a distributor of outside manufactured products. We manufacture and distribute our own products, which gives us a significant competitive advantage in the marketplace,” Steyn says.

Expanding Valve Offering
Last month, the Weir Group acquired US-based knife gate valves manufacturer Delta Industrial Valves for an enterprise value of up to $47-million.

Delta employs 70 people and generated a net income of $6.2-million over the last 12 months.

An initial consideration of $37-million will be payable on completion of the acquisition comprising $21-million in cash (funded from existing bank facilities) and $16-million in new equity, enabling the owners of Delta to share in the future benefits of the combination. Up to a further $10-million in cash will be paid over the next 18 months, contingent upon the business meeting certain profit growth targets.

The acquisition extends Weir’s presence in the mining and oil sands markets by expanding the division’s portfolio of valve products, particularly knife gate valves, for use in the transportation of slurry.

The transaction will be immediately earnings accretive, and post-tax returns (before integration costs) are expected to exceed Weir’s cost of capital in the first full year of ownership.

“Weir is a global leader in process critical products in the mining and oil sands markets and the acquisition of Delta further strengthens our comprehensive offering to customers,” says Weir Group CE Keith Cochrane.

He adds that Delta’s strong brand and reputation, together with Weir’s global capability, mean that the partnership will be able to offer customers new ways to increase efficiency at a time when the industry is focused on reducing costs and increasing productivity.

Delta Industrial Valves VP Mark Johnson says Delta is delighted to join “one of the world’s leading engineering businesses”. He says Delta will be able to take advantage of Weir’s presence in more than 70 countries, bringing its valves technology to customers worldwide.

“We see significant opportunities ahead in what remain long-term growth markets,” he concludes.