The Problem

BHP Copper operates a 3,400 tons per day dry concentrate, single burner, Outokumpu flash smelting furnace at its San Manuel copper smelter in Arizona. The first six months of furnace operation were plagued by serious flooding problems. This resulted in upset conditions at the concentrate burner, leading to poor furnace metallurgy. Serious flooding problems also caused a large buildup in the waste heat boiler, which required a lengthy furnace shutdown for removal. The flow pattern in the dry charge bin was funnel flow, which occurs when a hopper is not sufficiently steep and smooth to force material to slide along the walls, or when the outlet of a bin is not fully effective, as is almost always the case when a drag chain is used as a feeder.

Jenike & Johanson's Solution

Jenike & Johanson recommended removing the existing pant-leg hopper arrangement, installing four mass flow hoppers, and lining all interior sloping surfaces with stainless steel sheet with a 2B surface finish.

To achieve a uniform velocity profile in the new mass flow bin, we evaluated the use of STAMET multi-disc feeders coupled with air slides. STAMET feeders utilize an innovative design with a single moving part that provides evenly metered output across the full width of the outlet. This unique design allows easy metering and feeding of a wide range of materials, including fine powders, at low to very high rates. The feeders are extremely rugged and experience very little wear, even with abrasive materials.

The Result

Since startup, the system has been operating reliably and has allowed the mine and processing plant to work together more efficiently and reduce production costs.

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