Ian Peggs, President, I-CORP INTERNATIONAL, writes in the November issue of International Mining that for cost reasons there has been a move away from stainless steel mixer/settlers to lower cost concrete basins lined with high density polyethylene sheet/geomembranes. The concrete provides the required strength and the HDPE functions, or should, solely as a barrier to protect the concrete.

The HDPE may be in geomembrane form, smooth on both sides, and up to 3 mm in thickness. In thicker (5 or 6 mm) panels it may have knobs on one side and is made the former of the inside wall such that the poured concrete will cure around the knobs and hold the sheet in intimate contact with the wall. The smooth geomembrane is loose laid inside the concrete basin. Readers are encouraged to share their experiences with us. The picture shows an MC Process SX mixer-settler being installed.