Preventing water flow from mine passages

摘要

A particulate solid material is deposited in the passage to form an initially water-permeable plug. The material reacts with the water to form an insoluble ppte which progressively reduces and eventually prevents flow of water through the plug. The material may be limestone or dolomite which will react with and neutralise acidic water contg. iron acids and sulphates to ppt. iron oxidies, hydrated ferric sulphate and calcium sulphate. The acidic water is thus prevented from flowing into and polluting streams and rivers.