Acidic mine water treatment without lime
South African Coal Estates (SACE) is a division of Anglo Coal and operates the coalmine at Landau Colliery in South Africa.
Processing of the coal results in a sulphate-rich effluent. Part of the sulphate is removed with lime precipitation but this produces an effluent that is oversaturated with gypsum. As a result, scaling occurred piping that resulted in high maintenance costs.
In 2003, Paques commissioned a SULFATEQ™ plant that removes seven tonnes of sulphate per day from 3000 m3 per day. Sulphate is removed to 300 mg/l and metals like iron and manganese are removed. The water is re-used as process water on the site.