The Effects of Weathering on Coal Quality in the Limpopo and Soutpansberg Coalfields

Dolerites in the study area differ in mineral content, geometry, thickness, grain size and degree of alteration. Plagioclase textures indicate fractionation at different depths in the crust for the Witbank and Sasolburg intrusions, and the olivine content points to separate magma sources for two of the sills. Fine crystalline dolerite, including chilled margins and bifurcations, alters most readily.

Heat exchanger material governs how fast ice scale forms during eutectic freeze crystallisation of dilute brine. Induction time fell as thermal conductivity rose, so copper scaled first, while aluminium gave the lowest scaling rate because its low surface energy pushed ice crystallisation into the bulk. Stainless steel delayed onset but scaled heavily once nucleation started.

Compared against concrete and gabions on cost, construction time, footprint, durability and safety, the Dongalock product proved cheaper and quicker to install in small and medium incised valley bottom wetlands, and needs no heavy plant, so local enterprises can build it. Concrete still suits large wetlands carrying high water velocities.