Porosity modification related to tar sand process water

Laboratory experiments were conducted to determine the effects of tar sand process water on the mineral components of a sandstone from a known tar sand deposit and on control samples of feldspars of varying compositions. Contact with the process water increased porosity and permeability in the test samples as a result of dissolution of aluminosilicate minerals, with a corresponding precipitation of clay minerals. Once mobilized, ions from the dissolved mineral matter can be moved by a processing wave and later precipitate when geochemical conditions change. Clay minerals can occlude porosity, affecting process design and efficiency; additionally, they cause disposal and water recycling problems.