STABILISING AND REDUCING PERMEABILITY OF SOILS, FOUNDATIONS, WELLS OR WASTEHEAPS BY FILLING PORES, SPACES AND FRACTURES

摘要

Methods for inducing the precipitation of substantially water insoluble mineral carbonates in pores, spaces and fractures by conveying a carbon-dioxide (i.e. CO2) bearing gaseous phase or an oxidised-carbon-bearing aqueous phase into spaces where reaction with an existing or introduced fluid phase of appropriate composition occurs, or by conveying a fluid of appropriate composition into spaces where reaction of the fluid components with a fluid delivery medium occurs, or by conveying a fluid of appropriate composition into spaces under controlled physical conditions such that unassisted reaction of the fluid components occurs. The present invention also provides a method of reducing the permeability or improving the structural integrity of natural or man-made aggregates of mineral or waste materials comprising the introduction of carbon dioxide or a soluble carbonate species into the aggregate to react with a chemical compound capable of reacting with the carbon dioxide or soluble carbonate species to form a substantially insoluble carbonate within pores, spaces or fractures in the aggregate in broadly controllable geometric distributions, wherein an appropriate chemical compound capable of reacting with the carbon dioxide or soluble carbonate species to form a substantially insoluble carbonate may need to be introduced to the aggregate if not already present in suitable concentrations wherein the carbon dioxide or soluble carbonate species need not be introduced to the aggregate if already present in suitable concentrations. The present invention also provides a method of reducing the permeability or improving the structural integrity of natural or man-made aggregates of mineral or waste materials comprising the introduction of one or more reactive materials to react to form a substantially insoluble carbonate within pores, spaces or fractures.