Phosphide formulation for use in the controlled production of phosphine process to generate phosphine and apparatus for the controlled production of phosphine and to generate a fumigation gas

摘要

A formulation for use in the controlled generation of phosphide comprises an intimate mixture of a particulate phosphide and a water-immiscible compound, the mixture having the consistency of an extrudable paste or a thick slurry. The phosphide, which is preferably aluminium phosphide or magnesium phosphide, comprises from 65 to 85 per cent (by weight) of the formulation. The water-immiscible compound is preferably paraffin oil, petroleum jelly, or mixture of these materials. A surfactant may be included in the formulation. Such a formulation (21, 41) can be held in a cartridge (20, 40) and added progressively to water (13, 33) in a reaction chamber (10, 30). Alternatively, the formulation can be packaged in a water-impermeable container from which a region can be removed to expose the formulation to water vapour in a gas flowing past the container. The water (13, 33) or the water vapour removes or diffuses through the water-immiscible compound from the formulation, then reacts with the phosphide to form phosphine. The phosphine, mixed with a carrier gas (usually air), may be fed into a duct (15, 55, 66) connected to a grain silo, for fumigation of grain stored in the silo.