Safe Removal of Arsenic Dust from Gallium Arsenide Cryst

We will make a major improvement in the safety of operation of Liquid Encapsulated Czochralskicrystal pullers used in the growth of gallium arsenide. The hazard is caused by the presence of finelydivided arsenic dust on the inside of the pullers after growth. Some of this is believed to convert toarsine. Operators remove the dust by vacuum cleaning and scrubbing with tissues, and hence areexposed to high levels of toxic and carcinogenic material. The hazard will be eliminated by chemicalremoval of the arsenic. This will eliminate the health risk to operators, decrease operator turnover (thepuller cleaning job is generally detested) and improve the economics of the process by saving the hoursspent cleaning. The economics will also be improved by reducing the volume of toxic waste andproducing it in a form that is more easily handled.