Purification of HgI2 for nuclear detector fabrication

The invention is directed to a process for the purification of HgI2 utilized as raw material for growing crystals of detector quality. The process involves the purification of mercuric iodide raw material utilized in the growth of high-quality crystals by the sequential steps of: synthesis of mercuric iodide from essentially pure mercury and iodine purified by repeated sublimation by melting the mercury and iodine in stoichiometric amounts in an evacuated reaction tube at a temperature of 260 to 3000C for a time period of one-half to six hours; repeated sublimation of the synthetic mercuric iodine material by subjecting the synthetic mercuric iodide material in a gradient furnace having a temperature from about 60 to 800C in the cool zone to about 100 to 1400C in the hot zone and putting the material through 6 to 30 cycles in the furnace; and zone refining of the resublimed material by subjecting the material to from 30 to 100 melting passes through a furnace having a temperature from 259 to 3000C. (LL)