The invention relates to a method for preparing chloroiridic acid. According to the method disclosed by the invention, firstly,
metal iridium powder and
sodium chloride are fused at a high temperature, meanwhile, a little amount of
starch is added,
chlorine is introduced into the fused melt, and most
iridium powder is transformed into
iridium sodium chloride by a measure of
chlorine strengthened stirring; a little part of produced
iridium chloride gas is absorbed by using a diluted
hydrochloric acid solution; iridium
sodium chloride obtained by high-temperature chlorination
smelting reaction is merged with a diluted
hydrochloric acid absorbing solution, and then
sodium hydroxide is added for
neutralization to produce
iridium oxide, a product is filtered and washed for multiple times to remove sodion,
hydrochloric acid is added and dissolved and then concentration is performed to prepare the chloroiridic acid solution. According to the invention,
chlorine is introduced into a melt and stirred adequately, and by a measure of
smelting in a furnace
hearth, transformation of iridium is efficiently promoted, and the leaching efficiency of iridium
powder reaches 80% or above; by adding
starch,
passivation of the surface of the iridium powder in the heating process can be avoided, sufficient transformation of iridium powder is promoted, and by performing secondary absorption on
tail gas, comprehensive utilization of a hydrochloric acid absorbing solution is realized, and the comprehensive
recovery rate of iridium is increased.