The invention relates to a method for recovering
platinum group metals from high-
silicon precious iron by using CO2 and realizing material circulation, and belongs to the technical field of secondary
resource recovery of the
platinum group metals. The method comprises the following steps: after melting a high-
silicon precious iron
alloy, blowing CO2 gas in the presence of a
slag former to carry out selective desilicication
smelting to obtain an active low-
silicon precious iron
alloy, CO-containing
tail gas and silicon-containing
slag; the method comprises the following steps: combusting CO-containing
tail gas to obtain CO2 gas, dissolving the active low-silicon precious iron
alloy to prepare liquid to obtain a
platinum group solution containing iron ions, and adding
oxalic acid into the
platinum group solution containing iron ions to selectively precipitate iron ions to generate
ferric oxalate and a
platinum group metal enriched solution; the
ferric oxalate is calcined to obtain
iron oxide and CO2 gas, the
iron oxide is used for
smelting and collecting
platinum group metal to generate high-silicon precious iron alloy, and platinum,
palladium and
rhodium are refined and separated from a platinum group enriched solution; and the CO2 gas is returned to desilicication
smelting or electrocatalytic reduction to prepare
oxalic acid. According to the method, through the synergistic effect of CO2 gradient
impurity removal and
oxalic acid iron
precipitation, iron and carbon closed-loop circulation is achieved.