Method for preparing battery-grade iron phosphate from laterite-nickel ore

The invention discloses a method for preparing battery-grade iron phosphate from laterite-nickel ore, the laterite-nickel ore and a sulfate additive are mixed and then subjected to roasting reduction, the subsequent acid leaching efficiency and the ferronickel leaching rate are improved, a leaching solution is subjected to staged oxidation iron precipitation, and anhydrous iron phosphate with more uniform particle size and higher specific surface area is obtained. The lithium iron phosphate produced by using the composite material has relatively high compaction density, initial efficiency and specific discharge capacity. The specific surface area of the obtained anhydrous iron phosphate is larger than or equal to 7.6 m < 2 >/g, the compaction density of lithium iron phosphate prepared from the anhydrous iron phosphate is larger than 2.5 g/cc, the 0.1 C discharge specific capacitance is 160-165 mAh/g, the 0.5 C discharge specific capacitance is 152-160 mAh/g, the 1.0 C discharge specific capacitance is 147-151