Process for high-acid normal-pressure circulating leaching of medium nickel matte

The invention relates to a high-acid normal-pressure circulating leaching process for medium nickel matte, which comprises the following steps: (1) carrying out ore grinding treatment on the medium nickel matte to obtain finely ground medium nickel matte; (2) leaching the medium matte nickel subjected to fine grinding with concentrated sulfuric acid to respectively obtain hydrogen sulfide gas and leached ore pulp; (3) the leached ore pulp is filtered and separated through a leaching filter press, and filter pressing residues and leached filter pressing post-liquid are obtained respectively; treating the leached and filter-pressed liquid by an evaporation concentrator to respectively obtain condensed water A and concentrated mother liquor; (4) the filter pressing slag enters a slurrying dissolving tank to be dissolved and is filtered by a slurrying filter press, and filter pressing copper slag and a sulfate dissolving solution containing iron, nickel and cobalt are obtained respectively; (5) carrying out iron