NOVELTY - The device comprises para-xylene (PX) oxidation slag material feeding tank (1), a solid-liquid separator, a cobalt extracting device (3), a benzoic acid crude reaction tower (7), a cobalt salt reaction tower, a cobalt product discharging device (6), and an esterification reaction tower. The PX oxidation slag feeding tank is connected with the solid-liquid separator and the cobalt extracting device respectively. The solid-liquid separator is connected with a middle of the cobalt extracting device and the benzoic acid crude reaction tower.    USE - The device is useful for preparing cobalt carbonate with PX oxidation residue, where the cobalt carbonate is useful in mineral processing agents, catalysts, paint pigments, feed, micro fertilizer and ceramics.    ADVANTAGE - The device is capable of easily, safely and economically preparing the cobalt carbonate with reduced power consumption in an environmentally-friendly manner.    DETAILED DESCRIPTION - The device comprises para-xylene (PX) oxidation slag material feeding tank (1), a solid-liquid separator, a cobalt extracting device (3), a benzoic acid crude reaction tower (7), a cobalt salt reaction tower, a cobalt product discharging device (6), and an esterification reaction tower. The PX oxidation slag feeding tank is connected with the solid-liquid separator and the cobalt extracting device respectively. The solid-liquid separator is connected with a middle of the cobalt extracting device and the benzoic acid crude reaction tower. The cobalt extracting device is connected with the cobalt salt reaction tower. The cobalt salt reaction tower is connected with a cobalt product discharging device. The cobalt salt reaction tower comprises a first cobalt salt reaction tower (4) and a second cobalt salt reaction tower (5). The benzoic acid crude reaction tower is connected with the cobalt extracting device. The esterification reaction tower is connected with a PVC plasticizers discharging device.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a device for preparing cobalt carbonate with PX oxidation residue.    Para-xylene oxidation slag material feeding tank (1)    Cobalt extracting device (3)    First cobalt salt reaction tower (4)    Second cobalt salt reaction tower (5)    Cobalt product discharging device (6)    Benzoic acid crude reaction tower. (7)