| 主权项 |
1. A method for recycling residual heat and dust in flue gas during reclaimed copper refining, comprising a residual heat recycling apparatus and a dust recycling apparatus;
wherein the residual heat recycling apparatus consists of a counterflow heat-exchange residual heat boiler A (1), a counterflow heat-exchange residual heat boiler B (2) and a working medium preheater (3) of a counterflow heat-exchange residual heat boiler; the dust recycling apparatus consists of a water-spray scrubbing tower (4), a liquid membrane scrubber (5), an entrainment trapper (6), a draught fan (7), a settling filter A (8), and a settling filter B (9); the residual heat recycling apparatus is connected with the dust recycling apparatus by pipelines of pipe fittings in sequence, and the recycling method comprises the following steps: {circle around (1)}. First-level residual heat recycling The high temperature flue gas from reclaimed copper refining furnace enters the counterflow heat-exchange residual heat boiler A (1) and exchanges heat with the working medium in the boiler, to transfer the carrying high-temperature heat energy to the working medium in the boiler; the flue gas temperature is reduced to ≦700° C., to achieve the first-level residual heat recycling; {circle around (2)}. Second-level residual heat recycling The flue gas after step {circle around (1)} primary recycling of residual heat enters the counterflow heat-exchange residual heat boiler B (2) and exchanges heat with the working medium in the boiler, to transfer the carrying moderate-temperature heat energy to the working medium in the boiler; the flue gas temperature is reduced to ≦450° C., to achieve the second-level residual heat recycling; {circle around (3)}. Third-level residual heat recycling The flue gas after step {circle around (2)} secondary recycling of residual heat enters the working medium preheater (3) of the counterflow heat-exchange residual heat boiler and achieves counterflow heat exchange with the working medium preheater (4) of residual heat boiler, to transfer the carrying low-temperature heat energy to the working medium in the boiler; the flue gas temperature is reduced to ≦120° C., to achieve the third-level residual heat recycling; {circle around (4)}. Dust recycling via water spray The flue gas from the working medium preheater (3) of the counterflow heat-exchange residual heat boiler enters the bottom of the water-spray scrubbing tower (4), and countercurrent contacts with the water drops of spray atomization at the tower top during the ascending process, the dust enters the settling filter A (8) with the washing water, to settle and filter to achieve solid-liquid separation, the washing water is delivered to the top of the scrubbing tower (4) for recycling and the filter residues are recycled; the flue gas after washing flows out from the top of the water-spray scrubbing tower (4); {circle around (5)}. Dust recycling via a liquid membrane After step {circle around (4)} water spray, the flue gas from the water-spray scrubbing tower (4) enters the liquid membrane scrubber (5) to continue dust recycling, and enters the settling filter B(9) to settle and filter to achieve solid-liquid separation, the aqueous phase is delivered to the top of the scrubbing tower (4) for recycling and the filter residues are recycled; {circle around (6)}. Entrainment removal The flue gas after the step {circle around (5)} dust recycling via a liquid membrane enters the entrainment trapper (6) to remove the entrainment; {circle around (7)}. Emission of exhaust gas After step {circle around (6)} entrainment removal, the dust-free exhaust gas reaches the emission standard, to emit through a draught fan (7). |
