Carbon-free low-energy-consumption zinc smelting system and method

Abstract

The invention relates to the field of low-carbon metallurgy, and discloses a carbon-free low-energy-consumption zinc smelting system and method. In order to solve the problem that the energy utilization rate is affected by high carbon consumption, high CO2 emission, high energy consumption and slag forming energy consumption in traditional pyrogenic zinc smelting (such as electric furnace zinc smelting), hydrogen is used as a reducing agent. In the reduction evaporation furnace, the hydrogen reacts with the zinc-containing oxide and the flux to generate slag and zinc-containing steam; and the zinc-containing steam enters a liquid condensing furnace, reoxidation of the zinc elementary substance is prevented by controlling system pressure and component partial pressure, and finally, liquid zinc is obtained through condensation and separation. According to the technical scheme, the advantages are remarkable, the hydrogen reduction product is water, and CO2 emission can be reduced; the hydrogen reduction reaction enthalpy change is low, reaction heat absorption and energy consumption can be reduced, the slag preparation flux amount is reduced, and the slag forming energy consumption is reduced; and in the condensation link, zinc reoxidation is effectively prevented, the product quality is improved, and low-carbon, green and low-energy-consumption zinc smelting is achieved.

Claims

1. A carbon-free, low-energy consumption zinc smelting system, characterized in that: It comprises a reduction evaporation furnace and a condensation furnace; the main structure of the reduction evaporation furnace comprises a graphite heating electrode, a feed port, a hydrogen spray port, a hydrogen chamber, a furnace gas outlet, a furnace bottom, a slag outlet and air-permeable bricks; zinc oxide and flux are added from the feed port; the graphite heating electrode is inserted from the furnace top into the furnace charge layer inside the reduction evaporation furnace for heating; after the hydrogen is preheated by the heater, a part of it enters the hydrogen chamber from the hydrogen spray port, and then enters the reduction evaporation furnace through the air-permeable bricks; the other part is pressurized and sprayed into the ascending pipe connecting the reduction evaporation furnace and the condensation furnace through the nozzle; an insulating part is arranged at the center of the furnace top of the condensation furnace, a heat-conducting condensation plate is arranged around the insulating part, a bell mouth drooping into the condensation furnace is connected to the top of the ascending pipe, the outlet of the bell mouth is facing the insulation part at the center of the furnace top, and as the tail of the bell mouth droops, the distance between the heat-conducting condensation plate and the bell mouth gradually increases.

2. The carbon-free and low-energy consumption zinc smelting system according to claim 1 is characterized in that: The heat-conducting condensing liquid plate is a silicon carbide heat-conducting plate whose temperature can be controlled.

3. The carbon-free and low-energy consumption zinc smelting system according to claim 1 is characterized in that: The graphite heating electrode can be replaced by a resistance heating component or an induction heating component to heat the reduction evaporation furnace charge layer.

4. A carbon-free and low-energy consumption zinc smelting method, characterized in that: The following steps are involved: Zinc oxide and flux are added to a reduction evaporation furnace, and reduction smelting is performed using hydrogen as a reducing agent. In the reduction evaporation furnace, a reaction of ZnO+H2=Zn+H2O occurs to generate slag and zinc-containing vapor; the zinc-containing vapor is introduced into the condensation furnace through an ascending channel; the hydrogen is preheated by a heater, a portion of which is passed into the hydrogen chamber from a hydrogen spray port at the bottom of the reduction evaporation furnace, and then enters the electric furnace through the air-permeable bricks at the bottom of the furnace, and reacts through the charge from bottom to top; the other portion is pressurized and sprayed into the ascending pipe through a nozzle and carries the zinc-containing vapor into the condensation furnace. A bell mouth is connected to the top of the ascending pipe; the tail of the bell mouth hangs down into the condensation furnace; the outlet of the bell mouth faces The central insulating part of the furnace top of the condensation furnace 200; a heat-conducting condensation plate is arranged around the central insulating part of the furnace top, and as the tail 15 of the bell mouth droops, the distance between the heat-conducting condensation plate and the bell mouth gradually increases, so that the zinc vapor carried by the hydrogen first hits the insulation material part of the furnace top, and then flows into the condensation furnace along the guide channel formed by the bell mouth and the heat-conducting condensation plate. Since the guide channel formed by the bell mouth and the heat-conducting condensation plate is gradually expanded, the flow rate and pressure of the zinc vapor decrease during the flow process, and the zinc vapor exchanges heat with the heat-conducting condensation plate in the guide channel to cool down and condense into liquid, and falls into the zinc liquid pool in the condensation furnace along the tail of the bell mouth.

5. The carbon-free and low-energy consumption zinc smelting method according to claim 4, characterized in that: The heat-conducting condensing liquid plate is a silicon carbide heat-conducting plate whose temperature can be controlled.

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