Electric arc furnace dust recycling apparatus and method
View Patent ↗The present technology provides an illustrative apparatus for recycle electric arc furnace (EAF) dust and method of use related to the same. The apparatus has a heat controlling region coupled to a separation volume and includes at least one magnet and a cooling region. The heating controlling region operates at a temperature sufficient to transform at least some of the EAF dust into a mixture of gaseous zinc and one or more additional metals. The magnet separates the iron-rich material from the mixture of gaseous zinc and one or more additional metals and the cooling region condenses the gaseous zinc.
1. A method for recycling electric arc furnace (EAF) dust material, the method comprising:
controlling a temperature of EAF dust material within a heat controlling region such that the temperature of the EAF dust material is sufficient to transform at least a portion of the EAF dust material into a mixture of gaseous zinc and one or more additional metals, wherein the one or more additional metals comprise iron-rich material and steel additives;
separating the iron-rich material from the mixture of gaseous zinc and one or more additional metals within a separation unit;
directing the gaseous zinc to a cooling region; and
condensing the gaseous zinc within the cooling region, wherein condensing the gaseous zinc is performed after separating the iron-rich material, and wherein the condensing the gaseous zinc comprises condensing zinc oxide into different grades that fall out at different locations within the separation unit.
2. The method of claim 1 , wherein the heat controlling region comprises a vertical structure, and wherein controlling the temperature of the EAF dust material comprises inductively heating the EAF dust material as it falls within the vertical structure.
3. The method of claim 1 , wherein the temperature sufficient to transform at least a portion of the EAF dust material into gaseous zinc and one or more additional metals is greater than about 910 degrees Celsius.
4. The method of claim 1 , wherein condensing the gaseous zinc comprises introducing cooling air to the gaseous zinc.
5. The method of claim 4 , further comprising introducing zinc oxide to the cooling air prior to introducing the cooling air to the gaseous zinc.
6. The method of claim 1 , further comprising introducing a reducing agent to the EAF dust material prior to heating the EAF dust material.
7. The method of claim 6 , wherein the reducing agent comprises one or more of carbon powder, carbon monoxide gas, or hydrogen gas.
8. The method of claim 1 . further comprising pH balancing the EAF dust material prior to heating the EAF dust material.
9. The method of claim 1 , further comprising milling the EAF dust material to reduce particle size of the EAF dust material.
10. The method of claim 1 , wherein the controlling the temperature of EAF dust material comprises controlling cooling of EAF dust material recently released from an electric arc furnace.
11. The method of claim 1 , wherein the separating the iron-rich material comprises magnetically separating the iron-rich material from the mixture of gaseous zinc and one or more additional metals.
12. The method of claim 2 , wherein the condensing the gaseous zinc within the cooling region comprises moving the gaseous zinc horizontally through the separation unit.
13. The method of claim 12 , wherein the separation unit includes one or more magnets configured to cause a horizontal displacement between the iron material and the steel additives when the iron-rich material and the steel additives fall within the separation unit.