基于热压块的不锈钢粉尘还原实验

为了从不锈钢粉尘中回收利用Fe,Cr和Ni等,对不锈钢粉尘热压块制备及其自还原过程进行了研究.在热压温度为200℃,热压压力为35 MPa条件下,抗压强度达到900 N/个以上.高温条件下,煤热解产生的挥发分可参与不锈钢粉尘还原反应,当还原温度为1 400,1 450℃时,挥发分还原作用率达到0.4.据XRD分析和热力学计算,自还原过程中含铬物质的物相转变顺序为Fe Cr2O4,Cr2O3,Cr7C3,Cr]Fe-Cr-Ni-C.当还原温度为1 450℃,烟煤中固定碳与粉尘中可去除氧的物质量的比(xc/xo)为0.72时,不锈钢粉尘热压块不能完全还原;当xc/xo大于0.8,还原20 min时,不锈钢粉尘热压块能完全还原.

Reduction Experiment of Stainless Steel Dust Based on Hot Briquetting

To efficiently recycle valuable metal such as Fe， Cr and Ni in stainless steel dust， the preparation and self-reduction of coal composite stainless steel dust hot briquette(CCSB) were researched. Under 200℃ hot briquetting temperature， 35MPa hot briquetting pressure， the compressive strength was above 900N/P. Volatile matter of coal pyrolysis could take part in reduction of stainless steel dust under high temperature， and reduction action rate of volatile matter was 0.4 at 1400 or 1450℃. XRD analysis and thermodynamic calculation results showed that product containing chromium is appeared as FeCr₂O₄， Cr₂O₃， Cr₇C₃， ［Cr］_Fe-Cr-Ni-C in turn in the self-reduction process. Under 1450℃ reduction temperature， CCSB with 0.72 of x_○c/x_○o can not completely be reduced， but CCSB with 0.8 of x_○c/x_○o or more can completely be reduced under 1450℃， 20min.