Study on the New Melting Process of Iron-and Steel-making Dust

巴西合作研究人员研究了高炉炼铁和电弧炉工艺中产生的粉尘的物理化学性质。对于前者，不含锌，由该粉尘生产的具有碳质材料的冷固结球团据报道具有足够的强度和还原性，并且没有膨胀和破碎，因此被证明是用于气体还原和熔融还原工艺的良好原料。研究了（Zn，Fe，Mn）Fe_2O_4的强度和还原性。结果表明，当加热到1060 ℃时，Zn会发生异常膨胀，当加热到1200 ℃以上时，Zn的脱除率达到95%以上，而在熔融还原过程中，约有70%的Zn以ZnO的形式蒸发并富集在粉尘中。所得粗锌可作为炼锌原料，日方合作研究人员正在开发焦炭过滤分离锌的工艺， ...更多信息 从铁NC。在该方法中，电弧炉粉尘中所含的锌以复杂的尖晶石结构可以在加热超过1000 ℃的焦炭移动床中蒸发，并在冷凝器中以液体锌的形式回收。另一方面，铁在焦炭床中以固态还原，并与焦炭一起排出，在常规或熔融还原炼铁工艺中回收。通过使用焦炭填充床导致高效分离。然而，电弧炉粉尘含有大量的亚微米颗粒。在这项研究中，我们研究了这种亚微米颗粒的过滤，通过使用焦炭过滤过程的冷模型。此外，还对利用化学反应从熔融炉渣中回收热能并使炉渣颗粒尺寸均匀进行了初步研究。用旋转杯式雾化器的准热态模型研究了石蜡的雾化，并对高温熔渣的雾化进行了试验。蜡雾化得到了粒度均匀的细颗粒（约0.7mm），渣粉化也得到了细颗粒，为开发实用工艺提供了积极的依据。少

Brazilian cooperative researchers studied physico-chemical properties of dusts generated in both BF ironmaking and EAF processes. For the former which does not contain zinc, cold bonded pellets having carbonaceous materials, produced from the dust are reported to have enough strength and reducibility as well as no swelling and broken out therefore being proved as sound raw materials for both gas reduction and smelting reduction processes.For the EAF dust which contains considerable quantity of the complex spinel of (Zn, Fe, Mn)Fe_2O_4, strength and reducibility have been studied. As the results, abnormal swelling was found to occurs when it was heated to 1060C, 95%Zn was removed when it was heated over 1200C, and about 70% Zn was vaporized as ZnO and concentrated in dust when it was processed in smelting reduction. The crude zinc obtained can be used as raw materials for zinc smelting.Cooperative researchers in Japanese side are developing a coke filter process for the separation of zi … More nc from iron. In this method, zinc contained in the EAF dust as complex spinel structure can be evaporated in coke moving bed heated over 1000 C and recovered as liquid zinc in a condenser. On the other hand iron is reduced in the coke bed in solid state and discharged together with coke and recovered in conventional or smelting reduction ironmaking processes.Behavior of over micron particles has been studied in our lab. resulting in high efficiency separation by using a coke packed bed. However, EAF dust contains high quantity of sub micron particles. In this study, we investigated filtration of such sub micron particles by using a cold model of the coke filter process. However, complete result has not yet obtained.In addition, a fundamental study has been made on the recovery of thermal energy from molten slag together with uniformly sized fine slag particles applying chemical reaction. Atomization of wax was studied by using a quasi-hot model of a rotating cup-atomizer and atomization of high temperature molten slag has also tested. Fine particles of considerably uniform size (about 0.7mm) were obtained for wax atomization and fine particles were also obtained for slag pulverization, which provided a positive basis for developing a practical process. Less