EXPERIMENTAL RESEARCH ON RECOVERY OF METALS FROM STEEL DUST

对钢粉进行了蒸发焙烧，将焙烧过程中有害有色元素从铁中分离出来。我们研究了下列元素的蒸发；锌、铅、锡、铜、钠、钾和氯。我们打算在有色金属元素和铁的提取过程中作为资源加以利用。实验结果表明：(1)用CaCl_2在超过1300K的氧化条件下焙烧钢粉，铜以氯化铜的形式很好地蒸发。钢粉中的含碳量降低，导致铜的蒸发效率降低，因此在焙烧前必须将碳氧化。铅在烘烤过程中比铜更容易蒸发。粉尘中20%的锌在氧化状态下以氯化物气体的形式蒸发。(2)在1300K以上的还原条件下，加入CaCl_2，锡的蒸发继续进行。因此，灰尘中90%的锡在最佳状态下可去除。(3)锌在不添加CaCl_2的情况下在还原条件下蒸发。(4)钠和钾在氧化和还原条件下都能很好地蒸发。蒸汽香料的元素是不确定的。蒸发焙烧残渣中含铁量为40 ~ 60%，与炼铁资源相当，但不足以用于炼钢。将剩余物粉碎，然后通过磁选收集铁。铁富集率达80%，磁选铁回收率达90%。从理论上讲，从铁中分离有害元素并将其用于提取铁中的有害元素是可行的，但焙烧和分离过程相当复杂，需要一定的成本。

Evaporation roasting for steel dust, in which roasting detrimental non-ferrous elements is separated from iron, has been carried out. We have investigated evaporation of following elements ; zinc, lead, tin, copper, sodium, potassium and chlorine. We intend the non-ferrous elements and the iron to be used as resource in their extraction process. The experimental results are summarized as follows :(1) When we roast steel dust with CaCl_2 under oxidized condition over 1300K,copper well evaporates as copper chloride. Carbon containing in steel dust makes reduced condition and lead to lowers copper evaporation efficiency, the carbon must hence be oxidized prior to the roasting. Lead evaporates more easily than copper does in the roasting. Twenty percent of zinc in the dust evaporates as chloride gas under oxidized condition.(2) The evaporation of tin proceeds with mixing CaCl_2 under reduced condition over 1300K.Thereby 90% of tin in the dust is removable in the best condition.(3) Zinc evaporates under reduced condition without CaCl_2 addition.(4) Sodium and potassium evaporate well both in oxidized and reduced condition. Vapor spices of the elements is not identified.Iron content in the residue of the evaporation roasting, that depends on dust, is 40 to 60%, which is comparable with iron making resource but too low to use that in steel making. The residue is crashed, and then iron is collected by magnetic separation. Iron thus enriches up to 80% and recovery of iron in the magnetic separation is 90%. It is theoretically possible to separate the detrimental elements from iron and to use them in their extraction process but the roasting and separation processes are rather complicated and need a cost.