Environmental impact and potential utilization of historical Cu-Fe-Co slags

Abstract

Historical slags from the past Fe and Cu-Co production were investigated in order to evaluate either their potential for utilization or their long-term environmental risk for unsupervised old smelting areas. Here, we studied ferrous slags produced during the recovery of Fe from siderite-Cu ores in Slovakia and two different types of non-ferrous slags produced during the recovery of Cu and Co from Kupferschiefer ores in Germany. The glassy character, rare occurrence of primary silicate phases, and the lack of secondary phases in Cu slags indicate their stability for a prolonged period of time. Electron microprobe analytical work showed that the metals and metalloids (Cu, Co, Fe, Zn, Pb, As) are largely encased in droplets of matte and metal alloys and remain protected by the glassy matrix with its low weathering rate. Fe and Co slags are composed of high-temperature silicates such as wollastonite, cristobalite, as well as olivine, feldspar, quartz, leucite, pyroxene, and pyroxenoids. The presence of secondary phases attests to a certain degree metal release owing to weathering. Assuming minimal contents of metals in slags after a treatment with dilute H2SO4, slags could be used as pozzolanas for addition to cement.

Synthesis and Characterization of Novel Catalytic Materials Using Industrial Slag: Influence of Alkaline Pretreatment, Synthesis Time and Temperature

“…A typical composition of ferrous slags presented in Table 1 is dominated by Ca and Si with variable amounts of Al, Fe and Mg. The other major elements are K, Na and Ti with average amounts lower than 2 wt% [3,4].…”

The load dependence of the micro-hardness of the blast furnace slag

“…Because the dumping of the slag has a potentially undesirable impact on the environment, it is advisable to recover metals from the slags and utilize them in other ways. As demonstrated Veselská & Majzlan [4], the layers of old iron slag are generally not dangerous with regard to possible toxicity. However, they are dangerous due to the unstable subsoil.…”

Recuperação De Metais E De Ácido Sulfúrico a Partir De Uma Solução Sintética De Processamento De Minério Laterítico Utilizando Eletrodiálise

“…Desde o final da década de 80, o aumento da demanda de metais por parte da sociedade conflitou com o aumento das exigências quanto ao descarte de poluentes no meio ambiente [1,2]. Soma-se a isso o aumento da complexidade do processamento das reservas remanescentes para obtenção de metais.…”