Mineralogy and Geochemistry of Iron Tailings from Yeshan Iron Deposit, Southwest Jiangsu, China: Implications for Potential Utilization

Abstract

In this work, twenty-one core samples of tailings wastes were collected from Yeshan iron tailings pond in Jiangsu Province, China. The mineralogical-chemical properties of Yeshan iron ore tailings (IOTs) were investigated to explore potential utilization. Mineralogical investigations and mineral liberation analysis indicated that the iron tailings have complex texture and incomplete mineral liberation, suggesting further grinding can improve higher recovery. Yeshan IOTs accumulated much higher MgO originating from dolomite, therefore, it could be infeasible to utilize a large quantity of Yeshan IOTs as alternative raw meals for cement clinker or replace aggregates in concrete. 2D vertical distribution profiles created with the ordinary kriging method presented heterogeneous distributions of major elements, and the variation trends were inconsistent. The results obtained in this work provide insight for exploiting and reducing Yeshan IOTs.

Figure 1

Map showing the Yeshan iron tailings location and the sample collection sites in the tailings pond (image courtesy of Google Earth).

Figure 2

Particle size distributions of mineralogical phases.

Figure 3

X-ray diffraction patterns: (A) a typical XRD pattern of the mixture sample; (B) XRD patterns of 5 samples from borehole P1; (C) XRD patterns of 7 samples from borehole P2; (D) XRD patterns of 9 samples from borehole P3.

Figure 4

BSE images from the MLA system: (A) magnetite is locked in serpentine; (B) serpentine is enriched in coarse-grained magnetite crystals; (C) complicated intergrowth of pyrite and limonite with crisscross grain boundaries; (D) irregular siderite aggregations occur between hematite and pyrite; (E) fine-grained hematite is enriched in brucite; (F) intergrowth of chalcopyrite and serpentine.

Figure 5

Box and whisker plots for (A) major elements with contents more than 3 wt % and (B) elements with contents less than 2 wt %.

Figure 6

Major components of Yeshan IOTs, compared with four typical types of IOTs in China.

Figure 7

Kriging maps of the spatial distribution of major elements in the vertical profile of the Yeshan iron tailings pond.

Figure 8

Heat map of correlations between major elements based on Pearson correlation coefficients (n = 21). The data is the r values. Blue, white, and red colors denote strong negative correlation, weak correlation, and strong positive correlation, respectively. “**” and “*” indicate significant correlations at p < 0.01 and p < 0.05, respectively.