Soil geochemical signature of a calciner site, Cornwall, SW England

摘要

Historical mining activity has led to significant anthropogenic contamination of areas of Cornwall. Arsenic-rich polymetallic ores were processed by heat treatment to remove the arsenic leaving residues of metalloids and metals. To investigate the long-term impact of arsenic ore processing and refining a derelict calciner site in West Cornwall was subjected to a study by soil sampling to test for contaminant levels of elements other than arsenic and determine their spatial distribution. Within the soil profile, levels of Cu, Zn, Pb, Bi, W, U, Ga, and Cd are elevated above background concentrations. SEM examination shows that there are complex particulate grains of metals and metalloids. Statistical examination shows significant correlation between metals and arsenic as well as correlation between metals. The geochemistry of the residues indicates that the feedstock came predominantly from the Camborne-Redruth orefield. Contamination was mainly from fugitive dusts and a distinct geochemical signature is apparent in the soil surrounding the old industrial site.