The As-removal Effects of Pyrite Including Arsenopyrite after Process for Use in Medicine.

Abstract

As pyrite is commonly associated with arsenopyrite, the use of pyrite including arsenopyrite for medicine requires close attention on arsenic toxicity. The toxicity was reduced by traditional processing operations include heating and quenching in vinegar. To verify the scientific effects of this process, pyrite containing many crystals of arsenopyrite was processed at temperatures from 450ºC to 850ºC and through as many as 5 processing cycles. Arsenopyrite completely disappeared when processed only once at 650ºC while it remained even after 5 processing cycles at 450ºC. Arsenic was most abundant in medicinal mineral samples processed at 450ºC and sharply decreased when processed at 650ºC or 850ºC. And arsenic extraction test in water was carried out from the processed pyrite medicine on the assumption that pyrite medicines with the lowest As metal content would be most desirable. Arsenic were most abundant in water extracted from medicinal mineral samples processed at 450ºC and sharply decreased when processed at 650ºC or 850ºC. But the extracted As concentrations in water exceeded drinking water standards even when processed at 850ºC. Increasing temperature promoted elimination of arsenopyrite and reduction of As in medicinal minerals and the extraction solutions. But the effects of processing cycles at the same processing temperature were not clear. Heating temperature is more important than number of processing cycles for the removal of arsenic, and it is necessary to heat pyrite to over 650ºC to remove it.