School of Resources and Environmental Engineering, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Anhui University, Hefei 230601, PR China; School of Earth and Space Sciences, CAS Key Laboratory of Crust-Mantle Materials and the Environments, University of Science and Technology of China, Hefei 230026, PR China.
School of Earth and Space Sciences, CAS Key Laboratory of Crust-Mantle Materials and the Environments, University of Science and Technology of China, Hefei 230026, PR China.
Ecotoxicol Environ Saf. 2021 Aug;219:112321. doi: 10.1016/j.ecoenv.2021.112321. Epub 2021 May 12.
Slag tailings are produced by "cooling-grinding-ball milling-flotation" and other processes of slag, while slag is produced by the flash smelting of the original ore. The utilization and environmental hazards of arsenic in slag tailings have become a focus of attention. This study on slag tailings reveals the presence of arsenic in copper smelting tailings from the mineralogy and leaching perspectives, and the noncarcinogenic and carcinogenic risks of arsenic to the human body were assessed by using the USEPA health risk model. The surface particles of the slag tailings were unevenly dispersed, and the mineral crystals were relatively complete. A small amount of secondary minerals had grown on the mineral surface. Most of the fine particles adhered to the surface of the main mineral to form inclusions. The mineral composition of the slag tailings was dominated by maghemite (FeO) and fayalite (FeSiO), and the arsenic-bearing minerals were unevenly distributed, where As (Ⅴ) fine particles were embedded in maghemite, amorphous phase and fayalite. There was a large amount of residual arsenic in the slag tailing particles, and the leaching content of arsenic in the toxicity leaching procedure was always lower than the limit of 5 mg/L. The health risk to the exposed population was evaluated by the USEPA health risk model. Since the exposed population in the industrial land is mainly adults, it is determined that the tailings will not cause harm to children's health. In this evaluation, the exposure duration (length of service of the workers) of 30 years, exposure frequency of 314 d/y and body weight of 60 kg (average weight of the workers) were taken as the parameters of three exposure pathways: hand-oral ingestion, respiratory system inhalation and skin contact. Therefore, longer activity time of the workers in the tailing workshop corresponds to a higher HI (hazard index). Although the arsenic in the slag tailings had a certain degree of bioavailability, it was not sufficient to adversely affect human health.
钢渣尾矿是通过“冷却-磨球-浮选”等工艺从钢渣中产生的，而钢渣是由原矿闪速熔炼产生的。钢渣尾矿中砷的利用和环境危害已成为关注的焦点。本研究从矿物学和浸出角度揭示了铜冶炼尾矿中砷的存在，并采用美国环保署健康风险模型评估了砷对人体的非致癌和致癌风险。钢渣尾矿的表面颗粒不均匀分散，矿物晶体相对完整。矿物表面生长了少量次生矿物。大部分细颗粒附着在主矿物表面形成包裹体。钢渣尾矿的矿物组成以磁赤铁矿（FeO）和铁橄榄石（FeSiO）为主，含砷矿物分布不均匀，其中 As（Ⅴ）细颗粒嵌入磁赤铁矿、非晶相和铁橄榄石中。钢渣尾矿颗粒中残留大量砷，毒性浸出程序中砷的浸出含量始终低于 5mg/L 的限值。采用美国环保署健康风险模型对暴露人群进行健康风险评估。由于工业用地中的暴露人群主要是成年人，因此确定尾矿不会对儿童健康造成危害。在该评价中，将暴露期（工人工龄）30 年、暴露频率 314d/y 和体重 60kg（工人平均体重）作为三种暴露途径（手口摄入、呼吸系统吸入和皮肤接触）的参数。因此，尾矿车间工人的活动时间越长，HI（危害指数）越高。尽管钢渣尾矿中的砷具有一定的生物可利用性，但不足以对人体健康产生不利影响。
