Citation: Dedic, J.; Djokic, J.; Galjak, J.; Milentijevic, G.; Lazarevic, D.; Šarkoˇ cevi´ c, Ž.; Lekic, M. An Experimental Investigation of the Environmental Risk of a Metallurgical Waste Deposit. Minerals 2022, 12, 661. https:// doi.org/10.3390/min12060661 Academic Editor: Anthimos Xenidis Received: 9 April 2022 Accepted: 21 May 2022 Published: 24 May 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). minerals Article An Experimental Investigation of the Environmental Risk of a Metallurgical Waste Deposit Jasmina Dedic 1 , Jelena Djokic 1, *, Jovana Galjak 1 , Gordana Milentijevic 1 , Dragan Lazarevic 1 , Živˇ ce Šarkoˇ cevi´ c 1 and Milena Lekic 2 1 Faculty of Tehnical Sciences Kosovska Mitrovica, University of Priština, 38220 Kosovska Mitrovica, Serbia; jasminavdedic@hotmail.com (J.D.); jovana.galjak@pr.ac.rs (J.G.); gordana.milentijevic@pr.ac.rs (G.M.); dragan.lazarevic@pr.ac.rs (D.L.); zivce.sarkocevic@pr.ac.rs (Ž.Š.) 2 Faculty of Mining and Geology, University of Belgrade, 11000 Belgrade, Serbia; milenalekic@gmail.com * Correspondence: jelena.djokic@pr.ac.rs Abstract: The aim of this study is to investigate the environmental risk of long-term metallurgical waste disposal. The investigated site was used for the open storage of lead and zinc waste materials originating from a lead smelter and refinery. Even after remediation was performed, the soil in the close vicinity of the metallurgical waste deposit was heavily loaded with heavy metals and arsenic. The pollutants were bound in various compounds in the form of sulfides, oxides, and chlorides, as well as complex minerals, impacting the pH values of the investigated soil, such that they varied between 2.8 for sample 6 and 7.34 for sample 8. In order to assess the environmental risk, some eight soil samples were analyzed by determining the total metal concentration by acid digestion and chemical fractionation of heavy metals using the BCR sequential extraction method. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine six elements (As, Cd, Cu, Pb, Zn, and Ni). Total concentrations of the elements in the tested soil samples were in the range of 3870.4–52,306.18 mg/kg for As, 2.19–49.84 mg/kg for Cd, 268.03–986.66 mg/kg for Cu, 7.34–114.67 mg/kg for Ni, 1223.13–30,339.74 mg/kg for Pb, and 58.21–8212.99 mg/kg for Zn. The ratio between the mean concentrations of the tested metals was determined in this order: As > Pb > Zn > Cu > Ni > Cd. The BCR results showed that Pb (50.7%), Zn (49.2%), and Cd (34.7%) had the highest concentrations in mobile fractions in the soil compared to the other metals. The contamination factor was very high for Pb (0.09–33.54), As (0.004–195.8), and Zn (0.14–16.06). According to the calculated index of potential environmental risk, it was confirmed that the mobility of Pb and As have a great impact on the environment. Keywords: lead production waste; remedy; environmental risk; BCR sequential extraction 1. Introduction Mining and metallurgy waste deposits represent a risk to the environment. However, even after the remediation of the waste deposit site was performed, there was an impact of long-term heavy-metal pollution that had penetrated into the soil and nearby water flow. The metallurgical waste deposit was situated in the open space, between the tailing waste deposit of Žitkovac and the flow of the Ibar River. Primary lead and zinc metallurgy production generate lead-containing waste from lead smelters and refineries, including pyrite roasting residue, lead ash, lead slag, lead-containing dust from the refinery, lead anode slime, and lead sludge during the zinc electrowinning process, [1–3]. The authors focused on the possibilities for Pb stabilization in sludge at lower temperatures in pyromet- allurgical processes by using sulfur compounds, as well as SiO 2 , CaO, TiO 2 , and Al 2 O 3 [4]. The leaching of heavy metals, especially lead and arsenic, was investigated in secondary alkaline lead slag as form of hazardous waste due to its solubility and mobility along the depth column [5]. The authors proposed a process for As removal and Pb immobilization. Minerals 2022, 12, 661. https://doi.org/10.3390/min12060661 https://www.mdpi.com/journal/minerals