Turning mine waste into a ceramic resource: Plombières mine tailing case

<p>Mining and quarrying waste is considered the second largest waste stream in Europe. According to Eurostat, in 2018, this extractive waste accounted for over a quarter of all the EU-27 waste output (26.2%). The accumulation of this type of waste in tailing dams or waste rock piles, with no end-use, can pose as a significant environmental and health hazard as well as a resource loss. Sulphidic mine waste processing residues (tailings) pose a large challenge, as their content in hazardous metalloids and sulphates tend to become more chemically available, leading to the generation of acid mine drainage. Apart from the hazardous metalloids and sulphates, these mine tailings contain valuable base, precious and critical metals which can be used in different technological applications. Moreover, silicates and clay minerals are amongst the most common and abundant minerals in sulphidic mine tailings, which indicates that after pre-treatment, if necessary, they can be used in different ceramic building applications (e.g. roof tiles and blocks) for an increasing world’s population.</p><p>Plombières Zn-Pb inactive mine (Eastern Belgium), was exploiting an ore deposit between 1844-1882 and after closure of the mine, imported ores were smelted at the Plombières site until 1922. The dumped material from the mining operations consist of mainly mine waste and metallurgical waste, such as tailings and slags, from the processing plants. The goal of the present study is to evaluate the potential use of (uncleaned) Plombières tailing material in 3 different ceramic products (roof tiles, blocks and pavers), with different compositions and firing temperatures, taking into account production parameters, product quality and environmental compliance in Flanders (Belgium).</p><p>After a detailed physical, mineralogical, chemical, thermal and environmental characterisation of the Plombières mine tailing material, as well as of the replaced raw materials, one company-specific blend has been modified on a lab scale for each ceramic product, by partly or totally replacing some primary raw materials (mainly clay and sand) by 5%, 10% and 20% of Plombières fine tailing material. The shaping, drying and firing behaviour of lab test pieces was assessed and compared to the standard, as well as the required technical, aesthetical and chemical properties of each ceramic product. Furthermore, environmental compliance tests (column leaching test) were performed on the fired test pieces of all the ceramic products. The column leaching test is performed considering a 2<sup>nd</sup> life scenario where shaped building products are demolished and can be recycled as granulates (non-shaped building products).</p>

Prediksi Laju Pembentukan Air Asam Tambang dengan Metode Column Leaching Test

Prediction of Acid Mine Drainage Forming using Method of Column Leaching Test. One of the environmental problems in coal mining activities is the formation of acid mine drainage. Prediction of the formation of acid mine drainage is important as an effort to control environmental impacts. Acid mine water occurs with interactions between potentially acid-forming material with oxygen, bacteria and water. Objective of study is to analyze the potential for acid mine drainage forming based on material characteristics. The research method was carried out using static and kinetic tests. The static test method classifies materials according to the ability to produce clean acids with observed parameters such as paste pH, total sulfur, Acid Neutralizing Capacity (ANC), Net Acid Generation (NAG), Maximum Potential Acid (MPA), and Net Acid Producing Potential (NAPP). The Kinetic test method predicts the rate of acid-forming of a material. The kinetic test uses the Column Leaching Test Method by using material with composition designed to represent field condition. The kinetic method parameters are pH, electrical conductivity, acidity, alkalinity, sulfate content, and dissolved metal content (Fe, Mn, and Cd). Results of the static test classified the material into NAF Non-Acid Forming (NAF), Potential Acid Forming (PAF) and Uncertain (UC) material categories. The results of the Column Leaching Method classified the material into categories of potential and no potential to form acid mine water. The columns that have the potential to form acid mine drainage occur in columns with large amounts of tonnage of PAF material or those in the upper layer so that it reacts with oxygen. The columns that have no potential to produce acid mine drainage in columns with PAF material are in the middle layer or mixed with NAF material.

Immobilization of Lead from Pb-Contaminated Soil Amended with Peat Moss

Immobilization of lead (Pb) using soil amendments can reduce Pb toxicity and bioavailability in soil. This study evaluated Pb immobilization in a Pb-contaminated soil by using peat moss through various tests. The Pb-contaminated soil (2000 mg Pb·kg−1) was amended with 1%, 5%, and 10% of peat moss to immobilize Pb in the soil. The immobilization properties of Pb in the contaminated soil were evaluated by a column leaching experiment, a microcosm test, and a batch incubation test. Peat moss significantly reduced the Pb leaching in all of the experiments and more effectively reduced mobility and toxicity of Pb in the column leaching and microcosm tests than bioavailability in the batch incubation test. The immobilized lead from the soils amended with 1%, 5%, and 10% of peat moss was 37.9%, 87.1%, and 95.4% from the column leaching test, 18.5%, 90.9%, and 96.4% from the microcosm test, and 2.0%, 36.9%, and 57.9% from the NH4NO3extraction method, respectively, indicating that peat moss can be effectively used for the remediation of Pb-contaminated soil.