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Abstract. There are thousands of historical mine tailings and metallurgical residues present on inactive metal mining sites which have been abandoned. However, the potential release of dissolved metals, acidity, or suspended particulates from mine-waste dumps can be a serious and long-lasting problem. A variety of environmental impacts may occur at this abandoned mine sites and leading the list is acid generation, which is one of the main problems from metal mining. The objective of the present study was to characterize and evaluate the Romanian historical tailing of Sasar-Red Valley, near Baia Mare. This involved physical and chemical characterization of the materials and its acid generating potential. Sasar tailing impoundment contains 8.5 million m 3 of tailings and occupies an area of 32.5 hectares. Tailings samples were collected from different depths in three sampling points, and characterized by grain size, chemical elements concentration, elements distribution of elements in depth, paste pH, acid-base account and net acid generation tests. Acid base accounting (ABA) tests in conjunction with net acid generation (NAG) tests classified the samples into the category of 'potentially acid generating'. This paper presents a synthesis of works performed in the Improve Resource Efficiency and Minimize Environmental Footprint (REMinE) project.

Recently, the application of microwaves as a source of energy to the extractive industry has received particular attention from a large number of researchers. During the mid-1960s to 1988 most researches focused on the behavior of microwave radiant materials. These research activities continue to be important as long as the fundamental data on microwave interaction with materials is important for the successful application of technologies. This article presents the comparative cyanide tests of unprocessed and non-fired pyrite as well as the technical indicators obtained in these tests. After performing comparative cyanidation tests on unroasted and roasted pyrites at 400 and 700oC it was found that there was no significant reduction in lime and cyanide consumption for roasted pyrite at 400oC but for the roasted pyrite at 700oC the consumption of lime is reduced from 110 kg�t-1to 10 kg�t-1, cyanide is reduced from 2.8 kg�t-1 to 1.76 kg�t-1, and yields of leaching increase from 50 % for unroasted pyrite at 81 % for roasted pyrite.

The gold recovery from secondary resources is in the spotlight due to its high economic value and as the circular economy's main objective. As a valuable secondary source, the slag resulted from the gold-bearing electrolytic mud smelting contains up to 0.8-15 k g t −1 Au and 9-13 kg t −1 Ag, respectively. The gravity separation's use to concentrate gold contained by the slag causes significantly reduced reagents and energy consumptions. The diminished reacting time and the increased recovery yield due to the augmentation of contact surface between the solid phase and the leaching reagent are other important advantages. The present contribution aims to point out that a new different type of waste such as the slag resulted from the gold-bearing electrolytic mud smelting may be capitalized using gravity separation on Gemini table and Knelson concentrator, respectively. Metal recoveries up to 90-92% Au and 46-60% Ag, respectively, were obtained on Gemini table . The contributing editor for this article was Brajendra Mishra.

There are thousands of historical mine tailings and metallurgical residues present on inactive metal mining sites which have been abandoned. However, the potential release of dissolved metals, acidity, or suspended particulates from mine-waste dumps can be a serious and long-lasting problem. A variety of environmental impacts may occur at this abandoned mine sites and leading the list is acid generation, which is one of the main problems from metal mining. The objective of the present study was to characterize and evaluate the Romanian historical tailing of Sasar-Red Valley, near Baia Mare. This involved physical and chemical characterization of the materials and its acid generating potential. Sasar tailing impoundment contains 8.5 million m3 of tailings and occupies an area of 32.5 hectares. Tailings samples were collected from different depths in three sampling points, and characterized by grain size, chemical elements concentration, elements distribution of elements in depth, paste pH, acid-base account and net acid generation tests. Acid base accounting (ABA) tests in conjunction with net acid generation (NAG) tests classified the samples into the category of ‘potentially acid generating’. This paper presents a synthesis of works performed in the Improve Resource Efficiency and Minimize Environmental Footprint (REMinE) project.