Adsorção e dessorção de arsênio em solos e substratos de mineração de ouro e práticas de mitigação de drenagem ácida em colunas de lixiviação

• Autor(a) principal: Ribeiro Júnior, Emerson Silva
• Data de Publicação: 2002
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1578
• topic: Pirita; Drenagem ácida; Técnicas de recuperação; Pyrite; Acid drainage; Recovering techniques; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

This research was splited in two parts. The first one had as objectives: to adapt new methodologies to help on the understanding of As dynamic in soils and substrates; to evaluate the As adsorption and desorption in different soils and substrate from Paracatu MG. The second part had as objective to evaluate the effect of different insulating layer and geochemical barriers formation as mitigate practice of acid drainage. For the different studies, three soil samples, from region of Paracatu, were air dried, and sieved (2 mm). Additionally, two substrate (ore) from Paracatu gold mine were collect. After physic and chemical characterization, the maxima adsorption capacity of As and P (MACAs and MACP) were gotten. Sequentially, the soil As available was evaluated, after crescents As doses application, using Mehlich III and anionic resin. Both, Mehlich III and anionic resin, were adequate to evaluate the available of As. However, the Mehlich III was sensitive to soil buffer capacity. The MACAs values were bigger than MACP values, however, the linkage energy between soil and element was bigger to As then to P. In the second part, one experiment using leaching columns was done, using soil as upper layer, soil and substrate (B1) with different treatments as insulating layer, and one basal layer formed by a gold ore rich in sulfides (B2). The treatments were built using different insulating layer formed by compaction of B1, increase the bulk density of the soil by NaOH, CaCO3, and oxalic acid application. Additionally was built a treatment formed by KCl addition on the B2 substrate aiming the jarosite synthesis. Monthly leaching were done, evaluating the Fe, S, K and As quantities. The use of B1 compacted as insulating layer and KCl application as geochemical barrier was efficient to mitigate the acid drainage process. The jarosite formation is suggested by indirect evaluation. The oxalic acid, NaOH and CaCO3 were efficient to increase the bulk density of the insulating layer. However, the increase of the insulating layer using NaOH and CaCO3 were not efficient to reduce the acid drainage process.