title: A preliminary evaluation of volcanic rock powder for application in agriculture as soil a remineralizer.
abstract: Mineralogical and geochemical characteristics of volcanic rock residue, from a crushing plant in the Nova Prata Mining District, State of Rio Grande do Sul (RS), Brazil, in this work named rock powder, were investigated in view of its potential application as soil ammendment in agriculture. Abaut 52,400 m(3) of mining waste is generated annually in the city of Nova Prata without a proper disposal. The nutrients potentially available to plants were evaluated through leaching laboratory tests. Nutrient leaching tests were performed in Milli-Q water; citric acid solution 1% and 2% (AC); and oxalic acid solution 1% and 5% (AO). The bulk and leachable contents of 57 elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Mining waste were made up by CaO, K2O, SiO2, Al2O3, Fe2O3, and P2O5. The analysis by X-ray diffraction (XRD) showed the major occurence of quartz, anorthite, cristobalite, sanidine, and augite. The water leachable concentrations of all elements studied were lower than 1.0mg/kg, indicating their low solubility. Leaching tests in acidic media yield larger leachable fractions for all elements being studied are in the leachate of the AO 1%. These date usefulness of volcanic rock powder as potential natural fertilizer in agriculture in the mining district in Nova Prata, Rio Grande do Sul, Brazil to reduce the use of chemical fertilizers.
authors: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil. Electronic address: claudeterms@brturbo.com.br.
authors: Claudete G
authors: CG
authors: Ramos
authors: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), C/Luis Solé y Sabarís s/n, 08028 Barcelona, Spain.
authors: Xavier
authors: X
authors: Querol
authors: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors: Marcos L S
authors: MLS
authors: Oliveira
authors: Departamento Nacional de Produção Mineral (DNPM), Washington Luiz, 815, Centro, 90010-460 Porto Alegre, RS, Brazil.
authors: Karen
authors: K
authors: Pires
authors: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors: Rubens M
authors: RM
authors: Kautzmann
authors: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil. Electronic address: felipeqma@hotmail.com.
authors: Luis F S
authors: LFS
authors: Oliveira
keywords: Leaching of nutrient; Mining waste; Nutrient availability; Particle characterization; Volcanic rock