Thermal treatment of a potassium-rich metamorphic rock in formation of soluble K forms

dc.creatorSantos, Wedisson Oliveira
dc.creatorMattiello, Edson Marcio
dc.creatorPacheco, Anderson Almeida
dc.creatorVergutz, Leonardus
dc.creatorSouza-Filho, Luiz Francisco da Silva
dc.creatorAbdala, Dalton Belchior
dc.date2019-03-07T13:51:56Z
dc.date2019-03-07T13:51:56Z
dc.date2017-02-10
dc.date.accessioned2023-09-27T21:02:26Z
dc.date.available2023-09-27T21:02:26Z
dc.identifier0301-7516
dc.identifierhttps://doi.org/10.1016/j.minpro.2016.12.004
dc.identifierhttp://www.locus.ufv.br/handle/123456789/23801
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/8953346
dc.descriptionCountries like Brazil, China and India are highly dependent on external reserves of soluble potassium (K) minerals for the production of K fertilizers. On the other hand, the natural occurrence of potassium-rich silicate minerals in these countries, has seldom been commercially exploited until recently. Technological strategies that can increase the reactivity of these minerals can turn them into a resource for K fertilizer production. This work aimed to investigate the changes in solubility of Verdete rock (VR) after calcination with a melting agent (MA- CaCl2·2H2O) under varying temperatures of calcination and ratios (w w− 1) of MA/VR. Measurements of extractable K in water (Kwater), X-ray diffraction (XRD) and X-ray Absorption Near Edge Structure (XANES) were performed to identify new mineral phases. The Kwater increased up to 184-fold when the VR was calcined in the presence of MA. Optimization of calcination of VR to temperature of 850 °C and a 1.7 ratio (w w− 1) of MA/VR yielded Kwater values of up to 95% of total K. Potassium K-edge XANES analysis revealed changes in the molecular environment of K due to the calcination of VR at increasing temperatures. The K K-edge XANES fit to sylvite was supported by the detection of this mineral by XRD analysis at calcination temperatures ranging from 700 to 900 °C. In addition, K K-edge XANES analysis indicated the gradual formation of a new potassium-silicate mineral with increasing temperature, which the XANES analysis showed to be an amorphous-K2SiO3 (Amorphous-K2SiO3). The combination of Kwater and the residue of Linear Combination Fitting analysis (LCF) performed on the XANES data suggested the formation of an undefined K mineral phase additional to sylvite and Amorphous-K2SiO3. The calcination process was effective in producing highly soluble K mineral phases from a low solubility raw material. The end-products of the calcination procedure obtained in our work represent a promising alternative material for K fertilizer production, but further evaluation of the plant availability of the K in soils is needed.
dc.formatpdf
dc.formatapplication/pdf
dc.languageeng
dc.publisherInternational Journal of Mineral Processing
dc.relationVolume 159, Pages 16-21, February 2017
dc.rightsElsevier B. V.
dc.subjectCalcination
dc.subjectCalcium chloride
dc.subjectGlauconitic rock
dc.titleThermal treatment of a potassium-rich metamorphic rock in formation of soluble K forms
dc.typeArtigo


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