Banca de QUALIFICAÇÃO: RODRIGO SOUZA PESSOA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : RODRIGO SOUZA PESSOA
DATA : 29/04/2020
HORA: 09:00
LOCAL: Sala A5 do Departamento de Solos
TÍTULO:

Solubilization of alternative sources of potassium phonolite and verdete in mixtures with calcitic limestone and dolomitic and coffee husk, calcined at different temperatures

PALAVRAS-CHAVES:

Minerals. Potassium. Rocks. Solubilization. Fonolito and Verdete

PÁGINAS: 100
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Fertilidade do Solo e Adubação
RESUMO:

Brazil imports more than 90% of all the potassium it consumes in agriculture, currently the potassic fertilization of Brazilian soils is carried out by using soluble salts such as potassium chloride (KCl). Due to the small national production, about 7.60% of the apparent high consumption, due to the fact that Brazilian soils are poor in potassium, this demands a great consumption of these fertilizers, making Brazil a major importer of these potassic fertilizers. This situation is aggravated by the only mine in operation in Brazil, located in the Taquari-Vassouras Complex in Sergipe, which has production conditions only until 2016 (Brazil 2013).

However, Brazil has large reserves of low solubility potassium silicate rocks, with great potential to be used in agriculture as alternative sources of potassium, among these rocks we can mention the fonolito and verdete both rocks found in the state of Minas Gerais, its extraction is relatively inexpensive and the prospected volume of rocks is high. However, it is necessary to develop beneficiation technologies capable of increasing the solubilization of these rocks to supply the nutrient demand in agriculture. Thus, the objective of this work was to perform a chemical and mineralogical characterization of the phonolite and the verdete and to evaluate the efficiency of techniques and treatments in the solubilization of the potassium contained in the rocks. Characterization techniques were used for the characterization of the rocks, with X-ray diffraction and chemical analyzes of high and low potassium extraction power. Thermal treatments with different forms of calcination were carried out. After the analyzes, it was generally found that the phonolite is a rock of volcanic origin, composed mainly of microcline, orthoclasia, andesine and nepheline, distributed around the world and that presents about 9% of K2O. Verdete in turn is a rock of metasedimentary origin composed of minerals of the groups of micas, k-feldspars and quartz that can vary between 6 to 14% of K2O. Its mineralogy is composed of 37% glauconite, 24% recrystallized quartz, 14% light brown clayey matrix; 11% kaolinite, 7% other micas, such as muscovite, chlorite and biotite. After the rocks have been subjected to calcination which substantially alters the crystalline structure of the mentioned minerals, providing an increase in the availability of potassium, the

calcium calcination with high calcium content, low magnesium content with an organic matrix of coffee husks and potassium carbonate at 300 °, 600 °, 800 ° and 1000 ° C, provided an increase in the solubility of potassium when compared to the rocks without calcination.

MEMBROS DA BANCA:
Interno - 2213075 - EVERALDO ZONTA
Interno - 387263 - NELSON MOURA BRASIL DO AMARAL SOBRINHO
Externo ao Programa - 1282206 - JULIANO BAHIENSE STAFANATO
Externa à Instituição - ADÉLIA AZIZ ALEXANDRE POZZA - UFLA
Externo à Instituição - JOSE LUIZ RODRIGUES TORRES - IFBA
Externo à Instituição - PAULO CÉSAR TEIXEIRA - EMBRAPA