Efeito do extrator, concentração e tempo de contacto na solubilização do 'verdete forte' de cedro do Abaeté, Minas Gerais
Palavras-chave:
extração de potássio, ácido clorídrico, ácido cítrico, estrutura cristalina, minerais resistentesResumo
A rock phosphate from Cedro do Abaeté, Minas Gerais, Brazil, was analyzed for phosphorus, calcium and potassium extracted by hydrochloric acid or citric acid at concentrations of zero, 10-2 N and 10-1 N, and with 0.25, 1,7 and 14 days of material-solution contact. The solubilization increased with the acid concentration. Hydrochloric acid always extracted P, Ca and K more than did the citric acid. There were no variations among the contact times at 10-2 N concentration. On the other hand, at 10-1 N concentration, the citric acid increased solubilization with the contact time, whereas the hydrochloric acid gave this increase only for potassium.
It was concluded that potassium occurs in a resistent matrix while phosphorus is present predominantly as calcium phosphate.
Referências
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