Extraction of Potassium from Microcline by Chlorination

Pablo Orosco,Manuel Ojeda,Oriana Barrios

doi:10.3390/min9050295

Abstract

A pyrometallurgical route for the extraction of potassium from microcline was investigated. The reagents used were microcline, calcite and chlorine gas. Isothermal and non-isothermal chlorination assays were performed using experimental equipment adapted for working in corrosive atmospheres. The effects of temperature and reaction time on the chlorination reaction of the microcline-calcite mixture were studied. The reaction mechanism was also investigated. The techniques used to characterize reagents and products were thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The experimental results showed that the extraction of potassium in the form of KCl begins at 700 °C for 15 min. Anorthite also starts to be produced under these conditions. The optimum conditions for quantitative extraction of potassium and selective formation of anorthite were 900 °C for 60 min.

Highlights

Potassium is the third major plant and crop nutrient after nitrogen and phosphorus
The first region can be temperature range between and 700 and corresponds towith a mass of Theobserved residues in of athese chlorination assays were420 subjected to °C, washing and filtration hotgain water
2 is not prove that this process is an efficient method for the extraction of potassium from new phases

Summary

Introduction

Potassium is the third major plant and crop nutrient after nitrogen and phosphorus. This element plays an important role in a number of physiological processes essential to growth, development, stress resistance, yield, and quality of crops [1]. On Earth, potassium is the seventh most abundant element, comprising about 2.6% of the crust volume [2]. Most of the potassium is incorporated in the crystal lattice structure of minerals and not directly available for plant uptake. Soluble potassium resources are scarce [3]. The most abundant K-bearing minerals are microcline (KAlSi3 O8 ), muscovite (KAl3 Si3 O10 (OH)2 ), and biotite (K(Mg,Fe) (AlSi3 O10 )(OH)2 ) [4]

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