A Highly Selective Reagent Scheme for Scheelite Flotation: Polyaspartic Acid and Pb–BHA Complexes

Zhao Wei,Wei Sun,Lei Sun,Haisheng Han,Junhao Fu,Tong Yue,Li Wang

doi:10.3390/min10060561

Zhao Wei, Wei Sun + Show 5 more

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https://doi.org/10.3390/min10060561

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Abstract

Previous studies have proved that the lead complexes of benzohydroxamic acid (Pb–BHA) are effective collectors of scheelite flotations; however, the separation of scheelite from calcite needs depressants with high selectivity. In this study, we reported a novel depressant for calcite minerals, and Pb–BHA served as the collector of scheelite. The flotation behavior of polyaspartic acid (PASP) in a scheelite and calcite flotation that uses Pb–BHA was determined via flotation experiments. Furthermore, the selective adsorption of PASP on the mineral surfaces and the effect of PASP on the adsorption of Pb–BHA on the mineral surfaces were investigated through zeta potential measurements, X-ray photoelectron spectroscopy (XPS), crystal chemistry calculations, and Fourier transform infrared spectroscopy (FTIR) measurements. Thus, PASP demonstrated high selectivity in both scheelite and calcite and contributed to the successful separation of scheelite from calcite. PASP exhibited a higher adsorption capacity and stronger chemisorption with the active sites of calcium atoms on the calcite surface. The crystal chemistry calculations indicated that the distance of the PASP functional groups matched with the calcium distance of a calcite mineral surface, which can be attributed to the selectivity of PASP. Furthermore, the adsorption of PASP impeded the adsorption of Pb–BHA on the calcite surfaces, whereas the opposite was the case for scheelite. The mutually reinforcing selectivity of PASP and Pb–BHA considerably contributes to the efficient flotation separation of scheelite from calcite.

Highlights

Tungsten and its alloys have been widely used in metallurgical machinery, petrochemical, construction, aerospace, and defense engineering [1,2,3]
Scheelite and calcite were subjected to X-Ray Photoelectron Spectroscopy (XPS) measurements before and after being treated with and calcite subjected to XPS measurements and after being with
Our flotation experiments involving pure minerals indicated that exhibits excellent selectivity for scheelite and calcite at pH = 10.0

Summary

Introduction

Tungsten and its alloys have been widely used in metallurgical machinery, petrochemical, construction, aerospace, and defense engineering [1,2,3]. The flotation separation of scheelite from gangue minerals is problematic because of their similar surface physicochemical characteristics; the traditional anion collectors adsorb onto the surface of these minerals by identifying active Ca2+. Previous studies have proved that the lead complexes of benzohydroxamic acid (Pb–BHA) were effective collectors of scheelite flotation [9,10,11]. Fluorite was scarcely collected in the flotation of the Pb–BHA complexes, implying that scheelite cannot be separated from fluorite. Calcite exhibits high recovery in the case of the Pb–BHA flotation, and it would be impossible to separate scheelite from calcite in the absence of depressants [13,14]

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