Direct Extraction of Ni(II) from Acidic Polymetallic Sulfate Media with a Novel Synergistic Extraction System of DNNSA-MSL211

Abstract

Direct extraction of Ni(II) from Fe(III), Al(III), Ca(II), Mg(II), and Mn(II) is a bottleneck issue in the hydrometallurgy processes of laterite-nickel ore, spent batteries, and other secondary sources. One of the biggest challenges in achieving direct extraction of Ni(II) is the lack of stable and efficient extractants. Hence, a novel bipyridine extractant MSL211 was designed and synthesized in this paper. With its strong steric resistance and electrostatic interaction, MSL211 can form a stable eight-membered chelating ring with Ni(II), thereby having a high bonding ability toward Ni(II). Therefore, based on the high bonding ability of MSL211 toward Ni(II) and the low extraction capacity of DNNSA for Fe(III), an efficient synergistic extraction system of DNNSA-MSL211 was proposed. The synergistic extraction system of DNNSA-MSL211 realizes direct extraction of Ni(II) from Fe(III), Al(III), Ca(II), Mg(II), and Mn(II) without neutralization, precipitation, and solid/liquid separation processes, which are inevitable but problematic processes in the current hydrometallurgy processes for removing Fe(III), Al(III), and Mn(II). The effects of the molar ratios of DNNSA:MSL211, shaking time, temperature, O/A ratios, and equilibrium pH on the extraction behavior of Ni(II) were investigated. Under optimum conditions, the extraction efficiency of Ni(II) was as high as 97.62%, and the separation coefficient of Ni(II) over all impurities was greater than 400. To elucidate the mechanism of the high selectivity of DNNSA-MSL211 toward Ni(II), DFT calculations were carried out to calculate the binding energy (ΔE) and Gibbs free energy (ΔG(ext)) of the extraction process. Furthermore, this paper investigated the entire ″extraction-stripping″ process, demonstrating that the synergistic extraction system of DNNSA-MSL211 avoids neutralization, precipitation, and solid/liquid separation processes, minimizes hazardous waste generation, and shortens process flow while meeting the objectives of sustainable and clean production.

Insight into the Mechanism of Cobalt-Nickel Separation Using DFT Calculations on Ethylenediamine-Modified Silica Gel

“…With the growth of the electric vehicle rechargeable battery market, the consumption of cobalt and nickel is expected to increase dramatically, which may lead to a significant increase in their supply risks [1][2][3][4]. Therefore, improving the recovery efficiency of cobalt and nickel in secondary resources is one of the sustainable strategies to alleviate its supply risk [5][6][7][8].…”

Extraction Behavior and Mechanism of Tungsten and Molybdenum by a Novel Primary Amine Extractant NNA

“…Oxa-Michael addition reactions of alcohol with long carbon chains to acrylonitrile have been widely reported for decades, − which can be carried out easily under alkali-catalyzed conditions at room temperature. Zhong reported a series of syntheses of Oxa-Michael additions under mild conditions .…”

A green and efficient process for the stepwise extraction of Cu, Ni, Co, Mn, and Li from hazardous waste with a novel solvent extraction system of D2EHPA-NNPA

“…28,29 These problems mainly result from the weak extractive ability, low bonding ability, and low chemical stability of commercial pyridine derivative extractants. 30 In addition, compared with organophosphorus extractants, DNNSA is not widely utilized in the hydrometallurgical industry due to its large molecular weights, high viscosities, high prices, and poor extraction capacity. Because of these drawbacks, the SSX system of DNNSA and pyridine derivative extractants is rarely used in industry.…”