Polythionate formation during uranium recovery from sulphide flotation concentrate

Abstract

Uranium recovery by resin-in-pulp (RIP) from sulphide-bearing material was found to be adversely affected by polythionate formation due to partial oxidation of sulphide minerals. Polythionates are loaded more selectively by the conventional strong-base resins used at uranium plants.A study was undertaken to identify whether polythionates are formed during upstream processing, leaching, or ion exchange recovery steps. It was found that polythionate formation could be minimized by shortening of the leach time, optimizing oxidant and acid addition, minimizing delay between leaching and RIP, and maintaining the neutralization and adsorption retention times as short as possible.These insights could prompt the development of mitigation strategies on commercial plants to reduce or avoid the formation of polythionates and the adverse impact it has on uranium recovery. uranium recovery, resin-in-pulp, polythionate formation.* Mintek, Randburg, South Africa.

Selective Recovery of Copper from the Mixed Metals Leach Liquor of E-Waste Materials by Ion-Exchange: Batch and Column Study

“…The value of τ (min) in Table 5 represents the time for the Cu concentration in the column effluent to reach 50% of its final level. However, a higher value of τ (min) signifies better performance of the column as similarly reported in the literature [53,54]. Therefore, these experimental data were found to be well-fitted with the Yoon-Nelson model with R 2 values greater than 0.94.…”

Efficient Metal Extraction from Dilute Solutions: A Review of Novel Selective Separation Methods and Their Applications

“…After the loading step, the reverse reaction, transferring ions from the resin to the aqueous phase, can also be performed by introducing appropriate reagents to the loaded resins [123]. The IX process has been evaluated for wastewater treatment [121,[124][125][126] and metal extraction/removal from leach solutions, including uranium [127][128][129][130], PGMs [119,[131][132][133], copper [134][135][136][137][138], and chromium [139][140][141][142].…”

Analytical and semi‐analytical kinetics models for design and optimization of double‐resistance resin in pulp and carbon in pulp processes with both reversible and irreversible nature

“…can increase limitlessly. In fact, in a RIP process of uranium and nickel, the upper limits of φ s have been reported as 0.15 and 0.3, respectively . For the gold RIP, lower values of holdup, as low as φ s = 0.01, are used, but in the gold CIP φ s is chosen up to 0.05…”

“…Adsorption in stirred tank reactors (CSTR) in the form of resin in pulp (RIP) or carbon‐in‐pulp (CIP) is an economically attractive process for recovery of uranium, gold, and base metals (e.g. Cu and Ni), from their low grade ores. Typical concentrations of target metal ions in the RIP and CIP processes is in the (mg/L) range, and volume of the feed liquor tremendous; thus, attaining a reasonable throughput involves deploying of a countercurrent cascade, with 6–12 reactors in series .…”

“…Modelling of multistage adsorption in the RIP and CIP processes is often carried out through one of the three following approaches: the McCabe‐Thiele equilibrium method, rigorous numerical kinetics models, and approximate analytical models. Unfortunately, all of these approaches have their respective drawbacks as follows.…”