Influence of calcination temperatures on lithium deportment by screening hard rock lithium.

Calcination of spodumene is a pre-treatment stage in preparation for sulfation roasting and leaching in lithium recovery. During calcination, α-spodumene (less reactive, monoclinic crystal structure) is converted to β-spodumene (more reactive, tetragonal crystal structure). A third, metastable γ-phase has been identified at lower temperatures than full conversion to the β-phase.

Lithium deportment by size of a calcined spodumene ore.

Calcination of spodumene is used to convert α-spodumene to more reactive β-spodumene, has been shown to greatly impact the physical characteristics of some of the components in the ore. This work investigates the energy efficiency of different grinding circuits used for upgrading the lithium content in the finer fraction of the calcined spodumene ore. The results showed that closed-circuit grinding resulted in 89% lithium recovery of the finest size fractions (- 0.

Effect of calcination on coarse gangue rejection of hard rock lithium ores.

Processing of spodumene ores requires calcination as a compulsory pre-treatment to convert α-spodumene to a more reactive β-spodumene phase. This transformation takes place at an elevated temperature of above 900 °C and results in a 30% volumetric expansion of the mineral and the product having highly altered physical properties. This work examines these induced properties and the effect of calcination on lithium grade deportment with particle size.

A paper-based whole-cell screening assay for directed evolution-driven enzyme engineering.

Directed evolution has become an important method to unleash the latent potential of enzymes to make them uniquely suited for human purposes. However, the need for a large reagent volume and sophisticated instrumentation hampers its broad implementation. In an attempt to address this problem, here we report a paper-based high-throughput screening approach that should find broad application in generating desired enzymes.

Enzyme-based detection of epoxides using colorimetric assay integrated with smartphone imaging.

Epoxides are widely used chemicals, the determination of which is of paramount importance. Herein, we present an enzyme-based approach for noninstrumental detection of epoxides in standard solution and environmental samples. Halohydrin dehalogenase (HheC) as a biological recognition element and epichlorohydrin as a model analyte were evaluated for sensing.

A review on current practices and emerging technologies for sustainable management, sequestration and stabilization of mercury from gold processing streams.

This paper presents an overview of unit processes that lead to potential mercury contamination during gold processing, which can pose serious health, environmental and technical concerns. Mercury release in gold processing streams is attributed to its dissolution from mercury bearing gold ores during cyanide leaching, and its mobile nature in the subsequent stages (e.g.

The Stefan-Reynolds Model and the Modified Stefan-Reynolds Model for Studying Bubble-Particle Attachment Interactions in the Context of Flotation.

Bubble-particle attachment is the key step for successful flotation. Modeling of attachment interactions between air bubbles and particles after their collision can be analyzed using the Stefan-Reynolds model (immobile bubble surfaces) and the modified Stefan-Reynolds model (mobile bubble surfaces). However, these models have been rarely used, and the limitations of these models have not yet been reported.