Mi Lin

TL;DR: In this paper, an integrated, definite, and systematic recovery route of full renewable metals from waste printed circuit board was proposed, which included temperature-control crushing, magnetic separation, high voltage electrostatic separation, vacuum gasification and condensation, electrolysis, and bioleaching.

TL;DR: In this paper, the authors reviewed the recent developments of the recycling techniques for nonmetallic components, including pyrolysis, supercritical fluid oxidation, chemical leaching, and direct recycling of synthetic materials.

TL;DR: HBr was the main Br-containing substances during high temperature pyrolysis of nonmetallic particles and the capture process of HBr was detailed investigated by the method of computational chemistry.

TL;DR: In this article, the authors developed a technology of ultrasonic dispersion and waterflow-magnetic separation to recover micro magnetic particles from mixed micro particles aggregates, by analyzing the relationship between aggregation energy and size of aggregates.

Abstract: With the increasing demand for lead acid batteries, there were a great number of spent lead acid batteries generated. They have the dual characteristics of resource and harm, making the recovery an important subject. In this paper, a novel approach to recover lead oxide from spent lead acid batteries by desulfurization and crystallization in sodium hydroxide solution after sulfation was proposed. During sulfation process, 85% sulfuric acid (17.786 g sulfuric acid per 2 g negative pastes) was the best for negative lead pastes, and the content of lead sulfate was up to 91.34%. For positive lead pastes, the optimal conditions were 85% sulfuric acid (17.786 g sulfuric acid per 2 g positive pastes) at 65 °C, and the content of lead sulfate was 95.69%. In the process of desulfurization and crystallization, the optimal parameters for the recovery ratio of lead oxide were 90 mg/L of solid-liquid ratio, 42 mL of mother liquor retention, and 8.24 mol/L of sodium hydroxide concentration. The recovery ratio and purity of lead oxide were 95.72% and 95.31% under the optimal conditions. Compared to pyrometallurgy and traditional hydrometallurgy, this novel approach greatly shortens the process flow. It reduces the energy consumption and secondary pollution, having great potential for industrial application.