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OverviewThis dissertation, Thermal Incorporation Behavior During the Reduction and Stabilization of Chromium Wastes by Jun, Yang, 楊駿, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The possibility of employing periclase to stabilize chromium in chromium wastes into spinel-based ceramics through thermal method was investigated by heating mixture of simulated chromium waste and magnesium oxide. Different types of magnesium oxide precursors were introduced to incorporate chromium oxide into magnesiochromite (MgCr2O4) ranging from 550 C to 1350 C. Magnesium oxide precursors of both types can effectively incorporate chromium oxide but via different mechanisms. Three main factors that can affect the leaching behavior of MgCr2O4 were studied, which are 1) the influence of different precursors; 2) the influence of cooling rate of sintered samples; 3) the influence of annealing temperature of sintered samples. Results revealed that samples of larger particle size had better leaching performance. Fast cooling rate, as well as high annealing temperature, could prohibit the formation of chromium(VI) during thermal treatment process. The comparison of prolonged both acidic and alkaline leaching tests of chromium oxide and magnesiochromite demonstrated superior stabilization performance of MgCr2O4 in stabilizing chromium. This study confirmed the feasibility of applying periclase to stabilize chromium and suggested optimistic conditions for processing chromium-containing wastes under thermal treatment methods. Hexavalent chromium waste (simulated with CaCrO4) was successfully reduced to trivalent chromium with silicon carbide (SiC) under thermal conditions. A combination of SiC and MgO can reduce hexavalent chromium to trivalent chromium and stabilize trivalent chromium into MgCr2O4 through a one-step thermal treatment. Subjects: Hazardous wastes - StabilizationMetal wastes Full Product DetailsAuthor: Jun Yang (Southeast University, Nanjing, China) , 楊駿Publisher: Open Dissertation Press Imprint: Open Dissertation Press Dimensions: Width: 21.60cm , Height: 0.50cm , Length: 27.90cm Weight: 0.231kg ISBN: 9781361014363ISBN 10: 1361014369 Publication Date: 26 January 2017 Audience: General/trade , General Format: Paperback Publisher's Status: Active Availability: Temporarily unavailable The supplier advises that this item is temporarily unavailable. It will be ordered for you and placed on backorder. Once it does come back in stock, we will ship it out to you. Table of ContentsReviewsAuthor InformationTab Content 6Author Website:Countries AvailableAll regions |