[PDF] Plating Waste Sludge Metal Recovery eBook

Author : Malcolm T. Hepworth
Publisher :
Page : 198 pages
File Size : 20,35 MB
Release : 1985
Category : Metal coating
ISBN :

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The U.S. Army Toxic and Hazardous Materials Agency has requested that AMAX Extractive Research & Development, Inc. conduct a five-phase program to review literature on the current state-of-the-art in metal recovery from plating wastes, to propose a typical plating sludge composition and aging treatment in lieu of actual U.S. Army plating wastes), to develop a research and design test plan for treating this typical plating sludge, to conduct the test program, and to summarize the results in a final report. The final report proposes a sulfuric acid leach of hydroxide plating sludges, containing copper, cadmium, zinc, nickel, iron, and chromium, to extract greater than 99 percent of the heavy metal values, followed by lime treatment of the resulting filter cake to render it nonhazardous to EP testing. The sulfuric acid leach extract may be treated by selective sulfide precipitation at a controlled pH regime in order to produce a mixed sulfide of copper and cadmium with most of the zinc present in the original extract separate from a leach liquor containing more than 98 percent of the chromium, which does not form a sulfide precipitate, Nickel and iron are not selectively separated under the sulfide precipitation conditions. However, a solvent extraction process using di(2-ethyl-hexyl) phosphoric acid can be used for recovering nickel, iron, and chromium from the resulting filtrate. Originator-supplied keywords: Plating sludge, Acid leach, EP toxicity, Metals, Separation, Extraction, and Recovery.

Author : Clyde S. Brooks
Publisher : CRC Press
Page : 286 pages
File Size : 46,80 MB
Release : 2017-11-29
Category :
ISBN : 9781315895352

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This book is offered as a practical primer on the hydrometallurgy of nonferrous metal reclamation from industrial wastes, as well as a brief discussion of pyrometallurgy, biological, and other separation processes. The objectives are to acquaint nontechnical readers with the subject as well as providing a detailed survey of current research and industrial practice to technical readers concerned with the management of industrial waste.

Author : Vasanthi Sethu
Publisher : LAP Lambert Academic Publishing
Page : 144 pages
File Size : 46,98 MB
Release : 2010-03
Category :
ISBN : 9783838346090

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This book gives a comprehensive discussion on the removal of heavy metal ions from electroplating wastewater sludge using acid dissolution. Hydrochloric acid, nitric acid and aqua regia solutions were used to dissolve the metals at various reaction conditions. Metals that were tested include Silver, Aluminium, Copper, Tin, Iron, Nickel and Zinc. The optimal recovery values obtained for the above metals were 99.5%, 72.6%, 99.6%, 55.4%, 19.4%, 4.97% and 6.4% respectively. The dissolution process was greatly influenced by the reagent type and reaction temperature. Results obtained were optimised with a statistical software called DOE PRO, where a dissolution model of each metal species was obtained. All models showed good confidentiality and can be used as a tool for future studies for metal extraction from wastewater sludge.

Author : John Holroyd
Publisher :
Page : 71 pages
File Size : 22,93 MB
Release : 1978
Category : Electroplating
ISBN :

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Bench scale experimentation was initiated to evaluate the solubilities and sludge characteristics associated with selected heavy metals and their hydroxides for both homogeneous and heterogeneous solutions. Data suggests that in a mixed-metal solution, mixed-metal co-precipitants form and the point of zero charge (PZC) for these precipitants depends upon the specific metal content of the colloidal precipitants. In general the presence of chromium (III) depresses the overall PZC while nickel and cadmium, when major waste components, tend to raise the PZC. Aging was found to impact chromium hydroxide dewatering but it is not clear that the theoretical aspects of aging chemistry can be used to predict changes. High molecular weight anionic polymers were effective in conditioning metal sludges with respect to cake formation/filtrate clarity but help dewatering rates very little. Previously developed relationships for inorganic sludges which allowed predictions about sand bed, centrifugation, and vacuum filtration dewatering processes based on gravity thickening data were found to hold for metal sludges. Based on these relationships and the laboratory data gathered here it is concluded that vacuum filtration is the only reasonable process to insure a handleable sludge. If direct reclamation of the metals from the mixed hydroxide slurry is to be attempted centrifugation may be employed. Based on a literature review and a basic economic evaluation, liquid/liquid extraction was recommended for further study as the metal recovery process of choice. (Author).

Author : PRC Environmental Management, Inc
Publisher : William Andrew
Page : 232 pages
File Size : 27,92 MB
Release : 1989-12-31
Category : Crafts & Hobbies
ISBN :

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"From the Foreword: " This book presents the results of a waste audit study for the metal finishing industry. The study, carried out for the State of California but applicable for metal finishers elsewhere, identifies opportunities for waste reduction available to the metal finishing industry and develops procedures that can be used by metal finishers to assess their own waste reduction opportunities. The study emphasizes technologies available to small- and medium-sized metal finishing plants. Typically, these shops operate a variety of physical, chemical, and electrochemical processes. Chemical processes include degreasing, cleaning, pickling, etching, coating, and electroless plating. Electrochemical processes include plating and anodizing. The tasks included in the study were: (1) selecting metal finishing plants to include in the study, (2) performing a waste audit at each selected plant, (3) developing recommendations for implementing waste reduction technologies at each audited plant, (4) discussing with facility representatives the feasibility of implementing the waste reduction recommendations, and (5) developing this waste audit study report and methodology. The study identifies three categories of waste reduction technologies that are available to metal finishers: (1) source reduction, (2) recycling and resource recovery, and (3) alternative treatment. The costs associated with implementing these technologies range from a few hundred dollars for making simple improvements in housekeepiing and minor process modifications to tens of thousands of dollars for installing recovery or treatment units. The benefits realized from implementing such improvements include reductions inmaterial purchase and waste disposal costs, as well as reduction in the liability

Author : Barry G. Oliver
Publisher :
Page : 76 pages
File Size : 49,74 MB
Release : 1976
Category : Heavy metals
ISBN :

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The electrochemical plating of Cu, ln, Ni and Cd from aqueous solutions has been studied using standard plate type electrodes and improved efficiencies were attained with fluidized bed electrodes. Because direct electroplating from sludge was found to be inefficient, acid and base additions were made to solubilize the metals prior to plating. Little economic advantage wou1d be gained by recovering sludge constituents, since processing costs for the large volumes of dilute leachate would be high. Therefore, the removal of heavy metals from wet sludge to reduce their toxicity does not appear to be economically feasib1e. The meta1s and phosphorus in sludge incinerator ash can be solubilized with H2S04 in a countercurrent stepwise process which uses most of the acid. Further processing of the H2S04 leachate for recovery of va1uable constituents is complicated by the presence of large quantities of iron in the leachate. Neutra1ization of the leachate with NaOH precipitates all the metals and phosphorus. Electroplating can remove Cu, ln, Ni and Cd from the ammonia, leach and ammonium phosphate can be recovered from the solution after electrolysis. While processing costs for incinerator ash are much less that those for wet sludge, the procedure does not appear to be economically viable except for very large treatment plants.