Factors influencing chromium recovery from chromium sulphate tanned leather scrap ashes / S. Carneiro in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 1 (01-02/2003)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 87, N° 1 (01-02/2003) . - p. 1-10 Titre : Factors influencing chromium recovery from chromium sulphate tanned leather scrap ashes Type de document : texte imprimé Auteurs : S. Carneiro, Auteur ; M. F. Almeida, Auteur ; M. F. Ferreira, Auteur Année de publication : 2003 Article en page(s) : p. 1-10 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cendres -- Teneur en chrome Chrome -- Recyclage Cuirs et peaux Déchets industriels -- Recyclage Incinération Tannage -- Déchets Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Basic chromium salt is the main tanning reagent used all over the world and it represents one of the most important applications of chromium salts. When leather scrap tanned with chromium sulphate is burned, the respective ashes contain meaningful amounts of chromium, some of it in the hexavalent form. This paper presents some efforts aimed at using the ashes from a fixed grate incinerator (FGI) as a source of chromium for various applications. Two types of ashes were characterised. Several tests with mixtures of alkaline and alkaline earth fluxes followed by hot washing the product were carried out to recover chromium from the ashes. The factors influencing chromium recovery were screened through an experimental design approach and hypothesis testing. Using ashes as pigment for ceramic glazes was also evaluated. Note de contenu : - CHARACTERISATION OF ASHES AND EXPERIMETNAL PROCEDURES : Principles of the experimental process - RESULTS AND DISCUSSION : First set of experiments - Second set of experiments - Third set of experiments - Fourth set of experiments - Table 1 : Experiments carried out at 750°C with NA2CO3 based mixtures and respective Cr recoveries - Table 2 : Experiments carried out at 350, 450 and 550°C with mixtures based on NaOH - Table 3 : Cr recoveries at 350, 450 and 550°C with mixtures based on NaOH - Table 4 : Experiments carried out at 350, 450 and 550°C with mixtures based on NaOH and NaNO3 En ligne : https://drive.google.com/file/d/19Zv2OsYHHMm0WjcPxW4ash70Z_iVjqG8/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39804 [article]

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Using ashes from incineration of chromium sulphate tanned leather scrap - Part 1 : Characterization of ashes and chromium extraction in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 84, N° 6 (11-12/2000)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 84, N° 6 (11-12/2000) . - p. 271-275 Titre : Using ashes from incineration of chromium sulphate tanned leather scrap - Part 1 : Characterization of ashes and chromium extraction Type de document : texte imprimé Année de publication : 2000 Article en page(s) : p. 271-275 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation Cendres -- Teneur en chrome Chrome hexavalent Cuirs et peaux -- Déchets -- Recyclage Extraction (chimie) Incinération Récupération (Déchets, etc.) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Chromium is the basis of leather manufacture and its extractable reserves are limited in distribution, mainly in South Africa, Zimbabwe and ex-USSR countries. Almost 20% of the metal is used by the chemical industry where one third of it goes into leather production as chromium sulphate tanning agent. The European Union depends on chromium imports. After burning leather scrap—tanned with chromium sulphate-the resulting very rich chromium ashes may present chromium (VI) in such a concentration that it becomes a hazardous waste and needs careful handling. Thus, both economic and environmental reasons suggest the use of these ashes. This paper mainly summarizes some of the conclusions of the research carried out during the execution of CRAFT project BRST-CT96-5085, where leather incineration ashes generated by two different pilot combustion systems, respectively a fixed grill incinerator (FGI) and a fluidized bed incinerator (FBI) were characterized and chromium was leached using a mixed pyrometallurgical and hydrometallurgical route as well as a full hydrometallurgical route. Note de contenu : - EXPERIMENTAL PROCEDURES : Methods and procedure - RESULTS AND DISCUSSION : Characteristics of ashes - Chromium extraction from ashes by a hydrometallurgical route - Chromium extraction from ashes by a pyrometallurgical and hydrometallurgical route - Silica leaching from the ashes - Table 1 : XRF results of the FGI and FBI ash analyses - Table 2 : Influence of acid concentration, grinding, temperature and time on chromium recovered from FGI ashes En ligne : https://drive.google.com/file/d/1CbRiDpse_L8eNNFYuP0Qvf6_lsRNlsmM/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40818 [article]

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