| 1. |
- Macsik, Josef, et al.
(författare)
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Leachability of V and Cr from LD-Slag/Portland cement stabilised sulphide soil
- 1996
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Ingår i: Waste Management. - 0956-053X .- 1879-2456. ; 16:8, s. 699-709
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to improve the mechanical stability of a sulphide soil with additives of an industrial waste product (LD-Slag) and Portland Cement. The criterion of using LD-Slag was if it could be done in an environmentally proper way. Sequential Leaching Tests were performed on monolithic LD-Slag/Portland Cement stabilised sulphide soil samples in order to register the leachability and pollution potentials. Different pH and Eh conditions were established in these tests in order to control the leachability of Na, K, Ca and Mg, which are important during cementation processes inside as well as outside an inforced monolith, and the leachability of V, which is regarded as a pollutant. The contents of Cr and V of pure LD-Slag, monolithic samples and leachates were compared with Canadian and Finnish Maximum Containment Level standards. The investigation showed that acidic conditions will increase the leachability of V. An acidic environment will even change the physical properties of a monolith. However, acidic conditions are not likely to occur in an in-situ anaerobic sulphide soil.
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| 2. |
- Singh, Maneesh, et al.
(författare)
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Preparation of special cements from red mud
- 1996
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Ingår i: Waste Management. - 0956-053X .- 1879-2456. ; 16:8, s. 665-670
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Tidskriftsartikel (refereegranskat)abstract
- Red mud from HINDALCO (Hindustan Aluminium Corporation) Industries Limited, Renukoot, India, contains significant quantities of alumina, iron oxide and silica. Presence of the said constituents makes it a suitable ingredient for the preparation of special cements. Preparation of three varieties of cements was investigated, namely: (a) aluminoferrite (C4AF)- belite (β-C2S) using lime + red mud + fly ash; (b) aluminoferrite-ferrite (C2F)-aluminates (C3A and C12A7) utilising lime + red mud + bauxite; and (c) sulfoaluminate (C4A3S̄)-aluminoferrite-ferrite using lime + red mud + bauxite + gypsum. The effects of composition (proportions of lime, red mud, fly ash, bauxite and gypsum), firing temperature and duration on the properties of cements produced were studied in detail. Cements made from lime + red mud + bauxite or lime + red mud + bauxite + gypsum exhibit strengths comparable or superior to ordinary Portland cement (OPC). On the other hand, those prepared using lime + red mud + fly ash did not have sufficient strength. Moreover, it was not possible to replace bauxite by fly ash (as a source of alumina) in any significant quantity.
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| 3. |
- Lin, ZX, et al.
(författare)
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Predicting the mobility of Zn, Fe, Cu, Pb, Cd from roasted sulfide (pyrite) residues - A case study of wastes from the sulfuric acid industry in Sweden
- 1996
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Ingår i: WASTE MANAGEMENT. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0956-053X. ; 16:8, s. 671-681
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Tidskriftsartikel (refereegranskat)abstract
- Leachates from roasted sulfide residues, which are the wastes from the production of sulfuric acid at Falun, Sweden, have low pH and high concentrations of Zn, Fe, and SO4. The minerals are mainly hematite and maghemite and, because the various sulfides i
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