Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications
The rheological properties (yield stress, flow index and infinite dynamic viscosity) and mechanical properties (unconfined compressive strength, UCS) of different cemented paste backfill (CPB) recipes must be determined during the laboratory optimization phase. However, the influence of the mixing p...
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| Format: | Article |
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MDPI AG
2021-10-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/11/11/1159 |
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| author | Reagan Kabanga Dikonda Mamert Mbonimpa Tikou Belem |
| author_facet | Reagan Kabanga Dikonda Mamert Mbonimpa Tikou Belem |
| author_sort | Reagan Kabanga Dikonda |
| collection | DOAJ |
| description | The rheological properties (yield stress, flow index and infinite dynamic viscosity) and mechanical properties (unconfined compressive strength, UCS) of different cemented paste backfill (CPB) recipes must be determined during the laboratory optimization phase. However, the influence of the mixing procedure on these properties has scarcely been studied so far. The objective of this paper is to assess to what extent these properties depend on the specific mixing energy (SME) for a given type of mixer. CPB recipes were prepared based on two types of tailing (CPB-T1 and CPB-T2, also referred to as T1 and T2) at a fixed solid percentage for each type of tailing using the Omcan laboratory mixer. A mixture of 80% slag and 20% GU was used as a binder. The mixing time and the rotation speed of the mixer were successively varied. For each recipe prepared, we determined the SME, the rheological properties of fresh CPB (at the end of mixing) and the UCS at 7, 28 and 90 days of curing. The results show that yield stress and infinite viscosity decreased when SME increased in an interval going from 0.3 to 3.8 Wh/kg and 0.6 to 6 Wh/kg for CPB-T1 and CPB-T2, respectively. An increasing trend in UCS with increasing SME was also observed. Empirical equations describing the change of the rheological properties with the SME are used to estimate the change in rheological properties of CPB along the distribution system, considering the specific energy dissipation during CPB transportation. A mixing procedure for obtaining CPB mixtures that are representative of CPB deposited in underground mine stopes is suggested for laboratories who currently use a same mixing procedure, irrespective of the variable field specific energy. |
| first_indexed | 2024-03-10T05:14:42Z |
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| id | doaj.art-560173f7d28044749190282cc70c46f3 |
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| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T05:14:42Z |
| publishDate | 2021-10-01 |
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| series | Minerals |
| spelling | doaj.art-560173f7d28044749190282cc70c46f32023-11-23T00:31:10ZengMDPI AGMinerals2075-163X2021-10-011111115910.3390/min11111159Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical ApplicationsReagan Kabanga Dikonda0Mamert Mbonimpa1Tikou Belem2Research Institute on Mines and the Environment (RIME), Université du Québec en Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, CanadaResearch Institute on Mines and the Environment (RIME), Université du Québec en Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, CanadaResearch Institute on Mines and the Environment (RIME), Université du Québec en Abitibi-Témiscamingue (UQAT), 445 Boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, CanadaThe rheological properties (yield stress, flow index and infinite dynamic viscosity) and mechanical properties (unconfined compressive strength, UCS) of different cemented paste backfill (CPB) recipes must be determined during the laboratory optimization phase. However, the influence of the mixing procedure on these properties has scarcely been studied so far. The objective of this paper is to assess to what extent these properties depend on the specific mixing energy (SME) for a given type of mixer. CPB recipes were prepared based on two types of tailing (CPB-T1 and CPB-T2, also referred to as T1 and T2) at a fixed solid percentage for each type of tailing using the Omcan laboratory mixer. A mixture of 80% slag and 20% GU was used as a binder. The mixing time and the rotation speed of the mixer were successively varied. For each recipe prepared, we determined the SME, the rheological properties of fresh CPB (at the end of mixing) and the UCS at 7, 28 and 90 days of curing. The results show that yield stress and infinite viscosity decreased when SME increased in an interval going from 0.3 to 3.8 Wh/kg and 0.6 to 6 Wh/kg for CPB-T1 and CPB-T2, respectively. An increasing trend in UCS with increasing SME was also observed. Empirical equations describing the change of the rheological properties with the SME are used to estimate the change in rheological properties of CPB along the distribution system, considering the specific energy dissipation during CPB transportation. A mixing procedure for obtaining CPB mixtures that are representative of CPB deposited in underground mine stopes is suggested for laboratories who currently use a same mixing procedure, irrespective of the variable field specific energy.https://www.mdpi.com/2075-163X/11/11/1159cemented paste backfill (CPB)CPB formulationspecific mixing energyrheological propertiesUCSenergy dissipation during CPB transportation |
| spellingShingle | Reagan Kabanga Dikonda Mamert Mbonimpa Tikou Belem Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications Minerals cemented paste backfill (CPB) CPB formulation specific mixing energy rheological properties UCS energy dissipation during CPB transportation |
| title | Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications |
| title_full | Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications |
| title_fullStr | Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications |
| title_full_unstemmed | Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications |
| title_short | Specific Mixing Energy of Cemented Paste Backfill, Part II: Influence on the Rheological and Mechanical Properties and Practical Applications |
| title_sort | specific mixing energy of cemented paste backfill part ii influence on the rheological and mechanical properties and practical applications |
| topic | cemented paste backfill (CPB) CPB formulation specific mixing energy rheological properties UCS energy dissipation during CPB transportation |
| url | https://www.mdpi.com/2075-163X/11/11/1159 |
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