Use of clay-containing waste as pozzolanic additives
Growing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiolog...
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| Format: | Article |
| Language: | English |
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Saint-Petersburg Mining University
2023-04-01
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| Series: | Записки Горного института |
| Subjects: | |
| Online Access: | https://pmi.spmi.ru/index.php/pmi/article/view/16028?setLocale=en_US |
| _version_ | 1797826161551605760 |
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| author | Andrei M. Gerasimov Ivan D. Ustinov Olga V. Zyryanova |
| author_facet | Andrei M. Gerasimov Ivan D. Ustinov Olga V. Zyryanova |
| author_sort | Andrei M. Gerasimov |
| collection | DOAJ |
| description | Growing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiological safety of population. The article presents a possibility of recycling one type of such waste (clay-containing concentration tailings of apatite-nepheline and sylvinite ores, coal beneficiation tailings) by using them after preliminary thermochemical treatment as pozzolanic additives to cements and concretes, including concrete mixtures used for soil stabilization, development of territories, reclamation of mine workings, as a component of the insulating layer of landfills for the disposal of municipal solid waste. An analysis of the phase changes of kaolinite, one of the main minerals that make up clay-containing waste, in the temperature range of 200-1,000 °С showed that a change in its mineral form during heat treatment is the main factor in changing its pozzolanic activity. The effect of heat treatment of clay minerals at temperature of 700-800 °C on their pozzolanic activity, estimated by the ability to absorb calcium hydroxide (0.7 g Ca(OH)2 per 1 g of modified kaolinite), is considered. It is shown that the addition of heat-treated samples (20 % by weight) improves the quality of cement increasing its activity by 15 %, in comparison with the use of unmodified clay minerals. It was proved experimentally that partial replacement of Portland cement with thermally modified kaolinite increases the strength of consolidating stowing mixture by up to 15 %. This approach to processing of ores containing layered silicates, which provides for thermochemical modification of run-of-mine ore, intensifies the processes of tailings thickening and
filtering. |
| first_indexed | 2024-03-13T11:04:37Z |
| format | Article |
| id | doaj.art-a19ed0b97433473baae45e7112ce762e |
| institution | Directory Open Access Journal |
| issn | 2411-3336 2541-9404 |
| language | English |
| last_indexed | 2024-03-13T11:04:37Z |
| publishDate | 2023-04-01 |
| publisher | Saint-Petersburg Mining University |
| record_format | Article |
| series | Записки Горного института |
| spelling | doaj.art-a19ed0b97433473baae45e7112ce762e2023-05-16T11:30:17ZengSaint-Petersburg Mining UniversityЗаписки Горного института2411-33362541-94042023-04-0126031332010.31897/PMI.2023.3316028Use of clay-containing waste as pozzolanic additivesAndrei M. Gerasimov0https://orcid.org/0000-0002-2197-6200Ivan D. Ustinov1https://orcid.org/0000-0003-3328-8621Olga V. Zyryanova2https://orcid.org/0000-0001-7866-8543Saint Petersburg Mining UniversityNPK “Mekhanobr-tekhnika” (AO)Saint Petersburg Mining UniversityGrowing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiological safety of population. The article presents a possibility of recycling one type of such waste (clay-containing concentration tailings of apatite-nepheline and sylvinite ores, coal beneficiation tailings) by using them after preliminary thermochemical treatment as pozzolanic additives to cements and concretes, including concrete mixtures used for soil stabilization, development of territories, reclamation of mine workings, as a component of the insulating layer of landfills for the disposal of municipal solid waste. An analysis of the phase changes of kaolinite, one of the main minerals that make up clay-containing waste, in the temperature range of 200-1,000 °С showed that a change in its mineral form during heat treatment is the main factor in changing its pozzolanic activity. The effect of heat treatment of clay minerals at temperature of 700-800 °C on their pozzolanic activity, estimated by the ability to absorb calcium hydroxide (0.7 g Ca(OH)2 per 1 g of modified kaolinite), is considered. It is shown that the addition of heat-treated samples (20 % by weight) improves the quality of cement increasing its activity by 15 %, in comparison with the use of unmodified clay minerals. It was proved experimentally that partial replacement of Portland cement with thermally modified kaolinite increases the strength of consolidating stowing mixture by up to 15 %. This approach to processing of ores containing layered silicates, which provides for thermochemical modification of run-of-mine ore, intensifies the processes of tailings thickening and filtering.https://pmi.spmi.ru/index.php/pmi/article/view/16028?setLocale=en_USclay-containing wastepozzolanic additivespozzolanic activityheat treatmentkaolinitemetakaolinstowing mixtures |
| spellingShingle | Andrei M. Gerasimov Ivan D. Ustinov Olga V. Zyryanova Use of clay-containing waste as pozzolanic additives Записки Горного института clay-containing waste pozzolanic additives pozzolanic activity heat treatment kaolinite metakaolin stowing mixtures |
| title | Use of clay-containing waste as pozzolanic additives |
| title_full | Use of clay-containing waste as pozzolanic additives |
| title_fullStr | Use of clay-containing waste as pozzolanic additives |
| title_full_unstemmed | Use of clay-containing waste as pozzolanic additives |
| title_short | Use of clay-containing waste as pozzolanic additives |
| title_sort | use of clay containing waste as pozzolanic additives |
| topic | clay-containing waste pozzolanic additives pozzolanic activity heat treatment kaolinite metakaolin stowing mixtures |
| url | https://pmi.spmi.ru/index.php/pmi/article/view/16028?setLocale=en_US |
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