Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions
The main purpose of this study was to characterize the mineral and chemical composition of typical red muds in China. Changes in the physicochemical and microstructural properties of red muds collected from the Shanxi and Shandong provinces were investigated after they were immersed in an alkaline N...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-04-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/10/9/2993 |
| _version_ | 1797569613249118208 |
|---|---|
| author | Qingke Nie Youdong Li Guohui Wang Bing Bai |
| author_facet | Qingke Nie Youdong Li Guohui Wang Bing Bai |
| author_sort | Qingke Nie |
| collection | DOAJ |
| description | The main purpose of this study was to characterize the mineral and chemical composition of typical red muds in China. Changes in the physicochemical and microstructural properties of red muds collected from the Shanxi and Shandong provinces were investigated after they were immersed in an alkaline NaOH or an acidic HCl solution for 7, 28, and 120 days. The results showed that red mud has a high cation exchange capacity and active physicochemical properties, which can be closely related to its extremely high alkalinity and complex microstructure. The neutralization of red mud with the HCl solution results in the release of Na<sup>+</sup> from the red mud particles into the leachate and can effectively decrease the pH value of the filtrate. The neutralization process can result in a significant decrease in the liquid limit, plastic limit and plasticity index, whereas the opposite was observed for the different parameters after the addition of the NaOH solution. In this sense, acid neutralization can significantly improve the cementation property of the red mud. This result will increase the water permeability of the acid-treated soil layer and improve the growth ability of plants. The specific surface area of red mud immersed in the NaOH solution decreased, whereas the specific surface area of red mud immersed in the HCl solution increased. This study contributes to our understanding of red mud properties after the red mud has been subjected to acidic and alkaline treatments, and the results can provide insights into the safe disposal of red mud. |
| first_indexed | 2024-03-10T20:13:28Z |
| format | Article |
| id | doaj.art-083a798bc32445ed9ac818d002fa4c0f |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T20:13:28Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-083a798bc32445ed9ac818d002fa4c0f2023-11-19T22:43:51ZengMDPI AGApplied Sciences2076-34172020-04-01109299310.3390/app10092993Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline ConditionsQingke Nie0Youdong Li1Guohui Wang2Bing Bai3Hebei Research Institute of Construction and Geotechnical Investigation Co. Ltd., Shijiazhuang 050031, ChinaHebei Research Institute of Construction and Geotechnical Investigation Co. Ltd., Shijiazhuang 050031, ChinaHebei Research Institute of Construction and Geotechnical Investigation Co. Ltd., Shijiazhuang 050031, ChinaSchool of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaThe main purpose of this study was to characterize the mineral and chemical composition of typical red muds in China. Changes in the physicochemical and microstructural properties of red muds collected from the Shanxi and Shandong provinces were investigated after they were immersed in an alkaline NaOH or an acidic HCl solution for 7, 28, and 120 days. The results showed that red mud has a high cation exchange capacity and active physicochemical properties, which can be closely related to its extremely high alkalinity and complex microstructure. The neutralization of red mud with the HCl solution results in the release of Na<sup>+</sup> from the red mud particles into the leachate and can effectively decrease the pH value of the filtrate. The neutralization process can result in a significant decrease in the liquid limit, plastic limit and plasticity index, whereas the opposite was observed for the different parameters after the addition of the NaOH solution. In this sense, acid neutralization can significantly improve the cementation property of the red mud. This result will increase the water permeability of the acid-treated soil layer and improve the growth ability of plants. The specific surface area of red mud immersed in the NaOH solution decreased, whereas the specific surface area of red mud immersed in the HCl solution increased. This study contributes to our understanding of red mud properties after the red mud has been subjected to acidic and alkaline treatments, and the results can provide insights into the safe disposal of red mud.https://www.mdpi.com/2076-3417/10/9/2993red mudfiltratephysicochemical propertyspecific surface areamicrostructure |
| spellingShingle | Qingke Nie Youdong Li Guohui Wang Bing Bai Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions Applied Sciences red mud filtrate physicochemical property specific surface area microstructure |
| title | Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions |
| title_full | Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions |
| title_fullStr | Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions |
| title_full_unstemmed | Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions |
| title_short | Physicochemical and Microstructural Properties of Red Muds under Acidic and Alkaline Conditions |
| title_sort | physicochemical and microstructural properties of red muds under acidic and alkaline conditions |
| topic | red mud filtrate physicochemical property specific surface area microstructure |
| url | https://www.mdpi.com/2076-3417/10/9/2993 |
| work_keys_str_mv | AT qingkenie physicochemicalandmicrostructuralpropertiesofredmudsunderacidicandalkalineconditions AT youdongli physicochemicalandmicrostructuralpropertiesofredmudsunderacidicandalkalineconditions AT guohuiwang physicochemicalandmicrostructuralpropertiesofredmudsunderacidicandalkalineconditions AT bingbai physicochemicalandmicrostructuralpropertiesofredmudsunderacidicandalkalineconditions |