Development of Membranes Based on Alkali-Activated Phosphate Mine Tailings for Humic Acid and Copper Removal from Water

Mine tailings (MT) could represent a step forward in terms of the quality of the aggregates usually used in civil engineering applications, mostly due to its high density. The Portuguese Neves Corvo copper mine, owned by the Lundin Mining Corporation, produces approximately 3 million tonnes per year. Nevertheless, it cannot be used in its original state, due to its high levels of sulphur and other metals (As, Cr, Cu, Pb, Zn). This paper focuses on the stabilisation/solidification of high-sulphur MT, without any previous thermal treatment, using alkali-activated fly ash (FA). The variables considered were the MT/FA ratio and the activator type and concentration. A fine aggregate was then added to the pastes to assess the quality of the resulting mortar. Maximum compressive strengths of 14 MPa and 24 MPa were obtained for the pastes and mortars, respectively, after curing for 24 h at 85 °C. Thermogravimetric analysis, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction, and infrared spectroscopy were used to characterize the reaction products, and two types of leaching tests were performed to assess the environmental performance. The results showed that the strength increase is related with the formation of a N-A-S-H gel, although sodium sulphate carbonate was also developed, suggesting that the total sodium intake could be optimized without strength loss. The solubility of the analysed metals in the paste with 78% MT and 22% FA was below the threshold for non-hazardous waste.

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Utilizing phosphate mine tailings to produce ceramisite

Construction and Building Materials ◽

10.1016/j.conbuildmat.2017.08.070 ◽

2017 ◽

Vol 155 ◽

pp. 1081-1090 ◽

Cited By ~ 11

Author(s):

Yonghao Yang ◽

Zuoan Wei ◽

Yu-long Chen ◽

Yunju Li ◽

Xiaoyan Li

Keyword(s):

Mine Tailings ◽

Phosphate Mine

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Enhanced mobilization of arsenic and heavy metals from mine tailings by humic acid

Chemosphere ◽

10.1016/j.chemosphere.2008.09.040 ◽

2009 ◽

Vol 74 (2) ◽

pp. 274-279 ◽

Cited By ~ 95

Author(s):

Suiling Wang ◽

Catherine N. Mulligan

Keyword(s):

Heavy Metals ◽

Humic Acid ◽

Mine Tailings

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XRD and TG-DTA Study of New Phosphate-Based Geopolymers with Coal Ash or Metakaolin as Aluminosilicate Source and Mine Tailings Addition

Materials ◽

10.3390/ma15010202 ◽

2021 ◽

Vol 15 (1) ◽

pp. 202

Author(s):

Dumitru Doru Burduhos Nergis ◽

Petrica Vizureanu ◽

Andrei Victor Sandu ◽

Diana Petronela Burduhos Nergis ◽

Costica Bejinariu

Keyword(s):

Mine Tailings ◽

Room Temperature ◽

Raw Materials ◽

Coal Ash ◽

Water Evaporation ◽

Oxidation Reactions ◽

X Ray Diffraction ◽

Xrd Patterns ◽

First Time ◽

Alkali Activated

Coal ash-based geopolymers with mine tailings addition activated with phosphate acid were synthesized for the first time at room temperature. In addition, three types of aluminosilicate sources were used as single raw materials or in a 1/1 wt. ratio to obtain five types of geopolymers activated with H3PO4. The thermal behaviour of the obtained geopolymers was studied between room temperature and 600 °C by Thermogravimetry-Differential Thermal Analysis (TG-DTA) and the phase composition after 28 days of curing at room temperature was analysed by X-ray diffraction (XRD). During heating, the acid-activated geopolymers exhibited similar behaviour to alkali-activated geopolymers. All of the samples showed endothermic peaks up to 300 °C due to water evaporation, while the samples with mine tailings showed two significant exothermic peaks above 400 °C due to oxidation reactions. The phase analysis confirmed the dissolution of the aluminosilicate sources in the presence of H3PO4 by significant changes in the XRD patterns of the raw materials and by the broadening of the peaks because of typically amorphous silicophosphate (Si–P), aluminophosphate (Al–P) or silico-alumino-phosphate (Si–Al–P) formation. The phases resulted from geopolymerisation are berlinite (AlPO4), brushite (CaHPO4∙2H2O), anhydrite (CaSO4) or ettringite as AFt and AFm phases.

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Compressive Strength Characteristics of Cemented Tailings Backfill with Alkali-Activated Slag

Applied Sciences ◽

10.3390/app8091537 ◽

2018 ◽

Vol 8 (9) ◽

pp. 1537 ◽

Cited By ~ 41

Author(s):

Gaili Xue ◽

Erol Yilmaz ◽

Weidong Song ◽

Shuai Cao

Keyword(s):

Compressive Strength ◽

Mine Tailings ◽

Low Cost ◽

Cementitious Materials ◽

Cementitious Material ◽

Solid Wastes ◽

Fine Grained ◽

Activated Slag ◽

The Relationship ◽

Alkali Activated

With the use of glauberite mineral (GM) and sodium hydroxide (SH) alkaline catalysts to stimulate slag powder’s internal cementation activity and incorporate the two fine-grained solid wastes, such as quicklime (Q) and desulfurized ash (DA), a new cementitious material suitable for mine tailings was developed to replace traditional ordinary Portland cement (OPC) for reducing cement-related costs. A series of uniaxial compressive strength (UCS) tests were carried out on cemented tailings backfill (CTB) samples containing different activators. The results showed that (1) the highest UCS values of 14-day and 28-day cured CTB samples were 1.259 MPa and 2.429 MPa, respectively, and the effect of different activator types was in the order of SH > GM > DA > Q and SH > GM > Q > DA; (2) the relationship between UCS and activator dosages followed the function y = ax3 − bx2 + cx − d. Compared with the OPC 32.5 R cemented samples, the minimum strength growth factor was 1.45, and the maximum reached 2.03; (3) the optimal proportion of DA slag formula was 4.5% or 5.0% Q, 19% DA, 2.5% GM, and 0.7% SH. The aforesaid new cementitious materials met the mine’s UCS requirements with a relatively low cost (17.04–17.20 €/ton) and solved the stacking problem of solid wastes on the surface well. Ultimately, this study provides a useful reference for the development of mineral binders.

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Phosphate Mine Tailing Recycling in Membrane Filter Manufacturing: Microstructure and Filtration Suitability

Minerals ◽

10.3390/min9050318 ◽

2019 ◽

Vol 9 (5) ◽

pp. 318 ◽

Cited By ~ 6

Author(s):

Mohamed Loutou ◽

Wafa Misrar ◽

Mohammed Koudad ◽

Mohammed Mansori ◽

Liga Grase ◽

...

Keyword(s):

Mine Tailings ◽

Textile Industry ◽

Ceramic Membrane ◽

Membrane Filter ◽

Mercury Porosimetry ◽

Industrial Effluent ◽

Ceramic Membranes ◽

Effluent Treatment ◽

Membrane Filters ◽

Phosphate Mine

Ceramic membrane filters based on industrial by-products can be considered to be a valorization alternative of phosphate mine tailings, even more so if these ceramic membranes are used in the industrial wastewater treatment due to their good mechanical, chemical, and thermal resistance. The depollution of textile industry rejections with this method has not been studied in detail previously. In this work, ceramic membrane filters have been manufactured from natural clay and phosphate mine tailings (phosphate sludge). Blends of the abovementioned materials with a pore-forming agent (sawdust, up to 20 wt. %) were investigated in the range 900–1100 °C using thermal analysis, X-ray diffraction, scanning electron microscopy, and mercury porosimetry. Ceramic properties were measured as a function of firing temperature and sawdust addition. Filtration tests were carried out on samples with advantageous properties. The results showed that gehlenite together with diopside neoformed from lime decomposed carbonates and breakdown products of clay minerals, while calcium phosphate derived from partial decomposition of fluorapatite. Both quartz and fluorapatite resisted heating. The results of the experimental design showed that the variations of physical properties versus processing factors were well described by the polynomial model. Filtration results are quite interesting, allowing these membranes to be used in industrial effluent treatment.

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