Microsoft Word - ETASR_V13_N1_pp10005-10013 Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10005 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... Geotechnical Characterization of Phosphate Mining Waste Materials for Use in Pavement Construction RachidaMalaoui Environmental Laboratory, Civil Engineering Dpt, Echahid Cheikh Larbi Tebessi University, Algeria rachida.malaoui@univ-tebessa.dz (corresponding author) El Haddi Harkati Mining Laboratory, Civil Engineering Dpt, Echahid Cheikh Larbi Tebessi University, Algeria harkati.elhaddi@gmail.com Mohamed Redha Soltani Mining Laboratory, Civil Engineering Dpt, Echahid Cheikh Larbi Tebessi University, Algeria msoltani.mohamedredha@univ-tebessa.dz Adel Djellali Environmental Laboratory, Civil Engineering Dpt, Echahid Cheikh Larbi Tebessi University, Algeria adel.djellali@univ-tebessa.dz Abderraouf Soukeur Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, University of Science and Technology Houari Boumediene, Algeria abderraoufsoukeur@gmail.com Rabah Kechiched Underground Reservoirs Laboratory: Oil, Gas, and Aquifers, Kasdi Merbah Ouargla University, Algeria rabeh21@yahoo.fr Received: 16 November 2022 | Revised: 7 December 2022 | Accepted: 9 December 2022 ABSTRACT Waste rock materials are becoming widely used in road pavement and building constructions in many countries. In this work, experimental laboratory tests were carried out on the waste rock produced from the extraction of the phosphate in the Kef-Essenoun mine, to study the performance of road pavement foundations built with these types of material. Two types of waste, namely phosphatic limestone (type 1) and limestone (type 2), were initially tested to determine the most suitable one to be used in pavement structures. The characterization tests showed that the presence of carbonate-fluorapatite and carbonate- fluorapatite, and calcite, dolomite, and quartz are predominant in phosphatic limestone and limestone, respectively. The Los Angeles Abrasion (LA) and Micro-Deval (MD) values range from 59.9% to 90.4% and 42.05% to 86.31% for phosphatic limestone and from 43.64% to 95.88% and 38.25% to 75% for limestone. The CBR values of type 1 and type 2 waste were found to be 10.5% and 18.7% respectively. The results show that these materials, classified as B42ts and B42s respectively, could be used cautiously in capping layers and pavement backfilling materials. Furthermore, they must be treated with a hydraulic binder such as cement in order to improve their physical and mechanical properties. Keywords-characterization; mine waste; phosphatic limestone; limestone; road construction; Kef-Essenoun Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10006 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... I. INTRODUCTION Road infrastructure projects require large quantities of materials. The growing demand for aggregates in the civil construction sector has become more pronounced in recent years as cities grow more and more. The use of unusual industrial mining products in road construction can contribute to the conservation of non-renewable natural resources and minimize the waste quantities produced by mining industries [1]. Such large amounts of waste, resulting from mining operations, have led to the awareness regarding their impact on environment, ecology, and geotechnical side. The release of toxic components from heavy metals and acid mine drainage are examples of such effects. Underground water contamination, large amounts of space of exploitable natural land, instability of the waste storage zone, and dust cloud generation are some examples of such effects. There are numerous economic and ecological gains in the exploitation of alternative materials for the road construction sector. When waste materials with adequate properties are used, it is possible to reduce energy consumption, transport distances, and extraction costs [2]. For several decades the reuse of waste materials as construction materials has been studied in depth, e.g. mine tailings [1-3], recycled construction and demolition wastes used in road construction, embankments and concrete [4-7], coal mining waste [8-9], plastic and rubber waste in flexible and rigid pavements, ferrocement mortar [10-12], steel slag and glass as secondary aggregates in asphalt mixtures [13- 15], tungsten mining waste [16], marine sediments [17], bottom ash and fly ash in geotechnical engineering [18], iron and gold mining waste [19], and red mud and lime [20]. In addition, pozzolanic materials such as cement, lime, fly ash, cement kiln dust, and ordinary Portland cement have been used to stabilize some tailings materials for construction purposes [21-23]. Algeria has a large reserve of phosphate [24]. About 41ha of land are currently under exploitation in Kef-Essenoun. The current removal mining rate is 2.8 million tons of ore with a stripping ratio of approximately 2.2 which produces annually 10 million tons of waste that must be removed and disposed of. The accumulation for several decades of waste rock from open- pit phosphate mines and upgrading processes poses serious environmental, ecological, and health problems in the surrounding areas [25]. These types of waste are unsafe to humans, animals, and vegetation. They pollute the air, the surrounding soil, and contaminate the groundwater. The main objective of this research consists in suggesting a reusing solution in order to reduce the negative impact of rock waste on the environment. Reusing consists of finding a new use for available waste materials with adequate acceptable properties in their current form in order to ovoid disposal on landfills. As reported in [26-31], those materials (phosphate tailings) could be widely used in building and road construction. The proposed reusing approach should be integrated in the Algerian road guide. It is worth noting that studies on phosphate mining waste in Algeria are rare, thus, chemical, mineralogical, physical, and geotechnical characterizations of mining waste from Kef-Essenoun phosphate mine were investigated in this study. II. GENERAL SETTING The Kef-Essenoun phosphate mine (34.726784 E, 7.895978 N) is located on the southern flank of Djebel Onk cretaceous anticline in the Eastern Saharan Atlas [32]. It is situated 7km southeast of Bir El Ater City (Tebessa, northeast Algeria) and about 21km to the Algerian-Tunisian border [33]. The study site extends approximately to 250ha and belongs to the Djebel Onk mining basin which represents the occidental part of Gafsa-Metaloui-Onk basin containing many phosphorite layers deposited from late Cretaceous to early Eocene [32-34]. Although this lateral continuity, the Kef- Essenoun deposit displays substantial differences to the Gafsa Metlaoui basin, especially with regard to the lithology and the succession particularly in the phosphorite formation [35-36]. In the Kef- Essenoun deposit, the sedimentary lithologies consist of ~ 500m thick succession of upper Cretaceous (Maastrichtian) to middle Eocene (Lutetian) age where upper thanetian phosphorite layer is mined for phosphate raw material [32-37]. Mine waste rock from Kef-Essenoun mine (Figure 1) consists of soil and rock excavated during the mining operations after the commercially recoverable part has been recovered. These waste rocks are unloaded and accumulated in huge quantities. Between 2006 and 2017, the estimated quantity of waste rock produced is approximately 5.5 to 18.5Mt/yr. This quantity will increase to more than 18Mt/yr in the future (Figure 2). Fig. 1. Phosphate mine waste hips nearby the mining site. Fig. 2. Estimated quantities of waste rock from Kef-Essenoun [38]. Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10007 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... Fig. 3. Tailings of Kef Essenoun mine: (a) phosphatic limestone, (b) limestone. Those amounts of waste can be utilized in the field of pavement construction. The reuse of mine tailings for subgrade and foundation layers is a relatively new approach in Algeria. The lack of fundamental knowledge about their behavior limits their reuse. Therefore, and in order to examine the various aspects concerning the possibility of using this mining waste in road engineering, complete characterization is necessary. The objective of this experimental study is to make a geotechnical characterization of the two recycled mining materials of Kef- Essenoun. In this research, the studied materials are phosphatic limestone (type 1) and limestone (type 2) (Figure 3). III. EXPERIMENTAL PROGRAM AND TEST PROCEDURES A. Initial Testing and Study Material Selection The mining waste samples used in this research were collected from different locations of stacked tailings located in the surroundings of the Kef-Essenoun mine. The waste consists mainly of phosphatic limestone and limestone. These materials were brined to the laboratory in order to describe their mineralogical, chemical, physical, and mechanical properties. B. Chemical and Mineralogical Characteristics The analysis of the major elements was conducted by the Algerian phosphate company SOMIPHOS using colorimetric, gravimetric, volumetric, ionometric, and spectrophotometric by Atomic Absorption Spectrometry (AAS) analytical methods. The phosphate ore tailings of crystalline phases were performed by X-Ray Diffraction, (XRD). Diffraction patterns were made with a PANalytical X’Pert Pro diffractometer equipped with a conventional X-ray (Cu Kα radiation, running at 40kV and 30mA) with detection in the 2θ range of 10-90°. C. Physical and Mechanical Parameters of Waste Materials The main physical and mechanical characteristics of the studied waste samples are shown in Table I. Using oven drying at 105°C (+/- 5°C), the measured initial water content was about 4.62% and 8.54% for phosphatic limestone and limestone, respectively (NF P94-050). The following parameters were measured:  Specific gravity was measured with a NF P94-054 Pycnometer.  Clay fraction activity was measured by methylene blue test (NF P 94-068).  Liquid and plastic limits (NF P94-051).  Particle size distribution was measured according to NF P 94-056.  Modified proctor (NF-P 94-093).  California bearing capacity (NF-P94-078).  Los Angeles, micro-deval, and friability (P 18-573, P 18- 572, P18-576).  Unconfined compressive strength procedure NF P98-230-3. The test particle size consists of a representative sample of soil passing through superposed sieves with openings from 50mm to 0.08mm. Figure 4 shows the particle size distribution curves of the samples. The samples were classified according to the modified LPC classification system. According to the particle size curve, the percentages of cobbles, gravel, sand, silt, and clay in phosphatic limestone and limestone were 51%, 29%, 17.28%, and 2.72%, and 27.5%,29%, 40.23%, and 3.27%, respectively. The coefficients of uniformity (Cu) and curvature (Cc) obtained for phosphatic limestone and limestone were 69.44, 17.85, and 0.36, 4.11, respectively. Based on the unified soil classification system, both sample types were classified as well-graded gravel (Gm). The particle size distribution and gradation characteristics of the tested samples are shown in Table I. Fig. 4. Particle size distribution curves of phosphatic limestone and limestone waste. D. Soil Classification Based on the technical guidelines of embankment and capping layer construction (GTR), the tailing materials belong to the B Class of sand and gravel soils with fines. Depending on the nature of these materials, their class is B4. They have a passing percentage less than 12% and less than 70% from the of 80μm and 2mm sieves, respectively. There is no grain-size over 50mm. The methyl blue absorption value is more than 0.2. MD coefficient and LA coefficient are greater than 45. These types of materials are sensitive to water due to the existence of plastic fines and contain a large proportion of coarse particles, so they are generally pervious. The waste materials are classified as: B42ts (very dry) for type 1 and B42s (dry) for type 2 as can be shown in Figure 5. Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10008 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... TABLE I. PHYSICO-MECHNICAL PARAMETERS OF WASTE MATERIALS Properties of mine railing Unit Type1 Type2 Moisture content % 4.62 8.54 PH 6.8 7.8 Geotechnical properties—Natural parameters Grain - size distribution Color Grayish Beige Shape Angular Angular Particle size distribution Silt and clay % 2.78 3.27 Sand 17.28 40.23 Gravel 29.00 29.00 Cobbles 51.00 27.50 Coefficient of uniformity (CU = D60/D10) 69.44 17.85 Coefficient of gradation 0.36 4.11 Cc = (D30)2/(D10 × D60) Group symbol LPC Gm Gm Optimum Moisture content (Wopt) 12.30 14.15 Maximum dry density dmax kN/m 3 1.85 2.00 Unsoaked CBR % 24.724 36.675 Soaked CBR 10.548 18.293 Free swelling 0.303 0.308 Liquid limit (LL) 30.88 33.41 Plastic limit (PL) Not measured 23.805 Plasticity index (PI) - 9.6 Methylene blue value (MBV) g/100g 0.83 1 Carbonate content % 54 88 Organic matter < 1 < 1 Sand Equivalent (SE) 22.22 12.82 Specific gravity kN/m3 2.737 2.631 Apparent specific gravity 1.434 1.328 Los Angeles abrasion test 4/6.3 6.3/10 10/14 % % 82.9 75.5 72.2 95.88 59.36 43.64 10/25 16/31 25/50 68.8 59.9 90.4 43.74 88.3 84.4 Micro Deval and deval test 4/6.3 6.3/10 10/14 % 82.6 86.31 81.96 64 73 75 25/50 42.05 38.25 Sand friability coefficient 32 31 Material classification B42 ts B42 s Unconfined Compressive Strength (UCS) after: 24 hours kN/m2 182 520 14 days 683 2671 28 days 715 2807 Note: D10, D30 and D60 represent the percentage of soil particles that are smaller than 10, 30, and 60%, respectively TABLE II. CHEMICAL COMPOSITION OF THE PHOSPHATIC LIMESTONE (TYPE 1) AND LIMESTONE (TYPE 2) WASTE Major elements (wt %) Trace elements (ppm) P2O5 SO3 CO2 CaO Al2O3 MgO Fe2O3 SiO2 Na2O K2O LOI F H2O COrg Pb Zn Cu Type1 0.40 0.72 0.02 37.84 0.70 4.66 0.35 10.40 0.42 0.04 18.80 2.05 1.54 0.22 30 60 2.50 Type2 0.89 0.03 39.06 49.77 0.25 5.24 0.26 2.30 0.09 0.01 40.70 0.40 0.72 0.02 30 32.5 3.00 IV. RESULTS AND DISCUSSION A. Chemical and Mineralogical 1) X-Ray Diffraction (XRD) The XRD pattern of the two samples is illustrated in Figure 6. It shows the presence of the apatite mineral class with variable substitution rates of CO� �� ,F� and OH� , including carbonate-fluorapatite [Ca10(PO4)5CO3F1.5(OH)0.5], fluorapatite [Ca5(PO4)3F], carbonate-apatite [Ca10(PO4)6], carbonate- hydroxyapatite [Ca10(PO4)3(CO3)3(OH)2], hydroxyapatite [Ca5(PO4)3(OH)], and hydrated phosphate, but the gangue elements are basically represented by calcite [CaCO3], quartz [SiO2], dolomite [CaMg(CO3)2], and gypsum [CaSO4] [39-40]. Carbonate-fluorapatite is the dominant phase indexed in a hexagonal symmetry (SG: P63/m) according to the ASTM XRD data reference 98-003-4653 [41]. However, limestone is richer than phosphatic limestone in calcite, quartz, and dolomite. 2) Chemical Analysis The chemical analysis results of the two phosphate waste types is presented in Table II. The results show a high percentage of major elements CaO, SiO2, and MgO for Type 1 Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10009 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... and CaO, MgO, and SiO2 for Type 2. However, Type 1 has higher concentrations of P2O5. The chemical composition confirms that the mineral composition of phosphatic limestone and limestone contains four main minerals: carbonate- fluorapatite, calcite, dolomite, and quartz. The results are in agreement with the findings of [25, 34-43]. Fig. 5. Classification of studied waste samples: A: fine soil, B: sandy and gravely soil with fine particles, and D: soil insensitive to water. (a) (b) Fig. 6. XRD analysis of Kef-Essenoun mine waste: (a) phosphatic limestone, (b) limestone. B. Basic Characteristics The waste materials used in this study were grayish and beige in color for type 1 and type 2 respectively, with dry moisture content due to the arid climate of the region. The pH values of the tailings are 6.8 and 7.8, indicating basic pH. The specific gravity of limestone is lower than that of phosphatic limestone due to the presence of P2O5 in the latter. The phosphatic limestone sample is non-plastic, and thus, the measurement of the plastic limit and index was avoided. However, the limestone sample has a Plasticity Index (PI) of 9.6% which was validated by the methylene blue test. C. Mechanical Behavior of the Materials 1) Compaction Characteristics The results of compaction tests of the waste materials, in terms of dry density and measured water contents, are given in Figure 7. (a) (b) Fig. 7. Corresponding modified proctor compaction curves for mine wastes of (a) phosphatic limestone, (b) limestone. The 85% and 100% saturation curves are also shown. The results indicate that the limestone waste provides the highest MDD of 2.00g/cm 3 and OMC of 14.15%. Generally, the compaction characteristics depend on both the grain size distribution and the specific gravity of the materials. In this case, the presence of cenospheres (hollow particles of large size) is the main cause for the lower density of the phosphatic limestone samples. Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10010 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... 2) California Bearing Ratio (CBR) Figure 8 shows the values of both unsoaked CBR and soaked CBR after 4 days of curing in water related to the MDD. It can be observed that the CBR values of the two types of samples increase as the MDD increases. It is also noticed that the phosphatic limestone waste gives a value of soaked CBR of 10.5%, indicating medium bearing capacity material, while the obtained value of soaked CBR of 18.7% of limestone indicates that it can be used as an appropriate material for the foundation layers of pavements. The FSI of samples obtained for type 1 and type 2 samples are 0.303% and 0.308%, respectively. These results show that these waste materials are not expansive (IS 2720 (Part XL)). Fig. 8. CBR values related to MDD. 3) Los Angeles and Micro-Deval The variation of LA and MD values is shown in Table I. The LA values range from 59.9% to 90.4% for phosphatic limestone and from 43.64% to 95.88% for limestone for all the considered granular classes. The results indicate that limestone waste gives more suitable values, but these waste materials are unsuitable for pavement constructions. The values of LA and MD tests of materials have to be less than 45%. Sand Friability (FS) coefficient is an indicator to assess the resistance of untreated sandy materials used for pavement subgrade to traffic loading. The FS values of the samples are 32% and 31% for type 1 and 2 materials, respectively. The recommended limit for this use is FS ≤ 60. 4) Unconfined Compressive Strength (UCS) The UCS of the mining waste samples was tested after 1, 14, and 28 days of curing as shown in Figure 9. It is well known that the materials gain in strength overtime and the magnitude of compressive strength increased with increasing MDD of the compacted granular material. It was also shown that the compressive strength of limestone at 28 days is 3.9 times larger than that of the phosphatic limestone. On the other hand, the mechanical characteristics do not deteriorate with time. The limestone closes the interior ports by cementing the grains (lime reacts strongly with water and compaction energy), favored by the plasticity of the compacted material. In this case, limestone and rock behave similarly and the compressive resistance increases over time. Furthermore, the phosphatic limestone does not cement during compaction due to the absence of plasticity and the presence of a large content of friable phosphate, which explains its lower mechanical resistance. Fig. 9. UCS of samples cured for 1, 14, and 28 days. V. POSSIBILITY OF USING WASTE MATERIALS IN ROAD CONSTRUCTION For the road material field the general rating of the mining wastes as sub-grade materials ranges from fair to poor. The phosphatic limestone waste is considered a water-sensitive material, found in a very dry hydrous state (ts) and is not normally reusable in the embankment construction or capping layer, but in certain cases, its humidification can be considered to bring it to the s (dry) or m (normal) state. The use of limestone waste material could be allowed in road construction with treatment by hydraulic binders. This treatment requires prior measurement of their mechanical strength. For compaction procedure, the very dry soil is considered as being impossible to compact properly by standard methods. In both dry (s) and very dry (ts) states, those soils are not easy to compact to form stable fill structures. The catalog of the National Agency for Technical Control of Public Works Algerian for new pavement design [44], requires the use of well-graded (GW) materials with PI less than 10% and LA less than 40% in the base layer. The findings indicate that waste rock materials, which are categorized as B42ts and B42s, respectively, should be used with caution as backfill and capping materials for road paving. They need to be treated with a hydraulic binder, such as cement, to increase their mechanical and physical qualities, raising their classes as a result. Increasing the mechanical properties of the tailing materials to be used as pavement sub-base materials will be cost effective and ecologically friendly since it will result in thinner sub-base layers and will maybe reduce the thickness of the pavement layer. In this case, stabilization is the best choice. As the mine is expanded, the waste piles created by its exploitation will ultimately result in great environmental and ecological issues. From the economic and environmental perspectives, the reuses of such waste are beneficial. 10 15 20 25 30 35 40 20 Unsoaked CBR Phosphatic Limestone D r y D e n si ty C B R (% ) Limestone MDD Soaked CBR 18 Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10011 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... VI. CONCLUSIONS The management of tailings and waste from mines and quarries is an essential requirement to limit their environmental, ecological, and geotechnical impacts. In the current research work, a characterization of two tailings from the Kef-Essenoun mine (phosphatic limestone and limestone) was investigated in order to allow reusing these materials in pavement foundations. The main findings of this investigation can be summarized as follows:  The waste materials contain mainly CaO, SiO2, and MgO. The phosphatic limestone has a much higher concentration of P2O5 (22.66 wt%) than limestone (0.89 wt%). In terms of trace elements, very low concentrations of Pb, Zn, and Cu were detected. The mineralogical composition of the two phosphate wastes contains four main minerals: carbonate- fluorapatite, calcite, dolomite, and quartz.  The materials are well-graded gravel containing all grain sizes from cobbles down to clay. The particles were of angular shape with very low plasticity index. They have no grains larger than 50mm, a passing proportion from of 80μm sieve less than 12%, and less than 70% for the 2mm sieve.  The Los Angeles and Micro-Deval coefficients of the studied materials exceeded 45%, and they are classified as B42ts (phosphatic limestone) and B42s (limestone).  From the points of mechanical behavior and applicability in road construction, the values of CBR and UCS, increase with MDD and the UCS increases with curing age.  The mechanical performance of limestone waste is more appropriate than phosphatic limestone's, and is governed essentially by the phosphate content (P2O5 wt%). The mechanical proprieties are improved with higher phosphate content. The phosphatic limestone presents low plasticity and a larger proportion of friable phosphate which lead to less material compaction.  In terms of environmental impact, the efficient reuse of mining waste in the road sector field helps reduce the production of waste, thereby minimizing the environmental damage and ensuring sustainable construction. Both waste materials considered in this study could be used in pavement structure construction provided that they are treated with hydraulic binders. Based on this study, the presented methodology could constitute a starting point for the investigation of the reuse of the mining waste of Kef-Essenoun mine in the field of road construction. VII. DECLARATIONS A. Author Contributions Rachida Malaoui conducted all the physical and geotechnical characterization tests, investigation, formal analysis, and the writing of the original draft. Abderraouf Soukeur interpreted the chemical and mineralogical characterizations. The geological part was conducted by Rabah Kechiched. The interpretation of the results and the writing of the paper were done by Rachida Malaoui, Adel Djellali, and Abderraouf Soukeur. El Haddi Harkati and Mohamed Redha Soltani were responsible for conceptualization, supervision, writing, reviewing, editing, and funding acquisition. B. Funding This work is funded by the Environmental Laboratory under the Grant No. A01L05UN120120210001. ACKNOWLEDGMENT The authors are grateful to the National Company of phosphate SOMIPHOS for providing samples and filed assistance. We would also like to thank the staff of the Civil Engineering laboratory of Larbi Tebessi University. We thank warmly Mr. Malik Atout for his help in the X-ray analysis and Mrs. Med El-Nadir Ktir and Med Saleck Ahmed for their aid in the accomplishment of the laboratory tests. LIST OF ABBREVIATIONS CBR California Bearing Ratio Corg Organic carbon content FSI Free Swelling Index LA Los Angeles abrasion value LOI Loss on Ignition MBV Methylene Blue Value MDD Maximum Dry Density MD Micro Deval value Mt/yr Million tons per year OMC Optimum Moisture Content PI Plasticity Index UCS Unconfined Compressive Strength XRD X-Ray Diffraction REFERENCES [1] M. Amrani, Y. Taha, A. Kchikach, M. Benzaazoua, and R. Hakkou, "Valorization of Phosphate Mine Waste Rocks as Materials for Road Construction," Minerals, vol. 9, no. 4, Apr. 2019, Art. no. 237, https://doi.org/10.3390/min9040237. [2] S. Lidelow, J. Macsik, I. Carabante, and J. Kumpiene, "Leaching behaviour of copper slag, construction and demolition waste and crushed rock used in a full-scale road construction," Journal of Environmental Management, vol. 204, pp. 695–703, Dec. 2017, https://doi.org/10.1016/ j.jenvman.2017.09.032. [3] A. Djellali, M. S. Laouar, B. Saghafi, and A. Houam, "Evaluation of Cement-Stabilized Mine Tailings as Pavement Foundation Materials," Geotechnical and Geological Engineering, vol. 37, no. 4, pp. 2811– 2822, Aug. 2019, https://doi.org/10.1007/s10706-018-00796-8. [4] T. H. Nguyen, T. T. T. Nguyen, T. T. H. Nguyen, and V. T. Phan, "The Feasibility of Applying Waste Concrete as Coarse Aggregates in New Concrete," Engineering, Technology & Applied Science Research, vol. 12, no. 5, pp. 9192–9195, Oct. 2022, https://doi.org/10.48084/etasr.5206. [5] A. Arulrajah, J. Piratheepan, M. Ali, and M. Bo, "Geotechnical Properties of Recycled Concrete Aggregate in Pavement Sub-Base Applications," Geotechnical Testing Journal, vol. 35, no. 5, pp. 743– 751, Aug. 2012, https://doi.org/10.1520/GTJ103402. [6] A. Arulrajah, J. Piratheepan, M. M. Disfani, and M. W. Bo, "Geotechnical and Geoenvironmental Properties of Recycled Construction and Demolition Materials in Pavement Subbase Applications," Journal of Materials in Civil Engineering, vol. 25, no. 8, Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10012 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... pp. 1077–1088, Aug. 2013, https://doi.org/10.1061/(ASCE)MT.1943- 5533.0000652. [7] J. Zhang, F. Gu, and Y. Zhang, "Use of building-related construction and demolition wastes in highway embankment: Laboratory and field evaluations," Journal of Cleaner Production, vol. 230, pp. 1051–1060, Sep. 2019, https://doi.org/10.1016/j.jclepro.2019.05.182. [8] Z. Bian, J. Dong, S. Lei, H. Leng, S. Mu, and H. Wang, "The impact of disposal and treatment of coal mining wastes on environment and farmland," Environmental Geology, vol. 58, no. 3, pp. 625–634, Aug. 2009, https://doi.org/10.1007/s00254-008-1537-0. [9] L. Haibin and L. Zhenling, "Recycling utilization patterns of coal mining waste in China," Resources, Conservation and Recycling, vol. 54, no. 12, pp. 1331–1340, Oct. 2010, https://doi.org/10.1016/j.resconrec. 2010.05.005. [10] F. A. Al-Fahdawi, A. I. Al-Hadithi, and J. A. Al-Asafi, "The Mechanical Properties of Ferrocement Mortar with Waste Plastic Fibers at Elevated Temperatures," Engineering, Technology & Applied Science Research, vol. 12, no. 5, pp. 9347–9350, Oct. 2022, https://doi.org/ 10.48084/etasr.5209. [11] I. M. Khan, S. Kabir, M. A. Alhussain, and F. F. Almansoor, "Asphalt Design Using Recycled Plastic and Crumb-rubber Waste for Sustainable Pavement Construction," Procedia Engineering, vol. 145, pp. 1557– 1564, Jan. 2016, https://doi.org/10.1016/j.proeng.2016.04.196. [12] H. A. Hasan, L. H. A. Mohammed, and L. G. G. Masood, "Effect of rubber tire on behaviour of subgrade expansive Iraqi soils," IOP Conference Series: Materials Science and Engineering, vol. 870, no. 1, Mar. 2020, Art. no. 012066, https://doi.org/10.1088/1757-899X/870/ 1/012066. [13] M. M. Disfani, A. Arulrajah, M. W. Bo, and R. Hankour, "Recycled crushed glass in road work applications," Waste Management, vol. 31, no. 11, pp. 2341–2351, Nov. 2011, https://doi.org/10.1016/j.wasman. 2011.07.003. [14] M. M. E. Zumrawi and F. O. A. Khalill, "Experimental Study of Steel Slag Used as Aggregate in Asphalt Mixture," American Journal of Construction and Building Materials, vol. 1, no. 1, Feb. 2017, Art. no. 12, https://doi.org/10.11648/j.ajcbm.20170101.12. [15] A. Mohajerani, J. Vajna, T. H. H. Cheung, H. Kurmus, A. Arulrajah, and S. Horpibulsuk, "Practical recycling applications of crushed waste glass in construction materials: A review," Construction and Building Materials, vol. 156, pp. 443–467, Dec. 2017, https://doi.org/ 10.1016/j.conbuildmat.2017.09.005. [16] J. P. Castro-Gomes, A. P. Silva, R. P. Cano, J. Durán Suarez, and A. Albuquerque, "Potential for reuse of tungsten mining waste-rock in technical-artistic value added products," Journal of Cleaner Production, vol. 25, pp. 34–41, Apr. 2012, https://doi.org/10.1016/j.jclepro.2011.11. 064. [17] V. Dubois, N. E. Abriak, R. Zentar, and G. Ballivy, "The use of marine sediments as a pavement base material," Waste Management, vol. 29, no. 2, pp. 774–782, Feb. 2009, https://doi.org/10.1016/j.wasman. 2008.05.004. [18] C. S. Reddy, S. Mohanty, and R. Shaik, "Physical, chemical and geotechnical characterization of fly ash, bottom ash and municipal solid waste from Telangana State in India," International Journal of Geo- Engineering, vol. 9, no. 1, Dec. 2018, Art. no. 23, https://doi.org/ 10.1186/s40703-018-0093-z. [19] T. G. dos Santos, L. F. R. Martins, and E. R. Sosa, "Technological Characterization of Tailings from Iron and Gold Mining with a Geoenvironmental Focus for Reuse in Geotechnical Application," in 8th International Congress on Environmental Geotechnics, Hangzhou, China, Nov. 2018, pp. 253–260, https://doi.org/10.1007/978-981-13- 2227-3_31. [20] T. Thyagaraj, Ed., Ground Improvement Techniques and Geosynthetics. New York, NY, USA: Springer, 2018. [21] N. Bheel, M. A. Jokhio, J. A. Abbasi, H. B. Lashari, M. I. Qureshi, and A. S. Qureshi, "Rice Husk Ash and Fly Ash Effects on the Mechanical Properties of Concrete," Engineering, Technology & Applied Science Research, vol. 10, no. 2, pp. 5402–5405, Apr. 2020, https://doi.org/ 10.48084/etasr.3363. [22] S. Ahmari and L. Zhang, "Utilization of cement kiln dust (CKD) to enhance mine tailings-based geopolymer bricks," Construction and Building Materials, vol. 40, pp. 1002–1011, Mar. 2013, https://doi.org/ 10.1016/j.conbuildmat.2012.11.069. [23] A. B. Salahudeen, A. O. Eberemu, and K. J. Osinubi, "Assessment of Cement Kiln Dust-Treated Expansive Soil for the Construction of Flexible Pavements," Geotechnical and Geological Engineering, vol. 32, no. 4, pp. 923–931, Aug. 2014, https://doi.org/10.1007/s10706-014- 9769-0. [24] "BioData - Aquatic Bioassessment Data for the Nation," USGS. https://apps.usgs.gov/biodata/. [25] B. Boumaza, R. Kechiched, and T. V. Chekushina, "Trace metal elements in phosphate rock wastes from the Djebel Onk mining area (Tébessa, eastern Algeria): A geochemical study and environmental implications," Applied Geochemistry, vol. 127, Apr. 2021, Art. no. 104910, https://doi.org/10.1016/j.apgeochem.2021.104910. [26] J. L. Figueroa, L. Zhou, and W. F. Chang, "Use of Phosphate Mining Waste in Secondary Road Construction," in Transportation Research Record, Ithaca, New York, USA, Aug. 1987, vol. 2, pp. 59–64. [27] W. Shen, M. Zhou, and Q. Zhao, "Study on lime–fly ash– phosphogypsum binder," Construction and Building Materials, vol. 21, no. 7, pp. 1480–1485, Jul. 2007, https://doi.org/10.1016/j.conbuildmat. 2006.07.010. [28] W. Shen, M. Zhou, W. Ma, J. Hu, and Z. Cai, "Investigation on the application of steel slag–fly ash–phosphogypsum solidified material as road base material," Journal of Hazardous Materials, vol. 164, no. 1, pp. 99–104, May 2009, https://doi.org/10.1016/j.jhazmat.2008.07.125. [29] A. A. Ahmed and A. Z. M. Abouzeid, "Potential Use of Phosphate Wastes As Aggregates in Road Construction," Journal of Engineering Sciences, vol. 37, no. 2, pp. 413–422, Mar. 2009, https://doi.org/ 10.21608/jesaun.2009.125357. [30] A. N. Ally, M. M. Blanche, U. J. P. Nana, M. M. Grâce, N. François, and C. Pettang, "Recovery of Mining Wastes in Building Materials: A Review," Open Journal of Civil Engineering, vol. 11, no. 4, pp. 379– 397, Nov. 2021, https://doi.org/10.4236/ojce.2021.114022. [31] H. Idrissi et al., "Sustainable use of phosphate waste rocks: From characterization to potential applications," Materials Chemistry and Physics, vol. 260, Feb. 2021, Art. no. 124119, https://doi.org/ 10.1016/j.matchemphys.2020.124119. [32] S. Chabou-Mostefai, "Etude de la serie phosphatee tertiaire du Djebel Onk (Algerie): stratigraphie, petrographie, mineralogie et analyse statistique," Ph.D. dissertation, Paul Cezanne University, Aix-en- Provence, France, 1987. [33] L. Gadri et al., "The quarries edges stability in opencast mines: a case study of the Jebel Onk phosphate mine, NE Algeria," Arabian Journal of Geosciences, vol. 8, no. 11, pp. 8987–8997, Nov. 2015, https://doi.org/ 10.1007/s12517-015-1887-3. [34] R. Kechiched et al., "Comprehensive REE + Y and sensitive redox trace elements of Algerian phosphorites (Tebessa, eastern Algeria): A geochemical study and depositional environments tracking," Journal of Geochemical Exploration, vol. 208, Jan. 2020, Art. no. 106396, https://doi.org/10.1016/j.gexplo.2019.106396. [35] R. Kechiched, R. Laouar, O. Bruguier, S. Laouar-Salmi, O. Ameur- Zaimeche, and A. Foufou, "Preliminary Data of REE in Algerian Phosphorites: A Comparative Study and Paleo-redox Insights," Procedia Engineering, vol. 138, pp. 19–29, Jan. 2016, https://doi.org/10.1016/j.proeng.2016.02.048. [36] R. Kechiched et al., "Glauconite-bearing sedimentary phosphorites from the Tebessa region (eastern Algeria): Evidence of REE enrichment and geochemical constraints on their origin," Journal of African Earth Sciences, vol. 145, pp. 190–200, Sep. 2018, https://doi.org/ 10.1016/j.jafrearsci.2018.05.018. [37] Y. Kassatkine, A. Yahyaoui, and S. Chatilov, "The works of prospecting and assessment on phosphate executed in 1976–1978 in the mining district of Djebel Onk," SONAREM (Société Nationale de Recherche et d’Exploration Minière), Internal report 2, 1980. Engineering, Technology & Applied Science Research Vol. 13, No. 1, 2023, 10005-10013 10013 www.etasr.com Malaoui et al.: Geotechnical Characterization of Phosphate Mining Waste Materials for Use in ... [38] "Technical report on the exploitation of the Djebel El Onk quarry preliminary exploitation plan of the Bir el Ater deposit," CERAD, Algeria, 2017. [39] D. Nettour, M. Chettibi, G. Bulut, and A. Benselhoub, "Beneficiation of phosphate sludge rejected from djebel onk plant (Algeria)," Mining of Mineral Deposits, vol. 13, no. 4, 2019, https://doi.org/10.33271/ mining13.04.084. [40] L. Bounemia and A. Mellah, "Characterization of crude and calcined phosphates of Kef Essennoun (Djebel Onk, Algeria)," Journal of Thermal Analysis and Calorimetry, vol. 146, no. 5, pp. 2049–2057, Dec. 2021, https://doi.org/10.1007/s10973-020-10167-2. [41] A. Soukeur, A. Szymczyk, Y. Berbar, and M. Amara, "Extraction of rare earth elements from waste products of phosphate industry," Separation and Purification Technology, vol. 256, Feb. 2021, Art. no. 117857, https://doi.org/10.1016/j.seppur.2020.117857. [42] R. Buccione, R. Kechiched, G. Mongelli, and R. Sinisi, "REEs in the North Africa P-Bearing Deposits, Paleoenvironments, and Economic Perspectives: A Review," Minerals, vol. 11, no. 2, Feb. 2021, Art. no. 214, https://doi.org/10.3390/min11020214. [43] S. Ferhaoui et al., "Rare earth elements plus yttrium (REY) in phosphorites from the Tébessa region (Eastern Algeria): Abundance, geochemical distribution through grain size fractions, and economic significance," Journal of Geochemical Exploration, vol. 241, Oct. 2022, Art. no. 107058, https://doi.org/10.1016/j.gexplo.2022.107058. [44] CTTP, Catalogue de Dimensionnement des Chaussees Neuves. Algiers, Algeria: Organisme National de Controle Technique des Travaux Publics, 2001.