Experimental Study on Electroosmotic Improvement of Mechanical Properties of Tailings Mud

doi:10.12068/j.issn.1005-3026.2025.20239060

Abstract

Abstract:

To investigate the feasibility and effectiveness of improving the mechanical properties of tailings mud by electroosmosis， voltage gradient and voltage loading method were used as variables， and the self-made electroosmotic test chamber was used to carry out indoor electroosmotic tests on copper tailings mud and phosphorus tailings mud. By analyzing the drainage volume and current attenuation during the electroosmosis， as well as the moisture， dry density and shear strength of the tailings mud after electroosmotic improvement， combined with the energy consumption of electroosmosis， the effectiveness and best way for improving the mechanical properties of tailings mud by electroosmosis were explored. The test results show that electroosmotic drainage is positively correlated with voltage intensity and voltage loading stages. Compared with single-stage voltage loading， the current attenuation trend of multi-stage voltage loading slows down. After the end of electroosmosis， the water content of tailings mud is lower， the dry density is larger， the shear strength is higher， and the improvement effect of mechanical properties is better. During the electroosmotic process， the average energy consumption of multi-stage voltage loading is lower than that of single-stage loading. The best way to improve the mechanical properties of tailings mud by electroosmosis is 15—20—25—30 V four-stage voltage loading.

Key words: tailings mud, electroosmotic dewatering, multi-stage loading, shear strength, energy consumption analysis

CLC Number:

X 936

Zuo-an WEI, Xue-yi ZHANG, Hong-wei GUO, Ting LU. Experimental Study on Electroosmotic Improvement of Mechanical Properties of Tailings Mud[J]. Journal of Northeastern University(Natural Science), 2025, 46(4): 151-158.

Figures/Tables 18

Fig.1 Particle size cumulative distribution curves of copper tailings and phosphorus tailings

Table 1 Characteristic particle sizes of copper tailings and phosphate tailings

尾矿类别	特征粒径/μm				不均匀系数C_u	曲率系数C_c
尾矿类别	d₁₀	d₃₀	d₅₀	d₆₀	不均匀系数C_u	曲率系数C_c
铜尾矿	28.77	76.44	127.04	166.61	5.79	1.22
磷尾矿	6.59	10.96	21.07	30.57	4.64	0.60

Fig.2 Electroosmotic experimental device

Table 2 Experimental scheme for electroosmotic

试验组别	电压加载方式	试验组别	电压加载方式
T0	空白对照，静置	T7	15－30
T1	15	T8	20－25
T2	20	T9	20－30
T3	25	T10	15－20－25
T4	30	T11	15－20－30
T5	15－20	T12	20－25－30
T6	15－25	T13	15—20—25—30

Fig.3 Copper tailings mud loading voltage and time

Fig.4 Phosphorus tailings mud loading voltage and time

Fig.5 Displacement in electroosmotic process of copper tailings mud

Fig.6 Displacement in electroosmotic process of phosphorus tailings mud

Fig.7 Current attenuation and drainage change during the electroosmotic process of copper tailings mud

Fig.8 Current attenuation and drainage change during the electroosmosis of phosphorus tailings mud

Fig.9 Moisture of copper tailings mud at different positions after electroosmosis

Fig.10 Moisture of phosphorus tailings mud at different positions after electroosmosis

Fig.11 Dry density of copper tailings mud at the positive electrode after electroosmosis

Fig.12 Dry density of phosphorus tailings mud at the positive electrode after electroosmosis

Table 3 Cohesion and internal friction angle of

试验组别	阴极处		阳极处
试验组别	黏聚力 c/kPa	内摩擦角φ/(°)	黏聚力 c/kPa	内摩擦角φ/(°)
Tc0	1.44	46.29	6.43	45.57
Tc1	5.37	46.29	14.94	44.36
Tc4	12.32	48.80	17.60	50.45
Tc7	4.54	48.43	16.24	47.60
Tc9	9.40	46.65	7.83	50.44
Tc10	15.07	44.00	15.76	48.29
Tc12	8.96	51.23	15.22	51.89
Tc13	17.78	48.92	13.72	52.73
Tp0	4.33	31.10	4.23	30.53
Tp1	5.33	30.95	6.55	30.58
Tp4	7.34	31.80	7.45	32.09
Tp7	6.25	33.34	3.20	35.17
Tp9	5.67	32.28	6.98	33.88
Tp12	6.59	33.13	8.78	33.77
Tp13	8.49	33.75	13.29	34.76

Fig.13 Shear strength of copper tailings mud at the positive electrode after electroosmotic test

Fig.14 Shear strength of phosphorus tailings mud at the positive electrode after electroosmotic test

Table 4 Calculation results of tailings mud

试验组别	电渗总能耗 $W$	平均排水能耗 $W ¯$
试验组别	kW·h	kW·h·mL^-1
Tc4	2.03×10^-2	448.34
Tc9	1.68×10^-2	302.40
Tc12	1.58×10^-2	214.64
Tc13	1.41×10^-2	179.36
Tp4	0.148	3 540.24
Tp9	0.153	2 653.61
Tp12	0.160	2 575.89
Tp13	0.161	2 390.39

Table 4 Calculation results of tailings mud

试验组别	电渗总能耗 $W$	平均排水能耗 $W ¯$
试验组别	kW·h	kW·h·mL^-1
Tc4	2.03×10^-2	448.34
Tc9	1.68×10^-2	302.40
Tc12	1.58×10^-2	214.64
Tc13	1.41×10^-2	179.36
Tp4	0.148	3 540.24
Tp9	0.153	2 653.61
Tp12	0.160	2 575.89
Tp13	0.161	2 390.39

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