Stability of Sensor Network based on Non-linear Data Analysis for in situ Leaching of Ionic Rare Earth Ore Bodies under Similar Simulation Experiments

Figure 1:

Figure 2:

Figure 3:

Figure 4:

Test sample water content test_

Numbering	1	1.39	3
Aluminum box weight (g)	17.05	2	17.56
Box + wet soil mass (g)	30.54	17.22	39.10
Box + drying soil mass (g)	30.34	30.54	38.82
Mass of water (g)	0.20	30.36	0.28
Dry soil mass (g)	13.29	0.18	21.26
Moisture content (%)	1.5	13.14	1.32
Average moisture content (%)	1.36

Comparison of the error between the actual water pressure value and the measured water pressure value_

Sensor number	Measured water pressure (kPa)	Measured value of pore water pressure (kPa)	Measured accuracy (%)
1#	1.39	1.35	−0.20
2#	1.39	1.42	+0.15
3#	1.39	1.43	+0.20
4#	2.23	2.2	−0.15
5#	2.23	2.25	+0.10
6#	2.23	2.28	+0.25
9#	1.14	1.12	−0.10
10#	1.14	1.1	−0.20
11#	1.14	1.18	+0.20

Comparison of several short-range wireless technologies_

Technical standard	Bluetooth	Wi-Fi	Mobile communications	ZigBee
Working frequency	2.4 GHz	2.4 GHz	0.8/0.9 GHz 1.8/1.9 GHz	868 MHz/915 MHz/2.4 GHz
Coverage	10 m	100–200 m	Depends on network	50–300 m
Transmission rate	1 M/s	11–54 M/s	50k–2M	10–250k
Power consumption	Big	Big	Small	Minimum
Cost	High	Low	Highest	Low
Delay	Short	Long	Shorter	Shorter
Confidentiality	Good	Better	Good	Good
Scalability	Difference	Good	Good	Good
Network capacity	Small	Big	Big	Big
Technical complexity	More complicated	Easy	Easy	Easy

Content of RE ions in the leaching solution of magnesium sulfate leaching in each time period_

Leaching liquid	Leaching time/h	RE weight collected in leaching solution (mg)
		A1	B1	C1
Magnesium sulfate	1	0	0	0
	2	1.51	2.24	1.15
	3	8.54	10.76	7.56
	4	38.25	42.47	38.69
	5	10.58	12.01	15.28
	6	5.47	3.76	6.89
	7	0.78	0.66	0.45
	8	0.12	0.1	0.1

Content of RE ions in the leaching solution of clear water leaching in each time period_

Leaching liquid	Leaching time/h	RE weight collected in leaching solution (mg)
		A2	B2	C2
Shimizu	1	0	0	0
	2	0	0	0
	3	0	0	0
	4	0	0	0
	5	0	0	0
	6	0	0	0
	7	0	0	0
	8	0	0	0