Method for in-situ leaching of rare-earth ores from weathering crust elution-deposited rare earth ore

[0038] Example 1

[0039] A weathering crust elution type rare earth ore in Guangdong, the rare earth composition is medium yttrium rich europium type. Rare earth average grade RE 2 o 30.086%. A hole 12 with a diameter of 15 cm is drilled under the ore body forest, and the ore taken out is judged by the hand-holding method to determine the depth of the hole entering the ore body. After holding the ore tightly, let go. If the ore is clumped, it is humus layer 1. If it is cracked or scattered It is full regolith 2 ore. It is measured that the humus layer 1 of the ore body is about 2m, the depth of the fully weathered layer 2 is about 18m, and the depth of the semi-weathered layer 3 is about 0.8m. When it touches the bedrock 4, the drilling 12 is stopped. After determination, the grades of rare earth ores in humic layer 1, fully weathered layer 2 and semi-weathered layer 3 are 0.025%, 0.089% and 0.028%, respectively. The holes 1212 of the ore body are arranged in a grid, and are only drilled along the ridge, with a hole spacing of 2m×2m and a depth of 20.8m. Insert a 21m conduit 10 with a diameter of 2cm, and fix the conduit 10 with thatch 8 (fixed by filling) in the humus layer 1, and pass through the humus layer 1 to the semi-weathered layer 3, and in the fully weathered layer 2 under the humus layer 1 In the conduit 10 part of the pipe, four liquid outlets 11 that are 90° to the conduit wall are installed in different directions up and down, and a slope is cut at 15 cm from the bottom end of the conduit 10. The liquid goes to the funnel 7 and enters the conduit 10, so that the leaching solution throws away the humic layer 1, passes through the fully weathered layer 2, and reaches the semi-weathered layer 3 directly. Choose 8wt% ammonium chloride as the leaching solution. Strictly control the level 9 of the leaching solution in the hole 12 to be below 2m so as not to contact the humus layer 1 . A diversion groove 5 is opened above the bedrock 4. The height of the diversion groove 5 is 1.6m, the width is 0.8m, and the depth is 8m. The rare earth leaching solution of liquid collection tank 6, after adding a small amount of sodium sulfide to remove impurities, precipitate rare earth carbonate with ammonium bicarbonate, and age rare earth carbonate in mother liquor for 24 hours, and plate and frame filter press filters out rare earth carbonate with a solid-to-liquid ratio of 1: 3. The rare earth carbonate product washed with clean water and dried by pressure filtration, the grade of rare earth is in RE 2 o 3 twenty four%.

[0040] Example 2

[0041] A weathering crust elution type rare earth ore in Guangdong, the rare earth composition is medium yttrium rich europium type. Rare earth average grade RE 2 o 3 0.078%. A hole with a diameter of 8 cm is drilled under the ore body forest, and the ore taken out is judged by the hand-holding method to determine the depth of the hole entering the ore body. After holding the ore tightly, let it go. If the ore clumping is humus layer 1, if it is cracked or scattered For the full regolith 2 ore. It is measured that the humus layer 1 of the ore body is about 1.2m, the depth of the fully weathered layer 2 is about 21m, and the depth of the semi-weathered layer 3 is about 0.5m. When it touches the bedrock 4, the drilling is stopped. The rare earth grades of rare earth ores in humic layer 1, fully weathered layer 2 and semi-weathered layer are 0.023%, 0.082% and 0.026%, respectively. The holes 12 of the ore body are arranged in a grid, and are drilled only along the ridge, with a hole spacing of 2m×2m and a depth of 22.7m. Insert a 23m conduit 10 with a diameter of 2.5cm, fix the plastic pipe with thatch 8 in the humus layer 1, and pass through the humus layer 1 to the semi-weathered layer 3, and in the portion of the conduit 10 in the fully weathered layer 2 under the humus layer 1, Install four 90-degree liquid outlets 11 in different directions up and down, cut out a slope at 15 cm from the bottom end of the conduit 10, put a plastic funnel 7 into the upper end of the conduit 10, and directly add liquid to the funnel 7 from the injection tap to enter the conduit 10, so that the solution is thrown Open the humic layer 1, pass through the fully weathered layer 2, and reach the semi-weathered layer 3. Select 2wt% ammonium chloride as the leaching solution. Strictly control the leach liquid level 9 in the hole below 1.2m to prevent the leach liquid solution from filling the humic layer 1. A diversion groove 5 is opened above the bedrock 4. The height of the diversion groove 5 is 1.8m, the width is 0.8m, and the depth is 10m. The rare earth leaching solution of liquid collection tank 6, after adding a small amount of sodium sulfide to remove impurities, precipitate rare earth carbonate with ammonium bicarbonate, and age rare earth carbonate in mother liquor for 24 hours, and plate and frame filter press filters out rare earth carbonate with a solid-to-liquid ratio of 1: 3. The rare earth carbonate product washed with clean water and dried by pressure filtration, the grade of rare earth is in RE 2 o 3 twenty three%.

[0042] Example 3

[0043] A weathering crust leaching type rare earth mine in Jiangxi, the rare earth composition is medium yttrium rich in europium, and the average grade of rare earth is RE 2 o 3 0.093%. A hole 12 with a diameter of 10 cm is drilled under the ore body forest, and the ore taken out is judged by the hand-holding method to determine the depth of the hole entering the ore body. After holding the ore tightly, let go. If the ore is clumped, it is a humus layer 1. If it is cracked or scattered It is full regolith 2 ore. It is measured that the humus layer 1 of the ore body is about 0.6m, the depth of the fully weathered layer 2 is about 14m, and the depth of the semi-weathered layer 3 is about 0.6m. When it touches the bedrock 4, the drilling is stopped. The rare earth grades of rare earth ores in humic layer 1, fully weathered layer 2 and semi-weathered layer 3 are 0.026%, 0.103% and 0.024%, respectively. The holes 12 of the ore body are arranged in a grid, and are only drilled along the ridge, with a hole spacing of 2m×2m and a depth of 15.2m. Insert a 15.5m conduit 10 with a diameter of 3cm, fix the plastic pipe with thatch 8 in the humus layer 1, and pass through the humus layer 1 to the semi-weathered layer 3, and in the portion of the conduit 10 in the fully weathered layer 2 under the humus layer 1, Install two 90-degree liquid outlets 11 in different directions up and down, cut out a slope at 15 cm from the bottom of the conduit 10, put a plastic funnel 7 into the upper end of the conduit 10, fill the liquid into the funnel 7 directly from the injection faucet, and then enter the conduit from the funnel 7 10. Make the solution throw away the humic layer 1, pass through the fully weathered layer 2, and reach the semi-weathered layer 3. Choose 2wt% ammonium sulfate as the leaching solution. Strictly control the leach liquid level 9 in the hole 12 below 0.6m to prevent the leach liquid solution from filling the humic layer 1 . A diversion groove 5 is opened above the bedrock 4. The height of the diversion groove 5 is 1.8m, the width is 0.8m, and the depth is 6m. The rare earth leaching solution of liquid collection tank 6, after adding a small amount of sodium sulfide to remove impurities, precipitate rare earth carbonate with ammonium bicarbonate, and age rare earth carbonate in mother liquor for 24 hours, and plate and frame filter press filters out rare earth carbonate with a solid-to-liquid ratio of 1: 4. The rare earth carbonate product washed with clean water and dried by pressure filtration, the grade of rare earth is in RE 2 o 3 25%.