FLUIDIZED SOLIDIFIED SOIL BASED ON GOLD TAILINGS, AND PREPARATION METHOD THEREOF

Abstract

A fluidized solidified soil based on gold tailings includes the following raw materials in parts by mass: 75 parts to 80 parts of gold tailings, 5.2 parts to 13 parts of a dispersant solution, and 9 parts to 16 parts of a solidifying material. A preparation method includes the following steps: mixing the gold tailings with the dispersant solution, and then stirring to obtain a suspension slurry of the gold tailings; and adding the solidifying material, and stirring to obtain the fluidized solidified soil. In the present disclosure, the gold tailings are used as a main material, combined with a special dispersant solution and a special solidifying material, and a fluidized solidified soil is prepared with fluidity suitable for pumping and a certain strength after hardening. The fluidized solidified soil prevents the pollution caused by gold tailings landfilling, and can be used as a filling material for various construction projects.

Claims

1. A fluidized solidified soil based on gold tailings, comprising the following raw materials in parts by mass: 75 parts to 80 parts of gold tailings, 5.2 parts to 13 parts of a dispersant solution, and 9 parts to 16 parts of a solidifying material; wherein the gold tailings comprise the following chemical components by mass: SiO.sub.2: 66% to 76%, Al.sub.2O.sub.3: 10% to 16%, K.sub.2O: 6% to 10%, Fe.sub.2O.sub.3: 1% to 3%, Na.sub.2O: 1% to 2%, CaO: 0.12% to 1%, and TiO.sub.2: 0.1% to 0.3%, and have a particle size of less than or equal to 1 cm; the dispersant solution is prepared by dissolving a dispersant in water and then regulating a pH value; the dispersant is compounded by the following raw materials in mass percentage: 45% to 60% of sodium hexametaphosphate, 15% to 30% of sodium tripolyphosphate, 5% to 15% of polyacrylamide, and 5% to 10% of polycarboxylic acid; and a pH regulator is a mixture of sodium hydroxide and sodium bicarbonate; and the solidifying material is compounded by a mixture A of cement, blast furnace slag, fly ash, and a water reducer, and gypsum; the mixture A comprises the following raw materials in mass percentage: 50% to 60% of the cement, 30% to 40% of S95 granulated blast furnace slag, 5% to 10% of the fly ash, and 1% to 2% of the water reducer; and the gypsum has a mass of 4% to 6% of a total mass of the cement and the S95 granulated blast furnace slag in the mixture A.

2. The fluidized solidified soil according to claim 1, wherein the dispersant solution has a mass concentration of 3% to 8% and the pH value of 7.1 to 8.0.

3. A method for preparing the fluidized solidified soil based on gold tailings according to claim 1, comprising the following steps: (1) mixing the raw materials of the dispersant uniformly to obtain the dispersant, dissolving the dispersant in the water, and then regulating the pH value to obtain the dispersant solution; (2) mixing the gold tailings with the dispersant solution, and stirring evenly to obtain a suspension slurry of the gold tailings; (3) mixing the raw materials of the solidifying material uniformly to obtain the solidifying material; and (4) adding the solidifying material into the suspension slurry of the gold tailings, and stirring evenly to obtain the fluidized solidified soil.

4. The method according to claim 3, wherein the dispersant has a mass of 0.3% to 1.2% of that of the gold tailings.

5. The method according to claim 3, wherein the solidifying material is used at 12% to 20% of a mass of the gold tailings.

6. The method according to claim 3, wherein a mass ratio of the water to the solidifying material is (0.6-0.7):1.

7. The method according to claim 3, wherein the stirring in step (2) is conducted at 50 r/min to 80 r/min for 10 min to 20 min; and the stirring in step (4) is conducted at 60 r/min to 120 r/min for 10 min to 30 min.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 shows a structural schematic diagram of a stirring device used in examples of the present disclosure.

[0029] Reference numerals: 1: Material outlet, 2: Material inlet, 3: Limit alarm, 4: Motor, 5: Wheel, 6: Drawbar, 7: Auxiliary box, 8: Auxiliary drive shaft A, 9: Impeller, Reducer, 11: Coupling, 12: Wire gauze, 13: Material outlet baffle, 14: Small gear, Large gear A, 16: Material box bracket, 17: Material box, 18: Transmission shaft C, 19: Transmission shaft D, 20: Transmission shaft B, 21: Transmission shaft A, 22: Large gear C, 23: Large gear B, 24: Large gear D, 25: Auxiliary transmission shaft B, 26: Auxiliary transmission shaft C, 27: Auxiliary transmission shaft D, 28: Bevel gear A, 29: Bevel gear B, and 30: Bevel gear C.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to better understand the present disclosure, content of the present disclosure is further illustrated below with reference to examples. However, the content of the present disclosure is not limited to the following examples.

[0031] In the following examples, the gold tailings include the following chemical components by mass: SiO.sub.2: 73%, Al.sub.2O.sub.3: 15%, K.sub.2O: 7%, Fe.sub.2O.sub.3: 2%, Na.sub.2O: 1%, CaO: and TiO.sub.2: 0.2%, and have a particle size of less than or equal to 1 cm.

[0032] In the following examples, a four-axis vertical multidirectional stirring device is adopted, and its structural schematic diagram is shown in FIG. 1. The device has four transmission shafts, and a stirring speed and stirring direction of each rotating shaft can be changed arbitrarily during the stirring. The impellers on the transmission shaft are arranged from top to bottom, and the denser the impellers go down, the materials can be stirred and mixed more fully. In this way, a fluidized solidified soil is formed with desirable integrity and high bearing capacity. During the implementation, the gold tailings and the dispersant solution enter the stirring device from a material inlet 2. After the device is started, an impeller 9 starts to rotate, a reducer 10 can control a rotating speed of the impeller 9, and a coupling 11 can control a rotating direction of the impeller 9, such that the materials are mixed evenly. The solidifying material also enters the stirring device from the material inlet 2; and after the stirring is completed, the fluidized solidified soil is discharged from a material outlet 1.

[0033] In the following examples, a slump is determined to reflect the fluidity and groutability of the fluidized solidified soil. A determination method includes: the fluidized solidified soil is poured into a trumpet-shaped slump barrel with an upper opening of 100 mm, a lower opening of 200 mm, and a height of 300 mm. After tamping, the soil is leveled and the barrels are pulled up. The fluidized solidified soil slumps due to its own weight, and a height of the highest point of the fluidized solidified soil after the collapse is subtracted from a bucket height to obtain the slump. In the following examples, an unconfined compressive strength is determined to represent a solidification strength of the fluidized solidified soil. A determination method includes: a cube test mold with a size of 70.5 mm×70.5 mm×70.5 mm was poured using the fluidized solidified soil, and demolding was conducted after 48 h. An obtained specimen was placed in a standard curing room at 20° C.±2° C. and a relative humidity of greater than 95% for 7 d, 14 d, 28 d, and 60 d, and the compressive strength of the specimen was determined using an unconfined uniaxial press.

Example 1

[0034] A method for preparing a fluidized solidified soil based on gold tailings included the following steps: [0035] (1) 50% of sodium hexametaphosphate, 30% of sodium tripolyphosphate, 10% of polyacrylamide, and 10% of polycarboxylic acid were uniformly mixed to obtain a dispersant; the dispersant was separately dissolved in water to obtain dispersant solutions with mass concentrations of 4%, 6%, and 8%, and pH values of the dispersant solutions were regulated with sodium hydroxide and sodium bicarbonate to 7.7, 7.8, and 7.9, respectively; [0036] (2) 12 groups of gold tailings were added to the dispersant solution according to the ratios in Table 1, and then mixed in a stirring device by stirring at 50 r/min for min to obtain 12 groups of a suspension slurry of the gold tailings; [0037] (3) 58% of ordinary Portland cement, 30% of S95 granulated blast furnace slag, 10% of fly ash, 2% of a water reducer, and gypsum at 6% of a total mass of the cement and the S95 granulated blast furnace slag, were mixed uniformly to obtain a solidifying material; and [0038] (4) according to Table 1, the solidifying material was separately added into 12 groups of the suspension slurry of the gold tailings, and stirred at 70 r/min for 30 min to obtain 12 groups of fluidized solidified soil.

TABLE-US-00001 TABLE 1 12 groups of gold tailings added to dispersant solution Solidifying Gold Dispersant Solidifying Dispersant: Water: Dispersant material tailings solution material gold solidifying Group concentration dosage (part) (part) (part) tailings material 1 4% 12% 80 7.00 9.60 0.35% 0.70 2 4% 15% 78 7.80 11.70 0.40% 0.64 3 4% 18% 77 8.66 13.86 0.45% 0.60 4 4% 20% 75 9.38 15.00 0.50% 0.60 5 6% 12% 80 6.67 9.60 0.50% 0.65 6 6% 15% 78 7.80 11.70 0.60% 0.63 7 6% 18% 77 8.86 13.86 0.69% 0.60 8 6% 20% 75 9.63 15.00 0.77% 0.60 9 8% 12% 80 7.00 9.60 0.70% 0.67 10 8% 15% 78 7.70 11.70 0.79% 0.61 11 8% 18% 77 9.24 13.86 0.96% 0.61 12 8% 20% 75 11.25 15.00 1.20% 0.69

[0039] The slump and unconfined compressive strengths of 7 d, 14 d, 28 d, and 60 d of the above 12 groups of fluidized solidified soils were tested, and the results were shown in Table 2. A slump of greater than 20 cm indicated that the fluidized solidified soil had desirable fluidity and groutability. The 28-d unconfined compressive strength was greater than 0.8 MPa, indicating that the fluidized solidified soil could be used in foundation reinforcement projects such as cement-soil mixing piles.

TABLE-US-00002 TABLE 2 Test Results 7-d unconfined 14-d unconfined 28-d unconfined 60-d unconfined Slump compressive compressive compressive compressive Group (mm) strength (MPa) strength (MPa) strength (MPa) strength (MPa) 1 350 0.31 0.40 0.82 1.60 2 355 0.33 0.43 0.84 1.64 3 361 0.37 0.46 0.89 1.69 4 356 0.36 0.45 0.84 1.65 5 355 0.35 0.42 0.85 1.64 6 362 0.37 0.45 0.88 1.67 7 367 0.41 0.48 0.92 1.70 8 359 0.41 0.47 0.89 1.69 9 353 0.33 0.42 0.84 1.63 10 360 0.35 0.44 0.88 1.65 11 365 0.39 0.48 0.91 1.66 12 357 0.40 0.46 0.87 1.66

Example 2

[0040] A method for preparing a fluidized solidified soil based on gold tailings included the following steps: [0041] (1) 60% of sodium hexametaphosphate, 15% of sodium tripolyphosphate, 15% of polyacrylamide, and 10% of polycarboxylic acid were uniformly mixed to obtain a dispersant; the dispersant was separately dissolved in water to obtain dispersant solutions with mass concentrations of 4%, 6%, and 8%, and pH values of the dispersant solutions were regulated with sodium hydroxide and sodium bicarbonate to 7.2, 7.3, and 7.4, respectively; [0042] (2) 12 groups of gold tailings were added to the dispersant solution according to the ratios in Table 3, and then mixed in a stirring device by stirring at 65 r/min for 15 min to obtain 12 groups of a suspension slurry of the gold tailings; [0043] (3) 60% of ordinary Portland cement, 33% of S95 granulated blast furnace slag, 5% of fly ash, 2% of a water reducer, and gypsum at 5% of a total mass of the cement and the S95 granulated blast furnace slag, were mixed uniformly to obtain a solidifying material; and [0044] (4) according to Table 3, the solidifying material was separately added into 12 groups of the suspension slurry of the gold tailings, and stirred at 90 r/min for 20 min to obtain 12 groups of fluidized solidified soil.

TABLE-US-00003 TABLE 3 12 groups of gold tailings added to dispersant solution Solidifying Gold Dispersant Solidifying Dispersant: Water: Dispersant material tailings solution material gold solidifying Group concentration dosage (part) (part) (part) tailings material 1 4% 12% 80 6.40 9.60 0.32% 0.64 2 4% 15% 78 7.61 11.70 0.39% 0.62 3 4% 18% 77 8.66 13.86 0.45% 0.60 4 4% 20% 75 9.38 15.00 0.50% 0.60 5 6% 12% 80 6.93 9.60 0.52% 0.68 6 6% 15% 78 7.80 11.70 0.60% 0.63 7 6% 18% 77 8.86 13.86 0.69% 0.60 8 6% 20% 75 9.75 15.00 0.78% 0.61 9 8% 12% 80 7.30 9.60 0.73% 0.70 10 8% 15% 78 7.70 11.70 0.79% 0.61 11 8% 18% 77 9.14 13.86 0.95% 0.61 12 8% 20% 75 10.31 15.00 1.10% 0.63

[0045] The slump and unconfined compressive strengths of 7 d, 14 d, 28 d, and 60 d of the above 12 groups of fluidized solidified soils were tested, and the results were shown in Table 4. A slump of greater than 20 cm indicated that the fluidized solidified soil had desirable fluidity and groutability. The 28-d unconfined compressive strength was greater than 0.8 MPa, indicating that the fluidized solidified soil could be used in foundation reinforcement projects such as cement-soil mixing piles.

TABLE-US-00004 TABLE 4 Test Results 7-d unconfined 14-d unconfined 28-d unconfined 60-d unconfined Slump compressive compressive compressive compressive Group (mm) strength (MPa) strength (MPa) strength (MPa) strength (MPa) 1 372 0.35 0.48 0.86 1.65 2 377 0.38 0.50 0.89 1.68 3 382 0.39 0.55 0.97 1.72 4 377 0.39 0.52 0.88 1.70 5 378 0.38 0.52 0.88 1.68 6 385 0.40 0.55 0.93 1.69 7 389 0.43 0.58 0.96 1.72 8 386 0.43 0.58 0.89 1.71 9 375 0.37 0.50 0.86 1.66 10 382 0.40 0.53 0.90 1.68 11 385 0.42 0.56 0.96 1.71 12 382 0.41 0.56 0.89 1.70

Example 3

[0046] A method for preparing a fluidized solidified soil based on gold tailings included the following steps: [0047] (1) 55% of sodium hexametaphosphate, 25% of sodium tripolyphosphate, 15% of polyacrylamide, and 5% of polycarboxylic acid were uniformly mixed to obtain a dispersant; the dispersant was separately dissolved in water to obtain dispersant solutions with mass concentrations of 4%, 6%, and 8%, and pH values of the dispersant solutions were regulated with sodium hydroxide and sodium bicarbonate to 7.5, 7.6, and 7.7, respectively; [0048] (2) 12 groups of gold tailings were added to the dispersant solution according to the ratios in Table 5, and then mixed in a stirring device by stirring at 80 r/min for min to obtain 12 groups of a suspension slurry of the gold tailings; [0049] (3) 50% of ordinary Portland cement, 40% of S95 granulated blast furnace slag, 8% of fly ash, 2% of a water reducer, and gypsum at 4% of a total mass of the cement and the S95 granulated blast furnace slag, were mixed uniformly to obtain a solidifying material; and [0050] (4) according to Table 5, the solidifying material was separately added into 12 groups of the suspension slurry of the gold tailings, and stirred at 110 r/min for 10 min to obtain 12 groups of fluidized solidified soil.

TABLE-US-00005 TABLE 5 12 groups of gold tailings added to dispersant solution Solidifying Gold Dispersant Solidifying Dispersant: Water: Dispersant material tailings solution material gold solidifying Group concentration dosage (part) (part) (part) tailings material 1 4% 12% 80 6.60 9.60 0.33% 0.66 2 4% 15% 78 7.61 11.70 0.39% 0.62 3 4% 18% 77 8.66 13.86 0.45% 0.60 4 4% 20% 75 9.75 15.00 0.52% 0.62 5 6% 12% 80 7.07 9.60 0.53% 0.69 6 6% 15% 78 7.67 11.70 0.59% 0.62 7 6% 18% 77 8.98 13.86 0.70% 0.61 8 6% 20% 75 9.88 15.00 0.79% 0.62 9 8% 12% 80 6.90 9.60 0.69% 0.66 10 8% 15% 78 7.80 11.70 0.80% 0.61 11 8% 18% 77 9.53 13.86 0.99% 0.63 12 8% 20% 75 10.31 15.00 1.10% 0.63

[0051] The slump and unconfined compressive strengths of 7 d, 14 d, 28 d, and 60 d of the above 12 groups of fluidized solidified soils were tested, and the results were shown in Table 6. A slump of greater than 20 cm indicated that the fluidized solidified soil had desirable fluidity and groutability. The 28-d unconfined compressive strength was greater than 0.8 MPa, indicating that the fluidized solidified soil could be used in foundation reinforcement projects such as cement-soil mixing piles.

TABLE-US-00006 TABLE 6 Test Results 7-d unconfined 14-d unconfined 28-d unconfined 60-d unconfined Slump compressive compressive compressive compressive Group (mm) strength (MPa) strength (MPa) strength (MPa) strength (MPa) 1 361 0.33 0.45 0.85 1.63 2 366 0.36 0.46 0.86 1.65 3 372 0.37 0.49 0.95 1.68 4 365 0.37 0.48 0.95 1.68 5 366 0.36 0.49 0.88 1.66 6 371 0.39 0.49 0.92 1.68 7 377 0.41 0.52 1.00 1.68 8 372 0.41 0.53 0.90 1.67 9 363 0.35 0.48 0.87 1.64 10 366 0.39 0.51 0.90 1.66 11 375 0.40 0.52 0.99 1.68 12 366 0.39 0.51 0.93 1.67

[0052] It is apparent that the above examples are merely listed for clear description, and are not intended to limit the implementations. Those of ordinary skill in the art can make other changes in different forms based on the above description. It is not possible to give an exhaustive list of all the examples here, and any apparent changes derived from the technical solution of the present disclosure are still within the protection scope of the present disclosure.