METHOD FOR PRODUCTION OF A CLAY POWDER AND A METHOD FOR SOIL IMPROVEMENT WITH THE CLAY POWDER

Abstract

A method for production of a modified clay powder comprises the steps of: a) acquiring batch clay, and b) forming a modified clay powder with an average particle size of between 2 nm and 150 nm. The main groups of clays include kaolinite, montmorillonite, bentonite, smectite, and illite. A method for improving the stability of a soil sample comprises a steps of: a) acquiring the soil sample, b) acquiring a clay, c) forming a clay powder (nano-clay as nano green-additive) with an average particle size of between 2 nm and 150 nm, optionally preparing a suspension of the nano-clay in water, d) mixing the clay powder or the suspension of the clay powder in water with the soil sample in a weight ratio of between 1:100 and 1:1 of the clay powder to the soil sample, respectively, e) applying the mixture obtained in step d) to the required construction site, f) forming the mixture at the construction site in accordance with a predetermined construction project until a structure of predetermined dimensions is obtained, g) exposing the structure obtained in step f) to an amount of water for the curing time. Applying the mixture obtained in step e) to the predetermined construction site can be realized with a method of spraying.

Claims

1. A method for production of a modified clay powder, comprising the steps of: a) acquiring a batch clay, wherein the batch clay comprises kaolinite and/or montmorillonite and/or bentonite and/or smectite and/or illite and/or chlorite and/or vermiculite and/or talc and/or pyrophyllite, b) forming the modified clay powder with an average particle size of between 2 nm and 150 nm, wherein forming the modified clay powder is performed by grinding the batch clay in a rotating ball mill, wherein the ball mill includes a plurality of mill balls, wherein the average particle size of the modified clay powder produced is between 2 nm and 100 nm.

2. A method for improving the stability of a soil sample, the method comprising steps of: a) acquiring the soil sample, b) acquiring a batch clay, wherein the batch clay comprises kaolinite and/or montmorillonite and/or bentonite and/or smectite and/or illite and/or chlorite and/or vermiculite and/or talc and/or pyrophyllite, c) forming from the batch clay a modified clay powder with an average particle size of between 2 nm and 150 nm, d) mixing the modified clay powder with the soil sample in a weight ratio of between 1:100 and 1:1 of the modified clay powder to the soil sample, respectively, e) applying the mixture obtained in step d) to the required construction site, f) forming the mixture at the construction site in accordance with a predetermined construction project until a structure of predetermined dimensions is obtained, g) exposing the structure obtained in step f) to an amount of water for the curing time.

3. The method of claim 2, wherein the step c) of forming the modified clay powder is performed by grinding the batch clay in a rotating ball mill, wherein the ball mill includes a plurality of mill balls, wherein the average particle size of the modified clay powder produced in step c) is between 2 nm and 100 nm.

4. The method of claim 3, wherein the weight ratio of the batch clay to the plurality of the mill balls is between 1:15 and 1:30 wt/wt.

5. The method of claim 3, wherein the ball mill is configured to rotate at a rotational speed between 600 rpm and 4200 rpm.

6. The method of claim 2, wherein a weight ratio of the modified clay powder and the soil sample as ingredients for mixing in step d) is between 1:100 and 1:1 wt/wt.

7. The method of claim 2, wherein the step d) of mixing the modified clay powder and the soil sample includes mixing for a period of time from 10 minutes to 120 minutes.

8. The method of claim 2, wherein the step d) of mixing the modified clay powder and the soil sample is performed by a rotary mixer configured to rotate at a rotational speed of between 70 rpm and 120 rpm.

9. A method for improving the stability of a soil sample, the method comprising steps of: a) acquiring the soil sample, b) acquiring a batch clay, wherein the batch clay comprises kaolinite and/or and/or montmorillonite and/or bentonite and/or smectite and/or illite and/or chlorite and/or vermiculite and/or talc and/or pyrophyllite, c) forming a modified clay powder with an average particle size of between 2 nm and 150 nm, d) forming an aqueous suspension of the modified clay powder, e) placing the aqueous suspension of the modified clay powder in an ultrasonic water bath for 5-30 min to disperse the clay powder for geochemical fractionation, f) mixing the aqueous suspension of the modified clay powder obtained in step e) with the soil sample in a weight ratio of the aqueous suspension of the clay powder to the soil sample of between 1:100 wt/wt and 18:100 wt/wt, wherein the result of step f) is a spray mixture, g) applying the spray mixture obtained in step f) to the predetermined construction site, h) allowing the structure obtained in step g) to harden for a curing time.

10. The method of claim 9, wherein the step d) of forming an aqueous suspension of the modified clay powder includes forming the aqueous suspension of the modified clay powder with a weight ratio of the modified clay powder to the water between 1:100 wt/wt and 18:100 wt/wt.

11. The method of claim 9, wherein the step d) of forming the aqueous suspension of the modified clay powder includes mixing the modified clay powder and the water in an ultrasonic homogenizer.

12. The method of claim 9, wherein the modified clay powder and the water is mixed in the ultrasonic homogenizer for the period of time between 10 minutes and 45 minutes.

13. The method of claim 9, wherein the modified clay powder suspension and the soil sample is mixed for the period of time between 1 and 15 minutes.

14. The method of claim 9, wherein the modified clay powder suspension and the soil sample is mixed in a rotary mixer with a rotational speed of between 20 rpm and 80 rpm.

15. The method of claim 9, wherein applying the spray mixture obtained in step f) to the predetermined construction site is performed with a spraying device for spraying an enclosure with the aqueous suspension of the nano-clay.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These aims together with other objects and advantages which will become subsequently apparent reside in the details of the construction and operation as more fully hereinafter described and claimed, reference being made to the accompanying drawings forming a part hereof, wherein the same numerals refer to the same parts throughout.

[0029] In drawings

[0030] FIG. 1a illustrates schematically the work principle of the ball mill for the nano-clay production,

[0031] FIG. 1b illustrates schematically the work principle of another embodiment of the ball mill,

[0032] FIG. 2 illustrates field emission scanning electron microscopy (FE-SEM) image of the Micro-clay particles.

[0033] FIG. 3 illustrates field emission scanning electron microscopy (FE-SEM) image of the Nano-clay particles.

[0034] FIG. 4 illustrates a XRD diagram of the clay sample.

DETAILED DESCRIPTION OF INVENTION AND PREFERRED EMBODIMENT

[0035] Referring to the drawing, FIG. 1a shows schematically a principle of operation of a ball mill (not claimed). The ball mills are well known, therefore the construction will be not described here in details. However, operating parameters of the ball mill, for example the size and material of the balls, the weight ratio of the balls to the batch clay, rotational speed of the ball mill cylinder, inclination of the rotational axis, time of operating, etc, are changeable and are to be set according to the requirements of the output material (the nano-clay). It can be seen on FIG. 1a that during operation, the ball mill cylinder rotates according to the direction of the arrow A. The crushing medium G, which includes a plurality of metal balls of sizes 1 cm, 1.5 cm and 2 cm, rotate inside the cylinder around an axis. The bottom plate of the device and the cylinders containing the material to be grinded and/or crushed and/or shredded which is the clay powder (batch clay, M) rotate around an axis perpendicular to each other in opposite directions (one clockwise and the other counterclockwise). These movements are creating a centrifugal force. The balls first are pressed to a wall of the cylinder due to the centrifugal force caused by the rotational motion of the chamber and then the centrifugal force caused by the rotational motion of the plate dominates the force and, the balls in the cylinder are falling on the batch clay material particles in a specific position due to the gravity and are causing them to crush and ultimately convert the particles to nano size. The wording nano size or nano-clay in this description means a size from around 5 nm to around 100 nm (nanometers). In simpler terms, these methods are among the methods in which by crushing and shredding larger materials and particles into smaller particles and continuing this process to the size of nanometers, they become nanoparticles, which means a particles with the average nano size as described above. The particle size of the primary powder of the batch clay may determine the degree of purity, the shape of the material particles and the degree of quality of the material. Another construction of the ball mill (not claimed) is shown on FIG. 1b. This planetary ball mill includes a number of ball mill cylinders (grinding jars) which are rotatably placed on an independently rotatable base plate. The directions of rotation B of the grinding jars and the directions of rotation A of the base plate are opposite. The grinding balls in the grinding jars are subjected to superimposed rotational movements, the so-called Coriolis forces. The difference in speeds between the balls and grinding jars produces an interaction between the frictional and the impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill. In one example of the invention, the weight ratio of the batch clay and the metal balls put into the ball mill cylinder can be 1:5 and 1:15, the rotational speed of the cylinder can be 300-1500 rpm, the time of the operation can be 10-60 min.

[0036] FIG. 2 illustrates a Scanning Electron Microscope (SEM) images of the micro particles before the process of nano-production.

[0037] FIG. 3 illustrates a Scanning Electron Microscope (SEM) images of the nano clay particles after the process of nano-production.

[0038] FIG. 4 shows the results of the XRD experiment. The result of the XRD test is presented. The X-ray diffraction (XRD) is a versatile non-destructive analytical technique used to analyze physical properties such as phase composition, crystal structure and orientation of the powder, the solid and the liquid samples. These figures show the crystallographic structure of the clay.

[0039] In describing a preferred embodiment of the invention, specific terminology is resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.