AU2008286149A1

AU2008286149A1 - Damming method for permeable red mud dam with red mud from sintering process

Info

Publication number: AU2008286149A1
Application number: AU2008286149A
Authority: AU
Inventors: Ruixue Jia; Xingdong Jiang; Jing Liu; Yinghui Qiao; Tongguo Qiu; Chen Wang
Original assignee: CHINA ALUMINIUM INTERNAT ENGIN
Current assignee: CHINA ALUMINIUM INTERNATIONAL ENGINEERING Corp Ltd
Priority date: 2007-08-09
Filing date: 2008-08-05
Publication date: 2009-02-12
Anticipated expiration: 2028-08-05
Also published as: CN101363217A; AU2008286149B2; WO2009018719A1

Description

A Method of Constructing a Sintered-by red mud Filter Dam Technical Field This invention relates to a method of constructing a tailing dam, particularly relates to a method adapted for constructing a dam using sintered-by red mud. Background Red mud is waste discharged during the production of alumina from alumyte. Those tailings discharged during said production of alumina oxide by a sintering process are called sintered-by red mud which is generally transported to the red mud stock yard through pipes. The ratio between the red mud solid and red mud attached liquid in the sintered-by red mud is 1:4. The sintered-by red mud contains quite more coarse particles due to the sintering process applied for producing alumina oxide, so the red mud attached liquid, after being placed in the stock yard, can be separated from the red mud to form clarified liquid, and the sintered-by red mud can be cemented with a strength which is equivalent to that of low grade cements. Thus, the sintered-by red mud may be used for dam construction. Certain conditions are required for the sintered-by red mud to be cemented with a strength, namely, first hydrating (supplying water to) the sintered-by red mud, then lowering water content therein, so that the strength is quickly achieved with a high grade. Thus, in order to build a dam, it is necessary to quickly discharge water in the sintered-by red mud. To those skilled in the art, an urgent object confronted thereby lies in: how to first hydrate the sintered-by red mud and then solidify the red mud by water discharging so as to form a red mud dam which is safe, reliable, simple in construction and low in cost. Summary of the Invention 1/8 An object of the invention is to provide a method of constructing a sintered-by red mud filter dam, said method comprising the steps of: first hydrating the sintered-by red mud and then solidifying the red mud by water discharging so as to form a red mud dam which is safe, reliable, simple in construction and low in cost. To achieve the above object, the following steps are hereby taken in the invention: constructing a dam body 1 of the sintered-by red mud dam layer by layer by means of hydraulic filling; arranging draining devices 2 in the dam body I at intervals along with the elevation of the dam body 1 of the red mud dam. Constructing a layer of the dam body 1 of the sintered-by red mud dam by means of hydraulic filling comprises the following steps: first, constructing the original sintered-by red mud into an annular small dike into which the sintered-by red mud is discharged via discharging pipes 4, then coarse particles quickly subside; next, digging in the small dike a notch 5 through which water and fine particles flow into the pond, the fine particles then subside so that the clarified water is formed in the pond, whereby the coarse particles and the small dike together forming a layer of dam body of the sintered-by red mud. Said draining devices are arranged at intervals of 3-7 meters. Said draining devices are constituted by multi layers of horizontal draining webs and vertical draining facilities. Said horizontal draining webs are constituted by transverse draining prisms and longitudinal draining prisms. Said transverse draining prisms and said longitudinal draining prisms have column-like structures formed by placing pebbles of different diameters on different layers. Said transverse draining prisms and said longitudinal draining prisms are arranged at a slope angle of 1-20%. Water discharged from said horizontal draining webs is directed into a water back system via said vertical draining facilities. Said vertical draining facilities are constituted by an intercepting ditch 2/8 provided in a dam surface and a discharging ditch at the bottom of the dam and along the outer side of the dam. Said intercepting ditch is a ditch having a slope angle of 1-20% and made of alkali proof concrete. Said discharging ditch is constructed by a ditch dug out in the red mud surface and paved with pebbles. Each layer of the dam body of the sintered-by red mud dam has a height of 300-500mm. The invention possesses the following advantages and effects: 1) Constructing a sintered-by red mud dam by means of hydraulic filling is advantageous in that: coarse particles can be selected from the red mud under the action of water power to construct a dam so as to reduce labors required for dam construction and reduce costs thereof. 2) Employing a filter dam with additionally provided draining devices in the dam body, can not only accelerate water draining and solidifying of the surrounding red mud so as to form with a strength, but also effectively lower the immersion line of the dam body by inserting it into the dam body so as to provide help for the stability of the dam body. The dam is reasonable in structure, with clear back water and long in service life. 3) The sintered-by red mud dam so constructed meets the requirements of first hydrating the red mud and then solidifying the red mud by water discharging to build a safe and reliable dam body. 4) The sintered-by red mud dam so constructed can be used to accommodate other tailings discharged, which makes wastes valuables and occupy less lands as well as saves costs. Description of the Drawings Fig.1 is a cross-sectional illustration of the sintered-by red mud filter dam. 3/8 Fig.2 is an A-A side sectional illustration of fig. 1. Fig.3 is a structural illustration of the draining devices according to the invention. Fig.4 is a cross-sectional structural illustration of the transverse draining prisms and the longitudinal draining prism according to the invention. Legends: 1. dam body; 2. draining devices; 3. annular small dike; 4. discharging pipes; 5. notch; 6. draining prism; 7. longitudinal draining prism; 8. intercepting ditch; 9. discharging ditch. Description of the Preferred Embodiments As shown in figs.1 and 2, constructing the specific structure of the sintered-by red mud filter dam by means of hydraulic filling comprises the follows steps: constructing a dam body I of the sintered-by red mud dam layer by layer by means of hydraulic filling; and arranging draining devices 2 at intervals of 3-7 meters along with the elevation of the red mud dam, each layer of the sintered-by red mud dam having a height of 300-500mm. Constructing a layer of dam body 1 of the sintered mud dam by means of hydraulic filling comprises the following steps: first, constructing the original sintered-by red mud into an annular small dike 3 into which the sintered-by red mud is discharged via discharging pipes 4, then coarse particles quickly subside; next, digging in the small dike 3 a notch 5 through which water and fine particles can flow into the pond, the fine particles then subside so that clarified water is formed in the pond, whereby the coarse particles and the small dike 3 together forming a layer of dam body 1 of the sintered-by red mud dam. As shown in fig.3, said draining devices 2, constituted by multi layers of horizontal draining webs and vertical draining facilities provided in the dam, is used to connect the vertical draining facilities for collecting draining water with the exterior of the horizontal draining webs. The horizontal draining webs are constructed by transverse draining prisms 6 and longitudinal draining prisms 7 4/8 which, as shown in fig.4, have column-like structures formed by placing pebbles of different diameters on different layers and are arranged at a slope angle of 1-20%. Water discharged from the horizontal draining webs is directed into a water back system via the vertical draining facilities which are constituted by an intercepting ditch 8 in a dam surface and a discharging ditch 9 at the bottom of the dam and along the outer side of the dam. The water drained from the transverse draining prisms 6 and the longitudinal draining prisms 7 quickly flows into the discharging ditch 9 located on the outer side of the dam through the intercepting ditch 8 made of concrete, said intercepting ditch 8 having a slope angle of 1-20%. The discharging ditch 9 is constructed by a ditch dug out in the red mud and paved with pebbles. 5/8

Claims

1. A method of constructing a sintered-by red mud filter dam, characterized by constructing a dam body (1) of the sintered-by red mud filter dam layer by layer by means of hydraulic filling, and providing draining devices (2) in the dam body (1) spaced apart from each other along with the elevation of the dam body (1) of the red mud dam.

2. The method according to claim 1, characterized in that: constructing a layer of dam body (1) of the sintered-by red mud dam by means of hydraulic filling comprises the following steps: first, constructing the original sintered-by red mud into an annular small dike (3) into which the sintered-by red mud is discharged via discharge pipes (4), then coarse particles quickly subside; next, digging in the small dike (3) a notch (5) through which water and fine particles flow into the pond, the fine particles then subside so that clarified water is formed in the pond, whereby the coarse particles and the small dike (3) together forming a layer of dam body (1) of the sintered-by red mud.

3. The method according to claim 1, characterized in that said draining devices (2) are provided at intervals of 3-7 meters.

4. The method according to claim 1 or 3, characterized in that said draining devices (2) are constituted by multi layers of horizontal draining webs and vertical draining facilities.

5. The method according to claim 4, characterized in that said horizontal draining webs are constituted by transverse draining prisms (6) and longitudinal draining prisms (7).

6. The method according to claim 5, characterized in that said transverse draining prisms (6) and said vertical draining prisms (7) have column-like structures formed by arranging pebbles of different diameters on different layers.

7. The method according to claim 6, characterized in that said transverse draining prism (6)s and said vertical draining prism (7)s are arranged at a slope 6/8 angle of 1-20%.

8. The method according to claim 4, characterized in that water drained from said horizontal draining webs is directed to a water back system via said vertical draining facilities.

9. The method according to claim 4, characterized in that said vertical draining facilities are constituted by an intercepting ditch (8) provided on a dam surface and a discharging ditch (9) provided at the bottom of the dam and along the outer side of the dam.

10. The method according to claim 9, characterized in that said intercepting ditch (8) is a ditch having a slope angle of 1-20% and made of alkali proof concrete.

11. The method according to claim 9, characterized in that said discharging ditch (9) is constructed by a ditch dug out in a red mud surface and paved with pebbles.

12. The method according to claim 9, characterized in that each layer of the dam body (1) of the sintered-by red mud dam has a height of 300-500mm. 7/8