JPS607999A - Method of removing finely divided particle-shaped sediment from river, sea, lake and marsh, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a river, ? fU% lakes, marshes, etc. {flowing or stagnant water or collection of water
c Oewffisscr).

As the flow rate of water slows down, drift stones and sediment accumulate in rivers and the sea. This accumulation obstructs shipping and reduces the storage capacity of canals and dams.

In this case, the sediment has a very negative impact on water quality due to the anaerobic decomposition process and flotation phenomenon. During floods, sediments further narrow the cross-sectional area of the channel, making it impossible for large volumes of water to flow quickly and safely.

Therefore, it is essential to constantly remove the precipitates at the site where they occur. For this purpose, it is known that sediments are dredged from rivers, seas, lakes, etc. using appropriate equipment and then removed. Filling natural or man-made voids with sediment or depositing near the coast is a common practice. Fine-grained precipitates, especially sludge-like or soft mud-like precipitates containing organic components of 7:0%, are mostly used for agriculture and transported to fields.

In particular, fine-grained precipitates are highly enriched in organic and inorganic substances due to adsorption or chemical bonding.

Furthermore, in order to keep the environmental impact to an acceptable level, the sludge must be partially dewatered and then deposited in special waste dumps.

In addition to this, the occurrence of heavy metals such as cadmium is extremely problematic. The fact that this heavy metal harms human health is evidenced by the enrichment of the food chain.

Preventive measures must be taken. The installation of this safety precaution requires a very large area of land and is therefore particularly difficult in densely populated areas. Even with expensive safety and preventive measures, it is impossible to prevent some of the harmful substances flowing through groundwater from returning to rivers, lakes, oceans, etc., either directly or through clarification equipment. be. Special waste dumps are located far away from the sediment dredging site due to the difficulty of locating them. Therefore, it has to be transported a long distance to this special waste dump.

In addition to high transportation costs, this special waste dump creates a significant environmental burden.

Regarding the removal of sediment from rivers, oceans, lakes, etc., the amount of sediment generated is a problem. For example, from nesocal to d
Approximately 2 million 7,273 sediments must be dredged and removed. Is this amount 100,000 every year? Increase by 773.

But abandoned! There is a limit to the space in which sediment can be deposited at a garbage dump.

The object of the present invention is to reduce the environmental impact, shorten the transportation route, require a small amount of land, and transport the sediment to rivers, f'ios, lakes and ponds in such a way that the harmful substances that are released into the sediment are firmly bound to the sediment. The only thing to do is to provide a way to remove it.

This problem is solved according to the present invention in claim 1! The problem is solved by the method steps described in Section 1. This method 1. For the first time, the dredged precipitate is fully utilized, or IIJf↑12, so the precipitate is completely returned to the material cycle. By the method according to the invention,
High-value products are made from precipitates mixed with additives, especially waste materials. If this product is not made in this way, it must be made by consuming new raw materials. The present invention replaces the removal of sludge, which hitherto was costly in its own right, with a productive redistribution to the national economy. In this case, the product produced in this way saves new and other materials that would otherwise be processed to produce this product. Since all method steps can be carried out in one place, environmentally burdensome and costly long-distance transport is unnecessary.

All by-products generated during the implementation of the method according to the invention can be recycled. For example, coarse grains are separated and, after cleaning and sorting, are recycled, especially for the production of building materials. For example, filtrate wastewater generated during mechanical dewatering is purified in suitable clarifiers and then returned to rivers, seas, lakes, etc. for clarification. The cleaning water produced in the case of coarse-grained i'h lips is likewise purified in this clarifier 6. The sludge produced during clarification is fed together with the sediment to a dewatering device. The exhaust gas from the combustion process and the dried grain culm is purified. At this time, the remaining contents are added to the mixture together with fly ash as additives.
It is cooled to 400 degrees and used for drying. The medium heated in the heat exchanger is converted to V to generate energy. Therefore, in the method according to the present invention, a valuable light additive for the production of building materials is produced by adding waste material in a practical manner. In this case, the by-products produced during the process can always be recycled.

The produced lightweight additive has a small unit weight, good compressive strength, and good insulation properties. Therefore, it is particularly suitable for the production of building stones with good heat insulation properties, and as an additive for light and concrete construction. In this case, it can also be used in other fields.

Other features of the invention are defined in the claims and below.
The defeat and the drawings are revealed.

Embodiments of the present invention shown in the figures will be described in detail below.

The method according to the invention essentially consists of the sawing steps shown in FIG. In this case, the main flow of the method i″
L is indicated by a thick black arrow.

The sediment is dredged by a dredger 2 mounted on a pontoon 1 and fed to a processing plant, for example via a cargo ship 4. If the entire processing plant is installed, for example on a ship, the dredger 2 can feed the sediment directly to the processing plant. The precipitate 3 is sorted according to grain size and is mechanically sieved, for example in a sieving device 5, to separate coarse grains. In principle, other methods for classifying the precipitate can be used, such as, for example, hydraulic separation methods. Coarse particles are washed in a washing device 9 and then sorted, for example according to particle size, and stored in a silo 7. The sorted coarse grains are fed in particular to the building material production department, and therefore in particular to the material stream.
No waste is produced during sieving. Instead of sorting the coarse grains, they can be crushed and further processed with the precipitate.

The remaining sediment is mechanically dewatered, preferably in a belt-conveyor filter press 8. A dry matter content of 45 mm is obtained.

The filtrate wastewater generated at this time is collected in the receiver 9 and supplied to the clarifier IO, where the chemical value of the wastewater is π [The purified wastewater is purified to below the acceptable limit value. Therefore, the purified wastewater can be directly disposed of in rivers, oceans, lakes, etc., and returned to the natural cycle.

In addition to the mechanical dewatering using a conveyor belt filter press as shown in the examples, centrifugal separators, drying ovens/towers, [other technical drying methods can be used] You can also dry the air in the same way as 1.

The sludge generated in the clarifier io is returned via the conduit 12 to the belt conveyor type filter press 8vc, so 4
) + water 71)I During clarification and purification, virtually no unusable waste products are generated. Water used in cleaning equipment/
When supplied to the 11r clarifier 10, the waste discharged together with the waste water when separating the coarse particles of the sediment 3 is reused.
'L is convenient.

It is advantageous to clarify only a portion of the filtrate waste water together with the dirty wash water coming from the washing device 6 and to discharge it into the ordinary sewerage system. In self-propelled plants, a receiver is provided.Suitable purification stages and equipment are incorporated when necessary for the separation of heavy metals from the filtrate wastewater.

Some of the methods described above already have the following advantages: That is, there is an advantage that substantially no waste is generated from the dredging of the sediment 3 to the dewatering, and that recyclable materials or materials that can be returned to the natural cycle are generated.

Precipitate 3 was reduced to a dry matter content of 45% or less.
Manufacturing can be carried out in fixed or mobile plants. Mobile plants are installed, for example, on ships. This vessel can be moored to the dredging site and the supply of sediment can take place either directly from the dredging station or via a floating conveying unit as shown in FIG.

After dehydration with Helt conveyor type filter press 8,
Additives such as fly ash, modified clay or other fine-grained mineral additives are mixed into the precipitate. In this case, it has been found that it is preferable for the precipitate to be mixed with a dry weight of 70% and an additive of 30%. In this case, as additives, fly ash, clay or similar substances can be used alone or in combination. This mixture has traditionally been supplemented with at least one contaminant such as sludge, oil, particularly refined waste oil, other suitable contaminants or mixtures thereof in a weight percentage of 5%.
do. Afterwards, the precipitate 3 together with this contaminant and additive is VC
Mixed by forced mixer 13. It may be advantageous to add other additives to improve the foaming properties or surface structure. The liquid content of the individual additives and the dewatered precipitate ensures sufficient mixing for the subsequent granulation. but,
If necessary, water can be added appropriately.

The red mud mentioned above is Levc rkuse from R3ayer.
It is a by-product produced when alumina is processed into bauxite by the method of n.

Fly ash consists essentially of finely divided mineral matter. This material originates in concentrated form from the new filtration and separation equipment of a large coal power plant16.The fly ash is transported in closed conveyance vehicles11. It is then stored in a closed silo 14, from where it is fed specifically through a conduit to a forced mixer 13.

The green clay is selected in the device 15 so that it can be added to the sediment in the forced mixer 13 in finely divided form, like fly ash.

Fillers (stored in a form suitable for dispensing and, like additives, are directly charged into a forced mixer and added to the dehydrated sediment. Especially selected waste oils are used as oil. Therefore, here too, if this is not the case, waste materials with little utility value are processed together.

After adjusting the water content to a suitable state for granulation, 1
The mixture is discharged from the forced mixer and granulated. This granulation is in particular processed to pellets in a well-known pellet production device 17. The granules or pellets are then uniformly dried in a belt conveyor dryer at a consistency of 300-400 degrees, so that the granules are preheated and stable in shape. In this case, to prevent harmful substances contained in the sediment from escaping,
In particular, the precipitate is dried in such a way that the organic components of the precipitate do not appear in a degassed state. The exhaust gas from the combustion and drying processes is purified.

In this case, the dust particles generated are added to the mixture as an additive, like fly ash. For this purpose, the dust particles generated are fed to a silo 14 or to a forced mixer 13.

After drying, the granules are burnt and then foamed.

This is carried out in a kiln 19 in particular. The granules are carried towards the 11-kuri kiln, where the temperature in the area of the flame is 1000~
12 () Entering the drum 20 at − which is 0 degrees (l
Therefore, temperature control is performed.

At this temperature, granules or pellets form closed sintered films. Thus, it is ensured that the contents of the precipitate are trapped, in particular heavy metal pesticides such as cadmium, phenols, aromatic hydrocarbons, organic substances such as phosphates, etc. By rotating the drum, the granules are brought successively closer to the flame 21.

In this case, the granules or pellets are fed into the zone of highest crystallinity at 1200 degrees. The foaming process takes place when the granules pass through a rotary kiln. Through this foaming process,
Granules or pellets each obtain light material properties. In particular, by incorporating substances that retard foaming, the foaming process can be carried out in the following temperature ranges: That is, before starting the foaming process, the temperature is shifted to a range that will form a closed sintered film. This traps all the contents of the precipitate. The granules or pellets are hardened to a high final hardness by a combustion process in a rotary kiln. After leaving the rotary kiln, the granules are gradually cooled in a cooling device 22 and stored in silos 24 for further processing, in particular sorted according to grain size V.

Since a waste oil burner 23 is used in particular for igniting the rotary kiln, it is also possible to use waste material for heating. Rotary kiln at about 700 degrees 01) [Ki is 33
00-400 degrees and fed directly to belt conveyor dryer 13 for drying of the granules. Furthermore, the energy of the rotary kiln exhaust stream can be used to operate the cooling device 22 via a suitable conversion device. The illustrative device is formed by a heat exchanger through which the exhaust stream flows. In this case, the medium of the heat exchanger is evaporated and this vapor is used to generate electricity via suitable equipment.

Departure? The encapsulated granules are made into fat 6, θ of foamed clay to produce building stones or structures JT1 lightweight concrete.
11. Light Ha: Used as an additive or flocculant.

The foamed 1111 grains have a small unit weight and a high compressive strength. Architectural stone-like architectural month 2
1'1 improves the insulation and, in some cases, adds foam granules with low specific gravity to lightweight concrete for structures, which reduces the practical load.

The method according to the invention makes it possible to reuse fine sediments that accumulate in waste dumps only under severe environmental stress. This precipitate is processed into a reusable product according to the invention. This is advantageous for the national economy.

In the method according to the invention, other wastes are added to the dredged sediment, in particular only about 173 years of the total volume. In this case 1. For example, fly ash from the power plant 16 can be used as waste, so that this waste is also removed. Contaminants such as red mud, pickles, and waste oil are also waste, so high-value products can be made virtually solely from waste. Any by-products generated during the process can be recycled or recycled into products. In the method according to the present invention, it is important to stably bind the heavy metals generated from the precipitate and the toxins within the foamed granules. This removes these substances from the natural cycle as harmful substances.

In the method according to the invention, all method steps can be carried out in one place, so that long intermediate conveying devices are not required.

For example, a plant for carrying out the entire method according to the invention can be located directly on the ship. The vessel will be supplied with sediment directly from the dredging site. For that purpose, hula is good. Light additives made from sediment can be transported directly via cargo ships. In the case of such plants, it is advantageous that the precipitate does not have to be conveyed over long distances, so that in some cases the entire closed conveying conduit can be used. This ensures that only a very small number of people come into contact with the sediment.
The pathogens contained in the sediment rarely spread.

A notable advantage of a mobile plant for carrying out the method according to the invention is that it can be reused at different sites without any problems;
This is because the environmental load around the plant is limited and is -11;T, and the land area required for the transfer equipment is small.

FIG. 2 shows a plan view of a plant for carrying out the method according to the invention. In this case, the necessary equipment for sorting and dewatering the sediment is housed within the hull 30. The dredger floating on the pontoon l conveys the sediment directly to a prepared barge 31 which conveys the sediment to the hull 30. 31 barges like this
is connected to the area of the grab 32 at 3° of the hull. In this case, a grab 32 (1-1) transports the sediment to the sieving device 5. Furthermore, the hull 30 is provided with a double-belt conveyor filter press 8, a clarification device 10 and a suitable operator's cab 33. In particular , two belt conveyor type filter presses 8 are provided side by side, thereby increasing the output of the device.The dewatered sediment 6 is temporarily stored in the bottom 34 of the working area of the grab 32.

The hull 30 is connected, in particular, to a stationary anchorage 35 located in the shore area and l' for carrying out method steps (b) to (f). Grab 32 is off, I
The deposited sediment is unloaded onto a belt conveyor 36, which feeds the sediment directly to an intermediate warehouse 37.

The sediment is transferred from this intermediate warehouse to a forced mixer 13 as needed.
carried to. Forced mixer area V is raw clay storage tank 3
8, silo 14 for fly aratsuyu, and storage tank 39 for red mud
A space 40 is provided for the song as an adulterant. Furthermore, the green clay storage tank is equipped with a screening or preparation device.

The μ2 starch is mixed with additive IJ1 and contaminants according to the method according to the invention, granulated in a pelletizing device 17, dried in a belt conveyor dryer 18, and fed to a rotary kiln 19. . Following the rotary kiln, the granules are cooled in a cooling device 22, and the foamed granules are sorted and stored in a Zyro 24.

[J-Taligirun has a burner chamber 41 and a fuel layer tank 42.
``gai・'' is set. This fuel is 4! 18,'
3F = waste oil. The door device 43 serves to control the amount of foamed granules removed.

In order to increase the output of the plant, the method steps can be carried out in two or more series.

Although it is obvious, the moving or stationary plan l- can be arranged in a different form from the J-, IjL actual case depending on the operating conditions. It is expedient, for example, to arrange all the Zorants for carrying out process steps (a) to (,0) as a mobile plant on one or several hulls, which are advantageously connected. In FIG. and a stationary plant, which corresponds to separating the process at the separation point 44 in FIG.

[Brief explanation of the drawing]

FIG. 1 is a concrete flowchart of the method according to the present invention;
FIG. 2 is a schematic plan view of an apparatus for carrying out the method according to the invention. 3...Sediment 13.P.Forced mixer 19.Rerotary kiln Kazuko: Agent Patent attorney Takehisa Ito:・---1

Claims (1)

[Scope of Claims] (1) A method for removing fine-grained sediment from rivers, oceans, lakes, etc., where the sediment contains particularly harmful substances and organic matter, and which uses a device to remove fine-grained sediment from the field. In the method of excavation, the following process steps are carried out, namely: a) sorting and dewatering the dredged sediment; b) mixing with this dewatered sediment at least one O fine-grained mineral additive; C) granulating the mixture; d) drying the granules; C) combusting and simultaneously foaming the granules; n cooling and further processing the foamed combustible granules. A method characterized by: (2) A patent characterized in that the combusted granules are utilized as a lightweight additive for producing building materials; (3) Said patent characterized in that fly ash is added as a fine-grained mineral additive; The method according to claim 1 or 2. (4) The dehydrated precipitate is mixed with at least one type of additive at a ratio of about 70% to 30% by dry weight!
In any one of the claims 1 to 3, 1. Method described. (5') '4'rj selected clay is added as a fine-grained mineral additive. The method described in. (6) The method according to any one of Items 1 to 5, Item 4, of the scope of the requirements of Part 1, in which mixing of an additive consisting of clay and fly ash is considered a failure. ('7) Heavy potassium (white - any one of claims 1 to 6) characterized in that an amount of 5% or less (by weight) is added to the mixture. (8) The patent characterized in that red mud is added as a contaminant. (9) The said patent characterized in that oil, especially selected waste oil, is added as a contaminant. The method according to claim 7. (IO) Any one of claims 7 to 9, characterized in that red mud and oil are mixed and added as a contaminant. The method according to any one of the preceding claims 1 to 10, characterized in that the granules are uniformly dried. (l2) Dry (13) to prevent harmful substances from coming out and especially to prevent the granules from becoming degassed.
13. A method according to one of the preceding claims, characterized in that the granules are burned and foamed in a rotor Jv kiln (19). (14') Process according to any one of the preceding claims, characterized in that the m-compound is mixed in a forced mixer (13). (l5) Any one of the preceding claims 1 to 14, characterized in that the coarse grains are separated and refined, in particular for reuse in the production of the sludge. The method described in. (16) The precipitate is mechanically dehydrated, and the generated filtrate wastewater is purified and used in rivers, seas, lakes, etc. The method according to any one of clauses 15 to 15. (l7) Coarse particles: R11 Selective washing water and filtrate wastewater ['to be purified and returned to rivers, oceans, lakes, etc.! The above marked with I! 1. The method according to any one of claims 1 to 16-t. (18) j For drying] Rotary kiln (l9) exhaust! The method according to any one of claims 1 to 17, characterized in that the energy source γ is used as an energy source for cooling. (19) The exhaust gas from the combustion process and the drying process is purified, and the generated dust particles are added to the mixture as an additive like fly ash. The method described in any one of the preceding paragraphs. (20') J, II water? Claim 1 characterized in that the sludge generated during clearing is fed to a mechanical dewatering device, in particular together with the sediment to be treated.
19. The method according to any one of paragraphs 1 to 19. (21) The method according to any one of claims 1 to 20, characterized in that the precipitate is mechanically sieved. (22) The precipitate is sieved and dewatered in a mobile plant, and the subsequent process step (b) is carried out in an ω-size fixing plant. Method. (23) Said method characterized in that method steps (a') to (f) are carried out in one plan 1, in particular mobile. 1. The method according to claim 1. (24) The method according to claim 1, characterized in that the sludge is mechanically dehydrated in a belt conveyor type filter press (18).