FI125995B - Method and apparatus for the treatment of the substance to be classified as waste and use of the product obtained by the method and apparatus - Google Patents

Description

METHOD AND EQUIPMENT FOR THE DISPOSAL OF A SUBSTANCE, AND USE OF A PRODUCT MANUFACTURED BY THE METHOD AND EQUIPMENT

The invention relates to a method as defined in the preamble of claim 1 and to an apparatus as defined in the preamble of claim 6 for treating a substance classified as waste.

The method and apparatus according to the invention, i.e. the solution according to the invention hereinafter, is very well suited for the treatment of various wastes classified as waste, such as fly ash, bottom ash, volcanic material, slag and granular slag and other suitable crushable waste such as glass. and convert them into products suitable for further processing. One very suitable object for treatment is fly ash from coal-fired power plants, which is currently mostly disposed of as landfill, but which can be used according to the invention, for example, as a cement additive for concrete, asphalt, injection agent and also as a soil excavator.

Fly ash has been used according to prior art for the aforementioned uses, but the results may not have been good enough, since fly ash has been commonly used as such, without any sorting, whereby for example concrete with unsorted fly ash used as an additive any. The fly ash-filled cements in prior art solutions generally contain about 15-35% fly ash. The use of untreated fly ash is typically remote, the use rates are limited and the benefits obtained have been limited by strict technical limits.

There have also been attempts to refine fly ash with solutions based on washing technology, but these are expensive and need to be accompanied by a fly ash drying process.

It is an object of the present invention to overcome the above drawbacks and to provide an inexpensive and reliable method and apparatus for handling a substance classified as waste. The aim is to increase the utilization of fly ash, for example, in the concrete industry, asphalt construction and civil engineering, while reducing the amount of fly ash and other industrial waste going to landfills. The method according to the invention is characterized in what is stated in the characterizing part of claim 1. Correspondingly, the apparatus according to the invention is characterized by what is set forth in the characterizing part of claim 6. Other embodiments of the invention are characterized by what is set forth in the other claims.

One of the great advantages of the solution according to the invention is the economical and very advantageous re-use of materials which are otherwise classified as waste and which are treated as waste, such as fly ash. This has the advantage, among other things, of reducing the amount of CCg emissions from cement production in the concrete industry, since cement is needed to produce concrete, with less well-sorted fly ash replacing part of the cement. However, this is not the case with unsorted fly ash. Roughly estimated about 100 kg of fly ash replaces about 30 kg of cement. Correspondingly, limestone powder has traditionally been used as filler in asphalt production. However, suitably graded coal fly fly ash is well suited for asphalt paving fines because of its uniform granularity, good pore-filling capacity, suitably low water content, and alkaline nature. Because fly ash is bound in asphalt mass, its environmental impact is negligible. Fly ash, and especially fly ash graded to a suitable grain size, can replace natural soil, for example in road structures. Fly ash is well suited for a wide range of filling structures, foundations and noise barriers in community construction and special structures such as ports and landfills.

According to the invention, material treated and sorted for its particle size, such as fly ash, can be termed a micronized product for which competing products include, among other things, prior art fly ash and silica (SiCg). The solution according to the invention has the following advantages: The manufactured products are of uniform quality and technically reliable, the products thus manufactured replace more natural materials, replace more cement, the sorting accuracy and the better technical quality of the sorted product are better; reduces raw material, transport and energy costs, the ecological footprint is smaller than traditional fly ash, and the product according to the invention is certified.

It is also an advantage that the solution according to the invention is advantageous and that the waste treatment can be handled holistically and centrally, as in a waste treatment plant. Another advantage is that all the waste to be processed goes to different products, which reduces the amount of waste. Another advantage is that heavy metals in fly ash can be separated into their own particle size class, which means that the particle size range does not contain heavy metals. These products can then be freely used for applications where heavy metal products are not to be used. Similarly, a particle size product known to contain heavy metals may be used, for example, in the manufacture of asphalt and concrete in which fly ash is in a bound form.

The invention will now be described in more detail by way of example with reference to the accompanying simplified drawings, in which Figure 1 is a simplified diagrammatic view of the method of the invention, Figure 2 is a side elevational, schematic and simplified view of a fly ash or similar waste material, and simplified one of the fly ash or similar waste sorting lines of the invention, Figure 4 is a schematic and simplified sample of freshly mixed wet concrete, and Figure 5 is a substantially enlarged and schematic representation of the sampling point shown in Figure 4 by dotted lines.

In the solution according to the invention, fly ash and other materials classified as industrial process waste, such as bottom ash, lumps and granular slag and other suitable crushable waste such as glass and volcanic material, are processed so that they are no longer classified as waste. In the method according to the invention, fly ash and / or other substances mentioned above are sorted and classified to achieve the desired substantially accurate particle size distribution. If necessary, the material is milled to a smaller size and resold to grain size sorting. In addition, each particle size and material will be assigned the correct applications. Products of different grain sizes so sorted are each stored in their own containers for future use. This process is called shorter term micronisation and, for example, concrete made with the raw material according to the invention, microbeton.

Figure 1 shows a simplified diagrammatic view of the method according to the invention. The fly ash la or other material ib suitable for this purpose, for example, classified as waste, is supplied from the material storage site 1 to the micronization process 2 according to the invention, where the material is graded and sorted according to material and grain size in various size fractions. through. The thus sorted products 3a are stored according to material and grain size in their storage place 3, for example in silos acting as storage tanks, from which the products 3a, for example fly ash screened and sorted to a specific grain size, are delivered to end users 4 of desired granulate 4a and / or concrete 4b.

Figure 2 is a side elevational, schematic and simplified view of one fly ash or similar waste sorting line 5 according to the invention. In this case, the sorted material, for example fly ash 12, is sorted into four different grain size classes. or more. The material to be sorted, for example fly ash 12, is initially guided along the feed duct 11 to a screening device 13 acting as a pre-screen, for example a mechanical vibrating screen or a wind screen, whereby oversized particles 20 and unburned carbon are separated from fly ash 12 and reintroduced, e.g. The apparatus includes means for adjusting the screen 13 according to grain size, slope angle and other desired criteria.

Material passing through screen 13 drops into a first sorting funnel 6 having a rotatable, for example, a rotatable ejector member 16, whose wings 17 disintegrate the falling material and throw a portion of the falling material forward to the second sorting funnel 7. The blowing effect is enhanced by blower 15 throw smaller and lighter materi-aalipartikkeleita towards the second lajittelusuppiloa 7. only the largest in size and heavier particles are particles of a material 12a drop into a first lajittelusuppiloon 6 and through the storage tank in the direction of the arrow 19a. The apparatus includes means for adjusting blower 14 according to blowing pressure, blowing direction, air volume and other desired criteria. In addition, the apparatus is provided with auxiliary fans, for example, on the side of the sorting line 5 in the middle of the sorting line 5. Auxiliary blowers enhance the passage of smaller sized particles, i.e. material particles 12b-12d, into their own sorting funnels 7-9.

Due to the airflow 15 of the blower 14 and the discharge member 16, lighter fly ash particles always fly in a line between two successive screening funnels 10 with open top and height adjustable baffles 10 toward the other screening funnels, from which the heaviest and second 19b direction.

Similarly, the next smallest particles 12c take flight air flow accompanying the particular partition wall 10 more than the third lajittelusuppilolle to 8, where they fall down due to its weight and still have it own storage tank through 19c in the direction of the arrow. While the size of the smallest and lightest particles 12d still flying fourth lajittelusuppiloon to 9, a rear wall 10a at the latest, they stop and fall to the lajittelusuppiloon 9, which shall continue to own a storage tank in the direction of the arrow 19d. The height of the partitions 10 of the screening funnels 6-9 also adjusts the amount of fly ash obtained in each screening funnel 7-9 and, at the same time, the particle size of the material. For example, the higher the partition 10 between the screening funnels 8 and 9, the smaller the particle size is the fly ash particles 12d that descend to the last screening hopper 9.

The screening line 5 still has a lid 18 on top of the screening funnels 7-9 to prevent the screening funnels 7-9 from getting foreign matter and the material being screened away by the air stream 15.

At the first end of the sorting line 5, in front of the first sorting hopper 6, the direction of the blower 14 and the air flow 15 it blows are very important for sorting. The airflow 15 is directed partly to the stream of particles falling from the side and from below, whereby the lighter particles partially fly upward and simultaneously towards the other sorting funnels 7-9 of the sorting line 5 and pass along the airflow to the sorting funnel 6-9. The discharge member 16 assists the air stream 15 to disperse the flow of material.

Figure 3 is a schematic and simplified plan view of one fly ash or similar waste sorting line 21 comprising a plurality of sorting lines 5a-5e corresponding to a parallel sorting line 5, which may include both the same material and completely different material. At the beginning of the sorting lines 5-5e is a waste material collection point with the necessary equipment and at one end of the lines, and at each storage container there are sorted product collection and distribution points. For example, there is preferably a carriageway between each sorting line 5-5e for the further introduction of the sorted product, or a pipeline or other suitable distribution channel for further supply of the sorted product. At the bottom right of Figure 3, the path of the smallest product 12d of line 5 from its storage silo below the sorting hopper 9 is marked for use. Other pickup and delivery points or routes are not shown in Figure 3 for clarity.

Fig. 3 shows the lowest fly ash screening line 5 previously shown in Fig. 2 having a receiving point 22 with means for receiving and guiding fly ash 12 to, for example, a .

Next to the fly ash sorting line 5, if necessary, there could also be one or more, substantially identical fly ash sorting line 5. As well as the fly ash sorting line 5 could be located alone on the entire plant. In this example, adjacent to the fly ash screening line 5 is a power plant bottom ash screening line 5a, which is substantially similar to the fly ash screening line 5, but with different processing equipment than the fly ash screening line 5. The bottom ash sorting line 5a comprises at least a bottom ash receiving point 23 and a grinding unit 28 where the bottom ash is ground to a smaller particle size before sorting into the sorting funnels 6a-9a. The screening is carried out by a screening and air blast arrangement substantially similar to the fly ash screen.

The next line may include, for example, a granular granular slag sorting line 5b, which is substantially similar to the bottom ash sorting line 5a, but which, if necessary, has different processing equipment from the bottom ash sorting line 5a. The granulated slag sorting line 5b comprises at least a slag receiving point 24 and a grinding unit 28, wherein the bottom ash is ground to a smaller particle size before sorting into the sorting funnels 6b-9b. The screening is carried out essentially with, for example, a screen and air blast arrangement similar to the fly ash screen.

The next set of lines may further include, for example, a volcanic material sorting line 5c, which is in principle substantially similar to other sorting lines in the set, but whose processing equipment is different from that of other sorting lines. The volcanic material sorting line 5c comprises at least a material receiving point 25 and a crushing unit 29 where the volcanic material is crushed and, if necessary, ground to a smaller grain size before sorting into the sorting funnels 6c-9c. The screening is carried out by essentially a screen and air blast arrangement similar to that of a fly ash screen.

The line may also include a sorting line 5d for other types of crushable waste, such as waste glass and ceramic goods, which is in principle substantially similar to other sorting lines in the line, but which, if necessary, have different processing equipment from other sorting lines. The shredding waste sorting line 5d includes at least a material receiving point 26 and a crushing unit 29 where the shredded waste is crushed and, if necessary, ground to a smaller grain size before sorting into the sorting funnels 6d-9d. The screening is carried out by essentially a screen and air blast arrangement similar to the fly ash screen, for example.

Lastly, the exemplary line has a slag sorting line 5e, which is substantially the same as other line sorting lines, but whose processing equipment is different from that of other sorting lines, if necessary. The slag sorting line 5e comprises at least a material receiving point 27 and a crushing unit 29 where the slag is crushed and, if necessary, ground to a smaller grain size before sorting into the sorting hoppers 6e-9e. The screening is carried out essentially with, for example, a screen and air blast arrangement similar to a fly ash screen.

Thus, a sorting line can have only one sorting line 5-5e, or several adjacent sorting lines 5-5e, all of which contain a product sorted from different starting materials or may also contain products sorted from the same starting materials. In addition, in a line or in a single sorting line 5-5e, the storage tanks fed by the sorting hoppers 6-9e may each contain only one grain size sorted product, or each line 5-5e may have more than one storage container having substantially the same material and material. In this case, the use of the product in question is possible even when one storage tank is out of service due to maintenance or other reasons.

It is essential for the solution according to the invention that the products made by sorting the waste material are stored in their containers sorted according to the products of essentially the desired grain size, so that the products can be easily used for their best use, such as cement admixture.

Table 1 shows an excerpt from a test result in which fly ash was sorted using a test apparatus such as the method and apparatus of the invention. In it, Product # 1 is a substantially unsorted rough starting material and Product # 5 is the finest material of all. The vertical columns show four different volume percentages: D10 corresponding to 10%; D50 corresponding to 50%; D97 corresponding to 97%; and D100, which corresponds to 100%. The decimal numbers in the columns are the grain size of the material in micrometres (pm).

table 1

For example, if you look at the lowest product # 5, you will see that the sorting has gone through 100% of the entire material through a 4 µm screen, i.e. the largest grain size of the sorted product is 4 µm. However, the generally more important criterion is the grain size of D97, which is usually sufficient instead of D100, and the product is generally rated at D50, which determines the average grain size of the product. Table 1 shows that the average fineness D50 of product # 5 is thus 1.46 µm and more than 10% of the product is material with a particle size of less than 1 µm, i.e., some of the product is already in the nanometer size range.

The handling and sorting of fly ash and other waste material used to produce products of a particular particle size will enable these products to be utilized economically and purposefully for a variety of uses for which the use of such unsorted waste material could not be previously achieved. For example, fly ash, which has the right grain size as an additive to cement used in concrete, will, among other things, improve the quality of concrete and reduce the price of concrete and reduce the consumption of cement.

By using fly ash graded to the correct grain size as the cement additive for concrete production, fly ash can be used less than prior art solutions to achieve the same result, i.e. instead of 15-35%, fly ash is only needed in the solution according to the invention. For example, the grain size of the fly ash is as follows: D50 is 1-8 pm, D97 is 2-40 pm and D100 is 3-80 pm. Similarly, D10 is in the range of 0.5 to 2 µm.

Fig. 4 is a schematic and simplified view of a freshly mixed wet concrete with reinforced cement gel 30 as a binder with reinforcements of both small stones 31 and larger stones 32. In addition, the concrete may have metal and other reinforcements, but not shown in the figure. . Also included in Figure 4 is a dotted line sampling point 33, much enlarged in Figure 5.

The concrete sample of Fig. 5 is schematic and simplified showing only how the granules 34 of the fly ash sorted according to the invention are positioned between the larger cement granules 35, thereby compacting the structure of the cementitious mortar. Without the cement granules 35, the fly ash particles 34 of smaller size would leave too much empty space between the cement granules 35, for example about 2-15%, which would weaken the structure. The fly ash used as a cement additive, which is smaller in size than the cement granules and which has the right grain size for use, thus physically increases the cement strength and thus reinforces the cement and concrete cast by fly ash. Similarly, drying cracks and frost resistance, among other things, are reduced.

According to prior art cement fly ash is added to the cement during the cement grinding step. However, in this case it is not possible to obtain fly ash of the required grain size in relation to the properties of the cement grade being produced. According to the invention, fly ash of just the right grain size is added to the cement only at the final stage of cement grinding or after the grain size of the fly ash depends on the purpose of the cement. Cement containing granules 35 of such a large size is added fly ash of larger grain size and fly ash of less granular cement is added to cement containing smaller granules 35. This gives high quality cement mixes for various applications.

In the preparation of cementitious grouting agents for filling various gaps and cracks, such as concrete or rock cracks, the solution of the invention provides a very good result, since the addition of cement fly ash or other suitable granulated product of the above mentioned waste materials is highly graded. From time to time, fly ash 35, less granular in cement granules, is added to the desired product, as shown in Figure 5, to compact the structure. The cement mixture may also be made such that the cement granules 35 are smaller in size than the fly ash granules 34, but again in this case it is essential to use a sorted fly ash of known grain size.

According to the invention, the cement suitable for concrete production is mixed with fly ash particles 34 smaller than cement granules 35 to fill only the voids between the cement granules 35, whereby only about 2-14% of cement is mixed with the selected fly ash according to the desired cement quality. 12% and preferably, for example, about 5-10% or any suitable percentage of the above ranges, i.e. 4, 6, 7, 8, 9, 11 or 13% or parts thereof. Thus, the amount of fly ash used in this way can be much smaller than the approximately 15-35% of the amount of cement used in the prior art, due to the fine grain sorting.

It will be apparent to one skilled in the art that the various embodiments of the invention are not limited to the examples above, but may vary within the scope of the following claims. It is essential that an additive product, such as fly ash or other material classified as waste, is sorted according to the purpose of use, so that the grain size of said additive product is substantially accurately known.

It will also be apparent to one skilled in the art that the sorted additive product of the invention may also be made by methods and apparatus other than those set forth above.

Claims (9)

1. A method for treating a substance classified as waste, which process comprises transforming the substance classified as waste into an additive such as cement, concrete, asphalt and / or grout, as well as earthworks, whereby the substance classified as waste is sorted into different products and stored and used as an additive in cement, concrete, asphalt and / or grout as well as in construction, characterized in that after pre-screening, the stream of material to be sorted is allowed to drop downward and air is blown downwardly into the falling material stream so that the larger particles (12a) and next, the largest particles (12b) are directed to a screening hopper (7) accompanying the air stream (15), and so on, and the smallest particles (12d) is guided along with the air stream to the last sorting hopper (9). Method according to Claim 1, characterized in that the material to be classified as waste is sorted according to its particle size by first removing the largest particles therefrom by means of a screening device (13) or the like, after which the material stream is led to a mechanical separation such as a rotary discharge element air with a blower (14) by means of a force which conveys particles (12a-12d) of different grain sizes into sorting funnels (6-9) of their size and further into their own storage tanks. Method according to claim 1 or 2, characterized in that the different materials classified as waste, such as ash, bottom ash, volcanic matter, granulated slag, slag and crushed waste such as glass, porcelain and the like, are sorted according to grain size for each of their stores. their containers as separate products which are used either as additives or as such for various uses. Method according to one of the preceding claims, characterized in that the material to be classified as waste is sorted according to the particle size into different products having, for example, one or more of the following particle sizes: D10 is between 0.5 and 2 pm; D50 is between 1 and 8 pm; D97 is between 2-40 pm and D100 is between 3-80 pm. Method according to any one of the preceding claims, characterized in that the cement used in the production of concrete is mixed with fly ash as an additive in an amount of about 2-14% of the cement, suitably for example about 3-12% and preferably about 5-10% or any suitable percentage. , or 4, 6, 7, 8, 9, 11, or 13 percent, or portions thereof. Apparatus for treating material to be classified as waste, comprising at least a screening device (13) and a rotary ejector (16) for supplying the material to be sorted into the sorting hoppers (6-9) arranged in succession in a sorting line (5-5e), characterized in that 6-9) are separated from one another by open and adjustable partitions 10 at their upper end in the same sorting line (5-5e), and that at the first end of the sorting jet (5) there is a fan (14) with an air flow directed downwardly upwards a stream of material falling into the first sorting hopper (6), and which fan (14) is arranged to blow the lightest and smallest particles (12d) over the sorting funnels (6-8) from the blower (14) to the furthest sorting hopper (9); the smallest particles (12c) over the funnels (6-7) of the blower ( 14) looking at the second farthest sorting hopper (8) and then the lightest and next smallest particle size (12b) over the sorting hopper (6) from the blower (14) looking at the second farthest sorting hopper (8). Apparatus according to Claim 6, characterized in that the apparatus comprises a plurality of sorting lines (5-5e) arranged side by side for the same or different waste, each arranged to sort the waste according to the sorted grain size into different products in its own product containers. 8. Apparatus according to claim 6 or 7, characterized in that the material to be classified as waste is sorted on a sorting line (5-5e) according to the grain size into different products having, for example, one or more of the following grain sizes: D50 is between 1 and 8 pm; D97 is between 2-40 pm and D100 is between 3-80 pm. Use of a substance classified as a different product according to the method according to claim 1 and / or the equipment according to claim 6 as a cement additive, concrete additive, asphalt additive, grouting additive, impregnating additive and / or earth-building agent.