FI128089B - Method for handling of ash classified as waste, product accomplished by the method, and use of the product - Google Patents

Abstract

The invention relates to a method for treating ash which is classified as waste. The ash is sorted dry according to grain size and modified for use as an additive either in the manufacture of cement, concrete, asphalt, fertilizer, slabs and / or grout and / or in earthworks, land consolidation, road stabilization or other land fill or mining. The aggregate ash selected for the particle size, mixed with gypsum waste or other additives as appropriate, is selected as the additive product. When preparing an additive for stabilizing the roadbed and other land, it is advantageous to use ash from wood burning as ash. The invention also relates to products made by the process and their use.

Description

METHOD FOR THE DISPOSAL OF ASH TO BE CLASSIFIED AS WASTE AND THE PRODUCT USED BY THE METHOD AND USE OF THE PRODUCT

The invention relates to a process for treating ash as defined in the preamble of claim 1, and to a product formed by the process defined in the preamble of claim 4 and to the use of the product as defined in the preamble of claim 6.

The process according to the invention is well suited for the combustion of ash from various materials classified as waste, such as coal fly ash, wood, peat or other biobased material, hereinafter referred to as bi ash, power plant bottom ash, oil shale ash, for processing and converting gypsum and various textile wastes considered as waste into products suitable for further processing. One suitable treatment object is coal ash, fly ash, bi ash and / or coal ash and bi ash, which is currently mostly disposed of in landfills, but which according to the invention can be suitably segregated in various grain sizes such as cement as an injectable additive, as a fertilizer, and mixed with, for example, waste gypsum or the final product of flue gas desulphurisation, as a soil conditioner, for example to stabilize the roadbed or strengthen the soil, and also to fill disused mines.

All of the ashes mentioned in this section are also referred to collectively below as ash.

Fly ash has been used in the prior art 35 for the aforementioned uses, but the results are not2

20175393 prh 09 -07-20199 have not always 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 has only slightly improved quality. Fly ash-filled cements in prior art solutions generally contain about 15-35% fly ash. The use of untreated fly ash is typically seasonal, with limited utilization rates, and the benefits obtained have been small, imposed by stringent technical limits.

There is so much waste gypsum in industrial processes that it would be economically advantageous to make it 15 re-usable. However, there has been no widespread rational utilization of waste gypsum or waste gypsum-like end product of flue gas desulphurisation in power plants. Gypsum waste gypsum has been tried to be mixed with fly ash for coal power plants and peat plants for soil improvement and road bed stabilization, but results have not been desired because the mixed gypsum fly ash mixture has not hardened sufficiently hard.

Cement, for example blast furnace cement, has been used as a binder according to the prior art, for example in stabilizing roadbeds. However, cement is relatively expensive and not very environmentally friendly due to its manufacturing method. To reduce the amount of cement, fly ash mixed with cement has also been used to improve and stabilize the soil in roadbeds and other land areas. In this case, the fly ash used was generally fly ash from power plant waste, unsorted and untreated, as mentioned above.

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One of the prior art stabilization methods is layer stabilization, which is a method of improving the road structure in which the road bearing layer or the upper part of the bearing layer is bonded with bitumen, cement or blast furnace sand. One pilot project for road stabilization, using fly ash from peat burning (8.4%) and dihydrate gypsum (56.1%) and blast furnace cement (35.5%) to stabilize the old roadbed, has been carried out in 10 Maaninka, Finland in 1999. publication 2008 UUMA Inventory Report, Pt 16207/01 / 30-1700 and 3600-5240 Kvarkinniementie (Maaninka) Phospho-gypsum and fly ash; in mass structure and as a binder for layer stabilization. However, the problem with this solution is that the cement has to be used in a relatively large amount, which due to its manufacturing method is not environmentally unfriendly. In addition, the report does not mention that fly ash was sorted according to its grain size into fractions of a certain size and that only fly ash with a specified grain size was used.

The finer particle size of bio-ash is often enriched with toxic residues due to fuel, whereby such ash should not be used as a fertilizer, for example in forest fertilization. At the rough end, toxic residues are not enriched, so coarser bio-ash can be used for fertilization. However, ash has generally been used as it is, unsorted, which could not be properly used for fertilization.

WO2016135383A1, WO2014044905A2, CN1143053A,

US2002124775A1, US3533819A, US8663685B1 and CN101239810A are known solutions in which fly ash is used as an additive for various applications.

The object of the present invention is to eliminate the aforementioned drawbacks and to provide an inexpensive and reliable method for treating ash which is classified as waste. The aim is to increase the utilization of ash, for example len5 ash, in the concrete industry, asphalt construction and land improvement, land consolidation and mine filling, while reducing the amount of fly ash and other industrial waste going to landfills. The process according to the invention is characterized by what is stated in the characterizing part of claim 1. Accordingly, the product made by the process of the invention is characterized by what is stated in the characterizing part of claim 4 and the use of the product is characterized by what is stated in the characterizing part of claim 6 Other embodiments of the invention are characterized by what is stated in other claims.

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One of the great advantages of the solution according to the invention is the economical and very advantageous utilization of the substances otherwise classified as waste and treated as waste, such as fly ash, bi ash, oil shale ash and / or gypsum and the final product of desulphurization. This has the advantage, inter alia, of reducing the amount of CCp emitted by the cement industry in the concrete industry25, as cement is needed to produce concrete while less well-sorted fly ash replaces part of the cement. Correspondingly, limestone powder has traditionally been used as filler in asphalt production. However, suitably graded coal-fired 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.

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Another advantage is that 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 variety of filling structures, foundations and noise barriers in community construction and special applications such as ports and landfills. In addition, mixing the fly ash in the appropriate proportion with the gypsum and / or the end product of the flue gas desulphurization 10, which resembles the properties of the gypsum, increases the curing and strength properties of the mixed pulp. In addition, the mixing of the textile fibers with the above-mentioned blending mass further increases e.g. pulp toughness properties. By using wood ash for ash-gypsum mixes instead of or ash from coal and peat power plants, in many respects, even better mixing compound is obtained, for example, to stabilize roadbeds and other land. Wood ash in this context means ash in which part of the fuel is wood or the fuel 20 is wholly wood.

The solution according to the invention gives, for example, the following advantages: the manufactured products are of uniform quality and technically reliable; the products thus manufactured will replace 25 more cements; the sorting accuracy and the technical quality of the graded product are improved; the use of ash in the production of concrete is lower than with conventional unsorted fly ash, which can reduce raw material, transport and energy costs; The logical footprint of the eko30 is smaller than that of traditional fly ash.

It is also an advantage that the solution according to the invention is advantageous and that the waste treatment can be handled in a comprehensive and centralized manner, for example in a waste treatment plant or at the place of waste generation. Another advantage is that all the waste to be processed goes to different products, which reduces the amount of waste. A further advantage is that heavy metals contained in fly ash can be enriched5 into their own grain size class, whereby it is known which grain size products do not contain heavy metals. These products can then be freely used for applications where heavy metal products are not to be used. Correspondingly, a grain size 10 product known to contain heavy metals can 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 the use of the 15 characters of your application with reference to the accompanying simplified drawings, in which:

pattern 1 present invention according to the the method simplified In a plotted diagram, 20 pattern 2 present invention according to the method the most important steps more specifically photographed and pattern 3 present invention the final step of the method!

more precisely.

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In the solution of the invention, fly ash and other substances classified as industrial process waste, such as bottom ash, lumps and granular slag, gypsum and other suitable crushable waste, are processed so that they are no longer classified as waste. In the process of the invention, the fly ash and / or other materials mentioned above are sorted and classified to achieve the desired substantially accurate particle size distribution. If necessary, the material is ground to a smaller size and resold for grain size injection. In addition, additives in granular size are mixed, if necessary, in a suitable proportion to form various end products, i.e. additive products. According to the invention, their respective applications are determined for each grain size and material. Products thus graded, having different grain sizes and blends, are each stored in their own containers or in storage for future use.

Fly ash used as a raw material may be ash from coal combustion, ie coal ash. The ash can also be fly ash from biofueling, such as wood burning or peat burning, where it is called bio-ash, or the ash can also be a mixture of coal ash and bio-ash, i.e. so-called mixed ash. In addition, the ash may be of petroleum, e.g. Ash from incineration of burning rock in Estonia. In the following, these 15 ashes are also referred to collectively as "ashes" unless specifically referred to as one of these ashes.

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Similarly, the gypsum used in the process of the invention for use as an additive for screened ash 20 is preferably dihydrate gypsum. phosphorus gypsum, which is a by-product of, inter alia, phosphoric acid production and which may be regarded as waste. The stored gypsum used in the process of the invention is substantially untreated.

Figure 1 shows a simplified diagrammatic view of the method according to the invention. The ash as the raw material 7, for example, coal ash fly ash, wood pol30 ton fly ash, peat ash fly ash, bottom ash, other ash or other suitable waste classified material is delivered from the material storage site 1 to the sorting step 2 according to the invention. and, according to grain size 35, into fractions of different sizes through sieves and / or airflow

20175393 prh 09 -07-20199. The air flow may be effected, for example, by suction or blowing, for example by compressed air blowing. Preferably, the sorting of the raw material 7 is carried out dry in the sorting step 2.

In the sorting step 2, the raw material material is ground as needed and recycled until the desired grain size is achieved. According to the invention, the raw material thus sorted and, if necessary, ground 10 is passed after the sorting step 2 to either the mixing step 4 or the storage site 5. Preferably, storage site 5 is a storage location for finished products, but it can also be intermediate storage. Preferably, the sorted raw material is fed from species 15 to stage 2, mixing stage 4 or storage site 5, one fraction at a time, whereby the end products of different grain size and mixing end up in their respective storage locations 5.

Prior to the mixing step 4 or at the beginning of the mixing step, if necessary, the addition of additives 8 is carried out. In this case, the additives 8 required in the final product are added to the already sorted raw material to modify or improve the properties of the final product. Stirring 25 Step 4 may be performed at one or more mixing stations or at the point of use of the final product. The sorted material, which is taken directly from the sorting step 2 to the storage site 5, is not mixed with additives 8 at all.

Some of the raw material 7 may be that which does not need to be sorted or ground. In this case, the raw material 7 can be transferred directly to the mixing step 4 or, if there is no need to mix additives, the raw material 7 can be transferred directly to its storage location 5.

From the storage place 5, for example from a silo acting as a storage tank, the final products 9 produced according to the invention are delivered to end-users 6 as needed. a substantially solid product, such as a plate product, a pelletized product, or any other storage) product prepared and transferred to position 5 by the process of the invention.

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Figure 2 illustrates the main steps of the process of the invention in more detail, but in simplified and schematic form. Preferably, fly ash, bottom ash or other suitable waste classified as waste is used as the raw material 7 for power and / or power plants. Fly ash may be ash from wood incineration, peat incineration or other biomaterial incineration, or a combination of these, the ash of which is also referred to as bi ash. Fly ash can also be ash from coal combustion. Fly ash and bottom ash are also collectively referred to as ash.

The additive 8 may be gypsum, preferably, for example, dihydrate gypsum, classified as waste gypsum, a desulphurization end product used in power plants and power plants, cement or cement mixes, for example blast furnace cement with blast furnace slag and cement mixed together Additives 8 can be used either at one time or several at a time.

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The gypsum and / or desulphurization end product will dilute the ash mixture. Similarly, the ash activates the gypsum to harden, especially if it contains or contains wood ash from wood burning.

Correspondingly, the torn textiles contain fibers that bring toughness and tensile strength to the blend. The textiles can be either natural fibers or synthetic fibers, or both. Carbon, in turn, improves the durability10 of natural fibers by preventing them from mold and decay. Coal also improves the properties of the fertilizer product. Chemicals also provide many of the desired additional properties to the end products and remove toxic substances from the ashes.

Figure 3 illustrates the final steps of the process of the invention and the uses of the final product to be produced by the process, but in simplified and schematic form.

By treating the raw material 7, preferably coal fly ash, bi ash, or mixed ash containing both, different end products can be made to better recycle waste materials 25 that could not have been used before.

Preferably, the fly ash can be used so that the fly ash as raw material 7 is sorted according to its grain size into different products and, if necessary, mixed with additives in a suitable proportion. For example, fly ash, which has the right grain size, can be used as an additive to cement used in concrete, among other things, to improve the quality of concrete and to reduce the price of concrete and reduce cement consumption.

If the fly ash contains toxic heavy metals, they are rich35 often arriving at the finer grain end of the fly ash,

20175393 prh 09 -07-20199 When properly sorted, the coarser portion of fly ash can be utilized, for example, for fertilization and other environmentally demanding applications, while the finer-grained portion containing toxic residues can be disposed of by conventional means or used for non-toxic purposes. It can then be used, for example, to stabilize road surfaces. Different chemicals can also remove toxic residues from fly ash. Also, the toxic residues of fly ash do not cause problems 10, for example as a raw material for injection.

The process according to the invention makes the final product, for example, asphalt filler by sorting and, if necessary, grinding ash from the combustion plant as raw material 7 in step 2 to a particle size of approximately medium size, with ash particles having a particle size of about 10-60 µm. After the sorting step, the end product so sorted is either transferred to blend 4 or to its own storage site 5 20 for final use.

The process according to the invention renders the end product, for example, a raw material for the production of concrete, by making ash from raw material 7 a material of exactly the right grain size to be added to the cement, which is then used to make the concrete. The ash as raw material 7 is then sorted into a fraction having a suitable small particle size in step 2, while at the same time being careful not to break small ash particles. For this reason, grinding is not used. The raw material 7 can then be, for example, fly ash from coal-fired power stations or the above-mentioned bio-ash, which contains some or all of the ash from the burning of wood, for example, from which excess carbon has been removed.

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According to the invention, the cement suitable for concrete production is mixed with ash granules smaller than cement granules to fill only the voids between the cement granules, whereby the ashes carefully selected and selected in step 2 from granule size 5 in step 2 are mixed with only about 2-14% of the cement. for example, from about 5% to about 10%, or any appropriate percentage of the above ranges, i.e., 4, 6, 7, 8, 9, 11 or 13% 10 or portions thereof. Thus, the amount of ash used in this way can be much smaller than the approximately 15-35% of the amount of cement used according to the prior art due to the fine grain sorting. Hereby, for example, the ash particle size is as follows: D50 is between 1-8 pm, D97 is between 2-40 pm and D100 is between 3 and 80 pm. Similarly, D10 is in the range of 0.5 to 2 pm.

The process of the invention makes, for example, the final product as a fertilizer or fertilizer additive by sorting and, if necessary, milling the ash of the incinerator 7 as raw material 7 in step 2 to a medium or large particle size, preferably ash particles larger than 20 µm. . Thus, in the sorting step 2, the heavy stables and other ash toxins enriched in the smaller fraction fraction can be easily removed by transferring the entire sorted smaller fraction to other uses, such as earthworks or hazardous waste. If necessary, the material sorted as a fertilizer or fertilizer additive in step 2 is mixed in step 30 with suitable additives.

When the process according to the invention is used for the preparation of a final product which can be used as a soil improvement or soil strengthening agent in civil engineering and / or ground stabilization, the final product to be manufactured is around it.

20175393 prh 09 -07-20199 environmentally friendly, the less cement it produces, which in itself is not environmentally friendly. According to one preferred method, the soil improvement or soil consolidation agent and / or the end product 5 used for the stabilization of the roadbeds are prepared by mixing the ash graded in step 2 and, if necessary, ground gypsum and additive gypsum in an appropriate proportion in step 4. The ash used in the process is preferably fly ash from an energy or power plant incinerator, and preferably the ash is also milled in step 2 to crush the ash particles. The use of powdered ash significantly increases the curing speed of the ash-gypsum mixture and improves the final hardness and strength. A very good final result in terms of the final hardness and strength of the mixture 15 and the cure rate is achieved by using wood ash, i.e. wood-based ash. In this case, the ash may be entirely wood ash or only partially wood ash, for example mixed with other bio-ash or even coal ash. The wood-based ash-gypsum mixture, used, for example, as a backing layer to stabilize roadbeds, cures rapidly to a firm and sufficiently hard layer. Also suitable are ash from combustion in which wood-based material has been included in the incineration as one of the partial fuels, and not only afterwards.

In the manufacture of the final product for soil reinforcement and / or roadbed stabilization, it is also advantageous to add fiber to the ash-gypsum mixture, e.g. This brings toughness and tensile strength to the mixture, as already mentioned above. Carbon in the ash or carbon added as an additive also improves the durability of natural fibers by preventing them from mold and slowing down their decay.

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One suitable blend ratio of the final product used to stabilize the roadbeds is that containing 25% to 75% by weight of gypsum, 25 to 60% by weight of ash and 0 to 15% by weight of other substances such as torn textile pulp, carbon, 5 cements and chemicals. Preferably, the blend ratio is, for example, about 40-50% gypsum, about 40-50% ash and about 0-15% torn textile pulp. For example, a mixture of about 45% gypsum, about 45% ash, and about 10% torn textile pulp as a road bed stabilizer layer provides 10 fast-setting and very strong, hard and durable hardening toughening layers.

During the mixing step of the aforementioned stabilizing compound, especially if the mixing is carried out at the place of use, it is preferable to wet the mixture during mixing and / or sealing. According to a preferred embodiment, the wetting can be carried out, for example, with a solution of a lye, i.e. a NaOH solution, which acts as an activator, whereby the stabilizing mass mixture hardens faster and harder.

The process according to the invention makes the final product, for example for mining, by sorting and, if necessary, grinding the incinerator ash as raw material 7 in step 2 to the desired grain size 25 and in the mixing step 4 ash to add gypsum to cure after filling with water. which makes the mixture very fluid. Other additives may be added to the mix, but only a small amount of cement is avoided or used.

The process according to the invention can also be used to make the final product for other applications, for example powdered material, from which building boards or similar plate-like structures can be compressed like gypsum boards.

In step 2, the ash as a raw material 7 is sorted and, where appropriate, ground to a desired grain size, and in the mixing step 4, gypsum and other additives are added to give the mixture 5 the desired final shape when compressed and added.

In addition, the sorted and blended end product can also be pelletized, which prevents the product from playing, for example, during transport.

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In the above-mentioned examples, the gypsum is preferably dihydrate gypsum, i. phospho gypsum or even natural gypsum. Correspondingly, the ash is preferably fly ash from power and / or power plant incineration plants and suitably for example wood ash fly ash which is preferably sorted according to its particle size into different fractions.

According to the invention, the selected fine grain ash is selected for the additive product of cement, concrete, plate products, grout and / or mine filler, i.e. the final product to be manufactured. Thus, the ash particle size is suitably less than about 30 µm, preferably less than about 20 µm.

Correspondingly, in stabilizing the roadbed and other land areas, a material of fine and / or medium ash graded in grain size is selected for the additive product, i.e. the final product to be manufactured. Thus, the ash particle size is suitably less than about 50 µm, preferably less than about 40 µm.

In the asphalt production and construction and soil reinforcement additive product, i.e. the final product to be manufactured, the selected medium-sized coarse ash is selected. In this case, the ash particle size is suitably between 10 and 50 µm, preferably between 20 and 40 µm.

Instead, in the manufacture of the fertilizer, essentially medium and / or coarse ash graded in grain size is selected for the additive product, i.e. the final product to be manufactured.

In this case, the ash particle size is suitably above about 10 µm, preferably above about 20 µm.

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 unsorted waste material has not been possible before. For example, the use of graded and substantially uniform fly ash used in road construction to stabilize the roadbed, mixed with the correct type of waste gypsum, provides a fast and sufficiently hardening support layer for road pavement. Likewise, fly ash, which has the right grain size as an additive to the cement used in the concrete, will, among other things, improve the quality of the concrete and lower the price of the concrete and reduce the cement consumption.

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It will be apparent to one skilled in the art that 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 a grain-size li30 scavenger product, such as fly ash or other material classified as waste, is used, 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 other than those set forth above.

Claims (6)

1. A method for treating waste classified ash, in which method the ash is converted into a product for use 5 in the manufacture of either cement, concrete, asphalt, manure, slab-shaped products and / or injectors and / or in soil and construction work, stabilization of road substrates and other soil masses or in shaft filling, and in which method the ash is sorted in dry form to 10 different products based on grain size, and used on the basis of grain size in the manufacture of either cement, concrete, asphalt, fertilizers, slab-shaped products and / or injectors and / or also in soil and construction work, stabilization of road surfaces and other soil masses or in shaft filling, in which method For the manufacture of cement, concrete, slab products and grouting and / or shaft filling, grain size sorted, substantially finely divided ash is selected, and for stabilization of road substrates and other soil masses, grain size sorted, usually finely divided and / or medium coarse ash, as well as pre-ground ash, is selected. - and civil engineering works selected grain size sorted, substantially medium coarse ash, and for the production of fertilizer, grain size sorted, substantially medium coarse and / or coarse ash is selected, and when required, selected ashes are mixed in connection with the manufacture and / or use of the product with one or more additives. a product for stabilizing road substrates and other soils, gypsum is mixed with grain size sorted comminuted and / or medium coarse ash, characterized in that in the manufacture of a product for stabilizing road substrates and other soils in addition to plaster, grated textile pulp is mixed in grain size / finely sorted or medium coarse ash. 20175393 prh 09 -07-2019 2. A method according to claim 1, characterized in that about 25-75% by weight of gypsum, about 25-60% by weight of ash and not more than 15% by weight, in the manufacture of a product for stabilizing road substrates and other soil masses, is mixed. 5 other substances, such as grated textile pulp, koi and, if necessary, chemicals. A method according to claims 1 or 2, characterized in that in the manufacture of a product for stabilizing 10 road substrates and other soil masses are mixed about 40-50% by weight of gypsum, about 40-50% by weight of ash and at most 15% by weight of grated textile pulp, preferably about 45% by weight of gypsum, about 45% by weight of ash and about 10% by weight of grated textile pulp. 4. A product made by the method of claim 1 wherein one of the ingredients is ash formed in connection with the combustion of coal and / or biomass, characterized in that a product is intended for the manufacture of cement, 20, contains grain size-sorted, substantially finely divided ash, and that in a product intended for stabilization of road substrates and other soil masses, grain-sized, substantially finely divided and / or medium-sized ash, and / or medium-sized ash a product intended for the manufacture of asphalt and for soil and construction works contains grain size, substantially medium coarse ash, and that in a product intended for the production of manure, there is grain size, substantially medium coarse and / or coarse ash. if necessary, in connection with the manufacture of products, one or more additives have been incorporated into the selected ash, and that in a product intended for stabilization of road substrates and other soil masses there are gypsum mixed with sorted, finely divided and / or medium coarse ash, and advantageous in addition plaster also grated textile pulp mixed with sorted, fin herbaceous and / or medium coarse ash. 5. A product according to claim 4, characterized in that in a product intended for stabilization of road substrates and other soil masses there are about 25-75% by weight of gypsum, about 25-60% by weight of ash and at most 15% by weight of other substances, such as grated textile pulp, koi and, if necessary, chemicals, for 10 parts there is in the product about 40-50% by weight of gypsum, about 40-50% by weight of ash and not more than 15% by weight of grated textile pulp, preferably about 45% by weight of gypsum, about 45% by weight of ash and about 10% by weight of grated textile pulp. Use of a product according to claims 4 or 5 as one or more of the following: additives in the manufacture of cement, concrete, asphalt, fertilizers, disc-shaped products and / or injectors and / or soil and plant works, and as additives in stabilization. of road subsidence and other soil masses, or shaft filling.