RU2212287C1 - Method of decontamination of solid wastes - Google Patents

Abstract

FIELD: environment control; decontamination of solid domestic and industrial wastes, construction wastes inclusive. SUBSTANCE: proposed method includes grinding and processing of wastes in mixer where binder solution is also fed; used as binder is aqueous paste containing at ratio of 1:1-2 with water the following components, mass-%: dispersed aluminosilicates, 40-75; Portland cement, 5-25; ground quick lime, 5-15; calcium sulfate semihydrate or phosphogypsum, 5-15; alkali-earth metal chloride, 1-2; ferrous chloride, 0.2-1; mass treated in mixer is heated and is compressed by passing it through extruder. Activated sludge may be additionally fed to mixer at ratio of 0.2-0.5: 1 relative to mass of dry components of aqueous paste. Grinding of waste is performed to obtain particles with sizes more than 10-15 mm in the amount of no more than 10% of total mass of ground wastes. After extrusion, mass thus obtained is packed in hermetic container, polyethylene bags, for example. EFFECT: enhanced efficiency of decontamination; facilitated procedure; low cost of process and reduced labor consumption. 5 cl, 1 dwg, 3 tbl, 3 ex

Description

 The invention relates to the field of environmental protection and can be used for the disposal of solid household and industrial, including construction, waste.

 A known method for the disposal of solid waste, which consists in applying to the waste surface a protective layer of a partially breathable hardening foam based on a urea resin; the protective layer is applied by successive pouring of the waste surface with non-combustible or non-combustible hardening foam, each subsequent pouring is carried out after the material of the previous pour has cured, see RU 2014164, 09 V 1/00.

 This method is very expensive due to the high cost of hardening foam based on synthetic resin and the complexity of its preparation in the foam generator; In this case, expensive foaming agents and a special acidic medium are required to ensure the polymerization of the urea resin. In addition, it should be pointed out that a sufficiently reliable sealing of the waste with the help of a hardening foam is impossible, since microorganisms isolated from atmospheric oxygen pass from the aerobic development mode to the anaerobic mode. As a result of this, gases are released and accumulated, which subsequently inevitably destroy the foam layer.

 Also known is a method for the disposal of solid waste, which consists in the fact that the garbage, crushed to the desired particle size state, is mixed with a binder solution to the required consistency, and the waste-concrete mixture prepared in this way is placed in prepared forms for subsequent curing and obtaining from it waste-concrete briquettes used as cores having a low bulk density and low thermal conductivity in the manufacture of artificial building two-composite stones, see RU 2080991, B 28 B 23/00, 01/19/1993.

 This technical solution is taken as a prototype of the present invention.

 This method can be considered to some extent justified only if the waste is chemically neutral and sterile. However, in practice, such waste does not occur. Waste always contains degradable organic matter and aggressive chemically unbalanced compounds. Organic substances, being isolated by concrete from air oxygen, are subject to anaerobic biofermentation processes. The gases formed in this process, as well as the processes of reduction of oxides that occur during this process, cause the destruction of the structure of waste concrete briquettes. Inorganic aggressive pollutants also have a destructive effect on concrete mass. In addition, this method is technologically time-consuming and complicated, since it involves many auxiliary technological operations: manufacturing a concrete mold, installing a briquette in a mold with its centering relative to the sides of the mold, pouring concrete mixture into the mold. The last operation in practice is extremely difficult, since for the uniform distribution of the solution in the sinuses of the form, special vibration equipment is required. In this case, it will be necessary to provide rigid fixation of the mutual arrangement of the core and the shape, which is practically unattainable under vibration conditions.

 It should also be noted that this technology requires a large consumption of cement, sand, mortar plasticizers, which are expensive materials.

 The garbage in the prototype method does not adequately fulfill the role of a filler, since with its macroporosity of 60-70%, the bulk will be filled with concrete. It should also be emphasized that any solution containing sand and a hydrated binder has a capillary-porous structure and cannot be a reliable insulator, since a material with such a structure is water-permeable, which causes heavy metals and other ecotoxicants to be released into the environment.

 The present invention is based on the solution of the problem of creating a method for the disposal of solid waste, which would be effective even if the waste contains organic substances, as well as aggressive, chemically unbalanced compounds. In addition, the task of simplifying and cheapening the process of neutralization, reducing its complexity.

According to the invention, this problem is solved due to the fact that in the method of neutralizing solid waste, including grinding and processing it in a mixer, into which a binder solution is also supplied, an aqueous paste containing in the ratio of 1: 1-2 with water the following components is used: , wt.%:
Dispersed aluminosilicates - 40-75
Portland cement - 5-25
Quicklime, ground - 5-15
Semi-aquatic gypsum or phosphogypsum - 5-15
Alkaline earth metal chloride - 1-2
Ferric Chloride - 0.2-1
and the mass processed in the mixer is heated and compacted by passing it through an extruder; activated sludge is additionally fed into the mixer in a ratio of 0.2-0.5: 1 to the total weight of the dry components of the aqueous paste; the waste is crushed to a level of particles with sizes above 10-15 mm not more than 10% of the total mass of the crushed waste; after extrusion, the resulting mass is packaged in a sealed container, plastic bags can be used as a sealed container.

 The applicant has not identified sources containing information about technical solutions identical to the present invention, which allows us to conclude that it meets the criterion of "novelty."

 The implementation of the claimed distinguishing features of the invention determines the appearance of the object fundamentally important new properties.

 If in the prototype method the concrete mixture, in the opinion of its authors, should fulfill the function of a structural insulating material, then in the claimed method, the proposed composition has a neutralizing effect on the processed waste; in this case, microflora is destroyed, which prevents the biofermentation of waste, and aggressive, chemically unbalanced substances (acids, alkalis, salts, including heavy metals) are absorbed by the mineral matrix formed as a result of alkaline hydrolysis of dispersed aluminosilicates.

 As a result, solid wastes are not only mechanically isolated, but participate in the formation of the framework of the synthesized monolithic water and gas impermeable structure, which is due to the formation of aluminosilicate sol-gel phases, while the briquettes formed according to the prototype method have, as indicated above, water - and gas permeable capillary-porous structure.

 These circumstances, according to the applicant, indicate that the claimed technical solution meets the criterion of "inventive step".

 The technological cycle is illustrated by the diagram shown in the drawing.

 Waste arrives in block 1 of acceptance and sorting, where the recovery and sorting of recyclable components: metals, plastics, paper, cardboard, glass, rags. Sorting in block 1 in a specific example is provided using a chain visor conveyor that delivers waste to a screen that is designed to separate small fractions, and then through a sorting conveyor with a platform for selecting recyclable components, a chain conveyor for feeding the unused dispersed part of the waste to the grinder 2 , a conveyor for feeding recyclable components to the presses with subsequent packaging, a separator for separating metal, a packaging press (AL 50) for metal, a packaging press (LP80VH2) for paper, plastic, rags, etc.

 The recyclable components are recovered, and the recyclable mass is: food waste, mineral constituents, small fractions of the recyclable components mentioned above, not separated during the sorting process, construction, industrial and household waste, various organic waste of plant and animal origin, etc. enter the chopper 2, in a specific example, a rotary knife with a built-in hammer section grinding. Waste grinding is carried out to a level of particles with sizes above 10-15 mm not more than 10% of the total mass of ground waste. The separation of the crushed mass into fractions is performed on vibrating screens of the SMK 32d type.

 The ground mass enters the mixer 3, in a specific example, a twin-shaft, continuous type SMK 126. The paste preparation unit 4 is also a forced action mixer. It receives mineral components and water in a ratio of 1: 1 to 1-2. In the dosing unit 5 of the bunker type, water paste prepared in block 4 and activated sludge are supplied. From block 5, the necessary amount of paste and sludge enters, together with the crushed mass of waste, into the mixer 3.

 In the mixer 3 is the neutralization of the crushed mass of waste as a result of homogenization of all components received in the mixer. In this case, the process of alkaline hydrolysis of various pollutants, organic and mineral, contained in the crushed waste; pollutants (heavy metals, pathogenic microflora, toxic hydrocarbons, etc.) are combined with the sol-gel phase of the mineral aluminosilicate matrix; pollutants form all kinds of environmentally friendly complex compounds, depriving pollutants of migratory ability and toxic effects. From the mixer 3, the treated mass enters the extruder 6.

 The extruder 6, an aggregate screw type SMK 482A, has a cylindrical body with a screw located in it. The output part of the extruder is a conical confuser with nozzles of various output sections. The treated mass is fed by a screw into the confuser, while it is additionally mixed and heated during compaction to a predetermined density. The obtained compacted material is a tape, which is then cut into individual briquettes of a given size. Briquettes are packaged in plastic bags in block 7 packaging briquettes. Pre-packaged briquettes acquire the required strength after 5-7 days, after which they can be used as a building material in the construction of foundations of various designs or can be laid in the body of the technogenic array.

 The equipment used to implement the claimed method can be permanently installed in the factory or installed on several mobile platforms that form a single mobile technological complex.

 The implementation of the method is illustrated by the following examples. In all examples, solid waste from the South dump near the Volkhonskoye Highway in the Leningrad Region was subjected to neutralization. The technology described above was applied at various ratios of components.

Example 1. The aqueous paste contained the following components, wt.%, In a ratio with water 1: 2:
Dispersed aluminosilicates - 75
Portland cement - 5
Ground quicklime - 10
Semi-aquatic gypsum - 8
Calcium Chloride - 1.5
Ferric Chloride - 0.5
Example 2. A water paste contained the following components, wt.%, In a ratio with water 1: 1,5:
Dispersed aluminosilicates - 70
Portland cement - 5
Ground quicklime - 15
Phosphogypsum - 8.8
Magnesium Chloride - 1
Ferric Chloride - 0.2
Active sludge was additionally fed into the mixer in a ratio of 0.25: 1 to the total weight of the above dry components of the aqueous paste.

Example 3. The aqueous paste contained the following components, wt.%, In a ratio with water 1: 1:
Dispersed aluminosilicates - 47
Portland cement - 25
Ground quicklime - 10
Phosphogypsum - 15
Calcium Chloride - 2
Ferric Chloride - 1
Activated sludge was additionally fed into the mixer in a ratio of 0.5: 1 to the total weight of the above dry components of the aqueous paste.

 The results of the implementation of the method according to examples 1, 2, 3 are shown respectively in table. 1, 2, 3.

 To implement the method used available chemicals and conventional equipment, which determines the compliance of the invention with the criterion of "industrial applicability".

Claims (5)

1. The method of disposal of solid waste, including grinding and processing in a mixer, which also serves as a binder solution, characterized in that as a binder use an aqueous paste containing the following components in a ratio of 1: 1-2 with water, wt. %:
Dispersed aluminosilicates - 40-75
Portland cement - 5-25
Quicklime, ground - 5-15
Semi-aquatic gypsum or phosphogypsum - 5-15
Alkaline earth metal chloride - 1-2
Ferric Chloride - 0.2-1
and the mass processed in the mixer is heated and compacted by passing it through an extruder.  2. The method of neutralizing solid waste according to claim 1, characterized in that the sludge is additionally supplied with activated sludge in a ratio of 0.2-0.5: 1 to the total weight of dry components of the aqueous paste.  3. A method for the disposal of solid waste according to claim 1 or 2, characterized in that the waste is ground to a particle content of more than 10-15 mm in size not more than 10% of the total mass of ground waste.  4. The method of disposal of solid waste according to any one of paragraphs. 1, 2 or 3, characterized in that after extrusion of the resulting mass is packaged in a sealed container.  5. A method for the disposal of solid waste according to claim 4, characterized in that plastic bags are used as sealed containers.

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