RU2753792C1 - Method for obtaining ceramic material - Google Patents

Abstract

FIELD: construction materials industry.

SUBSTANCE: invention relates to the field of construction materials technology and can be used for the production of building ceramic products. The method for producing ceramic material includes drying, grinding of clay raw materials and subsequent mixing of the components of the raw mixture, moistening until a press powder is obtained, its semi-dry pressing, drying and firing of products, pre-solid pyrolysis residue of partially sorted MSW is crushed to obtain a fine powder with a particle size of no more than 0.1 mm, low-melting clay is crushed, dried at a temperature of 80°С to a humidity of 3%, ground to obtain particles of no more than 0.1 mm, the resulting powders are mixed at the following component ratio, wt. %: solid pyrolysis residue of partially sorted MSW 20% and low-melting clay 80%, the powder mixture moistened to 10%, formed and dried at a temperature of 100°C to a humidity of 3%, and then burned at a temperature of 1000°С, the burnt powder mixture is ground, obtaining a fine thinning additive with a particle size of no more than 0.1 mm, clay raw materials, namely low-melting moderate plastic clay is ground to particles with a size of no more than 0.1 mm, the components raw material mixture are mixed at the following ratio, wt. %: low-melting moderate plastic clay 60-70% and fine thinning additive 40-30%. Partial sorting of MSW is carried out by removing plastic and polymers from them. Pyrolysis of partially sorted MSW is carried out at a temperature of 700°С.

EFFECT: production of ceramic material for the production of ceramic products that meet the National Standard requirements the expansion of the raw material base, the disposal of solid municipal waste.

3 cl, 2 tbl

Description

The invention relates to the field of building materials technology and can be used for the production of building ceramic products.

It is widely known to use industrial waste in the production of building ceramic products - various types of ash obtained as a product of fuel combustion at thermal power plants, thermal power plants, metallurgical enterprises, which not only reduces the cost of building materials, but also significantly reduces environmental pollution.

There is a method of obtaining a raw material mixture for wall ceramics ("Raw material mixture for the manufacture of wall ceramics and a method for its production" patent for invention RU No. 2500647, IPC С04В 33/132, 2013), including drying the slurry part of iron ore dressing wastes, drying and grinding of clay and cullet, their subsequent mixing, granulation, semi-dry pressing and firing of products, preparation of press powder, before pressing, the slurry part of the waste of iron ore dressing in a dry state is intensively mixed in a turbolane mixer-granulator with a part (5-10 wt.%) dry crushed clay, the mixture is moistened to molding moisture (8-12%) and granulated to obtain granules of a preferred size of 1-3 mm, which are powdered with a mixture of the remaining clay and cullet in the mixer-granulator to obtain a composition, wt. %:

Clay 10-20 Waste from iron ore dressing 70-85 Cullet 5-10

A known method of obtaining a raw mixture for wall ceramics, which can be taken as an analogue (patent for invention RU No. 2641533, IPC С04В 33/132, 2018), including drying the components, grinding the specified slag and raw materials and their subsequent mixing, granulation to obtain of the granulated press mass, its semi-dry pressing and firing of products, the specified slurry part is moistened and granulated in a turbolabed mixer-granulator to obtain granules of a preferred size of 1-3 mm at a blade rotation frequency of 20-25 s-1, followed by dusting them with a mixture clay raw materials and vanadium slag with the following ratio of components, wt. %:

Slime part of iron ore dressing wastes 80-88 Clay raw materials 10-15 Vanadium slag 2-10

The disadvantages of these methods are the complication of the technological process, the presence of an additional technological operation - granulation of the press powder, relatively low strength characteristics of the products obtained.

A known method of producing a raw mixture for decorative building ceramics containing clay raw materials (patent for invention RU No. 2701657, IPC С04В 33/132, 2019), taken as a prototype, including drying of components, grinding and their subsequent mixing, moistening and granulating raw materials in a turbolabed mixer-granulator to obtain a granular press powder, its semi-dry pressing, drying and firing of products. Moistening and granulation of clay raw materials is carried out for 2-3 minutes at a frequency of rotation of the mixer-granulator blades of 15-18 s ^-1 , after which, finely ground waste from the extraction of manganese ores is introduced with the following ratio of components, wt. %: clay raw materials 90-98; waste of manganese ore mining 2-10.

The disadvantage of this method is the presence of an additional technological operation - granulation of the press powder and the use of a relatively small amount (up to 10%) of finely ground waste from the extraction of manganese ores.

The advantage of the above technical solutions is the disposal of man-made waste, however, at present, a large volume of another type of waste is generated - this is the waste products of urban utilities in large and medium-sized cities - solid municipal waste (MSW). The approximate morphological and physicochemical composition of MSW of Russian cities located in different climatic zones is presented in Appendix 3 of the Methodological Recommendations for the Formation of Tariffs for Services for the Destruction, Utilization and Burial of Solid Waste, Moscow, 2003 (http://gostrf.com /norma_data/41/41978/index.htm). With the content of up to 70% organic (combustible) fraction in MSW, preference is given to processing by thermal methods. A promising option is the technology of pyrolysis (thermal destruction) of MSW, which allows not only to significantly reduce the amount of waste requiring disposal, but also to obtain from them alternative types of energy.

The objective of the present invention is the use of MSW disposal products in the construction industry based on the use of modern waste-free environmentally friendly technologies for MSW processing.

The technical result of the proposed invention is to obtain a ceramic material for the production of ceramic products that meet the requirements of GOST, expanding the raw material base, utilization of solid municipal waste.

The technical result is achieved by the fact that in a method for producing a ceramic material, including drying, grinding clay raw materials and subsequent mixing of the components of the raw mixture, moistening to obtain a press powder, its semi-dry pressing, drying and firing products, the preliminary solid pyrolysis residue of partially sorted MSW is crushed to obtaining a fine powder with a particle size of no more than 0.1 mm, low-melting clay is crushed, dried at a temperature of 80 ° C to a moisture content of 3%, grinded to obtain particles with a size of no more than 0.1 mm, the resulting powders are mixed with the following ratio of components, wt. %:

Solid residue of pyrolysis of partially sorted MSW twenty% Low-melting clay 80%,

moisten the powder mixture to 10%, molded and dried at a temperature of 100 ° C to a moisture content of 3%, and then fired at a temperature of 1000 ° C, grind the fired powder mixture, obtaining a finely dispersed lean additive with a particle size of no more than 0.1 mm, grinding clay raw material, which is used as a low-melting moderately plastic clay, is carried out to particles with a size of not more than 0.1 mm, the components of the raw mixture are mixed at the following ratio, wt. %:

Low-melting moderately plastic clay 60-70 Finely dispersed leaning additive 40-30

Partial sorting of MSW is carried out by removing plastic and polymers from them. Pyrolysis of partially sorted MSW is carried out at a temperature of 700 ° C.

The method for producing a ceramic material is carried out as follows.

MSW is sorted, removing plastic and polymers from them, since they are not fully suitable for pyrolysis technology. Pyrolysis of partially sorted MSW is carried out at a temperature of 700 ° C in a pyrolysis oven. Products obtained as a result of pyrolysis do not contain aggressive substances. The pyrolysis of MSW is accompanied by the formation of a gas phase (pyrolysis gas) and a carbonaceous powdery residue (solid pyrolysis residue). Pyrolysis gas can be used as an energy or energy technology fuel, and the solid residue of pyrolysis is crushed to obtain a fine powder with a particle size of no more than 0.1 mm. Low-melting clay is crushed to a lump size of 70-75 mm, dried at a temperature of 80 ° C to a moisture content of 3%, and ground until particles with a size of no more than 0.1 mm are obtained. The obtained powders are mixed in the proportion: solid residue of pyrolysis of partially sorted MSW 20% and low-melting clay 80%, with moisture up to 10% to obtain a homogeneous mixture. The moistened powder mixture is molded and dried at a temperature of 100 ° C to a moisture content of 3%, and then fired at a temperature of 1000 ° C. The fired powder mixture is ground to obtain a finely dispersed additive with a particle size of no more than 0.1 mm. The resulting finely dispersed additive is used as a softener. To obtain the raw mixture, preliminarily grind low-melting moderately plastic clay to particles no more than 0.1 mm in size, then mix it with a finely dispersed additive, at the following ratio: low-melting moderately plastic clay 60-70% and a finely dispersed additive 40-30%, the mixture is moistened to 10% to obtain a press powder.

From the obtained press powder, articles are formed at a pressure of 25 MPa with a holding time of 15 seconds, which are dried at a temperature of 100 ° C, and then fired at a temperature of 1050 ° C.

Example

To prepare a finely dispersed additive, we used partially sorted MSW of average morphological composition (without plastic), with the following ratio of components, wt. %:

Food waste 48.6 Paper and cardboard 41,7 Textile 6.9 Wood 1.4 Leather and rubber 1.4

In a pyrolysis oven, pyrolysis of partially sorted MSW of the specified composition was carried out at a temperature of 700 ° C. The resulting solid residue of pyrolysis was ground using a ball mill to obtain a fine powder with a particle size of no more than 0.1 mm. Energy dispersive analysis of the solid residue of TCR pyrolysis was carried out using an energy dispersive spectrometer based on a nitrogen-free X-Max detector (Oxford instruments) mounted on a TESCAN Vega 3SBH scanning electron microscope. The elemental composition of the solid residue of pyrolysis of partially sorted MSW of the specified composition according to the results of energy dispersive analysis is shown in Table 1. Low-melting clay with a moisture content of 20-22% was crushed using stone separating rollers to a lump size of 70-75 mm, fine grinding and drying was carried out in a tangential hammer mill of the MMT type to a moisture content of 3% and obtaining particles with a size of no more than 0.1 mm. The prepared components of the finely dispersed additive were dosed in the required quantities: the solid residue of pyrolysis of partially sorted municipal solid waste - 20%, low-melting clay - 80%, and they were mixed in a two-shaft paddle mixer until a homogeneous mixture was obtained. The powder mixture moistened to 10% was molded into briquettes on a hydraulic press at a pressure of 15 MPa and dried in a dryer at a temperature of 100 ° C to a moisture content of 3%, and then fired in an oven at a temperature of 1000 ° C. After firing, the granular material was ground to particles with a size of no more than 0.1 mm, receiving a finely dispersed additive. For the preparation of the raw material mixture, a low-melting moderately plastic clay of the montmorillonite group was used. Pre-ground low-melting moderately plastic clay with a particle size of no more than 0.1 mm and a finely dispersed additive were dosed in the required quantities, mixed and moistened to 10%. From the resulting mass, using a hydraulic press, samples were formed at a pressure of 25 MPa with a holding time of 15 seconds, which were dried at a temperature of 100 ° C, and then fired at a temperature of 1050 ° C.

After firing, the samples were tested in accordance with the requirements of the current regulatory documents. The chemical composition of the samples was determined on the basis of X-ray phase analysis on a DRON-3M diffractometer; below is the average chemical composition of the samples.

SiO ₂ - 53.7%, Al ₃ Ca _0.5 Si ₃ O ₁₁ - 21.1%, Fe ₂ O ₃ - 10.7%, CaMgSi ₂ O ₆ - 14.5%.

Table 3 shows the test results of the samples. As can be seen from table No. 3, the obtained ceramic products correspond to the guaranteed grade of Μ 200. The average density is 1740 kg / m, which corresponds to the 2nd class in terms of the average density of the product (GOST 530-2012).

Thus, the use of the proposed method makes it possible to obtain building ceramic products that meet the requirements of GOST, expand the raw material base and dispose of solid municipal waste.

Claims (6)

1. A method of obtaining a ceramic material, including drying, grinding clay raw materials and subsequent mixing of the components of the raw mixture, moistening to obtain a press powder, its semi-dry pressing, drying and firing of products, characterized in that the preliminary solid pyrolysis residue is partially sorted solid communal waste (MSW) is crushed to obtain a fine powder with a particle size of no more than 0.1 mm, low-melting clay is crushed, dried at a temperature of 80 ° C to a moisture content of 3%, grind to obtain particles with a size of no more than 0.1 mm, the resulting powders are mixed at the following ratio of components, wt. %: Solid residue of pyrolysis of partially sorted MSW twenty Low-melting clay 80; moisten the powder mixture to 10%, molded and dried at a temperature of 100 ° C to a moisture content of 3%, and then fired at a temperature of 1000 ° C, grind the fired powder mixture, obtaining a finely dispersed lean additive with a particle size of no more than 0.1 mm, grinding clay raw material, which is used as a low-melting moderately plastic clay, is carried out to particles with a size of not more than 0.1 mm, the components of the raw mixture are mixed at the following ratio, wt. %: Low-melting moderately plastic clay 60-70 Finely dispersed leaning additive 40-30 2. A method for producing a ceramic material according to claim 1, characterized in that partial sorting of MSW is carried out by removing plastic and polymers from them. 3. A method for producing a ceramic material according to claim 1, characterized in that the pyrolysis of partially sorted MSW is carried out at a temperature of 700 ° C.