Method of producing glassceramic material

FIELD: chemistry.

SUBSTANCE: method relates to production of construction materials, particularly to use of ash from refuse incineration plants for processing solid domestic wastes, followed by recycling thereof in production of highly efficient and environmentally safe construction articles. The method is characterised by that glass mass is obtained from a mixture containing up to 70% ash, 20-40% silica-containing component and up to 20% alkali-containing component. The obtained articles undergo crystallisation in a single step at temperature 900-1100°C and holding for 60-120 minutes or in two steps at temperature 700-850°C and holding for 30-60 minutes and at temperature 900-1100°C for 60-120 minutes.

EFFECT: high chemical resistance, wear resistance, prevention of water absorption and environmental safety of the obtained glassceramic material.

4 cl, 1 tbl, 3 ex

The invention relates to methods of producing glass-ceramic material comprising sifting the ash resulting from combustion of solid waste, dosage, mixing with alkali - and silica-containing components, heat treatment before the formation of glass, molding and annealing, characterized in that the glass melt is obtained from the blend containing up to 70% fly ash, silica component 20-40%, seocndary component to 20%. The obtained product is subjected to crystallization in a single phase at a temperature of 900-1100°C with a holding time of 60 to 120 minutes or in two stages at a temperature of 700-850°C aged 30-60 minutes and 900-1100°C for 60-120 minutes.

The known method of disposal of ashes, including mixing 40-60% of the mass. ash 10-20% of the mass. component-based Si dioxide, the formation of granules on the basis of the obtained mixture, dusting them dispersed refractory material, heat treatment of the granules in two stages: the first stage for 10-30 minutes at T=400-600°C, the second for 1-20 minutes at T=870-950°C [1]. The disadvantage is the limitation of the ash content in the raw material mixture, introducing the mixture 5 additional components, the lack of data on the ecological purity of the obtained material and its properties.

Also known is the closest to the proposed solution to the technical essence and the achieved result of the way the floor is ing glass-ceramic material by preparing the mixture, heat the glass by using a plasma coolant, molding, crystallization and annealing, characterized in that for the purpose of process intensification and expansion of raw materials heat up to 1600-2000°C lead with a speed of 10³-10⁴deg/hour [2].

The disadvantage is the high water absorption of the obtained material, which further leads to deterioration of performance characteristics and the lack of data on its environmental friendliness. The technical result of the invention to provide a glass-ceramic material having a high chemical resistance, wear resistance, lack of water and environmental security.

The delivered result is achieved by the fact that the glass-ceramic material is obtained from the ash resulting from incineration of municipal solid waste with subsequent prozivom, dosage, mixing with alkali - and silica-containing components. Environmental cleanliness is ensured by high chemical stability and absence of water absorption of the obtained material.

The molding is performed by pressing, continuous Bicycle or centrifugal casting. The crystallization is carried out in one stage at a temperature of 900-1100°C for 60-120 minutes or in two stages at a temperature of 700-850°C aged 30-60 minutes and 900-1100°C for 60-120 minutes. When dealing in charge of introducing the additive is a catalyst in the amount of 0.5 to 10.0 wt.%.

When developing products by rolling molten glass is formed into rolling machines in a continuous ribbon width 1200-1300 mm, a thickness of 8-20 mm Tape serves in gas or electric tunnel oven, where crystallization occurs. Then the tape is subjected to annealing, cooling and cutting into sheets of a given size.

By pressing on automatic presses are made of tiles of size 125×300×15 mm, which are then subjected to crystallization annealing and cooling.

In centrifugal casting in a rotating form fill glass melt, which under the action of centrifugal force pressed against the walls and freezing, takes the desired form.

Catalysate is the additional heat treatment, resulting in the transition of the glassy state in the glass. Upon completion of the process material, comprising 60-70% of the crystal with a crystal size of 0.1-1.5 μm and 30-40 glassy.

The sizes of eye-catching crystals, their composition and quantity of regulated regime of heat treatment and determine the basic properties of the material. Mode selection crystallization is carried out by analyzing the DTA original glass. The presence of ash several catalysts crystallization (sulphides, oxides of chromium and phosphorus) can not only speed up the process of separation of the phases, but also to change alternately, the th selection, qualitative and quantitative relationships. The presence of ash from incineration of oxides of Cr₂O₃sulphides, phosphates, are effective catalysts for satellitario does not require, in most cases, the introduction of catalytic additives in the composition of the charge on the basis of incineration ash. Significant fluctuations of the composition of the ash requires adjustment amount is added to the mixture silica and deletestream components. The resulting satellitario new glass-ceramic materials are monolithic composites, consisting of fine-grained crystals and evenly distributed between the glass rim. A distinctive feature of glass-ceramic materials - fine multifasta structure, which implies a significant improvement in their performance characteristics.

Temperature resistance, wear resistance, acid and alkali, no water absorption, all of these indicators provide a high resistance glass-ceramic material under operating conditions, preventing the escape of products of toxic compounds in the environment. Products are non-toxic and is not subject to destruction under the influence of the atmosphere.

Increased environmental clean glass-ceramic materials based on fly ash MRZ provides a high position is coordinating a number of heavy metal ions, determining their location in three-dimensional tetrahedral si grid.

When testing the used sodium sulfate, silica sand with the content of SiO₂up to 99% of the mass. and ash MRZ three compounds presented in the table.

The following are specific examples of the glass-ceramic material obtained by the proposed method.

Example 1.

The ash composition 1 (see table) sieved through a sieve of 0.7, dosed by weight 55% of the mixture, mixed with kremnezemistye and delicatessa 40 and 5%, respectively, compacted and heated to a temperature of 1550°C, can withstand 1.5-2 hours to obtain a homogeneous molten glass is cooled to 1000°C. is Formed by extrusion and subjected to crystallization by single-stage mode with the shutter speed at a temperature of 900°C for 120 minutes and annealed. The obtained products are characterized by the following indicators:

- the tensile strength of 85 MPa;

- operating temperature - 180°C;

- CTLR, α·10⁷deg^-7- 90;

- T_{ad size}- 850°C;

- abrasion g/cm²- 0,025;

- acid (H₂SO₄)% - 95;

- mesocestoides NaOH % - 80;

- water absorption - 0.

Example 2.

The ash composition 2 sift through a sieve of 0.7, dosed by weight in the amount of 65% of the mixture, mixed with kremnezemistye in the amount of 30% and delicatessa the amount of 5%, condense in the form of pellets and heated to a temperature of 1560°C, incubated for 1.5 hours to obtain a homogeneous glass melt, cooled to a temperature of 1050°C and formed into a continuous ribbon and put satellitario in the oven-the mould in two-step mode with a shutter speed of 60 minutes at 800°C and at a temperature of 920°C for 90 minutes, then annealed. The obtained products are characterized by the following indicators:

- tensile strength of 95 MPa;

- operating temperature - 25°C;

- CTLR, α·10^-7deg^-7- 80;

- T_nrsm- 800°C;

- abrasion g/cm²at 0.020;

- acid % (H₂SO₄) - 98;

- alkali % (NaOH) - 85;

- water absorption - 0.

Example 3.

The ash composition 3 sieved through sieve 0.7, dosed by weight in the amount of 72% of the mixture, mixed with kremnezemistye in the amount of 24% and delicatessa 4%, condense in the form of briquettes, is heated to T=1560°C, can withstand 90-120 minutes, cooled to a temperature of 1000°C and formed into a continuous ribbon, then subjected to heat treatment in the furnace - the mould for a two-step mode with the shutter speed at T=820°C for 60 minutes and at T=900°C for 60-90 minutes. After annealing the obtained products have the following properties:

- tensile strength - 87 MPa;

- temperature resistant to 250°C;

- CTLR, α·deg^-1- 85;

- T_NRAs- 900°C;

- abrasion g/cm²- 0,022;

- acid % (H₂SO₄) - 96;

- alkali % (NaOH) - 87;

- water absorption - 0.

References

1. Patent of Russia №2123989. The method of disposal of ash.

2. Patent of Russia №2026834. A method of obtaining a glass-ceramic material.

1. A method of obtaining a glass-ceramic material comprising sifting the ash resulting from combustion of solid waste, dosage, mixing with alkali - and silica-containing components, the seal in the form of briquettes, heat treatment before the formation of the glass manufacturing process, crystallization and annealing, characterized in that the glass melt is obtained from the blend containing up to 70% fly ash, silica component 20-40%, deletestream component to 20%, the crystallization OS the effect in one stage at a temperature of 900-1100°C with a holding time of 60 to 120 min or two stages at a temperature of 700-850°C with a holding time of 30-60 min and 900-1100°C for 60-120 minutes

2. The method according to claim 1, wherein the product is formed by pressing.

3. The method according to claim 1, wherein the product is formed into a continuous distribution.

4. The method according to claim 1, wherein the product is formed by centrifugal casting.