LT5877B - Material based on phosphogypsum for construction elements, process for production thereof and uses thereof - Google Patents

Abstract

New material for construction elements based on phosphogypsum consists of Portland cement, pozzolonic constituent and special additives. A process for production of construction elements from that material for use in building special constructions such as wind power stations, constructions in the sea, constructions in the rivers, chimneys and flue-gas stacks is also claimed.

Description

Phosphogypsum is often used as a component in various building materials.

There is a known process for converting phosphogypsum into mineral aggregates (LT 4440), where phosphogypsum, after successive sophisticated technological operations, produces a finished product with special properties that is intended to replace natural chalk and is therefore used in other construction products, namely mineral aggregates.

The disadvantages of this technique are the complexity of the technology, the large number of equipment used, the high cost of equipment and energy (combustion at 450-500 ° C).

An anhydrite binder composition (LT 4050) is known, where construction materials require an operation at 850-950 ° C to achieve the required mechanical properties (for example, compressive strength of 50-70 MPa). Using this method of preparing an anhydrite binder composition does not result in high energy costs.

There is a known method of preparing gypsum binder (LT 4699) by neutralizing the production waste phosphogypsum in a hot lime milk suspension, further filtering the dried pulp, drying and grinding or simply thickening it into ready-made molds. The disadvantages of this method are the complex manufacturing technology and the insufficient strength of special purpose buildings. In the known manner, strengths of up to 18 MPa (up to 183.5 MPa) are achieved

A kgf / cm) at 24 h. from the formation of the material.

The common disadvantage of all of the above examples is the relatively low processing capacity of the phosphogypsum, the relatively complex technology and the high energy consumption.

The closest proposed technical solution is described by S. Gaiduci (Gaiduci, Sergei. 2010. Effect of Mechanical Activation and Additives on the Properties of Extracted Potassium Phosphogypsum and Its Products. Doctoral Dissertation, p. 134). This scientific source describes a phosphogypsum-based material for structural elements, containing 20% Portland cement and 10-20% pozzolanic additive, and a method for manufacturing structural elements from this material, which comprises dosing and mixing the components. An analogue method of mechanical activation in the manufacture of articles from said substance is proposed and tested.

Specimens formed from such material exhibited a dense water absorption of 1670-1790 kg / m ^{3 at a} level of 5.9-7.4% and a compressive strength of 35-42 MPa.

The state of the art does not guarantee the applicability of the material to special purpose buildings.

It is an object of the present invention to provide a composition of extruded push-pull phosphogypsum with special additives, and to provide a method that allows the construction of structural elements of the required strength for use in the construction of special purpose buildings with reduced energy consumption.

This object is achieved by the totality of the features of claims 1-9 of the invention.

The present invention relates to a phosphogypsum-based material for structural elements with a Portland cement and a pozzolanic additive. The material is distinguished by the addition of plastic and the ratio of components (% w / w) is as follows:

Main components:

Extract Pyrhydric Phosphogips - 60-70;

portland cement - 15-20;

pozzolanic supplement - 10-25;

Additive Components:

Plastic - 0.5 - 2.0, where the amount of plastic is calculated based on the amount of the main components.

Another proposed material for building elements based on phosphogypsum, which has Portland cement and a pozzolanic additive, is distinguished by the addition of a plasticizer and curing agent at the following component ratio (w / w):

Main components:

Extract Pyrhydric Phosphogips - 60-70;

portland cement - 15-20;

pozzolanic supplement - 10-25;

Additive Components:

In plasticizer - 0.5-2.0;

Cure regulator - 0.5-2.0, where the amount of plasticizer and cure regulator is calculated with respect to the content of the main components.

According to the present invention, the pozzolanic additive of building material materials based on phosphogypsum is opaque and the plasticizer is selected from the group consisting of MIKS, MURAPLAST, monoethanolamine, STACHEPLAST 125, POZZOLITH STANDARD and others.

The phosphogypsum-based curing regulator for building material materials is selected from the group consisting of D-2, lignosulfonate regulators, casein, sodium fluoride, sodium tripolyphosphate, carpentactane production wastes, latex or other binding process regulators.

Another object of the invention is a method of manufacturing structural elements from the aforesaid material comprising dosing the components and mixing the main components with additives, whereby the extruded phosphate gypsum is taken as a waste from the phosphate fertilizer before being cooled mechanically and reinforcement is incorporated by mechanical or manual compaction of the mixture into molds.

In the present process, the unheated hot extractive phosphate phosphate as a waste from phosphate fertilizer production is 60-68 ° C.

The mixture is mechanically activated by a disintegrator at 3000-6000 rpm of the activating discs.

Another object of the invention is the use of structural elements obtained in the proposed manner for special purpose structures such as wind turbines, offshore structures, river structures, smoke and steam chimneys.

The following table provides examples of the invention material, which illustrates but does not limit the scope of the invention.

Table 1

Examples of composition of the inventive material and properties of the resulting products.

For example .. No. Composition,% by weight Composition,% by weight the amount of composition Density, kg / m3 Water absorption,% Compression strength, MPa Extractive pushidratis phosphogypsum Portland cement Pucolan inis Annex (carbon athlete opoka) Plastic add WHY Hardening regulators us D-2 1 60 15th 25th 0.5 0 2000- 2100 5.0-7.0 42-47 2 60 20th 20th 2.0 1.0 2100- 2200 2.0-4.0 48-54 3 70 20th 10th 2.0 0.5 2000- 2100 2.0-5.0 45-50 4 70 20th 10th 1.5 1.5 2200- 2300 2.0-5.0 50-55 5 70 15th 15th 1.0 2.0 2200- 2300 2.0-3.0 52-57

An example of an embodiment of a method for manufacturing building elements from a material of the invention is:

(1) rapidly removing the non-cooled hot extraction phosphate gypsum phosphate (having a humidity of 30%, temperature 65 ° C, pH 2.5) from the waste conveyor in a blender to obtain the composition of Example 4 in Table 1;

(2) the resulting mixture was mechanically activated by a mechanical activation device disintegrator (GORIZONT -1500 SD, DIM 800K), where the activating discs were rotated at 5000 rpm.

(3) pouring the activated mixture into ready-made molds containing a welded reinforcement shell;

(4) The mixture is molded by vibrators for 12-15 minutes, or manually compacted to form a cured product.

Conventional serial production equipment such as belt conveyor, mixer, disintegrator, hand-held vibrators are used.

Advantages of the proposed technical solution:

In the present invention, energy consumption is significantly reduced by requiring 14 times lower temperature (compared to process described in LT 4050), within the range of 60-68 ° C, which does not require special maintenance during the process, and by comparison with low strength material based on LT4699. compressive strength of construction material for special purpose buildings up to 55 MPa.

Mechanical activation of the phosphogypsum appears to have a positive effect on the stability of the properties of the resulting material, in addition to increasing the compressive strength of the specimens.

Due to the properties of Portland cement in combination with other components of the inventive material, the hardened product is made more water resistant.

In addition, special additives added to the phosphogypsum molding compound substantially or partially alter the properties of the molding compound and the resulting material so that the structural elements produced by the present invention become capable of withstanding dynamic loads in an aggressive environment.

In the present invention, additives increase the strength of the material, reduce water absorption, and stabilize the binding time of the ingredients

The composition of extruded push-pull phosphogypsum with the specified composition is used for the production of special-purpose building elements such as wind turbines, marine structures, river structures, smoke and steam chimneys and the like.

In Table 1, the compositions designated by Nos. 1 and 3 are used in the fabrication of elements of wind turbine structures. Material No. 2 is used for the production of elements of wind turbine structures and elements of waterproof structures. Material No. 4 is used for the production of elements of waterproof structures.

All of the compositions in Table 1 (Nos. 1, 2, 3 and 4) are used in the manufacture of smoke and steam chimney structural members.

Composition No.5 is used for the construction of wind turbine structures.

The tests performed confirm the expediency of the structural elements of the declared material, the method of their manufacture and their use in the production of structural elements of the structures. The products are of optimum strength, durable, resistant to dynamic loads in an aggressive environment, ecologically clean, and utilize phosphate fertilizer production waste. In addition, the composition of the claimed material is such that it protects the reinforcement of the elements of the resulting building structures from the adverse effects of the aggressive environment.

The method of manufacturing the structural material from the claimed material does not require high energy consumption, the production is waste-free, and the phosphate fertilizer production waste is utilized in the production process, as well as conventional serial production equipment is used in the production process.

Claims (9)

DEFINITION OF INVENTION 1. Material of building elements based on phosphogypsum, containing Portland cement and pozzolanic additive, characterized in that it additionally contains plastic in the following proportion by weight (% by weight): Main components: Extract Pyrhydric Phosphogips - 60-70; portland cement -15-20; pozzolanic supplement - 10-25; Additive Components: Plastic - 0.5 - 2.0, where the amount of plastic is calculated based on the amount of the main components. 2.Phosphogypsum based building material material, containing Portland cement and pozzolanic additive, characterized in that it additionally contains a plasticizer and a curing agent in the following proportion by weight (% by weight): Main components: Extract Pyrhydric Phosphogips - 60-70; portland cement - 15-20; pozzolanic supplement - 10-25; Additive Components: In plasticizer - 0.5-2.0; Hardener regulator - 0.5-2.0, where the amount of plasticizer and hardener is calculated in terms of the content of the main components. The building element material of phosphogypsum according to claim 1 or 2, wherein the pozzolanic additive is a carbonate opacifier and the plasticizer is selected from the group consisting of MIKS, MURAPLAST, monoethanolamine, STACHEPLAST 125 and POZZOLITH STANDARD. The building material building material based on phosphogypsum according to claim 3 wherein the curing regulator is selected from the group consisting of D-2, lignosulfonate regulator, casein, sodium fluoride, sodium tripolyphosphate, carpolactam production waste and latex. 5. A method of manufacturing structural elements from a material according to any one of claims 1 to 4, comprising dosing the components and mixing the main components with additives, characterized in that the extraction of the extruded phosphate gypsum as a phosphate fertilizer waste is mechanically activated and pouring the activated mixture into molds containing reinforcement by mechanical or manual compaction of the mixture into the molds. 6. A process according to claim 5, wherein the non-cooled hot extraction phosphate phosphate as a phosphate fertilizer waste is at a temperature of 60-68 ° C. 7. A method according to claim 5 or 6, wherein the mechanical activation of the mixture is performed by a disintegrator at a speed of 30006000 rpm of the oiling discs. Use of structural elements obtained by the process according to claims 5-7 for special purpose structures. Use according to claim 8, characterized in that the special purpose buildings include wind turbines, offshore structures, river structures, smoke and steam chimneys.