GB2344341A

GB2344341A - Forming mixture and constructional material

Info

Publication number: GB2344341A
Application number: GB9928006A
Authority: GB
Inventors: Anthony Michael Psyllides
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-02
Filing date: 1999-11-29
Publication date: 2000-06-07
Also published as: GB9826315D0; GB9928006D0

Abstract

A forming mixture comprises dry, inert powder, phosphogypsum and an alkaline salt. The powder may be fly ash, pulverised rock or recycled building waste. Additives e.g. a cellulose derivative, pva resin, microfibres, a starch ether, a water repelling agent, colour or flame-retardant, may be included. An aerating agent e.g. a carbonate may be added to yield thermally insulating materials.

Description

FORMING COMPOUND AND CONSTRUCTIONAL MATERIAL This invention relates to forming compounds and constructional materials.

It is known to utilise fly ash-waste from coal-fired power stations-in admixtures with various other materials to make building products such as breeze block or breeze brick, and as a filler in materials such as reclaimed-plastics mouldings extrusions. Fly ash being light in weight and befitting its name-ash that flies-is difficult to handle and is used principally in the large scale manufacture of finished articles.

The present invention provides a forming compound incorporating a fly ash or other dry, inert powder that can be used as the basis of a range of constructional materials with predeterminable properties.

The invention comprises a forming compound comprising dry, inert powder, phosphogypsum and an alkaline salt.

The dry, inert powder may comprise fly-ash, or other residual ash, pulverised rock or recycled building waste.

The inert, dry powder may be a major proportion by weight and may comprise 65-85%, preferably 70-80%, preferably 74-76% by weight of the compound.

The alkaline salt-which may be of any convenient metal and so may also be an industrial waste or by-product-may comprise 0.2-1.0%, preferably 0.4-0.6% by weight of the compound.

It will be appreciated that the term"compound"is used here not in the strict chemical sense, rather in the sense of a mixture of ingredients much as a rubber compound is a mixture of ingredients prepared for making a rubber.

It is found that the compounds of the invention yield formed artefacts that are in most respects at least equal to and often better than clay, cement or gypsum-based products. This may be due at least in part to a laminating effect noticed when using the compounds. In addition, by means of functional additives a wide range of constructional materials can be provided.

A cellulose derivative may be added, for example in amounts 0.1-0. 3% by weight of the material.

The additive may comprise a bond agent such as a combination of PVA polymer resins, for example in amounts 0.5-4% by weight of the material.

Microfibres may be added in amounts, for example, 1-15% by volume of the material; starch ether, for example in amounts 0.1-0.3% by weight of the material ; and a water repellant may be added in amounts, for example, of 2-6% by weight.

Colour, for example dispersable powder colouring, may be added to the material in such amounts as will yield a desired depth of shade. On the other hand, products made using the compounds or the constructional materials may be painted.

The invention also comprises artefacts made from the forming compounds or constructional materials of the invention.

The invention makes effective use of by-products or waste products, fly-ash being the by-product of coal burning, other residual ashes being the by-product of burning other materials, pulverised rock being a by-product of stone quarrying and recycled building materials being a waste product of low value used for hardcore.

Phosphogypsym is a by-product of phosphate fertiliser manufacturing and alkaline metal salts is by-products of cellulose production. Thus the invention not only provides inexpensive, new and useful materials with desirable properties, it also solves a utilisation/disposal problem for by-products or waste produce which are available in large quantities. At least 85% of the forming compound or of artefacts made therefrom can comprise One particularly beneficial property of products made using the compounds of the invention is enhanced fire resistance as compared to clay, cement or gypsum based fly-ash products. Products made according to the invention are also acid-resistant.

By way of Example, the following Table lists a variety of constructional materials based on Compound comprising, by weight: fly-ash 75% phosphogypsum 24.5% alkaline salt 0.5% Constituents Properties Applications 99.5-99.8% Compound Fireproof. Interior joint filler.

0.2% Cellulose derivatives Plastic. Minor plaster repairs. up to 0.3 % PVA resins Crack resistant.

Quicksetting.

97.8-98.8% Compound Fireproof. Interior/exterior 0.2% Cellulose derivatives Water-resistant. joint filler.

1-2% PVA resin Plastic. Major plaster Quicksetting. repairs.

Crack resistant.

96.7-98.7% Compound Fireproof. All purpose all 0. 3% Cellulose derivatives Water-resistant. weather plastering and 1-3% PVA resin Plastic. rendering compound.

10% by volume microfibres Quicksetting.

Crack resistant.

Flexural strength.

High workability 96.7-98% Compound Fireproof. All purpose mortar 0.3% Cellulose derivatives Water-resistant. compound.

1-7-3% PVA bond resins Plastic.

Quicksetting.

Crack resistant.

Flexural strength.

High workability.

Highly adhesive.

99.2-99.4% Compound Fireproof. Manufacture of light 0.1% Cellulose derivatives Lightweight. aggregate for making 0.5% PVA resins Quicksetting. lightweight concrete. up to 0.2% carbonate or Optionally aerated. Insulating screeds. bicarbonate for aeration Coving and decorative panels.

92.6-93.6% Compound Fireproof. Moulding and extruding of bricks, 0.2% Cellulose derivatives Water-repellant Roofing tiles, 0.2% Starch ether Plastic, Acoustic tiles, 3% PVA resins Quicksetting, crack Precast fencing, 4% Water repelling agent resistant Flower pots/basins. up to 3% by volume microfibres Flexural strength. Casting of garden High workability ornaments, etc.

High adhesive strength High compression strength Shatter resistant.

95.6% Compound Fireproof Manufacture of 0.2% Cellulose derivatives Water-resistant partitioning boards, 4% PVA resins Quicksetting. Crack Fire barriers, 10% by volume microfibres resistant ceiling panels for Flexural Strength. interior use.

High workability High adhesive strength High compression strength.

Shatter resistant.

88.6-92.6% Compound Fireproof Manufacture of 0.2% Cellulose derivatives Water-repellant partitioning boards, 0.2% Starch ether Plastic, Fire barriers, 3% PVA resins Quicksetting. Crack ceiling panels, up to 4% Water repelling agent resistant Corrugated sheets etc 10% by volume microfibres Flexural strength. for exterior up to 3% anti-pyretic High workability applications compounds High adhesive strength High compression and tensile strength.

Shatter resistant All of these materials can be mixed dry, for packaging, and water added at point of use to achieve an appropriate consistency for crack-filling, moulding or whatever. Colour, in the form of dispersable powder pigment, may be added to the dry or to the wet mix or uncoloured artefacts may be painted using household or industrial paints suitable for painting plaster or concrete.

Thermal insulation blocks or panels may be made with the addition of an aerating agent such as a carbonate.

Variations in mechanical properties can be achieved by varying the relative proportions of ingredients and by varying the types, amounts and combinations of functional additives.

Claims

CLAIMS 1. A forming compound comprising dry, inert powder, phosphogypsum and an alkaline salt.
2. A forming compound according to claim 1, in which the dry, inert powder comprises ash.
3. A forming compound according to claim 2, in which the dry, inert powder comprises fly-ash.
4. A forming compound according to any one of claims 1 to 3, in which the dry, inert powder comprises pulverised rock.
5. A forming compound according to any one of claims 1 to 4, in which the dry, inert powder comprised recycled building waste.
6. A forming compound according to any one of claims 1 to 4, in which the dry, inert powder comprises 65-85% by weight.
7. A forming compound according to claim 6, in which the inert, dry powder comprises 70-80% by weight.
8. A forming compound according to claim 7, in which the inert, dry powder comprises 74-76% by weight.
9. A forming compound according to any one of claims 1 to 8, in which the alkaline salt comprises 0.2-1.0% by weight.
10. A forming compound according to claim 9, in which the alkaline salt comprises 0.4-0.6% by weight.
11. A forming compound according to any one of claims 1 to 10, of which the constituents comprise at least 85% by-products.
12. A constructional material comprising a forming compound according to any one of claims 1 to 11 together with a functional additive.
13. A material according to claim 12, in which the additive comprises a cellulose derivative.
14. A material according to claim 13, in which the cellulose derivative and amounts to 0.1-0.3% by weight.
15. A material according to any one of claims 12 to 14, in which the additive comprises a bond agent.
16. A material according to claim 15, in which the bond agent comprises PVA resin.
17. A material according to claim 15 or claim 16, in which the bond agent amounts to 0.5-4% by weight.
18. A material according to any one of claims 12 to 17, in which the functional additive comprises microfibres.
19. A material according to claim 18, in which the microfibres amount to 1- 15% by volume.
20. A material according to any one of claims 12 to 19, in which the functional additive comprises starch ether.
21. A material according to claim 20, in which the starch ether amounts to 0.10.3% by weight.
22. A material according to any one of claims 12 to 21, in which the functional additive comprises a water repelling agent.

23. A material according to claim 22, in which the water repelling agent amounts to 2-6% by weight.
23. A material according to any one of claims 11 to 22, with added powder colour.
24. An artefact made from a forming compound according to any one of claims 1 to 7 or from a constructional material according to any one of claims 11 to 23.
25. Thermally insulating material made from a forming compound according to any one of claims 1 to 11 together with an aerating agent.
26. Thermally insulating material according to claim 25, comprising building blocks.