WO2001079378A1

WO2001079378A1 - Collecting material

Info

Publication number: WO2001079378A1
Application number: PCT/GB2001/001734
Authority: WO
Inventors: David John Johnson
Original assignee: David John Johnson
Priority date: 2000-04-18
Filing date: 2001-04-17
Publication date: 2001-10-25
Also published as: GB0009421D0; AU4858301A

Abstract

A material for collecting oils, fuels, greases and other chemicals for instance when spilled on a surface. The material including a non-oil resistant rubber powder, the particles of which have dimensions in substantially all directions lying within the range 0.1mm - 0.8mm. The rubber powder may be produced from recycled material.

Description

Collecting Material

The present invention concerns improvements in or relating to collecting materials, and especially but not exclusively materials for collecting oils, fuels, greases and certain chemicals, for instance when spilled on a surface.

In this specification the term "rubber" is intended to embrace natural rubber and synthetic rubber.

According to the present invention there is provided a collecting material including a rubber powder, the particles of which have dimensions in substantially all directions, lying within the range 0.1mm - 0.8mm, the rubber being non-oil resistant.

Preferably the rubber of the collecting material is natural rubber and/or non-oil resistant synthetic rubber.

Preferably the rubber powder is made from recycled material, which material may be produced by a devulcanisation depolymerisation process.

Alternatively, new rubber may be used, which may be virgin or off specification.

Preferably the rubber powder is mixed with mineral materials, for example, crushed stone or gas concrete, pulverised coal, clays, sand, calcium carbonate, barium sulphate, aluminium silicate, mineral fibres, wood flour, sawdust, natural and synthetic fibres.

Preferably an anti-slip additive is added to the powder.

Preferably the powder is one or more of 16, 20, 30, 40 or 50 mesh size.

The collecting material may be contained by a permeable member, which member may be made of fabric or plastics material, and may be in the form of a sheet, sleeve, sock or envelope.

Embodiments of the present invention will now be described by way of example only.

The invention provides a material for collecting spilled oils, fuels, grease and certain chemicals/liquids from, for example, floors and garages, factories, workshops, filling stations, kitchens and at the scene of road accidents. These materials may be collected by one or more of absorption, adsorption or binding with the collecting material. The collecting material comprises a rubber powder made predominantly from scrap tyres from which the steel cord reinforcement has been removed. The scrap consists of tread rubber and the remaining part of the tyre casing, as well as the synthetic reinforcing material of the tyre. Sources of recycled rubber other than tyres, for example conveyor belts, profiles, mouldings, etc. can be used.

The recycled material, which is predominantly natural rubber (NR) may also include non-oil resistant synthetic rubber, for example styrene butadiene rubber (SBR), butyl rubber (IIR), polyisoprerie (IR) or polybutadiene (BR).

The recycled rubber is processed by any suitable known process, such as devulcanisation depolymerisation, to provide a powder, that is a collection of processed rubber particles, with dimensions in the range 0.1mm - 0.8mm.

it would also be possible to partially or wholly use non-oil resistant synthetic rubber, or new rubber. The latter may be virgin or off specification, i.e. rubber contaminated perhaps at the plantation.

The volume of air present in a known weight of rubber powder according to the invention, compared with a known weight of rubber particles for instance in the form of chips, strips, flakes and crumbs, in certain circumstances would have a reduced capillary action capable of absorbing oil, etc. The capillary rise of oil to be absorbed by the collecting material of the present invention is high due to the relatively low surface tension of oil, so that oil is sucked up instantly by the collecting material like paraffin in the wick of a lamp. The oil then penetrates and is absorbed into the rubber powder due to the large available surface area of the rubber powder so that an almost dry oil/rubber mass remains after a few days.

The handling and disposal of such a mass of virtually dry rubber particles is much easier than the disposal of a very oily mass when the rubber particles are not oil absorbent. The present invention observes that the smaller the particle size of the powder the larger the total surface area available for absorption, adsorption or penetration. The surface area of the particles also depends on the method employed when the scrap rubber is size reduced. The absorption capacities for oils, fuels, greases and certain chemicals/liquids of a fixed amount of rubber does not increase with the total surface area but the oil is absorbed much faster when the size of the particles is reduced and a larger surface area is available.

Conventional oil absorbents are based on granules made of mineral materials, for example clays, calcium, carbonate, calcinated aluminium silicate, titanium dioxide and other materials such as cellulose fibres. The absorption capacity of these conventional granules is limited and the disposal of mineral granules containing oil presents problems to the environment. In addition the winning of these materials has a detrimental effect on the landscape. Additionally certain chemicals used to remove spilled oils are environmentally hazardous, for example cellulose fibres are a fire hazard. Rubbers do not present a hazard to the environment.

In the collecting material of the present invention, additional materials may be added to the rubber powder in order to improve the effectiveness of the absorption, adsorption or binding and/or in order to increase the bulk density for certain applications. Such additives could be mineral materials for example crushed stone or gas concrete, pulverised coal, clays, sand, calcium carbonate, barium sulphate, aluminium silicate, mineral fibres. Additionally or alternatively, in order to lower the bulk density, materials like wood flour, sawdust and certain natural and synthetic fibres could be added. Further additionally or alternatively, to enhance the non-slip properties of the collecting material, other appropriate additives may be included.

In use, the collecting material is normally scattered on the spilled oil, etc. to be bound in and absorbed, but it can be applied to areas where oil leakage is anticipated, and if it is preferable to contain the collecting material in these uses, it can be contained within a fabric sleeve or sock arrangement. Such sleeves can be installed around machine frames where oil leakage is anticipated. The collecting material may also be contained in a flat fabric envelope to form a blanket. Alternatively, a permeable sheet may simply be placed on the oil, and the material placed on the sheet. Such arrangements should have an open mesh or porous material such that the oil to be absorbed will soak through the structure and into the rubber powder absorbent/binder. Woven and non-woven fabric or appropriate natural and synthetic material would be suitable for the manufacture of such arrangements.

It is to be realised that the powder formation of the collecting material described with reference to the above embodiment has an absorption capacity of some five to eight times the absorption capacity of conventional mineral materials. The oil absorbed by the rubber powder is bound to the rubber so tightly that it cannot be washed out of the collecting material by water. Another advantage of a collecting material based on rubber is that whereas the rubber may be wetted on the outside it does not itself absorb water. After absorption the oil/rubber powder mass is suitable for pressing into briquettes of Refuse Derived Fuel (RDF) due to the state of the mass.

The embodiment above provides a collecting material which has a much larger capacity by weight when compared with conventional oil absorbents, that is absorbents made out of mineral materials. It provides a cost effective product for cleaning up oils/greases and certain chemicals/ quid produced in an environmentally friendly way from old tyres and other suitable surplus rubbers. Typical examples of compositions of absorbents/binders according to the invention are now set out.

1) An oil collecting material consists of rubber powder with a particle size of approximately 0.2mm - 0.71mm obtained by sieving and grading, size reduced from old whole truck tyres and predominantly consisting of natural rubber (NR) and the synthetic rubbers styrene butadiene rubber (SBR) and butyl rubber (IIR) and containing synthetic fibres.

2) An oil collecting material consists of rubber powder with a particle size in the range of 0.2mm - 0.8mm, size reduced from old passenger car tyres including styrene butadiene rubber (SBR) and butyl rubber (IIR) and synthetic fibres. Added to the rubber powder is a small percentage of clay and approximately 10% of coal dust or pulverised fuel (PF), with a particle size of approximately 1mm - 3mm.

3) An oil collecting material consists of rubber powder of similar particle size to the above examples made from a mixture of certain parts of old truck and old passenger tyres as well as rubber powder from other sources like suitable general rubber goods etc., if necessary mixed with saw dust and/or wood flour.

There are now set out examples of collecting materials according to the present invention in use.

1) lOOg of 20 mesh rubber powder with the below 60 mesh fines portion removed, was mixed with lOOg of old sump oil. The oil was bound in a matter of seconds. The sample was checked after 48 hours and the rubber mulch was virtually dry.

2) lOOg of 30 mesh rubber powder, made from non oil resistant rubbers, was mixed with 150g of old sump oil. The oil was absorbed in a few seconds. After having left the rubber powder/oil mixture for 3-4 days the oil had penetrated into the rubber powder almost completed, leaving a virtually dry rubber powder/oil mass which was easy to handle and due to the dry state, disposal did not present a problem.

3) lOOg of 40 mesh rubber powder, made from non oil resistant rubbers, was mixed with 200g of old sump oil. The oil was absorbed in a few seconds and the rubber powder/oil mixture became virtually dry in about an hour, because the oil had started to penetrate into the rubber powder rapidly due to the large surface area of the mass of rubber particles.

4) An amount of sump oil was poured onto a concrete workshop floor. A quantity of 30 mesh rubber powder, made from old tyres and consequently containing synthetic fibres, which seemed adequate to absorb this oil was strewed onto the oil immediately and most of the oil was absorbed in a few seconds. After a few minutes a further limited quantity of the same rubber powder was strewed onto the oil/rubber mass, in order to absorb the total amount of oil on the floor. Within an hour the oil/rubber mass had become so dry that it could be swept from the floor without any difficulty, and was ready to be disposed of.

5) A 50/50 mixture of 30 and 40 mesh rubber powder, made from old tyres, was strewed onto a very dirty ad greasy kitchen floor in a restaurant. The grease/oil and other dirt was readily absorbed by the rubber powder and the floor could be cleaned easily and quickly. Handling and disposal of the remaining virtually dry mass did not present a problem.

The collecting material of the present invention is also suitable for removing oil and grease etc. by shot blasting. By shot blasting with the rubber powder of this invention, oils grease etc. can be removed from products, which are manufactured by a continuous production method.

The material of the present invention can be used to rub hard grease, dried oil, tar, paint, etc. from surfaces due to the nature of the product. Conventional mineral oil absorbents cannot be used to clean surfaces by rubbing, since the rubbing action will cause the granules to change into powder. Consequently the fine rubber particles of the invention can be used as quite an aggressive absorbent/cleaner.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims:-

1. A collecting material including a rubber powder, the particles of which have dimensions in substantially all directions, lying within the range 0.1mm - 0.8mm, the rubber being non-oil resistant.

2. A material according to claim 1, characterised in that the rubber of the collecting material is natural rubber and/or non-oil resistant synthetic rubber.

3. A material according to claims 1 or 2, characterised in that rubber powder made from recycled material is used.

4. A material according to claim 3, characterised in that the recycled material is produced by a devulcanisation depolymerisation process.

5. A material according to any of the preceding claims, characterised in that new rubber is used, which may be virgin or off specification.

6. A material according to any of the preceding claims, characterised in that the rubber powder is mixed with mineral materials, for example, crushed stone or gas concrete, pulverised coal, clays, sand, calcium carbonate, barium sulphate, aluminium silicate, mineral fibres, wood flour, saw-dust, natural and synthetic fibres.

7. A material according to any of the preceding claims, characterised in that an anti-slip additive is added to the powder.

8. A material according to any of the preceding claims, characterised in that the powder is one or more of 16, 20, 30, 40 or 50 mesh size.

9. A material according to any of the preceding claims, characterised in that the collecting material may be contained by a permeable member.

10. A material according to claim 9, characterised in that the permeable member is made of fabric or plastics material.

11. A material according to claims 9 or 10, characterised in that the permeable member is in the form of a sheet, sleeve, sock or envelope.