AU5182801A - Conditioning agent - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Phillip Francis Thorpe and Beryl Ann Thorpe Phillip Francis Thorpe WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Conditioning Agent" Details of Associated Provisional Application No(s): PQ8054 filed 8 June 2000 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- Title: Conditioning Agent Field of the Invention This invention relates to a conditioning agent for use in aqueous environments to rectify acidic conditions and the use of the conditioning agent to treat acidic aqueous materials. The invention has application in the treatment of bodies of water such as rivers, lakes, ponds, reservoirs, dams, sumps, and the like as well as effluents, tailings, but is not limited to such applications.

Disclosure of the Invention Accordingly the invention resides in a method of forming a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, said method comprising washing an unset concrete composition by adding water thereto to form a slurry which is unable to set where the resultant slurry comprises the conditioning agent.

According to a preferred feature of the invention the aggregate is separated from S 15 the resultant slurry.

:..."According to a preferred feature of the invention the resultant slurry is allowed to settle, the liquid is separated from the settled solids wherein the said decanted liquid and the settled solids comprise the conditioning agent. According to a further preferred feature the aggregate is at least partially separated from the slurry before the slurry is allowed to settle.

According to a preferred feature of the invention the liquid is separated from the settled solids shortly after the slurry is initially allowed to settle. According to a preferred embodiment the separated liquid is permitted to settle to allow for at least some of the finely suspended solids to settle and the settled finely suspended solids are separated from the liquid. According to a further preferred feature the aggregate is at least partially separated from the slurry before the slurry is allowed to settle.

-3- Accordingly, in another aspect of the invention the invention resides in a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, and which comprises a slurry of watered down concrete which is unable to set. According to a preferred feature the aggregate has been at least partially removed from the slurry Accordingly, in another aspect the invention resides in a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, and which comprises settled solids which are obtained from unset concrete according to the method as described above.

Accordingly, in another aspect the invention resides in a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, and which comprises the separated liquid which is obtained from unset concrete according to the method as described above.

Accordingly, in another aspect the invention resides in a conditioning agent which 15 is intended for use in aqueous environments to rectify acidic conditions, and *:"**which comprises the settled finely suspended solids which is obtained from unset concrete according to the method as described above.

*Accordingly, in another aspect the invention resides in a method of treating an aqueous environment to reduce its acidity comprising applying a solid and/or 20 liquid conditioning agent which has been formed according to the method described above.

.According to a preferred feature of the invention the aqueous environment comprises a body of water such as a river, stream, lakes, pond, reservoir, dam sump, tailings dump and the like.

According to a preferred feature of the invention the aqueous environment comprises an aqueous effluent.

According to a preferred feature of the invention the aqueous environment comprises aqueous tailings.

-4- The invention will be more fully understood in the light of the following description of several specific embodiments.

Description of Specific Embodiments The embodiments relate to the formation of a conditioning agent from an unset concrete composition.

It has been found that in concrete batching plants, in which concrete is formed to be delivered to a site by vehicles, it is not an uncommon circumstance for those delivery vehicles to return to the batching plant with some residual concrete remaining in the vehicle. In the past, it has been usual practice to merely wash the residual concrete from the vehicle and deposit the resultant slurry into a waste sump, allow the water to drain and/or evaporate from the slurry and then break up the resultant solid material resident in the sump in order that the resultant solid material can be used as road base. According to alternative practices the waste concrete is washed from the vehicle, the aggregate and sand is separated from 15 the slurry for use in making fresh concrete or as road base and the resultant liquid is used for the production of fresh concrete.

According to the first embodiment, the residual concrete in the vehicles is washed from the vehicle and delivered into a roller screen whereby most of the aggregate material is separated from the slurry passing from the vehicle. The separated aggregate is collected for reuse either in fresh concrete or elsewhere. The **resultant screened slurry is then allowed to pass from the screen and is collected in a sump where the solids in the slurry are allowed to settle. After a period of time which is sufficient to allow for the adequate settlement of the solids, the water is decanted or drained from the sump to leave the settled solids resident in the sump. The settled solids are then extracted from the sump and are further dewatered. This dewatering may comprise forming the settled solids into a heap and allowing for the natural drainage of the water from the heaped material.

It has been found that the resultant material can serve as a conditioning agent for aqueous environments to adjust the pH of acidic aqueous environments because of the high inherent pH of the conditioning agent.

According to one example of the invention, the method of the embodiment was applied to waste concrete which had been manufactured at a batching plant in Capel, Western Australia and which was formed from an aggregate formed from a basalt rock which was derived from the Gelorup quarry. In addition the concrete contained sand which had been obtained locally. The application of the method was found to produce a conditioning agent having a pH of 12 and having the following constituents: Phosphate 55 mg/Kg Potassium 266 mg/Kg Calcium 7080 mg/Kg Magnesium 250 mg/Kg Zinc 0.1 mg/Kg Copper 0.2 mg/Kg Iron 110 mg/Kg Manganese 3.6 mg/Kg It is believed that use of the conditioning agent derived from the example referred to above, with acidic aqueous environments can result in the pH of the environment being neutralised significantly. The conditioning agent can be used to control the ph of effluent and tailings streams, ponds used in fish farming, tailings dumps, abandoned mine workings, the drainage streams from acidic mine workings, farm dams that have become acidified due to inherent ground conditions and/or the leaching of fertiliser from the surrounding soil and to otherwise ameliorate acidic conditions of aqueous environments According to a second embodiment of the invention the liquid suspension which in the case of the first embodiment is decanted or drained from the sump subsequent to settling can be used as a conditioning agent in the light of it's alkalinity.

According to a third embodiment of the invention the separated liquid of the second embodiment comprises a liquid suspension of fine particulate material. In the case of the third embodiment the liquid suspension is allowed to settle to permit a substantial portion of the fine particulate material to settle. The liquid is then separated from the settled fine particulate material and both the liquid and the settled fine particulate material is used separately as a conditioning agent.

According to an example of the third embodiment the decanted or drained liquid which was separated in the example of the first embodiment described above produced a separated liquid suspension which if allowed to fully settle resulted in a liquid portion and a sediment portion which both had a pH of 12. The liquid portion had the following constituents;

C

C.

C

Total Phosphorous 41 microg/litre Potassium 35.1 mg/tr Calcium 206.8 mg/ltr Magnesium 0.2 mg/ltr Zinc 0.2 mg/ltr Copper <0.1 mg/ltr Iron 1.6 mg/ltr Manganese <0.1 mg/ltr while the sediment portion had the following constituents: Phosphate 251 mg/Kg Potassium 748 mg/Kg Calcium 54337 mg/Kg Magnesium 4396 mg/Kg Zinc 46.5 mg/Kg Copper 31.1 mg/Kg Iron 9166 mg/Kg Manganese 127.8 mg/Kg Therefore the decanted liquid suspension provides a valuable means for conditioning aqueous environments in that it can be used to improve the pH of acidic aqueous environments. In addition the sediment can similarly be used as a conditioning agent to improve the pH of acidic aqueous environments.

According to a fourth, fifth and sixth embodiment of the invention, the aggregate is not separated from the slurry prior to settling in case of the first second and third embodiments respectively.

According to a seventh embodiment of the invention the waste concrete is washed from the vehicle and if desired the resultant slurry is further diluted to produce a concrete slurry which is unable to set to form a solid and the resultant the slurry is used as a conditioning agent. In use of the concrete slurry as a conditioning agent it may be necessary to provide a means of agitating the slurry to keep the solid constituents in suspension, at least during the application phase.

According to a eighth embodiment which is a variation of the seventh embodiment the aggregate is separated from the concrete slurry before the slurry is used as a conditioning agent. In use of the concrete slurry as a conditioning agent it may be necessary to provide a means of agitating the slurry to keep the solid constituents in suspension, at least during the application phase.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or, group of integers.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiment described above.

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Claims (16)

1. A method of forming a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, said method comprising washing an unset concrete composition by adding water thereto to form a slurry which is unable to set where the resultant slurry comprises the conditioning agent.

2. A method of forming a conditioning agent as claimed at claim 1 wherein the aggregate is at least partially separated from the resultant slurry.

3. A method of forming a conditioning agent as claimed at claim 1 or claim 2 wherein the resultant slurry is allowed to settle to settle, the liquid is separated from the settled solids wherein the said decanted liquid and the settled solids comprise the conditioning agent. ooo 4. A method of forming a conditioning agent as claimed at claim 3 as S 15 dependant from claim 2 wherein the aggregate is at least partially separated from the slurry before the slurry is allowed to settle. A method of forming a conditioning agent as claimed at any one of the preceding claims wherein the liquid is separated from the settled solids shortly after the slurry is initially allowed to settle.

6. A method of forming a conditioning agent as claimed at claim 5 wherein the separated liquid is permitted to settle to allow for at least some of the finely suspended solids to settle and the settled finely suspended solids are separated from the liquid.

7. A method of forming a conditioning agent which is intended for use in aqueous environments to rectify acidic conditions substantially as herein described.

8. A conditioning agent which is intended for use in aqueous environments to rectify acidic conditions, and which comprises a slurry of watered down concrete which is unable to set.

9. A conditioning agent as claimed at claim 8 wherein the aggregate has been removed from the slurry A conditioning agent which is intended for use in aqueous environments to rectify acidic conditions and which comprises the settled solids which are obtained from unset concrete according to the method as claimed at any one of claims 1 to 7.

11. A conditioning agent which is intended for use in aqueous environments to rectify acidic conditions and which comprises the separated liquid which is obtained from unset concrete according to the method as claimed at any one of claims 1 to 7.

12. A conditioning agent which is intended for use in aqueous environments 15 to rectify acidic conditions and which comprises the settled finely suspended solids which is obtained from unset concrete according to the method as claimed at any one of claims 1 to 7.

13. A conditioning agent which is intended for use in aqueous environments to rectify acidic conditions substantially as herein described.

14. A method of treating an aqueous environment to reduce it's acidity ::comprising applying a solid and/or liquid conditioning agent which has been formed according to the method as claimed at any one of claims 1 to 7. A method of treating an aqueous environment to reduce it's acidity comprising applying a solid and/or liquid conditioning agent of the form as claimed at any one of claims 8 to 13. -11-

16. A method of treating an aqueous environment to reduce it's acidity as claimed at claim 14 or 15 wherein the aqueous environment comprises a body of water such as a river, stream, lakes, pond, reservoir, dam sump, tailings dump and the like.

17. A method of treating an aqueous environment to reduce it's acidity as claimed at claim 14 or 15 wherein the aqueous environment comprises an aqueous effluent.

18. A method of treating an aqueous environment to reduce it's acidity as claimed at claim 14 or 15 wherein the aqueous environment comprises aqueous tailings.

19. A method of treating an aqueous environment to reduce it's acidity substantially as herein described 99'9 Dated this Eighth day of June 2000. Phillip Francis Thorpe Beryl Ann Thorpe ~Applicants Wray Associates Perth, Western Australia S: "Patent Attorneys for the Applicant(s) 9 o.

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