CA2706781C - Abrasive materials from biological sources - Google Patents

Abstract

Thermally and mechanically treated bones, from non-living animals, and/or eggs, from living animals, transformed into a powdery form, can be used as abrasive materials for jet blasting or to fabricate abrasive papers. This invention describes the use of powders made from incinerated dead animals, said animals coming from land or sea, and/or made from eggs from living animals, said animals coming from land or sea as well. All organic content is eliminated from raw materials through thermal processes. Inorganic end products are crushed and grinded into a powdery form. Powders obtained thereafter, both thermally and mechanically processed, are used as abrasive materials, said materials used as is or mixed with other compounds. These latters can be glued on paper substrates to make abrasive papers, or on abrading wheels, bands or disks, regardless of the underneath material. Abrasive powders can also be used in electrocomposite formulations.

Description

Abrasive materials from biological sources BACKGROUND OF THE INVENUON
1. Field of the Invention Metallic substrates, such as steel or aluminum parts commonly encountered into the fabrication of many domestic and industrial equipments, machines and even vehicles, are subjected to both atmospheric and/or aquatic corrosion. Therefore, several surface treatments have been developed through time to counteract the detrimental effects of corrosion upon metal parts. Among thcsc surface treatments, there is plating, anodizing, painting and so forth. Prior to surface treatment, surface preparation is often needed. One of most applied surface preparation for metal parts consists of sandblasting with abrasive material. A jet-propelled abrasive powder is blasted over the metallic surface at such a pressure that the powder particles mechanically abrade the surface, hence removing all traces of oxide and dirt. The cleaned part is then ready to be subsequently treated with a layer or layers of protective coatings such as zinc or paint as examples.
The use of abrasive materials for surface preparation is well known. Powders made from abrasive particles can be made of cerarnic or plastic media, depending upon the targeted application and substrate properties. Since combinations of abrasive-substrate are infinite, and because new materials are constantly fabricated, the needs for innovative and performant abrasive materials are increasingly seeked.
In another domain, millions of tons of carcasses of dead animals, both from land and sea, are disposed on landfields every year. These carcasses are most of the time wasted, unfortunately. However, they represent huge masses of biological matter from which a solid material can be extracted. Bones and shells, including egg shells of laying animals, represent important biological sources of ceramic-like material that can be converted into powders or flakes finally used as abrasive materials. So, if on one end there are needs for new abrasive materials and if on an other end there is a possibility to recycle biological materials such as bones and egg shells for instance, then, by combining both situations a new invention is coming up.
The present invention relates to the fabrication and applications of new abrasive materials, as powders or flakes, obtained through thermal and mechanical processes such

2 as incineration or heating followed by crushing and grinding of raw materials from various biological sources. The said raw materials can be non-living animal bones, animal eggs or sea animal shells. These materials usually, but not exclusively, contain organic matter that has to be eliminated from their solid structure prior to be further used as abrasive materials. This invention covers the use of the final powders as abrasive materials once the organic matter has been eliminated through incineration or other thermal treatments. Thus, powders are produced from the inorganic portion of the initial animal matter. Depending upon the temperature and time at which the raw material is being exposed, most of, or the entire content of water content is gone simultaneously with the organic matter. This is where the chemical composition and physical structure of raw material is initially altered. The raw material that is too big is size to be used as a powder for jet blasting or abrasive paper fabrication is crushed and grinded until the end product reaches an average particle size that is suitable for standard blasting equipment, or suitable to be used for abrasive papers, abrasive bands and whells fabrication.
The present invention relates to the transformation of non-living animal bones, eggs or shells into powders, said powders being used as abrasive materials. The abrasive properties of powders come from the chemical composition and physical intrinsic structures of these tatters. the chemical compositions of the animal-source materials are altered by the thermal processes they are going through while their physical structures are altered by the crushing and/or grinding processes that follow, although nothing opposes to the reverse application of the thermal and crushing/grinding processes.
The present invention represents a recycling application of commonly disposed biological matter. Incinerated animal-source materials can be used as abrasive powders since its solid proportion can be chemically considered as ceramics. These latters being usually hard enough to create an abrasive effect upon other solid material when blasted or sanded with them. Several applications of the powders obtained form this invention, given as examples, but not limited too, as abrasive media can be mentionned : desealing of welded stainless steel alloys, rust removal of steel alloys, paint removal on aluminum aircraft skins, pre-treatment of concrete blocks, sanding of wood planks prior to varnishing and jet blasting for numerous other surface treatments. =
2. Description of Prior Art Several U.S patents are directly related to inorganic powder particles used as abrasive materials for various applications. Among these materials, ceramic and/or ceramic-like powders having a hardness that lies between 4 and 8 on the moh scale are use for what is commonly called sandblasting, or jet blasting. Considered as surface preparations methods, these latters are well known since decades and a wide variety of powdery materials for blasting or sanding from papers already exist for may applications. Abrasive materials are used to remove scale, rust and other types of metallic oxidation layers over metal parts, such as landing gears prior to plating. Other applications of jet blasting are paint removal, on aircraft aluminum skins par example, or surface roughing, on solid substrates prior to I-IVOF treatments. For oxidation removal, hard particles jet propelled

3 at high velocity over 80 psi arc usually taken, while paint or varnish removal on soft substrates are performed with softer particles. For many years, the most widely used No.
corundum structure, silicon oxide and plastic media.
Abrasives material from biological sources can be used for numerous applications including those previously described.
U.S. Patent No. 4,115,076 discloses a non-toxic abrasive material made from an iron metallic oxide, a type of ceramic-like compound, for cleaning ferrous metals by blasting, prior to painting. This type of oxide is chemically simple in terms of composition.
Vontell et al disclose in their U.S. Patent No. 4,680,199 a method for depositing a layer of abrasive material on a substrute. Although the method described in performed in a vacuum chamber is quite complex, it reveals another application of abrasive particles, namely their deposition over a substrate to make a layer of these particles for a specific application. However, depositing abrasive particles over a substrate such as paper, by sticking them with an appropriate binder, may produce sandpapers. Such material can be produced with abrasive materials from biological sources.
Aluminum oxide or similar corundum-like compounds, as previously described, is one of the most used abrasive materials, particularly used for oxide or rust removal.
Such material is disclosed in U.S. Patent No. 4,799,938. Among the applications described into this patent are the fabrication of grinding bands or discs. A similar compound used as an abrasive material is also claimed in U.S. Patent no. 4,906,255.
Other very hard materials, in powdery forms, are also used as abrasives. U.S.
Patents discloses the use of cemented carbide containing cubic boron nitride, as an abrasive and wear resistant material. This type of combined compounds drives the development of other powders made from the combinaison of various powdery materials used for other applications. In U.S. Patent no. 5,259,147 Falz et al disclose the fabrication of a granular abrasive material produced from a dispersion of raw materials containing alumina, coumpounds containing silica and other additives. A similar approach can be exploited with abrasives from biological sources.
The use of soft abrasive material, such as calcium carbonate powder, is disclosed in U.S.
Patent No. 5,531,634. However, Schott claims a material that is between 4.00 to 4.50011 the moh's scale when its weight composition is at least 96 %. Egg shells have an average hardess of 3.00 and a maximum content of 94% in calcium carbonate.
Nervertheless. egg shells as a blasting material to remove organic coatings is very efficient.
That what makes a difference between this latter patent and the present claimed invention.
A method and apparatus for separating a protein membrane and shell material in waste egg shells is disclosed in U.S. Patent No. 6,176,376. No mention is given concerning the use of egg shells as abrasive material, aside from its disposal.
Finally. U.S. Patent No. 6,824,578 from Uchino et al, discloses a polishing material made from abrasive materials mixed with other chemical compounds to increase its efficiency

4 as so. It is possible to mixed abrasive material from biological sources with other chemicals as well in order to achieve other abrasive or polishing effects.
In conclusion, nothing was found in the prior art, disclosing the application of powder materials from biological sources, as abrasives, materials being bones, egg shells, shellfishes shells, oysters. lobsters and other similar sea animals.
Therefore, this invention has never been claimed prior to this one.
SUMMARY OF THE INVENTION
The present invention relates to the use of powders produced from biological sources such as non-living animals, coming from land or sea, once transformed through various thermal, crushing and grinding processes. These non-living animals comprise, for example, bones from incinerated dead animals, egg shells, oyster shells, mussels and other species of shellfishes, corals and fishbones. Dead animals, once thermally treated to extract organic matter from inorganic matter, are transformed into clusters, flakes or chunks then crushed and grinded into powders. These tatters shall be exempted of bacteria, such as salmonella, E-coli, and shall not contain heaver metals or other toxic compounds beyond limits that are not considered acceptable depending upon the targeted application, country rules and regulation and/or analysed and evaluated such that is can be proven not being harmful to environment or toxic toward human exposure, prior to their use as abrasive materials.
Powders can be chemically considered as ceramic particles, having altered structure caused by thermo-mechanical transformation during their treatment. The chemistry of the altered structure of the powders is also altered simultaneously, for instance, an increase in bonded oxygen and/or a decrease in water or carbone dioxide content. Both physical and chemical properties are different from the raw materials they come from, prior to transformation. Once heated, crushed and/or grinded at various sizes, preferably between 0,1 mm and 4,0 mm, powders, as is or mixed with other powder types and/or other compounds, may be used as abrasive material, as jet blasting media or as sandpaper media. They may also be used in composite abrasive material, as mixed with other materials such as ceramics, metals or polymers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is now explained in more details with descriptions of preferred applications and examples.
Abrasive particles draw their applications as such from their intrinsic physical properties.
These tatters include hardness, resilience, density, structural geometry and other factors.
For example, bones from animals having an average hardness of 5 on the moh scale but are less resilient than aluminum oxide, or corundum. The chemical composition of bones is basically a mixture of calcium phosphate, calcium carbonate, calcium fluoride and magnesium phosphate. Once exposed to heat above 250 degrees celcius, a bone loses its water content, and its initial cristalline structure is therefore altered.
This latter is even more altered after crushing and grinding. however, its average harness is high enough to bc used as an abrasive media, thus, representing a part of this claimed invention, namely the use of such material for application as an abrasive material.
Eggs. from hens, quails, turkeys and other laying animals, are described, in this invention, under the same considerations than animal bones. The chemical composition of eggs is moreless similar to bones, namely, a mixture of calcium carbonate, magnesium carbonate and calcium phosphate. However, the hardness of egg shells is lower than bones, about 3 on the moh scale. Hence, its properties as abrasive material are different since it is softer and less resilient than bone powder. It makes it more appropriate to be used to remove organic coatings such as paint or varnish on softer substrates.
Shells from shellfishes, such as lobsters, crabs, shrimps, mussels, oysters and other similar animals are chemically closer to eggs than bones. The main compound encountered in these types of shells is calcium carbonate. Shells from shellfishes are more resilient than eggs.
Once freed from their organic matter content by an appropriate thermal treatment, bones, eggs or shells can be considered as inorganic compounds, similar to ceramics.
However, thermal treatments, depending upon the process being used, alter the structure of the initial solid raw material. Furthermore, subsequent mechanical treatments such as crushing and grinding, alter even more the structure of the solid matter. In consequence, processed powders obtained from biological sources are different in structure, composition and properties than original solid raw material. Nevertheless, the obtained powders can be used as abrasive materials although they are not exactly of the same composition and structure than the original matter.
The use of all powders issued from non-living animals remains such as bones, or eggs and shells, thermally and mechanically treated, as abrasive materials represents an innovative application of such matter, justifying this disclosed invention.
EXAMPLE NO.1 Domestic or farm animals are incinerated for 4 hours at 250 degrees celcius into a furnace, to eliminate organic matter and water molecules, thereafter, only bones from these animals remain. The bones are subsequently collected from furnace once temperature allows their manipulation and they are crushed and grinded until an average 2,0 mm particle size is obtained. Particles of powder are then put into a sandblasting equipment settled to propel particles at a pressure of 60 psi. Target being a rusted steel parts, the particles are jet blasted at a distance of 12 inches with an angle of 90 degrees between the target and the nozzle of the blasting machine. Jot blasting is maintained until all the rust at the surface of the target is gone.
EXAMPLE NO.2 Hens egg shells are heated at 150 degrees ecicius for 2 hours, after an extraction from the liquidous substance they bear. The heat destroys all remaining organic matter that covers the shell flakes, including bacterial load, and dehydrates the egg shell structure. Egg shell flakes are subsequently collected from furnace once temperature allows manipulation and then crushed until an average 1,5 mm particle size is obtained. Particles are then put into a sandblasting equipment settled to propel particles at a pressure of 80 psi.
Target being a painted aluminum part, the particles are jet blasted at a distance of 9 inches with an angle of 70 degrees between the target and the nozzle of the blasting machine. Jet blasting is maintained until all the paint at the surface of the target is gone.
EXAMPLE NO.3 An abrasive powder made from animal bones, said powder being crushed and grinded to an average particle size of 2,0 ram is projected on steel parts to remove heat scale prior to machining, at a jet pressure of 90 psi, with a jet-target distance of 5 inches at a 60-degree angle until scale is completely removed.
EXAMPLE NO.4 An abrasive powder made from egg shells, said powder being crushed to an average particle size of 1,0 mm is projected on aluminum sheets of aircraft to remove old paint prior to chemical conversion coating followed by painting, at a jet pressure of 50 psi, with a jet-target distance of 4 inches at a 45-degree angle until old paint is totally removed.
EXAMPLE NO.5 An abrasive powder made from shellfishes, crab shells and mussels, said powder being crushed and grinded to an average particle size of 1,5 mm is projected on concrete blocks to remove staining prior to sealing followed by painting, at a jet pressure of 40 psi, with a jet-target distance of 5 inches at a 80-degree angle until stains and dirt are totally removed.
EXAMPLE NO.6 An abrasive powder made from egg shells, said powder being crushed to an average particle size of 1,0 mm is glued on a 144 square inches sheet of paper, hence creating a standard sand paper, to remove roughness and small defects on wood planks, such as oak or pine, prior to varnishing.
EXAMPLE NO.7 An abrasive powder made from a mixture of bones and shellfishes, said powder being crushed to an average particle size of 0,8 mm is glued on a 144 square inches sheet of paper, hence creating a standard sand paper, to remove oxidation and small defects on steel parts, prior to surface finishing, such as plating or HVOF.

Claims (63)

WHAT IS CLAIMED IS:

1. A jet blasting powder, the jet blasting powder including animal derived particles in powder form, wherein the animal derived particles have a hardness of between 1 and 9 on the Moh scale.

2. The jet blasting powder as defined in claim 1, wherein the animal derived particles are bone derived.

3. The jet blasting powder as defined in claim 1, wherein the animal derived particles are eggshell derived.

4. The jet blasting powder as defined in claim 1, wherein the animal derived particles are shellfish derived.

5. The jet blasting powder as defined in claim 1, wherein the animal derived particles are crustacean shell derived.

6. The jet blasting powder as defined in claim 1, wherein the animal derived particles are coral derived.

7. The jet blasting powder as defined in claim 1, wherein the animal derived particles are fish bone derived.

8. The jet blasting powder as defined in claim 1, wherein the jet blasting powder consists essentially of animal derived particles.

9. The jet blasting powder as defined in any one of claims 1 to 8, wherein the animal derived particles are inorganic.

10. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have a grain size between 0.1 mm and 4 mm.

11. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have a grain size between 0.01 mm and 10 mm.

12. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have 1 mm in average size.

13. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have 0.8 mm in average size.

14. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have 1.5 mm in average size.

15. The jet blasting powder as defined in any one of claims 1 to 9, wherein the animal derived particles have 2 mm in average size.

16. The jet blasting powder as defined in any one of claims 1 to 15, wherein the jet blasting powder also includes auxiliary particles selected from the group consisting of ceramic particles, metal particles and polymeric particles.

17. The jet blasting powder as defined in any one of claims 1 to 16, wherein the animal derived particles have a hardness of 5 on the Moh scale.

18. The jet blasting powder as defined in any one of claims 1 to 16, wherein the animal derived particles have a hardness of 3 on the Moh scale.

19. The jet blasting powder as defined in any one of claims 1 to 18, wherein the jet blasting powder is free of organic materials.

20. The jet blasting powder as defined in any one of claims 1 to 19, wherein the animal derived particles each include at least one of calcium phosphate, calcium carbonate, calcium fluoride, magnesium phosphate and magnesium carbonate.

21. A method for treating a surface, the method comprising jet blasting the surface with the jet blasting powder as defined in any one of claims 1 to 20.

22. The method as defined in claim 21, wherein the surface is a surface of a wood plank, jet blasting the surface including sanding the wood plank.

23. The method as defined in claim 21, wherein the surface is a surface of a concrete block, jet blasting the surface including sanding the concrete block.

24. The method as defined in claim 21, wherein the surface is a painted metallic surface, jet blasting the surface including removing paint from the painted metallic surface.

25. The method as defined in claim 21, wherein the surface is a surface of a metal alloy, jet blasting the surface including descaling the metal alloy.

26. The method as defined in claim 21, wherein the jet blasting powder is jet blasted at 60 PSI.

27. The method as defined in claim 26, wherein the jet blasting powder is jet blasted at 90 degrees relative to the surface.

28. The method as defined in any one of claims 26 to 27, wherein the jet blasting powder is jet blasted at 12 inches from the surface.

29. The method as defined in any one of claims 26 to 28, wherein the jet blasting powder is bone derived.

30. The method as defined in claim 21, wherein the jet blasting powder is jet blasted at 80 PSI.

31. The method as defined in claim 30, wherein the jet blasting powder is jet blasted at 70 degrees relative to the surface.

32. The method as defined in any one of claims 30 to 31, wherein the jet blasting powder is jet blasted at 9 inches from the surface.

33. The method as defined in any one of claims 30 to 32, wherein the jet blasting powder is egg shell derived.

34. The method as defined in claim 21, wherein the jet blasting powder is jet blasted at 50 PSI.

35. The method as defined in claim 34, wherein the jet blasting powder is jet blasted at 45 degrees relative to the surface.

36. The method as defined in any one of claims 34 to 35, wherein the jet blasting powder is jet blasted at 4 inches from the surface.

37. The method as defined in any one of claims 34 to 36, wherein the jet blasting powder is egg shell derived.

38. The method as defined in claim 21, wherein the jet blasting powder is jet blasted at 40 PSI.

39. The method as defined in claim 38, wherein the jet blasting powder is jet blasted at 80 degrees relative to the surface.

40. The method as defined in any one of claims 38 to 39, wherein the jet blasting powder is jet blasted at 5 inches from the surface.

41. The method as defined in any one of claims 38 to 40, wherein the jet blasting powder is derived from shells of shellfish.

42. The method as defined in claim 21, wherein the jet blasting powder is jet blasted at 80 PSI.

43. The method as defined in claim 42, wherein the jet blasting powder is jet blasted at 60 degrees relative to the surface.

44. The method as defined in any one of claims 42 to 43, wherein the jet blasting powder is jet blasted at 5 inches from the surface.

45. The method as defined in any one of claims 42 to 44, wherein the jet blasting powder is bone derived.

46. A method for manufacturing the jet blasting powder as defined in any one of claims 1 to 20, the method comprising:
- treating with heat through heating or incinerating animal derived materials in conditions resulting in elimination of organic portions of the animal derived materials to produce an intermediary product;
- breaking into particles the intermediary product to obtain the jet blasting powder.

47. The method as defined in claim 46, wherein breaking into particles includes crushing.

48. The method as defined in any one of claims 46 to 47, wherein breaking into particles includes grinding.

49. The method as defined in any one of claims 46 to 48, wherein treating with heat is performed at above 250 degrees Celsius.

50. The method as defined in claim 46, wherein - the animal derived materials include at least part of an animal carcass;
- treating with heat through heating or incinerating the animal derived materials includes incinerating the at least part of the animal carcass;
- the intermediary product includes heat treated bones products;
- breaking into particles the intermediary product includes crushing the heat treated bones products.

51. The method as defined in claim 50, wherein incinerating includes incinerating at 250 degrees Celsius.

52. The method as defined in any one of claims 50 to 51, wherein incinerating includes incinerating for 4 hours.

53. The method as defined in any one of claims 50 to 52, wherein crushing includes crushing to achieve an average particle size of 2mm.

54. The method as defined in claim 46, wherein - the animal derived materials includes egg shell products;
- treating with heat through heating or incinerating the animal derived materials includes heating the egg shell products;
- the intermediary product includes heat treated egg shell remains;
- breaking into particles the intermediary product includes crushing the heat treated egg shell remains.

55. The method as defined in claim 54, wherein heating includes heating at 150 degrees Celsius.

56. The method as defined in any one of claims 54 to 55, wherein heating includes heating for 4 hours.

57. The method as defined in any one of claims 54 to 56, wherein crushing includes crushing to achieve an average particle size of 1.5 mm.

58. The method as defined in any one of claims 54 to 56, wherein crushing includes crushing to achieve an average particle size of 1 mm.

59. An abrasive product including the powder of any one of claims 1 to 20 glued to a sheet of paper.

60. The abrasive product as defined in claim 59, wherein the animal derived particles have an average particle size of 1 mm.

61. The abrasive product as defined in any one of claims 59 to 60, wherein the animal derived particles are eggshell derived.

62. The abrasive product as defined in claim 59, wherein the animal derived particles have an average particle size of 0.8 mm.

63. The abrasive product as defined in any one of claims 59 or 62, wherein the animal derived particles include both shellfish and bone derived particles.