|Title of Invention||
A PROCESS OF MANUFACTURE OF ABRASIVE GRAINS AT AMBIENT TEMPERATURE FOR PROVIDING A UNIFORM, HARD, SURFACE THEREON
|Abstract||ABSTRACT A PROCESS OF MANUFACTURE OF ABRASIVE GRAINS AT AMBIENT TEMPERATURE FOR PROVIDING A UNIFORM HARD SURFACE THEREON A process of manufacture of abrasive grains at ambient temperature for providing a uniform hard surface thereon, comprising the steps of wetting the said grains with phosphoric acid (upto 5% by weight of the of the grains); preparing a blend of any oxide of copper and aluminous compound in the ratio 30:70 to 70;30; adding tide blend to the wetted grains in the ratio of 2:1 to 6:1 to the weight of the acid and mixing the same, before allowing to cool at ambient temperature.|
This invention relateis to a process o-f manufacture of abrasive grains at ambient temperature for providing a uniform hard, surface thereon leading to delayed fracture and therefore, enhanced life of abrasive wheels made from such grains.
We have proposed a process whereby abrasive grains are chemically modified to provide a uniform^ hard, surface thereon - This is covered by our Patent Application No. /HAS/97.
However in that process the treated abrasive grains wi11 have to be fired in a furnace from 300 deg C to 700 deg.C. On the other hand, in the process proposed herein the bonding takes place at room temperature itself thereby avoiding furnacing and saving substantial energy.
In this process abrasive grains are wetted with any type of phosphoric acid (up to 5X by weight of the grains) in a suitab 1 e mixer- A b 1 end of any oxide of copper and aluminous compound in the
prooortion 30:70 to 70:30 is prepared. This blend in the ratio of 2:1 to 6:1 to the weiqht of the acid is added to the wetted qraing and mixed The qrains are then collected in travs and allowed to cool at ambient temperature These are now ready for use, Grinding aids such as substances se1ected from iron oxide and chromium oxide may be included in the blend,
Electrical property alterinq additives may also be
included in the blend- These additives are selected
from electrical1V conductive material, such as, SiC, Iron Oxide, and metal powjders-
The process of manVAf ac t,ure of abT"asi ve qraiT"ts at ambi ent temperature providing a unifarm, hard surface thereon., accord inq to this invention, comprises the steps of uiettinq the said qrains with phasphoric acid (up to 5% by weight of the grains preparing a blend of any oxide of copper and an aluminous compound in the ratio 30:70 to 70s30? addinq the blend to the wetted qrains in the ratio of 2 1 to 6:1 to the weiqht of the
acid and mixing the same, befors allowing to cool at
The qrains are now ready for use.
Grindinq aids such as powdered fines selected from iron oxide and chromium oxide and electrical property alterinq additives selected from fine particles of BiC, iron oxide, metal powders and other electrically conductive materials; alumina, refractory oxides, rare earth materials, electrically insulatinq material may also be included in the blend.
EXAMPLE I Abrasive aluminium oxide was wetted with phosphoric acid (5% by weight of the qrains)-
A blend made up of 40:60 ratio of oxide of copper and calcined alumina was added in proportion of 4:1 of the weight of the acid and further mixed. Heat is evolved durinq mlxinq-
The qrains were then transferred to trays and allowed to cool in ambient temperature The qrains were tested
The terms and expressions in this specification are of description and not of 1 imitation, there being no intention in the use of such terms and expressions of excluding any equivalents of the features illustrated and described, but it is understood that various other modes of carrying out the process proposed herein are possible without departing from the scope and ambit of this invention.
1. A process of manufacrture of abrasive grains at ambient temperature for praviding a uniform, hard surface thereon, comprising the steps of wetting the said grains with phosphoric acid characterised in that the phosphoric acid is up to 5% by weight of the grains: preparing a b 1 end of any oxide of copper and an a1uminous compound in the ratio 30 : 70 to 70: 30 : adding the blend to the wetted grains in the ratio of 231 to 6:1 to the weight of the acid and mixing the same, before allowing to cool at ambient temperature-
2. A process as c1aimed in Claim wherein i n the b1end inc1udes grinding aids se1ected from oxides such as iran oxide and chromium oxide
3. A process as claimed in any one of the preceding Claims wherein the blend includes electrical property altering additives selected from fine particles of SiC, iron oxide, metal powderS and other electrically conductive materials alumina, refractory oxides, rare earth materi als, electrically insulating material.
4.A process of manufacture of abrasive grains at ambient temperature for providing a uniform, hard surfac e the reon substantia11y as herein described and illustrated by the Example-
|Indian Patent Application Number||2173/MAS/1997|
|PG Journal Number||30/2009|
|Date of Filing||01-Oct-1997|
|Name of Patentee||CARBORUNDUM UNIVERSAL LIMITED|
|Applicant Address||TIRUVOTTIYUR, CHENNAI - 600 019|
|PCT International Classification Number||B24D3/16|
|PCT International Application Number||N/A|
|PCT International Filing date|