Title of Invention

"A COMPOSITION USEFUL FOR QUARY BLASTING AND EXCAVATION WORKS"

Abstract

A Composition Useful for Quarry Blasting and Exacavation Work. A composition has been developed without conventional metal powder or explosive ingredients, useful for quarry blasting. It is a cap sensitive explosive composition comprising an oxidizing agent, a reducing agent, a cross linking agent and a gassing agent. The composition is also useful for construction of road or earth exacavation projects but not suitable for defence purpose.

Full Text

This invention relates to a composition useful for excavation work. It particularly relates to a composition developed without metal powder and molecular/explosive ingredients. It is cap sensitive explosive composition for rock excavation, shaft shrinking, water channel, construction of road and suitable to other earth excavation projects, and not for defence / Military purposes. At present four type of commercial compositions are available in India. These are Nitroglycerine (NG) based, ammonium nitrate/fuel oil mixture, slurry and emulsion explosives. The NG based explosives are available in cartridge form in various diameter from 25 to 200 mm and weight from 130 gm to 12.5 kg. These explosives have high velocity of detonation (VOD) ranging from 2000 to 6000 m/sec. Their density varies from 0.8 to 1.35 gm/cm3. They are high sensitive to shock, friction, heat and flame. Their fume quality is poor. The NG based explosives are high density and high shattering power poses many safety problems. To decrease loading density of explosives sometime spacers ( wood or plastic) are used due to which sometime misfiring occurred. When misfired explosives mixed in blasted muck which may cause accident during loading and also it is highly sensitive to impact and friction their by increased the danger during the operation. Ammonium nitrate and fuel oil mixture ( AN/FO) is non-cap sensitive and low velocity of detonation which varies from 2400 to 4500 m/sec. Its density is about 0.8-0.9 gm/cm3. Slurry explosives are available in cartridge form having a diameter from 25 to 200 mm and weight 140 gm to 12.5 kg. They are both cap and non-cap sensitive composition. Their VOD varies from 3 3000 to 4500 m/sec and density vareis from 1.1 to 1.15 gm/cm . Emulsion explosives have high VOD ranging from 3500 to 6000 m/sec. They are both cap and non-cap sensitive. They are avail¬able in cartridge form wherein diameter ranges from 25 to 200 mm. At present nitroglycerine CNG) based as well as slurry and emulsion explosives are available to use in rock excavation projects. Their velocity of detonation and detonation pressure are very high resulting in high shattering effect. Slurry compo¬sition is sensitised by using atomised or flake grade aluminium powder or monomethylamine nitrate molecular explosives with increasing demand of aluminium powder and monomethylamine ni¬trate, there is need to use other sensitizer to make cap-sensi¬tive explosives with low order of detonation below 3000 m/sec. The main objective of present invention is to provide a composition for excavation work without using any organic nitrate or metal powder. The composition is useful for quarry, tunnel blasting and other excavation works. The present invention utilizes ingredients of oxidising agent, reducing agent, cross-linking agent and gassing agent to form zero oxygen balance to produce suitable composition for excavation projects such as construction of road, quarry blasting and other excavation work. The oxidising agent such as ammonium nitrate, sodium nitrate and potassium nitrate is mixed with coal powder/activated carbon, gum alongwith cross-linking and gassing agents to produce the zero oxygen balance composition in the powder form. Accordingly, the present invention provides a composition useful for quarry blasting and other excavation works which comprises an oxidizing agent selected from ammonium nitrate, sodium nitrate, calcium nitrate and potassium nitrate in the range of 85 to 95 wt %, reducing agent selected from coal powder/activated carbon and guar gum in the range of 5 to 10 wt%, a cross linking agent selected from potassium dichromate, potassium antimony tartrate in the range of 0.3 to 0.5 wt%, and a gassing agent such as sodium nitrite from in the range of 0.3 to 0.4 wt% . The oxidizing agent used may be selected from ammonium nitrate, potassium nitrate, sodium nitrate, calcium nitrate are of 99% of purity and particle size The reducing agent used may be selected from coal powder/activated carbon and guar gum of 90% purity and particle size The cross-linking agent used may be selected from potassium dichromate/ or potassium antimony tartrate of 95% purity and particle size After weighing the required quantities, these are intimately mixed together either by hand or by employing a mechanical mixer. The composition thus prepared is sensitive enough to be initiated for detonation with the help of detonator no. 6 consisting of lead azide, lead styphante aluminium (LSA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm. About 500 gm explosive mixture was prepared in laboratory and its explosive properties were tested in asbestos pipe of internal diameter 50 mm, 0.9mm wall thickness. The composition was also tested in Gl pipe of internal diameter 45 mm, 5 mm wall thickness. Blast performance test was studied in cement concrete block of compressive strength 180 -250 kg/cm2. The composition is not a mere admixture as individual component do not have the capacity to blast the above mentioned cement concrete block, and hence the composition is synergistic in nature. The following examples are given by way of illustration and should not be construed to limit the scope of the invention. Example 1 Ingredients Ammonium nitrate (oxidising agent) Coal powder* (reducing agent) Guar gum (reducing agent) Sodium nitrite (gassing agent) potassium dichromate (cross-linking agent) Percentage 92.0 6.4 0.8 0.4 0.4 ♦Moisture: 2.5 %, Volatile matter: 26 %, Ash: 18 %,Carbon: 53.5 % The test results of formulation no. 1 are listed in table 1. Example 2 Ingredients Ammonium nitrate (oxidising agent) Sodium nitrate (oxidising agent) Coal powder (reducing agent) Guar gum (reducing agent) Sodium nitrite (gassing agent) Potassium dichromate (cross-linking agent)Percentage 73.6 15.8 8.8 1.3 0.2 0.3 The test results of formulation no. 1 & 2 are listed in Table 1 The inference of properties of the composition of the present invention are: Tab 1e i Explosive properties of formulation 1 and formulation 2. 1. Density 2. Cap-sensitivity 3. Minimum diameter 4. Continuity of detonation 5. Detonation velocity 6. Impact sensitivity with 5 kg fall hammer 7. Detonation pressure 8. Strength (% BG) 9. Shelf life 0.9 to 1.1 gm/cm No. 6 detonator 40 mm in steel pipe Passed 2400 to 3000 m/sec. 2.0 to 3.0 kg 9.0 to 12.0 Khar 65 to 70 % BG Six months on storage The main advantages are: 1. The composition is cap-sensitive in 40 mm diameter. 2. It is sensitive with no. 6 detonator without using organic nitrate or metal powder like aluminium in atomised or flake. 3. The composition would be useful for rock blasting. We Claim: 1. A composition useful for quarry blasting and other excavation works which comprises an oxidizing agent selected from ammonium nitrate, sodium nitrate, calcium nitrate and potassium nitrate in the range of 85 to 95 wt %, reducing agent selected from coal powder/activated carbon and guar gum in the range of 5 to 10 wt%, a cross linking agent selected from potassium dichromate, potassium antimony tartrate in the range of 0.3 to 0.5 wt%, and a gassing agent such as sodium nitrite ffewi in the range of 0.3 to 0.4 wt% . 2. A composition as claimed in claim 1 wherein the oxidizing agent used is having purity 99% and particle size 3. A composition as claimed in claims 1-2 wherein reducing agent having purity of which being 90% and particle size being 4. A composition as claimed in claims 1-3 wherein cross linking agent and gassing agent used are of analytical grade and having 99% purity and particle size being 5. A composition useful for quarry blasting and other excavation works substantially as herein described with reference to the examples.

Documents:

2642-del-1996-abstract.pdf

2642-del-1996-claims.pdf

2642-del-1996-complete specifiction (granted).pdf

2642-del-1996-correspondence-others.pdf

2642-del-1996-correspondence-po.pdf

2642-del-1996-description (complete).pdf

2642-del-1996-form-1.pdf

2642-del-1996-form-19.pdf

2642-del-1996-form-2.pdf

2642-del-1996-form-3.pdf