Title of Invention	"A SYNERGISTIC COMPOSITION OF EMULSION EXPLOSIVE USEFUL FOR BLASTING IN SURFACE MINES AND A PROCESS OF MAKING THE EMULSION EXPLOSIVE"
Abstract	This invention relates to a synergistic composition of emulsion explosive useful for blasting in surface mines and a process for making the emulsion explosive. This synergistic composition is water-in oil site mixed emulsion explosive, booster sensitive and detonates in the 50mm, 83mm and larger sizes which can be used in shovel and deep hole blasting in surface mines. The velocity of detonation is in the range of 4500- 4800 m/s. The developed product is water resistant and sustain the hydrostatic pressure in deep bore holes up to 45m depths. The energy values of this product are in between 575 to 590 kcal/kg and enough for rock fragmentation in shovel as well as deep hole blasting. 25T

Title of Invention

"A SYNERGISTIC COMPOSITION OF EMULSION EXPLOSIVE USEFUL FOR BLASTING IN SURFACE MINES AND A PROCESS OF MAKING THE EMULSION EXPLOSIVE"

Abstract

This invention relates to a synergistic composition of emulsion explosive useful for blasting in surface mines and a process for making the emulsion explosive. This synergistic composition is water-in oil site mixed emulsion explosive, booster sensitive and detonates in the 50mm, 83mm and larger sizes which can be used in shovel and deep hole blasting in surface mines. The velocity of detonation is in the range of 4500- 4800 m/s. The developed product is water resistant and sustain the hydrostatic pressure in deep bore holes up to 45m depths. The energy values of this product are in between 575 to 590 kcal/kg and enough for rock fragmentation in shovel as well as deep hole blasting. 25T

Full Text	The following specification particularly describes the nature of the invention and the manner in which it is to be performed. This invention relates to a synergistic composition ?of emulsion explosive useful for blasting in surface mines and a process of making the emulsion explosive. This invention particularly relates to a novel water-in-oil Site Mixed Emulsion (SME) explosive composition which is booster sensitive and particularly suitable for shovel and deep hole blasting in surface mines and a process for making the emulsion explosive from the said novel composition. Site Mixed Emulsion (SME) explosives are water-in-oil emulsions which provide high interfacial contact between oxidizer and fuel, resulting in high degree of sensitivity and velocity of detonation. The velocity of detonation in site mixed emulsion explosives varies in the range of 3500 to 4500 m/s. These bulk explosives have short shelf life, have poor water resistance and low energy content which are not sufficient for rock fragmentation. The crystallization starts in the products within 7-8 days, which destabilizes the explosive and is the cause of poor end results. Nitroglycerine (NG) explosives are available for use in underground blasting and other rock excavation works. The velocity of detonation and detonation pressure are very high which causes safety problems. The density varies from 1.10 to 1.30 g/cm 3. Reference may be made to the Encyclopedia of Explosives Vol. 9, pp T415. The NG based explosives are highly sensitive to impact and friction, thus there is increased danger during operation. In India large diameter cartridge explosives are available in 83mm, 125 mm and 200 mm with different weights of 2.76 kg, 6.25 kg and 12.5 kg, respectively. These cartridge explosives are packed either in plastic tubes with copper clip or in blow molded tubes. Reference may be made to: Engineering Index Annual -1993, Vol. 92, Part III, Development in explosives (050974). These are cap non-sensitive compositions and the velocity of detonation varies from 3000 to 4500 m/sec in unconfined condition. There are a number of commercially available surface blasting explosives which are covered by patents. The details are as follows: In US Patent No. 5639988 / 1997, Michael Cechanski prepared a water-in-oil emulsion explosive which contained water immiscible organic fuel as the continuous phase and inorganic salt solution or melt as the discontinuous phase. The ammonium nitrate prill and solid bulking agent (Q-719 glass micro spheres from PQ Australia) was also added to increase the blast efficiency of the product. The density of the product was in between 1.15 to 1.30 g/cc. Reference may be made to ETI Canada Inc., © 1998-2000, wherein TOVEX ® BLASTRITE ™ 3 Rs is described as a cap sensitive cartridged water-gel explosive, specially designed for surface mines and is usable where high energy is required. It is available in 50 mm diameter cartridge and density of the product is 1.18 g/cc. The velocity of detonation reported was 4800 m/s. This product is acceptable for use under 24 metres hydrostatic pressure head or 241.32 kPa with a standard blasting cap. In the reference ETI Canada Inc., © 1998-2000, TOVEX ® EL- 930™ is another booster sensitive water-gel explosive designed for both surface mines and underground use and available in diameters of 50mm and larger. The density of the product is 1.30 g/cc and its velocity of detonation is 6000 m/s. The product having diameter in between 50 mm to 70 mm is used with 90 gram cast booster whereas diameter in between 75mm to 125mm the required booster charge is 150 gram. The diameters 125mm and up required 454 gram of cast booster. This product is acceptable for use under 30 metres (50psi) hydrostatic pressure head. The Canadian explosives referred herein above are available in 50 mm to 125 mm diameter and the velocity of detonation and detonation pressure of product are very high in the range of 4800 to 6000 m/sec, which is likely to cause ground vibration, back break and fly rock problem in blasting. The densities of the products were very high ranging from 1.15 to 1.30g/cm3, and in unconfined areas, such as surface blasting, it is generally found that explosives having density of above 1.25 g/cm3 misfire or detonate poorly. In our co-pending Indian Patent Application No. 2642/DEL/96, B. M. P. Pingua, M. Nabiullah and B. B. Dhar have described and claimed "A composition useful for excavation works". This is a cap sensitive coal based explosive composition for surface blasting under dry conditions. The composition claimed consists of: oxidizing agents in the range of 85 to 95 wt %, reducing agents in the range of 5 to 10 wt%, cross-linking agent in the range of 0.30 to 0.50 wt% and gassing agent in the range of 0.30 to 0.40 wt%. This explosive composition is in a powdery form and has poor water resistance. Therefore, it cannot be used for excavation work under watery conditions. In our another co-pending Indian Patent application No 3836/DEL/98, Jagdish, Nabiullah, B.M.P. Pingua and T.N. Singh have described and claimed "A composition useful for excavation works such as blasting in coal / non-coal surface mines". This is a booster sensitive emulsion explosive composition.The composition claimed consists of : oxidizing agent such as ammonium nitrate 73.79 to 74.67 wt%, reducing agent such as diesel 1.76 to 1.78 wt%, wax 2.02 to 2.04 wt%, urea 2.35 to 2.37 wt%, thio-urea 0.10 to 0.11 wt%, emulsifier such as sorbitan mono-oleate 1.58 to 1.60 wt%, gassing agent such as acrylamide 0.05 to 0.08 wt%, sodium nitrite 0.05 to 0.08 wt% and solvent for oxidizer such as water 18.00 to 19.00 wt%. This composition is suitable for shovel bench depth up to 15 to 20 m and has poor water resistant properties. The explosive compositions as described in our co-pending patent application numbers 2642 / DEL / 96 and 3836 / DEL / 98, are suitable for surface excavation, of upto 20m depths, by blasting, under non-watery conditions.These explosive compositions are not suitable for depths beyond 20m and may not give the desired results due to poor water resistance and for not having sufficient energy for rock fragmentation. The main object of the present invention is to provide a synergistic composition of emulsion explosive useful for blasting in surface mines, which obviates the above noted drawbacks. Another object of the present invention is to provide a novel emulsion explosive composition having excellent water resistant properties and sufficient energy for rock fragmentation, suitable for shovel and deep hole blasting in surface mines. Still another object of the present invention is to provide a synergistic composition for preparing an emulsion explosive having velocity of detonation in the range of 4500 to 4800 m/s, with shelf life of more than thirty days and explosion energy in the range of 575 to 590 kcal/kg which is sufficient to break the rock formations with proper fragmentation. Still yet another object of the present invention is to provide a novel explosive composition for preparing an emulsion explosive which would be booster- sensitive with 100 g cast booster, made of 50% PETN and 50% TNT. A further object of the present invention is to provide a process of making emulsion explosive from the novel explosive composition, which obviates the above noted drawbacks. Another object of the present invention is to provide bulk emulsion explosive for deep hole blasting up to 40 to 45m depths. The synergistic composition of emulsion explosive of the present invention provides a novel explosive with high velocity of detonation and available energy, which is booster sensitive in 50mm, 83mm diameter and larger. The product has excellent water resistant property and sustainable to high hydrostatic pressure head (5.5kg/cm2). The viscosity of the developed product is more than 60000 cps and in higher viscosity gassing is uniform and formed air bubbles works as sensitizer in bulk explosive, which provides the stability to the product. Higher viscosity helps in uniform gassing of the product and prevents it from dead density due to hydrostatic pressure load in bore hole. The sleepage period is more than thirty days. The composition of the present invention is safe in handling and non-hazardous during preparation. The synergistic composition for making emulsion explosive of the present invention utilizes ingredients of oxidizing phase (agents) such as ammonium nitrate, calcium nitrate and sodium nitrate, fuel phase (agents) such as light diesel oil, furnace oil and soya lecithin oil and emulsifier such as sorbitan mono-oleate, stabilizer such as thio-urea, water as solvent and gassing agent such as a mixture-solution of sodium nitrite and zinc nitrate. Particle of oxidizer salts such as ammonium nitrate prill is incorporated in the emulsion explosive to obtain zero oxygen balance to provide energy and stability to the explosive. The gassing agents such as a solution of a mixture of sodium nitrite and zinc nitrate incorporated in the emulsion explosive brings down the detonation density of the explosive to the range of 1.05 to 1.20g/cm3. Accordingly, the present invention provides a synergistic composition of emulsion explosive useful for blasting in surface mines, which comprises: (i) Oxidizing agent(s) such as: (a) Ammonium nitrate : 64.00 to' 72.00 wt%; (b) Calcium nitrate (hydrated): 8.50 to 12.00 wt%; (c) Sodium nitrate : 2.50 to 3.50 wt%; (ii) Fuel agent(s) such as: (a) Light diesel oil : 2.50 to 3.50 wt%; (b) Furnace oil : 2.00 to 2.50 wt %; (c) Soya lecithin oil : 0.20 to 0.30 wt%; (iii) Emulsifier : 0.90 to 1.10wt%; (iv) Stabilizer : 0.08 to 0.10wt%; (v) Gassing agent(s) :0.18 to 0.20 wt% and (vi) Solvent for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %. In an embodiment of the present invention the oxidizing agent(s) is such as ammonium nitrate, calcium nitrate (hydrated), sodium nitrate or mixture thereof. In another embodiment of the present invention the fuel agent(s) is such as light diesel oil, furnace oil, soya lecithin oil or mixture thereof. In yet another embodiment of the present invention the emulsifier is such as sorbitan mono-oleate. In still another embodiment of the present invention the stabilizer is such as thio-urea. In still yet another embodiment of the present invention the gassing agent is such as solution of sodium nitrite, zinc nitrate or mixture thereof. In a further embodiment of the present invention the solvent is such as water for oxidizer(s) and gassing agent(s). In an embodiment of the present invention, the oxidizing agent ammonium nitrate is in powder form and in particle form such as ammonium nitrate prill. In another embodiment of the present invention, the gassing agent is a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture : water of ratio 1:4. In a still further embodiment of the present invention the oxidizing agent(s) is of 99% purity. In another embodiment of the present invention the fuel agent(s) is of 98% purity. In yet another embodiment of the present invention the emulsifier is of 99 % purity. In still another embodiment of the present invention the stabilizer is of 99 % purity. In still yet another embodiment of the present invention the gassing agent(s) is of 99 % purity. In an embodiment of the present invention there is provided a synergistic composition of emulsion explosive useful for blasting in surface mines, which comprises: (i) Oxidizing agent(s) such as: (a)(l) Ammonium nitrate : 55.00 to 56.50 wt%; (a)(2) Oxidizer salt particles such as: Ammonium nitrate prill : 9.00 to 15.50 wt%; (b) Calcium nitrate (hydrated) : 8.50 to. 12.00wt%; (c) Sodium nitrate : 2.50 to 3.50 wt%; (ii) Fuel agent(s) such as: (a) Light diesel oil : 2.50 to 3.50 wt %; (b) Furnace oil : 2.00 to 2.50 wt %; (c) Soya lecithin oil : 0.20 to 0.30 wt%; (iii) Emulsifier such as sorbitan mono-oleate : 0.90 to 1.10 wt%; (iv) Stabilizer such as thio-urea : 0.08 to 0.10 wt%; (v) Gassing agent(s) such as: Sodium nitrite and zinc nitrate : 0.18 to 0.20 wt% and (vi) Solvent such as: Water for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %. It is a feature of the present invention that the.composition is not a mere admixture but a synergistic mixture having properties which are distinct and different to the mere aggregation of the properties of the individual ingredients and there is no chemical reaction in the composition. Accordingly the present invention provides a process for making emulsion explosive from the synergistic composition of the present invention, which comprises: (a) dissolving oxidizing agents and stabilizer in water at 65 - 75 °C and maintaining pH of the solution in the range 4.00 to 4.50 by adding acid/base to obtain an oxidizer solution; (b) heating fuel agents and emulsifier under stirring at a temperature of around 60 to 62°C to obtain a fuel phase; (c) adding the oxidizer solution obtained in step (a) to the fuel phase obtained in step (b) under stirring at a speed in the range of 3500 to 4000 rpm to obtain an emulsion matrix having negative oxygen balance; (d) adding to the said emulsion matrix obtained in step (c), oxidizer salt in particle form, such as ammonium nitrate prill, to obtain an emulsion matrix with near zero oxygen balance; (e) adding to the resultant emulsion matrix obtained in step (d), gassing agent such as a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture : water of ratio 1:4. In an embodiment of the present invention the pH of the oxidizer solution is maintained in the range 4.00 to 4.50 by adding acid/base such as sulphamic acid, nitric acid, sodium bicarbonate. In another embodiment of the present invention the oxidizing solution is added to the fuel phase at a temperature of around 60 to 62 °C. In yet another embodiment of the present invention the oxidizer salt in particle form, such as ammonium nitrate prill, is added to the emulsion matrix at a temperature of around 45 to 50°C. In still another embodiment of the present invention 7 to 8 ml of the gassing agents solution is added per kilogram of the product to achieve detonation density in the range 1.05 to 1.20g/cm3 at around 40-45°C. In the process of the present invention oxidizing agents and stabilizer were first taken with water and heated up to 65-75°C and pH of the solution was maintained in between 4.00 to 4.50 by adding acid / base. In another container fuel phase and emulsifier such as light diesel oil, furnace oil, soya lecithin and sorbitan mono-oleate were heated at a temperature of around 60-62°C. It was stirred first in slow speed and when stirring speed was in between 3500 to 4000 rpm the already prepared oxidizer solution was added to the separately prepared fuel phase to obtain an emulsion matrix. Emulsion matrix thus formed was in negative oxygen balance. To attain the desired zero oxygen balance, particles of oxidizer salt such as ammonium nitrate prill was added to the emulsion matrix, at a temperature of in between 45-50°C, to get near zero oxygen balance. The gassing agents such as 1:1 mixture of sodium nitrite and zinc nitrate was dissolved in water to prepare 1:4 solution. 7 to 8 ml of this solution was added to per kilogram of the emulsion explosive to achieve a detonation density in the range of 1.05 to 1.20g/cm3 at around 40-45°C. The composition prepared is booster sensitized (lOOg cast booster) enough to be initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm. A comparative table showing details of ingredients in our co-pending patent numbers 2642 / DEL/ 96 and 3836 / DEL / 98 with the emulsion explosive composition of the present invention is given in table 1 below. Table 1 (Table Removed) In our co-pending patent numbers 2642 / DEL/ 96 and 3836 / DEL / 98,the explosive compositions failed to detonate in above 20m depths due to poor water resistance and for not having sufficient energy for rock fragmentation, where as the novel emulsion explosive composition of the present invention provides sufficient energy for rock fragmentation up to 45m depths with excellent water resistant properties. The following examples are given by way of illustration and should not be construed to limit the scope of the present invention. Example 1 A synergistic composition of emulsion explosive, as used in this experiment is given below in table - 1: Table -1(Table Removed) The oxidizing agents, ammonium nitrate (1254g), hydrated calcium nitrate (258g), sodium nitrate (60g) and stabilizer, thio-urea (2g), were dissolved in required quantity of water (290g) at 70 ° C to obtain an oxidizer solution. The pH of the solution was maintained by adding sulphamic acid at 4.0. The fuel agents, light diesel oil (60g), furnace oil (49g), soya lecithin oil (6g) and emulsifier, sorbitan mono-oleate (21g) were heated in a separate container at 60°C to obtain a fuel phase. The fuel phase so obtained was stirred slowly first and the already prepared oxidizer solution was added to the fuel phase under stirring at high speed of 3500 rpm to obtain an emulsion matrix having negative oxygen balance. To get near to zero oxygen balance in the emulsion matrix, oxidizer salt in particle form, ammonium nitrate prill (200g), was added to the emulsion matrix. A 1:1 mixture of gassing agents, sodium nitrite (lOg) and zinc nitrate (lOg), was dissolved in 80 ml water and 16ml .of this prepared solution (consisting of 16 ml water, 2g sodium nitrite & 2g zinc nitrate) was used in the treatment of gassing which brought down the product detonation density to 1.12. In a single batch, 2220g of emulsion explosive was prepared from the composition as detailed in table - 1 above. The prepared explosive was packed in 83mm diameter polythene tube and was initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm. The velocity of detonation measured by Dautriche method was 4500m/s. The viscosity of the emulsion matrix was measured with the help of Brookfleld viscometer and found to be 62000 cps at 40°C. Velocity of detonation at shallow water test and hydrostatic pressure (4 kg/cm2) tests were found to be 4000m/s and 3800 m/s, respectively. lOkg.of weight was dropped by the fall hammer method from a height of 3m and it was observed that there was no detonation behavior in the explosive. The available energy, which consists of shock and gas pressure, was measured with the help of under water blasting method and found to be 575 kcal/kg. The detonation behavior of the composition was tested for a period of more than thirty days and detonation was found to be satisfactory even after thirty days of storage period. The explosive properties of the emulsion explosive prepared in Example 1 are given in table - 2 below: Table-2 (Table Removed) Example 2 A synergistic composition of emulsion explosive, as used in this experiment is given below in table - 3: Table - 3(Table Removed) The oxidizing agents, ammonium nitrate. (1320g), hydrated calcium nitrate (212g), sodium nitrate (70g) and stabilizer, thio-urea, were dissolved in required quantity of water(248g) at 75 ° C. The pH of the solution was maintained at 4.5 by adding nitric acid. The fuel agents, light diesel oil (70g), furnace oil (50.4g), soya lecithin oil (5.2g) and emulsifier, sorbitan mono-oleate (22.4g), were heated in a separate container at 62°C to obtain a fuel phase. It was first stirred slowly and the oxidizer solution was added to the fuel phase under stirring at high speed of 4000 rpm. The emulsion matrix so obtained was of negative oxygen balanced form. To get near to zero oxygen balance in the emulsion matrix, oxidizer salt in particle form, ammonium nitrate prill (360g), was added to the emulsion matrix. A 1:1 mixture of gassing agents, sodium nitrite (lOg) and zinc nitrate (lOg), was dissolved in 80 ml water and 18ml of this prepared solution (consisting of 18 ml water, 2.25g sodium nitrite & 2.25g zinc nitrate) was used in the treatment of gassing which brought down the product detonation density to 1.08. In a single batch 2382.5g of emulsion explosive was prepared from the composition as detailed in table - 3 above. The prepared explosive was packed in 83mm diameter polythene tube and was initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm. The velocity of detonation measured by Dautriche method was 4800m/s. The viscosity of the emulsion matrix was measured with the help of Brookfield viscometer and found to be 68000 cps at 40°C. Velocity of detonation at shallow water test and hydrostatic pressure (5.5 kg/cm2) tests were found to be 4500m/s and 4000 m/s, respectively. lOkg.of weight was dropped by the fall hammer method from a height of 3m and it was observed that there was no detonation behavior in the explosive. The available energy, which consists of shock and gas pressure, was measured with the help of under water blasting method and found to be 590 kcal/kg. The detonation behavior of the composition was tested for a period of more than thirty days and detonation was found to be satisfactory even after thirty days of storage period. The explosive properties of the emulsion explosive prepared in Example 2 are given in table - 4 below: Table - 4(Table Removed) The characteristic explosive properties of the emulsion explosive based on the novel compositions as detailed in the examples 1 and 2 are tabulated below: Table – 5 (Table Removed) The main advantages of the emulsion explosive composition of the present invention are: 1. It is a booster sensitive composition in 50mm, 83mm diameter and larger. 2. The composition would be useful for shovel and deep hole blasting. 3. It has excellent water-resistant VOD in the range of 4000-4500 m/s. 4. The product is acceptable for use under 45m hydrostatic pressure head (5.5 kg/cm2) 5. The shelf life of the synergistic composition is more than thirty days. 6. It is an economically viable emulsion explosive composition. 7. It is non-hazardous and safe in handling. We claim: 1. A synergistic composition of emulsion explosive useful for blasting in surface mines, which comprises: (i) Oxidizing agent(s) : (a) Ammonium nitrate : 64.00 to 72.00 wt %; (b) Calcium nitrate (hydrated): 8.50 to 12.00 wt%; (c) Sodium nitrate : 2.50 to 3.50 wt%; (ii) Fuel agent(s) : (a) Light diesel oil : 2.50 to 3.50 wt %; (b) Furnace oil : 2.00 to 2.50 wt %; (c) Soya lecithin oil : 0.20 to 0.30 wt%; (iii) Emulsifier : 0.90 to 1.10 wt%; (iv) Stabilizer : 0.08 to 0.10 wt%; (v) Gassing agent(s) :0.18 to 0.20 wt% and (vi) Solvent for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %. 2. A synergistic composition as claimed in claim 1, wherein the oxidizing agent(s) is ammonium nitrate, calcium nitrate (hydrated), sodium nitrate or mixture thereof. 3. A synergistic composition as claimed in claim 1-2, wherein the fuel agent(s) is light diesel oil, furnace oil, soya lecithin oil or mixture thereof. 4. A synergistic composition as claimed in claim 1-3, wherein the emulsifier is sorbitan mono-oleate. 5. A synergistic composition as claimed in claim 1-4, wherein the stabilizer is thio-urea. 6. A synergistic composition as claimed in claim 1-5, wherein the gassing agent is a solution of sodium nitrite, zinc nitrate or mixture thereof. 7. A synergistic composition as claimed in claim 1-6, wherein the solvent is water for oxidizer(s) and gassing agent(s). 8. A synergistic composition as claimed in claim 1-7, wherein the gassing agent is a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture to water of ratio 1:4. 9. A synergistic composition as claimed in claim 1-8, wherein the oxidizing agent ammonium nitrate is in powder form and in particle form such as ammonium nitrate prill. 10. A synergistic composition as claimed in claim 1-9, wherein the oxidizing agent(s), emulsifier , stabilizer and gassing agent(s) is of 99% purity. 11. A synergistic composition as claimed in claim 1-9, wherein the fuel agent(s), is of 98% purity. 12. A process for making emulsion explosive from the synergistic composition as claimed in claim 1-11, which comprises: (a) dissolving oxidizing agents and stabilizer in water at 65 - 75 °C and maintaining pH of the solution in the range 4.00 to 4.50 by adding acid/base to obtain an oxidizer solution; (b) heating fuel agents and emulsifier under stirring at a temperature of around 60 to 62°C to obtain a fuel phase; (c) adding the oxidizer solution obtained in step (a) to the fuel phase obtained in step (b) under stirring at a speed in the range of 3500 to 4000 rpm to obtain an emulsion matrix having negative oxygen balance; (d) adding to the said emulsion matrix obtained in step (c), oxidizer salt in particle form, such as ammonium nitrate prill, to obtain an emulsion matrix with near zero oxygen balance; (e) adding to the resultant emulsion matrix obtained in step (d), gassing agent such as a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture : water of ratio 1:4. 13. A process for making emulsion explosive as claimed in claim 12, wherein the pH of the oxidizer solution is maintained in the range 4.00 to 4.50 by adding acid/base such as sulphamic acid, nitric acid, sodium bicarbonate. 14. A process for making emulsion explosive as claimed in claim 12-13, wherein the oxidizing solution is added to the fuel phase at a temperature of around 60 to 62 °C. 15. A process for making emulsion explosive as claimed in claim 12-14, wherein the oxidizer salt in particle form, such as ammonium nitrate prill, is added to the emulsion matrix at a temperature of around 45 to 50 C. 16. A process for making emulsion explosive as claimed in claim 12-15, wherein 7 to 8 ml of the gassing agents solution is added per kilogram of the product to achieve detonation density in the range 1.05 to 1.20g/cm at around 40-45 C. 21. A synergistic composition of emulsion explosive useful for blasting in surface mines, and a process for making emulsion explosive substantially as herein described with reference to the examples.

Full Text

The following specification particularly describes the nature of the invention and the manner in which it is to be performed.
This invention relates to a synergistic composition ?of emulsion explosive useful for blasting in surface mines and a process of making the emulsion explosive.
This invention particularly relates to a novel water-in-oil Site Mixed Emulsion (SME) explosive composition which is booster sensitive and particularly suitable for shovel and deep hole blasting in surface mines and a process for making the emulsion explosive from the said novel composition.
Site Mixed Emulsion (SME) explosives are water-in-oil emulsions which provide high interfacial contact between oxidizer and fuel, resulting in high degree of sensitivity and velocity of detonation. The velocity of detonation in site mixed emulsion explosives varies in the range of 3500 to 4500 m/s. These bulk explosives have short shelf life, have poor water resistance and low energy content which are not sufficient for rock fragmentation. The crystallization starts in the products within 7-8 days, which destabilizes the explosive and is the cause of poor end results.
Nitroglycerine (NG) explosives are available for use in underground blasting and other rock excavation works. The velocity of detonation and detonation pressure are very high which causes safety problems. The density varies from 1.10 to 1.30 g/cm 3. Reference may be made to the Encyclopedia of Explosives Vol. 9, pp T415. The NG based explosives are highly sensitive to impact and friction, thus there is increased danger during operation.
In India large diameter cartridge explosives are available in 83mm, 125 mm and 200 mm with different weights of 2.76 kg, 6.25 kg and 12.5 kg, respectively. These cartridge explosives are packed either in plastic tubes with

copper clip or in blow molded tubes. Reference may be made to: Engineering Index Annual -1993, Vol. 92, Part III, Development in explosives (050974). These are cap non-sensitive compositions and the velocity of detonation varies from 3000 to 4500 m/sec in unconfined condition.
There are a number of commercially available surface blasting explosives which are covered by patents. The details are as follows:
In US Patent No. 5639988 / 1997, Michael Cechanski prepared a water-in-oil emulsion explosive which contained water immiscible organic fuel as the continuous phase and inorganic salt solution or melt as the discontinuous phase. The ammonium nitrate prill and solid bulking agent (Q-719 glass micro spheres from PQ Australia) was also added to increase the blast efficiency of the product. The density of the product was in between 1.15 to 1.30 g/cc.
Reference may be made to ETI Canada Inc., © 1998-2000, wherein TOVEX ® BLASTRITE ™ 3 Rs is described as a cap sensitive cartridged water-gel explosive, specially designed for surface mines and is usable where high energy is required. It is available in 50 mm diameter cartridge and density of the product is 1.18 g/cc. The velocity of detonation reported was 4800 m/s. This product is acceptable for use under 24 metres hydrostatic pressure head or 241.32 kPa with a standard blasting cap.
In the reference ETI Canada Inc., © 1998-2000, TOVEX ® EL- 930™ is another booster sensitive water-gel explosive designed for both surface mines and underground use and available in diameters of 50mm and larger. The density of the product is 1.30 g/cc and its velocity of detonation is 6000 m/s. The product having diameter in between 50 mm to 70 mm is used with 90 gram cast booster whereas diameter in between 75mm to 125mm the required booster charge is 150 gram. The diameters 125mm and up required 454 gram of cast

booster. This product is acceptable for use under 30 metres (50psi) hydrostatic pressure head.
The Canadian explosives referred herein above are available in 50 mm to 125 mm diameter and the velocity of detonation and detonation pressure of product are very high in the range of 4800 to 6000 m/sec, which is likely to cause ground vibration, back break and fly rock problem in blasting. The densities of the products were very high ranging from 1.15 to 1.30g/cm3, and in unconfined areas, such as surface blasting, it is generally found that explosives having density of above 1.25 g/cm3 misfire or detonate poorly.
In our co-pending Indian Patent Application No. 2642/DEL/96, B. M. P. Pingua, M. Nabiullah and B. B. Dhar have described and claimed "A composition useful for excavation works". This is a cap sensitive coal based explosive composition for surface blasting under dry conditions. The composition claimed consists of: oxidizing agents in the range of 85 to 95 wt %, reducing agents in the range of 5 to 10 wt%, cross-linking agent in the range of 0.30 to 0.50 wt% and gassing agent in the range of 0.30 to 0.40 wt%. This explosive composition is in a powdery form and has poor water resistance. Therefore, it cannot be used for excavation work under watery conditions.
In our another co-pending Indian Patent application No 3836/DEL/98, Jagdish, Nabiullah, B.M.P. Pingua and T.N. Singh have described and claimed "A composition useful for excavation works such as blasting in coal / non-coal surface mines". This is a booster sensitive emulsion explosive composition.The composition claimed consists of : oxidizing agent such as ammonium nitrate 73.79 to 74.67 wt%, reducing agent such as diesel 1.76 to 1.78 wt%, wax 2.02 to 2.04 wt%, urea 2.35 to 2.37 wt%, thio-urea 0.10 to 0.11 wt%, emulsifier such as sorbitan mono-oleate 1.58 to 1.60 wt%, gassing agent such as acrylamide 0.05 to

0.08 wt%, sodium nitrite 0.05 to 0.08 wt% and solvent for oxidizer such as water 18.00 to 19.00 wt%. This composition is suitable for shovel bench depth up to 15 to 20 m and has poor water resistant properties.
The explosive compositions as described in our co-pending patent application numbers 2642 / DEL / 96 and 3836 / DEL / 98, are suitable for surface excavation, of upto 20m depths, by blasting, under non-watery conditions.These explosive compositions are not suitable for depths beyond 20m and may not give the desired results due to poor water resistance and for not having sufficient energy for rock fragmentation.
The main object of the present invention is to provide a synergistic composition of emulsion explosive useful for blasting in surface mines, which obviates the above noted drawbacks.
Another object of the present invention is to provide a novel emulsion explosive composition having excellent water resistant properties and sufficient energy for rock fragmentation, suitable for shovel and deep hole blasting in surface mines.
Still another object of the present invention is to provide a synergistic composition for preparing an emulsion explosive having velocity of detonation in the range of 4500 to 4800 m/s, with shelf life of more than thirty days and explosion energy in the range of 575 to 590 kcal/kg which is sufficient to break the rock formations with proper fragmentation.
Still yet another object of the present invention is to provide a novel explosive composition for preparing an emulsion explosive which would be booster- sensitive with 100 g cast booster, made of 50% PETN and 50% TNT.

A further object of the present invention is to provide a process of making emulsion explosive from the novel explosive composition, which obviates the above noted drawbacks.
Another object of the present invention is to provide bulk emulsion explosive for deep hole blasting up to 40 to 45m depths.
The synergistic composition of emulsion explosive of the present invention provides a novel explosive with high velocity of detonation and available energy, which is booster sensitive in 50mm, 83mm diameter and larger. The product has excellent water resistant property and sustainable to high hydrostatic pressure head (5.5kg/cm2). The viscosity of the developed product is more than 60000 cps and in higher viscosity gassing is uniform and formed air bubbles works as sensitizer in bulk explosive, which provides the stability to the product. Higher viscosity helps in uniform gassing of the product and prevents it from dead density due to hydrostatic pressure load in bore hole. The sleepage period is more than thirty days. The composition of the present invention is safe in handling and non-hazardous during preparation.
The synergistic composition for making emulsion explosive of the present invention utilizes ingredients of oxidizing phase (agents) such as ammonium nitrate, calcium nitrate and sodium nitrate, fuel phase (agents) such as light diesel oil, furnace oil and soya lecithin oil and emulsifier such as sorbitan mono-oleate, stabilizer such as thio-urea, water as solvent and gassing agent such as a mixture-solution of sodium nitrite and zinc nitrate. Particle of oxidizer salts such as ammonium nitrate prill is incorporated in the emulsion explosive to obtain

zero oxygen balance to provide energy and stability to the explosive. The gassing agents such as a solution of a mixture of sodium nitrite and zinc nitrate incorporated in the emulsion explosive brings down the detonation density of the explosive to the range of 1.05 to 1.20g/cm3.
Accordingly, the present invention provides a synergistic composition of emulsion explosive useful for blasting in surface mines, which comprises: (i) Oxidizing agent(s) such as:
(a) Ammonium nitrate : 64.00 to' 72.00 wt%;
(b) Calcium nitrate (hydrated): 8.50 to 12.00 wt%;
(c) Sodium nitrate : 2.50 to 3.50 wt%;
(ii) Fuel agent(s) such as:

(a) Light diesel oil : 2.50 to 3.50 wt%;
(b) Furnace oil : 2.00 to 2.50 wt %;
(c) Soya lecithin oil : 0.20 to 0.30 wt%;
(iii) Emulsifier : 0.90 to 1.10wt%;
(iv) Stabilizer : 0.08 to 0.10wt%;
(v) Gassing agent(s) :0.18 to 0.20 wt% and
(vi) Solvent for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %.
In an embodiment of the present invention the oxidizing agent(s) is such as ammonium nitrate, calcium nitrate (hydrated), sodium nitrate or mixture thereof.
In another embodiment of the present invention the fuel agent(s) is such as light diesel oil, furnace oil, soya lecithin oil or mixture thereof.
In yet another embodiment of the present invention the emulsifier is such as sorbitan mono-oleate.

In still another embodiment of the present invention the stabilizer is such as thio-urea.
In still yet another embodiment of the present invention the gassing agent is such as solution of sodium nitrite, zinc nitrate or mixture thereof.
In a further embodiment of the present invention the solvent is such as water for oxidizer(s) and gassing agent(s).
In an embodiment of the present invention, the oxidizing agent ammonium nitrate is in powder form and in particle form such as ammonium nitrate prill.
In another embodiment of the present invention, the gassing agent is a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture : water of ratio 1:4.
In a still further embodiment of the present invention the oxidizing agent(s) is of 99% purity.
In another embodiment of the present invention the fuel agent(s) is of 98% purity.
In yet another embodiment of the present invention the emulsifier is of 99 % purity.
In still another embodiment of the present invention the stabilizer is of 99 % purity.
In still yet another embodiment of the present invention the gassing agent(s) is of 99 % purity.
In an embodiment of the present invention there is provided a synergistic composition of emulsion explosive useful for blasting in surface mines, which comprises: (i) Oxidizing agent(s) such as:

(a)(l) Ammonium nitrate : 55.00 to 56.50 wt%;
(a)(2) Oxidizer salt particles such as:
Ammonium nitrate prill : 9.00 to 15.50 wt%;
(b) Calcium nitrate (hydrated) : 8.50 to. 12.00wt%;
(c) Sodium nitrate : 2.50 to 3.50 wt%;
(ii) Fuel agent(s) such as:

(a) Light diesel oil : 2.50 to 3.50 wt %;
(b) Furnace oil : 2.00 to 2.50 wt %;
(c) Soya lecithin oil : 0.20 to 0.30 wt%;
(iii) Emulsifier such as sorbitan mono-oleate : 0.90 to 1.10 wt%;
(iv) Stabilizer such as thio-urea : 0.08 to 0.10 wt%;
(v) Gassing agent(s) such as:
Sodium nitrite and zinc nitrate : 0.18 to 0.20 wt% and
(vi) Solvent such as:
Water for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %.
It is a feature of the present invention that the.composition is not a mere admixture but a synergistic mixture having properties which are distinct and different to the mere aggregation of the properties of the individual ingredients and there is no chemical reaction in the composition.
Accordingly the present invention provides a process for making emulsion explosive from the synergistic composition of the present invention, which comprises:
(a) dissolving oxidizing agents and stabilizer in water at 65 - 75 °C and maintaining pH of the solution in the range 4.00 to 4.50 by adding acid/base to obtain an oxidizer solution;

(b) heating fuel agents and emulsifier under stirring at a temperature of
around 60 to 62°C to obtain a fuel phase;
(c) adding the oxidizer solution obtained in step (a) to the fuel phase
obtained in step (b) under stirring at a speed in the range of 3500 to 4000
rpm to obtain an emulsion matrix having negative oxygen balance;
(d) adding to the said emulsion matrix obtained in step (c), oxidizer salt in
particle form, such as ammonium nitrate prill, to obtain an emulsion
matrix with near zero oxygen balance;
(e) adding to the resultant emulsion matrix obtained in step (d), gassing
agent such as a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous
solution of mixture : water of ratio 1:4.
In an embodiment of the present invention the pH of the oxidizer solution is maintained in the range 4.00 to 4.50 by adding acid/base such as sulphamic acid, nitric acid, sodium bicarbonate.
In another embodiment of the present invention the oxidizing solution is added to the fuel phase at a temperature of around 60 to 62 °C.
In yet another embodiment of the present invention the oxidizer salt in particle form, such as ammonium nitrate prill, is added to the emulsion matrix at a temperature of around 45 to 50°C.
In still another embodiment of the present invention 7 to 8 ml of the gassing agents solution is added per kilogram of the product to achieve detonation density in the range 1.05 to 1.20g/cm3 at around 40-45°C.
In the process of the present invention oxidizing agents and stabilizer were first taken with water and heated up to 65-75°C and pH of the solution was maintained in between 4.00 to 4.50 by adding acid / base. In another container
fuel phase and emulsifier such as light diesel oil, furnace oil, soya lecithin and sorbitan mono-oleate were heated at a temperature of around 60-62°C. It was stirred first in slow speed and when stirring speed was in between 3500 to 4000 rpm the already prepared oxidizer solution was added to the separately prepared fuel phase to obtain an emulsion matrix. Emulsion matrix thus formed was in negative oxygen balance. To attain the desired zero oxygen balance, particles of oxidizer salt such as ammonium nitrate prill was added to the emulsion matrix, at a temperature of in between 45-50°C, to get near zero oxygen balance. The gassing agents such as 1:1 mixture of sodium nitrite and zinc nitrate was dissolved in water to prepare 1:4 solution. 7 to 8 ml of this solution was added to per kilogram of the emulsion explosive to achieve a detonation density in the range of 1.05 to 1.20g/cm3 at around 40-45°C.
The composition prepared is booster sensitized (lOOg cast booster) enough to be initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm.
A comparative table showing details of ingredients in our co-pending patent numbers 2642 / DEL/ 96 and 3836 / DEL / 98 with the emulsion explosive composition of the present invention is given in table 1 below.
Table 1
(Table Removed)
In our co-pending patent numbers 2642 / DEL/ 96 and 3836 / DEL / 98,the explosive compositions failed to detonate in above 20m depths due to poor water resistance and for not having sufficient energy for rock fragmentation, where as the novel emulsion explosive composition of the present invention provides sufficient energy for rock fragmentation up to 45m depths with excellent water resistant properties.
The following examples are given by way of illustration and should not be construed to limit the scope of the present invention.
Example 1
A synergistic composition of emulsion explosive, as used in this experiment is given below in table - 1:
Table -1(Table Removed)
The oxidizing agents, ammonium nitrate (1254g), hydrated calcium nitrate (258g), sodium nitrate (60g) and stabilizer, thio-urea (2g), were dissolved in required quantity of water (290g) at 70 ° C to obtain an oxidizer solution. The pH of the solution was maintained by adding sulphamic acid at 4.0. The fuel agents, light diesel oil (60g), furnace oil (49g), soya lecithin oil (6g) and emulsifier, sorbitan mono-oleate (21g) were heated in a separate container at 60°C to obtain a fuel phase. The fuel phase so obtained was stirred slowly first and the already prepared oxidizer solution was added to the fuel phase under stirring at high speed of 3500 rpm to obtain an emulsion matrix having negative oxygen balance. To get near to zero oxygen balance in the emulsion matrix, oxidizer salt in particle form, ammonium nitrate prill (200g), was added to the emulsion matrix. A 1:1 mixture of gassing agents, sodium nitrite (lOg) and zinc nitrate (lOg), was dissolved in 80 ml water and 16ml .of this prepared solution (consisting of 16 ml water, 2g sodium nitrite & 2g zinc nitrate) was used in the

treatment of gassing which brought down the product detonation density to
1.12.
In a single batch, 2220g of emulsion explosive was prepared from the
composition as detailed in table - 1 above.
The prepared explosive was packed in 83mm diameter polythene tube and was initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm.
The velocity of detonation measured by Dautriche method was 4500m/s. The viscosity of the emulsion matrix was measured with the help of Brookfleld viscometer and found to be 62000 cps at 40°C. Velocity of detonation at shallow water test and hydrostatic pressure (4 kg/cm2) tests were found to be 4000m/s and 3800 m/s, respectively. lOkg.of weight was dropped by the fall hammer method from a height of 3m and it was observed that there was no detonation behavior in the explosive. The available energy, which consists of shock and gas pressure, was measured with the help of under water blasting method and found to be 575 kcal/kg. The detonation behavior of the composition was tested for a period of more than thirty days and detonation was found to be satisfactory even after thirty days of storage period.
The explosive properties of the emulsion explosive prepared in Example 1 are given in table - 2 below:
Table-2

(Table Removed)
Example 2
A synergistic composition of emulsion explosive, as used in this experiment is given below in table - 3:
Table - 3(Table Removed)
The oxidizing agents, ammonium nitrate. (1320g), hydrated calcium nitrate (212g), sodium nitrate (70g) and stabilizer, thio-urea, were dissolved in required quantity of water(248g) at 75 ° C. The pH of the solution was maintained at 4.5 by adding nitric acid. The fuel agents, light diesel oil (70g), furnace oil (50.4g), soya lecithin oil (5.2g) and emulsifier, sorbitan mono-oleate (22.4g), were heated in a separate container at 62°C to obtain a fuel phase. It was first stirred slowly and the oxidizer solution was added to the fuel phase under stirring at high speed of 4000 rpm. The emulsion matrix so obtained was of negative oxygen balanced form. To get near to zero oxygen balance in the emulsion matrix, oxidizer salt in particle form, ammonium nitrate prill (360g), was added to the emulsion matrix. A 1:1 mixture of gassing agents, sodium nitrite (lOg) and zinc nitrate (lOg), was dissolved in 80 ml water and 18ml of this prepared solution (consisting of 18 ml water, 2.25g sodium nitrite & 2.25g zinc nitrate) was used in the treatment of gassing which brought down the product
detonation density to 1.08. In a single batch 2382.5g of emulsion explosive was prepared from the composition as detailed in table - 3 above.
The prepared explosive was packed in 83mm diameter polythene tube and was initiated with copper detonator (No.6) consisting of lead azide, lead styphante, aluminium (ASA) 0.20 gm and pentaerythritol tetranitrate (PETN) 0.22 gm.
The velocity of detonation measured by Dautriche method was 4800m/s. The viscosity of the emulsion matrix was measured with the help of Brookfield viscometer and found to be 68000 cps at 40°C. Velocity of detonation at shallow water test and hydrostatic pressure (5.5 kg/cm2) tests were found to be 4500m/s and 4000 m/s, respectively. lOkg.of weight was dropped by the fall hammer method from a height of 3m and it was observed that there was no detonation behavior in the explosive. The available energy, which consists of shock and gas pressure, was measured with the help of under water blasting method and found to be 590 kcal/kg. The detonation behavior of the composition was tested for a period of more than thirty days and detonation was found to be satisfactory even after thirty days of storage period.
The explosive properties of the emulsion explosive prepared in Example 2 are given in table - 4 below:
Table - 4(Table Removed)
The characteristic explosive properties of the emulsion explosive based on the novel compositions as detailed in the examples 1 and 2 are tabulated below:
Table – 5 (Table Removed)
The main advantages of the emulsion explosive composition of the present invention are:
1. It is a booster sensitive composition in 50mm, 83mm diameter and larger.
2. The composition would be useful for shovel and deep hole blasting.
3. It has excellent water-resistant VOD in the range of 4000-4500 m/s.
4. The product is acceptable for use under 45m hydrostatic pressure head (5.5 kg/cm2)
5. The shelf life of the synergistic composition is more than thirty days.
6. It is an economically viable emulsion explosive composition.
7. It is non-hazardous and safe in handling.

We claim:
1. A synergistic composition of emulsion explosive useful for blasting in surface
mines, which comprises:
(i) Oxidizing agent(s) :
(a) Ammonium nitrate : 64.00 to 72.00 wt %;
(b) Calcium nitrate (hydrated): 8.50 to 12.00 wt%;
(c) Sodium nitrate : 2.50 to 3.50 wt%; (ii) Fuel agent(s) :

(a) Light diesel oil : 2.50 to 3.50 wt %;
(b) Furnace oil : 2.00 to 2.50 wt %;
(c) Soya lecithin oil : 0.20 to 0.30 wt%; (iii) Emulsifier : 0.90 to 1.10 wt%; (iv) Stabilizer : 0.08 to 0.10 wt%; (v) Gassing agent(s) :0.18 to 0.20 wt% and (vi) Solvent for oxidizer(s) & gassing agent(s) : 11.00 to 14.50 wt %.
2. A synergistic composition as claimed in claim 1, wherein the oxidizing
agent(s) is ammonium nitrate, calcium nitrate (hydrated), sodium nitrate or
mixture thereof.
3. A synergistic composition as claimed in claim 1-2, wherein the fuel agent(s) is light diesel oil, furnace oil, soya lecithin oil or mixture thereof.
4. A synergistic composition as claimed in claim 1-3, wherein the emulsifier is sorbitan mono-oleate.
5. A synergistic composition as claimed in claim 1-4, wherein the stabilizer is thio-urea.
6. A synergistic composition as claimed in claim 1-5, wherein the gassing agent is a solution of sodium nitrite, zinc nitrate or mixture thereof.
7. A synergistic composition as claimed in claim 1-6, wherein the solvent is water for oxidizer(s) and gassing agent(s).
8. A synergistic composition as claimed in claim 1-7, wherein the gassing agent is a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture to water of ratio 1:4.
9. A synergistic composition as claimed in claim 1-8, wherein the oxidizing agent ammonium nitrate is in powder form and in particle form such as ammonium nitrate prill.

10. A synergistic composition as claimed in claim 1-9, wherein the oxidizing agent(s), emulsifier , stabilizer and gassing agent(s) is of 99% purity.
11. A synergistic composition as claimed in claim 1-9, wherein the fuel agent(s),
is of 98% purity.
12. A process for making emulsion explosive from the synergistic composition
as claimed in claim 1-11, which comprises:
(a) dissolving oxidizing agents and stabilizer in water at 65 - 75 °C and maintaining pH of the solution in the range 4.00 to 4.50 by adding acid/base to obtain an oxidizer solution;
(b) heating fuel agents and emulsifier under stirring at a temperature of around 60 to 62°C to obtain a fuel phase;
(c) adding the oxidizer solution obtained in step (a) to the fuel phase obtained in step (b) under stirring at a speed in the range of 3500 to 4000 rpm to obtain an emulsion matrix having negative oxygen balance;
(d) adding to the said emulsion matrix obtained in step (c), oxidizer salt in particle form, such as ammonium nitrate prill, to obtain an emulsion matrix with near zero oxygen balance;
(e) adding to the resultant emulsion matrix obtained in step (d), gassing agent such as a 1:1 mixture of sodium nitrite and zinc nitrate in aqueous solution of mixture : water of ratio 1:4.

13. A process for making emulsion explosive as claimed in claim 12, wherein the pH of the oxidizer solution is maintained in the range 4.00 to 4.50 by adding acid/base such as sulphamic acid, nitric acid, sodium bicarbonate.
14. A process for making emulsion explosive as claimed in claim 12-13, wherein the oxidizing solution is added to the fuel phase at a temperature of around 60 to 62 °C.
15. A process for making emulsion explosive as claimed in claim 12-14, wherein the oxidizer salt in particle form, such as ammonium nitrate prill, is added to the emulsion matrix at a temperature of around 45 to 50 C.
16. A process for making emulsion explosive as claimed in claim 12-15, wherein 7 to 8 ml of the gassing agents solution is added per kilogram of the product to achieve detonation density in the range 1.05 to 1.20g/cm at around 40-45 C.
21. A synergistic composition of emulsion explosive useful for blasting in surface mines, and a process for making emulsion explosive substantially as herein described with reference to the examples.

Documents:

966-DEL-2002-Abstract-(03-11-2008).pdf

966-del-2002-abstract.pdf

966-DEL-2002-Claims-(03-11-2008).pdf

966-del-2002-claims.pdf

966-DEL-2002-Correspondence-Others-(03-11-2008).pdf

966-del-2002-correspondence-others.pdf

966-del-2002-correspondence-po.pdf

966-DEL-2002-Description (Complete)-(03-11-2008).pdf

966-del-2002-description (complete).pdf

966-DEL-2002-Form-1-(03-11-2008).pdf

966-del-2002-form-1.pdf

966-del-2002-form-18.pdf

966-DEL-2002-Form-2-(03-11-2008).pdf

966-del-2002-form-2.pdf

966-DEL-2002-Form-3-(03-11-2008).pdf

966-del-2002-form-3.pdf

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Patent Number

226274

Indian Patent Application Number

966/DEL/2002

PG Journal Number

01/2009

Publication Date

02-Jan-2009

Grant Date

16-Dec-2008

Date of Filing

24-Sep-2002

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	BRAJ MOHAN PAT PINGUA	CENTRAL MINING RESEARCH INSTITUTE ,BARWA ROAD,DHANBAD-826 001,JHARKHAND,INDIA
2	NABIULLAH	CENTRAL MINING RESEARCH INSTITUTE,BARWA ROAD, DHANBAD-826 001,JHARKHAND,INDIA
3	JAGDISH	CENTRAL MINING RESEARCH INSTITUTE ,BARWA ROAD, DHANBAD-826 001,JHARKHAND,INDIA

PCT International Classification Number

C06B 45/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA