Field of the Invention
The present invention relates to water in oil emulsion explosives used for
industrial purposes, of such consistency that they can be paper wrapped. More
particularly the present invention relates to congealed water in oil emulsion
explosives of small diameter having improved viscosities above at least 2 million
cps
The present invention further relates to a process of preparing the water in oil
emulsion explosives of the present invention and process of packing them in
paper cartridges
The area of application of these industrial explosives includes general-purpose
mining of all kinds for example excavation, tunneling, quarrying, well sinking in
above ground usage and in tunneling as well as coal mining in underground
usage
Background of invention
Industrial explosive is a powerful and cheap energy resource widely used in agriculture, water conservancy, transportation, mining, building material and so
on
A brief review of the development of industrial explosives and initiation system in
India shows the progress from use of gunpowder as industrial explosives to the
use of emulsion explosives.
Gun Powder
Gunpowder, a mixture of Potassium Nitrate, sulphur and charcoal was
undoubtedly the first explosive recorded in Chinese manuscript
NG Based Explosives (Dynamite)
First revolution in Industrial Explosives came in mid 19th century with discovery to
Nitro Glycerin by Sobrero in 1845 and Nitrocellulose by Schoeinbien in 1846 and
finally of dynamite by Alfred Nobel in 1860's by using Kieselguhr as absorbent
Slurries & Water gel
Combination of ammonium nitrate and sensitizer lead to formation of slurries as
the new generation of explosives Finally after lot of experiments with the use of
flake aluminium as sensitizer, atomized aluminium as source of energy and some
gelling agents and stabilizing agents a new series of slurry products were
developed However, the slurnes/watergels had some limitations when used as
small diameter explosives particularly for under ground coal operations Similarly
for non-coal and construction operations, the small diameter slurry products
could not have higher density or higher VOD to give effective blast performance
Emulsion Explosives
Between 1980's and 1990's emulsion explosives came up The basic principle
was to shear an aqueous based oxidizer solution to oil based liquid fuel mix to
micro size droplets Each micro fine droplet contains oxidizer with proportionate
amount of fuel Without addition of a sensitizer an initiator would start initiation in the product
Emulsion explosives are the latest generation of explosives and are rapidly establishing themselves in the market because of their wide range of favorable excellent properties Emulsion explosives do not contain toxic ingredients, they are stable during storage and do not freeze Due to their water content, they are relatively insensitive to impact, flame or friction, their oxygen balance is positive, so they are also suitable for underground blasting, where methane or coal dust are present
Emulsion explosives are emulsions of fine droplets of oxidant solutions, which are separated by an extremely thin membrane from oils, waxes and paraffins that serve as fuel The contact between the two phases is so close that chemical reaction between them is explosive provided the density of the explosive is sufficiently low.
It has been especially known that the water in oil type emulsion explosives exhibit high detonating velocity, which cannot be attained in conventional slurry explosives and are extremely safe as compared with dynamites
Some such explosives are disclosed in the patent literature
US 4,141,767 discloses emulsified aqueous explosive blasting compositions having a discontinuous aqueous phase, a continuous oil or water-immiscible
liquid organic phase, and a fatty acid amine or ammonium salt emulsifier having a chain length ranging from 14 to 22 carbon atoms
US 4,322,258 discloses thermally stable, cap-sensitive water-in-oil emulsion explosive composition having a discontinuous aqueous oxidizer salt solution phase containing calcium nitrate, a continuous oil or water-immiscible liquid organic phase, an emulsifier, and a density reducing agent
US 4,357,184 describes a water-in-oil explosive composition based on colloidal dispersions The micro emulsion composition of the invention is said to displays exceptional long-term storage stability retaining sensitivity to propagation even in small diameter charges The micro emulsion-producing component of the composition comprises a combination of at least one conventional water-in-oil emulsifier and at least one amphiphatic synthetic polymeric emulsifier selected from graft, block or branch polymers
US 4,822,433 discloses an emulsion explosive composition comprising a discontinuous phase containing an oxygen-supplying component and an organic medium forming a continuous phase wherein the oxygen-supplying component and organic medium are capable of forming an emulsion which, in the absence of a supplementary adjuvant, exhibits an electrical conductivity measured at 60 degree C , not exceeding 60,000 picomhos/meter Such conductivity may be
achieved by inclusion of a modifier These compositions are said to exhibit improved storage characteristics
US 4,708,753 discloses a water-in-oil emulsion which comprises a continuous oil phase, a discontinuous aqueous phase; a minor emulsifying amount of at least one salt derived from (i) at least one hydrocarbyi-substituted carboxylic acid or anhydride, or ester or amide derivative of said acid or anhydride, the hydrocarbyl substituent of (i) having an average of from about 20 to about 500 carbon atoms, and (II) at least one amine, and a functional amount of at least one water-soluble, oil-insoluble functional additive dissolved in said aqueous phase The emulsion explosives so obtained are of pasty or greasy consistency
The emulsion type explosives of a pasty or greasy consistency can be filled by
extrusion into polyethylene tube or wrapped in poly film with mechanical sealing
with metal clips on either side of cartridge
The conventional packing machines are therefore based on the principle of
extrusion of the pasty mass through a nozzle tube and then wrapping and sealing
it in a poly film However this is not a preferred pack owing to the product
characteristics of the conventional emulsion explosives and poly film cartridge
problems
The conventional process of manufacturing small diameter emulsion explosives
has main draw back of product viscosity limit owing to necessity of rotopump line
transfer and on line gassing Vagaries of weather affect the product quality and
performance reliability including shelf life Slow shear stress during transit also
alters the rheology of the emulsion matrix
When such products are packed in polyethylene tube or wrapped in poly film,
additional problems are faced The poly film cartridges can become limp and
curved causing difficulty in charging straight driven shot holes
Above all the metal clip has to be of expensive copper wire for safety in
underground mining applications, which increases the costs of packaging
Moreover the risk of incendivity or deflagration caused by hot metal-be it copper
or aluminium cannot be ruled out, particularly with the emulsion, which have to
show Velocity of Detonation (VOD) higher than the old dynamites for purpose of
matching strength
Hence it is preferable to pack emulsion explosives in safe and non-hazardous
paper cartridges
Although emulsion explosives are relatively plastic in comparison with slurry
explosives, attempts to packaging them into paper cartridge are relatively
unsuccessful since they are softer as compared with dynamite, which have been
also used as paper cartridges Packing the softer emulsion explosives in paper
cartridge can result in deformation upon transportation and handling of paper
cartridges and deformed paper cartridges of the water in oil type emulsion
explosive can not easily be charged into charging holes and thus are not
convenient for use
Attempts to increase the thickness of cartridge paper to improve the strength of
the cartridge increases the packaging costs and is hence not preferred
Addition of additives in powder form to increase the hardness of emulsion explosives results in problems like degradation in the stability of the emulsion explosives and significant reduction in the blasting performance. Thus there is a long felt need to have emulsion explosives of high viscosity, which have improved stability and can be effectively packed in paper cartridges thus reducing the overall cost of manufacturing and providing a safe non-hazardous paper packing without use of expensive raw materials The present inventors have surprisingly found that water in oil emulsion explosives when formulated using a combination of microcrystalline wax and sorbitan sesquioleate result in high viscosity emulsions that are not only more stable and have higher velocity of detonation than conventional emulsion explosives but have a thick near solid consistency enabling them to be packed in paper cartridges with ease
These explosives can be conveniently be utilized for industrial blasting operations such as in excavating tunnels, quarrying and mining They are highly safe and are less hazardous compared with previous conventional explosives
Objects of the invention
It is thus an object of the present invention to provide water in oil micro emulsion compositions for industrial explosives that overcome the problems associated with prior art
It is further object of the present invention to provide water in oil micro emulsion
compositions for industrial explosives that are simple to manufacture and cost
effective
It is further object of the present invention to provide water in oil micro emulsion
compositions for industrial explosives that have near solid consistency
Yet another object of the present invention is to provide water in oil micro
emulsion compositions for industrial explosives that have viscosity of at least 2
million cps
Yet another object of the present invention is to provide water in oil micro
emulsion compositions for industrial explosives that essentially combine
microcrystalline wax and sorbitan sesquioleate to surprisingly achieve extremely
high viscosity of at least 2 million cps
Yet another object of the present invention is to provide water in oil micro
emulsion compositions for industrial explosives that can be easily paper wrapped
in paper cartridges thus further making them cost-effective, safe and eco-fnendly
Another object of the present invention is to provide water in oil emulsion
compositions for industrial explosives that have higher velocity of detonation and
therefore more efficiency
Another object of the present invention is to provide water in oil micro emulsion
compositions for industrial explosives that are stable on storage
Yet another object of the present invention is to provide a process for making
water in oil micro emulsion compositions for industrial explosives that is simple
and eco-fnendly
Yet another object of the present invention is to provide a process for packing the water in oil micro emulsion compositions in paper cartridges
Summary of invention:
Thus according to an aspect of the present invention, there is provided a water in
oil micro emulsion composition for industrial explosives comprising essentially of
a combination of microcrystalline wax and sorbitan sesquioleate
According to the preferred aspect of the present invention, the compositions
comprise of one or more oxidizers in the aqueous phase, one or more fuels,
sorbitan sesquioleate and inert sensitizers, wherein one of the fuels is essentially
microcrystalline wax
The viscosity of the emulsions of the present compositions is at least 2 million
cps
According to a second aspect of the present invention, there is provided a
process of making the water in oil micro emulsion compositions comprising steps
of
i) preparing oxidizer solution in the aqueous phase,
II) preparing the fuel and emulsifier blend as the oil phase,
III) mixing the aqueous and oil phase with continuous agitation,
IV) cooling the emulsified mixture to obtain a near solid consistency
The explosives so obtained are then packed in paper cartridges
According to a third aspect of the present invention, there is provided a process
for packing the water in oil micro emulsion compositions in paper cartridges
comprising steps of
i) preparing the emulsion explosive compositions as per the process of the
invention,
II) cooling the compositions to an optimum temperature of 15 to 20 deg C
III) cartridgmg the solid compositions obtained in step (ii) using a paper
cartridgmg machine comprising steps of
- machine cutting the slab to preset width and thickness,
- pushing the sized emulsion explosive pieces onto the paper source,
- wrapping the sized emulsion explosive pieces in the cartridgmg paper,
- crimping the packed emulsion explosives
Detailed description
An emulsion explosive is a mixture of two immiscible liquids, which are intimately dispersed by using proper agitation and make the stability of the intimate mixture through the use of proper emulsifier or a mixture of emulsifier and surfactant The emulsion explosive of the present invention is a water-in-oil emulsion Each droplet of oxidizer is intimately coated with the fuel phase containing oil, wax and emulsifier The refinements of droplets depend upon agitation or shearing created during manufacturing and selection of suitable emulsifier To start with HLB is the criteria to select proper emulsifier However, finally selection depends
on the actual trial and error on the basis of other constituents present in the
composition Emulsifier is responsible for not only to refinement but also for
stability of emulsion, in turn shelf life of emulsion explosive and excellent
performance qualities
Sensitization is primarily due to intimate contact of micro fine oxidizer globules
and fuel film and density control which is enhanced by chemical gassing or by
expanded perlite or glass micro balloon or polystyrene / plastic micro spheres
depending on requirement in the product
It has been said that emulsion explosives show inferior performance and poor
blasting power compared with dynamite The present invention has improved the
performance of emulsion explosives and has developed new explosive
technology with a superior performance as well as high safety and easy
packaging in paper cartridges
Paper wrapped emulsion explosives are more eco-friendly than poly film wraps
as the waxed paper acts as carbonaceous fuel in the detonation reaction than
the poly film, which throws out non-biodegradable waste, highly unwelcome in
the current global scenario
Small diameter industrial blasting explosives of packaged type are available in
the form of poly wrapped cartridges of identical sizes, ready for use with
conventional priming using No 6/8 detonator
The present invention involves industrial explosives of paper wrapped emulsion
type in of cartridges 25-50 mm diameter These can be conveniently used in all
industrial applications like all kinds of mining including surface as well as
underground blasting of coal and minerals. They can also be used in tunneling,
quarrying, well sinking and so on
Conventionally water in oil emulsion explosives comprise essentially of oxidizers,
fuels and emulsifiers
According to the preferred aspect of the present invention, the compositions
comprise of one or more oxidizers in the aqueous phase, one or more fuels,
sorbitan sesquioleate and microspheres wherein one of the fuels is essentially
microcrystalline wax
The viscosity of the emulsion explosive compositions of the present is at least
from 2 million cps to 5 million cps
Aqueous phase
The aqueous phase is the discontinuous phase in the present invention and is present in a quantity of 5 to 15% and preferably from 8 to 11% by weight of the total composition
Oxidizers
The oxidizers used in the present invention are present in the aqueous phase of the compositions They are the oxygen-supplying components of the explosive compositions and comprise of any oxidizer salt capable of releasing oxygen in an

explosive environment in an amount and at a rate sufficient to confer acceptable explosive characteristics on the emulsion composition Inorganic oxidizer salts conventionally employed in the production of emulsion explosive compositions,
and suitable for inclusion in the compositions of the present invention include
ammonium salts and salts of the alkali- and alkaline-earth metals, such as the
nitrate, chlorate and perchlorate salts, and mixtures thereof
Preferably the oxygen-supplying component is selected from the group
consisting of ammonium nitrate, sodium nitrate, calcium nitrate, sodium
perchlorate and mixtures thereof
Ammonium nitrate is preferably employed as a primary oxidizer salt comprising
at least 50%-90% by weight of the oxygen-supplying salt component,
supplemented, if desired, by a minor (not exceeding 10% by weight) amount of a
secondary oxygen-supplying component, such as sodium perchlorate or sodium
nitrate
Typically, the oxygen-supplying component of the composition of the present
invention comprises from 65 to 85 % and preferably from 75 to 80 % by weight of
the total composition
Fuels
Suitable water-immiscible emulsifiable fuels for use in the water-in-oil emulsion include most hydrocarbons, for example, paraffinic, olefinic, naphthenic, elastomenc, aromatic, saturated or unsaturated hydrocarbons Preferred among the water-immiscible emulsifiable fuels are the highly refined paraffinic hydrocarbons Suitable organic-fuel media, which are capable of existing in the liquid state at convenient emulsion formulation temperatures, preferably include mineral oil, diesel oil, paraffin oil, petroleum distillates and mixtures thereof
The present compositions comprise of one or more fuel media and essentially
comprise at least one liquefiable carbonaceous fuel source like wax preferably
microcrystalline wax
The quantity of microcrystalline wax used for the present invention is 1-6% and
preferably 2-4 % by weight of the total composition
The quantity of liquid or liquefiable carbonaceous fuel used in the water-in-oil
micro emulsion may comprise up to 1-6% and preferably 2-4 % by weight of the
total composition
Emulsifier
The emulsifier employed for the present invention is sorbitan sesquioleate It is
surprisingly found that this emulsifier in combination with microcrystalline wax
results in high viscosity emulsions that can be easily roll-packed in paper
cartridges conventionally applied only for solid dynamite packing
The quantity of emulsifier used in the water-in-oil micro emulsions of the present
invention may comprise from 1 to 4% preferably from 2 to 4% by weight of the
total composition
Sensitizer
Void-containing material is incorporated in emulsion explosives to sensitize the emulsions and render them more easily detonable Typically, void-containing material to be incorporated into the compositions of the present invention is in the form of fine gas bubbles dispersed throughout the water-in-oil emulsion
component of the explosive composition, hollow particles, porous particles or
combinations thereof
Fine gas bubbles may be dispersed throughout the water-in-oil emulsion
component by any convenient means such as by mechanical agitation, injection
or bubbling gas through the composition, or by in situ generation of the gas by
chemical means
Suitable chemicals for the in situ generation of gas bubbles include peroxides,
nitrites, nitrosoamines, alkali metal borohydrides and carbonates
Examples of suitable hollow particles include small hollow microspheres of glass
Examples of suitable porous materials include expanded minerals incorporating
air such as perlite
The preferred sensitizer for the purpose of the present invention is expanded
mineral such as perlite, commercially available as Q-cells
The quantity of sensitizer used in the water-in-oil micro emulsions of the present
invention may comprise from 2-5% preferably from 2-3% by weight of the total
composition.
Dopant
Dopants are additives in the form of powder or prills of various substances like Ammonium Nitrate, Aluminium powder or common salt These are added to modify the power as well as incendivity characteristics of the emulsion products The quantity of dopants used in the water-in-oil micro emulsion may comprise up 5 to 50% and preferably 10 to 40% by weight of the total composition
The compositions of the present invention so obtained can be then packed in a
suitable paper such as Kraft paper preferably coated with paraffin wax to
incorporate water resistance
The compositions of the present invention thus facilitate low temperature packing
with enhanced safety & thermal stability unlike the high temperature packing of
conventional emulsion explosives
The process for preparing the micro emulsion explosives of the present invention
comprise steps of
(i) preparing oxidizer solution in the aqueous phase;
(ii) preparing the fuel and emulsifier blend as the oil phase,
(iii) mixing the aqueous and oil phase with continuous agitation;
(iv) cooling the emulsified mixture to obtain a near solid consistency
The explosives so obtained are then packed in paper cartridges.
The process is explained hereunder in greater details in respect to the preferred aspects and conditions not to be construed as for limiting the scope of the invention but for better understanding of the invention Preparation of Oxidizer Solution
The oxidizer salts are weighed in appropriate proportion and dissolved in measured quantity of water in a Stainless Steel tank fitted with agitator, at temperature in the range to 60 to 90°C The fudge point and specific gravity of the solution are checked Preparation of Fuel/ Emulsifier blend
The fuel-emulsifier phase is also blended at prescribed temperature 60 to 80°C
Mixing
The mixing stage can be preferably carried out in a ribbon blender preferably pre-
warmed
The fuel emulsifier blend is taken initially in the ribbon blender kept warm (60 to
90°C) The oxidizer solution is gradually added with continuous agitation at 80-
150 rpm for about 15 minutes The viscosity of the emulsion matrix is checked
using Brookfield Viscometer in order to verify and confirm the adequacy of
emulsification process
In case a dopant material is added, the agitator speed is then adjusted to a safe
lower level of 10 to 30 RPM during incorporation of the dopant material and
mixing is carried out for about 2 to 10 minutes
Finally the weighed quantum of sensitizer is added and mixed for one minute
The product mass is then unloaded into a hopper wherefrom it is filled in
aluminium trays of suitable size
Cooling
In order to achieve the cartridgeable consistency the present inventors have
found it essential to cool down the dough to an optimum temperature of 15 to
20°C by controlled feed using a conveyor through cold-water bath at 5°C and
then through a cool air duct
The explosives so obtained are then packed in paper cartridges
Cartridqinq and Packing
The material in the form of a long slab of given width and thickness is cartndged
and roll packed using paper cartridging machines such as Rollex machine
The process for packing the water in oil micro emulsion compositions in paper
cartridges comprises steps of
i) preparing the emulsion explosive compositions as per the process of the
invention,
II) cooling the compositions to an optimum temperature of 15 to 20 deg C
iii) cartridging the solid compositions obtained in step (ii) using a paper
cartridging machine comprising steps of
machine cutting the slab to preset width and thickness, pushing the sized emulsion explosive pieces onto the paper source, wrapping the sized emulsion explosive pieces in the cartridging paper, crimping the packed emulsion explosives
The material in the form of a long slab of giving width and thickness is cartndged by knife, pusher, revolver and crimper mechanism The process comprises of a number of operations involving cutting with the knife, pushing on to the paper, stripping from cylindrical cartridge using revolver
Effective cooling of the Emulsion product is essential for efficient packing in the paper cartridges In order to achieve the cartridgeable consistency, the inventors have found it essential to cool down the dough to an optimum temperature of 15 to 20 deg C by controlled feed through conveyor through cold water at 5 deg C and cool air duct, depending on the ambient atmospheric conditions
The machine used for paper cartndging is any conventional machine especially
the Rollex machine Certain modifications adjustments are necessary for
adopting the standard Rollex machine for emulsion product cartndging
The Rollex machine has the original design meant for gelatinous semi gelatinous
consistency of material, certainly not for a pasty or sticky product like high
viscosity emulsion
The additional modification / alterations introduced by the inventor include
a) Air jet connection to either side of the pusher.
b) Automatic sprinkling / spray of compatible powder over the bed of the material evenly so as to prevent stickiness resulting in retraction of the sliced cake of material with the pusher prior to wrapping and crimping
Continuous process of mixing with automatic programmed weighing and dosing of ingredients, thermostatically controlled cooling water, air-cooling system for efficient cartndging and moisture elimination by air blowing are some of the modifications known to persons skilled in art that can be carried out to improve the process performance and are thus covered by the scope of the invention
The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to the non-limiting exemplary illustrations
EXAMPLES
General Manufacturing process
Preparation of Oxidizer Solution All oxidizing salts including nitrates and perchlorates are accurately weighed in desired proportion and dissolved in measured quantity of water in a SS tank under agitation, maintaining temperature of solution in the range of 60 to 90°C Fudge point and specific gravity of the solution are checked to confirm to specific values
Preparation of Fuel Blend The fuel consisting of various waxes including microcrystalline wax and emulsifier consisting of sorbitan sesquioleate are blended at a temperature of 60 to 80°C to a homogenous mix 3 Mixing and Emulsification
Fuel emulsifier blend is transferred to Patterson mixer and maintained at a temperature of 60 to 90°C Starting the blender agitator, oxidizer solution is added gradually over a fixed period of time allowing formation of water -in-oil emulsion. After achieving the desired emulsion consistency & viscosity, various dopants like Ammonium nitrates prills, atomized aluminium powder etc are added at slow blending rate Finally the required quantity of sensitizer is added and slowly blended into the emulsion mass Finally the ready emulsion is pumped for cooling and cartridging
EXAMPLE 1:
To study the effect of different emulsifiers on the viscosity of the product (without
sensitizers):
Emulsion was prepared using the general method of manufacture as mentioned
above
To generate viscosity data all the process parameters were maintained constant
Composition of oxidizer solution was also maintained constant
In Fuel blend, Fuel-emulsifier ratio was maintained at 1 1 whereas in emulsion
matrix, oxidizer solution - fuel blend ratio was maintained at 94 6
Sensitizer (Q-cells) were not added purpose being to demonstrate effect on
viscosity of emulsifier and wax combinations.
The following compositions were made using the process of the invention
Keeping all other ingredients constant, only the emulsifier was changed to study
the effect of different emulsifiers on the viscosity of the product The viscosity
was measured using Brookfield viscometer using Spindle No 7 at 0 5 rpm for
viscosity measurement
In this example, following emulsifiers were tried out
SSQ sorbitan sesquioleate
SMO Sorbitan mono oleate
DG6 and NBX 2000 are polymeric emulsifiers based on poly iso butylene
succinic anhydride (PIBSA)
(Table Removed)
The viscosity results are tabulated in Table 1 as under
Table 1: Effect of synergistic combination of sorbitan sesquioleate and
microcrystalline cellulose on emulsion viscosity without addition of sensitizers:

(Table Removed)
It is thus evident from the above table that the synergistic combination of sorbitan sesquioleate and microcrystalline wax increases the viscosity of the emulsion explosive dramatically vis-a-vis the other emulsifier and wax combinations thus demonstrating the inventive selection of the said ingredients
EXAMPLE 2:
To study the effect of different emulsifiers on the viscosity of the product (with
sensitizers):
To the compositions 1-4 same quantity of sensitizer, Q-cells was added (3 parts
of Q-cell to 100 parts of emulsion matrix), to see the synergy between emulsifier
and the sensitizer
The viscosity was measured using Brookfield viscometer using Spindle No 7 at
0 5 rpm for viscosity measurement
The viscosity results are tabulated in Table 2 as under
Table 2: Effect of synergistic combination of different emulsifiers and
sensitizer on emulsion viscosity:

(Table Removed)
It is thus evident from the above table that the synergistic combination of sorbitan sesquioleate and microcrystalline wax with addition of sensitizer Q-cells increases the viscosity of the emulsion matrix dramatically vis-a-vis the other emulsifier and wax combinations similarly treated, thus demonstrating the inventive selection of the said ingredients
EXAMPLE 3:
Comparison of velocity of detonation of high viscosity emulsion as per present invention with explosive products manufactured as per prior art technologies
Velocity of detonation determined by Dautriche Method (Reference IS 6609-Part 4,1984), is a measure of the power of explosive Vide Table -3, we are presented the velocity of detonation of emulsion explosives manufactured as per present invention as well as as per prior art technologies
Prior art technologies consists of nitroglycerin based dynamites, which do not require sensitizer; water gel slurries, which are sensitized, using air bubbles; prior art low viscosity (less than 1 0 million cps) emulsions sensitized with Q-cells
The results are as tabulated in Table 3 hereunder
Table 3:
Velocity of detonation of emulsion explosives manufactured as per present invention and as per prior art technologies:

(Table Removed)
It is evident from the above table that the velocity of detonation is higher for high viscosity emulsions formulated as per present invention as compared to the conventional low viscosity emulsions of prior art; thus improving the blasting efficiency of the explosives
Beside, the emulsion explosives of the present invention give superior results vis-a-vis earlier generation water gel slurry & dynamite explosives as well thus further increasing the possibility of total replacement of hazardous and unsafe dynamite explosives with safe, effective and easy to manufacture emulsion explosives of the present invention.

WE CLAIM
1. Water in oil micro emulsion composition for industrial explosives comprising
essentially of a combination of microcrystalline wax as a fuel source and sorbitan
sesquioleate as emulsifier wherein microcrystalline wax is 1-6% by weight of total
composition and sorbitan sesquioleate is 1 to 4% by weight of total composition and
oxidizer salt from 65 to 85% by weight of total composition.
2. A composition as claimed in claim 1 further comprises of
(a) one or more oxidizer salts in the aqueous phase
(b) one or more fuels
(c) and one or more sensitizers
wherein one of the fuels is essentially microcrystalline wax.
3. A composition as claimed in claim 1 wherein the oxidizer salts include ammonium salts and salts of the alkali- and alkaline-earth metals, such as the nitrates, chlorate and perchlorate salts, and mixtures thereof.
4. A composition as claimed in claim 3 wherein the oxidizer salt is selected from the group consisting of ammonium nitrate, sodium nitrate, calcium nitrate, sodium perchlorate and mixtures thereof.

5. A composition as claimed in 4 wherein the oxidizer salt is ammonium nitrate.
6. A composition as claimed in anyone of claims 1 to 5 wherein the oxidizer salt is preferably from 75 to 80% by weight of the total composition.
7. A composition as claimed in claim 2 wherein one or more fuels are selected from liquid or liquefiable hydrocarbons including paraffinic, olefinic, naphthenic. Elastomeric, aeromatic, saturated or unsaturated hydrocarbons.
8. A composition as claimed in claim 7 wherein one or more fuels preferably include mineral oil, diesel oil, paraffin oil, petroleum distillates and mixtures thereof and at least one liquefiable hydrocarbon.
9. A composition as claimed in claims 1, 7 and 8 wherein one or more fuels is essentially liquefiable hydrocarbon like microcrystalline wax.
10. A composition as claimed in claim 9 wherein microcrystalline wax is preferably 2-4% by weight of the total composition.
11. A composition as claimed in claim 9 wherein microcrystalline wax is 1-6% and preferably 2-4% by weight of the total composition.
12. A composition as claimed in claim 1 wherein sorbitan sesquioleate is preferably from 2 to 4% by weight of the total composition.

13. A composition as claimed in claim 2 wherein the sensitizers are void-containing material present in the form of fine gas bubbles dispersed throughout the emulsion, hollow particles, porous particles or combinations thereof.
14. A composition as claimed in claim 13 wherein the sensitizers are porous materials including expanded minerals incorporating air such as perlite.
15. A composition as claimed in claim 13 wherein the sensitizers are added from 2-5% preferably from 2-3% by weight of the total composition.
16. A composition as claimed in claim 2 wherein the aqueous phase is the discontinuous phase present from 5 to 15% and preferably from 8 to 11% by weight of the total composition.
17. A composition as claimed in claims 1 or 2 wherein it optionally comprises of one or more dopants.
18. A composition as claimed in claim 17 wherein the dopant is prilled ammonium nitrate or aluminium powder or mixtures thereof.
19. A composition as claimed in claim 18 wherein one or more dopants are present from 5 to 50% and preferably from 10 to 40% by weight of the total composition.
20. A composition as claimed in claims 1-19 wherein the viscosity of the emulsion explosives is at least 2 to 5 million cps.
21. A composition as claimed in claims 1-20 wherein the near solid emulsion so obtained is packed in paper cartridges.
22. A process for preparing water in oil micro emulsion composition as claimed in claim 1 comprising steps of:
preparing oxidizer solution in the aqueous phase;
preparing the microcrystalline wax and sorbitan sesquioleate blend as the oil phase;
mixing the aqueous and oil phase with continuous agitation;
cooling the emulsified mixture to obtain a near solid consistency.
23. A process as claimed in claim 20 wherein the emulsion is cooled to at least 15 to
20°C to obtain a near solid consistency.
24. A process for packing the water in oil micro emulsion compositions in paper
cartridges comprising steps of
i) preparing the emulsion explosive compositions as claimed in claim 1,
ii) cooling the compositions to an optimum temperature of 15 to 20 deg. C
iii) cartridging the solid compositions obtained in step (ii) using a paper cartridging machine comprising steps of machine cutting the slab to preset width and thickness, pushing the sized emulsion explosive pieces onto the paper source, wrapping the sized emulsion explosive pieces in the cartridging paper, crimping the packed emulsion explosives.
25. A composition as substantially described herein and illustrated in reference to the
accompanying examples.