AU598130B2

AU598130B2 - Explosive compositions

Info

Publication number: AU598130B2
Application number: AU16925/88A
Authority: AU
Inventors: Kevin Hunter Waldock; Daniel Aaron Wasson
Original assignee: CBS Explosives Pty Ltd
Current assignee: Dyno Nobel Asia Pacific Pty Ltd
Priority date: 1987-06-10
Filing date: 1987-06-10
Publication date: 1990-06-14
Anticipated expiration: 2008-05-23
Also published as: AU1692588A

Description

598130 COMMONWEALTHI OF AUSTRALIA Patents Act 1952

COMPLETE

SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number Lodged Complete Specification Lodged Accepted Published This document contains the amendments made under Section 49 and is cirrect for printing.

Priority Related Art Name o. Applicant Address of Applicant Actual Inventors Address for Service CBS EXPLOSIVES PTY. LTD.

Woodlands itoad, Mount Thorley, New South Wales, ')330, Commonwealth of Australia Daniel Aaron Wasson and kevin hunter Waldoci IH.R. IIOUDGKINSON CO.

Patent Trade Mar Attorneys 26A Alired Street MILSUOS POINT NSW 2061 EXPLO8IVE COMPOSIYTIOiS CompLete Specification for the Invention entitled: The following statement is a full description of this invention including the best method of performing it known to us:i: r -i t BACKGROUND TO THE PRESENT INVENTION THIS INVENTION relates to explosive compositions, and in particular to a dry mix explosive composition.

Explosives, including dry mix explosives, have been known for a number of years anO have been relatively widely used. Sucn dry mix explosive compositions alre all elssentially different mixes of oxidizer and fuel.

In various formulations developed over the years, the oxidizer portion of the composition was essentially amfooniumnitrate and the -reafter other nitrate sal\vs were added. Fuels such as a fuel sensitizer was often used and additional liquids such as othee grade of fuel oil, alcohols, paraffin and nitrated paraffins have been added. Tn addition, other additives such as molecular explosives (for example TNT or smokeless powder) were also added. Combinations of different powdered fuels have been used to replace liquid fuels.

Essentially however all the mixes have been relatively similar in that they are compcosite explosives being mixtures of oxidizer and fuel.

It is an object of this invention to provide an improved and efficient explosive composition.

Other objects of this invention wilt become apparent from the following description.

SUMMARY OF THE PRESENT INVENTION According to one aspect of this invention there is provided a dry mixc explosive composition, including a bulking agent, comprising from 1 20% (by weight) of a fibrous vegetable protein additive; said bulking agent having a bulk density of fronk 0.1 0J.6 grams per cubic centimetre and said explosive composition having a bulk density of from 0.5 1.1 grams pez cubic- centinrebrto.

i DETAILED DESCRIPTION OF THE INVENTION This invention will now be described by way of example only and it should be appreciated that modifications and improvements may be made to the invention without departing from the scope thereof, as defined by the claims appended hereto.

The present invention sets out to provide an improved and effective low density dry mix explosive composition.

It has been found that the explosive composition of the present invention, essentially utilizing a bulking .'ent which comprises vegetable protein matter, provides an improved and efficient explosive composition with a lower density.

Use of the explosive composition of the present invention, utilizing the bulking agent, has shown that rock breakage on an equal weight basis is advantageous.

3 It tas been found in particular that tie explosive composition of the present invention allows for the parts thereof to ii be more evenly and regularly distribru.: d over the area or |i length of the explosive charge. For example, if a miner is i 5 inserting explosive into a blast hole, then using known explosive compositions, the active parts of the composition s are likely in many cases to be localised (such as for example towards the bottom of the blast hole). This then means that 1 ion detonation, there may oe a relatively localised explosion I 10 in one particular area x the blast hole, rather than substantially along the length or area of the blast hole (which is more effective and advantageous). By using the explosive composition of the present invention, incorporating a bulking agent comprising vegetable protein matter, the parts of the composition are found to be more evenly distributed throughout the length or area of the composition and the blast hole (or area to be blasted), as a result of which there is a more equal distribution of detonation force.

It has been further found that by using fibrous vegetable protein matter, in the bulking agent of the present invention, the fibrous natue of such vegetable matter i, assists in holding together the component parts of the compositions and contributes towards resisting segregation, i| such as may be caused by wind, external forces, or during i 25 loading of blast holes and the like.

In a preferred form of the invention, the explosive composition includes appropriate known or suitable ,1 oxidizer(s) and fuel(s), and also includes a bulking agent which is formed comprising from 1 to 20% (by weight) vegetable protein additive, the bulking agent having a bulk density of from 0.1 to 0.6 grams per cubic centimeter.

In a further form of the invention, the bulking agent comprises from 0.5 to 100 (by weight) lipids.

In a preferred form of the invention, the bulking agent includes up to 5% (by.weight) vegetable protein content, tle bulking agent having a bulk density of 0.2 grams per cubic centimeter.

By way of example only, we set out below various forms of the K dry mix explosive composition according to the pr'zent invention, the various parts being stated by weight: Dry oxidizer salts, a carbonaceous liquid fuel and a finely divided protein containing bulking agent as the j0 active constituents.

The constituents as set out in above in the ratios if which will preclue detonation with a number 8 detonating cap.

The constituents as set out in above wherein the dry oxidizer salt. comprise ammonium nitrate and other inorganic nitrate salts.

The constituents as set out in above wherein the carbonaceous fuel contains fuel oil grade 2 distillate).

The constituents as set out in above wherein the dry oxidizer salts include ammonium perchlorate.

The constituents as set out in above wherein the finely divided protein containing bulking agent additive contains from 1 to 20% vegetable protein, 0.5 to lipids and has a bulk density of 0.1 to 0.6 grams per cubic centimeter.

i i The constituents as set out in above wherein the dry oxidizer is ammonium nitrate and including a fuel sensitizer which is a mixture of powdered fuels and metals.

The constituents as set out in above wherein the dry oxidizer is ammonium nitrate porous prills, the fuel is grade 2 distillate, and the bulking agent is a chopped material conta ining vegetable protein.

Further, and by way of example only, several representative and preferred formulations of the present invention are now given and set out below, the percentages again being stated by weight; Formulation numbers:- Constituents: Ammonium Nitrate Calcium Nitrate Sodium Nitrate Molecular explosive Distillate grade 2 75 70 57 10 84 89 uiking Agent 10 10 It should be noted that the preferred bulk densities of the mixtures referred to in the above formulations are, by way of example, from 0.5 to 1.1 grams per cubic centimeter.

It snould be appreciated tnat any appropriate molecular explosive may be used, such as for example TNT relleto; smokeless powder, methyl amine nitrates; ethanol amine nitrate and and the like. Further, it should be appreciated that in some forms of the invention, the molecular explosive may be provided in a slurry form, such as mixed wit.' a solvent, such as water. In one form of the invention, a molecular explosive, such as methyl amine nitrate, may be mixed with water up to about 10% (by weight) to form an explosive slurry.

In a further form of the present invention, a further additive is used in order to prevent or decrease segregation.

It is always a problem with dry explosive compositions, that parts of the composition may separate, or be blown Away during mixing, or in particular during loading into a blast hole. In particular, during loading into a blast hole, the parts of the composition may become segregated, the heavier parts reaching the bottom of the blast hole first. This segregation can result in irregular blasting or detonation, and it is always desirable to hold the parts of the composition together as much as possible, thus avoiding or at least minimizing the chances of segregation. Such segregation is often a problem with the use of explosives which are dry mixtures and it is considered that in one aspect, the present invention provides means whereby such segregation is at least reduced.

In the present invention, the dry mix explosive ccmposition has added to it a water-in-oil emulsion, which is mixed with the other parts of the explosive composition, the emulsion serving to bond and hold together the parts of the composition so as to avoid or minimize segregation.

Up until this time, it has been known to attempt to overcome or minimize segregation by the use of adhesive or bonding agents, however these have been found to be particularly unsatisfactory especially during mixing, as they become stuck to mixing equipment, and are essentially unsatJsfactory in use. It has however been found that by using a water-in-oil emulsion according to the present invention, the constituent parts of the explosive composition are held or bonded together such as to prevent or minimize segregation, while not being adhered or stuck to each other in such a manner as would be the case if a known adhesive or glue was used.

The water-in-oil emulsion of the present invention preferably consists of a water-based solution of one or more oxidizer salts which are typically nitrates and/or perchlorates held j '4 in the disperse phase in oil by an emulsifier. Other oxidizer ,o salts can however be used. Preferably the oil phase may typically be fuel oil, mineral oil, vegetable oil. paraffin, or any appropriate oil and/or wax materials. It is howe-vr desirable that the oxidizer solution be emulsified and remain as a disperse phase.

By way of example, an explosive composition using the further additive of the present invention can include from 50% to (by weight) dry oxidizer salts, up to 50% (by weight) bulking agent, including vegetable protein matter and up to 60% (by weight) water-in-oil emulsion.

In preferred forms of the invention, the vegetable protein matter is a dry chopped vegetable protein matter containing less than 20% (by weight) water. In the preferred form of the invention, the vegetable protein matter may be in the form of legumes and in particular legumes in the form of nuts and nut shells, such as for example peanut shells and walnut shells. Such vegetable protein matter has been found to be particularly effective in use and have the desired properties for use as a bulking agent according to the present invention. It should be appreciated however, that other appropriate vegetable protein matter can be used to advantage.

It should be appreciated therefore, that in one form of the present invention, the use and addition of a water-in-oil emulsion serves to add a bonding or adhesion to the parts of the composition, without the usual sticky or undesirable effects of known glues or adhesives. The use of the emulsion serves to hold the parts of the composition together so as to avoid, reduce or minimize segregation as referred to hereinbefore.

This invention has been described by way of example only and improvements and modifications may be made to the invention without departing from the scope thereof as defined by the appended claims.

9

Claims

1. A dry mix explosive composition including a bulking agent, comprising from 1 20% (by weight) of a fibrous vegetable protein additCive; said bulking agcnt having a bulk density of from 0.1 0.6 grams per cubic centimetre and said explosive composition having a bulk density of from 0.5 1.1 grams per cubic centimetre.

2. A\ dry mix explosive composition as claimed in claim 1, further including a binding or holding agent in the form of a water-in-oil emulsion.

3. A dry mix explosive composition as claimed in claim 1, further comprising an oxidizer and fuel.

4. A dry mix explosive composition as claimed in claim 1, wherein said bulkL~ig agjent comprises up to 5% (by weight) of said fibrous vegetable -protein additive, said bulking agent having a bulk density of about 0.2 grams per cubic centimetre. A dry mix explosive composition as cl.aimed in claim 1, wherein said hulking agent includes, from 0.5 10% (by weight) lipids.

6. dry mix explosive composition as claimed in claim 1, further comprising dry oxidizer salts and carbonaceous lltdd fuel.

7. A dry mix explosive composition as claimed in claim 6, wherein said dry oxidizer comprises dry oxidizer salts in the form of ammonium nitrate, said explosive composition further including at least I additional ganic nitrate salt.

8. A dry mix explosive composition as claimed in claim 6, wherein said dry oxidizer comprises dry oxidizer salts including ammonium perchlorate.

9. A dry mix explosive composition as claimed in claim I, further comprising a carbonaceous fuel in the form of fuel oil. A dry mix explosive composition as claimed in claim 6, wherein said dry oxidizer is in the form of ammonium nitrate and said explosive composition further includes a fuel sensitizer as a mixture of powdered fuel and metal.

11. A dry mix explosive composition as claimed in claim 6, wherein said dry oxidizer is in the form of ammonium nitrate porous prills and said explosive composition further includes a fuel in the form of fuel oil.

12. A dry mix explosive composition as claimed in claim 1, comprising from 57% 89% (by weight) ammonium nitrate; up to 10% (by weight) calcium nitrate; up to 5% (by weight) sodttio nitrate; up to 30% (by weight) of a molecular explosive; from 3% 6% (by weight) fuel oil and from 5% (by weight) of said bulking agent.

13. A dry mix explosive composition as claimed in claim 1, wherein said bulking agent comprises from 1% 20% (by weight) of said fibrous vegetable protein and from 0,5% (by weight) lipids, said bulking agent having said bulk densqty of from 0.l 0.6 grams per cubic centimetre.

14. A dry mix explosive composition as claimed in claim 1, further including a binding or holding agent in the form of a water-in-oil emulsion consisting of a water based solution of one or more oxidizer salts held in a disperse phase of oil and/or wax, 1 _111 A dry mix explosive composition as claimed in claim 1, comprising 50% 95% (by weight) dry oxidi ts; up to (by weight) of said bulking agent and ii said fibrous vegetable protein additive and up to 60% (by weight) of a water-in-oil emulsion.

16. A dry mix explosive composition as claimed in claim 1, wherein said fibrous vegetable protein additive contains less than 20% (by weight) water. Dated this fifth day of February 1990 CBS EXPLOSIVES PTY LTD I9, Lr-i Its Patent Attorney /1