JPH09208357A - Explosive composition of w/o-type emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an explosive composition of W/O-type emulsion, free from the entrapping of foams in mixing or filling process and homogeneous in weight for every packed piece of explosive owing to excellent fluidity in a mixing work. SOLUTION: This explosive of W/O-type emulsion is composed of an aqueous solution of an oxidant, an oil, an emulsifying agent and fine hollow spheres. The fine hollow spheres have a true specific gravity in the range of 0.10-0.35, the glass-made fine hollow spheres has a water float rate of >98 volume %, and the surfaces of the glass-made fine hollow spheres are coated with a water- repellent material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water-in-oil (hereinafter abbreviated as W / O) emulsion explosive composition that is widely used for industrial blasting operations such as Susumu Kidohori, quarrying and mining. Is.

[0002]

2. Description of the Prior Art W / O emulsion explosives have been disclosed for the first time in US Pat. No. 3,161,551.
Various W / O emulsion explosives have been proposed according to the purpose. Those W / O emulsion explosives are
Basically, it comprises a continuous phase composed of a carbonaceous fuel, a dispersed phase composed of an aqueous solution of an inorganic oxidic acid salt, an emulsifying agent and a bubble retaining agent. Micro hollow spheres are usually used as the cell-holding agent, and a W / O emulsion explosive having a wide range of sensitivity from booster detonation to detonator detonation has been obtained by selecting it. Since these W / O type emulsion explosives do not contain explosives in their composition, they are more safe in handling than colloidal dynamite, and their use is gradually spreading. However, recently, it has been desired to further improve the uniformity of product quality, and for that purpose, it is necessary to uniformly disperse the cell-holding agent. For example, a W / O emulsion explosive using a micro hollow body having a water floating rate of 93 to 98% by volume has been disclosed for the purpose of enhancing the miscibility of glass micro hollow spheres in a W / O emulsion explosive. (Japanese Patent Laid-Open No. 3-93690)
Issue).

[0003]

A W / O type emulsion explosive is first prepared by using an aqueous oxidizer solution, oils, and an emulsifier.
It is obtained by producing an O-type emulsion, and then adding the hollow microspheres and mixing with stirring. Generally W / O
The type emulsion has an extremely high viscosity and usually has a grease-like or mayonnaise-like property. The highly viscous W / O emulsion is stirred and mixed with minute hollow spheres having a small specific gravity to make the mixture uniform, and then the product is packaged in paper or a synthetic resin tube. As a method of packaging with paper, for example, a filling type in which a W / O type emulsion explosive is injected into a paper tube previously manufactured by a paper tube manufacturing machine using a Caltex machine (manufactured by NEEPMAN, trade name),
Alternatively, a method in which a W / O emulsion explosive cut into a predetermined shape is wrapped with paper by a Rolex machine (manufactured by NEEPMAN, trade name) is generally used. The packaging must be adjusted so that the prescribed dose is obtained, but the dose is adjusted by controlling the measurement of the normal volume rather than pre-weighing each dose and packaging. The method is taken.

However, as described above, the W / O type emulsion explosive has a high viscosity, and as the temperature decreases, the viscosity further increases. Therefore, it is easy to hold air while mixing the micro hollow spheres, and once the air is held, the air does not easily come out. In addition, since the hollow microspheres cannot be uniformly dispersed, the hollow microspheres partially exist in a cluster, and there is a problem that voids are formed therein. In such a case, the weight of the W / O emulsion explosive cannot be accurately dispensed due to voids in the explosive, and the amount of the drug is reduced by that amount, resulting in non-uniform explosive force and detonation speed. It was An object of the present invention is to provide a W / O emulsion explosive composition having a uniform packaging dose.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve this problem, and as a result, when a specific glass micro hollow sphere was used, it was embraced during admixture of a W / O emulsion explosive. It has been found that the amount of air taken in is extremely small and the fluidity of the explosive is good, so that voids are eliminated and the amount of the packaged medicine becomes uniform. That is, the first invention is a water-in-oil emulsion explosive consisting of an aqueous oxidizer solution, oils, an emulsifier, and micro hollow spheres, wherein the micro hollow spheres have a true specific gravity of 0.10 to 0.35, and A water-in-oil emulsion explosive composition, which is a glass-made minute hollow sphere having a water floating ratio of more than 98% by volume. A second invention is the water-in-oil emulsion explosive composition according to the first invention, wherein the surface of the glass micro hollow sphere is coated with a water-repellent substance.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The hollow microspheres used in the present invention are made of glass, and their true specific gravity is ASTM.D.
The value measured by the air displacement pycnometer method described in -2840 is in the range of 0.10 to 0.35, and the floating rate with respect to water measured by the method described below exceeds 98% by volume. .

(Measurement Method of Water Floating Rate) (1) About 130 cc of micro hollow spheres are weighed in a 250 cc cylinder and tapped 500 times according to ASTM B-527. The amount of minute hollow spheres having a volume of 100 cc is adjusted many times. The final 100cc is tapped 300 more times. (2) Add water to about 3/4 of a graduated 500 cc separation flask and add 100 cc of the above-mentioned micro hollow spheres. (3) Shake the flask well and let it stand for 10 minutes. (4) Hold the bottom of the flask and shake the floating part again. Let stand for 5 minutes. (5) The volume of sediment (Vs) is read, and the floating rate is calculated by the following formula. Floating rate = 100-Vs

If the specific gravity of the micro hollow spheres is smaller than 0.10, the micro hollow spheres will crack during mixing, leading to variations in the specific gravity of the W / 0 type emulsion explosive and non-uniformity of the dose of each one. . The specific gravity of the hollow microspheres is 0.35
If it exceeds, the sensitivity of the W / O type emulsion explosive tends to deteriorate. If the water suspension ratio is 98% by volume or less, the number of effective bubbles contained in the W / O emulsion explosive after admixture is small, so the amount of micro hollow spheres added is large and the explosive power is small. Tends to become. The amount of the micro hollow spheres used usually depends on the specific gravity of the micro hollow spheres used and the like, but is 0.2 to 10% by weight based on the total composition,
It is preferably used in the range of 0.5 to 7% by weight. 0.
If it is less than 2% by weight, the sensitivity of the W / O emulsion explosive is lowered, and conversely, if it is more than 10% by weight, the power of the W / O emulsion explosive tends to be lowered. Further, from the viewpoint of maintaining the sensitivity of the explosive, the micro hollow spheres used in the present invention have a specific gravity of 1.40 of the W / O emulsion explosive thus produced.
It is preferably used in an amount range of g / cc or less. More preferably, the specific gravity of the completed W / O emulsion explosive is used within the range of an amount of 1.30 g / cc or less.

The fine hollow spheres are mixed with other fine hollow spheres, for example, one or more kinds of other glass fine hollow spheres such as glass microspheres, shirasu balloons, perlites, resin microballoons and multi-cellular organic foams. You may use it.
And the amount is usually 10% by weight or less.

The surface of the glass micro hollow sphere may be coated with a water-repellent substance. Examples of substances used for coating include low-molecular silane coupling agents, high-molecular silane coupling agents, fluorine-based surfactants, paraffin wax, polyfluoroalkanes, stearic acid, fluorine-containing methacrylates (or fluorine-containing acrylates). ) System lubricants and resins such as polymethylmethacrylate and polystyrene.

The oxidant aqueous solution used in the present invention is W / O.
It is an aqueous solution of an inorganic oxidizing salt that constitutes a dispersed phase in a type emulsion explosive composition, and it includes all those conventionally used for W / O type emulsion explosives. Examples of the inorganic oxidizing salt include ammonium nitrate,
Alkali metals such as sodium nitrate and calcium nitrate, nitrates of alkaline earth metals, ammonium perchlorate, and inorganic perchlorates such as sodium perchlorate are used.
Ammonium nitrate alone or a mixture of ammonium nitrate and another inorganic oxidizable salt is preferred from the viewpoint of solubility in water and dissolution temperature. The blending ratio of these inorganic oxidizing salts is generally 5 to 90% by weight, and usually 40 to 80% by weight, based on the total composition in the explosive composition. W / O if less than 5% by weight
The explosive power of the type emulsion explosive is weak, and conversely, when it exceeds 90% by weight, the stability of the W / O type emulsion explosive decreases. These inorganic oxidizing salts are used as an aqueous solution, and the mixing ratio of water in this case is 3 to 30% by weight, preferably 5 to 25% by weight based on the total composition in the explosive composition.

The oils used in the present invention are carbonaceous fuels that form the continuous phase in W / O emulsion explosive compositions, and are all those conventionally used in W / O emulsion explosives. Included. For example, paraffin hydrocarbons, olefin hydrocarbons, naphthene hydrocarbons, aromatic hydrocarbons, saturated or unsaturated hydrocarbons, petroleum refined mineral oils, lubricating oils, hydrocarbons such as fluid paraffin, and nitro hydrocarbons. Waxes such as hydrogen derivatives, unrefined or refined microcrystalline wax derived from fuel oil and petroleum, paraffin wax, montan wax which is mineral wax, whale wax which is animal wax, bees wax which is insect wax, etc. Is. These are used alone or as a mixture. From the viewpoint of stability over time, carbonaceous fuels that are preferable are microcrystalline wax and petrolatum, and particularly preferable waxes are microcrystalline wax.

Further, for the purpose of adjusting the drug quality, a low molecular weight hydrocarbon polymer such as petroleum resin, low molecular weight polyethylene, low molecular weight polypropylene, etc. may be used in combination with the carbonaceous fuel component. And these are normally used in 90 weight% or less of oils. Oils are usually 0.1-10 against explosives
%, Preferably 1 to 5% by weight. If it is less than 0.1% by weight, the stability of the W / O emulsion explosive will be poor, while if it exceeds 10% by weight, the explosion energy of the W / O emulsion explosive tends to be lowered.

The emulsifier used in the present invention is conventionally W /
Any of those used for O-type emulsion explosives can be used. For example, sorbitan monolaurate, sorbitan monooleate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan diolate, sorbitan trioleate, and other sorbitan fatty acid esters, stearic acid monoglyceride mono- or diglyceride, poly Oxyethylene sorbitan fatty acid ester, oxazoline derivative, imidazoline derivative, phosphoric acid ester, fatty acid alkali metal salt or alkaline earth metal salt, primary, secondary or tertiary amine salt, etc., and these are one kind or two or more kinds. Used as a mixture of. Of these, the preferred emulsifier from the viewpoint of emulsion stability is sorbitan fatty acid ester. The mixing ratio of these emulsifiers is 0.
It is 1 to 10% by weight, preferably 1 to 5% by weight. 0.
If it is less than 1% by weight, the stability of the W / O emulsion explosive will be poor, and conversely if it is more than 10% by weight, the explosion energy of the W / O emulsion explosive will tend to be lowered.

In the W / O emulsion explosive composition according to the present invention, metal powder such as aluminum powder and magnesium powder, organic powder such as wood powder and starch are used to increase the explosive power and improve the drug quality of emulsion. You may add in order to do. The W / O emulsion explosive composition of the present invention can be produced by a known method, for example, by first mixing oils and an emulsifier with an aqueous oxidant solution and stirring the mixture at high speed to produce a W / O emulsion.
It is obtained by adding fine hollow spheres and, if necessary, metal powder, organic powder, etc., and stirring and mixing them uniformly with a kneader. The composition is packaged with paper or a synthetic resin film in a packaging device to obtain a product.

[0016]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 First, 76.3 parts by weight of ammonium nitrate and 4.5 parts by weight of sodium nitrate were added to 11.0 parts by weight of water and dissolved by heating to obtain an oxidant aqueous solution at about 90 ° C.
On the other hand, 1.7 parts by weight of sorbitan monooleate and microcrystalline wax (manufactured by Esso Standard Oil Co., Ltd.,
Trade name: Esmax 160) 3.4 parts by weight of the mixture was heated and melted to obtain a combustible agent mixture of about 90 ° C. Guide these oxidant aqueous solution and combustible agent mixture to the emulsifying device,
A W / O emulsion was obtained. This W / O type emulsion has a glass microballoon having a true specific gravity of 0.22 and a water floating rate of 99% by volume (trade name: Qcel-, manufactured by PQ, USA).
500) 3.1 parts by weight was added and mixed using a vertical mixer to obtain a W / O emulsion explosive composition. This W /
25mm prefabricated O-type emulsion explosive composition
Filling machine for diameter paper cylinder (made by NEEPMANN, trade name:
About 100 g was mechanically filled with Caltex (the same applies hereinafter). Twenty obtained explosive package samples were taken and the weight was measured to calculate the average value, standard deviation and the like. The composition ratio is shown in Table 1.
The calculation results based on the measurement results are shown in Table 3, respectively.

[0017]

[Table 1]

Comparative Example 1 First, 74.9 parts by weight of ammonium nitrate and 4.5 parts by weight of sodium nitrate were added to 11.0 parts by weight of water and dissolved by heating to obtain an oxidant aqueous solution at about 90 ° C.
On the other hand, 1.7 parts by weight of sorbitan monooleate and microcrystalline wax (manufactured by Esso Standard Oil Co., Ltd.,
Trade name: Esmax 160) 3.4 parts by weight of the mixture was heated and melted to obtain a combustible agent mixture of about 90 ° C. Guide these oxidant aqueous solution and combustible agent mixture to the emulsifying device,
A W / O emulsion was obtained. This W / O emulsion has a glass microballoon with a true specific gravity of 0.27 and a water floating rate of 95% by volume (manufactured by Asahi Glass Co., Ltd., trade name: Z-2).
4.5 parts by weight of 7) were added and mixed using a vertical mixer to obtain a W / O type emulsion explosive composition. This W / O emulsion explosive composition was mechanically filled in a paper cylinder having a diameter of 25 mm prepared in advance with about 100 g by a filling type loading machine. 20 pieces of the obtained explosive package samples were taken and the weight was measured. The composition ratios are shown in Table 2, and the calculation results based on the measurement results are shown in Table 3.

[0019]

[Table 2]

[0020]

[Table 3]

Example 2 10.4 parts by weight of water was added to 80.3 parts by weight of ammonium nitrate and heated to obtain an oxidant aqueous solution at about 90 ° C. on the other hand,
A mixture of 3.5 parts by weight of microcrystalline wax (manufactured by Esso Standard Petroleum Co., Ltd., trade name: Esmax 160) and 1.8 parts by weight of sorbitan monooleate is heated and melted to form a combustible mixture at about 90 ° C. Obtained. The oxidant aqueous solution and the combustible agent mixture were introduced into an emulsifier to obtain a W / O type emulsion. This W / O emulsion has a glass microballoon with a true specific gravity of 0.19 and a water floating rate of 99% by volume (trade name: Qcel-2106, manufactured by PQ, USA).
Add 3.0 parts by weight and mix using a vertical mixer to obtain W / O
A type emulsion explosive composition was obtained. This W / O type emulsion explosive composition was packaged in a size of 40 mm in diameter and about 500 g in weight by using a Rolex packaging machine (manufactured by NEEPMAN, trade name). 20 pieces of the obtained explosive package samples were taken and the weight was measured. The composition ratios are shown in Table 1, and the calculation results based on the measurement results are shown in Table 3.

Comparative Example 2 11.4 parts by weight of water was added to 80.3 parts by weight of ammonium nitrate and heated to obtain an oxidizing agent aqueous solution at about 90 ° C. on the other hand,
A mixture of 3.5 parts by weight of microcrystalline wax (manufactured by Esso Standard Oil Co., Ltd., product name: Esmax 160) and 1.8 parts by weight of sorbitan monooleate is heated and melted to obtain a combustible mixture of about 90 ° C. It was The oxidant aqueous solution and the combustible agent mixture were introduced into an emulsifying device to obtain a W / O type emulsion. To this W / O type emulsion, 3.0 parts by weight of glass microballoons having a true specific gravity of 0.20 and a water floating rate of 96% by volume (manufactured by US 3M, trade name: K20) were added, and a vertical mixer was used. And mixed to obtain a W / O type emulsion explosive composition. This W / O emulsion explosive composition was packaged in a size of 40 mm in diameter and about 500 g in weight using a Rolex packaging machine. The obtained explosive package sample 20
Pieces were taken and weighed. The composition ratios are shown in Table 2, and the calculation results based on the measurement results are shown in Table 3.

Example 3 Ammonium nitrate 52.2 parts by weight, sodium nitrate 1
To 1.2 parts by weight of calcium nitrate and 12.4 parts by weight of calcium nitrate, 11.2 parts by weight of water was added and heated to obtain an oxidant aqueous solution at about 80 ° C. On the other hand, a mixture of 4.3 parts by weight of liquid paraffin and 3.5 parts by weight of sorbitan sesquioleate was heated and melted to obtain a combustible agent mixture at about 70 ° C. The oxidant aqueous solution and the combustible agent mixture were introduced into an emulsifying device to obtain a W / O type emulsion. Glass micro-balloon (made by 3M Company in the United States,
The surface of the product name: K25) was treated with a silane coupling agent (methacryloxysilane) to impart water repellency. The true specific gravity of this product is 0.25, and the water floating ratio is 100%. W
3. Add this glass microballoon to the / O emulsion.
0 parts by weight was added and mixed using a vertical mixer to obtain a W / O type emulsion explosive composition. This W / O type emulsion explosive composition was used to measure a diameter of 30 using a polytube packing machine.
It was packaged in a size of mm and weight of about 200 g. 20 pieces of the obtained explosive package samples were taken and the weight was measured. The composition ratios are shown in Table 1, and the calculation results based on the measurement results are shown in Table 3.

Comparative Example 3 52.2 parts by weight of ammonium nitrate and 1 of sodium nitrate
2.4 parts by weight and 12.4 parts by weight of calcium nitrate to 1 part of water
1.2 parts by weight was added and heated to obtain an oxidizing agent aqueous solution at about 80 ° C. On the other hand, a mixture of 4.3 parts by weight of liquid paraffin and 3.5 parts by weight of sorbitan sesquioleate was heated and melted to obtain a combustible agent mixture at about 70 ° C. The oxidant aqueous solution and the combustible agent mixture were introduced into an emulsifying device to obtain a W / O type emulsion. This W / O emulsion has a true specific gravity of 0.2
5. Add 4.0 parts by weight of glass microballoon (product name: K25, manufactured by US 3M Co., Ltd.) having a water floating rate of 96% by volume, and mix using a vertical mixer to prepare a W / O emulsion explosive composition. Obtained. This W / O emulsion explosive composition was used in a poly tube packaging machine to have a diameter of 30 mm and a weight of about 2
It was packaged in a size of 00 g. 20 pieces of the obtained explosive package samples were taken and the weight was measured. The composition ratios are shown in Table 2, and the calculation results based on the measurement results are shown in Table 3.

[0025]

[Effect of the Invention] From the weight measurement results shown in Table 3, comparing the corresponding Examples and Comparative Examples, it can be seen that the Examples have smaller weight variations. When the sample of the comparative example was weighed and then the packaging was broken and the condition was observed, a hollow portion that seems to be a trapped bubble during mixing or loading may be seen, which is the reason for the large variation in weight. It has been found. In the example, no such hollow portion is found, and the weight after packaging is well matched. In addition, a W / O type emulsion explosive composition having good fluidity in the mixing operation and having a uniform weight in packaging can be obtained. When the explosive package samples obtained according to the examples of the present invention were detonated by an ordinary test method, all exhibited a predetermined performance.

Claims (2)

[Claims] 1. In a water-in-oil emulsion explosive consisting of an oxidizing agent aqueous solution, oils, an emulsifier, and micro hollow spheres, the micro hollow spheres have a true specific gravity of 0.10 to 0.35,
A water-in-oil emulsion explosive composition comprising glass micro hollow spheres having a water floating ratio of more than 98% by volume. 2. The water-in-oil emulsion explosive composition according to claim 1, wherein the surface of the glass micro hollow sphere is coated with a water-repellent substance.