Nippon Oil Fats Co., Ltd.

Kajima Corporation

Nippon Oil and Fats Company, Limited and Kajima Corporation

Katsuhide Hattori

Yoshiaki Fukatsu

Masao Takahashi

Hiroshi Sakai

Shigeru Kakino

Yoji Tasaki

Koichi Kurokawa

Akio Torii

Hideo Moriyama

Hidekazu Sakakibara

Fumio Takeuchi

Fumio Matsui

Mikio Takano

Toshifumi Sato

Kohji Edamura

Shin Aono

Akihiro Tanaka

Yoshikazu Hirosaki

Toshikazu Miyajima

Motoyuki Amano

Katsura Ogasawara

An excellent water in oil type emulsion explosive having both of a superior handling property and a good aging initiating sensitivity at low temperatures and at small calibers, is provided by using a specific low molecular weight polyethylene as the carbonaceous fuel in the emulsion explosive.

Water in oil type emulsion explosive

A laser beam-detonatable blasting cap containing secondary explosives charged therein in the upper and lower portions, wherein the explosive charged in the upper portion contains a laser beam-absorbing black material and is contacted with an optical fiber at the top. The loading density of the explosive charged in the lower portion is higher than that of the explosive charged in the higher portion, and only the side of the explosive charged in the upper portion is surrounded with a restraining wall. The blasting cap can be easily and surely detonated by a laser beam having a low peak output power generated by means of a pulse-oscillation system without using Q-switching or a continous oscillation system.

Laser beam-detonatable blasting cap

A water-in-oil emulsion explosive composition containing hollow microspheres obtained by firing volcanic ash and having a bulk density of 0.05-0.1 and an average particle size of 10-100 .mu.m has improved explosion performance and safety over water-in-oil emulsion explosive composition containing conventional hollow microspheres.

Water-in-oil emulsion explosive composition

A gas-retaining agent having a particle size of 177-3,000 .mu.m is effective for improving the safety of water-in-oil emulsion explosive compositions against methane and coal dust and for improving the sympathetic detonability of the explosive compositions without deteriorating their strength.

A water-in-oil emulsion explosive composition containing specifically limited hollow microspheres consisting of neutral or weakly acidic hollow microspheres coated with a coating material has a high consistency without deteriorating its storage stability in initiation sensitivity in a small diameter cartridge, and can be safely and easily handled.

A water-in-oil emulsion explosive comprising an aqueous solution of inorganic oxidizer, an oil, an emulsifier and hollow microspheres, and having high low-temperature detonability and storage stability can be produced without causing breakage of the hollow microspheres through particular emulsifying and kneading steps, in which emulsifying step the aqueous solution of inorganic oxider, the oil and the emulsifier are fully emulsified into a water-in-oil emulsion in an emulsifying machine having a novel structure, and in which kneading step the resulting water-in-oil emulsion is kneaded together with the hollow microspheres by means of agitating blades, said agitating blades being arranged in the kneader and carrying out concurrent by rotary motion and up and down movements.

Method of producing a water-in-oil emulsion explosive

A water-in-oil emulsion explosive, comprising aqueous inorganic oxidizer solution, oil, emulsifier and hollow microspheres, and having high low-temperature detonability and storage stability can be produced without causing breakage of the hollow microspheres through a specifically limited kneading method, wherein agitating blades fitted to an agitating shaft in a kneader are subjected to up and down movements in the axial directions of the agitating shaft and concurrently to a rotary motion to knead homogeneously a water-in-oil emulsion formed of the aqueous solution of inorganic oxidizer, oil and emulsifier, together with the hollow microspheres.

Method of producing a water-in-oil emulsion exposive

An aqueous solution-type oxidizing agent composition consisting of an aqueous solution containing an oxidizing agent, which consists of ammonium nitrate as a main component and an inorganic chlorate, and further containing a water-soluble phosphate as a stabilizer, which is stable, inhibits the decomposition of ammonium nitrate, and has high storage stability.

Stable aqueous solution-type oxidizing agent composition for explosives

A method of producing water-in-oil emulsion explosive by carrying out emulsification and kneading of a raw material mixture in one step is disclosed. In the method, hollow microspheres and a mixture of an aqueous solution of inorganic oxidizer, an oil and an emulsifier are separately supplied into a common passage of an emulsifying and kneading machine; the hollow microspheres and the mixture are emulsified and kneaded on the surface of a disc arranged on the downstream side of the disc, while rotating the disc; the emulsified and kneaded mixture is flowed down from the outer peripheral portion of the disc into a kneading room formed under the disc, while continuing the emulsification and kneading; the emulsified and kneaded mixture is fully emulsified and kneaded in the kneading room; and then the resulting water-in-oil emulsion explosive is taken out from the kneading room. The method is shorter and simpler in the production step, is more effective for energy saving, is higher in the safeness in the process control and is more practicable than conventional methods.

Method of producing water-in-oil emulsion explosive

A water-in-oil emulsion explosive composition having excellent storage stability, low-temperature detonability and explosion reactivity is disclosed, which comprises (a) a disperse phase formed of an inorganic nitrate consisting mainly of ammonium nitrate, (b) a continuous phase formed of an oil, (c) an emulsifier, (d) hollow microspheres and/or a chemical foaming agent, and (e) an inorganic chlorate.

Water-in-oil emulsion explosive compositions containing (e) nitromethane gelatinized product obtained by mixing nitromethane with a gelatinizer for nitromethane and (f) hollow microspheres and/or (g) bubbles formed from a chemical foaming agent in a water-in-oil emulsion composition consisting of (a) ammonium nitrate or ammonium nitrate and the other inorganic oxidizer salts, (b) water, (c) an oil and/or wax and (d) a sorbitan fatty acid ester surfactant.

A water-in-oil emulsion explosive composition consisting of ammonium nitrate or a mixture of ammonium nitrate and the other inorganic oxidizer salts, water, oil and/or wax, at least one emulsifier of the group consisting of potassium octadecylsulfonate and sodium N-methyl-N-alkyl(beef tallow)-taurate and at least one of hollow microspheres and bubbles generated from a chemical foaming agent is excellent in the emulsion stability in storage, detonability at low temperature, explosion reactivity and sympathetic detonability.

A water-in-oil emulsion explosive composition consisting of ammonium nitrate or a mixture of ammonium nitrate and the other inorganic oxidizer salts, water, oil and/or wax, 1-hydroxyethyl-2-imidazoline derivative as an emulsifier and at least one of hollow microsphere and bubbles generated from a chemical foaming agent is excellent in the emulsion stability in storage, low temperature detonability and explosion reactivity.

Water-in-oil emulsion explosive composition with imidazoline derivative

A water-gel explosive comprising ammonium nitrate alone or in admixture with other inorganic oxidized acid salt, water, nitroparaffin having 1 to 3 carbon atoms, a gelatinizing agent for water, a gelatinizing agent for nitroparaffin, glass hollow microspheres and an amide has a high initiation sensitivity even at low temperature.

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Chita, Japan

Katsuhide Hattori