RU2416782C1 - Charging method of emulsion explosive compounds - Google Patents

Abstract

FIELD: explosives.

SUBSTANCE: method provides for delivery of emulsion explosive by means of pump to charging hose and during transportation via the latter of components of emulsion explosive components the supply to annular gap between the hose wall and the flow of water composition with surface-active substance. Alkyl benzene sulphonate (NP-1 sulphanole) or alkyl sulphate of secondary alcohol (penta-surface active substances) in quantity of 0.05-0.1% is used as surface active substance.

EFFECT: introduction of surface active substances allows reducing inter-phase surface tension between emulsion explosives and wall of charging hose, which considerably reduces the pressure during the charging process and excludes the break of the charging hose.

2 cl, 1 tbl

Description

The present invention relates to methods for loading emulsion explosive compositions used in mining types of blasting.

Currently developed emulsion compositions of various types and applications, including for underground blasting. Common features of all emulsion explosives and methods for their preparation are the preparation of an aqueous phase from a solution of oxidizing salts and a combustible hydrocarbon phase containing an additive of a surfactant called an emulsifier at an elevated temperature and mechanically mixing in the form of an individual substance or a complex composition of several components. The mass obtained as a result of this procedure is called a “matrix emulsion”, suggesting the possibility of adding other ingredients, for example, such as an aqueous solution of chemicals for sensitizing gas saturation, or solid porous particles of microspheres, or energy fuel from metal powders and (or) granules of ammonium nitrate. All components are predominantly added during loading by special mixing and charging machines. As examples of these emulsion explosives, one can cite the patents of the Russian Federation No. 2123488, No. 1783759. These emulsion explosives manufactured in mixing-charging machines on charging blocks of quarries are usually sensitized with an aqueous solution of sodium nitrite with a concentration of 5-30%, dispersing it with the help of static or dynamic mixers mounted together with other units on the chassis of charging machines. At the same time, during the charging process, it is necessary to transport emulsion explosives over relatively large distances (several tens of meters) to wells or holes through a charging hose, the diameter of which is up to 25 mm. Naturally, because of the high viscosity of the emulsion explosive, high pressure develops in the hose, which can lead to rupture of the charging hose with traumatic consequences for the operating staff. Often, in order to reduce the pressure in the charging hoses, water is supplied through special devices. However, for some types of mixed emulsion explosives and especially with granules, these measures are insufficient. For example, a charging device according to the patent of the Russian Federation 2312301 and a device for preparing and loading wells with the mixed emulsion explosive according to the patent 2163344 are known, in which the internal resistance in the hose is reduced by supplying clean water in a ring stream between the wall of the charging hose and the flow of the emulsion composition under pressure.

However, when charging, a partial mixing of the emulsion explosive flow and water occurs, due to which the resistance increases along the hose and, as a result, the pressure in it increases, which can lead to its rupture.

Closest to the claimed invention is a method for loading wells with emulsion explosives according to the patent of the Russian Federation 1457501, where the mixing of the components of the emulsion explosives mixture occurs after exiting the pump directly in front of the charging line in the mixer and is carried out by dividing the explosive stream into multiple jets by pins along a helical line and water is separately supplied through the ring to the charging hose.

The technical task of the proposed solution is to improve the method of charging the emulsion explosives by injection through the charging hoses, which consists in the fact that the technique of reducing the interfacial surface tension between the emulsion explosives and the wall of the charging hose is applied, which significantly reduces the pressure during charging.

The implementation of this task is achieved by the fact that a surfactant is introduced into the water in the mixing and charging machine, which is fed into the charging hose. It is known that the greatest influence on the formation of the hydrophilic surface of any pipeline is exerted only by water-soluble surfactants. The effect of surfactants on selective wetting was studied on substances that are most widely used in industry. Of the anionic surfactants, we studied: alkylbenzene sulfonates — sulfonol NP-1 and sulfonol NP-3, alkyl sulfates of secondary alcohols containing 32% of the active substance, disodium salt of alkenyl sulfosuccinic acid (CSN). The selected reagents were used to determine the surface tension of the aqueous solution at the interface between the emulsion and the charging hose. The surface activity of a substance is determined by its chemical structure and its state of aggregation in solution. For example, it is known that surfactants in which hydrocarbon radicals have a branched structure are the best wetting agents, the representative of which is alkylaryl sulfonate based on propylene tetramer (sulfonol NP-1). The kinetic wetting value characterizing the rate of surfactant adsorption at the phase boundary is determined by the loading time of a standard sample of hydrophobic coal powder from the surface of the surfactant solution into the volume of liquid. The lower the kinetic wetting value, the higher the rate of surfactant adsorption at the interface and the greater the surface activity of the reagent. The highest surface activity is observed in aqueous solutions of block copolymers of ethylene oxide and propylene (disolvan, proxanol, proxamine), sulfonols and alkyl sulfates of secondary alcohols (pentapav). Of the surfactants studied, the best indicators were obtained when sulfonol (TU 6-01-1612839-90) and pentapava-430 (TU 2481-019-40245042-01) were introduced into water.

Comparative results of assessing the effect of the amount of surfactant additives in water on the pressure in the charging hose according to the prototype and the present invention are presented in the table.

The amount of additive in water,% Charging hose length, m Charging pressure, atm No surfactant 10 4.1 twenty 8.2 thirty 14.6 fifty the gap Sulfonol 0.01 10 3.4 NP-1 0.01 twenty 6.9 0.01 thirty 12.1 0.01 fifty Break 0.05 10 2.5 0.05 twenty 5,6 0.05 thirty 9,4 0.05 fifty 14.3 0.1 10 1.9 0.1 twenty 4.2 0.1 thirty 7.6 0.1 fifty 10.1 0.2 10 1.8 0.2 twenty 4.3 0.2 thirty 6.8 0.2 fifty 9.7 Pentapav-430 0.01 10 3.2 0.01 twenty 6.5 0.01 thirty 11.3 0.01 fifty Break 0.05 10 2.2 0.05 twenty 5.1 0.05 thirty 8.6 0.05 fifty 13.5 0.1 10 1,6 0.1 twenty 3.9 0.1 thirty 7.6 0.1 fifty 9.2 0.2 10 1.4 0.2 twenty 3.8 0.2 thirty 6.9 0.2 fifty 9.1

The proposed charging method provides the operational characteristics of the emulsion explosives at the level of the prototype method, but significantly reduces the pressure in the charging hose. From the data of the table it follows that the use of surfactants such as sulfonol and pentapava can reduce the pressure when charging emulsion compositions and to prevent rupture of the charging hose. The amount of surfactant should be in the range of 0.05-0.1%.

Claims (2)

1. A method of charging emulsion explosive compositions, comprising pumping a composition mass into a charging hose by pumping water into an annular gap between the wall of the hose and the composition stream, characterized in that a surfactant is introduced into the water. 2. The method of charging emulsion explosive compositions according to claim 1, characterized in that alkylbenzenesulfonate or secondary alcohol alkyl sulfate in an amount of 0.05-0.1% is used as a surfactant.