RU144492U1 - SALT MODULE FOR FORMING A BORE CHARGE UNDER THE CONDITIONS OF CRYOLITZONE - Google Patents

Abstract

A module for the formation of a borehole charge in the cryolithozone conditions, made in the form of a cylinder with a through longitudinal cavity to fill it with explosive material, a size that allows it to be placed in the well, characterized in that it is made of salts that prevent freezing of rocks.

Description

The utility model relates to mining and, in particular, to drilling and blasting operations for loosening permafrost rocks.

For loosening the frozen mass of rocks in the conditions of permafrost, drilling and blasting are carried out. The subsequent excavation of blasted rocks is complicated by their repeated freezing, which complicates their further development by mining machines.

A known design of ice modules for the formation of a borehole charge in a cryolithozone [1] (Prototype).

The disadvantage of this design is that it does not exclude repeated freezing of the blasted rock mass.

The technical task of this utility model was the development of the design of the borehole explosive charge, which prevents re-freezing in the monolith of exploded permafrost rocks.

New in the design, which includes a module for the formation of a borehole charge in the cryolithic zone, made in the form of a cylinder with a through longitudinal cavity to fill it with explosive material, the size of which allows it to be placed in the well, is that it is made of salts that prevent freezing of rocks.

Introduced into the utility model formula, such an essential feature as the fact that the module is made of salt, for example, NaCl (table salt), MgCl ₂ (bischofite), provides explosive salinization of crushed permafrost rocks during explosion of a well, which prevents their repeated freezing, it easily destroyed by earth-moving machinery, does not freeze to the surface of vehicles and working bodies of earth-moving machinery.

The utility model is illustrated by drawings, where Fig. 1 shows a sectional view of the placement of charge from salt explosive modules in a well; figure 2 is a section aa (round shape of constant diameter).

Symbols adopted in the drawings: 1 - frozen soil; 2 - well; 3 - salt module; 4 - a through internal longitudinal cavity of the module of the required configuration; 5 - explosive charge; 6 - stemming module; 7 - detonator cord.

To form a borehole charge from salt modules under cryolithozone conditions in a frozen ground 1, a well 2 is drilled, where a salt module 3 made of cylindrical salt and having a slightly smaller diameter than well 2 is placed. Inside the salt module 3, longitudinal through cavities 4 are made, which on different modules 3 have various configurations necessary to give the borehole charge the desired shape, in which the explosive charge 5 is placed. A continuous salt cylindrical module 6 with a detonating cord 7 placed in it is used to shut the borehole 2.

Table 1 shows reference data on the solubility of sodium, calcium, potassium, and magnesium chlorides depending on temperature. A sign (*) marks the concentrations and temperatures corresponding to the eutectic point for each salt [2]. Salt, being mixed with ice (including in the form of snow), causes its melting (melting). The resulting water-salt solution has a crystallization temperature (freezes) below 0 ° C, which depends on the amount of salt in the solution (the higher the concentration, the lower the crystallization temperature of the solution).

With artificial salinization of frozen soils, their physical and mechanical properties change [3].

A compression test of soil samples salted with sodium chloride solution shows that salinization leads to a significant decrease in temporary resistance. At a solution concentration of 15-20% and a negative temperature of -10 ÷ -20 ° C, the temporary resistance of the soil to compression is approximately the same as at a positive temperature [3].

The dependences presented in Fig. 1 characterize a decrease in the conditionally instantaneous compressive strength of fine-grained sand and incoherent loam with an increase in the concentration of sodium chloride and initial moisture. A more drastic decrease in strength at the same salt solution concentration, humidity, and negative temperature is observed for coarser dispersed media [3].

Table 1 The freezing temperature of solutions of antifreeze reagents. Concentration% Freezing point, ° C NaCl CaCl ₂ MgCl ₂ Kcl 2 -1.2 -1.1 -0.9 four -2.45 -2.3 -1.9 6 -3.75 -3.7 -2.8 8 -5.11 -5.5 -3.8 10 -6.62 -7 -7.7 -4.8 12 -8.28 -9 -10.1 -5.9 fourteen -10.00 -eleven -13.4 -7.0 16 -11.90 -13 -17.4 -8.2 eighteen -14.00 -17 -22.6 -9.6 19.74 * -10.7 * twenty -16.30 -twenty -29.0 21 * -22 -33.5 * 22 -19.00 -24 23.3 * -21.20 * 24 -29

Concentration% Freezing point, ° C NaCl CaCl ₂ MgCl ₂ Kcl 26 -35 28 -43 29.6 * -51 *

Fig. 1. Dependence of conditionally instantaneous strength of frozen soils on compression on the concentration of sodium chloride solution (V _def = 50 mm / min): 1 - loesslike loam w = 20%, T = -20 ° C; 2 - fine-grained sand w = 15%, T = -20 ° C; 3 - fine-grained sand w = 10%, T = -10 ° C.

A known method of producing briquettes-licks from loose or boiled salt with a particle size of 0.01-1.00 mm, having a moisture content of 2-10%, including filling the mold with salt, its compaction, curing and unloading from the mold, characterized in that the mixture is cured is carried out by drying briquettes when heated and / or due to the natural evaporation of moisture [4].

Salt modules 3 are made as follows [4]. Wet loose or evaporated salt with a particle size of 0.01-1.00 mm (humidity 2-10%) fill the form of the desired configuration, salt in the form is compacted. The molded salt is cured by drying by heating and / or by natural evaporation of moisture. In wet salt, water is in the form of a saturated solution of sodium chloride and fills the gaps between the salt particles. When drying, the water evaporates. In the spaces between the salt particles, crystals of salt stand out, which grow together with each other and with particles of salt, forming “bridges” connecting individual salt particles to each other. As a result, all salt particles are bonded. After drying all the moisture, the bulk salt solidifies into one continuous solid mass, forming salt module 3 of the required configuration. Drying of wet salt modules 3 is carried out together with the mold or after removing the wet briquette from the mold.

Salt modules 3 are used as follows: in a drilled well 2 of circular cross section, modules 3 of a certain length (a multiple of the length of a well 2), made of salt and having a cylindrical outer shape smaller than the well 2 of a diameter with through internal cavities 4, are laid on top of each other. Then the internal cavities 4 installed salt modules 3 are filled with initiating and main charges of explosives 5 and with the help of the bottom-hole module 6 made of salt and having a cylindrical outer shape smaller than the well 2 of the diameter of the hole drive stemming of 2 wells.

During the explosion of the explosive charge 5 in frozen ground 1, a crushing zone and a crack formation zone are formed, into which salt from the destroyed salt modules 3 is injected under the influence of gaseous detonation products of explosive 5. The salt penetrating into the cracks interacts with the moisture released during the explosion frozen rocks, and dissolves in it. Salt solutions fill cracks and exclude freezing of frozen rock.

The placement of modules 3 (figure 1) in the well 2 can be carried out using special or known devices, for example, using a manual winch installed in the wellhead 2.

Charging the external surface of the main charge formed with the help of modules 3 when using bulk explosives to increase the efficiency of explosive devices can be carried out by means of mechanization - charging machines.

The advantage of the proposed utility model is the prevention of repeated freezing of exploded permafrost rocks.

Information sources

1. Utility Model Patent No. 65134 of the Russian Federation, Ice Modules for Forming a Borehole Charge in a Cryolithozone // Tkach S.M., Vasiliev P.N. IPC E21C 37/00. Claim 10/18/2006. Publ. 07/27/2007. Bull. No. 21.

2. Goronovsky I.T., Nazarenko Yu.P., Nekryach E.F. Brief reference book on chemistry / Under the general. ed. Acad. USSR Academy of Sciences A.T. Pilipenko. - Kiev: Naukova Dumka, 1987 .-- 833 p.

3. Surikov, V.V. The mechanics of the destruction of frozen soils. - L .: Stroyizdat, Leningrad. Department, 1978.- 128 p.

4. Patent for invention No. 2038792 of the Russian Federation, A method for producing briquettes of licks // Leverah V.I .; Obukhov A.V .; Shmelev V.G .; Kropanev I.S .; Pustosmekhov A.Yu. IPC A23K 1/16, A23K 1/17. Claim 08/19/1992. Publ. 07/09/1995.

Claims (1)

A module for the formation of a borehole charge in the cryolithozone conditions, made in the form of a cylinder with a through longitudinal cavity to fill it with explosive material, a size that allows it to be placed in the well, characterized in that it is made of salts that prevent freezing of rocks.