Ìàãèñòð ÄîíÍÒÓ Øàòðàâêà Àíàñòàñèÿ Íèêîëàåâíà


Faculty: Environment and Chemical Technology

Speciality: Chemical technology of high molecular connections

Theme of master's work:

Research of properties of permissible explosives

Scientific adviser: Mangos Juriy








About author

Àíãëèéñêèé ÿçûê

Ðóññêèé ÿçûê

 Óêðàèíñêèé ÿçûê

Abstract


Introduction

     Continuous development of industry requires a steady increase in coal production, because it is main type of energy and chemical raw materials. Blasting operations are used for coal production. Explosions of methane in coal mines have been observed starting from the XVIII century. Because mined beds occur at a great depth and have a high volume of gas. Coal seams are bedded a depth greater than 720 m in the mines of the Donbass. Approximately 90% of mines in Ukraine are gas.
     Only permissible explosives are used in coal mines dangerous on gas and slack explosion.
     The use of permissible explosives V and VI classes is significantly reduced in recent years. Sales volume of permissible explosives V classes came down in three times more. The recession in demand is related to the high cost and low efficiency in blasting. The available task is development of new mixtures of permissible explosives. They will posses high safety properties and relatively low cost price. The purpose of my work is to study the ion-exchange of explosives on the basis of ammonium sulfate.

The new permissible explosive

     The reaction between sodium nitrate with ammonium chloride is basis of ion exchange process, which was proposed by Bihel in 1902. In 2003, Zenin proposed to use as ion pairs of sodium nitrate and ammonium sulfate. A prototype of the explosive was based on uglenit P52. Its choice is based on the following information:
  • Responsible for inhibition combustion of methane is metal, which is part of the salt. The most intense inhibitors are salts of alkali metals. Halide salts are most active inhibitors by anion, besides fluorides are better than chloride, sulfates is better than carbonates and bicarbonates;
  • Activity of the inhibitor grows with the increase of mass part of metal in the salt. Sodium chloride is 39.3%, in sulfate is 32.4%;
  • Sodium sulfate decreases flash temperature of the methane-air mixture on 70 C0.
  • Ammonium sulfate is more accessible and cheap material, and so permissible explosives based on it will posses a lower cost.

Table 1
The component composition of explosives
Component Name Norma% for explosives mark
uglenit P52 uglenit 10P uglenit 13P Prototype
Nitro ether (a mixture of nitroglycerin
and diethyleneglycoldynitratå (60-70): (40-30))		 11.5 10 13 11.5
Ammonium chloride 27 32 30 -
Ammonium Sulfate - - - 28.5
Sodium nitrate 39 48 36.4 36
Calcium stearate or zinc stearate 0.7 0.5 0.8 0.7
Cotton colloidal 0.3 0.3 0.3 0.3
Polystyrene, frothed, PSV-S 1 1.5 2.5 1
Ammonium nitrate waterproof 15 - 15 15
Sodium salt carboxymethylcellulose 2 2 2 2
Calcium carbonate 5 5 5 5

The calculation of energy characteristics

     The calculation of energy characteristics was performed on a computer, by meansof Mathcad. the calculation explosive transformation heat, the temperature of the explosion, the total ideal of the explosion, efficiency of the explosion and the pressure of explosion products, equations of explosive transformation are presented in the program. Equations of explosive transformation for permissible explosives V classes were obtained after the calculation.
     The reaction of explosive transformation for uglenit 13P is


     The reaction of explosive transformation for uglenit P52 is


     The reaction of explosive transformation for prototype is


     The reaction of explosive transformation for uglenit 10P is


     The calculated energy parameters PE shown in Table 2
Table 2
Energy parameters
Parameter Uglenit 13P Uglenit P52 Uglenit 10P Prototype
Oxygen balance,% -4.843 0.586 -1.2 1.3
Heat of explosion, kcal/kg 700,662 667 609,239 592,68
Explosion temperature, K 2152 2101 2020,2 1859,9
Initial gas pressure, kgf/sm2 4241,9 4205 3530 3498
Efficiency 0,658 0,67 0,63 0,63
Total ideal of the explosion, kcal/kg 460,75 446,17 385,02 375,13
The volume of explosion products, l/kg 625,22 634,6 554,24 596,58


     Tests on safety properties uglenit P52 and prototype were carried out on the plant Petrovsky. Critical mass of an explosive, which no inflammation of the methane-air mixture was determined. For uglenita P52, this mass is 300 g, for a prototype of the mass of the limiting charge no less than uglenit 10P.
     The deductions were taken out after conducted work.
  1. The new explosive is among to permissible explosive VI classes by safety properties.
  2. The new explosive has positive oxygen balance, that eliminates possibility of formation of burning gases (CO and H2) which are reason the second flame;

     Subsequent work will be directed on determination components ratio optimum of new explosive.
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