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Abstract

Content

Introduction

In the early of 1990s Ukraine had developed industries such as mining, coal, aggregates, iron and steel. Every year 240–260 tonnes of industrial explosives had used annually. However, due to the significant, especially over the past 15 years, the decline in coal production and mining industries, the volume of blasting works fell sharply. In 1998 we used only 145 tonness of explosives. However, statistics shows that Ukraine, as before, ranks second in Europe for using explosives. At the same time almost the entire volume of blasting in Ukraine is carried out using explosives containing trinitrotoluol [1]. For the conduct of blasting this explosives are prohibited almost everywhere due to the toxicity of both the trinitrotoluol and its detonation products (NOx, CO).

For implementation of emulsion explosives Ukraine lags behind most of the CIS countries – such as Russia, Uzbekistan, Kazakhstan, Kyrgyzstan [2]. Thus, the inhabitants of mining regions of Ukraine continue to have an additional environmental burden. Today there is a need to create environmentally friendly explosives with low sensitivity to mechanical stress. These may be emulsion explosive.

Advantages of emulsion explosives over the explosives containing trinitrotoluol are:

1. Theme urgency

Production of explosives based on the emulsion matrix directly in mining enterprises and their use is a priority in the development of mineral resources with the use of explosive technologies. Therefore, efforts aimed at improving the technology of manufacturing of explosives up to date.

2. Goal and tasks of the research

The purpose of research – determining the optimal composition of the emulsion for emulsion explosive.

Main tasks of the research:

  1. consider the general concepts of emulsions, their types and receiving;
  2. identify the factors affecting the quality of the emulsion;
  3. consider the characteristics of the components that make up the emulsion;
  4. develop a plant for manufacturing of emulsions;
  5. determine the time of emulsification, depending on the amount of an emulsifier;
  6. study the emulsion obtained with a microscope;
  7. select the optimal content and composition of the emulsifier.

3. The object of the research

The object of this study is an emulsion, which is based on the explosive.

4. Novelty of work

Scientific novelty lies in determining the dependence of emulsion quality and time of its formation on the composition and amount of emulsifier.

5. The practical importance of results

The result of an improved composition of the emulsion for emulsion explosive that will reduce the cost of the final product, to improve the existing production technology.

6. Experimental part

6.1 Experiment

For the preparation of the emulsion have used such devices and materials: mixing Blender, electric household oven, thermometer, scales technical with a set of weights, chemical glasses (volume 150, 200, 300, 1000 ml), a stopwatch, distilled water, ammonium nitrate GOST 2-85, industrial oil GOST 20-799, emulsifier Lubrizol N 7511903-631. The components for the preparation of the emulsion are shown in the picture 1.

Components, included in the emulsion for the production of emulsion explosives

Picture 1 – Components, included in the emulsion for the production of emulsion explosives

The compositions of emulsions are presented in table 1, provided that the weight of finished emulsion is 1 kg.

Table 1 – Component composition of fuel phase
Index number Component
Industrial oilLubrizol
%g%g
13.5352.525
24.0402.020
34.5451.515
45.0501.010
55.5550.55
65.7570.33
75.8580.22

The experiment was performed three times.

The dissolution of ammonium nitrate in water is as follows: 150 g of water was dissolved 790 g of ammonium nitrate with constant stirring and heating the solution at 90–95 °C.

Apart there is a mixture of industrial oil with Lubrizol according to table 1. With heating the solution at 80–85 °C. Mixing time is 5 minutes.

Then the two solutions are mixed in a blender, and a time of emulsify determine by a stopwatch. Depending on the amount of emulsifier is changed during emulsification (table 2).

Table 2 – Time of emulsification with varying amounts of emulsifier
Index numberLubrizol, %The time of emulsify, minute
12.56.59
22.07.15
31.57.36
41.08.17
50.59.59
60.310.38
70.2The emulsion has turned out

Graphic dependence of the time of emulsification of the emulsifier content is presented in picture 2.

Effect of emulsifier content at the time of emulsification

Picture 2 – Effect of emulsifier content at the time of emulsification

Received emulsions were studied under a microscope at a magnification of 400 times with fixation of the particle size of emulsions by measuring the scale of the microscope. The average particle size of emulsions with different amount of emulsifier is shown in table 3.

When the concentration of emulsifier 2.5 % emulsion of the most highly dispersed (average particle size of the emulsion is 1 micron).

Table 3 – Average particle size of emulsions with different emulsifier content
Lubrizol, %The average particle size of emulsion, microns
2.51
2.02
1.53-6
1.05-9
0.515
0.318
0.2–

Graphic dependence of the mean particle size of emulsion on the content of the emulsifier is shown in picture 3.

Effect of emulsifier content on the average particle size of emulsion

Picture 3 – Effect of emulsifier content on the average particle size of emulsion

Type of emulsion "water in oil" under the microscope at a magnification of 400 times, depending on the content of the emulsifier is shown in picture 4.

Type of emulsion "water in oil" depending on the content of the emulsifier: а) 2%; б) 2,5%; в)1,5%; г) 1%; д) 0,5%; е) 0,3%.

Picture 4 – Type of emulsion water in oil depending on the content of the emulsifier: а) 2 %; б) 2,5 %; в)1,5 %; г) 1 %; д) 0,5 %; е) 0,3 %.

When the concentration of emulsifier 2.5 % emulsion of the most highly dispersed (average particle size of the emulsion is 1 micron). With decreasing particle size of its content increases and reaches 18 microns.

6.2 Correlation analysis

Correlation analysis is a statistical study (stochastic) dependence between random variables.

Mathematical measure of the correlation of two random variables is the ratio of the correlation, or correlation coefficient.

Some types of correlation coefficients can be positive or negative (also possible that the lack of statistical relationship – for example, for independent random variables).

The correlation coefficients vary from –1.00 to +1.00. The value of –1.00 means that the variables are negatively correlated. The value of +1.00 means that the variables have a clear positive correlation. A value of 0.00 indicates no correlation [9].

With Microsoft Office Excel entered the data on the time of emulsification results of experiments of table 2. For each value of the content of the emulsifier at the 3 values. It is identified the trend line equation of the line, correlation coefficient (Figure 5).

Dependence is logarithmic.

The correlation coefficient is 0.9816, which indicates a strong connection.

Dependence of emulsifier content at the time of emulsification for the three parallel experiments

Picture 5 – Dependence of emulsifier content at the time of emulsification for the three parallel experiments

7. Existing results

  1. We selected Lubrizol and determined the effect of his detention at the time of emulsification and the average particle size emulsion.
  2. Developed a system for emulsification.
  3. We obtain an emulsion with different emulsifier content, and depending on it, determined the time of emulsification.
  4. Determined the average particle size of emulsions prepared using the measuring scale of the microscope. By the time of emulsification (7.15 and 7.36 minutes when the content of emulsifier 2 and 1.5 % respectively), as well as the average size of emulsion particles (2 microns at 2 % emulsifier), selected the optimal content of the emulsifier, which is 1.8–2 2 %.
  5. The reliability of the results estimated by finding the correlation coefficient, which is 0.9816. This indicates a strong link between the findings of parallel experiments.

Further studies will be conducted with other emulsifiers. It is planned to determine the dependence of the quality of the emulsion on the temperature of emulsification. You should also examine its quality over time.

In writing this essay master's work is not yet complete. Final completion will be in December 2012. Full text of materiallov on the subject may be obtained from the author or his head after that date.

Literature

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