DETERMINATION OF THE INFLUENCE OF COMPOSITION MODIFIERS BASED ON SECONDARY POLYMER MATERIALS ON THE CORROSION OF THE PIPELINE SYSTEM

ABSTRACT

In the article, the problems of the pipeline system used in the transportation of beneficiation residues in the state of hydromixing in the mining industry, copper beneficiation factory are studied. The parameters of the flow affecting the production of pipes are defined. The influence of the modification of dispersed systems in the hydraulic mixture on the pipe wall was studied, while studying the methods of improving the characteristics of the flow parameters, reducing the production of the pipeline system, and increasing the service life and efficiency. The flow of dispersed system hydromix without modifier and with modified condition was studied in reducing pipe construction. As a result of the conducted research, it was possible to increase the service life of the pipe by 29% and 31%, respectively, by the mass and thickness, and the overall average efficiency of the pipe by 30%.

АННОТАЦИЯ

В статье изучены проблемы трубопроводной системы, используемой при транспортировке остатков обогащения в состоянии гидросмешивания в горнодобывающей промышленности, меднообогащающем комбинате. Определены параметры потока, влияющие на производство труб. Изучено влияние модификации дисперсных систем в гидравлической смеси на стенки трубы при изучении методов улучшения характеристик параметров потока, снижения производительности трубопроводной системы, увеличения срока службы и эффективности. Исследовано течение гидросмеси дисперсной системы без модификатора и в модифицированном состоянии в конструкции редукционной трубы. В результате проведенных исследований удалось увеличить срок службы трубы на 29% и 31% соответственно по массе и толщине, а общий средний КПД трубы - на 30%.

Keywords: hydromix, dispersed system, composite modifier, pipe, dissolution, hydrotransport.

Ключевые слова: гидроcмес, дисперсная система, композиционный модификатор, труба, растворение, гидротранспорт.

Introduction. Today, in the mining industry, hydrotransport systems are used to transport waste from the enrichment plant in a hydromixed state [1, 2, 3]. It remains an urgent issue to reduce the wear and tear of the hydrotransport systems in use, to increase the service life and efficiency [2, 3]. The stress on the pipe walls during the flow of the coarse dispersed systems in the hydraulic mixtures, the formation of hydraulic resistance due to the friction of the dispersed systems, and the corrosion problems caused by the elements contained in the hydraulic mixture are considered to be the branches for solving the problem. The construction of pipe walls leads to an increase in operating costs. One of the most important tasks to increase the service life and efficiency of pipelines, to reduce the friction and wear of dispersed systems in the hydraulic mixture is to reduce the effect on the pipe during the flow of the hydraulic mixture [1, 5].

In the article, the use of the method of modifying the dispersed systems in the hydromix with composite compounds is recommended as a modifier of the composite compound based on secondary organic materials.

Research object and method. As a research object, a system of pipes used in the transportation of waste from a mining industry copper beneficiation plant was taken. In order to increase the stability of the pipelines, prolong their service life and increase their efficiency, the indicators of the pipeline system were studied based on GOST 9.908-85 and GOST 10704-76. For the modification of dispersed systems, we used a composite compound based on secondary organic materials as a modifier.

Research results  and discussion. Pipe production was studied on the basis of pipes with D=720 mm and thickness of 12 mm in our facility. 1.5 m steel pipes with a weight of 6,435 kg D=50 mm and a thickness of 3,8 mm were used to determine the yield. The test process was carried out in 2 stages, in the 1st stage we measured the actual weight of the pipe  (the actual weight was 6,435 kg), prepared a hydromix with a concentration of 25% from waste slag from the 2-MBF and observed its movement in the pipe for 8 hours. Then the pipe was removed and re-measured, and the volume was determined in mass units based on the formula (1-5):

  kg/m²                                    (1)

Here  – the weight of the sample before the test, kg;  – sample weight after testing, kg;   – surface of the sample, m².

Also, the share of production as a result of hydromix movement was as follows:

                                  (2)

The maximum deflection of a pipe with D=50 mm is allowed up to 42% of the total weight, therefore, if we calculate the service life:

     , day                              (3)

In the experimental test, taking into account the dimensions of the sample, the change in thickness of the sample due to mass loss,  mm, was calculated as follows:

       , mm                                       (4)

Here   – mass loss per area units of the sample, kg/m²;

 – the density of the pipe material kg/m³.

The thickness of our chosen pipe is 3,8 mm, the limit yield thickness is 1,2 mm, and the average service life up to the limit yield thickness was as follows:

 ,  day                                 (5)

Secondary organic substances - gossypol tar, carboxymethylcellulose, secondary adsorbents (Alkanolamines) produced as a result of natural gas processing were used in the preparation of the composite compound for use as a modifier [6, 7].

We added the prepared composite compound to the hydraulic mixture at a ratio of 80 g/t and observed the behavior of the modified hydraulic mixture in the pipe. Based on the conducted studies, the influence of the dispersed systems in the hydraulic mixture on the pipe parameters and the changes in the parameters after the modification of the dispersed systems were calculated.

We mentioned above that the dispersed systems in the hydraulic mixture moving in the pipe rub against the pipe walls during the flow. The weight of the pipe is lost per unit of surface area as a result of friction. We determined the loss of pipe weight per surface area under the influence of dispersed systems for 8 hours in laboratory conditions, and to reduce it, we modified the dispersed systems using composite compounds prepared on the basis of local raw materials, and we observed the behavior of the hydromix with the modified dispersed system in the pipe again for 8 hours. Based on the experiments, we found that the effect of the dispersed systems modified with the composite compound on the pipe wall was reduced by 31% in the case of kg/m² (Fig. 1).

Figure 1. To reduce the weight-to-surface ratio of piping: 1- situation before the modification of dispersed systems moving in the  pipeline; 2 - state after modification

During the use of the pipeline system, its weight is reduced to a certain extent due to wear, therefore, in the pipe system of all diameters, there is a limit percentage indicator of the weight of the pipe in use, therefore, in our research work, we conducted laboratory studies to reduce the percentage of wear, the test time is 8 hours, the duration of repetition is 2 times did by modifying the dispersed systems in the hydraulic mixture with the help of a composite compound, we achieved a 31% reduction in the percentage of pipe failure (Fig. 2).

Figure 2. Reducing the fraction of the pipe by weight: 1- situation before the modification of dispersed systems moving in the pipeline; 2 - state after modification

It is important to increase the service life of the pipeline system in order to improve its efficiency. In our research work, increasing the service life of pipes was carried out according to 2 parameters - pipe mass and thickness. By modifying the dispersed systems in the hydraulic mixture moving in the pipeline with composite compounds, we proved that it is possible to increase the service life of the pipeline by 29% up to the permissible percentage by mass (Fig. 3).

Figure 3. Increasing the service life of the pipe by weight: 1- situation before the modification of dispersed systems moving in the pipeline; 2 - state after modification

The second parameter is the reduction of influence on the pipe walls of the dispersed systems modified by the composite compound prepared from local raw materials in increasing the service life of the pipe thickness. We proved in laboratory conditions that the service life of the pipe is increased by 31% according to the permissible thickness (Fig. 4).

Figure 4. Increasing the efficiency of use by the thickness of the pipe:
1-situation before the modification of dispersed systems moving in the 1st pipeline; 2-state after modification

Studies conducted in the course of studying the effect of compositional modifiers on the performance of piping systems have proven their effectiveness.

Conclusion. During the research, we determined the factors affecting the performance of the pipeline system, we prepared a composite compound that improves the characteristics of these factors, reduces the performance of the pipeline system, and increases the service life and efficiency. We studied their effect on the pipe wall by modifying the dispersed systems with a composite compound prepared on the basis of secondary organic materials. As a result of the conducted research, the service life of the pipe mass and thickness increased by 29% and 31%, respectively, and the overall average service efficiency of the pipe increased by 30%.

References:

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