Mathematical Modeling of Determining the Composition of the Charge in the Cross Section of the Blast Furnace

When working on a multi-component charge, BLT cannot ensure the uniformity of the charge composition in the horizontal section of the blast furnace. In this case, there is a need to develop mathematical models and expiration portions forming material from the hopper to the subsequent creation of BLT software. With reference to the operating conditions of the blast furnaces of JSC ‘EVRAZ NTMK’, mathematical modelswere developed for the formation of materials in the silo hopper by the consecutive unloading of two skips; in the order of emptying the hopper; on the distribution of charge on top throat of the blast furnace. On the basis of combining the developed mathematical models, computer software was created to form portions of chargecomponents, both in the BLT hopper and on the top throat. Created software product for calculating the formation of portions and the expiration of materials from the receiving hopper of the BLT allows you to quickly select the necessary load and optimize the process as a whole. Keywords: blast furnace, burden, charging, bell-less top (BLT), sinter, pellet

Structure and magnetic properties of mechanically alloyed Fe3-xAlCrx powders

Mixtures of elemental powders of Fe3-xAlCrx composition, where x ∈ (0.8 -1.2) were mechanically alloyed in the AGO-2U planetary ball mill. Obtained powders consist of particles with median size of 0.5-1.6 µm; increase in the Cr content results in the decrease in the size of particles. According to the X-ray data, all of the as-milled alloys possess a single-phase disordered b.c.c. structure. Increase in Cr content results in the decrease in the grain size of alloys, whereas the dependence of the lattice parameter on the chemical composition is not conclusive. Mössbauer spectra for most of the alloys shows that iron atoms in this alloys, in spite of the fact that only one phase was detected using the X-ray diffraction, exist both in ferromagnetic and non-ferromagnetic conditions

Improvement in vanadium-containing titanomagnetite processing technology

The article describes the modern technology of iron smelting from vanadium-containing titanomagnetite. The complex of research presented by the NTMK team and the leading research teams of the Ural Institute of metals, the metallurgical Institute of the Ural branch of the Russian Academy of Sciences, and the Ural Federal University is the basis for achieving high productivity of the blast furnaces EVRAZ NTMK. The presented research and development works are the basis for the technology of metallurgical processing of vanadium-containing titanomagnetite. The developed technology makes it possible to achieve high rates of melting intensity and total consumption of carbon contained in the fuel. Such indicators are achieved by reconstruction, namely by changing the line of the working space of the blast furnace. Modern loading devices were used, energy-efficient technology of coal-dust fuel intake was introduced, and the oxygen content in the air was increased. Considerable attention is paid to the analysis of the domain process and problems of domain melting of titanomagnetite. Particular attention is paid to the implementation of measures to reduce the content of titanium in cast iron. © Published under licence by IOP Publishing Ltd

Translational mobility of water molecules and Li+, F-, and Al3+ ions in aqueous solutions of LiCl, KF, and Al(NO3)3

The concentration dependences of the overall self-diffusion coefficients of water molecules, F- and Li+ ions, and [Al3+(H2O)6] hydrated ions measured in aqueous solutions of LiCl, KF, and Al(NO3)3 are discussed. An analysis of the whole set of experimental results shows that translational mobility of water molecules in solutions of electrolytes is largely determined by the degree of hydration of the ions and is virtually independent of their translational mobility; translational mobilities of the ions themselves depend on the structural characteristics of their hydration sheaths and the structure of water around them

Анализ возможных путей снижения содержания серы в чугуне

One of the ways to increase the energy efficiency and intensity of blast furnace smelting, especially when using pulverized coal fuel, is to increase the hot strength of coke. In the conditions of OJSC NLMK, an oil additive was introduced into the coal charge to improve the coke quality. At the same time, sulfur content in the coke increases, and, consequently, sulfur content in the cast iron increases as well. In this regard, the task of finding ways to improve the desulfurization of cast iron in blast furnace becomes urgent. The main factors determining the desulfurization of cast iron are slag basicity, content of MgO oxide in it, temperature of the smelting products, and the slag viscosity. The purpose of this work was to compare the efficiency of sulfur removal by increasing the slag basicity and MgO content. On the basis of well-known equations, an algorithm was developed that allows the problem to be solved. It was established that an increase in MgO content in the slag promotes desulfurization of cast iron to a greater extent than a basicity increase. In addition, an increase in MgO content by 1 % is accompanied by an increase in slag yield by 3.0 – 3.5 kg/t of cast iron. At the same time, an increase in basicity by 0.01 leads to an increase in the slag yield by 4 – 5 kg/t of pig iron. Consequently, reducing the sulfur content in pig iron by increasing the slag basicity requires less heat. In terms of the specific consumption of coke, difference in heat demand is 0.4 – 0.5 kg/t of pig iron. It is shown that with an increase in MgO content in the slag, the slag viscosity at a temperature of 1450 °C increases to a lesser extent than with an increase in basicity. © 2020 National University of Science and Technology MISIS. All rights reserved

TREATMENT OUTCOMES OF COLORECTAL CANCER WITH BILATERAL LIVER METASTASES

The purpose of the research: to develop an effective treatment regimen for patients with synchronous liver metastases from colorectal cancer. Material and methods. The study included 126 patients with colon cancer and synchronous liver metastases. The patients were divided into two groups. Group I consisted of 64 patients, who underwent resection of the colon and hepatic resection with radiofrequency ablation of metastases in the remaining portion of the liver and portal vein chemoembolization. Then, they received 4 courses of systemic chemotherapy followed by hepatic artery chemoembolization. Group II (the control group) consisted of 62 patients, who underwent resection of the colon without hepatic resection. Systemic chemotherapy was administered 3‑4 weeks after resection of the colon. Results. Postoperative complications occurred in 18 (28.1 %) patients of Group I and in 10 (16.1 %) patients of Group II. Six patients died (4 patients in Group I and 2 patients in Group II). Of the 18 postoperative complications occurred in Group I, 9 were related to hepatic resection. The median progression-free survival time was 9.0 months in Group I patients and 5.0 months in Group II patients, p=0.001. The median overall survival time was 13.8 months and 9.8 months in patients of Group I and Group II, respectively (p=0.004). Conclusion. Treatment options used for Group I patients resulted in improved survival rates

Combination of chemoembolization with hepatic resection and methods of local destruction in complex treatment of colorectal cancer

The aim of the study was to prove the efficacy of the treatment regimen for patients with colorectal cancer with metastatic liver involvement. The regimen included a combination of colon and liver resection, methods of local destruction and chemotherapy. There were 126 patients with colon cancer and metastases in the liver involved in the study. All tumors were adenocarcinomas of the intestinal type. Metastases in the liver affected both lobes of the liver. In the main group (64 patients), resection of the large intestine and liver resection were carried out. During the operation, radiofrequency ablation of the remaining metastases and chemoembolization of the portal vein were performed. In the postoperative period, systemic chemotherapy and chemoembolization of the hepatic artery were prescribed. In the control group (62 patients), surgery was performed on the large intestine and systemic chemotherapy was performed. Complications of the operation occurred in 18 patients (28.1 %) in the main group and 10 in patients (16.1 %) in the control group (p = 0.004). Median disease-free survival in the main group was 9.01 months, in the control group - 5.01 months (p = 0.001). Median overall survival in the main group was 13.8 months, in the control group - 9.8 months (p = 0.004). One-year overall survival in the main group was 60.93 %, in the control group - 41.93 %, two-year in the main group -17.18 %, in the control group - 6.45 %. In the control group, there were no three years survivals, and in the main group, the three-year overall survival was 4.68 %

Towards targeted colorectal cancer biopsy based on tissue morphology assessment by compression optical coherence elastography

Identifying the precise topography of cancer for targeted biopsy in colonoscopic examination is a challenge in current diagnostic practice. For the first time we demonstrate the use of compression optical coherence elastography (C-OCE) technology as a new functional OCT modality for differentiating between cancerous and non-cancerous tissues in colon and detecting their morphological features on the basis of measurement of tissue elastic properties. The method uses pre-determined stiffness values (Young’s modulus) to distinguish between different morphological structures of normal (mucosa and submucosa), benign tumor (adenoma) and malignant tumor tissue (including cancer cells, gland-like structures, cribriform gland-like structures, stromal fibers, extracellular mucin). After analyzing in excess of fifty tissue samples, a threshold stiffness value of 520 kPa was suggested above which areas of colorectal cancer were detected invariably. A high Pearson correlation (r =0.98; p <0.05), and a negligible bias (0.22) by good agreement of the segmentation results of C-OCE and histological (reference standard) images was demonstrated, indicating the efficiency of C-OCE to identify the precise localization of colorectal cancer and the possibility to perform targeted biopsy. Furthermore, we demonstrated the ability of C-OCE to differentiate morphological subtypes of colorectal cancer – low-grade and high-grade colorectal adenocarcinomas, mucinous adenocarcinoma, and cribriform patterns. The obtained ex vivo results highlight prospects of C-OCE for high-level colon malignancy detection. The future endoscopic use of C-OCE will allow targeted biopsy sampling and simultaneous rapid analysis of the heterogeneous morphology of colon tumors

РЕЗУЛЬТАТЫ КОМПЛЕКСНОГО ЛЕЧЕНИЯ КОЛОРЕКТАЛЬНОГО РАКА С БИЛАТЕРАЛЬНЫМ МЕТАСТАТИЧЕСКИМ ПОРАЖЕНИЕМ ПЕЧЕНИ

The purpose of the research: to develop an effective treatment regimen for patients with synchronous liver metastases from colorectal cancer. Material and methods. The study included 126 patients with colon cancer and synchronous liver metastases. The patients were divided into two groups. Group I consisted of 64 patients, who underwent resection of the colon and hepatic resection with radiofrequency ablation of metastases in the remaining portion of the liver and portal vein chemoembolization. Then, they received 4 courses of systemic chemotherapy followed by hepatic artery chemoembolization. Group II (the control group) consisted of 62 patients, who underwent resection of the colon without hepatic resection. Systemic chemotherapy was administered 3‑4 weeks after resection of the colon. Results. Postoperative complications occurred in 18 (28.1 %) patients of Group I and in 10 (16.1 %) patients of Group II. Six patients died (4 patients in Group I and 2 patients in Group II). Of the 18 postoperative complications occurred in Group I, 9 were related to hepatic resection. The median progression-free survival time was 9.0 months in Group I patients and 5.0 months in Group II patients, p=0.001. The median overall survival time was 13.8 months and 9.8 months in patients of Group I and Group II, respectively (p=0.004). Conclusion. Treatment options used for Group I patients resulted in improved survival rates.Цель исследования – разработать эффективную схему лечения пациентов с синхронными метастазами в печени при колоректальном раке. Материал и методы. В исследование включено 126 пациентов, страдающих раком толстой кишки с синхронными метастазами в печени. В основную группу вошли 64 пациента, которым проводились резекция толстой кишки и резекция печени с радиочастотной абляцией метастазов в остающейся части печени и химиоэмболизацией воротной вены, потом им назначали 4 курса системной химиотерапии, после которой выполняли химиоэмболизацию печеночной артерии. В контрольную группу вошли 62 пациента, которым выполняли резекцию толстой кишки без вмешательства на печень, а через 3–4 нед начинали системную химиотерапию. результаты. Послеоперационные осложнения возникли у 18 (28,1 %) пациентов основной и 10 (16,1 %) пациентов контрольной группы. В ходе исследования умерло 6 пациентов, из них 4 – в основной группе, 2 – в контрольной. Из 18 послеоперационных осложнений в основной группе 9 были связаны с резекцией печени. Медиана выживаемости без признаков прогрессирования в основной группе составила 9,01 мес, в контрольной группе – 5,01 мес (p=0,001). Медиана общей выживаемости в основной группе составила 13,8 мес, в контрольной группе – 9,8 мес (p=0,004). Заключение. Использованная в основной группе больных схема комплексного лечения позволяет улучшить показатели выживаемости.