Vol 60, No 12 (2017)

The clinkering, coking, and lean components of the coking batch at AO EVRAZ NTMK are experimentally studied. On the basis of the laboratory coking of 67 versions of the production batch at AO EVRAZ NTMK, with different content and properties of the clinkering, coking, and lean components, the formation of the coke’s CSR and CRI values is analyzed. A mathematical model is developed for predicting the coke quality on the basis of the batch characteristics. The pulverized-coal consumption at the blast furnaces is predicted for wet- and dry-quenched coke produced from different batches at AO EVRAZ NTMK.

Laboratory and industrial research confirms that decrease in the clinkering properties of bituminous coal when it is present to excess in the coking batch improves the strength of blast-furnace coke. If coal batch containing >70% bituminous coal is crushed until its content of the ≤3 mm class is 90%, the crushability Π₂₅ may be increased by 1.8%, with decrease in the susceptibility to wear И₁₀ by 0.8%. This behavior may be explained in that increase in the specific surface of the coal particles reduces the fluidity of the plastic mass and hence increases its viscosity. Consequently, the residence time of the gaseous products in the plastic zone increases. That results in the formation of a large quantity high-molecular gas, creating higher expansion pressure. The overall outcome is greater utilization of the destruction products as plasticizers; the formation of additional liquid from the gaseous products within the grains; and improvement in the contact conditions.

Solid, liquid, and gaseous products of the pyrolytic decomposition of coal are studied. Analysis of the gas composition shows that most gas is formed at 600–900°C. The calorific value of the gas is greatest at 500°C, on account of the high concentration of methane and heavy hydrocarbons. The results for the liquid products show that, with increase in temperature, the yield of phenols decreases, while the concentration of polycyclic aromatic hydrocarbons increases.

The yield of tar and its properties in the coking of rammed batch is of particular interest in the light of the broader adoption of this technology. In laboratory reactors, the tar yield from rammed batch is lower than for unrammed batch. However, in industrial furnaces, the tar obtained in the coking of rammed batch is characterized by lower levels of pyrolysis. It is evident from analysis of the tar’s quality, viscosity, and group composition and also from granulometric analysis of the quinoline-insoluble components that the primary destruction products of the thermochemical processes in the coking of rammed batch react with the solid and liquid phases.

The design of production systems at chemical plants is considered. Attention focuses on the selection of the target transformations of materials within a virtual system. The information approach is adopted in an algorithm for step-by-step selection of the target processes and their optimal integration within the virtual system. The key feature of this algorithm is that it allows to use general principles for the distribution of the system’s functions between its elements and subsystems to ensure optimal integration of the target processes. Those principles were described in previous works. As an example, the algorithm is employed in the optimal organization of a system for converting lignite to synthesis gas, with specified proportions of the key components.

@Abstraction limits of flame propagation are determined for 13 glycols, as well as their enthalpy of formation and enthalpy of combustion. These characteristics depend on the number of carbon atoms in the glycol molecule. The combustion parameters are calculated for vapor–air mixtures of glycols and monoatomic alcohols, in the case where P = 1 atm and V = const. The adiabatic combustion temperature of mixtures of limiting and stoichiometric composition does not depend on the number of hydroxyl groups in the alcohol molecule. The explosive pressure of glycol is slightly higher than for monoatomic alcohols.