Predicting the yield of coking byproducts on the basis of elementary and petrographic analysis of the coal batch

Mathematical models are developed for predicting the yield of coking byproducts on the basis of elementary and petrographic analysis of the coal batch.     

Preliminary estimation of coke’s CRI and CSR values on the basis of the physical properties of coal ash

The relation between the physical properties of coal ash and the CRI and CSR values of coke is established. It is suggested that increase in the mean molecular mass of coal ash increases the reactivity and disintegration of coke pieces in tests according to the ISO 18894:2006 (E) standard.     

Influence of the coking properties of coal batch on coke properties

At OAO Zapadno-Sibirskii Metallurgicheskii Kombinat (ZSMK), research is undertaken to improve the optimization of coking batch. The basic approach, proposed by specialists from OAO Nizhne-tagil’skii Metallurgicheskii Kombinat, employs the coefficient K _opt, which characterizes the deviation of the batch from its optimal composition. The coking properties of the OAO ZSMK coal batch over the last few years are analyzed. After laboratory and industrial coking of batch with different K _opt, the strength and reactivity of the resulting coke is investigated. Evaluation of coke-grade coal in terms of its rank according to State Standard GOST 25543-88 proves inadequate, since coal of the same rank may differ markedly in coking properties. A method is established for assessing the optimality of the coal batch at OAO ZSMK.     

Influence of coal preparation and coking conditions on coke reactivity

The influence of various technological factors on the high-temperature properties of coke is investigated. It is found that factors facilitating an orderly organic structure of the coke (fine grinding and compaction of the batch, increased conditioning of the coke, dry slaking, the introduction of lubricant additives in the batch) reduce the reactivity of the coke; by contrast, introducing coke fines, intermediate product, and red mud in the batch increases the reactivity.     

Predicting the coke yield on the basis of the yield of coking products

The characteristics of Kuznetsk Basin coal concentrates and their yield of coking products are determined. On that basis, experimental coal blends are formulated and analyzed.     

Predicting the yield of coke and its byproducts on the basis of elementary and petrographic analysis

It is established that the yield of coke and its primary byproducts may be predicted on the basis of elementary and petrographic analysis of the coal (batch) employed. The contribution of individual groups of petrographic components in the coal to the yield of coke and its primary byproducts is determined; coal from the Ukraine, Russia, and the United States is considered. The method developed for predicting the yield of coke and its primary byproducts on the basis of petrographic data is tested at PAO Alchevskkoks and ChAO Makeevkoks.     

Influence of batch properties and its preparation and coking conditions on the characteristics of coke

The influence of batch preparation on the properties of blast-furnace coke is considered for OAO Zapadno-Sibirskii Metallurgicheskii Kombinat. In particular, the influence of the batch composition and its preparation and heating conditions on the strength of blast-furnace coke is investigated. It is found that increasing the moisture content of the batch from 7.3 to 12.6% impairs coke strength: M ₁₀ changes from 7.8 to 9.4%. The mechanical strength is also reduced by increasing the ash content and reducing the piece size of K, OS, and KS coal.     

Influence of the high content of Zh coal in coking batch on the coke quality

Industrial tests show that the enrichment of coal batch containing more than 70% Zh coal must be increased in order to boost coke strength. However, it makes more sense to replace some of the Zh coal in the batch with an optimal quantity of G coal, and to reduce the degree of crushing, so as to ensure coke quality consistent with blast-furnace requirements (minimum strength M ₂₅ = 90%, M ₁₀ = 6%).     

Influence of petroleum coking additive on the quality of coal batch,coke, and tar

Given the shortage of coal with good coking properties, a petroleum coking additive is introduced in coal batch so as to expand the range of plasticity. This additive improves coke quality in every respect, except the total sulfur content. Measures to reduce the additive’s negative impact on the coal pitch are considered.     

Effect of petrographic property of single coking coal on caking and coking properties

对不同变质程度单种煤的煤岩性质以及对应的40kg试验焦炉所炼焦炭的性质进行测定和分析表明,单种煤的黏结性不仅受煤变质程度影响,而且受炼焦煤中煤岩组成的影响,单种煤的镜质组平均最大反射率在1.1％左右时,煤的黏结性最好;镜质组反射率分布在1.1％～1.3％所占比例为30％左右时,所得焦炭的M40和M10最好.     

单一炼焦煤煤岩性质对黏结性和结焦性的影响

对不同变质程度单种煤的煤岩性质以及对应的40kg试验焦炉所炼焦炭的性质进行测定和分析表明,单种煤的黏结性不仅受煤变质程度影响,而且受炼焦煤中煤岩组成的影响,单种煤的镜质组平均最大反射率在1.1%左右时,煤的黏结性最好;镜质组反射率分布在1.1%~1.3%所占比例为30%左右时,所得焦炭的M40和M10最好。     

Predicting the yield of coke and coking byproducts

The influence of various factors on the gross and metallurgical coke yield and the yield of coking byproducts at OAO Zaporozhkoks is studied. Analysis of laboratory data results in a mathematical formula for the influence of the reflection coefficient of vitrinite and the sum of lean components on the yield of coke and coking byproducts. Conversion factors from the calculated gross coke yield to the actual production yield (when batch preparation and coke-battery design are taken into account) are presented.     

Predicting the carbonizing period and coking heat of coal charges in horizontal-chamber coke ovens

The carbonizing period and coking heat of coal charges in horizontal-chamber coke ovens have been calculated for different variables influencing the carbonization process by applying two Fourier differential equations. The results from these calculations and from numerous tests in commercial coke ovens were analysed by means of statistical methods. Two regression equations were formulated, enabling the carbonizing period and coking heat to be predicted with sufficient precision.     

Particle size and mass of coke samples for determining CRI and CSR

Means of obtaining representative coke samples are considered. The influence of the size class on CRI and CSR is discussed, along with deficiencies of the NSC method.     

Optimizing the coal batch for coking

Optimization of coke production is considered. Mathematical experiment design, which is an active research method, calls for artificial changes in the input parameters. In actual production conditions, active experiments are not possible on account of material and time constraints. These problems may be eliminated on the basis of reserves of production data.     

煤岩分析在焦化企业的应用研究

主要从煤岩分析方法对煤种和混煤鉴定、指导配煤、预测焦炭质量、指导进厂煤合理分堆、测定焦炭光学组织等方面进行阐述。研究表明,煤岩分析镜质组反射率分布图对进厂煤质的鉴定及混煤情况的判别效果明显,可优化配煤方案,改善配煤比,稳定焦炭质量,指导合理堆放煤种。     

Group chemical composition of coal batch and reactivity of coke 1. Determining coke reactivity

With a view to finding correlations between coke reactivity and the coal batch employed, methods of determining coke reactivity are considered—in particular, the standard and pulsed methods. The kinetic equation fundamental to all methods of assessing the coke reactivity from the gasification rate constant is presented. The possibility of combining data obtained by different methods of estimating the coke reactivity is established.     

Changes in the petrographic composition of coal batch on crushing

The influence of crushing on the maceral composition of coal is studied. The experimental data indicate not only redistribution of the petrographic microcomponents by size but also change in the maceral composition, depending on the intensity of grinding. With increase in the degree of crushing from 55.5 to 96.2%, the vitrinite content in the batch declines from 70 to 63%, while the total content of fusinized components increases from 29 to 35%. For coal with 50–80% vitrinite, which is less strong than coal with smaller vitrinite content, crushing is probably accompanied by disruption of the molecular interactions and rupture of the chemical bonds in the organic macromolecules. That leads to partial destruction of the brittle vitrinite structure, especially in the intermediate stages of metamorphism (R _o = 0.9–1.39%).