RU2663145C1 - Method for preparing a charge for coking - Google Patents

Abstract

FIELD: metallurgy.SUBSTANCE: invention relates to the field of metallurgy and can be used at coke-chemical plants for the formation of coal charge. To prepare the charge for coking with allowing to receive a product ready for coking, the following components are mixed at a ratio, by mass%: petroleum sintering additive (1–30); coals of KS, and / or KSN, and / or KO, and / or TS, and / or OS (99–70) ranks. Product is obtained in the form of a single-component burden or as a part of a burden mix containing several components. Oil sintering additive is the remains of oil refining with the following characteristics: ash content A– no more than 2.5 %; volatile-matter content V– no more than 90 %; sulfur content S– no more than 5 %; softening point by ring-and-ball procedure – not less than 40 °C.EFFECT: improving the quality of coke, containing low-caking coals, utilization of low-caking coals are provided.1 cl, 6 tbl

Description

The invention relates to the field of production of metallurgical coke and can be used at coke plants for the formation of a coal charge.

Known methods of preparing the charge for coking, in which they mix coking and sintering oil additives with other components of the charge.

A known method of preparing a charge for coking from RF patent No. 2411283 for an invention in which coals of various grades are mixed with an additive that is a product of delayed semi-coking of heavy oil residues with a volatile content of 12 to 25% and a plasticity temperature range of at least 120 ° C. The result is an improvement in the quality of coke due to the fact that due to the wide temperature range of plasticity of the charge begins to compact at lower temperatures and is in a plastic state in a very wide temperature range.

A known method of preparing a charge for coking from RF patent No. 2418837 for an invention in which a charge for coking is obtained by mixing coking coals with a sintering additive, which is a bituminous residue of the process of obtaining light fractions of oil products with the following characteristics:

- ash A ^d not more than 2.5%;

- yield of volatile V ^daf not more than 70%;

- sulfur content S ^d not more than 5%;

- expansion at least 20 mm;

- Horn index (IR) of at least 10.

A disadvantage of the known methods is that oil additives are mixed simultaneously with all components of the coal charge and create conditions for local over-fattening of the sintering components of the charge. Degreasing individual components of the charge causes an increase in porosity and a decrease in the density of a piece of coke, creates a violation of the microstructure of coke, worsening its strength properties.

The method of preparing the charge for coking, known from the patent of the Russian Federation No. 2418837, is selected as the closest analogue (prototype).

The technical problem solved by the present invention is the expansion of the arsenal of methods for preparing the charge for coking.

The technical result achieved by the present invention is improving the quality of coke containing low-sintering coals, utilization of low-sintering coals of grades (KS - coking low-sintering coals; KSN - low-sintering coke coals; KO - coking lean coals; OS - lean sintering coals; TS - lean sintering coals).

The claimed technical result is achieved due to the fact that in the method of preparing the charge for coking with obtaining a product ready for coking in the form of a charge or as part of a charge containing several components, which consists in mixing an oil sintering additive with low-sintering coals of the KS, and / or KSN grades , and / or KO, and / or TS, and / or OS, mixing is carried out in the following ratio of components, mass. %:

- oil sintering additive (1-30),

- coals of KS, and / or KSN, and / or KO, and / or TS, and / or OS grades (99-70),

while the oil sintering additive is the remains of oil refining with the following characteristics:

- ash A ^d - not more than 2.5%;

- yield of volatile V ^daf - not more than 90%;

- sulfur content S ^d - not more than 5%;

- softening temperature according to KiSh - not less than 40 ° C.

Currently, there is a shortage of K (coking coal), L (fatty coal) and KZh (coke-fatty coal) coals in the Russian coking coal market in Russia due to depletion of their reserves.

Note: in this application, coal classification by grades is carried out in accordance with GOST 25543-2013.

According to the claimed method, the oil sintering additive is mixed directly with low-sintering coals of the grades KS, KSN, KO, TS and OS. This does not allow “refining” the charge for coking and, depending on the amount and type of sintering additive, allows to selectively improve the properties of a particular weakly sintering coal and modify it into coke group coals - K, Zh or KZh coals. Then the obtained coke coals are added to the coal charge in the usual way or used to produce metallurgical coke without mixing with other brands of coal (“mono-charge”).

The inventive method provides:

1) an increase in indicators characterizing the sintering and coking properties of coals (indicators of technical, plastometric and reflectogram analyzes);

2) increasing the variability of the set of components of the coal charge;

3) improving the quality of the obtained coke using modified coal in terms of CSR (post-reaction strength) and A ^d (ash).

Oil sintering additives suitable for the implementation of this method are non-digestible residues formed during atmospheric vacuum refining of oil and in thermocatalytic oil refining processes. These include visbreaking residues, tar, asphalt and other products with the following characteristics:

- ash A ^d - not more than 2.5%;

- yield of volatile V ^daf - not more than 90%;

- sulfur content S ^d - not more than 5%;

- softening temperature according to KiSh - not less than 40 ° C.

KiSH - “Ring and Ball” method - a method for determining the softening temperature of oil bitumen from a ring and a ball. The essence of the method is to determine the temperature at which the bitumen located in the ring of a given size softens under the test conditions and, moving under the action of a steel ball, touches the lower plate - at this moment the softening temperature is fixed. The method is important for determining the physicochemical properties of grades of bitumen (GOST 11506-73).

The amount of sintering oil additive in a coal charge, consisting of low-sintering coals of KS, and / or KSN, and / or KO, and / or TS, and / or OS grades varies from 1 to 30%. Adding more than 30% of oil sintering additive to a coal charge is impractical due to the overfat of coal and the deterioration of the quality of the obtained coke in terms of CRI (reactivity) and sulfur content, which reduces the participation rate or completely eliminates the use of such modified coal as a component of the charge for coking.

Examples of the method

Coals of grades were taken: KS (Mezhdurechenskaya concentrator), KSN (Chernigovets open pit), KO (Bachatskaya concentrator), TS (Sibirginsky open pit), OS (Neryungrinsk enrichment factory) and oil sintering additives (DM) with the following characteristics:

- ash A ^d - not more than 2.5%;

- yield of volatile V ^daf - not more than 90%;

- sulfur content S ^d - not more than 5%;

representing the remains of the visbreaking process, deasphalting asphalts and tar with different softening temperatures of 40, 50, 65, 85 and 115 ° C.

Before mixing with oil sintering additives (DM), coal was refined to a particle size of 85% of class 0-3 mm. The temperature of the coal was constant: 20 ° C.

LEDs were added to coal both in crushed form at room temperature, and warmed to a fluid state. Mixing diabetes with coal was carried out in a rotary laboratory mixer for 5 minutes. There were no differences in the plastic properties of the modified coal depending on the temperature and type of DM fed to the mixing, therefore, these indicators are not reflected in the tables.

Determination of the thickness of the plastic layer (Y) of the source and modified coal was carried out in an automated Sapozhnikov apparatus according to GOST 1186-2014.

When mixing DM with coal, both an increase in the yield of the volatile mixture and an increase to a certain limit of the thickness of the plastic layer (Y, mm) occur. Given these parameters, the grade of the obtained modified coal is determined.

The dependence of the thickness of the plastic layer (Y, mm) and the grade of the obtained modified coal on the softening temperature according to Ki and the amount of LED added to the coal are given in tables 1-5.

With an increase in the proportion of oil sintering additive in a mixture with coal, the thickness of the plastic layer of modified coal increases, however, adding more than 30% DM to coal is impractical due to the deterioration in the quality of the obtained coke in terms of CRI (reactivity) and sulfur content.

With an increase in the softening temperature of DM, the plastic properties of all types of coals studied improve. The use of SD to modify coal with a softening temperature below 40 ° C is impractical due to the reduction of the effect of improving the plastic properties and the appearance of signs of caking of coal, which makes it impossible to store it in a stack.

To confirm the qualitative characteristics of the modified coal, selective laboratory coking was carried out in accordance with GOST 9521 with the determination of the reactivity and post-reaction strength of CRI and CSR coke according to GOST R 54250-2010.

The quality of coke obtained by coking of modified coal (Bachatskaya concentrator and Mezhdurechenskaya concentrator) is shown in table 6.

The quality of coke obtained from modified coal confirms its compliance with the brand, determined by the size of the plastic layer.

With an increase in the proportion of DM in a mixture with coal, the quality of the obtained coke improves. Moreover, after reaching the maximum value for a certain proportion of DM in the coal for a mixture, a decrease in the quality characteristics occurs, which is associated, first of all, with the overfat of coal.

Thus, by mixing low-sintering coals of KS, KSN, KO, TS and OS grades with an oil sintering additive with the characteristics specified in the application, coking coal grades of K, G and KZh grades are obtained, which can then be used as a component in a coal charge for coking , or the obtained modified coals can be used to produce metallurgical coke without mixing with other brands of coal.

Claims (8)

A method of preparing a charge for coking with obtaining a product ready for coking in the form of a mono-charge or as part of a charge containing several components, which consists in mixing an oil sintering additive with low-sintering coals of the KS, and / or KOS, and / or KO, and / or TS , and / or OS in the following ratio of components, mass. %: - oil sintering additive (1-30), - coals of KS, and / or KSN, and / or KO, and / or TS, and / or OS grades (99-70), while the oil sintering additive is the remains of oil refining with the following characteristics: - ash A ^d - not more than 2.5%; - yield of volatile V ^daf - not more than 90%; - sulfur content S ^d - not more than 5%; - softening temperature according to KiSh - not less than 40 ° C.