RU2735742C1 - Method for preparation of charge for coking - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy. Described is a method of preparing a charge for coking using an oil sintering component and coal concentrates/coals, in which the oil sintering component used is a product obtained by oxidation of a vacuum residue of tar visbreaking with output of volatile substances in range of 30–70 %, which is added to coal charge at following ratio of components, wt%: oil sintering component – 5–40, coal concentrates/coal – balance.

EFFECT: obtaining charge with improved qualitative characteristics by ash content and strength characteristics.

1 cl, 1 tbl, 6 ex

Description

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

It is known that in order to improve the technological characteristics of the charge, improve the quality of coke, and save scarce grades of coal, it is proposed to use various organic additives, such as solid waste from coke-chemical plants, petroleum coke breeze, non-caking coals, and other additives, while ensuring the strength characteristics of coke and reducing the cost of production.

It is known to use as a sintering additive a plasticizer of by-product coke production in an amount of 0.5-7 wt.% (RU No. 2333236, 10.09.2008), and a bituminous residue of the process of obtaining light fractions of petroleum products with the following characteristics: ash content A ^d not more than 2, five%; volatile yield V ^daf not more than 70%; sulfur content S ^d not more than 5%; swelling not less than 20 mm; Horn index (IR) not less than 10 (RU No. 2418837, 20.05.2011).

A significant disadvantage of using the above inventions is the impossibility of using plastic components in the charge of coke-chemical production due to possible agglomeration of particles and stickiness, the need to reconstruct technological equipment in the coal preparation or coke shops, as well as the possibility of replacing only certain grades of coking coals due to the relatively low level of volatile substances.

It is known to use it as a coking additive in the composition of a charge for coking petroleum coke with a yield of volatile substances in the range of 14-25 wt.% (RU No. 2355729, 20.05.2009).

The disadvantage of this additive is the ability to replace only certain grades of coal due to the relatively low level of volatile substances.

It is also known to use a mixture of petroleum coke in an amount of 1-30 wt.% And oil residues in an amount of 1-30 wt.% In the composition of the charge. The oil residues used are characterized by ash content A ^d not more than 2.5%, volatile matter output V ^daf not more than 90%, sulfur content S ^d not more than 5%, Horn index (IR) not less than 10. Petroleum coke is characterized by ash content A ^d not more than 2.5%, the yield of volatile substances V ^{daf is} not more than 25%, the sulfur content S ^{d is} not more than 5%. (RU No. 2627425, 08.08.2017).

A significant disadvantage of using the above inventions is the need for the reconstruction of technological equipment in coal preparation or coke shops.

It is known to use a product of delayed semi-coking of heavy oil residues with a volatile content of 12 to 28 wt% as an oil additive (RU No. 2411283, 10.02.2011; RU No. 2637965, 08.12.2017).

The disadvantage of the additive according to patents of the Russian Federation No. 2411283, No. 2637965 is the instability of its sintering properties, the insufficient level of coking of the additive and, accordingly, the unstable quality of the resulting metallurgical coke, as well as the lack of a description of clear boundaries for the use of this product in the composition of the charge of coke production, which causes difficulties in assess the influence of the participation of this product on the quality of metallurgical coke.

There is also known a method of obtaining an oil sintering additive in a coal coking charge using as an additive the vacuum residue of the visbreaking process with a softening temperature of KiSh of about 80 ° C (RU No. 2455337, 20.03.2012) or the product of deasphalting of this residue (RU No. 2452760, 10.06. 2012).

The disadvantage of this method according to patent RU 2455337 is that at a softening temperature of 80 ° C, the applied petroleum products will have plasticity, which can lead to adhesion of particles and equipment failure, as well as the lack of information on the range of application of these additives in the composition of the batch of coke production.

Closest to the proposed method is the method (RU No. 2663145, 08/01/2018) for preparing a charge for coking, which consists in mixing an oil sintering additive with low-caking coals of grades KS and / or KSN, and / or KO, and / or TS, and / or OS with the following ratio of components, wt%:

- oil sintering additive (1-30),

- low-caking coals (99-70),

petroleum caking additive is a residual oil refining with the following characteristics:

- ash content A ^d - no more than 2.5%;

- the release of volatile V ^daf - no more than 90%;

- sulfur content S ^d - no more than 5%;

- softening temperature according to CuSh - not less than 40 ° С.

The disadvantage of this invention is the lack of technologies for feeding components in a fluid state into the coal charge and, as a consequence, the impossibility of using the invention on an industrial scale.

The objective of the invention is to develop a method for preparing a charge for coking using an oil sintering component, which makes it possible to expand and reduce the cost of the raw material base of the charge used by using a cheaper sintering component without reducing, as well as improving the quality of the resulting coke, as well as a clear distribution of the range of participation of this product as part of the charge.

An oxidized vacuum residue of tar visbreaking with a softening temperature of 90 to 130 ° C (according to the Ring and Ball method) is used as an oil sintering component, which under normal conditions is a solid brittle substance and which allows obtaining metallurgical coke with improved quality characteristics in terms of ash content and strength characteristics.

The problem is solved by the development of a method for preparing a charge for coking using an oil sintering component, which differs in that the product obtained by oxidizing the vacuum residue of tar visbreaking with a yield of volatile substances in the range of 30-70%, which is introduced into the composition, is used as the oil sintering component. coal charge with the following ratio of components, wt%:

Oil sintering component 5-40 Coal concentrates / coals rest

At the same time, the ash content of metallurgical coke (Ad) significantly decreases, the hot strength (CSR) increases, while the participation is significantly reduced or coals of grades Zh and GZh are removed from the composition of the charge, coals of grades K, KS, OS are reduced.

The supply of the oil sintering component to the charge is carried out according to the standard scheme from the silo in accordance with the predetermined proportion of participation through the dosing device, which ensures uniform supply to the belt conveyor. From the belt conveyor, the oil sintering component is fed to the assembly conveyor and, together with the dosed components, to the hammer crusher, then along the charge feed path to the coal tower.

To test the possibility of partial replacement of coals in the composition of the charge for the proposed additive, experimental work was carried out using the charge with the following ratio of components, wt%:

Oil sintering component 5-40 Coal concentrates / coals rest

Variants of the basic and experimental charges were formed with the introduction of an oil sintering component (КиШ-115 ° С) according to the following scenarios (Table 1):

1) Option 1 - basic charge formed with the participation of coal concentrates;

2) Option 2 - an experimental charge based on the base one with the addition of 5% to the oil sintering component with a softening temperature of 115 ° C with a decrease in grade Zh coal concentrate;

3) Option 3 - an experimental charge based on the base one with the addition of 10% to the oil sintering component with a softening temperature of 115 ° C with a decrease in grade Zh coal concentrate;

4) Option 4 - an experimental charge based on the base one with the addition of 15% to the oil sintering component with a softening temperature of 115 ° C with the complete exclusion of grade Zh coal concentrate and a decrease in grade GZh coal concentrate;

5) Variant 5 - an experimental charge based on the basic one with the introduction of 20% of the oil sintering component with a softening temperature of 115 ° C with the complete exclusion of coal concentrates of grade Zh and GZh;

6) Option 6 - an experimental charge based on the base charge with the addition of 40% to the oil sintering component with the complete exclusion of grade Zh, GZh coal concentrates and a decrease in grade K coal concentrates.

During experiments on the introduction of an oil sintering component in an amount of 5-40%, the following was recorded:

1. Decrease in ash content of the coal charge by 3.6% (from 8.9% to 5.3%), respectively, decrease in coke ash content by 4.8% (from 12.0% to 7.2%),

2. An increase in the sintering properties of the charge in terms of an increase in the thickness of the plastic layer (there was an increase of 2-3 mm relative to the base charge), expansion of the plasticity interval by 24-63 degrees. C (when testing dilatometric indicators according to Odiber-Arn). It should be noted that, starting with the version containing 15% NSC, the method for assessing the sintering properties of the charge by the thickness of the plastic layer becomes inapplicable (there is no natural tendency of change).

3. An increase in the values of the hot strength (CSR) of coke (by 0.8-3.3%) and a decrease in the reactivity (CRI) of coke (by 0.4-2.6%).

Thus, in the course of the experiments, the possibility of using an oil sintering component with a volatile matter yield in the range of 30-70% as a substitute for sintering and lean components of coal charges was proved, with the production of metallurgical coke with improved quality characteristics in terms of ash content and strength characteristics.

Claims (2)

A method of preparing a charge for coking using an oil sintering component and coal concentrates / coals, characterized in that the oil sintering component is a product obtained by oxidizing the vacuum residue of tar visbreaking with a volatile matter yield in the range of 30-70%, which is added to the composition coal charge with the following ratio of components, wt%: Oil sintering component 5-40 Coal concentrates / coals rest