DE2202620A1 - Process for the desulphurization of coke by pretreating the coal or coking raw materials - Google Patents

Description

PATENT LAWYER »

. AMTHOK . WOLF

β FBANKFUBT AM MAIN

D-6 FBANKFUHT A. M., 19 1

τ «.. ™» (0611) 55 20 23

11 461

Patronato de Investigacion Cientifica y Tecnica "Juan de

la Cierva "del Consejo Superior de Investigaciones Cientificas,

Serrano, 150 - Madrid-6 / Spain

"Process for the desulfurization of coke by pretreating the coal or coking raw materials"

Sulfur is an undesirable component in coke because of its tendency to migrate into pig iron so that it can be eliminated must in order to prevent the bad properties which it imparts to iron and steel products. This component comes from the coked coal, in which it is found in two forms: as pyrites and as organic sulfur while After coking, pebbles turn into iron sulfide, with about half of the existing sulfur going off, a large one Part of the sulfur, however, is retained by the organic matter in the coal and remains in the coke produced.

Any treatment which diminishes the pyritic sulfur content of coal or diminishes the ability of the coal's organic matter to retain sulfur during its pyrolysis must ₍

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so for the production of coke with a much lower Sulfur content perform as a coke that has not been pretreated Coal or other coking material is obtained. The method according to the invention accordingly relates to the reduction the silica disulfide content as well as the reduction of the reactivity of the organic matter through a pre-oxidation treatment of the starting material.

The method according to the invention is characterized for this purpose in that the material to be coked is either as Raw coal during the *? Settlement process or as already crewash Aqueous solutions of oxidizing reagents, such as hydrogen peroxide, added well in a silo or container with the washing water, Brings nitric acids, nitrates, hypochlorides, permanganates and / or mixtures of these into contact. The nature and concentration of the reagents alone, mixed with one another, or with other reagents used by others Treatments of coal are determined by the silica disulfide content, the distribution of the pebbles in the coal mass, the grain size and the coal quality class.

Said solutions are through a suitable distribution network to the general water flow of the laundry or the silo, which the Contains coal to be treated, added, the concentrations and the duration of treatment in a suitable manner for each case maintained to achieve the desired goal.

The procedure is for coal of any quality class, for mixed

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of coal and mixtures of coal with tars, semi-coke and other products for coke production.

For further explanation, the practical operation is shown below explained.

In a container with a capacity suitable for the tonnage of coal that must be treated in the facility an aqueous solution of the oxidizing reagents or a mixture thereof is prepared. This solution can also Contain other usable reagents intended for other treatments of the charcoal.

If the treatment is carried out in the coal purification plant itself, the said oxidizing solution is added suitable distribution, pumping and metering equipment to the general water flow of the laundry in the appropriate Proportions, depending on the proportions of the coal to be desulfurized.

The contact of the coal with the oxidizing solution becomes a Maintain the necessary amount of time (which can vary between 1 minute and 24 hours) to achieve the desired desulphurisation effect. After this time the coal will be settled from the solution or separated and washed with water to remove the excess of reagents and the through

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the treatment to remove soluble residues. The residue solution is, after previous neutralization, if it has a significant degree of acidity, drained into the drain of the plant. Only in the event that you concentrated very much If solutions of reagents are used, recirculation of this solution should be considered. The charcoal treated in this way is ready for coking.

If the treatment is carried out on coals that have already been cleared the oxidation solution is put into the container, in which the coal to be treated is located. The contact of the coal with the oxidizing liquids is here around the The time (which can vary between 5 minutes and 24 hours) that is necessary to achieve the desired desulfurization effects is increased to reach. The excess of reagents is then removed by washing with water. After this wash the coal is ready for coking.

example 1

The coal to be treated is dry long-flame hard coal in the size of 0.5 to 12 mm, with 37% volatile components and a swelling index in the crucible of 8. It contains 1.41% total sulfur, about half of which is pyrites (o, 75%) is. The coke obtained with this coal contains 1.32% sulfur.

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Treatment was with 40% nitric acid for one hour carried out, the excess acid being removed by washing with water.

The coal treated in this way contained only 1.12% sulfur and that of The coke obtained from this coal contained 1.03% sulfur.

Example 2

The coal to be treated is a hard coal with 32% volatile Ingredients with a swelling index 7, in grains of 0.5 - Io mm. Their sulfur content is 1.09% and that of The coke obtained from this coal contains 1.04% sulfur.

The treatment was acidified with 10% sodium hypochlorite with hydrochloric acid to pH = 5, carried out for two hours, im This is followed by washing with water to remove the excess of reagents. The sulfur content of the coal treated in this way fell to 0.94% and the coke that was obtained from this coal contained only 0.75% sulfur.

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Claims (5)

PATENTANS FRUITS Process for the desulphurization of coke by pretreating the coal or coking raw materials, characterized in that, that the material to be coked is either used as raw coal during the cleaning process or as already washed Well in a silo or container with the washing water added aqueous solutions of oxidizing reagents, such as Hydrogen peroxide, nitric acids, nitrates, hypochlorides, Bringing permanganates and / or mixtures thereof into contact. 2. The method according to claim 1, characterized in that solutions of the reagents are used in concentrations which can circulate several times until they are completely exhausted in order to treat new amounts of coal. 3. The method according to claims 1 and 2, characterized in that one Bertihrungszeit the coal with the solution between Applies from 5 minutes to 24 hours, depending on the concentration of the solution used and the degree of desulfurization desired. 4. Process according to Claims 1, 2 and 3, characterized in that the treated coal grain sizes of o, 5 to 12 mm, in natural Form or by grinding larger dimensions. 5. The method according to claims 1-4, characterized in that, 209837/0694 - Qr- as soon as the oxidizing effect is achieved, the carbon is deposited and washed with water to remove excess reagents and the resulting soluble residues, where the ash water is drained and the coal is ready for coking 6. Process according to claims 1-5, characterized in that that the solutions used have temperatures between 0 C and 50 ° C. 209837/0694 * S ^ φ