SU1586995A1 - Method of producing sulfur dioxide - Google Patents

Abstract

This invention relates to the production of sulfur dioxide from sulfur in the production of sulfuric acid. The purpose of the invention is to increase the purity of sulfur dioxide and reduce the loss of sulfur. Sulfur evaporation in a sulfur burning furnace is carried out by supplying an oxidizing gas to the surface of a sulfur melt mirror with a jet of impact type directed at an angle of 15-45 ° to the melt mirror in the peripheral zone of the mirror 0.10-0.33 wide from its boundary. Ash impurities are continuously removed by a circulating stream of sulfur in the amount of 4-20% of the total amount of initial sulfur, followed by filtration and return of this stream to the sulfur melt layer. 1 hp f-ly, 1 tab.

Description

The invention relates to methods for producing sulfur dioxide from sulfur in the production of sulfuric acid and can be used in the chemical industry and the industry of mineral fertilizers.

The purpose of the invention is to reduce the loss of sulfur from the cake and to reduce the amount of fluff in the target product while maintaining productivity.

The drawing shows a furnace in which the method is carried out.

The method is carried out in the following manner.

The unfiltered liquid sulfur in an amount that ensures the productivity of the system is continuously introduced into the furnace 1 into the sulfur bath 2 located in the lower part of the furnace. The oxidant gas (air) is fed to the furnace

in 3 and For two or more sov. The inclined tuyeres 3 of the lower sulfur gas closest to the mirror are made so that the air flowing out of them tangentially twists, moreover, is directed at an angle of 15-45 ° to the sulfur melt mirror and intersects the plane of the mirror at a distance of 0.17- 0,4D from the center of the furnace. Due to this technique, the air jet striking the surface of the melt partially penetrates into the volume of the melt and foams sulfur, breaks the surface film, which contributes to the burning out of organic impurities that pop up to the surface of the melt. In this case, about 10% of sulfur is oxidized in the volume and surface of the melt of the amount of sulfur burned in the furnace. Air blows vapor from the melt

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The first sulfur that burns in a cyclone: a gas flow in the furnace volume, Quantum, icTBE of vapors of sulfur and jars carried out in the furnace volume and burned-out organic impurities from the surface film largely depend on the point of impact of the air stream into the melt mirror. So the greatest effect is obtained when this meeting point is located at a distance of no more than 0.4D from the center of the furnace, This is due to the fact that in the axial 13on from the melt mirror the capture of 1sulfur vapors is mainly accomplished by 1 account of the suction effect of gas | created in the furnace, in the peripheral part, the vapor is carried into the volume of the furnace by the directional: air stream. In this case, a more uniform heating of the sulfur melt occurs due to partial oxidation of sulfur in the melt, radiation-1 convective heat transfer from the side of the gas stream and a good displacement of the surface layer of the melt. ; - From the lower part of the furnace, through sulfur 4, a stream of sulfur with ash is removed: With impurities and solid bitumen components: in the amount of 4-20% of the total I amount of loaded sulfur, which: is sent to the collection 5 - ry, from where, the pump is fed to the filter 6, the ash impurities from the filter are sent to the dump, and the stream of filtered sulfur 7 together with the stream of initial sulfur 8 is fed to the furnace to the sulfur melt mirror.

The slope of the jet of oxidizing gas (air) to the surface of the sulfur layer is selected in the range of 15-45. With a smaller angle of inclination (opt-5) and an increase in the angle of inclination (experiment 6), the hydrodynamics of the movement of the mirror of the sulfur layer deteriorates, the organic impurities are not completely removed from the surface of sulfur, which delays the process of sulfur oxidation. At the same time, the evaporation rate decreases, the productivity of the apparatus decreases, the gas is used up; it grows due to local discharges when the precipitating ash is agitated and brought into the superlayer space.

The amount of circulating sulfur

Provision of ash removal of impurities from the furnace, in the pre, 4-5% of sarpy raw material (experiments 2, 3, 4, 8). When this is achieved, the reduction of the dust content of sulfur dioxide is 2.5-7.14 times without

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55

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35

40

45

50

speeds of sulfur evaporation. By reducing the amount of recycled sulfur stream (experiment 7), the viscosity of the polluted sulfur stream increases, which makes it difficult to pump, filter, in addition, reduces the productivity of the apparatus and increases the dust content of the gas. With an increase in sulfur retour (op-9), material and energy costs increase due to an increase in the amount of sulfur supplied for filtration.

The axis of the gas of the oxidizing gas should pass through the plane of the peripheral zone of the melt mirror at a distance of 0.17-0.40 from the center of the furnace. In this case, the fullest evaporation and burning of sulfur occurs, which is explained by the rise of vapors in the gas phase due to the cyclonic effect. When the axis of the directed jet of oxidant gas is removed from the proposed distance interval (experiments 11, 12), the evaporation rate deteriorates and the specified performance is not achieved.

Indicators of the method for producing sulfur dioxide are given in the table.

Example. 2500 kilograms per hour of molten sulfur are supplied to the sulfur burning furnace with a liquid bath, and 100 kg / h of pure sulfur are fed. The proportion of filtered sulfur is 4%. The content of impurities in sulfur is%: dirty: ash 0 , 2, organic 0.03, filtered: ash 0.005, organic 0.03. The total air flow rate in the furnace is 15000, including, for a melt mirror of 150-200 air. The air jet is inclined to the surface of the melt mirror at an angle of 15 °, and the jet axis passes at a distance O, 17P from the center of the furnace. Sulfur is continuously withdrawn from the conical part of the furnace with sediment of solid impurities in the amount of 108.8 kg / h to the septic tank, from where it is transferred to filtration. 8.8 kg / h of cake is discharged from the filter, and pure sulfur in the amount of 100 kg / h is added to the main stream and goes to the furnace for processing. The sulfur burning process is limited by the slowest stage — evaporation, the amount of sulfur evaporated is 800 kg / h.

Process indicators: the dust content of the production gas stream is 0.04 g / nm, the degree of gas dust reduction as compared with the prototype is 2.5 times, the sulfur loss is 4.4 kg / h or

5.1586995

, 17% of the total amount of sulfur, the feed

The sulfur serum is lower than sulfuric sulfur oxide 15–4

burnable, the kiln capacity is 2500 kg / h, which corresponds to the kiln output of the desired product.

Thus, carrying out the process of burning sulfur under the proposed conditions allows, while maintaining the productivity of the furnace, to reduce the productivity, dust content of sulfur dioxide by 2.44-4 times and the loss of sulfur with cake by 20-25 times.

Claims (2)

1. A method of producing sulfur dioxide from sulfur contaminated with ash impurities, including the supply of sulfur to the furnace with a layer of liquid sulfur, the supply of oxidant gas to the layer of sulfur and into the superlayer  all over space and removal of the cake from the lower part of the furnace, characterized in that, in order to reduce the loss of sulfur from the cake and reduce the content of drums in the target product while maintaining the productivity of the process, 4-20% of sulfur is continuously removed from the lower part of the furnace from the mass of sulfur loaded, followed by the introduction of cake from it by filtering and returning the purified sulfur to the furnace, and the oxidant gas is supplied to the surface of the sulfur layer by a jet directed at an angle of 15-45 °. 2. The method according to Claim 1, which differs from the fact that the jet of oxidizing gas is supplied to the surface of the sulfur layer at a distance of 0.17-0.40 from the vertical axis of the furnace. gal-oxidizer uiflon