RU1803381C - Method for sintering of phosphate raw material - Google Patents

Abstract

Essence: lump phosphorite with a CO2 content from 3.0 to 12.0% is loaded onto the grate. The layer is profiled, forming a furrow with a depth determined by the formula: h b2 + 10 (a-3), where h is the furrow depth, mm, b is the height of the protective layer on the lattice, mm, and a is the COa content in the piece. An agglomeration charge of fines of phosphorite, return and coke is loaded onto the obtained layer. The mixture is ignited, sintered when air is sucked through the bed. The agglomerate is cooled and a mountain product is recovered. The content of S02 and 50g in sintering gases is 170-300 mg / m, the degree of decarbonization is 97.5%. 1 wpp, 5 examples, 1 tab. Yo

Description

The invention relates to the field of preparing phosphate feedstocks for the electrothermal production of yellow phosphorus.

The aim of the invention is to reduce emissions of sulfur compounds. (S02 and 50h), increase the degree of decarbonization of phosphorite with content. CO2 from 3.0 to 12.0% and a reduction in energy costs for the process.

To achieve this goal, before loading the sinter charge on the grate, lay a layer with a height of 70 mm of lumpy (70-5 mm) phosphorite with a content of Р02 from 3 to 12%, the layer is profiled, forming a furrow with a depth determined by the formula:

h | +10 (a-3),

where h is the depth of the furrow, mm;

b is the height of the protective layer on the grate, mm;

and - the content in a piece of CO2, honeycomb dol.

The frequency of the furrows is set according to the angle of repose of the piece and the maximum depth of the furrow.

In this case, the angle of repose of phosphorite is 70-5 mm 45 °, the maximum furrow depth is 100 mm, respectively, the distance between the centers of the furrows is 200 mm. The proposed method for the agglomeration of phosphate raw materials allows to reduce emissions of sulfur compounds (S02 and 50h) from 800 to 170 mg / m3, to increase the efficiency of the process due to more complete use of the unit’s production capacity (the calcined piece is used as a suitable agglomerate) and heat and mass flow

00

about

CA W 00

(the heat concentrated in the specimen mass by convection and contact is absorbed by the piece and goes to decarbonization); increase the degree of decarbonization from 50 to 80%.

Example 1 12 kg of phosphorite with a grain size of 5-70 mm with a content of CO2 of 12% and a layer height of 70 mm are loaded into an agglomerate on a grate. Using a plow, which is a wedge with inclined planes at an angle of 45 °, we made grooves in the center and from the center at a distance of 200 mm with a depth calculated by the formula

h | +10 (a-3) ,.

where h is the depth of the furrow, mm;

b - a protective layer of 20 mm;

and - the content of CO2 in phosphorite, honeycomb dol.

On the profiled layer was laid sinter charge, composition,%:

material% phosphorite 10-0 mm 55.8 return 5-0 mm 30.7 coke 3-0 mm 6.5 water 7.0

pelletized in the drum.

kg

21,2

11J

2,5

2.7

The mixture was ignited with a gas coolant with a temperature of 1200–1250 ° C for 2–2.5 min, and then sintered and cooled with constant vacuum under a grate, 9.8 kN. The process was conducted until the temperature of the exhaust process gases dropped from a maximum to 80 ° C. During the sintering-cooling process, samples of the suction process gas were taken to determine the content of sulfur compounds (S02 and ZO3) in them. The cooled cake and lump phosphorite were weighed, crushed and dispersed, tested for mechanical strength according to GOST 15137-77. The gas samples taken were analyzed for a total of 302 and 3O3 in it.

Received:

Amount of heat-treated product - 40.2 kg

Product yield + 5mm - 27 kg 70%

Indicators of mechanical strength according to GOST 15137-77 +5 mm - 72%, -0.5 mm - 7.0%,

The content of CO2 in sinter specimen is 0.3% - decarbonization is 97.5%.

The CO2 content in the piece is 2.4% - decarbonization is 80%. ,

The total content (02 + Oz) is 170 mg / m3.

PRI me R 2. As in example 1, the grate is loaded with 12 kg of phosphorite with a particle size of 5-70 mm, but with a CO2 content of 3%. In the phosphorite layer, furrows with a depth of 200 mm from each other are made

og h 4g + 10 (3-3) 10.

From above, a sinter charge of the same composition as in Example 1 is loaded onto a piece. Sintered and tested as in Example 1. Receive: decarbonization of cake - 97.5%

decarbonization of a piece - 60% Content in process gases total. (302 and ЗОз) -600 mg / m3. The yield of a suitable and durable product at the same level.

PRI me R 3. Everything is the same as in example 1, but lump phosphorite contains CO2 - 60%. In the phosphorite layer, furrows with a depth of 200 mm from each other are made

h

V

10 (6-3) 40 mm.

The rest is as in example 1.

Receive: decarbonization cake - 97.6%,

decarbonization of the slice - 70.1%. Content in process gases total. (S02 + ЗОз) - 300 mg / m3. Yield and product strength on that

same level.

PRI me R 4. As in example 1, but lump phosphorite contains 2.5% CO2. In this case, there is no point in making furrows. Emissions from process gases of sulfur compounds (302 and 3O3) at the level of analogues (800 mg / m. Decarbonization of a piece no more than 50%. The remaining indicators are the same as in Example 1-3.

PRI me R 5. As in example 1, but

lump phosphorite contains CO2 - 12.5%. The depth of the furrow should be

fifty

90 h 4r + 1.0 (12.5-3) 105 mm.

Emissions from process gases of sulfur compounds (S02 and ЗОз) 170 mg / m3. The content of CO2 in sinter specimen is 0.3% - decarbonization is 97.5%. .C02 content in a piece - 2.4% - decarbonization - 80%.

However, in this case there is a risk of damage to the grate during the formation of grooves, and the indicators are at the same level as in Example 1.

From the above examples it follows that in the proposed agglomeration method, the highest rates to reduce emissions of sulfur compounds (S02 and ZOz) from 800 to 170 mg / m3 and increase the degree of decarbonization (from 50 to 80%) are observed if the proposed conditions are observed in examples 1 - 3. Beyond the limit, no progress is achieved.

The table shows the indicators for reducing emissions of sulfur compounds, decarbonization and heat loss of the proposed agglomeration method, its analogues and prototype. An analysis of these shows indicates that the proposed method, in comparison with the analogue and prototype during agglomeration of phosphorites, significantly reduces the release of sphosphate compounds, reduces heat loss and increases the decarbonization of the layer of phosphate materials.

Formula of the invention

Claims (2)

1-. The method of agglomeration of phosphate raw materials, including loading lumpy phosphorite on the grate with subsequent loading onto it of a pelletized agglomeration charge from fines of phosphate, return and coke, ignition of the charge with using coolant, sintering when air is sucked through the bed, cooling, releasing a suitable product and the direction of return with a particle size of less than 5 min to the stage of phosphorite loading, distinguishing also with the fact that, in order to reduce emissions of sulfur compounds, increase the degree of phosphorite decarbonization with a CO2 content of 3-12% and a reduction in energy consumption for the process, the phosphorite layer is profiled before laying the sinter charge on it, forming a furrow with a depth of h y + 10 (a-3), where b is the height of the protective layer on the grate, mm; and - the content of CO2 in a piece. 2. The method according to claim 1, characterized in that the frequency of the furrows is determined by the angle of repose of lump phosphorite and the maximum depth of the furrow. Comparative data of the method of agglomeration of phosphate raw materials Prototype (N.S. Shumakov, A.M.Ku-25 naev. Agglomeration of phosphorites. Aglons-Alma-Ata, 1982) rat 6-16 The proposed method 1 2 3 1 5 Analog (A.S. 933761, ... class With 22V 1 / 16F. BI.21.7. Ob. 82) Phosphorite 5 mm in diameter with coke was laid down on the grate at an angle of natural slope with a coke of 150 mm in height, and a 0-10 mm egloch was placed on top. Total layer height 300 tax (V.A. Ershov. Technologists “OSFORA. 1373, p.135-139 A layer of lump island of 10-50 mm was laid on the grate, 70 layers of sinter charge were laid on it and the agglomeration process was conducted 0..25 8.0 12.0 5,0 .95 800 800 507 97.0 900 850 Siio 8.0 fifty 97.0 Ј00 Ј20 390  -. / r- Y & ,. -, h / O L.CH - -V V -KL0 - and . .a   - - -. "I. V b3 - f ". .Ch - -, .J, m-L.  .v  .v  .: - r T,. , -. g, c.frffl . - ./ -.  - b.: W // .V-; Q -. . . . . J I. 1:  / °, „- ..V -vs A i X / s3 %, t V V G, 4 h-h - V L 2 e. I hL J1 1 / - y  .: U- No.; f- 1, P11 .s ABOUT W% C3 Zoe., B r. her 3 I "and. b § l about : W // .V-; Q -. J I. 1: -vs A i X / s3 m fc ё e about. § (