Study of Chemical Products of Blast Furnace Smelting
Abstract Generated abstract
This study examines the chemical products formed during experimental blast furnace smelting of peat fuel and flux materials containing organic peat mass, iron ore, and ash. Gas composition, dust content, and yields of tar, ammonia, unsaturated hydrocarbons, and gas gasoline were measured using chromatographic and coke-chemical analytical methods during smelting with coke mixtures and with peat materials. The results show that the experimental gas had carbon monoxide levels similar to industrial top gas but lower carbon dioxide, while hydrogen and methane increased as peat material use rose and coke consumption declined. Product analyses indicated low tar yield and relatively high yields of gas gasoline and unsaturated hydrocarbons, suggesting substantial pyrolysis of primary tar, and characterized the tar, tar water, and crude phenol fractions.
Full Text
STUDY OF CHEMICAL PRODUCTS OF BLAST-FURNACE SMELTING. REPORT 1
K. K. STRAMKOVSKAYA, S. I. SMOLYANINOV, V. S. ARKHIPOV, G. I. KRAVTSOVA
(Presented by the scientific-methodological seminar of the CTF)
Experimental blast-furnace smelting of peat fuel-smelting materials (TPM), consisting of 57–59% organic peat mass and 41–53% mineral components (iron ore and ash), was carried out on an installation under the conditions described in article [1]. During this smelting, the quality of the gas and its dust content were monitored, and the amount of chemical products was determined: tar, ammonia, unsaturated compounds, and gas gasoline.
The bulk of the tar and the water vapor condensed in the refrigerator and were collected in special receivers.
During operation of the blast furnace, every 30 min the gas was analyzed on an KhL-3 chromatograph, whose column, 2 m long and 4 mm in diameter, was filled with CaX molecular sieves. In addition, after every 5–6 hours of furnace operation the gas composition was determined on a VTI-2 instrument.
The content of chemical products in the top gas was determined by a procedure developed for determining the yields of chemical products of coking [2].
The average composition of the gas obtained during blast-furnace smelting is presented in Table 1. Gas samples 5 and 6 in this table were taken after the end of smelting, when the furnace had been charged with fuel-smelting materials without the addition of coke. The coke was present only in the very lowest part of the furnace.
In compiling the material balance of the smelting, it was shown that the relative amount of gas obtained by pyrolysis of TPM is about 4%. However, the composition of the smelting gas differs somewhat from industrial blast-furnace gas. According to the data of Academician M. A. Pavlov [3], the content of individual components in top gas may vary within the following limits: CO₂—8–12%, CO—28–31%, H₂—1.5–3.2%, CH₄—0.2–0.4%. Hence it is evident that, in terms of carbon monoxide content, the gas of the experimental
Table 1
Average gas composition
| Sample No. | Type of fuel | CO | CO₂ | H₂ | CₙHₘ | CH₄ | N₂ | O₂ | Analysis method |
|---|---|---|---|---|---|---|---|---|---|
| 1. | Coke | 32.5 | 2.0 | 0.6 | — | — | 65.2 | 0.7 | VTI |
| 2. | Coke + TPM | 32.5 | 1.2 | 1.8 | 0.1 | 1.9 | 60.8 | 1.7 | VTI |
| 3. | Coke | 29.2 | 1.8 | — | — | — | 66.9 | 2.1 | KhL-3 |
| 4. | Coke + TPM | 32.9 | 2.1 | — | — | — | 65.6 | 2.4 | KhL-3 |
| 5. | TPM | 32.9 | 2.1 | 4.9 | 0.3 | 0.9 | 58.1 | 1.1 | VTI |
| 6. | TPM | 32.4 | 2.1 | 4.5 | — | 1.6 | 58.1 | 1.3 | KhL-3 |
melting differ little from the top gas. The content of carbon dioxide, however, is considerably reduced. With an increase in the amount of TFM and a decrease in coke consumption during smelting, the amounts of hydrogen and methane in the gas increase noticeably.
The dust content of the gas at the moment when fuel was charged into the furnace fluctuated within the range of 5–11 g/nm³, while in the period between charges it was 1–2 g/nm³. Thus, the gas taken between charges has a lower dust content than the top gas of industrial furnaces [4].
The content of chemical products in the gas and their yield in blast-furnace smelting on peat fuel-flux materials are given in Tables 2–3.
Table 2
Content of chemical products in the gas
| Type of fuel | Gas sampling point | Tar | Ammonia | Carbon dioxide and hydrogen sulfide | Unsaturated hydrocarbons | Gasoline from gas |
|---|---|---|---|---|---|---|
| Coke + TFM | After the cooler | 2,90 | 0,75 | 15,26 | 0,73 | 0,84 |
| Coke + TFM | » | 0,73 | 0,57 | 21,37 | — | 0,74 |
| Coke + TFM | Before the cooler | 2,47 | — | 23,54 | — | — |
| TFM | » | 3,57 | — | 19,56 | 0,80 | — |
Table 3
Yield of chemical products
| Product name | Yield, % by weight on dry TFM | Yield, % by weight on organic mass of peat |
|---|---|---|
| Tar | 2,6 | 4,5 |
| Gasoline from gas | 0,62 | 1,0 |
| Unsaturated hydrocarbons | 0,58 | 1,0 |
| Ammonia | 0,53 | 0,9 |
The low yield of tar (4.5% on the organic mass of peat), and the high yields of gasoline from gas (1.0%) and unsaturated hydrocarbons (1.0%) indicate that under the conditions of this blast-furnace smelting the primary tar underwent strong pyrolysis.
The tar contained: 11.7% phenols, 2.7% pyridine bases, 2.9% carboxylic acids, and 82.7% neutral oils.
In the tar water, the yield of which is about 8% on TFM, the following were found: tar 1 g/l and phenols 5.98 g/l. The separated crude phenols were analyzed by capillary gas-liquid chromatography on a Khrom-2 chromatograph with a column length of 50 m and diameter of 0.25 mm. VKZh-94 was used as the liquid phase. The results obtained (Table 4) show that the crude phenols contain 48% phenol and about 20% cresols.
Table 4
Composition of crude phenols separated from tar water
| Components | Content, % by weight |
|---|---|
| Phenol | 48,0 |
| o-Cresol | 6,6 |
| p- and m-cresols | 12,7 |
| 2,4- and 2,5-xylenols | 1,5 |
| 2,5-Xylenol | 1,3 |
| Not identified | 29,9 |
Conclusions
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The yield of chemical products of blast-furnace smelting of peat fuel-and-flux materials has been determined.
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The composition has been shown of the gas, tar, and phenols dissolved in water from the pyrolysis of peat fuel-and-flux materials.
References
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S. I. Smolyaninov, V. S. Arkhipov, G. G. Krinitsyn. Testing of peat fuel-and-flux materials in a laboratory blast furnace. Present collection.
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L. D. Gluzman, I. I. Edelman. Laboratory Control of Coke-Chemical Production. Metallurgizdat, 1957.
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N. V. Shishakov. Fundamentals of Gas Production. Gosenergoizdat, 1948.
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N. E. Kunakov. Development of the Gas Industry of Metallurgical Plants. Metallurgizdat, 1959.