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PIG IRON
EXPERIMENTAL INDUSTRIAL PLANT
FOI~ CALCINING LUMP SIDERITE
N. V. Fedorenko, V. I. Kitaev,
V. V. Chervotkin, A. G. Zhunev,
E. S. Gusev, and N. V. Neryakhin
UDC 669.1.622.782.4
A calcining-concentration plant (CCP) consisting of nine shaft furnaces with a total volume of 400 m 3 and design
output of 750,000 tons of raw siderite per year was put into service at the Bakal Ore Preparation Combine in
1972.
Siderite with a size of 60-100 mm is delivered from the crushing-grading plant (CGP) by a conveyer belt to
the receiving hoppers of the CCP and then by double-bell charging apparatuses into the furnaces. Loading and unloading
the ore is periodic. The rate of unloading the calcined product is regulated by changing the periodicity of
turning on the shuttle feeder. After cooling in louvered hoppers the siderite is sent to the screening building. The
lump product is shipped to metallurgical plants and the fines 8(5)-0 mm are sent to the stockyard.
The shaft furnace (Fig. i) consists of four vertical chambers (shafts) with a height of 7 m and cross section of
0.7 x 2.2 m which are separated by partitions (cores). From an outside furnace the combustion products of natural
gas pass along flues through the gas-distribution ports into the calcining zone and penetrate the siderite from the bottom
upward. The technical characteristics of the furnace (design) are presented below:
Output of calcined siderite, ton/h . . . . . . . . . . . . . . . . . . . . . . . . . 7.4
Temperature in calcining zone, *C . . . . . . . . . . . . . . . . . . . . . . . . . 950-1050
Consumption of natural gas, mS/h . . . . . . . . . . . . . . . . . . . . . . . . . 340-380
Volume of furnace chamber, m 3 . . . . . . . . . . . . . . . . . . . . . . . . . . 12.8
Number of burners (GIP-6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Quantity of air for diluting combustion products in furnace, m3/h . . . . . 2000
Quantity of air for cooling 1 ton of siderite, m 3 . . . . . . . . . . . . . . . . . 3000
Time siderite is in furnace by zones, h
heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
calcining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1
hardening and precooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8
We see from the operating indices of the plant presented in Table 1 that the average monthly quality of the
initial siderite was relatively constant. However, its chemical composition according to the average daily samples
had considerable fluctuations. Thus, the content of Fe varied from 23.5 to 41.7%, Fe20 s from 4 to 35%, CaO from
I to 11%, and S from 0.08 to 2.0%. Such variations are due to the absence of blending. After calcining the content
of iron increased by 10.94-12.51%.
The high residual calcination losses and insufficient removal of sulfur were due to the low calcination temperature
(in the flues the temperature did not exceed 1200~ Investigations showed that at this temperature the design
calcination regime is not attained. The causes of disturbance of the thermal conditions of the furnaces were nonrhythmic
operation of the plant owing to nonroutine repairs which in some months reached 8-9% of calendar time,
impossibiIity of delivering siderite from a blending stockyard, and the small capacity of the receiving hoppers of the
CCP, which did not provide continuous operation of the furnaces in the event the arrival of ore from the CGP stopped
Chelyabinsk Scientific-Research Institute of Metallurgy. Bakal Ore Preparation Combine. Ural Scientific-
Research and Planning Institute of Concentration and Mechanical Proce~ing of Minerals. Translated from Metallurg,
No. 10, pp. 9-10, October, 1973.
_9 1974 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West l?th Street, New York, N. Y. 10011. No part
of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical,
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