Relationship between sintering index and grade
After the concentrate grade is increased, the SiO 2 content in the concentrate is reduced. Therefore, in the sintering production, the flux consumption per ton of sinter is reduced, the iron consumption is increased, and the sinter grade is increased. The Ertie Plant is mainly based on Nanfen Concentrate and is equipped with a small amount of Shantoushan concentrate. An iron plant uses all the Shantoushan concentrates and does not need rich mineral powder. Therefore, an iron plant to analyze the quantitative relationship between the sinter grade and the concentrate grade is a problem. Formula in terms of Fe --- transducer sintered ore grade at a certain alkalinity,%; Shougang has done a lot of statistics and calculations on the influence of concentrate grade and sintering and blast furnace smelting. According to the actual production situation of the Shougang Sintering Plant in the first half of 1980 (90.27% of the refinery concentrate powder in the sintered iron ore powder) and 100% of the sinter plant with the Qian'an concentrate powder, calculate the different Qianjing fine The effect of the grade (from 66 to 69%) on the grade and cost of the sinter, the result is: Stainless steel Flat Bar Stainless steel Flat Bar Zhonglian Yongsheng Special Steel Co.,Ltd , https://www.zlysssteel.com
As a result of calculation of some acid ore sintering ingredients, the concentrate grade is increased by 1%, the flux consumption per ton of sinter (CaO/SiO 2 = 1.20) is reduced by 20 to 25 kg, and the iron consumption is increased by 13 to 15 kg. The grade is improved by 1.5 to 1.7%. The results of the Soviet Union study show that the grade of concentrate is increased by 1% and the grade of sinter is increased by 1.5%. The calculation result of Dagangshan Concentrate of Anshan Iron and Steel Economic Research Institute is: when the concentrate grade is 63.5-66.5 Between %, the concentrate grade is increased by 1%, the grade of sinter can be increased by 1.7%. The alkalinity is between 1.20 and 1.35%, the dry amount of sinter ore is reduced by 8 to 9 kg, and the flux consumption is decreased by 23 to 25 kg. The iron material is increased by about 13kg.
The relationship between the grades of sinter ore in the two ironworks of Benxi Iron and Steel Co., Ltd. is also very clear. The actual production indicators from 1974 to 1980 are shown in Figure 1, Figure 2. 
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Since the alkalinity of the sintering production is constantly changing, the grades of the sintered ore that have been tested cannot be directly compared, but must be converted to the same alkalinity before being comparable. The conversion formula is as follows
Fe——-the grade of sintered ore before conversion, %;
CaO—the content of CaO in sinter, %;
SiO 2 — SiO 2 content in sintered ore, %;
R exchange --- converted into sinter alkalinity.
The sinter grades of an iron plant are converted to the same alkalinity (CaO/SiO 2 = 1.30), and the results are shown in Fig. 3. The grade of Shantoushan concentrate increased by 1%, and the grade of sinter of an ironworks (at CaO/SiO 2 = 1.30) increased by about 1.6%.
(1) According to the first half of 1980, 90.27% of Qian'an fine powder was used to increase the grade of concentrate by 1%. The iron content of sinter increased by 1.5 to 1.577%, with an average of 1.54%. The cost of sinter increased by 0.22~0.27 yuan/t. , an average of 0.242 yuan / t.
(2) According to the ratio of 100% Qian'an concentrate, increase the grade of concentrate by 1%. The increase of iron content in sinter is 1.68~1.78%, with an average of 1.72%. The cost of sinter increases by 0.31~0.323 yuan/t, with an average increase. 0.317 yuan / t (according to the 1980 price).
The calculation results for different concentrate grades of Angang Steel Mine (sintered by 100% concentrate) are: the concentrate grade is increased by 1%, the grade of sinter grade is increased, 1.69% of Dagushan concentrate; 1.73% of Donganshan concentrate; Dashan Concentrate 1.64%; Gongchangling Concentrate 1.75%.
There are two reasons for the increase in the grade of sinter ore. One is the effect of the improvement of concentrate grade itself; the effect of increasing the consumption of concentrate per ton of sinter concentrate and the reduction of flux consumption. The actual increase in the grade of sintered ore in the actual production is different from the calculated results. The reasons are: (1) the actual production rarely burns a single ore, often with some ore powder; (2) the sinter alkalinity in recent years. Constantly improved, the basis of comparison is inconsistent.