SU1059014A1 - Method for pelletizing overmoistened finely communicated materials - Google Patents

Abstract

1. METHOD OF GRANULATION OF IMPROVED TIN-SUBSTITUTED MATERIALS, for example, iron-containing concentrates, including their form-to-deposits. ; mirovanie in the form of separate jets, pelletizing with the return of the non-conditioning fraction -5 mi heat treatment, .0 tons l and .4 a y w and so that, in order to increase the content of the conditioned class, the strength of the granules and productivity plants, pereuvlgiknenny material is formed into compacted jets of 5-10 mm in size, the substandard fraction is dried to 5-10% moisture, and then the mixture of material and substandard fraction is granulated in a gas stream heated to 100-300 ° C. 2. Sposes according to Clause 1, v. Tl and h ay i and with leMf. that the ratio of the dried substandard fraction supplied to the granulator and the crumpled material is

Description

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The invention relates to pelletizing (granulation) over-wetted by the separation of organic materials (for example, flotation process concentrate) and can be used in ferrous, color metallurgy, chemical, food industry and other industrial sectors. from wet SELT materials and their further heat treatment l. However, this method of producing grunl is difficult to implement due to the fact that the formed jets further stick together or, if they are dried, t granules are poorly suited since their surface is dry and particles sticking, i.e., the growth of granules is difficult.The closest to the proposed technical essence and the achieved result is the method of pelletizing bulk materials, including their formation in the form of separate jets and pelletizing with the return of the substandard fraction of -5 mm. The gift of the formation of two: or several streams of clumping material directed towards, an intensive growth of granules occurs. In addition, it is possible to obtain conditional grains from materials, whose moisture content is 0.5-G, 0% higher than the optimum moisture content of the crumpled material 2. However, the known method does not allow to intensify the process of pelletizing of overwetted supertones of crushed materials and to improve the granulometric composition of the pellets (granules) due to the fact that during the superfine grinding of bulk materials a large amount of sludge is formed, which prevents deep dehydration of materials in vacuum filters and reduces the performance of sweets in the vacuum filters and reduces the performance of sweets. The purpose of the invention is to increase co. conditional grade, granule strength and plant performance. The goal is achieved by the fact that according to the method of granulation of wetted, for example, iron-containing concentrates, sharpened materials, concentrates, including Iy, their formation in a bidet of individual jets, pelletized with an unconditioned fraction of -5 mm and heat treatment, the overwetted material is formed in the jet compaction with a size of 5-10 mm, the sub-standard fraction is dried to 5-10% of the current, and then the mixture of material and substandard fraction is granulated in a gas stream heated to 100-200 ° C. In this case, the ratio of the dried substandard fraction supplied by the P granulator to the lumped material is (1: 5) - (1:10). The method is carried out as follows. The overwetted mass of the crumpled material is formed into compacted jets of 5-10 mm in size, fed to the pelletizer together with an off-spec fraction and granulated in a gas stream heated to 100-200 ° C. By separating the moving mass of the clumped material into 5-10 IAM jets, the formation of granules from them is facilitated. At the same time, simultaneous feeding of non-conforming fraction dried to 5–10% of moisture into the granulator eliminates jet fusion. Granulation in the pelletizer contributes to the rapid breaking of dried (due to contact with the substandard fraction and gas flow) jets into separate units, which then become spherical as they are rolled. As it progresses along the pelletizer, the granules are strengthened by bringing the particles closer together under the action of their impact and drying. The optimum size of the streams of a crumpled material is determined as follows. With a size of less than 5 mm, the number of small, substandard granules in the finished product increases, which leads to a decrease in the efficiency of pelletizing. If the size of the jets is more than 10 mm, the granules formed in the pelletizing process are larger than the upper limit for granulation and the number of conditioned pellets decreases, which also reduces the efficiency of the pellet. The moisture content of the dried substandard fractions -5 MI- should be 5–10% abs. humidity. When the humidity is more than 10%: the granulation conditions are disturbed, as aggregates formed from jets of material transfer worse the excess moisture to the particles of substandard fractions, which contributes to the formation of a large number of substandard (large) granules and leads to a worsening of pelletizing. When the moisture of substandard fractions is less than 5%, there is a significant dehydration of the combed material, the average diameter of the formed granules decreases, the amount of fines increases, and the capacity of the plant according to the standard class is reduced. The formed and dried granules are further heat treated as required. The ratio of the non-conforming fraction supplied to the granulator is (1: 5) - (1:10) in relation to the starting material and is optimal. When the ratio of these fractions and material is more than 1: 5, their number is large and a part does not participate in the granulation, but circulates in the pelletizing system, which leads to unnecessary expenditure of energy. With a ratio of substandard fractions of -5 mm and material less than 1:10, they are not enough to create optimal granulation conditions, jets or sludge aggregates formed from them are combined with each other, and large (off-grade) materials are obtained, which reduces the quality of the finished product. When the gas temperature is less, drying of the lumpy material is dragged out and an increased number of large aggregates (lumps in the finished product, fine material (the returge is not dried sufficiently, which reduces the quality of pelletizing. When the gas flow temperature exceeds 200 ° C, the material dries out, which leads to to the formation of a large number of substandard fractions of-5 mm. Choosing the minimum required temperature of the gas stream, depending on the moisture content of the coagulated material and G pelletizing of 5–10 mm dried off-10% moisture of substandard fractions is 5 mm. The maximum yield of conditioned pellets is achieved at a min: maximum heat carrier flow. Gas flow temperature, the amount of pre-sieve product (screen retrau with cell size of 5 mm and substandard moisture of -5 mm are interrelated : the more tempo9, 9

10.2 100

7.0 130

6.9 130 6.4 150 3.5 200 1.5 280

2.3

80

79.6

8.1 82j9 9.8

7.3 82.7 6.0

11.3 85.0 5.2

9.8 79.8 5.2

15.0 1.5 76.2

22.3 0.8 45.2

54.0 gas treatment, the greater the number of substandard fractions -5 mm and less moisture. The range of limits for the optimal variation of these parameters is experimentally obtained when conducting semi-industrial tests. The results are presented in Table. 1. At measures. The pelletizing is carried out in half a millet conditions of the flotation concentrate of the Chilisay field of the following composition,%: Class - 40 µm 75; 24.2; C02 5.24. Granulation is carried out with the known and proposed (allowances at a concentrate moisture content (optimum moisture for pelletizing 16.2%) in an icicle pellet with a diameter of 1200 MP and a length of 4000 mm with a capacity of 300 kg / h. The starting material is fed to the auger, at the outlet of which streams of material are formed with a diameter of 8 mm, which enters the pelletizer together with a 8% moisture content of 15% of the amount of material received. An air heated to 120-140 ° C is fed into the pelletizer. The pelletizing time is 3-4 minutes. Omkovatel granules are screened into 5 mm and -5 mm classes, the averaged data of the finished product for a series of 25 samples taken are shown in Table 2. The use of the proposed method of granulation of wetted ultrafine ground materials provides an increase of 50 -80% with a simultaneous decrease in the pelleting time and an increase in the strength characteristics and a decrease in the porosity of the granules, which favorably affects their subsequent heat treatment. 89.5 10.2 - Known 2.5 96.2 1.2 Suggested

Table 32.1 0.42 35.9 21.5 0.98 30.6

Claims (2)

1. METHOD FOR GRANULATING OVER-MOISTURED FINE-MILLED MATERIALS, for example, iron-containing concentrates, including their formation, formation in the form of separate · jets, pelletizing with the return of non-conditioning fraction -5 mN and heat treatment ', so on and The reason is that in order to increase the content of the air-conditioning class, the strength of the granules and the productivity of the installation, waterlogged material is formed into compacted jets of 5-10 mm in size, the substandard fraction is dried to 5-10% humidity, and then the mixture of material and substandard fractions are granulated in a stream of gas heated to 10–300 ° C. 2. The method of claim 1, OT ich l and w / w and D with I ,, so that the ratio dried substandard fraction po- _β being given into the granulator and komkuemogo $ material is (1: 5) - (1: 10). _l "to. > 10 5 9 014 to be used in the ferrous, metallurgy, chemical, and other industries