SU1757999A1 - Method of pelletizing of phosphate stock - Google Patents

Abstract

The invention relates to the technology of preparation of phosphate raw materials for processing it into phosphorus. The method consists in crushing phosphate raw materials, dividing it into fractions minus 10 mm and lump fraction 10-20 mm, grinding the first fraction to a class minus 0.1 mm, wrapping it with a binder, moistening lump phosphate to a moisture content of 2-3 wt.% , rolling the first fraction on it in the amount of 5-10 wt.%, loading the pelletized first fraction onto the layers of lumpy phosphate and drying them and firing at 1100-1180 ° C. 1 tab.

Description

The invention relates to the technology of agglomeration of phosphate raw materials intended for the production of phosphorus in electrothermal furnaces.

Closest to the proposed process is a method of agglomeration of phosphate raw materials, including crushing it, dividing it into two fractions: minus 10 and 10-20 mm, placing a large fraction on the grate of the roasting machine, grinding the fines fraction minus 10 mm to 0-0.1 mm, wetting and rolling with a binder, loading raw granules into lumpy phosphorite, drying and burning the material at 1027-1077 ° C.

The disadvantage of this method is the low strength of the product, due to the low strength of lumpy phosphate - 5.3-8.5 MPa.

The purpose of the invention is to increase the strength of the product by increasing the strength of lumpy phosphate.

This goal is achieved in that the lumpy phosphorite fraction of 10-20 mm is moistened before laying on the grate of the roasting machine to a moisture content of 2-3 May. % and it rolls a fraction of 0-0,1 mm in the amount of 5-10% by weight of raw materials.

Example. Phosphate ore of the Janatas deposit in the amount of 30 kg was crushed and divided into two fractions minus 100 mm (12 kg) and plus 10-20 mm (18.0 kg), and the fine fraction (-10 mm) was crushed to fraction 0- 0.1 mm, and the coarse fraction (+ 10-20 mm) is moistened with water to a moisture content of 3%. The crushed fosmuk in the amount of 1.8 kg (10% of the mass of lumpy phosphate) is rolled onto the surface of lumpy phosphorite on a granulator of 1000 mm with a bead height of 50 mm and laid onto a grate of roasting mm in a layer of 260 mm. The remaining part of the formula in the amount of 10.2 kg is moistened with water, pelletized into pellets 0.20-20 mm and loaded onto

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a layer of lumpy phosphate 140 mm high. Raw granules and rounded lump phosphorite is subjected to heat treatment in the following mode:

Drying: heating from above for 4.5 minutes at a heat carrier temperature of 190 + 10 ° C and a filtration rate of 0.4 m / m-s; blowing from the bottom for 12 minutes at a heat carrier temperature of 210 + 10 ° С and a filtration rate of 1.5 m3 / m2 s; roasting: heat carrier temperature 1150 + 15 ° С at a filtration rate of 1.55 m3 / m2 s for 18 minutes.

The disassembly of the calcined pellets and lumpy phosphate is carried out by visual inspection, with lumpy phosphorite accounting for approximately 2/3 of the total material.

Mechanical strength of pellets: compression 223 kg / ok; drum sample: on impact (fr. +5 mm) 93%; for abrasion (FR-0.5 mm) 6%.

The mechanical strength of lumpy phosphorite (average of 10-50 determinations): a breaking load of 18 MPa, a degree of calcination of more than 95%,

The output of the stuff minus 5 mm after heat treatment of 0.5%. The average strength of the product (mixture of lump and granular phosphate) is 180 kg / pc for compression, 94% for impact, 5% for abrasion.

PRI mme R 2. Phosphorite of the Janatas deposit in an amount of 30 kg is subjected to crushing, screening and separation into fractions - 10 (12 kg) and + 10-20 mm (18 kg). Then the fine fraction (-10 mm) is crushed to 0-0.1 mm, and the coarse fraction (+ 10-20 mm) is moistened with water to 2% by weight and doused with 0.9 kg of the nozzle (5% by weight of lumpy phosphate) .

The resulting material is placed on the grate of a roasting bowl with a height of 230 mm, the remaining part of the nozzle in the amount of 11.1 kg is poured into pellets of 0-10-20 mm and loaded with a layer of 170 mm.

Raw granules and treated phosphomus lump phosphorite is subjected to heat treatment as in example 1.

Mechanical strength of lumpy phosphorite (average of 10-50 determinations): breaking load 15 MPa, degree of calcination more than 95%.

The mechanical strength of pellets for compression is 205 kg / ca., drum sample: for impact (fr. +5 mm) 92%, for abrasion (fr. -0.5 mm) 6%. The output of the stuff minus 5 mm after heat treatment of 1%.

The average strength of the product (mixture of lump and granular phosphorite) is 169 kg / pc for compression, 93% for impact, 6% for abrasion.

EXAMPLE 3 Analogously to Example 1, lump phosphorite of the Janatas deposit was crushed and divided into two fractions minus 10 mm (12 kg) and + 10-20 mm (18 kg), the coarse fraction was moistened with water to a moisture content of 1, 5% and a dust-like fraction is rolled on its surface in the amount of 4% of

the mass of lumpy phosphate (0.72 kg), and the remaining part of the phosphomus in the amount of 11.28 kg is moistened with water, pelletized into granules, dried and calcined as in Example 1.

Mechanical strength of pellets: compression 240 kg / approx., Drum sample for a shock of 92%, for abrasion of 7%.

Mechanical strength of lumpy phosphate: breaking load 8 MPa, degree of calcination 93%; the output of the little things 5 mm after heat treatment 5%.

The average strength of the product is 137 kg / pc for compression, 92% for impact, 7% for abrasion,

Example 4. The crushing of lumpy phosphate, fractionation, grinding of the small fraction is carried out as in Example 1. The coarse fraction is moistened with water to a moisture content of 3.5% and 2.16 kg of fosmouq (12%) are rolled. Drying and roasting of raw materials are also carried out analogously to example 1.

Mechanical strength of pellets: compression 210 kg / approx., 94% impact, abrasion resistance6%.

Destructive load of lumpy phosphate 18MPa, the degree of calcination 95%, the yield of fines 5 mm, 3%. However, in this mode of pelleting, pieces of phosphorite are sintered among themselves, which violates the mode of operation of the roasting bowl.

EXAMPLE 5. 30 kg of phosphorite is subjected to crushing, sieving and grinding of the fine fraction under conditions similar to

Example 1. The phosphorite fraction + 10–20 mm is moistened to a moisture content of 2.5% and 1.35 kg of phosphorus (7.5% of the mass of lumpy phosphate) is rolled onto its surface. Drying and roasting of the raw granules and lumpy phosphate is carried out under conditions similar to example 1.

Breaking load of lumpy phosphate 16 MPa, the degree of calcination 95%. The mechanical strength of the pellets is 248 kg / approx.,

granule yield 5 mm after heat treatment 0.75%.

The average strength of the product is 205 kg / pc in compression, 95% per impact, and 4.5% in attrition.

Analysis of these examples shows that moistening of lumpy phosphate to a moisture content of 2-3%, followed by pelleting it with phosphomus of a 0-0.1 mm fraction, taken in an amount of 5-10% of the mass of lumpy phosphate, are the optimal parameters of this process.

Reducing the consumption of fosmuki (less than 5%) for enveloping lumpy phosphate, moistened to a moisture content of less than 2%, leads to a decrease in the average strength of the product (137 kg / pc), as evidenced by the yield of fines minus 5 mm (up to 5%) .

An increase in the consumption of fosmuki (more than 10%) for the pelleting of lumpy phosphate, moistened to a moisture content of more than 3%, although it does not reduce the strength of lumpy phosphate, but causes the sintering of individual lumps, which is accompanied by an increase in the yield of the fraction minus 5 mm (more than 3%) due to for the need of crushing.

Comparative data on the effectiveness of the known (prototype) and proposed processes are presented in the table.

The proposed process is compared to

the prototype makes it possible to increase the average strength of the resulting product by increasing the strength of the calcined lumpy phosphate.

Claims (1)

Invention Formula Method of agglomeration of phosphate raw materials, including its crushing, separation into a fraction minus 10 mm and lump fraction 10-20 mm, grinding the first fraction to a class minus 0.1 mm, wrapping it with a binder, laying on the grate of the firing machine on a layer of lumpy phosphate , drying and roasting at 1100-1180 ° C, characterized in that, in order to increase the strength of the product by increasing the strength of lumpy phosphate, it is moistened before laying to a moisture content of 2-3 wt.% and a fraction of minus 0 rolls on it , 1 mm in the amount of 5-10% of its mass sy.