SU1579897A1 - Method of controlling heat treatment of phosphate material - Google Patents

Abstract

The invention relates to the control of technological processes for the preparation of phosphate raw materials for the electrothermal production of phosphorus, can be used in the chemical industry and improves the mechanical strength of burned pellets. The method involves measuring the intensity of the α - quartz diffraction bands of the source and heat-treated materials and calcium orthosilicate of the heat-treated material, calculating the intensity ratios of the α-quartz diffraction bands of the heat-treated and raw materials and adjusting the fuel consumption depending on this ratio, calculating the ratio of the diffraction bands α - quartz intensity to the sum of the intensities of α - quartz diffraction bands and calcium orthosilicate of the heat-treated material and is regulated e speed of the material and / or heat-treated flow of material depending on this ratio. 1 hp f-ly, 4 ill. 1 tab.

Description

This invention relates to process control for the preparation of phosphate raw materials for electrothermal phosphorus production and can be used in the chemical industry.

The purpose of the invention is to increase the mechanical strength of the calcined pellets by increasing the accuracy and reliability of the heat treatment process control.

Figure 1 is a schematic diagram of the control of the heat treatment process; figure 2 - dependence

the strength of the calcined pellets from the X-ray index; on fig.Z - dependence of the strength of the agglomerate from the X-ray structural index; figure 4 - dependence of the strength agglomerated phosphate material from the x-ray index.

The control circuit (Fig. 1) contains a pelletizer drum 1, a hopper 2 and head tanks, an agglomeration machine 3, samplers 4, X-ray spectrometer 5, transducers 6, comparison unit 7, control blocks 8, blocks

SL

one

& oo co

one

9 control units 10 comparison and feedback controller 11

The method is carried out as follows.

The sintering mixture is fed to the pelletizing drum 1, the pelletized charge is transferred to the bunker 2 of the storage bins and placed on the grate of the sintering machine 3. At the end of the heat treatment, a sample of the calcined product (Ј) is taken from the X-ray spectrometer 3, and the report is applied to a table, 4 chars, and a table is applied. phosphorite (fu) and analyzed there.

The intensity of diffraction bands of quartz d / n 3.34 of source 1IX and heat-treated I 3 materials and the intensity of diffraction band of quartz d / n 4.25 and the sum of intensities of bands of quartz and calcium orthosilicate Ca2Si04 d / n 3.34 are determined -3.38 heat treated material (+ I s8) in the range of angles d 10-14 °.

According to the obtained X-ray structural parameters, the ratio of the intensity of σ-quartz bands in the thermally treated sample to the intensity of the same bands of the feedstock is determined.

., Ez

 (further denoted by 1)

 out

and intensity ratio -quartz

to the sum of the intensity of the quark and

(hereinafter obo4, 25

Ca, SiO,

. 2. 4 w + i3-58

we mean 12)

For each sample of pellets and agglomerate, we determine the impact strength, drum abrasion, and for pellets, the ultimate compressive strength. Experimental data are given in the table, by which the dependences of the strength properties of an agglomerated material on the X-ray structural parameters are established.

With a decrease in the X-ray structural index (Figures 2 and 3) to 0.4, the strength of the pellets increases with a further increase, the abrasion resistance decreases slightly.

This dependence is explained by the fact that at temperatures above 1200 K, quartz, which is part of phosphate ores up to 30%, melts and, upon cooling, passes mainly into the glass phase, which is X-ray amorphous

0

five

0

five

0

on. At higher temperatures, more melt is formed, while cooling more glass is formed, which is undesirable because it is more brittle and a large amount of glass phase reduces the strength of the heat-treated phosphate material, especially by abrasion. X-ray structural index 11 illustrates the phase composition of the heat-treated phosphate material, it establishes the temperature regime and the end of the sintering process. The optimal value of the indicator is 1, 0.4- -0.6. In this range, the compressive strength of the pellets can be represented by the expression:

with 3.5 (1 - I,), kN / ok., the strength of the agglomerate at the output of the class + 5 mm

b 90 - 50 I ,,%.

In addition to liquid-phase sintering, solid-phase reactions are involved in the hardening of the agglomerate pellets. Phosphate raw material in its chemical composition contains calcium oxide, which, reacting with silicon oxide, forms calcium silicates in the solid phase.

The dependence of the strength of the agglomerated phosphate raw material on the X-ray structural index 1g, shown in FIG. 3, characterizes the degree of calcium orthosilicate formation

2CaO + Si02 - CazSi04, which is proportional to the strength of the heat-treated material. The optimal value is

five

0

five

tel 12 "0.18 - 0.24.

The strength of the agglomerate depends on the sintering conditions (laboratory and industrial), the type of fuel, etc., but in each individual case it is proportional to the X-ray diffraction parameter 1 and for an industrial agglomerate, the impact strength can be represented by the expression

C - 134-333.3 1g,

for phosphate pellets, impact strength is an expression of C1 - 152 - 316.6 g.

The signal I from the X-ray spectrometer 5 is fed to the converter 6, where it is converted into an electrical signal U and then fed to a comparison unit 7, to which also a given signal 1,, hell "0.4-0.6. With

Increasing the value of 1 bpoc 8 of the control unit increases fuel consumption (coke breeze during agglomeration or gas when roasting pellets) and reducing 1 with respect to a given value reduces fuel consumption,

The 1 "signal from the X-ray spectrometer 5 is fed to another transducer 6, where it is converted into an electrical signal U and then fed into, the comparator unit 7, to which the predetermined signal is also fed - 0.24. With an increase in the value of 1 "relative to a given value, the rate of movement of the material and / or the consumption of the heat-treated material decrease (the height of the material loaded on the grate).

Example 1 “The prepared mixture is loaded onto a grate, heat-treated, a sample of the initial and heat-treated material is sampled by heat treatment, analyzed on X-ray: -y spectrometer, the intensity signal is fed to the converter 6, where it is converted into electrical proportional I U; Iz U, and supplied to Comparison Unit 7. When using the installation of the Drone-UM computer with the Spark computer, mathematical operations are carried out on an EVM and additional DACs are introduced. If the signal 1 {does not go out of the specified interval (0.4-0.6), and the 1Ј signal from the interval (0.18-0.24), then no signals are output at the output of the comparison block 7, and if the device is in steady state, control signals are not generated in control units.

Example 2. Preparation, heat treatment, removal of spectra and their processing are carried out analogously to example I. If I, 0.6, a, 18-0.24, therefore, there is not enough heat in the sintered layer to form the structure of the material, then in block 7 comparison, a signal appears

U

through the control block 8 is fed

The regulator 9, which increases the fuel supply, simultaneously sends a signal to the feedback channel to adjust the speed of movement and / or consumption of material,

Example 3. Analogously to example 1. If I - 0.4-0.6, and I 0.24, therefore, the strength of the flowing material is below the optimum, in the block

1579897

7, a signal U2 appears, and through control unit 8 signals are sent to the regulators 9, which change the speed of movement and / or

consumption of heat treatable material €

The proposed method is universal and can be used.

both for agglomeration and for pellet firing. The accuracy and reliability of the heat treatment process control is achieved by adjusting by two parameters, characterizing

the end of the heat treatment process: the structure and strength of the heat-treating material.

0

five

0

Claims (1)

Invention Formula 1, A method for controlling a heat treatment process of a phosphate material, including controlling the flow rate of the heat-treating material, the fuel consumption for heat treatment, and the speed of the material moving during the heat treatment process depending on the mechanical strength of the heat-treated material, so that that, in order to increase the mechanical strength of the calcined pellets by increasing the accuracy and reliability of the heat treatment process control, X-ray spectral analysis of the initial and Thermally processed material, measured the intensity of the diffraction bands of the od-quartz of the source and heat-treated material and calcic orthosilicate of the heat-treated material, calculated the ratio of the intensities of the diffractive band-quartz of the thermally treated and raw materials, which determine the current value of the degree of From the completion of the heat treatment process, the ratio of the intensity of the diffraction bands of the quartz to the sum of the intensities of the diffraction band of quartz and orthosilicate 0 Qi of the heat-treated material, by which the current strength value of the heat-treated material is determined, compares the current value of the degree of completion of the heat treatment process with a specified value and with increasing or decreasing the current value of the degree of completion of the heat treatment process relative to a specified value, respectively five 0 five or reduce fuel consumption for heat treatment, compare the current strength value of the heat-treated material with a given value and increase or decrease the current strength value of the heat-treated material relative to a predetermined value, respectively, reduce or increase the speed of the material and / or the consumption of heat-treating material. 2 "The method according to claim 1 about aphids and s - n and so that the calculated ratio of the intensities of the diffraction bands of the ad-quartz of the heat-treated and the source materials is maintained at a level of 0.4-0.6, and the ratio of the intensity of the diffraction bands - quartz to the sum of the intensities of the α-quartz and ortho-silicate band, the Cagging of the heat-treated material is 0.18-0.24. phospho 0.88 0.267 Pellets Carbonate phosphorite Agglomerate laboratory on p / to PKI Agglomerate laboratory on p / to PKKS Agglomerate from AKM-312 sintering machine 46 92 44 85 95 49 51 20 50 82 75 52,8 74.5 58.4 93.1 94.2 68.0 86.8 87.0 91.5 94.0 95.0 74.5 73.0 69.8 68.5 66.4 66.4 66, 0 63.2 61.5 58.6 70.8 68.1 66.8 57.0 53.6 51.2 40.0 21.0 10.5 6.8 5.1 28.0 14.1 11.4 8.1 5.8 5.0 12.6 9.5 10.2 12.1 14.5 12.3 9.2 12.0 14.3 15.4 10.4 9.6 10.2 11.0 12.0 14.0 Material movement speed Decay material 9 loading height ft} AT 9 Fuel consumption 3 I unit I I § 40 thirty 20 sh  out , 3.34 / -,}. 90 thirty TO 60 so 0.1 0.10 Z22 (rigging Editor N. Yatsola Compiled by G. Ogadanov Tehred J. Morgental Proofreader S. Cherni Order 1990 Circulation 412 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 about TO 0.26 . Subscription