SU1708759A1 - Method of automatic control of operating conditions of cascade of two extractors in production of extractive phosphoric acid from phosphate raw material pulp - Google Patents

Abstract

This invention relates to the automatic control of chemical process engineering. The purpose of the invention is to increase productivity, filtration, reduce the total loss of phosphorus pentoxide in the production of extraction phosphoric acid, saving reagents, raw materials and energy. The goal is achieved by using computers in the control loop and periodically correcting the ratio of the consumption of sulfuric acid and pulp phosphate raw materials by the concentration of excess sulfuric acid in the second extractor, determined indirectly by the electrical conductivity of the pulp, by the concentration of sulfate ions in the second extractor, determined by by laboratory analysis, by concentration / sulfate ions in the first and second extractors, determined according to a mathematical model. The consumption of pulp from phosphate raw materials is used as a new control action. At the entrance of the extractors cascade, compensation is also made for disturbing influences on the concentration of sulfuric acid, ammonium sulfate and the pulp density of the phosphate raw material by periodically correcting the ratio of the consumption of sulfate-containing reagents to the consumption of pulp from the phosphate raw material with a pulp flow rate . 1 hp ff, 1 ill. ; with 9C / s • ^ s] OSSR < x

Description

The invention relates to the automatic control of chemical-technological processes, namely, the automation of the decomposition process of apatite concentrate pulp in the production of extraction phosphoric acid (EPA), and can be applied in the chemical industry, in particular in the production of EPA and mineral fertilizers from the pulp of natural phosphates using sulfuric acid and ammonium sulfate.

In the known method of automatically controlling the process of nitrogen-sulphate-sulfuric acid decomposition of the phosphate raw material pulp Q, it is proposed to use the consumption of the phosphate raw material pulp as a control effect in the pulp decomposition cascade. However, this method cannot be absolutely transferred to the production of EPA from the pulp of apatite concentrate due to the presence in the case of nitrate-sulfate-sulfuric acid decomposition of the pulp of a new additional reagent - nitric acid.

The closest to the proposed is a known method of controlling the mode of operation of the extractor in the production of phosphoric acid, which is proposed to stabilize the mode of operation of the extractor using phosphate raw materials in the form of flour and is to regulate the concentration of excess sulfuric acid in the reaction pulp by pollereniya constant ratio costs sulfuric acid and apatite with a correlation of the ratio of these costs for the content of sulfate ions (excess sulfuric acid) in the pulp affecting the consumption of sulfuric acid, regulating the temperature of the reaction pulp in the extractor by changing the amount of vacuum, adjusting the level of the pulp in the extractor by changing the flow rate of the reaction pulp to be filtered, adjusting the q ratio of the quantities of liquid and solid phases in the reaction pulp by changing the supply of the working solution to the extractor.

The main disadvantage of this method is that when carrying out the extraction process in a cascade of two extractors, using a pulp of phosphate raw materials and the presence of a new reagent, ammonium sulfate, it does not provide optimal conditions for the processes of phosphorus extraction and phosphogypsum crystallization and, as a result, cannot provide minimal total losses of phosphorus pentoxide and the maximum speed of the filtration process, and therefore the maximum performance of the filtration unit. This is due to the fact that in order to create optimal conditions for the extraction of phosphorus from the raw material into a water-soluble form, which takes place mainly in the first reactor, and the optimal mode of formation and growth of phosphogypsum sludge crystals.

beginning in the first and ending in the second ext actor, and ultimately, to minimize total losses of phosphorus pyoxy, it is necessary to additionally correct the ratio of pulp from phosphate raw materials and sulfuric acid in the concentration of sulfate ions (excess sulfuric acid) in each extractor of the cascade . The formation of a phosphogypsum precipitate with good filtering properties provides an increase in the rate of the filtration process, which

leads to an increase in the productivity of the filtration unit (the amount of the reaction pulp) in terms of the feedstock filtered per day, from 1 m to the filtering weave, and hence

increase the productivity of production of EPC in general,

In the case of the simultaneous supply of all reagents and raw materials to the first reactor of the cascade, the above method does not ensure the regulation of the concentration of excess sulfuric acid in the first apparatus depending on the concentration of excess sulfuric acid in the second, final extraction apparatus, which is not

ensures the formation of a crystalline precipitate of phosphogypsum with good filtering properties.

The disadvantages of the known method also include the use of an indirect estimate of the concentration of excess sulfuric acid and sulfate-ion ion by electrical conductivity (viscosity, density) of the pulp. Determination of the concentration of SOd ions by conductivity

is inaccurate and unreliable so

how an electrically conductive sensor reacts to a whole series of perturbing factors (impurities), existing and actual production, and tends to distort information due to a change in its characteristics over time due to its plastering. & If a part of sulfuric acid is replaced by another sulfate-containing ammonium sulfate reagent, the known method does not allow at all to take into account the fraction of ions 50 that are fed with ammonium sulfate. The absence of continuous reliable information and the concentration of sulfation in the first and second extractors of the cascade of Rezk decreases the effectiveness of this method of stabilizing the mode of operation of the extractor. The absence of a differentiated equalizing effect depending on the technological situation and using the known method as a controlling effect of the consumption of sulfuric acid when supplying phosphate raw materials in the form of a slurry does not ensure the effective stabilization of the ratio of the costs of raw materials and sulfuric acid, which is due to the considerable non-stationarity of the process of changing the pulp consumption of phosphate raw materials. The given method also does not allow to take into account and compensate for the disturbing influences at the inlet hell of decomposition: according to the concentration of sulfuric acid to the lots, the density of the phosphate pulp 1 of the raw material, the concentration of ammonium sulphate, which does not provide resource and energy-saving technology. The aim of the invention is to increase filtration performance, reducing the total loss of phosphorus pentoxide in the production of extraction phosphoric acid, saving of reagents, raw materials and energy. The goal is achieved by using a control computer set (EVD) based on EVB in the cascade control circuit and the concentration of excess acid in the extraction stage, and (when indirectly measuring the pulp electrical conductivity) in the first reactor of the cascade by changing the ratio of the costs of sulfuric acid and pulp phosphate raw materials impact on the flow of pulp with the correction of the ratio of these costs for the concentration of excess sulfuric acid in the second reactor of the cascade, also measured by the conductivity of the pulp. In order to increase the reliability of the reliability of information from conductivity sensors, blocks of increasing the reliability of information are used, implemented programmatically as part of UVK, where averaging of statistical data using the moving average method, filtering random data, checking statistical statistics for reliability, weighting information depending on the degree of its reliability . The presence of these blocks makes it possible to significantly increase the efficiency of the method of automatically controlling the concentration of excess sulfuric acid. With a rigorous approach and consideration, the regulation of the concentration of excess sulfuric acid does not yet provide a qualitative regulation of the concentration of sulfate ions in the cascade, therefore, the correlation of the flow rate of phosphate raw material pulp and sulfuric acid is measured by the sulfate-ion concentration in the second reactor of the cascade, measured by laboratory chemical analysis with preliminary verification of the analysis of the reliability of the statistical information about the technological situation at the time of sampling for Due to the lack of continuous information on the concentration of S0 ions (in the cascade between laboratory analyzes, additional units are added to calculate the concentration of sulfate ions in the 1st and 2nd reactors of the cascade using a mathematical model. The blocks are implemented in software into the composition of UVK. The correlation of the expenses of phosphate raw material pulp and sulfuric acid is carried out periodically according to the calculated concentrations of ZOF ions in the 1st and 2nd reactors of the cascade, which allows us to differentiate the contours of the regulated and the concentration of excess sulfuric acid and the concentration of sulfate ions, and thereby provide optimal conditions for the extraction of phosphorus pentoxide and the formation of phosphogypsum. Thus, one of the main distinctive features of the proposed method is the presence of demarcated control loops for the concentration of excess sulfuric acid and the concentration of sulfate ions, which control the first extractor with the aid of the VOC and correct the control effect from the second extractor. The principal difference is that in order to change the consumption of sulfuric acid and phosphate feedstock when feeding to the cascade in the form of pulp, the flow of pulp of the phosphate feedstock is used as the new control effect. In the known control methods, when using solid phosphate raw materials, the change and stabilization of the ratio of raw material and sulfuric acid is effected by affecting the acid consumption at a given flow of fosfomuk, which does not change its characteristics over time. When feeding raw materials in the form of pulp, these methods are ineffective in terms of the quality of stabilization of the ratio of pulp and acid consumption, since stabilization will be carried out in relation to the consumption of unsteady in time pulp flow. The controlling effect on the acid consumption in this case will vary not only as a result of: deviation of the sulfate ion concentration from the permissible value, but also as a result of an unpredictable change in the characteristics of the pulp flow. The decomposition cascade as an object of prefabrication is characterized by considerable inertia, and too frequent application of control effects (when the interval between controls is commensurate with the transition time) degrades the quality of the process for controlling sulfate ions. When choosing the pulp flow rate as a control action in the proposed method, the change and stabilization of the flow rate of the phosphate feedstock and sulfuric acid occur in relation to the flow rate of the steady-state acid. The accuracy of stabilization in this case, due to the degree of nonshizis4: the arity of the pulp flow, is quite satisfactory for industrial conditions. The advantage is that there is no need to change the control action due to the nonstationarity of the pulp flow. In addition, in the proposed method, a differential control effect is exercised depending on the statistical information about the prehistory of the process, its current state and the specified result of the control. The block of generation of differentiated control actions is programmed. A distinctive feature is also the presence of new controlled parameters that allow accounting and compensation of disturbances at the input of the 1st extractor. Additionally, the densities of sulfuric acid, ammonium sulfate, and phosphate raw materials pulps are measured; The concentrations of sulfuric acid, ammonium sulfite and the amount of raw pulp in terms of solid content are calculated. Taking into account the information received, the correlation of the costs of phosphate raw material pulp and sulfuric acid is corrected, which provides resource-saving technology. Thus, the proposed control method provides a reduction in water-insoluble losses of phosphorus pentoxide in the process of extraction and crystal formation, a reduction in water-soluble losses of phosphorus pentoxide with phosphogypsum in the process of filtration and washing of sediment, an increase in the performance of the filtration unit, and a decrease in total losses phosphorus thioxide and increase the productivity of production of EPA. The drawing shows a scheme for implementing a method for automatically controlling the operation mode of a cascade of two extractors, the first of which is under vacuum. Sensors 1-5 are designed to measure the flow rates of sulfuric acid, phosphate raw material pulp, circulating solution, reaction pulp supplied by filtration, ammonium sulfate, sensor 6 for measuring the level of pulp H in the second extractor, sensor 7 for measuring the temperature of reactionary pulp t in the first extractor, sensors 8–11 for measuring the main operating parameters of the extraction process, namely, the ratio of the liquid and solid phases of the reaction pulp (g / t), the concentration of excess sulfuric acid, uiPHaSO. extractor, the concentration of excess sulfuric acid. ° ORO extractor and con-o. concentration of sulfate ions Cc, 04. about the second extractor. The 12th sensors serve to measure the density of ammonium sulfate, sulfuric acid, and phosphate raw materials pulp, respectively. Executive mechanisms 15–20 are designed to change the flow rates of sulfuric acid, phosphate raw material pulp, working solution, reaction pulp for filtration, from ammonium fat and ammonia values and vacuum in extractor 1, respectively. Control blocks 21–26 are used to adjust respectively sulfuric acid, the temperature of the reaction pulp in extractor I, the level of pulp in extractor IIJ, the ratio of the quantities of liquid and solid phases of the reaction pulp in extractor: III consumption of pulp of phosphate raw material, consumption of ammonium sulfate. The control system shown in the drawing also includes a computer-based control computer system (UCM), which includes software blocks 27-32. Blocks 2729 are designed to verify the reliability of information on the concentration of excess sulfuric acid in the first and second extractors, the concentration of sulOAT ions in the second extractor. Blocks 30, 31 are used to calculate the current concentration of sulfate ions in the first and second extractors. Block 32 is designed to generate differentiated control actions for pulp flow. The way of reporting is as follows. Sulfuric acid consumption is measured by sensor 1 and maintained at a predetermined level using regulator 21 by varying the consumption of sulfuric acid by acting on the actuator 15. The temperature of the reaction slurry in extractor I is measured by sensor 7 and maintained by regulator 22 by changing the magnitude of vacuum in the extractor I by acting on the actuator 20. The pulp level in extractor II is measured by sensor 6 and, with the regulator 23, maintains the measured sensor, depending on the flow rate of the reaction slurry, com 4 and level values by changing the flow rate of the reaction pulp fed to filtration by acting on the actuator 18 "The ratio of the amounts of liquid and solid to the phase of the reaction pulp in extractor II is measured by sensor 8 and maintained by controller 2 depending on the flow rate of the working solution, measured by sensor 3, and the ratio of the liquid and solid phases in the reaction slurry by changing the flow rate of the working solution by acting on the additional mechanism 17. The consumption of ammonium sulfate is measured by sensor 5 and Regulatory unit 26 depending on ammonium sulphate consumption, sulfuric acid consumption measured by sensor I, ammonium sulfate consumption change by acting on the actuator 19o Raw material slurry consumption is measured by sensor II and maintained at a predetermined level using slurry consumption regulator 25 by acting on the actuator 1b. The task of the controller 25 generates a control output unit 32, which is part of the control unit. The operation unit of the unit 32, as compared with the known method, additionally provides for periodic correction of the pulp consumption by the concentration of excess sulfuric acid in the second extractor Cj jBH ud 10) t determined by the electrical conductivity of the pulp, according to the concentration of sulfations in the second extractor C (sensor 11 (determined by laboratory analysis, according to the concentration of sulfate ions in the 1st and 2nd extractors, determined from the mathematical divisions (blocks 30 and 31). The control algorithm additionally provides compensation for disturbing effects on the concentration of sulfuric acid (sensor 13), pulp density of phosphate raw material (sensor), and concentration of ammonium sulfate (sensor 12). The control algorithm is based on an adaptive mathematical model fundamentally taking into account the material balance of the process and including constantly updated statistical data. Blocks 27-29 form statistical samples that include the N30 number of points, respectively, for i-fc / i SaerteSO. updated at the time of entering the next laboratory analysis by dropping the oldest point in time. According to the well-known method for Cj / egfusO and SciC, the statistical sampling HPf homogeneity is checked (blocks 27, 28, for a given minimum admissible number of points, As the computer enters

an alternate CW with time indication 15

 ; .;, -:

f

.hv its selection in blocks 27-29 is a collection of statistics on the concentration of sdJl ions and both extractors corresponding in time given tW.jiaj For a given level of significance p (see example, p 0.9) and the number of degrees of freedom n determine the value of single sampling. The validation algorithm, filtering and weighing information contains the following basic steps:

A coefficient is formed that is proportional to the C й th | forehead of K mzbA & O For Kf, the following condition must be fulfilled:

 c & oV boft-3

C U56, Ng (N

i. According to formula (1) we define for n points:

IE6 LCsoJ SOjJ

Not SO

and "b

- j. (g) - t

wt, -MSG +

(.4.0. OHeS AALS.

HiSO-fP

(1) Laba & rllg i-MMK An equation is formed, which determines the relationship between the value of the laboratory analysis and the calculated value, taking into account the excess acidity in the i-th apparatus, corresponding to:

- ", -,

S ie & Ng04

values are formed:

with;

C / "s & .H2 & a lr

(7G

I

Cf. R

r "

(UЗB. | Zj HuS04)

2 | i p

C, use

ni

 HzSOVP

r de C. in

- the actual average value of excess acidity in the extractor over the time interval at the time of selection of the next laboratory analysis with their total amount equal to

H

IBD) Ha & Ov

The dependencies are constructed similarly according to the formula (3):

f (C

sor

four

yes B

1 f (C

504

bark

; In addition, the following regressive dependencies are obtained (of the form y "ah + b):

С „5е f (C мзб)

HI & OA HzSO

As a result, according to the 1st extractor, there are three statistical equations for calculating the acidity obtained by different methods, for the 2nd extractor - two. For the first reactor, the reLO & .

 Is determined

 ani

. ani a: --Jf -. h

P

5 (ag "; bs; And pt

p-: p

Finally, the criterion for checking the homogeneity of samples is formed, which is compared with the table

value:

. I

... (2)

Vmi 0 (- b

 Is determined by

addiction

 f (ct (6) which

C, vl3B L)

rieSO Ip-Nazo

has the following form:

.6th. K, g

(3)

VL, “3E. 7 IU36; ij- HaSO + P HaSO

5 results of calculations for three equal-;

I m according to the formula (2), and for the second

 reactor design values average: NONE. The final result of operation 0 of blocks 27-29 is the formation of specified ranges of excess acidity in 1 in 2 extractors for the next introduced laboratory analysis.

 FOREHEAD

In the intervals between the arrivals of the next laboratory analysis, the concentration of ions 80 in the 1st and 2nd extractors is determined in blocks 30 and 31 by a known method by constructing linear regressive dependencies of the form (y ax + b):

f (CHjB)

f (S5s6). NGZO

Block 32 of the issuance of control actions generates a control loop, torus 25 pa following

where QnaK p5dii gSDD p 2 2S (H average statistical values of the consumption of PULTS apatite concentrate (sensor 2), pulp density (sensor 14), sulfuric acid consumption (sensor 1), sulfuric acid density (sensor 13) and sulfuric acid concentration, indirectly determined

by its density,

lute ": p7" pT "„ tech

EDA; rnatL NyO- | values of sulfuric acid consumption, sulfuric acid density, pulp density of apatite concentrate, sulfuric acid concentrations,

, 15, 53 - constant coefficients obtained by deriving the dependence (} from the material balance equation,

D - the deviation of the conductivity (in) from its calculated value I

K, K-2, K 5 are empirical coefficients, taking into account, respectively, the proportion of proportional, integral and differential components in the total deviation of D.

Under the conditions of trial operation of the mathematical model on a real industrial object, the following ranges of coefficients were obtained:

2,, 0, 0.2 Ko.0.35, 1,, 8.

The following values of the coefficients are optimal: K.t. 2.8; Ka 0.28; Kg 1.3. Varying their values; It is possible to change, if necessary, the proportion of one or another component.

The deviation of the electrical conductivity D in the general case in equation (k) can be taken into account simultaneously by two excractors or only by one of them:

.a |, (1 -fb) u |

(five)

where is the deviation of the electrical conductivity in the 1st extractor;

i deviation of electrical conductivity in the 2nd extractor;

P) is a coefficient that allows to take into account the degree of influence of the electrical conductivity deviation.

(ie, the concentration of excess sulfuric acid) in each apparatus on their total otgledenie.

Coefficient P) varies in the range of 0 1.

Varya P, can be carried out according to the formula C) periodically correcting the magnitude of the controlled exposure only by the concentration of excess sulfuric acid in the 2nd extractor (at p 0) using sensor 10; only on the concentration of excess sulfuric acid in the 1st extractor (with p O on sensor 8, taking into account con1, the concentration of excess sulfuric acid in both extractors (with Oi p 1) on sensors 9, and 10 simultaneously.

Correction of the control action according to the formula () depending on the AS is made after 1 min.

In the formula (4), the periodic correction of the control action QtiQt o the concentration of sulphate ions in the second extractor Cs-L2-definite Au | 3 is also present in an implicit form.

labeled.

Magnitude. in the formula (5) represents the deviation of the current value of the electrical conductivity of the bullets; dust in the 2nd device, about / from its calculation a,

 value

 ar- f,

(6) pulp flow and implements. functional interoperability: Ib .. 1, ,, HaS04PH2J04 H2 04 connection between the control action and adjustable parameters:, Teit t x K, + K3) uJtK, jII d j tegg

Information about f / 2V comes continuously from sensor 10, and is periodically corrected by the value of the next value of the concentration of sulfate ions in the 2nd extraction torus:)

laboratory analysis (sensor 11). Correction is made at the time of

Z.

Where are the Strengths determined by the tables of the 4apt mathematical model (blocks 30 and 31), the calculated optimum concentration of sulfation ions in the i-M extractor that needs to be maintained is the concentration of sulfate I & ions in the 2nd ektraktor, laboratory-controlled, n - concentration of hits (taking into account the closest prehistory) T, o into this zone of the regulated range of variation of Su (the range of variation Cjo is conventionally divided into 5 zones and the value n allows to differentiate the control value quafc depending on the number of hits in the zone); 1 - coefficient taking into account the degree of distance C from the zone of optimal process management, the value of ui allows differentiating the magnitude of the control action QttQt. depending on the walk of the cSs, in the concave zone, the values are individual for each zone and determined by an expert on an industrial facility: Q.5i о; (((;

70875918

arrival of the analysis with an interval of 2 hours, Functional relationship between pr (and therefore, in (the end result, and Q and value is empiricostatistical in nature and in the mathematical model of the proposed method of control; and represented by the following control for the i-th tractor:

n +.

one

Claims (2)

(7). K is a statistical coefficient representing the specific change in j concentration of sulfations per unit change of electrically /: ... condition, K is determined by post-sampling samples and equal to the ratio of dispersions: -Ssfil ii When operating the model on a real object, K j takes values in the range 1, 6. Statistical data for. Choice SO AOfe f-2. are preliminarily checked for authenticity, filtered and weighed in blocks 29, 27, 28. Thus, functional correlation (7) periodically corrects jp and, therefore, L (formulas (6), (5j, and ultimately - correction ((atc, (formula) on the concentration of sulfations in the 2nd extractor, determined by laboratory analysis. In this case, each newly obtained laboratory analysis is checked for reliability on the basis of statistical data on the state of the scientific-research institutes of the process in the interval between ana- sis. Correction controlThe effect of QflAt on the concentration of sulfation, determined according to the mathematical model, is also carried out in accordance with the functional dependence (7), where the input / h.it is periodically calculated in blocks 30 and 31, the Q value. The calculation is made at the time of the next laboratory analysis concentration of sulphate ions (after 2 hours); determined by a tabular mathematical model developed taking into account the requirements of the technological regulations for changing the concentration of sulphate ions, analyzing the experimental data Ota real industrial cascade decomposition voltage. The existing model makes it possible to optimize the process of regulating the concentration of sulfides, at-ions, and the optimal value of C is chosen in accordance with the finding of the current one of the 5 zones of the prescribed range, taking into account the history of and optimal process requirements. Thus, the correction of the phosphate raw material pulp consumption according to the concentrations of sulfate ions, determined by laboratory methods and according to the mathematical model, takes place simultaneously with an interval of 2 hours, and the correction by the concentration of excess sulfuric acid is almost continuously (every minute) in the interval between analyzes based on information from the analog sensor 10. For the implementation of the control method, statistical functional dependences of the concentrations of ammonium sulphate and ammonium sulfate are used, and ednestatisticheskoe receptacle chenie pulp density apatite concentrate, the current value and the pulp density to sulfuric slots. The relationship between the concentration of sulfuric acid ScdS and its density HaSOu 13) in the mathematical model of the proposed control method is presented in the form of a 6th degree interpolation polynomial that implements the known reference data Polynom has the following coefficients AO 31.6i; A 7.28; A2 23, AJ-i8ji; A4 -1.95; A -7.52 AB 5.22 - and allows you to determine the concentration of sulfuric acid (in the count on monohydrate) in the range of 69 920, with a possible density fluctuation of 1.60-1.83 t / m. Compensation of disturbing influences on the concentration of sulfuric acid occurs in accordance with the functional dependence C), which includes its average statistical value of OIOD. and the current value of C, Ammonium Sulphate Concentration. Sel is determined from a tabular model containing known reference data, the input variables for which are the temperature and density of ammonium sulphate in ... (sensor 12). I The calculation of Qptj, the formula (k) is carried out from the conditions of material balance and the need to maintain a predetermined ratio () between the consumption of sulfate-containing reagents (RC29o QCA / The value of s, is determined by the requirements of the three-technology regime for the concentration of sulfate ions, and ammonium sulfate is entered to preserve sulfuric acid; in the proposed control method, the independent variable, which determines the load on the decomposition cascade, is the consumption of sulphate-containing reagents (c), equivalent to from o (bff, In the material balance equation, the average statistical concentration of ammonium sulfate is taken into account and its fluctuations are compensated for by adjusting the balance equation after 1 hour at the time of updating the statistics. The compensation for fluctuations in the density of the pulp of the apatite concentrate (sensor 1) is taken into account directly in dependence (), which includes the current K. Average statistical density of the pulp of phosphate raw materials: Using the proposed method of automatic control of the operating mode of the cascade of two extractions Compared to the known phosphoric acid pulp from the production of phosphoric acid, it increases the productivity of EPA production by increasing the filtration unit's performance due to the formation of 2.1 Phosphogypsum sludge with good filtering properties, increasing the commercial extraction of phosphorus pentoxide by reducing the water-insoluble losses in the extraction process and reducing the water-soluble losses with oostogips) and optimal conditions for the extraction and crystal formation of phosphogypsum, saving the consumption of sulfuric acid, apatite raw materials, energy resources, materials The invention 1. Method for automatically controlling the operation mode of the cascade of two extractors in the production of phosphoric acid extraction pulp from phosphate raw material pulp, including controlling the concentration of excess sulfuric acid (sulfate - :; ions) maintaining a constant ratio of the consumption of sulfuric acid and phosphate raw materials with a correction of their ratio of the content of sulfate ions in the first extractor, regulation of the temperature of the reaction slurry in the first extractor by changing the pressure value, adjusting the slurry level in the BTOPCIM 59 extractor by changing the flow rate of the reaction slurry supplied on filtration, regulation of quantities of liquid and solid phases in the reaction pulp of the cascade by changing the supply of working solution to the first extractor, which differs We note that, in order to increase the filtration process productivity and reduce the total losses of phosphorus pentoxide, the concentrations of excess acid sulphate and sulfate ions in the second extractor are additionally measured, the concentration of sulfate ions in the first and second extractors is predicted, and Periodic correction of the ratio of the consumption of sulfuric acid and the phosphate raw material was carried out. 2. The method according to claim 1, about tl and h and y and the fact that, in order to save reagents, raw materials and energy, the pulp density of the phosphate raw material and the concentration of ammonium sulfate at the inlet of the extractors cascade are also measured and values and changes in the concentration of sulfuric acid corrected the ratio of the flow rate of pulp and sulfuric acid by changing the flow rate of the pulp. Sulfate 5 10 ammonium Reomtsionma pu bona fpujibfftpaatsiyu .. E / fCfnpa frfOp - jf