SU983050A1 - Method of controlling preparation of two-component bauxide sintering charge - Google Patents

Description

component bauxite sintering D1, including measuring the density of soda pulp prepared from saturated and diluted soda solutions before wet grinding with bauxite, measuring the density of the resulting mixture after grinding, and classifying, and determine the specified densities of soda pulp and mixture according to the specified caustic values moisture content of the mixture, compare them with the measured values of densities and when the measured density of soda pulp deviates from the set value, the flow ratio For the increase in density, the flow of saturated soda solution is increased, and the flow of dilute soda solution is reduced, and vice versa, and when the measured charge density deviates from the target, we determine the total flow of soda pulp for grinding, and to reduce the charge density soda pulp increase and vice versa.

The caustic ratio and moisture content of the charge is measured periodically; they are compared with given values and when the measured caustic ratio deviates from the setpoint, the density of soda pulp changes, and if the measured caustic ratio is greater than the setpoint, the setpoint density of soda pulp is reduced, and vice versa, if the measured moisture content of the charge changes from the setpoint the value of the density of the charge, and if the measured humidity is greater than the specified value, the specified value of the density of the charge is increased, and vice versa.

The conditionality of the sodooboxite sintering mixture is determined by matching its caustic ratio and humidity to specified values. The caustic ratio of the mixture is determined by the molar ratio of total alkali in it to the total content of aluminum, iron, silicon and sulfur in nepec4efe on their oxides. Soda pulp is the only source of total alkali in the mixture. In addition, with the soda pulp in the mixture enters the bulk of the water. The change in the consumption of soda pulp leads to a change in the input of total alkali into the mixture. ..However, this also changes the input of moisture. The density of soda pulp rather accurately describes the content of total alkali in it, so

as the latter is the main component. In addition, the density of soda pulp determines its moisture. Consequently, a change in the density of soda pulp leads to a change in the ratio of total alkali in it and water.

Thus, it becomes possible to cumulatively stabilize the caustic ratio of the charge and its moisture content by simultaneously varying the flow of soda pulp and its density. Periodic adjustment of tasks for the current values of the caustic ratio and humidity allows to compensate for uncontrolled disturbances.

The relationship between total alkali content and pulp soda density is described by the equations

(one)

CN A-, Tc + A ((2)

B

V / c

Us

total alkali content in

where C

N

pulp in terms of

We

moisture soda pulp,%; a, b, ao

and A are constant coefficients characterizing the statistical association of parameters (for soda pulp AI 0.98, AO -1.18, and 150.8, b. Fig. 1 shows a graphical dependence of the density of soda pulp on the total alkali content in soda pulp; Fig. 2 - dependence of the moisture of the charge on the calculated humidity; Fig. 3 is a block diagram of a system for automatically controlling the process of preparing the sodocarboxytic charge for sintering.

Graph of density versus total alkali content (Fig. 1). 5 Standard deviation from the regression line at the same time is ± 15 kg / m.

Studies have established a relationship between the width of the sintering and the complex parameter, which includes the measured values of the density of the charge and soda pulp.

W ", A2 -,

(3)

VS where Wm - moisture content of the mixture,%;

fuj is the charge density,

Aa 5Ev and Al are the constant coefficients characterizing the statistical relationship of parameters (for the sinter charge Ad -66.87; A I4it, 1; Ai 32.0; graph of the moisture content of the charge (Fig. 2). The standard deviation from the regression line is em lT81.Using information about the amount of flux and composition of bauxite and soda pulp entering the sintering mixture, one can write the equation - K., I) Гfie and the costs of wet bauxite and soda sludge for preparing the mixture, respectively, t / h and humidity of bauxite, kg / causticizing with bnost bauxite kg / feb (5) v o.6 where f-q, Cp, C, and Cg - content, and respectively. SOj in bauxite,%; a constant coefficient determined by the average content of A1202 in the raw pulp; caustic ratio of the mixture, kg / kg For the sooboxitic charge, the equation G GC QS - QC 0 is valid, - is the cost corresponding to G, but soda pulp ,. t / h and wet bauxite m3 / h. By converting equations (6) with the GC QcJe dependence, one t SAT is Wc-Tc, the density of wet bauxite, t / m. Using the dependence TsB rsO-Wg) Wg, (9) e tGs, the density of dry bauxite, s .1 t / m, re- together equations (1), (8),) get the expression 7 The set of equations ilO) and (3) represents is a mathematical model of the process of preparation of the sodaboxite sintering mixture. When using this model to control the process density of soda pulp and charge serve as controlled input parameters. The remaining members of the equations of the mathematical model are uncontrollable changes in the input parameters (y, W5), constant coefficients (A, AO,) and output parameters (k, Wu,), which determine the quality of the sintering mixture. The method is carried out as follows. The consumption of bauxite in wet grinding mills is stabilized at a level, op-. determined by a given production program. The total flow of soda pulp into the process is prepared by mixing saturated and dilute soda. Saturated soda pulp has a density above the maximum required for the process. Diluted soda pulp has a density below the minimum required for the process. Given the caustic ratio and moisture content of the mixture, using the information on the average composition of bauxite and its humidity, using a set of equations (. 3 / and (10)), the specified density values of soda ash 198 pulp are determined at the input to the process and the charge at the output of grinding and classification. The current density banners of soda pulp and charge are measured, compared with the calculated targets, and when the measured soda pulp density deviates from a given deviation, the ratio of saturated and diluted soda is changed, and when the measured density deviates and the charge from a given change the total soda ash flow and process.In parallel with controlling the composition of the charge, the current value of the caustic ratio and humidity of the charge after grinding and chemical analysis or express analysis are periodically determined by input parameters, and if the measured values deviate from the specified values, the specified values the density values of soda pulp and charge with the BlsL diagram of the automatic process control system in the preparation of the sodaboxit sinter charge for sintering contains a mill 1 wet grinding , to which bauxite is supplied through a control valve 2 Flows of saturated and diluted soda through mechanically articulated control valves 3 and A are fed to the mixer 5 and after mixing, as soda pulp, through the control valve 6 are fed to the mill 1, Sodoboxitic mixture, after classification by the size 7 is directed to sintering. The consumption of bauxite is determined by the measuring device 8. The signals from the measuring device 8 and the setting device 9 are fed to the input of the regulator 10, which produces and transmits the effect on the control valve, which stabilizes given bauxite consumption. Raft .-. The soda pulp and charge are measured by density meters 11 and 12, respectively. The composition of the charge is determined by the analyzer 13. Information about the composition of the charge, the average composition of bauxite and the caustic ratio and humidity is fed to the input of the computing device 14, in which the soda density of the pulp and charge is calculated for the current density of soda pulp and of the charge, and the tasks calculated by the computing device are fed to the inputs of the controllers 15 and 16, respectively. The controller 15 produces and transmits an effect on the articulated control valves 3 and (stabilizing the predetermined density of soda pulp from the P8 V ratio of the flows of saturated and diluted soda at the inlet of the mixer 5. Regulator 1b produces and transmits an effect on the regulating valve 6 that stabilizes the specified charge density by a change in the flow of soda soda into the process, Example: For baking, bauxite from the South Ural bauxite mine is used, characterized by the following average values of P, D6 o tonnes of units; W5 of 3 or 0.03 rel. units; t / m. The content in soda pulp entering processing is, on average, SDA 0.03-0, t / m. The coefficient L determines the molar content of A1i20 entered into the charge with a soda pulp, expressed in molar portions relative to Na, jO A..f, 2,102, and 62 are the molecular weights, respectively, and. Accept A is 0.02 rel. Units. coefficients | and conditionally constant values of y, 4W, "y, A. Equations (3) and UO) take the form W.,. , 687 (ot.ed.); (12; 6 w OS. K-MilJdl Dotn. Units). (li) 0.44L2h-0.02 Each combination of specific values -jr and corresponds to a Qg combination. K and W (Table 1, based on the joint solution of equations 12 and 13). The composition of the charge is regulated by the following; they are FTl I, 00tt0.03) relative unit. and (%, 32t 2P or 0.32 (tO, 02; relative units where K5 and the specified values of the caustic ratio and humidity of the charge, respectively. The specified values for (1 ensures only the stabilization of the following values of the densities Tc 1, t / m with technological mode by the accepted average indicators. Starting from the mass balance of mixed flows () c; § (rel. units), (15) “P where (} and Pr flow rate of saturated and diluted soda pulp, respectively, density, respectively but, saturated and broken soda pulp. The values and densities are Oh and diluted soda pool of dust 1.65 t / m gGy 1.0 t / m 3. „1 (, п /.iJ In this case, equation (15) takes the submarine fb (relative units). (16) QD 1, 5-Gs To change the density of soda pulp, the ratio of the saturated and diluted pulps Qn / Qp is varied, keeping the total consumption of soda 0 stable. About 1 -t Q p 100. The results of the operation, calculated on the basis of the equation (1b are given in Table 2, the deviation of the charge density from beyond this is presented by option 6 in the table. 1. Solving jointly the equations and (E), substituted by 03; f5 3.2; fc 1, 1.88 and setting the flow rate of bauxite GE, 80 t / h, get-rt 1GW Us 1.Avv. Q ,, variant of J1 | 2 pT J5 | b

.fc, t / m 1,520 1,520 1,5 + 9 1.58 1,5491,5i9

Tr / 55 ° 1, 1.8A25 1, 1.7801.880

 K, rel. Units 0,58 0, 1,00 1,21 1,310,86

0.32 0.32 0.31 0, 0.30

q ,, relative unit 0.28 To reduce the charge density before setting at a constant flow rate of bauxite, it is necessary to increase the consumption of soda pulp. At the same time, it is equal to, l, D - JAP .03) +0.03. 1, 8J25 - 1, 112.05. Accordingly, when the actual density of the charge is lower than the target one, in order to increase the density, it is necessary to reduce the consumption of soda sludge. If the actually measured humidity of the charge is greater than the specified one, increase its density. At the same time, the humidity of the charge decreases (variants 3 and 5 of Table 1). If the actual moisture measured is less than the target, the charge density is decreased by increasing its moisture (, variants 3 and 6 of Table 1}). The overestimation of the charge measured at the measured caustic ratio is overestimated (options 3 and i). If the practically measured caustic ratio is less than the reference, the density of the soda and pulp increases with options 3 and 2), the proposed method allows to obtain a charge from the flow without using corrective tanks Ceska respect 0.08 t / t, humidity 2.5 standard deviations at stabilization of the calculated values of density soda pulp and the charge of caustic relative humidity and charge to, about t / m and ± 1,91 respectively. error of the systems, control ± 0.02 t / / t and ± 0.6, respectively. The economic effect from the implementation of the method by increasing productivity and reducing the loss of soda and bauxite will be 100 thousand rubles. per 100 thousand tons of alumina. Table 1

Option 1

QH, m3 / h tS.OO

52.00 55.99 59.60 Qp, 52.00, 00, 01, 40 QH / QP 0.923 1.083 1.272 1.475 Tc. T / M 1.52 1.53 1.5V 1, Photo of the Invention 1. A method for controlling the preparation of a two-component bauxite sintering mixture, including measuring the density of soda pulp prepared from saturated and diluted soda solutions before wet grinding with bauxite, measuring the density of the resulting mixture after grinding and classification, characterized in that, in order to improve the quality of the charge, the specified densities of soda pulp and charge are determined by the specified values of the caustic ratio and moisture content of the charge, compared with the measurements when the measured soda ash content of the pulp deviates from the target value, the ratio of saturated and diluted soda flows changes, and to increase the density, the saturated soda solution increases and the dilute soda solution decreases, and vice versa, when the measured charge density deviates from a given change in the total flow of co.

63.99 68.00 72.00 36.01 32.00 28.00 1.777 2.126 2.571 1.56 1.57 1.58 decrease in charge density The flow of soda pulp increases and vice versa. 2. The method according to claim 1, characterized in that periodically the values of the caustic ratio and the moisture content of the charge are measured, compared with the specified values and if the measured caustic ratio deviates from the specified value, the specified value of the density of soda pulp changes, and if the measured caustic the ratio is greater than the set value, the set value of the density of soda pulp is reduced, and vice versa, and if the measured humidity of the charge deviates from the set value, the set value of the charge density is changed, and if the measured humidity is More than a given, the set value of the charge density increases, and vice versa. Sources of information taken into account in the examination 1. Production of alumina. Reference metallurgist on nonferrous metals, I., Metallurgi, 1970, p. ZO. 2. USSR author's certificate number 770155, cl. C 01 F 7/38, 1978.

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The task

/ taycfTJuvecffoio O / TtffOare i / ff

OH / X / rfOf

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ff0MC (// 7fa JJ 35 J7 E9 f / 3 ghzh / w /% ig.2

Claims (2)

Claim' 1. A method for preparing a two-component control Spekatelnye bauxite charge, comprising measuring the density * prepared from ²⁰ saturated Nogo dilute soda solution and soda pulp · before wet milling with bauxite, density measurements obtained mixture after grinding and classifying, characterized ²⁵ in that, for the purpose improving the quality of the charge, determine the set values of the densities of soda pulna and the mixture from the set values of the caustic ratio and humidity of the mixture, compare ^{30 of} them with the measured values of the densities and when the measured density of soda pulp deviates from the predetermined value, the ratio of saturated and diluted soda flows is changed, moreover, to increase the density, the flow of a saturated soda solution is increased, and the flow of a diluted soda solution is reduced, and vice versa, and when the measured density of the charge ⁴⁰ deviates from the set the total flow of soda pulp for grinding, and to reduce the density of the charge, the flow of soda pulp is increased and vice versa. 2. The method of pop. ^ characterized in that the values of the caustic ratio and moisture of the mixture are periodically measured, compared with predetermined values, and when the measured caustic ratio deviates from the set value, the set value of the soda pulp density is changed, and if the measured caustic ratio is greater than the set value, the set value of the soda pulp density is reduced, and on the contrary, and when the measured moisture content of the charge deviates from the set value, the set value of the charge density is changed, and if the measured humidity is greater than the set value, the set constant value of the charge density increases, and vice versa.