SU1414461A1 - Method of automatic controlling of single-stage cycle of wet grinding - Google Patents

Abstract

The invention relates to the field of automatic control of technological enrichment processes, in particular, to methods of automatic control of wet grinding processes in a ball mill operating in a closed nickel with a spiral classifier. It can be used at concentrating plants of non-ferrous and ferrous metallurgy. The invention allows to improve the quality of UPNa enrichment (L

Description

14

gov. To achieve this goal, stabilize the ore consumption, stabilize the ore-water-to-mill ratio by changing the water consumption in the mill, stabilize the pulp density in the classifier discharge by changing the water consumption to the classifier discharge, adjust the water consumption to the classifier, and change the additional water consumption to the mill supplied through the discharge mouth inside the mill to the end of the grinding chamber, depending on the magnitude of the difference between the set and measured values of the mass flow rate of the coarse fraction unmilled ore through the discharge neck of the mill. The specified value of the ore consumption in the mill is measured at the output of the ratio of the ore consumption to the total consumption of the main and additional water in the mill for the limit set values. A device that implements this method contains a sensor 1 and an ore consumption adjuster 2, an ore consumption regulator 3, a thyristor converter control unit 4, a motor 6, a conveyor-feeder 7, a mill 8, a classifier 9, water consumption sensors 10-12, actuators mechanisms 13 - 15, adjustable valves 16 - 18, regulator 19 of ore-water ratio, regulators 20 and 21 of water flow, regulator 22 of correction, ratio setting 23, computational blocks 24 and 25, pulp density sensor 27, subtraction block 28 , elements I 29 - 31, threshold elements 32 - 36, setters 37 - 40 ry signals, unit 41 pulp density.

the keys 42 and 43, the blocks 44 - 47 of the comparison, the block 48 of the addition, the inverter 49. 1 Il.

one

The invention relates to the field of automatic control of technological enrichment processes, in particular, to methods of automatic control of wet grinding processes in a ball mill operating in a closed loop with a spiral classifier, and can be used in concentrating plants of nonferrous and ferrous metallurgy, having similar cycles of raw material processing.

The aim of the invention is to improve the quality of control.

The essence of the method of automatic control of a single-stage wet grinding cycle is the separate regulation of the intramill load density in the grinding zones and the discharge zone, the internal core density in the grinding zone being selected to be maximum and maintained by the ratio between ore and water, and the density of the intrameel - the charge load in the discharge zone is regulated by maintaining the flow of additional water through the discharge zone to the end of the crushed chamber at the value at which dit

to

20

25

maximum precipitation of large amounts of substandard lumps of unground ore. At the same time, the change in consumption of additional water is made only when the weight consumption parameter of unground ore exceeds the minimum or maximum value, which is characterized by a sharp change in the type of ore being processed to grinding, to compensate for which an additional correction of the specified ore consumption is introduced. At the same time, to compensate for possible changes in the density of the pulp in the discharge of the classifier, the flow rate of the flow into the classifier's discharge is changed by an amount equal, but with the opposite sign, to the magnitude of the change in the flow rate of additional water in the discharge zone of the mill. This avoids possible fluctuations in the density and size of the finished product in the discharge of the classifier, maximizing the cycle performance over the newly formed finished class.

The drawing shows a block diagram of a system for implementing the method.

The system contains the sensor J and the setting unit 2 ore consumption, regulator -3

course of ore, block 4 of control by thyristor converter 5, motor 6, conveyor-feeder 7, mill 8, classifier 9, sensors 10–12 p water drawers, ISIS actuators, adjustable valves 16–18, regulator 19 ratio of ore - water, water consumption controllers 20 and 21, correction controller 22, ratio setting unit 23, computing units 24 and 25, coarse fraction weighing flow sensor 26 of unground ore, pulp density sensor 27, subtraction unit 28, And 29-31 elements, threshold elements 32-36,: adverschik 37-40 reference signals, the density 41 peak Hulpe, keys 42 m 43 47 n-4A comparing unit 48 r-io: -., eHiin iiger- and 49 Torr.

Management of phlegm sputum about grinding ocyiuecTi. iHioT, impact on ore consumption, 5% and additional water per mill and node 1 consumption in the classifier in a simple way. The optimum filling and density of the pulp in the grinding zone is maintained by stabilizing the average grinding setting; capacity and fineness of ore value of the stabilization circuit. When processing the medium type of ore from the output of the regulator 22, the correction of the target signal is not present, regulator 3 processes random inconsistencies between the target and the current ore consumption from setpoint 2 and sensor 1. At the same time, the ratio of ore to water is stabilized. Comparison in the regulator 19 of the current ratio of ore consumption from sensor 1 to the flow of primary water into the mill from sensor 10 is the water consumption and the specified ratio from the setting device 23. The controller 19 through the actuator 13 controls the valve) 6, drive The flow rate of the main water in the mill to the specified ratio. The output cycle product is stabilized by adjusting the density of the pulp in the discharge of the classifier 9, maintaining the pulp density set by setter 41, changing the flow rate of the discharge of the classifier 9 by the actuator 15 and valve 18, and controlling the actuator 21 to optimally adjust the mismatch between water consumption

a a

Wj in the sink classifier, get 4461

time at the output of the computing unit 25, and the current W from the sensor 12 water flow.

5 The predetermined water flow rate W is determined in the computing unit 25 by the following expression:

wr (t)

J (t) -xW, (t) Q (t-r,) La. ()

- w, (,) - w, (,) -T,) wjt- r) + Wj (t-Tpj

(one)

where p (t) and 5 (t)

0

five

the current and predetermined density of the pulp in the discharge of the classifier at the moment of time t, at which the controlling effect on the change of water flow in the discharge of the classifier is determined;

Q (t-,)

- the measured value of ore consumption in the mill at the moment of time (t-C,), where G is the lag in the channel;

W (t-Cj) is the flow rate of the main water in the mill at the moment of time (t-T), delayed along channel f,

) - water consumption into the discharge of the classifier at the moment of time (t-T), where T is the delay in the W channel - f;

WjCt-T) - discharge additional water through the discharge opening into the inside of the mill at the moment of time (t-Tj), where C, is the transmission through the channel W f.

The magnitudes of the measured and calculated parameters are in relation to Г i T LJ it and depend on the design features and the type of equipment installed, are determined during the initial setup - system setup, and can be refined in the course of operation, adapting to change the dynamics of the object of regulation.

In this case, the control action from the controller 21 is formed in proportion to the value of

the ratio T of ore consumption Q to the sum of consumption of the main W, and the additional

Wj water to the mill, i.e.

Mich

Make

Max W, + W,

. (G-)

cT-f

, (3)

3ag

dW - W (t) - W (t)

, Ass

In which, due to the fact that W is determined by the extrusion (1), the static static transmission coefficients of the disturbance channels, namely: W f,,, and the changing type of ore are automatically taken into account by estimating and calculating the specific weight of solid phases in the discharge of the classifier by the parameters of the process and its substitution into expression (1).

The weight quantity of the coarse fraction of unground ore, i.e. the output of scrap from the mill depends on the properties of the ore, the grinding mode, the state of the equipment and is measured by a sensor 26, for example, an electromechanical counter of the output of the scrap can be used.

Research has established that there are normal limits to the variation of the scrap output parameter from D to °. Within this range, this parameter is subject to random disturbances and no correction for the control action is needed.

When the value of scrap output varies from up to the maximum allowable value S, it is necessary to change the density of intramill loading in the unloading zone in the direction of decreasing it in order to more intensively precipitate large classes and prevent their excessive exit through the discharge opening. The limit of variation of this density is limited by the value of the maximum allowable dilution of the pulp, equal to the density of the pulp in the discharge of the classifier f. The maximum allowable dilution of the pulp corresponds to the maximum value

Q where Wj is equal to water consumption

Wj into the discharge of the classifier necessary to achieve a given pulp density f when grinding ore with a specific weight a, ore consumption Q and

15 given the ratio of ore - water, (2) i.e. known consumption of main water

W in the mill. Thus, it is determined from the balance control for the density of the pulp in the discharge - 20 classifier under the condition that W O.

When reducing the scrap yield less than the minimum value for q, it is necessary to reduce the flow of additional water W to the discharge area of the mill. The minimum allowable dilution of the pulp in the discharge zone corresponds to the maximum ratio Q / () provided

30 that Wj Oh, i.e. ore - water into the mill

"Max

0 W.

35

mime

40

The value of T is set by the setting device 40, and by the setting device 23,

If no change in the additional water consumption Wj can compensate for the change in ore type, t, e, enter the value in the allowable range, where

45

minaop

SK S, S,

(five)

50

it is necessary to carry out the correction of the specified ore consumption in the mill, and with S S and Wj O it is necessary to increase the task for ore consumption, and

with S .. S.,

Io-ks

AND

Q

NIN

Do not - W3

bypass to reduce the task of ore consumption,

55 If, after the introduction of the indicated corrections, the object is brought into the region of normal operation defined by expression (5), then Q, W, Wj and / on new

 1Д4616

the ratio T of ore consumption Q to the sum of consumption of the main W, and the additional

Wj water to the mill, i.e.

Max W, + W,

. (G-)

cT-f

, (3)

Make

j

"Max

0 W.

mime

The value of T is set by the setting device 40, and by the setting device 23,

If no change in the additional water consumption Wj can compensate for the change in ore type, t, e, enter the value in the allowable range, where

45

minaop

SK S, S,

(five)

it is necessary to carry out the correction of the specified ore consumption in the mill, and with S S and Wj O it is necessary to increase the task for ore consumption, and

with S .. S.,

Io-ks

AND

Q

NIN

Do not - W3

bypass to reduce the task of ore consumption,

If, after the introduction of these corrections, the object is brought into the region of normal operation, defined by expression (5), then Q, W, Wj and / on new ones are stabilized.

71

corrected values before the arrival of the following perturbations. If de specified correction is not. is received through the time of transition to the area of normal situations (5), the correction is repeated in magnitude and sign in the same direction.

The specified correction circuit works in a way). The first inputs of the blocks 44 - 46 of the comparison are fed from the setters 37-39, and to the second inputs - the signal from the sensor 26 of the weight flow of the coarse fraction S, and the sets 37-39 set the values of sr sf

At the output of the threshold elements 33-36, a signal of logical 1 is formed, if at its input a signal is large or equal to zero. In blocks 44–47 comparisons, the differences are determined.

min „max

 ,, - - 5, SK R I rriM and and riT

-j, t-1 sootnegstpenpo,

mi /

When S i S, L O at the output of the element 33, the signal logical 1 appears, which enters I element 29 and 42, opening it and opening it.

solving the passage of the value of b, bc from the output of block 44 by comparison to block 48 and further to water flow controller 20, which through mechanism 14 and valve 17 reduces water flow Wj to the discharge zone of mill 8,

When water consumption W decreases to the minimum level, threshold element 32 triggers, i.e. at W 0, and at its output a signal of logical 1 is generated, arriving at the second input of element I. If the signals of logical 1 are at both inputs of the element And, the signal of logical 1 is also output at its output at the input of the task correction controller 22, which incrementally increases by 10% the value of the task from the setting device 2 ore consumption. All other stabilization circuits work as before. Element And 29 is introduced to prevent false triggering of the correction contour during a short-term change in the type of ore being processed. ,

max "mo-x

When S S value S.

S 0, at the output of the threshold element 34 a logical signal O is generated, arriving at the element 31 and the inverter 49, at the output of which a signal 1 is generated.

18

At maximum liquefaction, when T i T flows from the computing unit 24, the value at the output of the block 47T-T 0ina to the output of the threshold element 36 produces a logical 1 signal, postings to the second input of the And 30 element. If there are logical 1 signals on both of the latter, then from its output, the logical 1 signal is fed to the second input of the task correction regulator 22 for a stepwise reduction of the reference from the unit 2 for ore consumption.

When condition (5) is fulfilled, the outputs of the comparison units contain signals greater than zero, therefore, the output of the threshold elements 34 and 35 are logical 1 signals, the I input, the logical I, which opens the key 43 at the output, skips to the second input of the 4B layer - addition, the signal from comparison unit 46, equal to S - S, arriving at

an increase in the consumption of additional water Wj through the regulator 20 and a decrease in the p-approach of water to the drain of the classifier through the regulator 21.

Thus, in all modes

It maximizes the cycle throughput of the newly formed finished product while minimizing the dispersion of density fluctuations and preventing emergency situations. All correction signals come with coefficients that are determined empirically, and the percentage of the fraction of the controlling parameters in the formation of control actions is taken into account.

Using the proposed method will allow to achieve an increase in productivity for the newly formed finished product by 2.5-3% with

at the same time reducing the dispersion of the size grain by 30%.

Claims (1)

Invention Formula A method of automatic control of a single-stage wet grinding cycle, including measuring ore and water consumption in a mill, measuring water consumption in a classifier discharge, measuring pulp density in a classifier discharge, measuring the weight consumption of a large fraction of unground ore through the discharge neck of the mill, stabilizing the ore consumption at a given value, stabilization of the ratio of ore to water in the mill at a given value by changing the flow rate of water in the mill, stabilizing the density of the pulp in the discharge of the classifier at a given value, by changing the flow rate of water into the drain of the classifier, about tl and h and H1 and so that in order to improve the quality of control, the flow of additional water supplied through the discharge mouth inside the mill to the end of the crushed chamber is measured, changing the flow of additional water into the mill is adjusted, the flow of water into the classifier is adjusted, the set value of the ore consumption is changed, the total ore consumption is calculated to the total flow of main and additional water into the mill, and 1446110 Correction of water consumption in the classifier and the change in the flow rate of additional water in the mill is carried out, depending on the magnitude of the difference between the set and measured values of the weight flow of the coarse fraction of unground ore, through the discharge neck of the mill; The 10 values of ore consumption per mill are carried out at the output of the computational ratio of ore consumption to the total consumption of primary and additional water in the mill for the maximum 15 Mbie values, while decreasing this ratio less than the minimum set value reduces the specified ore, the consumption of ore consumption in the mill, and when the value of this ratio reaches its maximum value, the specified value of ore consumption is increased into the mill.