SU1715871A1 - Method of control of pulp separation process - Google Patents

Abstract

The invention relates to non-ferrous metallurgy, in particular to hydrometallurgists. The invention relates to non-ferrous metallurgy, in particular to hydrometallurgical processes of processing ores and concentrates, and can be used to control the processes of autoclave technology for the processing of polymetallic raw materials. The aim of the invention is to reduce the consumption of reagents. Figure 1 shows a block diagram of one of the possible options for implementing the control method; figure 2 - the dependence of the potential of the electrode from the consumption of reagents. From the electrode station 2 installed in the reactor 1, a signal proportional to the potential of the indicator electrode enters unit 3, in which the average value of the fluctuation amplitude (AFP) is calculated during the Dm time set on the commander 4. The signal proportional to the APF is stored at block 5 in the first interval, at block 6 in the second interval. In block 7, the difference between the signals from blocks 5 and 6 is calculated; signal proportional to the processing of pyrrhotite concentrates. The purpose of the invention is to reduce the specific consumption of reagents. The essence of the method lies in the fact that the management of hydrometallurgical processes is proposed by the magnitude of the amplitude of the potential of the indicator electrode (AFP), and the sign and difference of the AFP at the i-th and (M) -th time intervals are determined, the sign of the change in reagent consumption by i is determined - m and (M) - m intervals and if the signs of the differences between the AFP and the consumption of reagents coincide, they increase, and if they do not match, they decrease the consumption of the reagent directly proportional to the value of the difference between the AFP. 2 Il. The value of the difference obtained enters the regulator 8, the sign of the difference obtained is in block 9. Similarly, the signal proportional to the consumption of reagent q from the indicator 10 installed on the reagent supply line to reactor 1 is integrated in block 11, then stored in blocks 12 and 13 - on the first time interval Ati in block 12, on the second - block 13. The difference of signals from blocks 12 and 13 is calculated in block 14, the sign of the difference goes to block 9. In block 9, signs (AFP2-AFP1) and (q2- qi) are compared: with the same signs, the controller 8 receives a signal, allowing conductive increase the flow rate h reactant at different - smaller. In controller 9, a signal is generated that is proportional to the difference (AFP2-AFGI), received from block 7, fed to the actuator 15, which changes the flow rate of the reactant in reactor 1. Then the procedure is repeated, and at the beginning of the third time interval, the signals in block 6 and 13 the new arrivals from blocks 3 and 10 are erased and remembered.

Description

The essence of the invention is as follows.

For a variety of hydrometallurgical separation processes based on the interaction of pulp components with reagents in stirred reactors (this interaction leads to a change in the potential of the indicator electrode), the dependence of the AFP on the specific consumption of reactants has an extremum at the inflection point of the curve, which represents the dependence of the potential of the indicator electrode from the consumption of reagents. For example, as shown in Fig. 2, the amplitude of the ORP fluctuations of the platinum-silver-chloride electrode pair on the steep part of the curve increases as you approach the inflection point, and decreases after the inflection point. Under the influence of uncontrolled influences, the location of the curve in the coordinates of the consumption of reagent - ORP can vary, the magnitude of fluctuation amplitude in the region of its extreme value (curves A, B, C in Fig. 2) can also change. However, in all these cases, the extremum of the amplitude of fluctuations coincides with the inflection point of the reagent consumption curve — the potential of the indicator electrode. This is usually the area of optimal modes: to the left of this area, the degree of separation deteriorates; on the right, the quality of the separation products decreases and the specific consumption of reagents increases.

Management are as follows.

At the initial moment of time in an arbitrary direction, the consumption of the reagent is changed by the time of Fm. The flow rate qi is memorized in block 13, the value of AFP1 recorded at this consumption of reagent is memorized in block 6. After the expiration of Au for the period At2, the reagent consumption changes in the opposite direction, for example, until the previous value of q is restored. New values of qa and AFPa, obtained after the time At2, are memorized in blocks 12 and 5, respectively. Then in block 7 the value and sign of the difference (AFP2-AFP1) are found, in block 14 - the sign of the difference (q2-qi); the signs are matched in block 9 and, depending on the combination of the symbols in block 8, they form a signal allowing to increase (same signs) or reduce (different signs) the consumption of the reagent for the subsequent time interval Ata by acting on the valve 15 or 16.

Next, the procedure is repeated. At the next (third) step of controlling the values of the AFPT and qi are forgotten, the values of the AFPZ and

qs.

The synchronization of the operation of the blocks is provided by the controller 4, on which the duration of the interval ti is set.

Below are the results of the comparative tests according to the invention and the prototype.

The method was applied to control the disintegration process of the pulp of the sulfur sulfide material (CCM).

The process of disintegration (separation) of sulfur and sulphides is intended for the separation of elemental sulfur from sulphides with the aim of subsequent flotation of disintegrated pulp with the release of sulphide (SP) and sulfur (SC) products. The content of elemental sulfur in the joint venture should not exceed 5%, in the UK not less than 70%. The dissociation of sulfur and sulfides is achieved by treatment of pulp SSM in reactors with stirring at a temperature higher than the melting point of elemental sulfur in the presence of sulfidione in the liquid phase of the pulp. The controlling effect is the sodium sulfide absorption. The adjustable parameter is the value of the ratio Li / A q under the control of the prototype; AFP - when controlled in accordance with the invention. The quality assessment of the control is based on the flotation indices (composition of the SP and SC, extraction of nickel in the SP and elemental sulfur in the SC), as well as the specific consumption of the reagent, kg / t SMS. The distribution of the total amount of sodium sulphide fed to the reactors (q No. 2 s) is kept constant both in the prototype control and in the control in accordance with the invention. The composition of solid SSM, which arrived for disintegration during the test period, practically did not change: the nickel content was 4.95-5.43%; elemental sulfur is 35–41% (nickel is on average 5.18%, sulfur is 38%). Flotation lead in constant mode. ORP was controlled at the disintegration outlet. Electrodes - platinum - chlorine silver.

The quality of management is assessed by the following indicators: the consumption of sodium sulphide for processing tons of CCM, kg / t (q№2S); Nickel content (Ni) and elemental sulfur Sen0 in SP%, extraction of nickel in SP (; Ni),%; the content of elemental sulfur in the SC (5SK °),%; extraction of elemental sulfur in SC (ijs),%; the deviation (minimum and maximum) of each of the listed indicators from the average for the time of the test value.

Experiments 1-5 (Table 1) with a duration of 8 hours each were carried out by adjusting the consumption of sodium sulfide in accordance with the prototype. According to the normal operation data, it has been pre-established that the best indicators are obtained when

A ORP / A q Na2s 12 mV / t m.

For the first 15 minutes, the consumption of sodium sulphate was increased by 1 kg / t SMS. After 15 min, LOPP / Aqi is determined and at (OBn / Aqi-12) 0 is increased, and at (AOWP / Aq 1-12) 0, the consumption of sodium sulphide is reduced in proportion to the difference obtained. The dynamics of control are shown in Table 3 — the first 3 hours of experiment 1. Here, the quality of control is controlled by the content of sulfide ion in the liquid phase of the pulp after disintegration (before flotation). ,

Experiments 6-10 were carried out to confirm the expediency of applying the invention. Pre-consumption of sodium sulfide is changed every 8 hours, while fixing the value of the AFP. The points corresponding to the numbers of experiments are shown on the curve of FIG. 2 (curve A). The control dynamics is shown in Table 2 — the first 6. h of experiment 8. Experiment 11 was conducted 5 days after conducting a series of experiments 1-10, the duration of the experiment was 24 h.

As can be seen from the comparison of the data presented in Table 1, the control according to the invention makes it possible to increase the recovery of nickel to sulfide and elemental sulfur to sulfur products by 0.2 and 0.3%, respectively, while reducing the specific consumption of sodium sulfide by 0.4 kg / t CCM compared with the indicators obtained by the prototype process control. And from the comparison of the data given in Tables 2 and 3, it follows that the quality of control according to the invention is significantly higher than that of the prototype: deviations of the controlled pair,

meters from the average value of about 5 times less.

Calculations have shown that the introduction of the control method for the autoclave method of processing pyrrhotite concentrates will, with a conditional productivity of 250,000 tons per year of sulfur sulfide material, provide an economic effect by reducing the specific consumption of sodium sulphide and increasing the recovery of nickel and elemental sulfur.

Claims (1)

Invention Formula The method of controlling the separation process of the pulp components mainly in the stirred reactor, including controlling the specific consumption of reagents and monitoring the parameters of the ionic composition of the liquid phase of the pulp according to the potential of the indicator electrode, so that, in order to reduce the specific consumption of reagents, the mean value of the amplitude of the fluctuation of the potential of the indicator electrode (AFP) is additionally measured at two consecutive time intervals of the duration specified by the technology, determined in The magnitude and sign of the difference between the average AFP at the previous and subsequent time intervals determine the sign of the change in reagent consumption at the subsequent time interval compared to the previous interval and when the signs of the difference between the average AFP value and the reagent cost coincide, the reagent consumption is reduced by the subsequent interval time is directly proportional to the magnitude of the difference in the average value of the AFP. Table 1 Dynamics of disintegration indicators in the management of the prototype Table 3 gsh Processed PMaP (for flotation) 01 / 8.7 CV-500 35W45SO Specific consumption of sulfur but / at 50