SU1680618A1 - Method of control of sulfur-containing pulp processing - Google Patents

Description

one

(21) 4740226/26 (22) 09.26.89 (46) 09.30.91, Byul. №36

(71) State Research Institute for Non-Ferrous Metals

(72) M.N. Naftal, Yu.F.Markov, A.F. Gavrilenko, S.I. Roitberg, J.I.Rozenberg, A.K.Obednin, Yu.Ya.Sukhobaevsky and V.B.Pri - bylev

(53) 66.012-52 (088.8)

(56) USSR Copyright Certificate No. 778130, cl. From 01 to 17/06, 1979.

Technological Instructions of the Elemental Sulfur Production Plant No. 1. Nadezhda Metallurgical Plant NGMK, No. TI 0401.14.109-11-16-85. Nadezhdinsk, s. 30.69, 1984.

(54) METHOD OF MANAGING THE PROCESS OF PROCESSING PULS OF SEROSULPHID MATERIAL

(57) The invention relates to the automation of technological processes in non-ferrous metallurgy, can be used to control the process of hydrometallurgical processing of sulphide concentrates. The invention relates to the automation of processes of hydrometallurgical processing of sulphide materials and can be used in non-ferrous metallurgy to control the processes of obtaining sulfur in the autoclave technology of pyrrhotine processing. concentrates.

The aim of the invention is to increase the reduction in the consumption of initial reagents and increase the degree of sulfur recovery.

The essence of the control method is as follows.

based on autoclave technology with the production of elemental sulfur and allows reducing the consumption of initial reagents and increasing the degree of sulfur extraction into the marketable material. The essence of the proposed control method is that when processing the pulp of the sulfur sulfide material by successive conditioning, flotation and sulfur melting, it was first proposed to meter the surfactant into the head reactor of the conditioning cascade depending on the difference of the current and the mass content of the surfactant sulfur in the sulfur-sulfide material, and in the second and subsequent - depending on the particle size distribution and subsequent - depending on the granule the composition of the flotation foam product, while the surfactant consumption increases when the content of particles of class (-630 + 74) µm is less than 20% and decreases when the content of particles of class +630 µm is more than 10% directly proportional to the size of the deviation of the froth product from the specified values, 1 dw., 2 tab.

When the surfactant is fed into the pulp SSM at a temperature above the melting point of elemental sulfur, two processes proceed simultaneously: the first is the crushing of the globules of the sulfide melt, the wetting of the sulfide particles that were previously in the globules volume with a solution containing the sulfide-ion, and their separation from the elemental sulfur — begins immediately after the destruction by surfactant molecules of the shell consisting of surface-diphilic sludges and stabilizer molecules; the second is a coalescence already

cl

with

about

00

about

ON 00

released from the reservation shell, but not yet completely freed from sulphide globules. The larger the globule formed in the head reactor, the more often it is necessary to crush it in the course of conditioning to completely separate the components.

It has been established experimentally that in the head reactor it is necessary to create such a surfactant concentration in order to ensure the destruction of the reservation sheath and maximum separation of sulfur and sulfides without consolidation of serosulfide globules. The amount of surfactant is introduced here so that it is sufficient only to destroy the armoring shells, i.e. the process is conducted with a surfactant deficiency. In this way, the smallest sulfur droplets are obtained, bordered by finely dispersed stabilizer slimes. Stabilizers include, for example, sulphite-cellulosic liquor used in the separation of SMS from pyrrhotite concentrate; fine iron sulfides, formed by the interaction of the hydrophilizer with iron oxides; calcium sulphates, etc. When using calcium-containing hydrophilizing reagents, the latter plays a dominant role.

In subsequent cascade reactors, the amount of surfactant necessary to remove sludge stabilizers from the surface of the newly formed sulfur droplets must be supplied, which is a necessary condition for them to merge to sizes that are most favorable for flotation and autoclave sulfur production. It has been experimentally found that these conditions sufficiently fully characterize the granulometric composition of the froth product of flotation, namely: the content of classes of particles is +630 and (-630 + 74) µm. The presence of particles of class +630 µm above a certain amount indicates excessive coarsening, which causes a decrease in sulfur recovery during flotation and a deterioration in the quality of sulphide concentrate. The reduction of particles of class (-630 + 74) µm above a certain level leads to difficulties in the smelting of sulfur from the frothy flotation product.

A block diagram of one of the possible ways to implement the proposed control method is shown in the drawing,

The control object is sequentially included operations of conditioning pulp CCM (A), flotation of conditioned pulp (B), and autoclave sulfur smelting (C). The pulp enters the head reactor of the conditioning cascade, where the hydrophilic agent and surfactant are also fed.

served in the head and subsequent reactors. Disintegrated pulp enters the flotation, where sulphide concentrate (chamber product) and foam are separated.

the product is sulfur concentrate. The latter is fed to the smelting of sulfur, where commercial sulfur is obtained (to the warehouse) and smelting tails (returned to flotation).

The control system contains sensors.

1-5 volumetric flow rate of pulp SSM, its density, density of the solution and solid pulp, the content of elemental sulfur in the SMS, block 6 for calculating the mass content of sulfur with the flow of the original pulp

SSM, surfactant flow sensor 7 to the head autoclave, block 8 for calculating the surfactant ratio — sulfur flow, block 9 comparing the current to the specified value of the specified ratio, regulator 10, actuator 11, changing the surfactant flow to the head reactor, particle content sensors 12 class +630 and (-630 + 74) µm in the froth flotation product, block 13 comparing the current values of the classes +630 and (-630 + 74) µm

with specified values, the regulator 14. the executive body 15, which regulates the supply of surfactants to the subsequent reactors.

The method is carried out as follows.

The signals from sensors 1-5 are received in block 6, at the output of which a signal is formed that is proportional to the mass flow rate of elemental sulfur from the SMS. This signal and the signal from sensor 7 in block 8

generates a signal proportional to the value of the surfactant ratio — sulfur in the SMS, which in block 9 is compared with the task, their difference enters the regulator 10, changing through the executive body 11

Surfactant to the head reactor. The signals from sensors 12, proportional to, respectively, the particle content of class +630 and (-630 + 74) µm, are compared with the tasks in comparison units 13. The error signals are fed to the controller-14, which through the actuator 15 changes the flow rate of the surfactant to the subsequent reactors of the cascade.

This control method was used in the processing of pulp of the SMS obtained

autoclave oxidative leaching of pyrrhotite concentrates,

In the first series of experiments (see Table 1), the optimal processing conditions were determined with the control using the prototype method and

proposed. The SSM in these experiments was obtained from the pyrrhotite cb-concentrate with a particle size of 81.2% of the class — 44 μm and contained,%: nickel 6.12; copper 1.42; iron 27.1; sulfur 52, incl. elementary 41.6.

The aqueous pulp of the CMB density of 1.5-1.6 t / m3 was neutralized with lime to pH 8 and pumped into the main conditioning autoclave. The latter was carried out at 122-127 ° C in the presence of a reagent-hydrophilicizer (a mixture of .SaO and No. 28) of an oil-and-hydrogen surfactant (motor fuel according to GOST 1667-68). The pulp passed through a cascade of three autoclave reactors with agitators at 196 rpm. The hydrophilic reagent was introduced into the first autoclave by a centrifugal pump in amounts that ensured the redox potential (ORP) of the conditioned pulp at a level of 460–480 mV relative to the silver-chloride electrode. This level corresponded to the consumption of hydrophilizing reagents, equal to 3.9% relative to the weight of the SMS with a CaO: Na2S ratio of 4: 1. The specified flow rate of the hydrophilizer was maintained unchanged in all experiments. Surfactants in the first (according to the prototype method) or the first and second (according to the proposed method) autoclaves were supplied with dosing pumps. After conditioning, the pulp was mixed with the tails from the smelting of sulfur, cooled to 60-70 ° C and floated in a twelve-chamber FMR-bsq machine. Flotation was carried out at a final concentration of sulfide ion in the chamber product at a level of 1-3 g / l. The frothy product was fed to the smelting of sulfur in autoclaves, where sodium sulphide was used as a reagent. Melted sulfur after separation of solid impurities entered the warehouse; smelting tails containing sulfur under sulfide and sulphides that were not fully extracted into the production layer were returned to flotation together with conditioned pulp.

The results of the experiments are given in table.1. As can be seen, with the control using the prototype method, the best results were obtained with a surfactant consumption of 0.5 and 1.0 kg / ton of SMS, respectively (experiment 8).

In table.2 compares the results of the processing of pulp SSM when managed in accordance with the prototype and the intended method. SSM was obtained from pyrrhotine concentrate with a particle size of 76.1% of particles of class 44 μm and contained,%: nickel 5.83; copper 1.42; iron 28.2; sulfur 53.6, incl. elementary 39.2. The composition is average; during the comparison, the content of elemental sulfur in the SMS ranged from 36-47%,

With the control of the prototype, the consumption of surfactants in the first autoclave was maintained at a ratio of surfactants to solid SSM equal to 1.0 kg / t CCM (experiment 3 in Table 1).

When managing the proposed method, the consumption of surfactants in the first autoclave

The concentrations were maintained depending on the content of elemental sulfur g-CCM. With the change in the last flow rate PAR corrected by

at 1 4

xi xi-i-ki (---- ai), (1)

gf

where xi - surfactant consumption in the first autoclave in the 1st time interval (, 2, ...);

gsi is the content of elemental sulfur in the SMS on the 1st time interval;

,, 0011 - proportionality coefficients.

The consumption of surfactant in the second reactor was maintained depending on the particle size distribution of the froth flotation product according to the ratio

X | X | - one

+

К2 (а2 - У i - 1 КЗ (аЗ - У | - 1

, /

) priu | - 1 10;, ъ

) 20; U

where x i - surfactant consumption in the second reactor in the 1st time interval;

at | - the content (by weight) of particles of class +630 microns in the froth flotation product,

%

for i - the same, particles of class - 630 + 74 microns;

, 07,, 10 - proportionality coefficients;

 az 20-specified particle grade -630 + 74 µm, respectively, in the froth flotation product.

The values of the coefficients ki, k2, k3 and ai

determined experimentally by the results of experiment 8 in the table. one.

The data in Table 2 are presented as averages per day. When the management of the proposed method, they are obtained

in the following way.

Under the existing surfactant supply mode (the fifth day of work in Table 2 - (I) -th time interval), the content of elemental sulfur in the SMS (gsi) was determined;

particles of classes +630 and (-620 + 74) microns in the froth product of flotation (mind and y and) and surfactant consumption (x and). The value of g i took the content of elemental sulfur in the SMS in samples taken in the last 3 hours of the interval

time (1-1). The obtained values were put in ratios (1) and (2), while x and were set equal to the consumption of surfactants in 1 and 2 autoclaves in experiment 8 (see table, 1). As a result, the values of x i and were found that kept the level constant throughout the day. The values x i,, g i, y i, characterizing the mode of operation in the i-th time interval, as well as the values of g 1 + 1 at the end of this interval, are the initial data for adjusting the SAW consumption for the next (1 + 1) -th time interval.

The duration of the time interval, equal to days, was adopted in order to obtain representative estimates of flotation and autoclave sulfur production. Sodium sulphide consumption in sulfur smelting, extraction of elemental sulfur into commercial, content of elemental sulfur in chamber (should be less than 5%) and foam (products should be more than 70%) flotation products, content of organic matter in smelted sulfur (should be less than 0.25 %). These indicators characterize the effectiveness of the proposed control method in comparison with the prototype control method.

As can be seen from the data of Table 2, with the control of the proposed method, the extraction of sulfur is about 12% higher, and the consumption of sodium sulfide is 6.5% lower than with the control of the supply of surfactants in the prototype method; better quality of final products: the content of elemental sulfur in the chamber product is lower by 1.17 abs.%, the organic content in the smelted sulfur is less than jt-ia 0.04 abs.%.

Claims (1)

Claim Method A method for controlling the processing of pulp from a sulfur sulfide material (CMS), including conditioning it in a cascade of reactors, followed by flotation of pulp and smelting sulfur from a flotation product foam, by adjusting the flow of surfactants to the conditioning reactors depending on the solid content CCM pulp, characterized in that In order to reduce the consumption of initial reagents and increase the degree of sulfur recovery, the pulp density of the CCM, the density of the solution, the content of elemental sulfur in the pulp of the CCM, and the content of particles of classes +630 and (-630 + 74) µm in the froth flotation product are measured. m consumption of pulp SSM, its density, the content of solid and elemental sulfur in the pulp SSM and the density of the solution determine the value of the mass content of elemental sulfur in the pulp SSM, calculate the ratio of the surfactant consumption in the head reactor to the value of mA total sulfur content in the pulp of the SMS, the difference between the calculated and the specified values of the specified ratio is determined and, with a positive value of this difference, is reduced, and with its negative value is increased the consumption of surfactants in the head reactor is directly proportional to the magnitude of the difference obtained; they increase the consumption of surfactants in the subsequent reactors of the cascade with the content of particles of class (-630 + 74) µm in foam flotation product less than 20% (by mass) and reduce the consumption of surfactants in the subsequent reactors of the cascade when the content of particles of class +630 µm is more than 10% (by weight) directly proportional to the deviation values measured particle content from specified target values.