DE1934645C - Process for the extraction of sulfur from acid mine water containing sulphate ions - Google Patents

Description

Sulfur converted to sulfides in the molten bath

35 will.

In a further preference, wise embodiment

The invention relates to a method for obtaining the invention is the oxide-containing slag, which is after

of sulfur from acid containing sulphate ions, the removal of the sulfur from the sulphides

Pit water. holding, withdrawn from the iron melt bath

Due to the solids in operation as well as 40 remaining, to neutralize the acidic

acid mine water discharged from closed mines is also used, and the

Mine waters result in serious slag holding in many countries with or without those in others

'Problems related to water pollution. Wise withdrawn from the acid pit water

j The acidic mine water consists of solids dried and placed in the iron ore bath

complex chemical mixtures generally introduced. The slag contains a chalk

'' Hydrogen, iron, sulphate, aluminum, calcium, amount that is sufficient to keep the acidic mines

j neutralize magnesium, sodium chloride and manganese ions in water. The emergency

Solution included. The hydrogen ion concentration agility, the neutralization of the water with a

can vary from strongly acidic to neutral. external supply with lime or with another

It. there are already numerous procedures for neutralizing agents to be carried out, which results in

j ization and for cleaning and processing results in a corresponding reduction in operating costs

j acid mine water and for the production of

Relatively clean, household and falling by-product is relatively stable

] Industry needs usable water or from where when it is dumped on a heap of waste

clean water has been suggested that this 55 forms it a hard protective crust in the ^ 'ge de

; readily introduced into the streams and rivers implementation of the lime contained therein with the

<can be. However, it has been shown that all of these atmospheric carbon dioxide, so that on the ^

'Procedure so far from the economic point of view the risk is eliminated that it is by dl ·

! were seen as unproductive, since expensive atmos always coming into contact with the rubbish heap

Plants with high operating costs are required, 60 spherical moisture to a water pollution

around the water with external supply of limestone can come.

or with another neutralizing agent. The acidic mine water can initially be mi

neutralize and neutralize the mineral components of slag containing lime and magnesia

to be eliminated from the neutralized water. As come to be that are generated in the process itself

Another disadvantage is that with these 65 the acidic Minan water can then be distilled

previously known methods generally become unstable, so that drinking water is obtained. A te

; or unwanted waste products are obtained, of the water obtained in the neutralization, d <

which occurs under the action of rain or under slag and the suspended solids will m

a slurry or with semi-dry solid sulfide is formed, in which case some of the hydrogen substances brought together from the distillation stage, sulfide is reacted with oxygen, and so sulfur and then the mixture thus obtained is obtained. Then through dries. The dried slag and the other corresponding conversion from the remaining water-lime-containing solids are then after the sulfur free in the 5 substance sulfide and sulfur dioxide Patent application P 19 15 248.8 described procedure.

drive burned. In the course of a combustion process, sulfur-containing carbon fuels can be generated during the combustion process, and a limited amount of optionally preheated, so that iron from the iron hydroxide oxygen or air under the surface of an iron io of the acidic mine water and the pyrite obtained melt baths. The carbon found in the fuel, possibly in the sulphurous carbon, is absorbed by the iron and there is material fuel, so that in this way, preferably with the air or the acid, elemental iron is continuously melted from material in such a way that Carbon monoxide corresponds dsu \ combustion vessel may be peeled off is, the then upwardly through the iron bath back 15 the slag obtained after desulfurization by flows. The sulfur contained in the fuel consists of a dry mixture of ash, is also absorbed by the molten iron - magnesium oxide, calcium hydroxide, calcium oxide and sorbed, but its reaction with the air or the other constituents and then becomes in two streams under oxygen by the presence of the chemically divided. One of these two currents can prevent more active carbon. On the surface of the neutralization step ao again fed and that of the iron molten bath is maintained a molten other stream with a portion of Wassc ^r s, the slag layer of calcareous slag, and the suspended solids from the Neutralidie two Zv serves corners /. First of all, it acts as a sationsstufe merged and on a waste Flußmittc. As a result of the reaction of the molten mixture with the lime originating from the fuel in the waste mixture obtained with the non-combustible residual substances. The second atmospheric carbon dioxide is formed over the task The fact that the lime with the from the waste site has a hard crust, that is to say, the sulfur absorbed by the molten iron will receive a hard and stable waste product,
of stable calcium sulfide reacts. In the drawings, a preferred embodiment is

When using the method according to the invention 30 shown approximately form of the invention, and contained each other Parts relating to the durrl instillation of mine water are each preserved with the same reference, dried slag and solids characters. It shows

substances lime and magnesia, which are found in appli- F i g. 1 is a schematic view of an embodiment

tion of the verbal form of the method according to the invention described above and

Procedure with the 35 F i g absorbed by the iron bath. 2 is a schematic representation of FIG

Sulfur with the formation of calcium and magnesium desulphurisation plant and the incineration plant

convert sium sulfide. In the one according to the invention from FIG. 1.

The method can be carried out in the combustion container as shown in FIGS. 1 will The sulfur located comes from two sources, sajeres mine water through a line 2 into one namely on the one hand from the i.i the iron melt bath 40 neutralization device 1 introduced into which eing: sulfur-containing carbon fuel led the water to intimate contact with the consumed and on the other hand from the originally sour slag which is brought into the neutralization mine water sulfates located, which then dried up in the device 1 via a conveyor 3 Slag and other solids are passed. The spent slag contains them are. Amongst the high carbon oxides and other compounds with An iron bath with a substance-containing substance contained Reduk lime, magnesia and ash. In this neutralization station conditions are sulfur compounds, device 1 becomes those in the acid mine specsvcise Sulphates and pyrites are reduced to sulfur, the sulphate ions in water are neutralized which then deals with the metal ions in the slag layer and not with the metal ions present in the water Sensitive lime and magnesia are combined to form 50. The neutralization reactions can be calcium sulfide connects. can be represented as follows:

The carbon q _& q -l η SO -> · CaSO + HO obtained during combustion

Gas mixture containing monoxide can then be MgO + H ^ O * -> MgSO * + H * O

collects and with additional air or oxygen ² * *

be mixed, so that the carbon monoxide 55 Depending on the given composition de <

with the oxygen with the formation of carbon- acidic mine water to be treated are except

Dioxide converts, as a result of which there is a heat build-up and some hydroxides, sulphates or other salts «

ment comes, which in turn for the invention of the aluminum, magnesium, iron and calcium;

provided drying and distillation stages in the neutralization device 1 is deposited

can be used. Then it can be done with the neutralization device 1

Carbon dioxide and the other gases without exposure to any commercially available contacts

Acting risk of air pollution in the outside air direction for liquids and solids, ii

be derived. The from the surface of the iron of it to an intimate contact between the mess

bath continuously discharged slag granulates mine water and the slag comes,

on contact with air and water. 65 This becomes new from the neutralization device 1

The extraction of elemental sulfur from the neutralized water and the solid suspended in it

Sulphides in the slag can be pumped into the settling tank 4 by means of substances. This deposition

Settlement is done with water, so that the hydrogen tank 4 must be large enough to neutralize it

To absorb ized water long enough so that the fuel contained in the molten iron bath and the insoluble ash constituents and some absorbed sulfur are converted. These components of the precipitated entrained solids are in the can settle together with the As: he and other Verbin containers. These settled solids are fertilized in the form of slag from the incineration plant and then continuously drawn off via a line 5 to 5 system 13 via a descent channel 15, which they are drawn off from the settling tank 4. A part of this brings down to the desulphurisation facility 16. The molten iron produced in the relocated solids is then extracted from the line 5 incineration plant, is again withdrawn through a line 6, withdrawn through the line 24,
which they are funded to the waste disposal site. The remaining solids also borrowed in the incineration plant 13 then arrive in carbon monoxide produced with nitrogen and the drying device 7. Other gases are discharged via line 17.

The neutralized water and part of the carbon monoxide stream is passed through the line 18 through the precipitated solids taken and burned with additional air in the one overflow from the settling tank 4 via a drying device 7, so that the line 8 in a distillation plant 9. In this 15 for drying the wet solids in the dry context, it should be noted that the control device 7 required thermal energy is generated, that amount of the precipitated solids, the remaining part of the carbon monoxide is transported to the waste site, the residence time of the through the line 19 to the distillation plant 9 and the solid that is carried along by it, where it is reacted with additional air so that substances in the settling tank 4 are selected and ao thermal energy is produced for the distillation. The adjustment should be made so that the desired amount of combustion products is obtained from the front of the incineration precipitated solids together with the neutralization 7 and the distillation system 9 via the liquified water through the overflow into the line 8 lines 20 and 21 to the outside into the atmosphere , while a larger part of the escort,
can settle insoluble ash. As in the desulphurization plant 16, the slag is

In the distillation system 9 it can be a stream and then crushed with steam and air act any commercially available plant, brought into contact, so that the calcium and magnesia Most of the neutralized water siarasulP.d evaporated to calcium and magnesium hydroxide and is condensed so that those in it are converted and hydrogen sulfide and sulfur solubilized and solids entrained by the water in 30 dioxyd arise. The hydrogen sulfide and that In the form of a slurry or in dry form, sulfur dioxide is converted in such a way that lag behind. The distilled and thus purified that freer, elementary! Sulfur is produced by and treated water is withdrawn from the distillation line 22 and stored accordingly Plant 9 is withdrawn through a line 10 and can be.

35 The withdrawn from the desulphurisation plant through appropriate forwarding and distribution

neither for household nor industrial consumption - slag contains ash, calcium oxide, magnesium-

led or in a nearby stream oxide and other compounds. Part of this

or river can be derived. ^{Slag is Α} ~ τ through the conveyor device 23

In this context is also supplied to bemer waste disposal. The other part is using

ken that for the case in which no distilled water 40 of the conveying device 5 again for neutralization

but only neutralized water is to be produced, device 1 is returned and returned to de.i

the distillation system 9 initiated from the process drive away cycle.

can be left. In this case, the new The F i g. 2 shows a schematic individual view Tralized water is withdrawn through line 8 from the settling system 13 and the desulfurization tank 4 and directly from its further 45 system 16. The incineration tank 25 contains a Determination supplied- iron melt pool 26. The crushed sulfur-containing

The carbon fuel in the distillation plant 9 from the water is in the lower area of the separated solids are introduced from this distillation iron bath 26 via a line 27 at which system 9 deducted via a line 12 and one is a water-cooled pressure line or Drying device 7 supplied and can act there with the 50 a similar device. The ones from the insoluble ash and other solid drying device 7 coming dried solids mixed, which through the line 5 in the substances, the calcium and magnesium sulfate, over-drying device 7 can be initiated. In the case of calcium and magnesium oxide and others Drying device 7 can contain any compounds that arrive via line 14 commercially available rotating drum or other 55 into the combustion chamber 25 and form a ge drying device act in which the ashes melted a layer of paint on the surface and the other solid components are dried in the iron bath 26. Through the line or pressure. From the drying device 7, the line 29 passes a limited volume of air into the dried solids using any iron bath 26 introduced. In contact with the donor, Appropriate conveying device 14 into the 60 molten iron dissolves the carbon from the combustion plant 13. Fuel in the iron or is removed from it.

In the incineration plant 13, this is sorbed into the and thereby settles with the formation of carbon

calcium sulphate contained in dried solids turns into substance monoxide with that from the air

Calcium sulfide is reduced and that in the dried oxygen. In the same way, the

Calcium oxide and magnesium contained in solids are absorbed by iron, however

oxides are either wholly or partially converted to calcium - as a result of the higher chemical activity of the charcoal

sulftd and magnesium sulphide are converted by being prevented from coming into contact with the sulfur

to react with the oxygen originally in the carbonaceous oxygen.

monoxide gets out together with the nitrogen The slag withdrawn from the combustion air via the tapping line 30 up through the slag layer 28 and nung chamber 25 is flowed out of the boiler 25 via the line Xl this becomes coal and is crushed. This cooled and crushed; toffmonoxyd containing gas stream further with air 5 slag is then reacted in a contact device, so that carbon dioxide is produced and fed to 34, in which it moves downwards and thus generates thermal energy for the distillation and drying processes that went into intimate contact with steam and air is enough. The contact device 34 in turn contains the ash consisting of the incombustible components of the lettuce elements or other similar means, by which fuel rises in the iron bath 26 10 intimate contact with the slag on the one hand and upwards and is through the steam and air in the slag layer on the other caused. 28 located oxides slagged and melted. In the contact device 34, the steam is set. In addition, the slag layer 28 also serves as a desorbent for the formation of hydrogen sulfide in the iron bath 26 with the sulfides in the slag. The considerable sulfur, as the reactions contained in iron, can be represented as follows: Sulfur with the oxides in the slag under BiI- q ^ & _f- 2H O -> HSI <~ i (OH)
conversion of sulphides. These implementation rules - MeS + 2 h! O-> h! S + Me (OH),
gears can be represented as follows: ⁶ * " ^ev '*

2CaO + 2S-> 2CaS 4-2Γ01 Part of the hydrogen sulfide thus formed reacts

Tnx-r »1 ic iu" cj -> \ γ \ λ '° ^{m' 1} the ^au s under the air-derived oxygen

2MgO + 2S -> 2MgS + 2 [O] _{binding of sulfur dioxide and this χΜ itself}

The slag layer 28 is again with the additional hydrogen sulfide by tapping

Run 30 continuously from the combustion boiler with the formation of elemental sulfur vapor.

25 deducted. Thus, sulfur becomes in the form of These conversions can be represented as follows:

Calcium and magnesium sulfide continuously added as 3HS + 3/20 - * SO + 2HS + HO

together with the ashes and other compounds from 2H * S + SO - * 3 S + * 2H O * *

deducted from the combustion boiler 25. * * ²

The temperatures in the combustion boiler are. It should be noted that the aluminum is about between 1425 and i485 C. At this tempera oxide ur.d the other constituents in the slag as The iron bath remains in the molten state and the catalysts for the conversion between the that heat which is required to form both the hydrogen sulfide and the sulfur dioxide Iron hydroxide act in the elemental sulfur in the combustion chamber 25. However, it can Solids introduced from the drying device 7 may still be necessary, nor an additional catalyst also add the pyrite of the sulphurous carbon, depending on which fuel is used The acid mine water to be treated is converted into iron by the sedimentation the unwinding implementation processes. and from which components the resulting

It is thus composed of slag held in the combustion chamber 25,

molten iron is generated, which continuously flows over the The sulfur vapor flows in the contact

Line 31 is discharged. Following the line 34 upwards and finally arrives at the

device 31 can the molten iron in a granu- 40 line 37. The converted slag, which is in the

Iator 32 introduced, in this granulated, i. H. the lower part of the contact device 34 collects,

is reduced in size and finally taken to storage still contains unreacted calcium and magnesium

the. There are comminution devices in the trade siumoxide, calcium and magnesium hydroxide, ash

available, in which the molten iron to and other constituents. This used up slag

is cooled sufficiently to solidify, 45 is removed via a conveyor 38 from the contact

whereby it is crushed at the same time. Such a device 34 conveyed out. As above

known device can also be carried out in conjunction with a part of this slag

of the invention can be used. the NeutraUsationsvorrichtung 1 supplied while

The incinerator 13 is thus used to send the remaining slag to a waste disposal site

Purposes. First of all, it supplies the heat energy. The sulfur fumes get through the pipe

gie for the distillation and drying process of 37 in a condenser in which the vapors de;

process according to the invention, and secondly, elemental sulfur will be condensed. diesel

Sulfur is drawn out of the fuel, whereby condensed sulfur is then extracted via a <

Combustion products are obtained that do not have a line 39 in appropriate storage containers

Sulfur compounds contain more and those without 55 passed.

further to the outside into the atmospheric air. It should be noted here that for profit

can be left without the danger of sulfur from calcium sulfide already numerous

there is air pollution. Third, the method is known and that one of these is known

Combustion plant iron from the sulfur-containing process also in connection with the invention

term fuel contained pyrite and from the 60 according to the method can be applied.

Iron hydroxide obtained, which in the from the. Furthermore, it should also be noted that there

Drying device 7 introduced solids ent- method according to the invention also carried out

hold is; and fourthly, the can is extracted without the acidic mine water being mixed with ver

Sulfur in the form of sulphides, which is neutralized from the sulphates of the slag that is needed. so that means

are obtained, which originally in the acidic 65 that the acidic mine water directly into the De

Mine water were contained and which can be introduced from the dry stillalionsanlage 9 without dal

device 7 and also from the sulfur initially the neutralization system 1 and the Ab

hooked fuel come. set container 4 passes through. In this case, di

ic

In the distillation plant 9 separated from the water A stream of 466 200 kg / day of carbon monoxide solids via line 12 of the drying device and other gases from the incinerator 13 device 7 and then via line 14 of the combustion are via line 19 of a distillation plant 9 system 13 supplied. fed. This is an air flow of 646200kg / The sulfates contained in the solids are brought to reaction for 5 days in order to generate heat for the distillation in the incinerator 13 in the above-mentioned manner, reduced to sulfides. Then a flow of 11.13 kg / day of exhaust gas with a temperature of 138 ^C C, the now sulfide-containing solids is obtained, which is fed via the line to the desulfurization system 16, in which 21 is released into the atmosphere, the elemental sulfur in the The above-described solid-water slurry obtained by the same manner. Subsequently, the solids from the desulphurisation system, which have been skilfully consumed via the line 12 (65,700 kg / day of solids), arrive at the dryer 7, in which they are directed at 16 to the waste disposal facility. Since 6300 kg / day of solids are brought together, but in the course of the process according to the invention, which enter the dryer 7 via line 5, the slag stream is consumed, 15 46 800 kg / day of solids are found from the settling that a neutralization of the acidic Container 4 brought via line 6 to the heap of mine water with the spent slag from. 72,000 kg / day of dry solids economic point of view is justified because the Notwent ¹ are from the dryer 7 at a temperature thereby largely eliminated ness that of 1204'C 14 by means of the conveyor of the costly for the distillation corrosion ao incinerator 13 supplied, resistant building materials must be used. A stream of 81 900 kg / day of carbon monoxide to initiate the procedure of the invention and other gases having a temperature of 1199 ° C so that the melt has a sufficient will be introduced from the incinerator 13 through the Lei amount of iron into the combustion chamber 25, device 18 is supplied to the dryer 7. This forms an iron layer 26, and then enough air flow of 113,400 kg / day has to be burned in order to introduce the fresh lime so that the heat required in the dryer 7 can thereby be supplied. The ash contained in the burned fuel results in an exhaust gas flow of 286,200 kg / day with slag and then the slag obtained in this way to a temperature of 121 ° C., which is brought via the line neutralization device 1. As soon as 20 is discharged into the atmosphere, but this has happened once, with the prepared and cleaned acidic mine water containing 30 150 300 kg / day of crushed sulfur, coal, which has the following composition, sufficient amounts of calcium and magnesium, are over the line 27 is introduced into the combustion, so that a stream of slag rich in calcium oxide and magnetization container 25 is obtained

easily reintroduced into the process cycle

leads can be. Free carbon 62.3

In the following, with particular reference to Free Sulfur 2.0

on Fig. 1 a quantitatively occupied execution oxygen (as carbon monoxide) ... 10.5

example described. Iron pyrite $ 3

A stream of 7519 kg per day of sour mines - 40 hydrogen 4J2

water with a temperature of 21 ⁰ C and the following nitrogen I ₁ O

Composition is via line 2 of the new aluminum oxide 6.6

centralization device 1 supplied. Silicon dioxide (,] (,

ppm water 3 ^ 0

Acidity 1000 ⁴⁵ Total: 100.0%.

Sulphate content 3800

Total Iron 300 ^. ,. _.

Kalziumgehait 370 After the beginning of the combustion vessel 25

Aluminum content 60 ^'n 120 ^{50 Kalkste with CMER} sufficient amount of flux to dolomite magnesium content "of 60 weight percent calcium carbonate

and contains 40 weight percent magnesium carbonate

Be a day 30,000 kg of was charged into the circulation and iron, Tempe Back Guided slag was introduced at a temperature of temperature for the combustion reaction to 1480 ⁰ C overall 21 ° C above the conveyor 3 of neutrality. A flow of 441,900 kg / day is fed to incinerator 1. In addition, air at a temperature of 777 ° C. is blown in in a total flow of 7575 kg / day of neutralized combustion container 25 via line 29, water and solids from the neutralization system. A total flow of coal direction 1 is fed to the settling tank 4. 53100 kg / monoxide and other gases in an amount of day solids are separated from the neutralized water 582 300 kg / day at a temperature of 148O ⁰ C in the sedimentation tank 4 and 7522 kg / Tpg 60 testifies to the line 17 from the Container 25 meutfiwsierter water with a temperature of 21 ⁰ C is discharged. 72,400 kg of slag are fed daily via line 8 to the distillation plant 9 from the incineration tank 25 via the tap. 7407 kg / day of potable distilled water ri & ss 30 withdrawn at a temperature of 1480 ° C, are withdrawn from the distillation plant 9 at a temperature of 65 ° C via line 10 after cooling and comminution. 65 from the combustion container 25 into the contact 65 700 kg / day solids, which is transferred to an aqueous system 34, where they only 9000 kg / day steam slurry with a temperature of 65 "C fee and a sufficient amount of air together ., are withdrawn via line 12. Is brought to steam from elemental sulfur

in an amount of 16,200 kg / day at a temperature of 150 ⁰ C to generate. The sulfur vapor and the other gases are drawn off from the contact system 34 into the line 37, condensed and stored. In the contact system 34 arises daily

an amount of 69,300 kg of used slag which is withdrawn via line 38. 29 700 kj the used slag are returned to the neutralization device 1 in the circuit zi unc 39,600 kg / day are discarded.

1 sheet of drawings

Claims (3)

other atmospheric moisture conditions Patent claims: decompose again or disintegrate again, so that again it comes to a water pollution. 1. Process for the recovery of sulfur from The present invention is intended to provide a process Acid mine water containing sulphate ions, 5 for cleaning and processing of acid mines thereby characterized that from the wä-wern are created, on the one hand drinking water the water dissolved in it and taken with it and, on the other hand, other useful secondary solids separated and dried so that products are obtained that can be put back on the market the dry solids can then be brought to the reduction, so that through this Sulphates contained in them turn into sulphides in an io eritite proceeds the operating costs for the process carbon-containing iron melt pool introduced either partially or even completely covered, be that then contain the sulfides- This object is solved wildly according to the invention, The solids are removed from the molten iron bath and those dissolved in the water are drawn along with it and finally these sulfides are separated into per se solids and dried can be converted into elemental sulfur in a known manner, so that the dry solids are then converted to re-conversion will. reduction of the sulphites contained in them to sulphides 2. Reverence according to claim 1, characterized thereby introduced into a carbonaceous iron melt bath draws that oxygen and a sulfur are contained, that then those containing the sulfides The carbonaceous fuel is drawn into the iron solids from the iron melt bath and Molten bath are introduced. 20 finally these sulfides in a manner known per se in 3. Process by one or both of the pre-elemental sulfur are converted, going claims, dadui.h characterized in that a particular advantage of the Verdie according to the invention oxide-containing snags that drive after removal consists in its implementation of the sulfur from the sulphides containing, from a coal with a high sulfur content as fuel Solids withdrawn from the molten iron bath may not normally be used as remains, is useful for neutralizing the acidic fuel, since the combustion pro-mine water is used, and the resulting coal would otherwise have a corresponding air retention S ^ ilacke with or without those in others cause contamination. Manner withdrawn from the safe mine water. In the case of the method according to the invention, Solids dried and in the iron melt 30 proceeded moderately so that oxygen and a sulfur bad is introduced. fei containing carbonaceous fuel into the Eiscn melting bath can be introduced, the Carbon is oxidized to carbon monoxide and c> r