CC BY
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AZ9RBAYCAN KIMYA JURNALI № 4 2017
UDC 669.334.6
PURIFICATION OF SULPHATE CONTAINED TECHNOLOGICAL SOLUTIONS FROM ARSENIC BY HYDROLYTIC PRECIPITATION AND RECEIVING OF SELECTIVE Cu, Zn, Co, Mn CONCENTRATES
A.A.Haydarov, A.A.Guliyeva, A.B.Muradova, A.X.Qurbanzade
arif.heyderov.54@mail.ru Received 26.12.2016 M.Nagiyev Institute of Catalysis and Inorganic Chemistry, NAS of Azerbaijan
In the article information is given about tailings which were received from enriching of iron ore irrigated by heap leaching method purification of As by hydrolytic precipitation and receiving selective Cu, Zn, Co, Mn concentrates. As a research materials were used tailings from "Dashkesan Ore Purification" factory and solutions which were received after irrigation of processing of North Dashkesan Co deposit. In percolation columns content of solutions received after irrigation are as follows (I sample at pH=2): Al - 3.23, Fe -13.63, Mn - 1.89, Cu - 0.64, Co - 5.8, Zn - 89.16; (II sample, pH=4.8); Ca - 223, Mn - 13.83, Co - 478, Cu - 10.2, Zn - 4.34. Precipitation of valuable components by hydrolytic method from received solutions by increasing pH from 1 to 11 provided stage by stage and as a result were received 3 type concentrates.
Keywords: tailings, solution, percolator, precipitation, metals.
Introduction
Currently in Azerbaijan on the territory of Dashkesan mining enterprises there has been collected a large amount of industrial waste polluting an environment. This tailing are potential raw material obtaining some valuable metals.
Utilization of this tailings is an actual problem and will solve two problems. Firstly it will improve ecological conditions and secondly it will be possible to get valuable metals such as Cu, Zn, Co, Mn, Al, Mg and so on. As can be seen that processing of tailings and production of valuable metals have economic interest and will prevent migration of metals to environment.
Producing concentrates by the wet and dry method of purification company after magnetic seperation of all sulphate and sulphoarsenates, also non-ore minerals of Cobalt pollutes valley of Goshgar river. The calculations based on approximate volume, special weight and other parameters of wet tailings in sand showed that it was around 20 milion tons. As the samples were taken from different areas concentration of metals in the samples are different. According to granulometric compound 70-90% of tailings consist 0.3 mm size particle which is favorable factor for dilution. In work [1] while irrigation of tailing acid used in heap leaching and concentration of extracted metals were determined according to taken samples.
The main aim in this work is extracting Cu, Zn, Co, Mn, Al from waste which were taken from Dashkesan ore basin by hydrolytic precipitation and cleaning from As.
For extracting Al, Co, Cu, Zn, Mg sulphates by utilizing from As the various methods such as sedimentation, extraction, sorption and precipitate hydroxides by hydrolytic method [24] are known.
Analysis of scientific patent data showed that for extracting metals from multicomponent sulphate solutions and receiving precipitations with hydroxides may be possible by hydrolysis of solutions.
Materials and methods
As a research object were taken wet enriched tailing samples from "Dashkesan Ore Purification" plant. Initial chemical analysis of different samples taken from "Beach" waste area were carried out with "Bruker S2 Pikofox" X-ray fluorescence spectrometer. Analysis showed that in tailings Co, Cu, Mn, Al have high concentration, Zn, Pb, Ir, Sr, As have low concentration. Analysis provided in differend areas showed that concentration of the components in tailing are differend.
Testing iron ore tailings by heap leaching method in laboratory conditions has been done in percolation columns with 25 cm height and 3-4 cm
diameter. Tailings with known weight (0.3-0.5 kg) was filled in columns and was irrigated with 1N H2SO4 by drop method. Chemical compound of solutions after irrigation were complicated and differed by their pH. In work [1] was determined that after 6 time irrigation with 1N sulfuric acid 65.9% Co, 30.5% Cu, 25.1% Zn, 17.5% Mn, 4% Fe and 1.82% Al convey to solution. Utilization As from sulphate solution and precipitation of precious metals as hydrate form was done at 400C temperature in laboratory mixer at electric heater in glass plates with n=600-1 rotation frequency. Duration of hydrolytic precipitation was 0.5 hour and solution with precipitation was filtered after 24 hours. pH increased to 11 stage by stage with lime and NaOH solutions and decreased with limpid sulfuric acid. pH measurement was done with portable pH/EC/IDS/IJ 9813-6 device.
Results and discussion
For the first time standart practices have been carried out with sulphate solutions of Cu(II), Zn(II), Fe(II), Fe(III), Mn(II), Co(II) and the results were tested in technological solutions. In literature it has been showed that as a result of neutralization pH sulphate solution of non-ferrous metals it is possible to obtain not only metal hydroxides but also basic salts. However, there is no more information about
precipitation of metals as hydroxides from technological solutions with low concentration at probably room temoerature (20-300C) and treatment from arsenic. Compound of hydrated precipitation was determined in limpid solutions at room temperature (concentration of metals 0.05-1 g/l) with 0.1N NaOH solution during 60 min by potentiometric titration. In Figure 1 there a given the results of potentiometric titration of Co, Cu, Zn, Fe, Al and Mn sulphate salts with 1N NaOH.
As it can be seen from the character of curves after titration of II and III valent sulphate salt solutions different compositions of sediments were formed. Initial precipitation in 0.01 M solution for Zn is at pH=6.4, complete precipitation at pH=8; for copper initial precipitation is at pH=6.3, complete pred for Fe(III) initial precipitation is at pH=2.5, complete precipitation is at pH=4.57.
By IR spectroscopy and chemical analysis proved once again that when sulphate concentration of metals in solution is from 0.01 to 100g/l there forms MeSO4-3Me(OH)„ containing basic salts, but if solution is saturated, from them forms Me(OH)n contained simple hydroxide precipitations (Me=Cu2+, Zn2+, Co2+).
pH
0
6
1
r
r ■ II 1 1 1
4 1 1
0
1
2 3 4 5
OH7Mc"
Fig. 1. Dependence pH value salt solutions of II and III valent metals after potentiometric titration with 1 N NaOH from OH"/Me"+ ratio: 1 - Cu, 2 - Co, 3 - Zn, 4 - Fe, 5 - Al, 6 - Mn.
Based on chemical composition and concentration of metals in solution as a simple and cheapest variant for the processing we offered precipitate Fe and As with lime as tailing, non-ferrous metals selective hydrated sediments. Because of the high toxicity concentration of arsenic must not exceed 0.05 mg/l. The most famous method of recovery of As from technolofgical solutions is the precipitation of As as Fe(III) scorodite (FeAsO4 H2O) at pH=2. pH of technological acidic solutions will decrease with lime solution to 2-3, it can be possible to reduce concentration of as in solution to 0.02 mg/l. If precipitation takes place at room temperature low green amorphous FeAsO4H2O will be achieved [5]. If experiments are done upper than 900C there will be achieved low soluble crystallic FeAsO4H2O sedimentation [6, 7].
Firstly, as concentration of Fe is 7.5-13.6 g/l and As is 0.1-2.234 g/l, it allows to
3+
precipitate As as scorodite without adding Fe to solution, and also to precipitate sulphate ions as gyps (CaSO4). If sulphate contained solutions neutralize Fe2+ and As3+ ions after oxidizing with appropriate reagents (air, H2O2, KMnO4, etc.) forms amorphous and crystallic precipitations is proved by IR spectroscopy or X-Ray analysis.
Chemical reactions during neutralization
as follows:
CaC03+H2S04^CaS04 2H20+C02, 2FeS04+H202+H2S04^Fe2(S04)3+2H20, Fe2(S04)3+3Ca(0H)2^2Fe(0H)3+3CaS04, H3As03+ H202^H3As04+H20, 2H3As04+ Fe2(S04)3->2FeAs04l+3H2S04, Fe(OH)3+ H3As04-> FeAs04 2H20+ H20, Fe2(S04)3+2H3As04^2FeAs04l+3H2S04, Fe2(S04)3+2H20-»2Fe0HS04+ H2S04, 2H3As04+3CaC03-»Ca3(As04)2l+3C02+3H20.
Precipitation experiments of arsenic and iron from technological solutions were given in Table 1. As it can be seen at pH=3.2 As and Fe were precipitated, Zn2+, Cu2+, Co2+, Mn2+, Mg2+ ions stayed in solution.
Table 1. Results of precipitation of Fe and As from solution
Expenditure of CaCO3, g/l pH Concentration of components in solution, g/l
H2SO4 Fe Cu Zn Co As Al
0 1.0 31.2 13.63 0.64 0.089 0.007 0.23 1.9
30 2 24.5 3.54 0.64 0.089 0.007 0.05 1.9
45 2.8 8.2 1.45 0.64 0.089 0.007 0.02 1.9
60 3.2 4.1 0.1 0.63 0.086 0.007 0.01 1.8
In Table 2 were given chemical compound after neutralization when expenditure of lime is 45 g/l.
Table 2. Chemical compound of composition after neutralization at pH=2.8_
Components CaO Fe S Cu Zn Co As
Mass portion, % 31.2 35.5 30.1 0.09 0.004 0.003 0.086
As it can be seen from Table 1, when pH range is 2.0-3.2 precipitation of As and Fe is optimum. In the given range precipitation of Cu, Zn, Co, Al does not exceed 3.5 %.
After irrigation of the same tailing by 3 stage with 1N sulfuric acid the acidity of the solution changes between pH=1-4 range. If this solutions will be mixed without adding lime, acidity of solution increases to 2.5 which involves
• • • 2 | O j Ç j O j
precipitation of Ca , Al , As and Fe from
solution, but Ca precipitates absolutely (Table 3).
Table 3. Mass portion of metals at pH=2.5 in hydrated precipitations_
Sample Al S Fe As Ca
No 1 4.63 7.03 8.61 1.12 0.28
No 2 2.81 4.85 31.38 4.66 0.046
After extraction of precipitations in Table 3
3+ 5+
increasing pH of solution to 4 by NaoH Al , As and Fe3+ will precipitate absolutely (Table 4).
Table 4. Mass portion of metals at pH=4 in hydrated precipitations_
Sample Al S Fe As Ca
No 1 5.91 7.56 6.12 0.6 -
No 2 4.33 6.99 25.13 0.24 -
The results in Table 3 confirm that there significant Fe, Al, As and Ca in iron-gypsym precipitation. If price of pH will be upper than 4.5 it leads to 10% precipitation of Cu, Zn and Co to hydroxide contained precipitation. As it is not possible to receive complete of precipitation Fe, Al and As from solution at pH=3, it is not desirable. At pH=4 X-Ray analysis of hydrated precipitation (Table 4, sample No 2) shows that the sample is amorphous.
Fig. 2. IR spectra of sediments precipitated from Fe(III) sulphate and technological solutions.
For the identification of this sediment there was used IR spectroscopy. In Figure 2 were given IR spectra of hydrolysis products of pure Fe2(SO4)3 and the precipitation sample No 2 and pH=4. Both sediments spectra are close to each other. In 3000-3600 cm-1 absorption range of IR spectra of received amorphous samples mathes wide absorption range with 3377.25 and 3362.49 cm-1 maxima. It is suitable for valent dances of OH- group of molecular water. Deformation dances of water molecula seems like strip at 1633.66 and 1644.44 cm-1 spectra. As in valent dances area of OH-1 (3000-3600 cm-) it can not be seen narrow absorbtion strip shows that there is no hydroxyl OH-1 groups. In IR spectra of second sample can be seen 2 intensive strips (610.42 and 1111.83 cm-1) which show that there
is SO
group. The diffuse for valent dance of
H2O and SO2 shows disorderliness structure of this compound. It is assumed that chemical compound precipitated from solution is amorphous base sulphate of iron: Fe2O32SO3xH2O. The presence of this compound is approved by work [8].
Concentration of As in cake changes between 0.24-4.66% and it makes hard to precipitate with iron in small disperse phase.
In next stages of processing investigations were provided for receiving marketable copper-zinc concentrates.
If pH of the solution received after second stage is increased to 6 by CaCO3 at 400C there will be precipitated copper, zinc and cobalt. The results of experiments are presented in Table 5.
-i
v. cm
Table 5. Chemical compound of neutralization product
pH Amount of elements in solution, g/l
Mass of sediments, g Mg Al Co Cu Zn Mn As Ca Fe
2 0.364 0.778 0.007 0.117 0.047 0.357 0.0003 0.075 2.187
Amount of elements in cake, %
2.5 0.373 4.63 0.035 0.0028 0.0011 0.032
4 0.549 5.91 0.072 1.6 0.0017 0.034
5.5 1.939 1.53 4.83 0.0635 1.060 0.14 0.49 0.0008 0.0103 0.253
9 0.563 8.76 0.24 0.017 0.026 9.53 0.0016 0.091
10 0.232 6.78 0.05 0.37 0.0035 0.00188 0.0002
11 0.150 6.08
Precipitation, % 97 99.55 99 97 95 96 96.5
lysis of sample showed that the sediment is amorphous. For explaining the chemistry of sediment were used IR spectra. In IR spectra of sample at (Figure 3) 3200-3500 cm-1 and 1631.5 (1639.9) cm-1 frequency observed absorption strips match OH- group dance in moleculer water.
In IR spectra of OH- group valent dances area can be seen narrow absorption strip (3631 and 3696.90 cm-1) which indicates hydroxide group. 524.88 and 464.23 cm-1 absorption band indicates Co-O band [9]. In sediments received
from technological solution can be seen strips
2 1 belonging to SO group. (500-700 cm- and
1000-1200 cm-1). Analysis showed that there
are SO 4~ groups in sample.
Table 6. Precipitation of non-ferrous metals from irrigation of Co enriched ores with 1N sulfuruc acid
Amount of elements in solution g/l
pH Mass of sediment,gr Ca Mn Fe Co Cu Zn As S
4.18 223 13.83 - 478 10.21 4.34 234.4
Amount of elements in cake, %
6 1.095 7.63 0.43 0.307 12.37 0.438 0.11 10.04 10.02
8.5 0.67 0.162 0.296 2.10 0.124 0.27 5.46
11 0.417 7.29 0.78 0.075 17.78 0.11 1.28
Precipitation, % 99.66 99.5 99.0
J so
4D
30 20 10 o -10 60 SO AO 30 20 io o
-ID
■looô 3SOO 3000 2500 2000 1SOO 10OO 500
v, cm-1
Fig. 4. IR spectra of sediments precipitated from Co(III) sulphate and technological solutions.
Precipitation contains from 1.06%, 1.6% Zn. As can be seen from the table in cake precipitates 98.5% of Cu, 98% of Zn and 80% of Co. The preence of iron in the sample is caused by precipitation of Fe2+.
Comparing mass portion of Fe, Cu, Zn and Co in sediments showed that for receiving Cu and Zn enriched sediments from technological acidic solution pH of solution is not to be raised more than 6-7. Increasing pH to 9 leads to increasing amount of Co and Mn in sediment.
In Table 6 the results of irrigation of Cobalt enriched ore by 1N sulfuruc acid by hydrolytic precipitation are offered.
As it can be seen at ph=11 99% of Co, Cu, and Zn precipitates from solution X-ray ana-
As it can be sen that co precipitates from solutions as amorphous basic salt. Mass portion of Co in precipitation reaches to 17.78%. It can be seen from Table 5 that reaching pH to 9 with limestone leads to precipitate Mg and Mn absolutely after extracting Co (Table 5). Concentrate consists of 8.76% Mg and 9.53% Mn.
Lastly offereds is the technological scheme of utilizing Fe-As from irrigated solutions by heap leaching and changing pH with hydrolytic method and receiving selective concentrates such as Cu, Zn, Co, Mg, Mn and etc. (Figure 4).
H2SÜ4(limpid)
pH=1 __
Tailings, S olution
\t
Solution
CaCÜ3
pH=2,5
I
Fe,As,Ca,Al prec ipitation
Filter
CaCÜ3 pH=6 1
Co,Cu Precip ,Zn,Fe itation
Fi lter
CaCÜ3
pH=8.5
CaCÜ3
pH=11
I
Precipitation Co
v
Fil ter
\ t
I
Mg,Mn, precipitation
L *
failing
Filter
i
As contained garbage
Co,Cu,Zn precipitation
Co
concentrate
Mg,Mn precipitation
Fig. 4. Precipitation of As and metals as selective concentrates from irrigation solution of tailings.
References
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2. Панов Д.С., Суднев А.Г., Скороходов В.И. Сорбционное разделение кобальта, марганца, никеля и меди в производственных растворах // Металлургия. 2012. № 3. С. 85-86.
3. Медяник Н.Л. Изучение закономерностей раздельного выделения основных компонентов сточных вод горных предприятий гидрометаллургического комплекса // Горный информационно-аналитический бюллетень. 2011. № 4. С. 295-300.
4. Жунусова Г.Ж., Алтайбаев Б.Т., Кальянова О.А., Серкебаева С.К., Садыканов М.М. Гидролитическая очистка сульфатных растворов от примесей железа, мыщьяка, сурьмы, алюминия и
кремния // Приоритетные научные направления: от теории к практике. 2013. № 8. С. 123-129.
5. Fisher K.G. Cobalt processing developments. The Southern African Institute of Mining and Metallurgy // 6th Southerm African Base Metals Conference. Mexico 2011. P. 237-256.
6. Robins R.G. The stability and Solubility of Ferric Arsenate. An Update. In: EPD Congress 1990. Gaskell D.R. (Editor). TMS, Warrendale, PA. P. 93-104.
7. David J. Droppert. The ambient Pressure Precipitation of Crystalline Scorodite (FeAsO4-2H2O) from sulfate solutions. Department of Mining and Metallurgical Engineering. McGill University. Montreal, Canada, July, 1996. 90 р.
8. Маргулис Е.В., Савченко Л.А. Исследование аморфного основного сульфата Fe2O3-SO3-wH2O // Журнал неорган. химии. 1975. T. 20. № 7. C. 1872-1875.
9. Накамото К. Инфракрасные спектры неорганических соединений М.: Мир, 1996. 412 с.
SULFATLI TEXNOLOJi MOHLULLARDAN HiDROLiTiK CÖKMO YOLU iLO ARSENDON TOMiZLONMOSi VO SELEKTiV Cu, Zn, Co, Mn KONSENTRATLARININ ALINMASI
A.O.Heydarov, A.A.Quliyeva, A.B.Muradova, A.X.Qurbanzada
Damir filizinin zanginla§masindan alinan tullantilann topa hallolma üsulu ila yuyulmu§ mahlullarindan hidrolitik Qökma yolu ila arsenin tamizlanmasi va selektiv Cu, Zn, Co, Mn konsentratlann alinmasi haqqinda malumat verilir. Tadqiqat materiali kimi "Da§kasan Filizsaflaijdirma" ASC-nin safla§dirma fabrikinin tullantixanasindan va §imali Da§kasainin kobalt yatagin istismanndan sonraki tullantilann yuyulmasindan alinan mahlullardan istifada edilmi§dir. Perkolyasion kalonkalarda (sütunlarda) yumadan alinmi§ mahlullann qatiligi a§agidaki kimi olmu§dur: (I nümuna pH=2) Al - 3.23, Fe - 13.63l, Mn - 1.89, Cu - 0.64, Co - 5.8, Zn - 89.16, (II nümuna pH=4.8) Ca - 223, Mn - 13.83, Co - 478, Cu - 10.21, Zn - 4.34 mq/l. Alinmi§ mahlullardan qiymatli komponentlarin Qökdürülmasi hidrolitik yolla pH=1-dan 11-dak qaldirmaqla pillali marhalalarla apanlmi§ naticada 3 növ konsentrat alinmi§dir.
Agar sözlar: tullanti, тэЫи1, perkolyator, gökm3, metallar.
ПОЛУЧЕНИЕ СЕЛЕКТИВНЫХ КОНЦЕНТРАТОВ Cu, Zn, Co, Mn И ОЧИСТКА ИХ ОТ МЫШЬЯКА ГИДРОЛИТИЧЕСКИМ ОСАЖДЕНИЕМ ИЗ СУЛЬФАТНЫХ ТЕХНОЛОГИЧЕСКИХ РАСТВОРОВ
А.А.Гейдаров, А.А.Гулиева, А.Б.Мурадова, А.Х.Курбанзаде
Представлены сведения о полученных селективных концентратах Cu, Zn, Со, Mn и очистка их от мышьяка гидролитическим осаждением из растворов, полученных кучным выщелачиванием из обогащенных железных руд. Объектом исследований являлись растворы, полученные из отходов ОАО "Горно-обогатительная фабрика Дашкесана" и отвалов переработки кобальтовых месторождений северного Дашкесана. Растворы, образованные после выщелачивания в перколяционных колонках, имели следующий состав: (образец I с рН=2) Al - 3.23, Fe -13.63, Mn - 1.89, Cu - 0.64, Co - 5.8, Zn - 89.16, (образец II с рН=4.8) Ca - 223, Mn - 13.83, Co - 478, Cu - 10.21, Zn-4.34 мг/л. Осаждение ценных компонентов проводилось стадийно гидролитическим путем при изменении рН от 1 до 11, и были получены три вида концентратов.
Ключевые слова: отходы, раствор, перколятор, осаждение, металлы.
