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The influence of cyanide salts and ferrous sulphate on pyrite flotation

Kostovic M., Vucinic D.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

609--619

EN

The effect of cyanide salts as depressants, i.e. sodium cyanide (NaCN) and complex cyanide salts such as potassium ferricyanide (K3Fe(CN)6) and potassium ferrocyanide (K4Fe(CN)6), as well as combination of sodium cyanide with ferrous sulphate (FeSO4/NaCN) on pyrite flotation was investigated. Tests covered the frothless flotation of pyrite under different concentrations of depressants at various solution pH’s with potassium butyl xanthate (KBX) as collector. Flotation test results have shown that NaCN, and even more the combination of reagents FeSO4/NaCN are more successful in pyrite depression than complex cyanide salts, such as K3Fe(CN)6 and K4Fe(CN)6. Surface characteristics of pyrite were studied using rest potential (Eh) measurements and infrared attenuated total reflection spectroscopy (ATR-IR). In the presence of tested reagents in the flotation system, iron cyanide compounds and hydrated iron oxides were formed on pyrite surface. The composition of formed compounds depends not only on cyanide ions in the solution, but also on the pH of the system and solution species. These compounds, depending on the reagents used, are responsible for the resulting efficiency of the pyrite depression.

2

Decomposition of pollutants in textile wastewater during the Fenton process in the presence of iron nanocompounds

Kos L., Sójka-Ledakowicz J., Michalska K., Perkowski J.

Environment Protection Engineering

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2016

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Vol. 42, nr 3

71--83

EN

The efficiency of the decomposition of pollutants in textile wastewater has been determined by the Fenton method in the presence of iron nanocompounds and the results have been compared with those by the classical Fenton method. The wastewater was purified with ferrous sulfate and ferrous sulfate with the addition of iron(II, III) nanocompound. The effect of optimization of the process was examined by adding various amounts of ferrous sulfate and iron(II, III) nano-oxide, hydrogen peroxide and changing pH of the solution. It was found that addition of iron nano-oxide in the presence of ferrous sulfate increased the efficiency of pollutant decomposition in the wastewater.

3

Oczyszczanie wód metodami chemicznymi : czy zawsze konieczne?

Kowalski T.

Inżynieria i Ochrona Środowiska

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1998

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T. 1, nr 1

25-38

PL

Wykazano, że stosowane do oczyszczania wody koagulanty różnią się właściwościami chemicznymi. Produkty dysocjacji i hydroanalizy siarczanu glinu tworzą głównie trudno rozpuszczalne sole, podczas gdy produkty reakcji koagulantów żelazowych tworzą ponadto rozpuszczalne barwne kompleksy. Stwierdzono, że siarczan glinu jest bardziej uniwersalnym koagulantem, pozwalającym uzyskać dość stabilne wyniki oczyszczania niezależnie od rodzaju oczyszczanych wód. W przypadku użycia koagulantu żelazawego można oczekiwać mniej stabilnych rezultatów oczyszczania i zaleca się stosowanie dodatkowo filtracji przez złoża uformowane z częściowo zdekarbonizowanego dolomitu.

EN

Surface waters usually need coagulation treatment before supply to a municipal system. Although the physicochemical phenomena concomitant with aluminium or iron - salt coagulation are similar, the products from the dissociation or hydrolysis of the two coagulants follow different behavioral patterns. Thus, those of alum are prone to form (predominantly) low - solubility salts with the iron - humus complexes present in the water. These reactions are slightly delayed due to the reactions concomitant with complexing, i.e. calcium - to a magnesium or magnesium - to - calcium conversion (according to the water parameters). And this enhances the reaction of the coagulant with other pollutants, which manifests in a slight decrease (by 20% O in the efficiency of organic matter removal. The products from the dissociation and hydrolysis of the iron - salt coagulant are prone to form partly solube iron - humus complexes. These reactions are also combined with calcium - to - magnesium or magnesium - to - calcium conversion, but the deterioration of organic matter removal is considerable (by 40%). Based on these findings the following generalizations can be made: When the water to be treated carries a variety of polluting species, aluminium coagulant is preferable, because iron salts may produce considerable variations in the efficiency of organic matter removal (60 to 90%). When humic substances are the dominant polluting species, it does not matter whether aluminium or iron salt is used as coagulant.