Wyniki wyszukiwania - BazTech

1

Utilization of solutions obtained after magnesium removal from sphalerite concentrates with spent electrolyte derived from winning of cathode zinc

Jarosiński A., Kozak A., Żelazny S.

Gospodarka Surowcami Mineralnymi

|

2013

|

T. 29, z. 4

107--118

PL

Krajowe złoża rud cynku i ołowiu występują w skałach dolomitowych co powoduje, że pozyskiwane koncentraty sfalerytowe zawierają domieszki dolomitu. Koncentraty te powinny cechować się wysoką zawartością cynku i niskim poziomem zanieczyszczeń, takich jak magnez, arsen, żelazo i inne. Krajowy proces wytwarzania cynku katodowego z powyższego surowca obejmuje: prażenie koncentratu sfalerytowego (w celu otrzymania cynku w postaci tlenkowej), ługowanie tego koncentratu kwasem siarkowym, oczyszczanie otrzymanego roztworu siarczanu (VI) cynku i elektroosadzanie cynku jako ostatni etap procesu. Podczas obróbki chemicznej koncentratu tlenkowego kwasem siarkowym magnez przechodzi prawie całkowicie do roztworu siarczanu (VI) cynku. Wysokie stężenie magnezu w tym roztworze jest niepożądane i przyczynia się do pogorszenia jakości cynku katodowego, jak również do pogorszenia wskaźników techniczno-ekonomicznych procesu elektrolizy. Postulowana zawartość magnezu w roztworze wynosi poniżej 0,3% MgO i dlatego MgO powinno być usuwane przed elektrolizą cynku. Jedną z metod usuwania magnezu jest obniżenie jego zawartości w koncentracie sfalerytowym na drodze ługowania wstępnego, stosując kwas siarkowy jako czynnik ługujący. Celem tych badań był odzysk niektórych składników z roztworów po usunięciu magnezu z koncentratu sfalerytowego poprzez jego ługowanie. Czynnikiem ługującym był zużyty elektrolit pochodzący z procesu elektroosadzania cynku. Badania obejmowały dwie zasadnicze serie pomiarowe: ługowanie wyjściowego koncentratu sfalerytowego zużytym elektrolitem z elektrolizy cynku i odzysk niektórych składników z otrzymanych roztworów. [...]

EN

As domestic zinc and lead deposits occur in dolomite rocks, the sphalerite concentrates obtained from these ores contain an admixture of dolomite. These concentrates should be characterized by a high content of zinc and low levels of impurities such as magnesium, arsenic, iron, and others. The domestic process of cathode zinc winning from this raw material consists of roasting of sphalerite concentrates (in order to obtain zinc in the oxide form), leaching of the oxide concentrate with sulfuric acid, purification of the zinc sulfate obtained, and a final stage – zinc electrodeposition. During chemical treatment of the oxide concentrate with sulfuric acid, magnesium is added to the solution of zinc sulfate. A high magnesium concentration in the solution is undesirable, and causes deterioration of zinc cathode quality, and technical as well as economical indexes of the process. The required content of magnesium in a solution amounts to less than 0.3%MgO; therefore, MgO should be removed before the electrodeposition of zinc. One of the methods of magnesium removal is decreasing its content in a sphalerite concentrate by means of pre-leaching, using sulfuric acid as a leaching agent. The aim of this study was the recovery of certain components from solutions after magnesium removal with zinc concentrates by means of pre-leaching. Spent electrolyte deriving from the zinc electrodeposition process was used as the pre-leaching agent. The study consisted of two major measuring series, namely leaching of raw sphalerite concentrate with spent electrolyte and removal of components from the solutions after pre-leaching. Leaching was carried out in three stages. After the first stage of the two-hour leaching, the extent of magnesium leaching was almost 84%. After the second and third stages of the leaching steps, magnesium content was slightly lower respectively 81.5 and 70.4%. Magnesium content in the concentrate was below the maximum permissible value, i.e. 0.30%. After the third stage, the content of this component was 0.40%. Zinc losses were highest after the first leaching stage at 2.6%, and were acceptable from a technological point of view. The results confirmed that the pre-leaching process with spent electrolyte is an effective method for the removal of magnesium and other impurities from zinc concentrate. The described procedure for purification and separation of components from a solution is an effective method of recovering some components. The resulting products can be utilized in various technological processes; for example, for the production of magnesium compounds, recycling of zinc product, winning of zinc, etc.

2

Removal of magnesium from sphalerite concentrates by means of spent electrolyte deriving from the process of cathode zinc extraction

Jarosiński A., Kozak A., Żelazny S., Radomski P.

Gospodarka Surowcami Mineralnymi

|

2012

|

T. 28, z. 3

43-53

EN

Due to the occurrence of zinc and lead ore deposits in dolomite rocks, the sphalerite concentrates obtained from these ores contain an admixture of dolomite. In practice, a substantial amount of magnesium included in zinc ores passes to the last production stage, i.e. zinc electrolysis. The magnesium present in electrolyte impairs electrical conductance and appears in the technical and economical indexes. This paper deals the attempts to remove magnesium removal from initial sphalerite concentrates by means of chemical flotation using spent electrolyte derived from zinc electrolysis. The authors attempt to substantiate the existing relationships, as well as to derermine the optimum conditions for the procedure suggested. The leaching efficiency of magnesium amounted to about 80%, and is dependent upon the stage of the leaching. Losses of zinc were below 2%, and the magnesium concentration in solution amounted to about 20%. These solution can produce magnesium and zinc, which will be presented in the following paper.

PL

Występowanie złóż rud cynku i ołowiu w skałach dolomitowych sprawia, że otrzymane koncentraty sfalerytowe zawierają domieszkę dolomitu. Praktyka wskazuje, że znaczna część wprowadzanego magnezu z surowcami cynkowymi przechodzi do ostatniej fazy produkcji, elektrolizy cynku. Obecność magnezu w elektrolicie obniża przewodnictwo elektryczne elektrolitu i powoduje pogorszenie wskaźników techniczno-ekonomicznych. Celem opisanych w tym artykule badań było opracowanie metody usuwania magnezu z surowego koncentratu sfalerytowego na drodze chemiczno-flotacyjnej, stosując zużyty elektrolit pochodzący z elektrolizy cynku. Opracowanie ukierunkowano wokół doświadczalnego zobrazowania istniejących zależności i ustalenia optymalnych warunków zaproponowanej procedury. Stopień wyługowania magnezu wynosił około 80%. Straty cynku wynosiły poniżej 2%, natomiast stężenie magnezu w roztworze wynosiło 20%. Z tych roztworów można odzyskiwać magnez i cynk, co będzie przedstawione w następnej publikacji.

3

The optimization of low-magnesium zinc concentrate production process

Jarosiński A., Fela K.

Polish Journal of Chemical Technology

|

2009

|

Vol. 11, nr 1

20-23

EN

In this paper the result of the study on chemical leaching of zinc concentrate with H2SO4 solution was presented. The object of this work was to assess the effect of some parameters such as acid concentration, the leaching agent amount /stoichiometry amount or excess of acid were applied/, reaction time and temperature on the process. The investigation was performed as a active experiment according to Hartley's plan. The process optimisation procedure was based on the fuzzy logic system. Mainly, the parameters such as magnesium leaching efficiency and zinc losses were taken into account. It was stated that the highest magnesium leaching efficiency of 77.8% with low Zn-losses was reached when H2SO4 solution concentration was 2.5% for 20%-excess of acid, at temperature 25°C and process time of 1 hour.

4

Purification of sphalerite concentrate in the chemical and flotation way

Jarosiński A.

Polish Journal of Chemical Technology

|

2008

|

Vol. 10, nr 4

20-24

EN

In this paper the results of the investigation of magnesium removal, from zinc concentrate derived from zinc-lead ore enrichment plant, have been presented. The characteristics of the initial concentrate and the occurrence forms of dolomite in this material are estimated. It was found that magnesium is collected in the finest fraction of the initial material. The influence of chemical treatment and flotation on the quality improvement of zinc concentrate is determined. This method permits to obtain zinc concentrate containing below 0,3% Mg and about 0,7% Ca.

5

Application of sulphuric(VI) acid leaching for magnesium removal from zinc concentrate

Jarosiński A., Fela K.

Polish Journal of Chemical Technology

|

2007

|

Vol. 9, nr 2

19-22

EN

In this paper the results of investigation of magnesium removal from raw zinc concentrate have been presented. The raw materials derive from ZG Trzebionka and ZGH Bolesław. The differences in zinc and magnesium contents are characteristic of these materials. The experiments were carried out in the periodical reactor at 25°C using the H2SO4 solution of 20, 50, and 70% (v/v) concentration. The weight ratio of the solid phase to the liquid phase was 1:10 and 1:2. On the basis of the experimental results it can be stated that the application of sulphuric(VI) acid leaching permits to increase the zinc yield in Zn-Pb ore processing. This method permits to obtain zinc concentrate containing more than 60% Zn and MgO below 0.3% and CaO about 1.4%.