Siyanürlü çözeltiden cıvanın uzaklaştırılması

Year 2019, Issue: 4, 30.06.2019

Sadiye Kantarcı , İbrahim Alp

Abstract

Altın/Gümüş
minerallerini içeren cevher yataklarında çoğunlukla belirli bir miktarda ağır
metal ve toksisitesi yüksek olan cıva bulunmaktadır. Altının siyanür ile
muamelesi esnasında altın ve gümüşle birlikte cıva da liç edilmektedir.
Cıva-siyanür kompleksleri çok kararlı olduklarından liç çözeltisinde ve liç
işlemini takip eden proseslerde kirliliğe sebep olmakla birlikte çevre ve
sağlık açısından tehlike arz etmektedir. Bu nedenle cıvanın; hızlı, verimli,
düşük maliyetli, seçimli, kararlı ve tehlikeli olmayan ayırma yöntemleri ile
uzaklaştırılması ekonomik ve çevresel açıdan oldukça önemlidir. Bu çalışmada;
altın, gümüş ve cıva içeren siyanürlü liç çözeltilerinden sodyum sülfür (Na₂S),
sodyum dietilditiyokarbamat (Na-DDC) ve amonyum pirolidin ditiyokarbamat (APDC)
kullanımıyla çöktürme ile cıva uzaklaştırma araştırılmıştır. Ayrıca koagulant
(FeCl₃) ve flokulant (Superfloc A130) ilavesinin cıva uzaklaştırma
verimine etkisi incelenmiştir. Çöktürme ile uzaklaştırmada APDC kullanımıyla
%98,9 verimle Hg konsantrasyonu 8.0 mg L⁻1’ den 0.087 mg L⁻1’ ye düşürülmüştür.

Keywords

Altın cevherleri, siyanürleme, cıva, uzaklaştırma

Removal of mercury from cyanide solutions

Abstract

The
gold/silver ores contain certain amount of mercury, which is a heavy metal and
has high toxicity. During the treatment of gold with cyanide, mercury is also
leached with gold and silver. Since mercury cyanide complexes are very stable,
they cause contamination in leaching solution and are dangerous for the
environment and health. For this reason, removal of mercury by fast, energy
efficient, low cost, selective, stable and non-hazardous separation methods is
very important in economic and environmental terms. In this study; removal of
mercury from cyanide leach solutions were investigated using sodium sulfide (Na₂S),
sodium diethyl dithio-carbamate (Na-DDC) and ammonium pyrrolidine
dithio-carbamate (APDC) as precipitant by precipitation. In addition, the
effect of coagulant (FeCl₃) and flocculant (Superfloc A130) addition
on mercury removal efficiency was investigated. With the use of APDC, Hg
concentration was decreased from 8.0 mg L⁻1 to 0.087 mg L⁻1 in a yield of
98.9%.

Keywords

Gold ores, Cyanidation, Mercury, Removal

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