EFFECT OF COAGULANTS AND FLOCCULANTS ON DEWATERING OF KAOLIN SUSPENSIONS

Year 2018, , 297 - 305, 31.01.2018

Vildan Önen Muhammed Göçer Hasan Ali Taner

https://doi.org/10.28948/ngumuh.386810

Cited By: 1

Abstract

   Kaolin tailings are commonly generated in the mineral
industry. They are invariably negatively charged and consequently tend to form
stable dispersions with poor flocculation characteristics. Coagulation–flocculation treatments are suitable methods
for removing colloidal particles from wastewater. In this study, the effects of
mono/multivalent ions (coagulants) and polymers (flocculants) on the sedimentation and electrokinetic behaviours of kaolin have been
investigated. In experimental studies, Al₂(SO₄)₃,
FeCl₃, MgCl₂, CaCl₂, NaCl were used as
coagulant, while as flocculant anionic (A150), cationic (C521) and nonionic
(N100) polymers were used. Isoelectric point of kaolin was determined as pH 4.2. The effectiveness of
coagulants increased with the increase in the ionicity degree of the metal
ions. Among the coagulants, FeCl₃ provided the highest efficiency
(91%). Low sedimentation velocities (6.3-12.2 mm/min) were obtained with
coagulants. The highest sedimentation efficiency (94%) was achieved with
anionic flocculants and the same sedimentation velocity (58 mm/min) was reached
with all flocculants. 

Keywords

Kaolin, dewatering, polymer, metal salts, zeta potential

KAOLEN SÜSPANSİYONLARININ SUSUZLAŞTIRILMASINDA KOAGÜLANT VE FLOKÜLANTLARIN ETKİSİ

Abstract

   Kaolin atıkları
mineral endüstrisinde yaygın olarak üretilir. Negatif yüklü olan bu atıklar
zayıf flokülasyon özelliklerine sahip kararlı dağılımlar oluşturmaya
eğilimlidirler. Koagülasyon-flokülasyon işlemleri, koloidal
parçacıkları atık sulardan uzaklaştırmak için uygun yöntemlerdir. Bu çalışmada,
mono/multivalent iyonların (koagülant) ve polimerlerin (flokülant) kaolenin
çökelme ve elektrokinetik davranışlarına etkisi araştırılmıştır. Deneysel
çalışmalarda, koagülant olarak Al₂(SO₄)₃, FeCl₃,
MgCl₂, CaCl₂, NaCl ve flokülant olarak, anyonik (A150),
katyonik (C521) ve noniyonik (N100) polimerler kullanılmıştır. Kaolenin sıfır
yük noktası pH 4.2 olarak belirlenmiştir. Koagülantların etkinliği, metal
iyonlarının iyoniklik derecesinin artması ile artmıştır. Koagülantlar arasında
FeCl₃ en yüksek verimi (%91) sağlamıştır. Koagülantlar ile düşük sedimantasyon
hızları (6.3-12.2 mm/dk) elde edilmiştir. En yüksek sedimantasyon verimliliği
(%94) anyonik flokülant ile sağlanmış ve tüm flokülantlar
ile yaklaşık olarak aynı çökelme hızına (58 mm/dk) ulaşılmıştır.

Keywords

Kaolen, susuzlaştırma, polimer, metal tuzları, zeta potansiyeli

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