Pressure leaching of Sivrihisar-Yunus Emre nickel laterites

Seçen, Berk
The aim of this thesis study was to extract nickel and cobalt from Sivrihisar limonitic nickel laterite ore by high pressure acid leaching (HPAL) method under most economical operating parameters. Optimizing the conditions to yield a saleable quality mixed hydroxide product from the pregnant leach solution (PLS) was also investigated. To extract high amounts of nickel and cobalt from the laterite matrix; leaching duration, leaching temperature and sulfuric acid/ore ratio were studied at fixed conditions of -850 µ limonitic ore particle size and 40% solids concentration. The Sivrihisar limonitic nickel laterite ore was found to be readily leachable. It was found that 95.4% of Ni and 91.5% of Co were extracted at the optimized conditions of 235oC, 0.23 acid/ore ratio in 60 minutes. The real pregnant leach solution produced at the optimized conditions of HPAL was purified in two iron removal stages under the determined optimum conditions. Nearly all of the Al and Cr were removed from the PLS in the two stages of iron removal. Then, nickel and cobalt were taken out from the PLS in the form of mixed hydroxide precipitates (MHP) in two stages. A MHP 1 product containing 33.41 wt.% Ni, 2.93 wt.% Co was obtained with a Mn contamination of 3.69 wt.% at the optimized conditions of pH=7, 50oC and 60 minutes. The MHP 1 product was also contaminated with Fe (2.83 wt.%) since it could not be completely removed from the PLS without the critical losses of nickel and cobalt during the two iron removal stages.


Pressure leaching of Çaldağ lateritic nickel ore
Önal, Mehmet Ali Recai; Topkaya, Yavuz Ali; Department of Metallurgical and Materials Engineering (2013)
The purpose of this study was to investigate the process optimization of combined high pressure acid leaching (HPAL) and mixed hydroxide precipitation (MHP) route for the extraction of nickel and cobalt from Çaldağ lateritic nickel ore. In order to extract nickel and cobalt values into pregnant leach solution (PLS), several process parameters of HPAL including acid load, temperature, leaching duration and particle size were investigated in comparative manner at constant solid concentration and agitation spe...
Pressure acid leaching of Caldag lateritic nickel ore: An alternative to heap leaching
Onal, Mehmet Ali Recai; Topkaya, Yavuz Ali (Elsevier BV, 2014-02-01)
In this study, the leachability of Caldag lateritic nickel ore under high pressure acid leaching (HPAL) conditions was investigated. Several HPAL parameters were tested in a comparative manner since in many cases, the extraction efficiencies of Caldag ore sample were more than 90% for nickel and cobalt. After the optimization of the process parameters, it was found that 94.1% nickel and 94.0% cobalt could be extracted under the conditions of 325 kg sulfuric acid/tonne of dry ore, 250 degrees C leaching temp...
High pressure acid leaching of a refractory lateritic nickel ore
MUTLU KAYA, SEVCAN; Topkaya, Yavuz Ali (2011-09-01)
This paper describes the experimental findings of the extraction of nickel and cobalt by high pressure acid leaching (HPAL) of a refractory limonitic nickel laterite ore from the Gordes region of Manisa in Turkey. By optimizing the basic HPAL process parameters: leaching at 255 degrees C with 0.30 sulfuric acid to ore weight ratio with a particle size of 100%-850 mu for 1 h of leaching, it was found that 87.3% of nickel and 88.8% of cobalt present in the ore could be extracted into the pregnant leach soluti...
Nickel resource setimation and reconciliation at Türkmençardağı laterite deposits
Gençtürk, Bilgehan; Karpuz, Celal; Department of Mining Engineering (2012)
In recent years nickel is mostly produced from lateritic ore deposits such as nontronite, limonite, etc. Resource estimation is difficult for laterite deposits as they have a weak and heterogeneous form. 3D modeling software are rather suitable for deposits having tabular or vein type ores. In this study the most appropriate estimation technique for resource estimation of nickel laterite deposits was investigated. One of the known nickel laterite deposits in Turkey is located at Türkmençardağı - Gördes regi...
Hydrochloric acid pressure-oxidation of a pyrite concentrate from the Vaal Reefs East Gold Mine
Topkaya, Yavuz Ali (1999-04-01)
The extraction of refractory gold from pyrite concentrate by hydrochloric acid pressure oxidation was investigated on laboratory scale. The aim was for direct solubilization of refractory gold by chloride pressure-leaching without cyanidation.
Citation Formats
B. Seçen, “Pressure leaching of Sivrihisar-Yunus Emre nickel laterites,” M.S. - Master of Science, Middle East Technical University, 2011.