7th Industrial Minerals Symposium and Exhibition / 25-27 February 2009, Kusadasi, Izmir, Turkey 241 Editors: U. Ipekoglu, A.H. Deliormanli, S. Sen, G. Akar, D. Karakus ÖZET Bu çalışmada apatit tanelerinin flotasyon performansı (verim ve tenör) toplayıcı oranı, miktarı, pH, bastırıcı miktarı, bastırıcı ile kondisyonlama süresi, toplayıcı ile kondisyonlama süresi, köpük alma süresi, katı oranı gibi parametrelerin etkilerine bağlı olarak araştırılmıştır. Testler Taguchi dikey test dizayn yöntemine uygun olarak (L27) dizayn edilmiştir, elde edilen veriler DX 7.0, Minitab 14.0 and WinRobust 1.02 programları ile her bir parametre kullanılarak optimize edilmiştir. En yüksek P2O5 verim ve tenör değerleri % 10 toplayıcı oranı ve 630 g/t toplayıcı tüketim değeri pH 9, 440 g/t bastırıcı tüketimi, 7 dak. bastırıcı ile kondisyonlama, 3 dak. toplayıcı ile kondisyonlama, 5 dak. köpük oluşumu süresi ve % 22 katı oranı ile elde edilmiştir. ABSTRACT The flotation performance (recovery and grade) of apatite particles in a Esfordi Phosphate Complex was investigated as a function of collectors' ratio and dosage, pH, depressant dosage, depressant conditioning time, collectors conditioning time, frothing time and solid percent. The experiments were conducted according to a Taguchi orthogonal array design (L 27 ). The collected data were analyzed by using DX7.0, Minitab 14.0 and WinRobust 1.02 softwares for evaluation the effect of each parameter on the optimization criterion. The highest P 2 O 5 recovery and grade obtained with collectors' ratio and dosage of 10% and 630 g/ton, pH 9, depressant dosage of 440 g/ton, depressant conditioning time of 7 minutes, collectors conditioning time of 3 minutes, frothing time of 5 minutes and 22% solid percent. 1 ITRODUCTION Fertilizers are increasingly important to improve crop yields needed to feed a growing world population. They are natural and manufactured chemicals containing nutrients, such as phosphorus, which are known to improve soil fertility. Phosphorus is an essential element for plant and animal nutrition and has no substitutes in agriculture. Phosphate rock is the only economical source of phosphorus for manufacturing phosphatic fertilizers and chemicals (USGS, 1999). Phosphate rocks are primarily composed of the apatite group in association with a wide assortment of accessory minerals, mainly fluorides, carbonates, clays, quartz, silicates, and metal oxides (Zafar et al., 1995). So phosphate rocks require processing to reduce the content of these impurities. For example, in fertilizer industry it is necessary for the phosphate ores to have: (1) P 2 O 5 content larger than 30%, (2) CaO/P 2 O 5 ratio smaller than 1.6, and (3) MgO content less than 1% (Sis & Chander, 2003). Apatite flotation is difficult due to its physicochemical properties being similar to other minerals present in phosphate ores (Feng & Aldrich, 2004; Oliveira et al., Taguchi Yöntemi ile Apatit Flotasyonunun Optimizasyonu Optimization of Apatite Flotation Using Taguchi Method Hamed Haghi, Azam Ghadyani School of Mining Engineering, University of Tehran, Tehran, Iran Behrang Biranvand Science & Research Campus, Islamic Azad University, Tehran, Iran Seyd Ziaeddin Shafaei Shahrood University of Technology, Shahrood, Iran